Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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B~CKG~OUND OF T~E INVENTION
This invention relates in general to applying
twist-type ribbons to bags and more particularly to a
machine for tying such ribbons around the necks of bags.
Many bakery products, particularly bread loaves
and to a lesser measure rolls and buns, are sold in plastic
bags which are gathered at their ends and secured with a
plastic clip or a twist-type tie. Users prefer the twist-
type tie, because it secures the gathered end more tightly
and is easier to reapply once removed. Indeed, the typical
twist-type tie constitutes nothing more than a paper or
plastic ribbon having a thin wire embedded within and ex-
tending longitudinally through it midway between its sides.
While the twist-type tie may be easy for the user to reapply,
it is not so easy for the bakery to apply in the first
instance, for the packaging lines of bakeries operate at
high speeds. A machine exists for applying such ties to
bags as they pass along a conveyor, but this machine
operates relatively slowly, is expensive, and is not entirely
reliable. That machine forms the subject matter of U. S.
patent 3,138,904 to E. Burford.
DESCRIPTION OF T~lE DR~WINGS
In the accompanying drawings which form p~rt of
the specification and wherein like numerals and letters
refer to like parts wherever they occur -
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Flg. 1 is a perspective view of a tying machine
construeted in accordance with and embodying the present
invention;
Figs. 2a and b are fragmentary perspective viewsshowing the portion of the maehine containing the tying
path and also a conveyor for advancing bagged products
past the maehine, with Fig. 2a illustrating the elamping
bar of the maehine in its retracted position and Fig. 2b
illustrating the elamping bar in its elevated position in
whieh it elamps the bag neck;
Fig. 3 is a seetional view of the machine in plan
taken along line 3-3 of Fig. 1;
Fig. 4 is a seetional view in elevation taken
along line 4-4 of Fig. 3;
Figs. 5a, b, e, and d are front sectional views
taken along line 5-5 of Fig. 4 and showing the eomponents
of the machine at various stages in the tying process;
Fig. 6 is a rear seetional view of the machine
taken along line 6-6 of Fig. 3;
Fig. 7 is a perspeetive view showing the ribbon
holder, the twister hook and the ribbon stripper',
Figs. 8a and b are plan views taken along line
8-8 of Fig. 7 and showing the bar of the ribbon holder in
the two positions by whieh it clamps and secures the end of
the ribbon;
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Figs. 9a and b are perspective views of the ribbon
holder with the latter showing the holder path broken away
and in section;
Fig. 10 is an exploded perspective view showing
the mechanism by which twist-type ribbon is fed to the
ribbon holder;
Fig. 11 is a front elevational view of the bag
pusher;
Fig. 12 is an exploded perspective view showing
the tabs of the bag pusher and the means by which they are
connected to the endless chain;
Fig. 13 is a fragmentary perspective view showing
the bag pusher; .
Fig. 14 is a fragmentary perspective view showing
the shafts and gears which power the endless chain;
Fig. lS is a sectional view taken along line 15-15
of Fig. 14 but showing the antirotation plates for locking
the drive shaft that powers the endless chain; and
Fig. 16 is a fragmentary perspective view showing
the various shafts and gears which comprise that portion
of the drive train which is powered by the tying head shaft.
DETAILED DESCRIPTION
. .
Referring now to the drawings, a tying machine A
(Fig. 1) applies twist-type ties t (Fig. 5d) to the ends
of bags B (Fig. 2), each of which containing a product
which was inserted into it prior to the application of the
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tie t. Indeed, the ties t, which are derived from a
ribbon r (Fig. 1), are usually applied to the bags B at
the end of a bagging line in which the products are inserted
into the bags B. Thus, at the end of the bagging line the
bag B extends over and behind the product, and further
projects beyond the product in the form of a neck n (Figs.
2 & 5), The machine A pulls the projecting neck n to cause
the bag B to draw over the product, and further gathers
and clamps the neck n. With the bag B so disposed the
machine A applies the tie t quite close to the product, so
that once the machine A releases its grip on the bag B,
the bag B remains tightly drawn over the product. The
machine A operates on a demand basis, and wraps and twists a
tie t only after it senses that the end of a bag B has
passed a certain location in the machine A. Indeed, the
machine A is designed primarily for use along a conveyor
line C (Fig. 2) that moves bagged products with the ends
of their bags B~projecting laterally beyond the conveyor C,
at least at the region of the conveyor where the tying
machine A is located.
The tying machine A includes a pedestal 2 (Fig. 1)
and a frame 4 which is supported on the pedestal 2 generally
at the level of the conveyor C where it is enclosed in a
cabinet 6 having side walls 8 that are bolted to the frame 4.
The frame 4 includes two lower frame members 10 (Fig. 4)
which extend from the front to the rear of the machine A,
the front in this context being that end of the machine A
into which the neck n of a bag B is projected to ha~e a
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twist-type tie t placed around it. The lower frame members
10 are in turn attached to the pedestal 2. In addition,
the frame 4 includes a center plate 12 which is received in
upwardly opening notches formed in the lower members 10
and extend upwardly therefrom for the full height of the
machine A. The upper edge of the center plate 12, on the
other hand, fits into notches formed in a pair of upper
frame members 14 which likewise extend from the front to
the rear of the machine A directly above the lower frame
members 10. Aside from the pairs of upper and lower frame
members 10 and 14 and the center plate 12, the frame 4
aLso includes a rear plate 16 and lower and upper front
plates 18 and 20. The rear plate 16 is bolted securely
to the ends of the upper and lower frame members 10 and 14
and as such extends the full height of the machine A. The
lower front plate 18, on the other hand, extends only
about one-half the height of the machine A, it being bolted
near its lower edge to the front ends of the lower frame
members 10, while near its upper edge it is fastened to
spacer bars 22 ~Fig. 5) which extend between it ~nd the
center plate 12. The upper front plate 20, while being
directly above the lower front plate 18, is spaced slightly
above the lower plate 18 so that a gap exists between the
two plates 18 and 20. Near its upper edge, the upper plate
20 is bolted against the ends of the upper frame members 14,
while at its lower left hand corner it is bolted against
a spacer bar 24 which extends between it and the center
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plate 12~ Midway between the two upper frame members 14,
another spacer bar 26 (Fig. 3) extends between the center
plate 12 and the upper front plate 20. Thus, the rear
plate 16 and the two front plates 18 and 20 are parallel
to the center plate 12.
The gap between the lower and upper front plates
18 and 20 represents a bag path p (Figs. 4 & 5) through
which the necks n of the bags B pass, one after the other,
and to accommodate such bag necks n, the path p opens out
of the front of the machine A as well as out of each side
wall 8. Moreover, the path p extends inwardly to the
vertical center plate 12. Indeed, as the bags B are advanced
in succession past the machine A on the.conveyor C, the
loose necks n of the bags B enter the path p at one side
of the machine.and are discharged from the path at its
other side and while the neck n of any bag B is within the
path p, the remainder of the bag B, that is the por$ion
containing the product, lies beyond the front of the machine
A~ indeed on the conveyor C which advances the bag B (Fig. 2).
The lower surface of the path p, at least at the,feed end
of the path p, is formed by a horizontal platen 28 (Figs.
2 & 4) which rests on the upper edge of the lower front
plate 18 and extends rearwardly to the vertical center
plate 12 to which it is also secured. ~ctually, the platen
28 is divided into two segments which are separated by a
diagonally extending opening. On the other hand, the upper
surface of the path p is at the feed end formed by a relatively
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narrow bag guide 30 which is bolted to the upper front
plate 20 of the frame 4. The leading end of the bag guide
30 (Figs. 2 & 5) that is the end closest to the feed end of
the path p is tapered downwardly at a slight angle to the
horizontal platen 28. Both the bag guide 30 and the platen
28 lead up to a tying zone z (Figs. 2 & 5) that is generally
midway between the feed and discharge ends of the path p,
and here each bag B is brought to rest with its neck n
somewhat gathered. When the bag B is so disposed, the
ribbon r is placed around its neck n (Figs. 5~, c) then
twisted to secure it to the neck n, and finally cut so as
to leave the bag B with a twist tie t (Fig. 5d) around its
neck n. Thereafter, the bag B is again moved a~ong the -
path p and discharged from the machine A.
Bolted against the front face of the lower front
plate is a guide rail 32 (Fig. 2) which extends substantially
the full length of the path p and generally forms the
outer edge of the path p. The guide rail 32 has an outwardly
directed flange which is located slightly below the upper
surface of the platen 28 and a downwardly turned'rib which
lies in front of the lower fxont plate 20.
At the diagonal space between the two sections
of the platen 28, the machine A is provided with a bag drive
34 (Figs. 3, 5 & 6) which grips the loose neck n of each
bag B immediately after the neck n enters the machine A,
and advances the neck n at a substantially greater speed
than the conveyor C on which the remainder of the bag B
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advances, while at the same time pulls the neck n into the
machine A, that is toward the center plate 12, the latter
having the effect of drawing the bag B tightly over the
product. The bag drive 34 extends along the path p to the
tying zone z, and thus the bag neck n remains under its
control for substantially all of that portion of the path p
which precedes the tying zone z.
The bag drive assembly 34 includes upper and lower
units 36 and 38 which are basically the same, in that
each includes a carrier plate 40 and head and tail pulleys
42 and 44 on that plate. The pulleys 42 and 44 are grooved
and accommodate endless belts 46 which are preferably formed
from polyurethane in a circular cross-sectional configuration.
Indeed, the grooves of the two pulleys 42 and 44 while
conforming to the circular cross sections of the belts 46,
are not nearly as deep as the belts 46 are thick, so the
belts 46 project beyond their respective pulleys 42 and
44. While the pulleys 42 and 44 are on one side of the
carrier plate 40, that is the side which faces the conveyor
C the carrier plate 40 has a small gear motor 48 mounted on
it against its opposite face. The gear motor of the upper
unit 36 is coupled to the, head pulley 42 for rotating the
same, while the gear motor 48 for the lower unit 38 drives
another pulley 49 (Fig. 5a) that is between the head and
tail pulleys 42 and 44 of that unit. The speed of the
motors 48 may be varied, but they are generally set to
advance their respective belts 46 at 2-1/2 to 3 times the
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speed of the conveyor C. In other words, the belts 46
should move at between about 180 and 220 ft/min.
The carrier plate 40 of the lower unit 38 is
secured to the platen 28 in a fixed position with respect
to the path p, such that the upper passes of the belts 42
are parallel to and project slightly above the upper
surface of the platen 28. Moreover, the carrier plate 40
is cocked somewhat with respect to front plates 18 and 20
so that upper passes of the belts 46 are skewed in the path p.
Preferably, the angle between the upper passes of the belts
46 and the front plates 18 and 20 is about 25. Thus, as
the neck n of a bag B passes over the platen ~8, it will
come into contact with the belts 46 at the uppe~ passes
thereo~,
While the lower unit 38 is mounted in a fixed
position on the platen 28, the upper unit 36 is free to
move upwardly and downwardly relative to the platen 28 and
path p, yet is restrained both longitudinally and laterally,
this being achieved by means of a generally horizontal
pivot link 50 ~Figs. 3 ~ 6) which extends betweep the
carrier plate 40 for the upper unit 36 and a block 52
which is attached to the center plate 12. Since the link
50 is connected to both the carrier plate 40 and the block
52 at pivot pins., the upper unit 36 may be raised and
lowered and may further be pivoted at either end upwardly
or downwardly with respect to the lower unit 38. The pulleys
42 and 44 of the upper unit 36 lie directly above the
corresponding pulleys 42 and 44 of the lower unit 38 so that
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the lower passes of the belts 46 on the upper unit 36 are
parallel to the upper passes of the belts of the lower unit
38. However, the grooves in the pulleys 42 and 44 for the
upper unit 36 are offset slightly with respect to the
grooves for the pulleys 42, 44 and 49 of the lower unit 38,
with the offset being such that the belts 46 of the upper
unit 36 fit between the belts 46 of the lower unit 38.
Of course, the motors 48 of the two units 36
and 38 drive the belts 46 of those units such that the
adjacent and parallel passes - that is the upper pass of
the lower unit 38 and the lower pass of the upper unit 36 -
move in the same direction, and that direction is toward
the tying zone z. Thus, when the neck n of a bag B moves
across the platen 28, its leading edge will after a short
distance pass into the nip formed by the uppe~ and lower
belts 46 as they come around their respective head pulleys
42. Being offset and somewhat meshed, the belts 46 grip
the bag neck n and advance it rapidly over the platen 28 -
indeed more rapidly than the conveyor C on which the bagged
products are transported. As a consequence, the'neck n is
brought ahead of or at least even with the leading face
of the bag B and is discharged at the tying zone z in that
condition. The bag neck n discharges against the ribbon r
and thus tends to gather on the platen 28 behind the
ribbon r, yet immediately ahead of the feed assembly 34.
Moreover, by reason of the skew in the meshed passes of
the two sets of belts 46, the belts 46 while they grip
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and advance the bag neck n also move the neck n toward the
center plate 12, and this of course causes the bag B to
draw snugly over the pxoduct, so that the bag B will not
be loosely fitted after the twist tie t is secured.
Even though the belt grooves of the pulleys 42
and 44 for the two drive units 36 and 38 are offset so
that the parallel passes of the belts 46 mesh, the two
head pulleys 42 have somewhat wider grooves which align,
and these grooves, at the nip between the two pulleys 42
accommodate a sensor arm 54 (Figs. 5 & 6) that projects
into the nip from below the platen 28. Actually the sensor
arm 54 forms part of a bag sensor 56 which also includes
a housing 58 that is bolted against the underside of the
platen 28. Indeed, the sensor arm 54 is attached firmly
to the shaft 60 which within the housing 58 is counter-
balanced and spring biased such that its free or upper end
is urged upwardly to project through an opening in the
platen 28 and into the nip at the head pulleys 42 unless
otherwise restrained. When the shaft 60 rotates through
a prescribed angle, which is quite small, it causes a beam
of light within the housing 58 to be interrupted, and this
interruption generates a signal which is transmitted by a
fiber-optic cable to a logic module (not shown) on the
center plate 12. Thus, as a bag neck n is gripped by the
belts 46 at the nip formed at the two head pulleys 42,
the leading edge of the neck n will drive the sensor arm 54
downwardly, causing the shaft 60 to rotate. The arm 54
remains down f or as long as the bag neck n is over it,
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but once the trailing edge of the neck n passes beyond the
nip and arm 54, the arm 54 swings upwardly, and the bag
sensor 56 generates a si~nal. Hence, the sensor 56 not
only detects the presence of a neck n along the path p,
but also detects when the neck n clears a specific point in
the path p.
At the tying zone z to which the belts 46 drive
the bag neck n, is a ribbon holder 66 (FigsO 5 & 7-9)
which includes a clamping block 68 that is bolted against
the front face of the upper front plate immediately above
the path p, a clamping bar 70 which moves to and fro within
the block 68, and a shear plate 72 which is attached to
the underside block 68. In addition, the ribbon holder 66
includes a double acting air cylinder 74 which is connected
between the clamping bar 70 and the frame 4 so as to move
the bar both ways within the block 68.
More specifically,the clamping block 68 projects
forwardly from the upper front plate 20, and slightly beyond
the exposed longitudinal edge of the guide rail 32 it
has a cavity 76 (Fig. 9) which opens upwardly and also
laterally toward the feed end of the path p. Between the
base of the cavity 76 the bottom of the block 68 is a
clamping slot 78, each side of which constitutes a jaw 80
containing a horizontal groove 82. The slot 78 at its one
end opens out of the ~lock 68 and toward the feed end of
the path p, while at its other end it opens into another
cavity 84 which is occupied for the most part by the clamping
bar 70.
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Indeed, within the cavity 84 the clamping bar 70
is connected to the block 68 by a pivot pin 86 which
extends through the bar 70 and threads into the block 68.
On one side of the pin 86, the bar 70 is tapered and
projects into the clamping slot 78 where on each of its
sides it has a convex rib 90. The tapered sides of the
bar 70 are presented toward the jaws 80 that line the
slot 78 in the block 68, all such that the ribs 90 align
with and conform in configuration to the grooves 82 in the
jaws 80. The arrangement is such that the tapered end of
the bar 70 pivots between the jaws 80, and when against
either jaw 80, the convex rib 90 on that side of the bar 70
will actually enter the aligned groove 82 of the jaw 80.
Should the ribbon r be between the tapered end of the bar 70
and either jaw 80 of the clamping slot 78 as the tapered
end moves toward that jaw 80, the ribbon r will be driven
into the groove 82 of the jaw 80 by the aligned rib 90
on the bar 70, and thereby clamped securely between the bar
70 and the jaw 80.
The bar 70 li~ewise extends beyond the opposite
side of the pivot pin ~6 and indeed out of the other
cavity 84~ Beyond the cavity 84, it is connected to the
air cylinder 74 (Fig. 7) at a clevis. The cylinder 74 extends
through the upper front plate 20 and behind that plate is
connected to the center plate 12 through another clevis.
Thus, when the piston rod of the cylinder 74 is extended,
the tapered end of the clamping bar 70 moves toward and
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529
perhaps against the jaw 80 located closest to the surface
of the upper front plate 20 (Fig. 8b). Conversely, when the
piston rod is retracted, the tapered end of the bar 70 moves
toward and perhaps against the opposite jaw 80 (Fig. 8a).
In any event, the tapered end of the bar 70 is always at one
jaw 80 or the other, leaving space in the clamping slot 78
for reception of the ribbon r. After the ribbon r is
brought up to and inserted into that space, the cylinder 74
is energized to move the tapered end of the clamping bar 70
toward the opposite side jaw 80, and as a consequence the
ribbon r is clamped between the bar 70 and that opposite jaw 80.
The shear plate 72 lies beneath the clamping block
68 to which it is bolted, and it contains a cutout 92
(Fig. 9) that is directly below the clamping slot 78, so
that the clamping slot 78 opens downwardly through the cutout
92. The sides of the cutout 92 are set slightly inwardly
from the surfaces that form the jaws 80 and are further
beYeled so as to present cutting edges 94 which are exposed
at the bottom of the clamping slot 78. Moreover, the lower
surface of the clamping bar 70, at least at its tapered end,
is planar and wipes across the cutting edges 94 as the bar
70 pivots to and fro between the jaws 80 of the block 68.
Hence, as the tapered end moves toward either jaw 80 to clamp
the ribbon r, its lower surface will, before the clamping is
effected, wipe across the cutting edge 94 below that jaw 80
and sever the ribbon r at that location. Even though the plate
72 is bolted to the clamp block 68, a slight space or gap exists
between the plate 76 and the block 68, at least in the region
of the clamping slot 78 for the block 68 and the cutout 92 of
the plate 72. The gap allows lint derived from the ribbon r to
pass outwardly away from the cutting edges 94 so that it does not
accumulate in the cutout and disrupt the operation of the ribbon
holder 66.
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In summary, the clamping bar 70 simultaneously
cuts and clamps the ribbon x each time the air cylinder 74
causes the bar 70 to pivot about the axis of the pivot pin
86 - assuming of course that the ribbon r prior to the
rotation of the bar 70 is extended through the clamping slot 78
in the block 68 and the underlying cutout 92 in the shear
plate 74 - and this holds true irrespective of the direction
in which the bar 70 is rotated. The portion of the ribbon r
which is severed falls free of the ribbon holder 66 and
constitutes a tie t for securing the neck n of a bag B. The
clamped portion of the ribbon r, on the other hand, constitutes
the very end of an extended length of ribbon r which passes
obliquely through the path p at the tying zone z. Indeed,
the neck n of the next bag B that is to be tied is brought
against the obliquely extending portion of the ribbon r
where that neck n tends to gather by reason of the obstruction
created by the ribbon r.
The ribbon r, which at its end is gripped and held
by the ribbon holder 66, pays off of a reel 100 (Fig. 10)
that fits over a spindle 102. The spindle 102 rotates on a
bearing block 104 which is located within the cabinet 6,
yet is mounted on one of the cabinet si,de walls 8, and at the
block 104 is fitted with a brake pulley 106 containing a
V-groove. Upon coming off of the reel 100, the ribbon r
passes under a tension roller 108 which is located at the
end of a ribbon tension arm 110 and thence over an idler
roller 112 which is located somewhat higher than the roller 108
where, in contrast to the tension roller 108, it rotates about
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an axis that is fixed in position on the cabinet wall 8.
~loreover, the ribbon tension arm 110 is directed generally
away from the idler roller 112 so that any tension within
the ri~bon r tends to draw the roller 108 and its arm 110
toward the idler roller 112. The tension arm 110 extends
from a shaft 114 to which it is firmly clamped, and the
shaft 114 is par~llel to but located below the spindle 102
where it rotates in a bearing block that is mounted on the
cabinet wall 8. ~t its inner end the shaft 114 is fitted
with a brake arm 116, and the brake arm 116 is in turn
connected by means of an adjustable link 118 to.an elongated
slide 120 that extends upwardly along the.inside face of the
cabinet wall 8 toward the brake pulley 106 of the spindle 102.
The slide 120 contains longitudinal slots 122 through which
guide pins 124 pass, those pins being secured to the inside
face of the cabinet wall 8. Each pin 124 has a shoulder
and a head where it is received in its respective slot 122
so that the two pins 124 prevent the elongated slide from
moving laterally within the cabinet, but do not impede
longitudinal or vertical movement of the slide 120 toward
and away from the brake pulley 106 within the confines of
the slots 122, of course. ~t its lower end the slide 120
contains another slot 126 through which another pin 128
passes, this pin further extending through the upper end of
the adjustable link 118 for connecting the link 118 to the
slide 120. ~t its upper end, the slide 120 is attached to a
brake belt 130 which loops over the brake pulley 106 in
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the V-groove thereof and is secured in an anchor w~liah is
mounted on the bearing block 104. Friction occurs between
the pulley 106 and the belt 130, and this has the effect
impeding rotation of the spindle 102, causing greater
tension in the ribbon r as it pays off of the reel 100.
Adjacent to the brake actuator arm 116, the shaft
114 is fitted with a control arm 132 to which the end of
an air cylinder 134 is connected, the opposite end of the
cylinder being on the cabinet wall 8 itself. ~ir at a
selected pressure is delivered to the cylinder~134 which,
acting through the control arm 132, applies a torque to the
shaft 114~ and this torque is resisted by the ribbon r
as it loops under the tension roller 108. Should the ribbon r
break or detach from the ribbon holder r, it will no longer
offer any resistance to the tension arm 110, and the air
cylinder 134 will cause the shaft 114 to rotate. ~s a result,
the adjustable link 118 will drop downwardly until the pin
128 which connects it to the slide 120 bottoms out in the
slot 126 of the slide 120. When this occurs, the torque
exerted on the shaft 114 by the air cylinder 134,is resisted
at the slide 120 and brake belt 130. Thus, the belt 130
applies a braking force to the spindle 102 to prevent the
reel 100 from turning and discharging unneeded ribbon r.
On the other hand, the tension in the ribbon r may
become excessive, and when this occurs, the ribbon r acting
through the tension roller 108 draws the tension arm 110
upwardly. The shaft 114 of course rotates and at its opposite
5~9
end lifts the adjustable link 118. If the rotation is great
enough, the link 118 will bring the connecting pin 128 to
the upper end of the slot 1~6 in the slide 120 and lift the
slide 120, thereby reducing the frictional resistance between
the brake belt 130 and the pulley 106. This in turn relaxes
the tension in the ribbon r.
Beyond the idler roller 112 which is located on the
same side wall 8 as the tension roller 108 and reel 100,
the ribbon r passes over a corner roller 136 located at
one of the front corners of the cabinet ~, and thence along
the lower front plate 18 to a front roller 138 (Fig. 5) wllich
is mounted on the front plate 18 somewhat ahead of and below
the tying zone z. Indeed, the ribbon r loops around the front
roller 138 to extend diagonally upwardly through the path p
and to the ribbon holder 66 where its end is clamped between
the clamping bar 70 and one of the jaws 80 on the clamping
block 68.
While the bag drive 34 moves the neck n of each
bag B toward and into the tying zone z and further pulls the
bag B laterally so as to draw it snugly over the product,
the actual advancement of the bag neck n into the awaiting
ribbon r, that is the segment which extends through the
path p, is effected by means of a bag pusher 148 (Figs. 5
& 11) which in contrast to the bag drive 34 operates inter-
mittently. Indeed, with each actuation of the bag
pusher 148 a different bag neck n is pushed int,o and presented
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at the tying zone z where the awaiting ribbon r is looped
around it, then twisted, and subsequently severed so as to
provide the bag neck n with its own twist tie t.
The bag pusher 148 is for the most part presented
along the front face of the lower front plate 18, that is
along the face of the plate 18 that faces the conveyor C.
It includes an endless roller-type chain 150 w~ich assumes
a somewhat rectangular configuration similar to that of
the lower front plate 18, this configuration being dictated
by four sprockets 152, 154, 156, and 158 over which the
chain 150 passes and with which it is engaged. The two
uppermost sprockets 152 and 154 are located at opposite
corners of the plate 18 and position the upper pass of the
chain 150 immediately below the rib on the outwardly
directed flange of the guide rail 32, which is essentially
at the elevation of the platen 28 over which the major
portions of each bag neck n passes. The two sprockets 152
and 154 rotate on stub shafts which are secured to the front
plate 18, and the same holds true with regard to the sprocket
156 which is directly below the sprocket 152, but the
stub shaft for the sprocket 156 may be adjusted upwardly
and downwardly to control the tension in the chain 150.
~11 three sprockets 152, 154 and 156 are the same diamter
and constitute idlers. The fourth sprocket 158, which is
located directly below the idler sprocket 154, in contrast to
the sprockets 152, 154 and 156, is relatively large and is
mounted on a sprocket shaft 162 ~Figs. 3 & 14) which e~tends
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through and rotates in bearings 164 (Fig. 6) that are mounted
on the lower front plate 18 and the center plate 12. The
drive sprocket 158, however, may be adjusted angularly with
respect to the shaft 162 to control the timing of the pusher
assembly 148.
With regard to that timing, the chain 150 at three
equally spaced intervals has squared off master links 166
(Figs. 11-13), each of which carries a push tab 168 which
normally projects'outwardly from the chain 150. Indeed,
each tab 168 is located against the front face of the
squared off link 166 on which it is carried and has a pin
170 which projects through the link 166 and forms the first
of the two pins 170 for the link 166 (Fig. 12). While the
pin 170 is attached firmly to the tab 168, it rotates easily
within the s~uared off link 166, thus enabling the tab 168 to
pivot relative to the link 166 and the chain 150 of which
it forms a part, assuming of course that the tab 168 is not
otherwise restrained.
The tabs 168 are indeed free to pivot along most
of the chain 150 except in the region between the two upper
sprockets 152 and 154, which is of course wher,e the upper
pass of the chain 150 exists. Here the rollers of the chain
150 pass beneath the downwardly turned rib on the guide
rail 32 and over a track 172 (Fig. 11) which is bolted
against the lower front plate 18 so the chain 150 in this
region is captured between the guide rail 32 and the track
172. ~oreover, any tab 168 in this region of the chain 150
also rides on the track 172 which prevents the tab 168 from
12~529
pivoting rearwardly with respect to the direction of a~vance
for the chain 150. ~lore specifically, each tab 168 is for
the most part a flat plate-like element having the general
configuration of a right triangle, it being attached to the
chain 150 solely by the leading pin 170 for the link 166
along which it is located (Fig. 12). That pin 170 projects
perpendicularly and horizontally from the tab 100 in the
region of its right angle apex. One of the remaining sides
forms the leading edge of the tab 168, at least when the
tab 168 is in an elevated position as it would be over the
track 172, and along the leading edge, the tab 168 has a rib
174 which projects over the link 166 to exist above the
link 166 at the upper pass of the chain 150. ~he rib 174,
provides a pushing surface which is the surface at which the
tab 168 actually comes against the neck n o~ a bag B. While
the rib 174 extends to the free end of the tab 168, it
terminates somewhat away from the link 166, at least when
the tab 168 is in its elevated position on the chain 150.
Even so, the rib 174 extends far enough along the leading
edge of the tab 168, to come against the outer edge of the
link 166 when pivoted rearwardly out of its elevated
position, and indeed when the rib 174 is against the outer
edge of the link 166, the tab 168 is in its retracted position.
Along its remaining side the tab 168 ha~ a shoe
176 (Fig. 12), which like the rib 174 is directed toward
the lower front plate 18, but the shoe 176 lies inwardly
from the chain 150 and is no wider than the outermost plate
of the squared off link 166 so it will pass to the sides of
the sprockets 152, 154, 156, and 158. Indeed, when the tab
168 is in its elevated position, the shoe 176 is against
~\
- ~Z~4 S2~
the inner edge of the squared off link 166 and thus serves
to position the leading edge and rib 174 generally per-
pendicular to that segment of the chain 150 along which
the tab 168 is located. The upper surface of the track
172 is actually at two levels - one for the rollers of the
chain 150 and the other for the shoes 176 of the tabs 168.
Thus, along the track 172 the chain 150 at its rollers is
captured between the rib of the guide rail 32 and the upper
level of the track 172, while any tab 168 along that portion
of the chain 172 is at its shoe 176 captured between the
lower or inside edge of its squared off link 166 and the
lower level of the track 172, yet is free to slide along
the track 172, which it does. This confinement of the
chain 150 and shoe 176 by the guide rail 32 and track 172
holds the tab 168 in its upright or elevated position as the
tab 168 passes over the track 172, and as a consequence
the tab 168 will push any bag neck n that lies ahead of it
on the path p toward the tying zone z. However, the chain
lS0 advances the tab 168 at a velocity less than that of the
belts 46 in the bag drive assembly 34, so the end portion
of the bag neck n which is gripped in the belts 46 of the
bag drive 34 normally leads the portion which is more closer
to the product, which is of course the portion against which
the pusher tab 168 bears. The sprocket shaft 162 rotates
incrementally, and with each incremental advan~e; moves a
different tab 168 ~p to the tying zone z and then abruptly
brings the chain 1-50 and the tabs 168 on it to rest.
That tab 168 which moves into the tying zone z during this
529
incremental advance drives the portion of the bag neck n
that it contacts against the segment of the ribbon r
which extends upwardly through the path p to the ribbon
holder 66 where the end of the ribbon r is secured, the
advance being enough to deflect the ribbon r slightly.
~s a consequence, the bag neck n gathers between the ribbon r
and the tab 168.
The track 172 extends beyond the tying zone z,
so when the chain 150 is again energized, the elevated
tab 168 moves the gathered bag neck n out of the tying
zone z. However, the track 172 terminates prior to the
sprocket 152, and once the tab 168 passes of f of the track
172, it is free to swing backwardly to its retracted
position (Fig. 11). Thus, the tab 168 does not present a
hazard as it passes over the sprocket 152, for it will
merely drop backwardly if it comes into contact with any-
thing.
While the chain 150 is at rest with one of its
tabs 168 in the tying zone z, the neck n of a bag B is
gathered between that tab 168 and the segment of, ribbon r
which extends from the front roller 138 up to the ribbon
holder 66. Indeed, the ribbon r in this region is deflected
somewhat forwardly under the force exerted on the bag neck n
by the tab 168. When the bag neck n is so disposed, it
is held against the underside of the upper bag guide 30 by a
bag neck clamp 180 (Fig. 2) which moves upwardly and down-
wardly in the path p. The bag neck clamp 180 constitutes
~3
5,'~
a horizontal bar which lies below and parallel to the upper
bag guide 30 through substantially the entire tying zone z.
Being directly below the upper bag guide 30, the clamp
180 further lies inwardly from the chain 150 so it does
not interfere with the tabs 168 as they move along the track
172. Furthermore, w}len the clamp 180 is in its lower
position (Fig. 2a), it lies below the upper surface of the
platen 28 and the upper surface of the guide rail 32 as well.
As such, it does not interfere with the bag necks n as they
move over the platen 28. On the other hand, when the clamp
180 is elevated (Fig. 2b) it will approach the upper bag
guide 30 and cause any bag neck n that is within the tying
zone z to be clamped and secured between the clamp 180 and
the underside of the upper bag guide 30.
To effect this movement, the clamp 180 is attached
to a laterally directed bar 182 which pivots on a block 184
secured to the center plate 12. Near the clamp 180, the
bar 182 is connected to the piston rod of a double acting
air cylinder 186, the barrel of the cylinder 186, on the
other hand, being attached to the back face of the lower
front plate 18. Thus, when the cylinder 186 is energized
by admitting compressed air to its head end, the piston
rod will extend and lift the clamp 180 toward the upper bag
guide 30 (Fig. 2b), and indeed the machine ~ is timed so
as to energize the cylinder 186 immediately after the chain
150 pauses with one of its tabs 168 at the tying zone z.
In that condition the neck n of a bag B is gathered between
1;~94S~
one of the tabs 168, and the segment of ribbon r that
passes upwardly through the path p. Moreover, the-
cylinder 186 remains energized to hold the bag neck n
firmly in place a~ the ribbon r is looped around it and
thereafter twisted to create a twist tie t. ~owever,
just as the twist tie t is completed, the cylinder 186 is
energized from its rod end to withdraw the clamp 180
(Fig, 2a~ and thus release the gathered and tied bag neck n
from the underside of t~le upper bag guide 30. In short,
the bag neck clamp 180 prevents the bag neck n from being
lifted upwardly while the ribbon r is looped underneath
it and brought up again to the ribbon holder 66.
The actual looping of the ribbon r beneath the
bag neck n is performed by/ribbon needle 190 ~Fig. 5)
which is located opposite the lower front plate 18 generally
in the region between the idler sprocket 152 for the chain
150 and the front roller 138 for the ribbon r. The needle 190,
which is located beyond the chain lS0 and the tabs 168 on
it~ possesses a somewhat hooked or U-shaped configuration
with the trough of this configuration normally opening
upwardly toward tying zone z. At its end closest to the
sprocket 152 the needle 190 is attached firmly to a shaft
192 which rotates in bearings 194 (Fig. 14~ that are set
on the lower front plate 18 and the center plate 12. The
shaft 192 rotates in an oscillatory manner to move the
needle 190 between a normally retracted position an~ an
elevated position. The opposite end of the needle 190 is
~!~
~ 2~
bifurcated and carries a small needle roller 196 at the
inner ends of the two tines which create the bifurcation,
and of course the roller 196 turns between these tines.
In the region between its bend and its roller 196, the
needle 190 on its backside contains a groove 198 which leads
up to the roller 196.
~ hen the needle 190 is in its normal retracted
position (Fig. 5a), its mounted end as well as its free
end lie beneath the g~ide rail 32, and the ribbon r passes
under the front roller 138 on the plate 18 and thence over
the needle roller 196 to the ribbon holder 66. The needle
roller 196 at the free end of the needle 190 deflects the
ribbon r only slightly. On the other hand, when the
needle 190 is in its elevated position (Fig. 5cj; it tends
to loop generally around the tying zone z, and the needle
roller 196 lies over the upwardly opening cavity 76 in
the clamping block 68. As such it configures the ribbon r
such that the ribbon r passes upwardly through the nPedle
groove 198 to the needle roller 196 and thence downwardly
through the cavity 76 and the clamping slot 78 within the
clamping block 68, as well as through the cutout g2 in the
underlying shear plate 72. Within the slot 78 the ribbon r
lies along one of the sides of the tapered end for the
clamping bar 70. Thus, when the air cylinder 74 is energized,
the bar 70 will bring the ribbon r against one of the
cutting edges 94 for the shear plate 72 so as ~o cut the
ribbon r, and will contemporaneously clamp the portion of
~lo
~2~4S2~3
the ribbon r that is immediately above the cut between the
rib 90 on that side of the bar 70 across which the ribbon r
passes and the opposite jaw 80 in the clamping block 68.
In other words, as the needle 190 moves upwardly out of
its retracted position, it brings the ribbon r beneath the
gathered neck n of the bag B and then upwardly behind that
neck n, so that a segment of ribbon r exists ahead of the
bag neck n and another segment exists behind the ~ag neck n.
The leading segment is at its upper end secured between
one jaw 80 of the clamping block 68 and the clamping bar
70, while the trailing segment is carried upwardly and for-
wardly by the roller 196 of the needle 190 and placed
between the other jaw 80 and the other side of.the clamping
bar 70. The latter segment also extends through the cutout
92 of the underlying shear plate 72. Beyond the trailing
segment, the ribbon r passes over the needle roller 196
and through the groove 1~8 in the back side of the needle
190, and thence to the front roller 138 on the lower front
plate 18. Both segments or the ribbon r, however, lie beyond
the chain 150, so as to be between the product a,round which
the bag B is fitted and the tab 168 that is against the neck n
for t~at bag. With the ribbon r so configured and positioned,
its leading and trailing segments are twisted together to form
the twist tie t and immediately thereafter the clamping bar 70
is shifted to sever the trailing segment and thereby free tlle
tie t that is so created.
The twist is imparted to the two ribbon segments
by a ribbon twister hook 200 (Figs. 5, 7, & 8) which rotates
in the region above the upper bag guide 30 and below the
clamping block 66 of the ribbon holder and shear 66. Each
~1
1~4529
time the needle 190 brings a trailing segment of ribbon r
upwardly to the ribbon holder 66, the hook 200 undergoes
four revolutions about a vertical axis that is presented
slightly outwardly from the upper front plate 20 and indeed
in general alignment with the leading and trailing segments
of ribbon r. At the outset of the first revolution the
hook 200 engages the two segments of ribbon and thereafter
imparts several turns to them so that they are twisted
securely together.
The hook 200 is attached to the lower end of a
vertical shaft 202 (Fig. 7) which rotates in a bearing
~lock 203 (Figs. 4 ~ 5) that is bolted against the front
face of the upper front plate 20. The hook 200 possesses
an arcuate configuration for substantially its entire
length, with the arc so formed lying in a plane that is
perpendicular to the axis of the shaft 202, but where the
hook 200 merges with the shaft 202 a somPwhat narrow notch
204 is formed, and it is within the notch 204 that the
actual twisting occurs. In this regard, the hook 200 when
in its rest position, that is the position from'which it
starts its rotation, has its free end presented generally
toward the discharge end of the path p, and this presents
the convex surface of the hook 200 outwardly toward the
conveyor C on which the bags B move. It is against this
convex surface that the leading segment of ribbon r initially
lies (Figs. 5a, b). The hook 200 turns as the needle 190
rises out of its retracted position, so that as th~ needle
190 brings the trailing segment of the ribbon r into the
slot 78 of the clamping block 68, the concave surface of the
~g
1~4SZ9
hook 200 is presented toward the trailing se~ment - and
the leading segment as well ~Figs. 5b, c).
During the initial revolution for the hook 200
the concave face of the hook 200 gathers the leading and
trailing segments of the ribbon r and brings them inwardly
to the notch 204 where they are side-by-side. As the
rotation continues, the two segments are twisted together,
and after several revolutions, the shaft 202 cornes to rest
with the free end of the hook 200 again pointing toward
the discharge end of the path p. ~hile the twister hoo~
200 is somewhat above the gathered bag neck n, which is
held against the underside of the upper guide 30 by the
bag neck clamp 180, the actual twist occurs against and
immediately above the gathered bag neck n.
Since the hook 200 comes to rest with its free
end presented toward the discharge end of the path p, the
twist tie t is free to move out of the hook 200 once it is
severed from the remainder of the ribbon r, and this occurs
when the clamping bar 70 moves and brings the trailing segment
across one of the cutting edges 94 on the shear'plate 72.
Of course when the clamping bar 70 moves, it releases the
leading segment of ribbon r, and at the time it shears
the trailing segment, it further clamps the portion of the
trailing segment that is above the shear plate 72. That
portion, once the needle 190 retracts, becomes the leading
segment of ribbon r from which the next twist tie t is created.
~q
, . . .. . . . .. ....
~2e~5~'9
At its upper end the shaft 202 on which the twister
hook 200 is mounted is fitted with a bevel gear 206 ~Fig. 4)
which meshes with a larger bevel gear 208 on a horizontal
twister shaft 210 that extends rearwardly throu~h the
upper front plate 20 and the center plate 12 of the frame 4.
Indeed, the plates 12 and 20 are fitted with bearings 212
(Fig. 14) which receive the shaft 210. The bevel gear 208
has four times the number of teeth as the gear 206, so for
each revolution of the twister shaft 210, the vertical
shaft 202 and the twister hook 200 on it undergo four
revolutlons.
After the clamping bar 70 moves over one of the
cutting edges 94 of the shear plate 72 to release the
leading segment of ribbon r and sever the trailing segment,
the completed twist tie t is physically displaced from
the tying zone z, not only by the chain 150 which advances
at about this time, but also by a ribbon stripper 216
(Figs.- 7 & 8) which moves through the tying zone z in
the region between the lower edge of the upper front plate
20 and the upper surface of the upper bag guide'30. ~s such
it passes directly beneath the twister hook 200. The ribbon
stripper 216 projects outwardly from the upper front
plate 20, behind which it is attached to a stripper shaft
220 which turns in a bearing block 222 that is fastened to the
upper front plate 20 against its back face. For the most part
the stripper 216 is straight and flat, but at its free end it
curves forwardly somewhat in the provision of a hook 224.
`~ -
~2~4529
Normally, the stripper 216 is in a rear position
where its hook 224 is located generally within the upper
bag guide 30 and thus does not interfere with the movement
of the ribbon needle 190 upwardly past the front face of
the upper guide 30 to place the trailing ribbon segment in
clamping block 68 of the ribbon holder 66. ~lowever, when
the stripper shaft 220 is turned in the appropriate
direction, the hook 224 of the stripper 216 emerges from
the upper bag guide 30 and proceeds forwardly in an arc,
passing under the twister hook 200 and thence under the
clamping block 68 and the shear plate 72 as it does. Indeed,
the forward movement of the stripper 216 does not cease
until the leading edge and hook 224 on the stripper 216
are beyond the cutout 92 in the shear plate 72. In other
words, when the stripper shaft 220 rotates, the stripper
216 moves over the tying zone z of the path p and will
clear any twist tie t from the region through which it moves.
The forward rotational movement of the stripper
216, and likewise the rearward rotational movement to
return the stripper 216 to its initial position, is derived
from a double acting air cylinder 226 (Figs. 7 & 8) which
is connected between a crank arm 228 on the upper end
of the stripper shaft 220 and a clevis-like mount 230
which is on the front face of the center plate 12. When the
piston rod of the cylinder 226 is retracted, the crank arm
228 is generally perpendicular to the upper ifront plate 20
and the stripper 216 is in its rear position. However,
3\
SZ~
when.the piston rod for the cylinder 226 is extended, the
stripper shaft 220 rotates and moves the stripper 216
forwardly above the tying zone z for the path p. Between
its rear and forward positions, the stripper 216 describes
an arc of approximately 90. ~loreover, the cylin~er 226
is only energized after the twister hook 200 has twisted
the leading and trailing segments of ribbon r together and
the clamping bar 70 has released the leading segment and
severed the ~railing segment to ~ree the compieted twist
tie t from the clamping block 68.
To summariæe the events which occur within the
tying zone z of the path p once the bag drive 34 propels
a generally flat bag neck n past the sensor arm 54, thereby
causing the bag sensor 56 to generate a signal, the drive
sprocket 158 of the bag pusher 148 rotates, causing one
of the tabs 168 on the chain 150 to move over the idler
sprocket 154 and onto the track 172 where it assumes and
maintains its upright or elevated position. The tab 168
moves along the track 172 in its elevated positioll, and as
it does it collects the bag neck n and pushes the neck n
against the segment of ribbon r which rises through the
path and is secured at its end in the clamping block 68
of ribbon holder 66. The bag neck n gathers between the
ribbon r and the rib 174 of the tab 168 and indeed deflects
the ribbon r forwardly by the time the chain 150 comes to
rest with its tab 168 in the tying zone z (Fig. 5b).
_
529
When the chain 150 stops, the air cylinder 186
i5 energized, and it elevates the bag neck clamp 180,
so that the gathered bag neck n is captured between the
clamp 180 and the underside of the upper bag guide 30.
With the bag neck n so clamped, the ribbon needle 190 rises
out of its retracted position and brings the ribbon r beneath
the gathered bag neck n as well as upwardly behind the
bag neck n, thus creating leading and trailing segments at
the tying zone z. Indeed, the ribbon needle 190 moves to
its elevated position (Fig. 5c) in which its roller 196 is
directly above the clamping block 68 of the ribbon holder
66, and when the needle 190 is so disposèd the traiiing
segment extends through the cavity 76 and slot-78 in the
clamping block 68, where it passes along one side of the
tapered end for the clamping bar 70. It likewise extends
through the cutout 92 in the underlying shear platP 72.
The ribbon needle 190 moves harmonically and
dwells momentarily in its elevated or top dead center
position, and while the needle 190 is near and in this
position, the twister hook 200 undergoes four r'evolutions.
During about the first 270 of rotation, the,hook 200
collects both the leading segment and the trailing segment
of ribbon r and brings them inwardly to the notch 204 at
the base of the hook 200 where the two segments are in
juxtaposition. As the hook ~00 continues to rotate, it
twists the juxtaposed leading and trailing segments of the
33
5~3
-
ribbon r together, with the twist commencing at the top
side of the gathered bag neck n and working upwardly
therefrom toward the hook 200 itself.
After about 270 of rotation for the twister
hook 200, the air cylinder 74 for the ribbon holder 66 is
energized to drive the tapered end of the clampinq bar 70
to the opposite jaw 80 in the clamping slot 78 of the
clamping block 68, and as this occurs the bar 70 releases
the leading segment of ribbon r and moves the trailing
segment over the opposite cutting edge 94 on the shear
plate 72, thereby severing the trailing segment. Con-
temporaneously the bar 70 clamps the new end of ribbon r
against the opposite jaw 80 of the block 68, that is the
jaw 80 toward which the bar 70 moves. Thus, a severed
twist tie t remains at the tying zone z (Fig. 5d).
At about the time the twister hook stops, the
cylinder 186 for the bag neck clamp 180 is energized from
its opposite end to retract the clamp 180 from the upper
bag guide 30 and thereby release the formerly secured bag
neck n.
The severed tie t is cleared from the tying zone z
by the ribbon stripper 216 which moves forwardly under the
torque exerted by the air cylinder 226. As the stripper 216
advances, its hook 224 comes against the twisted portion of
the tie t and propels the twisted portion forwardly out from
beneath the cutout 92 in the shear plate 72. ~t the
same time, the drive sprocket 158 resumes rotation and moves
3`~
...
12~ ~5~
the chain 150 so that the elevated tab 168 at the tying
zone z drives the gathered and tied bag neck n forwardly.
Also, the air cylinder 226 is pressuriæed at its opposite
end to move the ribbon stripper 216 back to its original
position where its hook 224 is in effect within the upper
bag guide 30.
Finally the ribbon needle 190 moves back to its
retracted position, and as it does the ribbon r pays off
of the roller 196 at its end. Since the end of the ribbon r
is clamped within the clamping block 68, the needle 190
upon retracting merely leaves the ribbon extended upwardly
through the path p to form the leading segment of the sub-
sequent twist tie t.
The movements of the chain 150, the ribbon needle
190 an~ the twister hook 200 are all derived from an
electric gear motor 234 (Figs. 3, 4 & 6) which is mounted
on two support rods 236 that extend between the center plate
12 and the rear plate 16 of the frame 4, whereas the move-
ments of the clamping bar 70 for the ribbon holder and
shear 66, the bag neck clamp 180 and the ribbon'stripper 216
are derived from their respective air cylinders 74, 186 and
226. To this end, the gear mo~or 234 is coupled through a
drive train 238 to the drive shaft 162 for the sprocket 158
which drives the chain 150, and likewise to the shaft 192
which carries the ribbon needle 190 and the horizontal
twister shaft 210 which through the bevel gears 206 and 208
drive the twister hook 200. Indeed, the shafts 162, 192
~G
94S~'9
and 210 could be considered part of the drive train 238 as
could the sprockets 158 and the bevel gears 206 and 208.
~oreover, each of the air cylinders 74, 186 and 226 is
connected to a source of compressed air through valves 240,
242 and 244 (Fig. 4), respectively, which ars operated by
the drive train 238. Thus, all of the operations or move-
ments which occur at the tying zone z, whether they be
powered by the motor 234 or by the compressed air cylinders
74, 186 and 226, are timed from the drive train 238.
The drive train 238 begins with a chain 246
(Figs. 3, 4, 6, & 14) that wraps around a sprocket 248 on
the gear motor 234 and also around a sprocket 250 on a
primary drive shaft 252 that rotates in bearings 254 (Fig. 5)
attached to the center plate 12 and to the lower front plate
18. Of course, the shaft 252 extends between the two
plates 12 and 18 and further projects rearwardly beyond the
latter, the sprocket 250 being on the rearwar,dly projecting
portion. While the sprocket 250 is mounted on the primary
drive shaft 252, it is not coupled directly to that shaft,
but lnstead is connected to the shaft 252 through a single
revolution clutch-brake 256 (Fig. 3) which operates on
the wrap spring principle. Thus, the motor 234 drives the
chain 246 continuously, and likewise the sprocket 250 on
the clutch-brake 256 rotates continuously. However, the
primary drive shaft 252 rotates only when the clutch-brake
256 is energized, and then only for one revolution. The
clutch-brake 256 is electrically energized, and once it
receives an electrical signal it imparts precisely one
3~
529
revolution to the primary drive shaft 252. That signal
comes from bag sensor 56 and occurs each time the end of
the sensor arm 54 rises upwardly above the plane of the
platen 28, and into the groove within the head pulley 42
of the upper unit 36 for the bag drive 34. As a con-
sequence, each time a bag neck n passes beyond the sensor
arm 54, the clutch-brake 256 is energized to in turn set
the drive train 238 in motion and thereby effect the
synchronized movements of the chain 150, the ribbon
needle 190, and the twister hook 200, as well as the clamp-
ing bar 70, the bag neck clamp 180 and the ribbon stripper
216.
. In the region between the center plate 12 and the
lower front plate 18, the primary drive shaft 252 carries
a segmented gear 258 (Fig. 14) which rotates adjacent to
and at times meshes with a pinion 260 on the sprocket shaft
162 to which the drive sprocket 158 for the chain 150 is
attached. The teeth of the segmented gear 258 are at the
outset of any tying cycle engaged with the teeth Gf the
pinion 260, and indeed the teeth of the two gears 258 and
260 remain engaged long enough to bring one of the push tabs
168 up to the tying zone z. In other words, when the
clutch 256 engages and connects the primary drive shaft 252
to the motor 234, the primary shaft 252 rotates, and the
segmented gear 258 on it turns the pinion 260, which being
on the sprocket shaft 162, rotates the shaft 162 and sets
the chain 150 in motion. Initially, one of the three
3~1
~o ^
~9gS"9
pusher tabs 168 of the chain 150 is poised along the idler
sprocket 154 just below the feed end of the platen 28
(Fig. 5a). When the segmented gear 258 commences its
rotation, it moves the chain 150 such that the tab 168
which is along the idler sprocket 154 is brought upwardly
over that sprocket and along the track 172, gathering an
awaiting bag neck n as it does. The teeth of the two gears
258 and 260 remain engaged until the tab 168 reaches the
tying zone z and indeed pushes the bag neck n far enough
into the tying zone z to deflect the awaiting ribbon r
(Fig. 5b). At this instant the teeth on the segment gear
258 disengage the teeth of the pinion 260, and the gap in
the row of teeth for the former is presented opposite to
the latter. The segmented gear 258 continues to turn, but
the pinion 260 remains at rest, and likewise so does the
chain 150 and the pusher tabs 168 on it. When the gap
rotates past the pinion 260, the teeth for thç segmented
gear 258 re-engage the teeth on the pinion 260, and the
pinion 260 again rotates. Thus, the segmented gear 258
by disengaging and then re-engaging the pinion 260, imparts
an intermittent motion to the pinion 260 and the shaft
162 which carries it. Preferably the segmented gear 258
has 18 teeth and the pinion 260 has 20, a combination which
causes the pinion 260 to rotate once each time the teeth
of the segmented gear 258 pass by it.
3g
- 1~9~529
During the interval that the pinion 260 is at
rest, the needle 190 brings the ribbon r up behind the
gathered bag neck n and the twister hook 200 twists the
two segments of~the ribbon r together (Figs. 5c, d). Also
the clamping bar 70 shifts and severs the ribbon r at the
shear plate 72, thus freeing the twist tie t which was so
formed. The segmented gear 258 continues to rotate, indeed
all the way to the angular position from which it started,
and as it does it rotates the pinion 260 far enough to
bring the tab 168 on the chain over the idler sprocket 152
at the end of the path p, the tab 168 being just below the
guide rail 32 at this point (Fig. 5a). The subsequent tab
168 comes to a poised position over the idler sprocket 154,
and during the next cycle, that is when the clutch 256 is
again engaged, this tab 168 will move to t}le tying zone z,
pause there while a twist tie t is completed, and then move
on to the idler sprocket 152.
Even though the pinion 260 is disengaged from
the segmented gear 258 during the dwell when the twist tie t
is formed, the pinion 260 and the sprocket shaft 162 on
which it is mounted are nevertheless locked against rotation
so that neither the chain 150 nor the push tab 168 that is
at the tying zone z move during this interval. To achieve
this end, the primary drive shaft 252 adjacent to its seg-
mented year 258 carries an antirotation plate 262 (Figs. 14
& 15) having two convex surfaces 264 and 266 which are
concentric to the axis of the shaft 252, and except for short
30\
- 12~9L52~
transition surfaces 268 between them, occupy the full
periphery of the plate 262. The convex surface 264 has
the lesser diameter of the two and is in the region of the
gear 258 where the teeth are located. The transition sur-
faces 268, on the other hand, lead outwardly from the end-
most teeth, and those suxfaces together with the larger
diameter convex surfaces 266 occupy the region of the gear
258 that lacks teeth. The drive shaft 162 on which the
pinion 260 is located likewise carries an antirotation plate
270~ but the periphery of this plate is defined solely by
a relatively long convex surface 272 and a much shorter con-
cave surface 274. The convex surface 272 is concentric to
the axis of the drive shaft 162 and is just la~ge enough
to barely clear the smaller diameter convex surface 264 on
the antirotation plate 262 for the primary drive shaft 252.
Moreover, the length of the convex surface 272 for the plate
270 equals the length of the lesser diameter convex surface
264 on the plate 262. The concave surface 274, on the other
hand, possesses the same radius as the larger diameter con-
vex surface 266 on the plate 262 and is otherwise positioned
to lie against and conform to the convex surface 266 of
the plate 262 when the gap in the segmented gear 258 is
presented toward the pinion 260.
Thus, while the segmented gear 258 is meshed with
the pinion 260, the small diameter convex surface 264 that
is adjacent to the former revolves close to the convex
surface 272 that is adjacent to the latter. However, when
529
the last tooth on the segmented gear 258 disengages the
pinion 260, the concave surface 274 on the plate 270 that
is adjacent to the pinion 260 passes over one of the
transition surfaces 268 on the plate 262 that is adjacent
to the segmented gear 258 and then lies adjacent to the
larger diameter convex surface 266 on the plate 262. In~eed,
the concave surface 274 on the plate 270 conforms precisely
to the convex surface 266 on the plate 262, and by reason
of this mating of the two plates 262 and 270, the plate
270 and the shaft 162 to which it is affixed cannot rotate,
even though the adjoining plate 262 and the primary drive
shaft 252 on which it is mounted continue to revolve. Both
antirotation plates 262 and 270 are formed ~rom hardened
-steel.
Behind the center plate 12, the primary drive
shaft 252 also carries a cogged pulley 280 (Figs. 3, 4 &
6) around which a timing belt 2~2 passes. This belt extends
upwardly and also :Loops around another cogged pulley 284
(Fig~ 14) carried by a tying head shaft 286 that rotates in
bearings 288 on the center plate 12, the rear p~ate 16
and the upper front plate 20. The outer surface of the
timing belt 282 rides over an idler wheel 290 (Fig. 6~ which
rotates on an adjustable mount 292 that is bolted to the
back face of the center plate 12, and that wheel 290 maintains
the timing belt 282 taut. The two cogged pulleys 280 and
284 are equal in diameter and thus possess an equal number of
cogs, so that each time the clutch 256 is energized to impart
~\
~2~45'~
precisely one revolution to the primary drive shaft 252,
the tying head shaft 286 likewise undergoes precisely
one revolution.
The tying head shaft 286 projects through the
upper front plate 20 of the frame 4, and immediately
~eyond the front face of that plate it is fitted with a
timing wheel 293 ~Fig. 5) which moves past a timing mark
inscribed on the plate 20. Indeed, the wheel 293 is marked
in degrees, and when at rest between tying cycles, 0
is at the timing mark.
Immediately to the rear of the upper front plate
20 for the frame 4, the tying head shaft 286 is fitted
with a segmented gear 294 (Fig. 16) which rotates adjacent
to a pinion 296 on a countershaft 298 that extends between
the upper front plate 20 and the center plate 12, it rotating
in bearings 300 that are on the two plates 12 and 20.
Preferably the segmented gear 294 has 18 teeth and the
pinion has 20 - a combination which causes the pinion 296
and the countershaft 298 which carries it to undergo one
revolution for every full revolution imparted to, the tying
head shaft 286, although the countershaft 298 rotates at a
greater velocity than the tying head shaft 286. Moreover,
the two shafts 286 and 298 are fitted with antirotation plates
302 and 304 which are adjacent to their respective gears
294 and 296. The two gears 294 and 296 together with their
antirotation plates 302 and 304 function similar to the
gears 258 and 260 and the antirotation plates,262 and 270
12~345X9
through which the endless chain 150 and its pusher tabs
168 are advanced. ~y reason of the antirotation plates
302 and 304 the countershaft 298 is locked against rotation
when the teeth of the segmented gear 294 are disengaged
from the pinion 296. This condition exists at the beginning
of any tying cycle, so that when the clutch 256 is energized,
the countershaft 298 does not immediately begin to rotate,
although the tying head shaft 286 does. In~eed, the
pinion 296 does not begin to turn until the ~ap in the
segmented gear 294 passes by the pinion 296 and the first
tooth on the segmented gear 294 engages the pinion 296.
This occurs as the teeth of the other segmented gear 258
run off of its pinion 260 and the antirotation.plates 262
and 270 for those gears lock the sprocket shaft 162 against
rotation, and this of course is when the chain 150 moves
one of its pusher tabs 168 into the tying zone z.
The countershaft 298 projects rearwardly beyond
the center plate 12 where it is fitted with a crank arm
306 (Figs. 6 & 16), and when the countershaft 298 is at
rest, that is when the antirotation plates 302 ~nd 304
prevent its pinion 296 from turning, the crank arm 306
assumes a horizontal orientation (Fig. 6). Moreover, the
countershaft 298 is located directly above the needle
shaft 192 which also projects rearwardly beyond the center
plate 12 where it too is fitted with a crank arm 308.
l'he two crank arms 306 and 308 are tied together with a
connecting link 310, the length of which is such that
~3
~2~4~29
the crank arm 308 likewise assumes a horizontal orientation
when the countershaft 298 is at rest. The needle shaft
192, which likewise forms part of the drive train 238,
carries the ribbon needle 190, and when the two sha~ts 298
and 192 are at rest, the needle 190 is in its retracted
position below guide rail 32 ~Fig. 5a).
~ lowever, once the segmented gear 294 turns far
enough to bring its teeth into engagement with teeth on
the pinion 296, which is when the two antirotation plates
302 and 304 unlock, the segmented gear 294 turns the pinion
296 and the countershaft 298 at twice the velocity of the
tying head shaft 286. The pinion 296 and countershaft 298
undergo precisely one revolution before the two antirotation
plates 302 and 304 again lock up, and during this revolution
the crank arm 306 moves upwardly over top dead center then
downwardly to bottom dead center and then upwardly again
to the starting horizontal position. This full revolution
of the crank arm 306 is transmitted to the needle shaft 192
through the connecting link 310 and crank arm 308 and causes
the needle shaft 192 to move the needle 190 out of its
retracted position to its elevated position and then back
to its retracted position (Figs. 5b, c, d). This movement
of the needle 192, which is generally harmoni'c in character,
takes place while the other set of antirotation plates
262 and 270 lock the sprocket shaft 162 against rotation,
which is while one of the pusher tabs 168 is at the tying
zone z.
-
1."~4~29
The countershaft 298 in turn carries a segmentedgear 312 which rotates adjacent to a pinion 314 on the
twister shaft 210, which along with the bevel gears 206
and 208 and the vertical shaft 202 driven by it, also con-
stitute part of the drive train 238. Like the other sets
of segmented gears and pinions, the segmented gear 312
preferably has 18 teeth and the pinion 314 has 20, sc
that the pinion 314 will rotate one re~olution for every
revolution of the segmented gear 314, but at twice the
velocity. Moreover, the segmented gear 312 and pinion 314
are fitted with antirotation plates 316 and 318 which
prevent the pinion 314 and twister shaft 210 from rotating
when the teeth of the segmented gear 312 are disengaged
from the pinion 314. This condition exists when needle
shaft 192 moves the needle 190 toward its extended position
and also as it moves it away from its extended position
and, of course, while the needle 190 is in its retracted
position.
However, as the needle 190 approaches iis extended
~position (Fig. 5c), the countershaft 298 rotates the seg-
mented gear 312 to the point that the antirotation plates
316 and 318 unlock and the teeth on it engage the teeth of
the pinion 314. The needle 190, by reason of the harmonic
motion imparted to it, dwells somewhat in its extended
position, and during this dwell, the pinion 314 and twister
shaft 210 rotate at twice the speed of the countershaft 298.
The twister shaft 210 in turn rotates the vertical shaft
202 and the twister hook 200 that is on that vertical
shaft 202, and indeed the twister hook 200 turns at four
~5
1,~g~529
times the velocity of the twister shaft 210 due to the
beveled gears 206 and 208 that couple the two shafts 202
and 210. Thus, while the needle 190 moves into its extended
position, dwells there, and commences to move out of it,
the twister hook 200 undergoes four quic~ revolutions,
and during these four revolutions it twists the leading and
trailing segments of ribbon r that are held in the tying
zone z respectively by the ribbon holder 66 and the needle
190 .
Next to its pinion 296, the countershaft 298 is
fitted with another pinion 320 (Fig. 16) which meshes with
a full gear 322 that is fitted to an idler shaft 324
which rotates in bearings 326 that are mounted on the center
plate 12 and the upper front platQ 20. The pinion 320 is
one-half the size of the full gear 322, the former preferably
having 24 teeth and the latter 48. Thus, for every
revolution completed by the countershaft 298, and likewise
by the tying head shaft 286 and the primary drive shaft 252,
the idler shaft 324 undergoes one-half of a revolution.
The idler shaft 324 carries a cam 328 which operates a follower
on the four-way air valve 240 for the cylinder 74 of the
ribbon holder 66. During one-half of a revolution the
cam 328 depresses the follower for the valve 240 and during
the other half allows the follower to extend, each transition
occurring just as the ribbon needle 190 reaches top dead
center which is its fully extended position. The air valve
240 is interposed between a source of compressed air and the
double acting air cylinder 74 for the ribbon holder 66,
1~94S29
and is constructed such that when its follower is de-
pressed, compressed air is directed to one end of the
cylinder 74, and when the follower is extended, compressed
air is directed to the other end of the cylinder 74. Since
the cylinder 74 operates the clamping bar 70, that bar
clamp,s against one jaw 80 o~ the clamping slot 78 (Fig. 8a)
during one-half of a revolution for the idler shaft 324
and against the other jaw 80 of the clamping slot 78
during the other one-half revolution (Fig. 8b), with the
shift from one to the other being when the needle 190 is
in its extended position at top dead center. Thus, the
idler shaft 324 and the cam 328 on it make one-half a
revolution for each full revolution of the pr~ary drive
shaft 252 and cause the clamping bar 70 to clamp the ribbon r
against opposite jaws 80 of the clamping slot 78 during
each succeeding revolution of the primary drive shaft 252.
The angular position of the cam 328 on the shaft 324 is
adjustable to precisely control the time at which the air
cylinder 74 changes the position of the clamping bar 70.
The tying head shaft 286 extends all the way to
rear plate 16 and in the region between the pulley 284 and
the rear plate 16 it carries two cams 332 and 334 ~Figs. 3
~ 4). The cam 332 operates a follower on the four-way air
valve 242 through which compressed air is directed to the
cylinder 186 of the bag neck clamp 180, while the cam 334
operates a follower on the four-way air valve 244 through
which compressed air is directed to the cy~inder 226 of the
~1
~ '.
5~9
ribbon stripper 216. In this regard, the cam 332 is con-
figured to pressurize the cylinder 186 such that it drives
the bag neck clamp 180 up toward the underside of the upper
bag guide 30 ~Fig. 2b), just when the chain 150 stops
moving momentarily as the gap in the segmented gear 258
passes by the pinion 260, which is of course when the chain
150 brings a pusher tab 168 up to the tying zone z. It
is further configured to pressurize the cylinder 186 from
its opposite end when or just before the twister hook 200
stops rotating, and this has the effect of retracting the
bag neck clamp 180 (Fig. 2a). The cam 334, on the other
hand, is configured to pressurize the cylinder 226 such
that it swings the ribbon stripper 216 outwardly and along
the path p beneath the twister hook 200 when the chain 150
commences moving after the dwell, which is just after
the instant the bag neck clamp 180 releases. jAfter the
stripper 216 reaches its forwardmost position, the cam 334
changes the position of the follower for the valve 244 so
that the stripper 216 moves back to its initial pGsition.
The two cams 332 and 334 may be adjusted angularly with
respect to the tying head shaft 286 to control the operation
of the air cylindér 186 which actuates the bag neck clamp
180 and the air cylinder 226 which actuates the ribbon
stripper 216.
The cabinet 6 (Fig. 1) encases the frame 4 and the
drive train 238 that is carried by it. It includes the
side wall 8 on which the spindle 102 for the ribbon reel
100 and tension arm 110 are mounted. It also includes a
~2~S~9
lower front panel 342 which is attached to lower front
plate 1~ of the frame 4 such that it obscures the endless
chain 150. The lower front panel 342 contains a slot 344
through which the ribbon r is threaded to place it over the
needle 190 and the front roller 138. In addition the
cabinet 6 includes an upper front panel 346 which covers
the upper front plate 20 of the frame 4, it being hinged
along its upper margin to the upper front plate 20. The
upper panel 346 generally encloses the ribbon holder 66,
the twister hook 200 and the bevel gears 206 and 208
which drive the twister hook 200. It also obscures the
timing wheel 293.
OPERATION
To prepare the tying machine A for operation, a
reel 100 of ribbon r is placed over the spindle 102, and
a short length of ribbon r is withdrawn from it. This
portion of ribbon r is looped under the tension roller
108 on the arm 110 and over the idler pulley 11~ (Fig. 1).
Beyond the idler pulley 112 it is passed around the corner
roller 136 and thereafter threaded into the slot 344 in
the lower front panel 342. The slot 344 configures the
ribbon r such that it passes beneath the ribbon needle 190,
behind the front roller 13~ and over the roller 196 on the
end o~ the ribbon needle 190 ~Fig. 5a). The ribbon r
is brought upwardly through the path p, looped downwardly,
.
12~34529
and fitted into the clamping slot 78 of the clamping block
68 that forms part of the ribbon holder 66. ~y manipulating
manual controls, the air cylinder 74 for the ribbon holder
66 is energized to move the clamping bar 70 against ribbon r
so that the ribbon r is clamped between the convex rib 90
on one side of the bar 70 and the coxresponding groove 82
along the side of the clamping slot 78. Tracing the ribbon r
backwardly from its free end where it is clamped by the
bar 70, it comes out of the top of block 68 and immediately
loops downwardly to pass obliquely through the path p to
the roller 196 at the end of the ribbon needle 190. Beyond
the needle roller 196 it loops around the front roller 138
and then under the needle 190 to the corner roller 136.
When a bag B containing a product, such as a loaf
of bread, encounters the tying machine A in the proper
orientation, as it would if it were transported past the
machine ~ on the endless belt conveyor C ~Fig. 2), the neck n
of the bag B, while in a somewhat flattened and spread
condition moves onto the platen 28 and enters the path p
in the region of bag drive 34. Indeed, the bag~neck n moves
into the nip formed by the endless belts 46 of the upper and
lower units 36 and 38 of the bag drive 34, so the belts 46
grip the bag neck n and quickly advance it to'the tying zone z,
pulling it laterally into the path p during the advancement.
This causes .he bag B to draw snugly over the product. As
the bag neck n moves between the belts 46, it depresses the
sensor arm 54 for the bag sensor 56, but once the trailing
~0
~4529
edge of the bag neck n passes over the arm 54, the arm 54
rises, causing the bag sensor 56 to produce a signal which
commits the machine A to one tying cycle. Th,e signal causes
the clutch-brake 256 to engage the sprocket 250 with the
primary drive shaft 252 so that the primary drive shaft 2S2
turns through precisely one revolution, whereupon the
clutch-brake 256 locks the primary drive shaft 252 against
further rotation. During this one revolution, a twist tie t
is applied to the bag neck n. Since the timing belt 282
acting through the cogged pulleys 2~0 and 284 connects
the tying head shaft 286 to the primary drive shaft 252 at
a one-to-one ratio, the timing wheel 293, which is on the
end of the tying head shaft 286, likewise rotates through
precisely one revolution, and it may be used to track the
operation of the chain 150, the needle 190, and twister hook
200, the ribbon holder 66, the bag clamp 180, and the ribbon
stripper 216, all of which contribute to placement of a
twist tie t around the bag neck n during the tyiny cycle -
that is, during one revolution of the primary dri-~e shaft 252.
At the commencement of the tying cycle, the timing
mark on the upper front plate 20 is opposite the 0 mark
on the timing wheel 293. In this condition the segmented
year 258 on the primary sl~aft 252 is ~gaged with the pinion
260 on the sprocket shaft 162, and one of the tabs 168 on
the endless chain 150 of the bag pusher 148 is poised over
the idler sprocket 154 immediately below the path p where
it is free to swing backwardly, while another tab 168 is
51
12~4529
located beyond the path p over the sprocket 152, and still
another is located midway between the idler sprocket 156
and the drive sprocket 158 (Fig. 5a). When the primary
drive shaft 252 commences to rotate, the drive sprocket 158
rotates by reason of the engagement of the segmented gear
258 and pinion 260, and the chain 150 brings the poised
pusher tab 168 up over the idler sprocket 154 and onto the
track 172. Indeed, the shoe 176 on the tab 168 rides on
the track 172 while the portion of the chain 150 along which
it is captured between the guide rail 32 and the track 172.
As a result, the chain 150 and track 172 hold the tab 168
in an upright or elevated position, preventing it from
tilting rearwardly. The tab 168 comes behind that bag neck n
which triggered the tying cycle and drives the bag neck n
forwardly, causing it to gather still further behind the
oblique section of ribbon r that extends upwardly through
the path p. Indeed, the tab 168 drives the bag neck n
forwardly to the extent that it deflects the ribbon r.
When the rib 174 of the tab comes to about 3/8 in~hes from
the axis of rotation for the twister hook 200, which is after
about 100 of rotation for the timing wheel 293 (Fig. 5b),
the last tooth on the segmented gear 258 passes off of the
pinion 260 and the antirotation plates 262 and 270 lock
the sprocket shaft 162 against further rotation. In short,
the tab 168 comes to rest in the tying zone z with the bag
neck n gathered between it and the section of ribbon r
that passes between the ribbon holder 66 and the needle 190.
12~529j
~ t the instant the chain 150 stops with its tab
168 in the tying zone z, that is at about 105 on the timing
wheel 293, the cam 332 on the tying head shaft 286 actuates
the air valve 242, causing it to energize the air cylinder
186 such that the cylinder 186 drives the bag neck clamp 180
upwardly to clamp the gathered bag neck n against the
underside of the upper bag guide 30.
At about the same instant, that is at 105~ on the
timing wheel 293, teeth on the segmented gear 294 that is
carried by the tying head shaft 286 engage the pinion 296
on the countershaft 298, causing the countershaft 298 to
rotate. The segmented gear 294 remains engaged with the
pinion 296 for another 180 of rotation of the~timing wheel
~93, and that is long enough to rotate the pinion 296 and
its countershaft 298 through one revolution. During this
revolution the countershaft 298, being coupled to the
needle shaft 192 through the crank arms 306 and 308 and
the connecting link 310, oscillates the needle shaft 192
such that the needle 190 on it moves out of its retracted
position to its extended position (Fig. Sc) and then back
to its retracted position ~Fig. 5d~ in a motion that
approximates simple harmonic. As the needle 190 rises,
its roller 196 carries the ribbon r upwardly behind the
gathered bag neck n so that the ribbon r loops under the
bag neck n and a segment of ribbon r exists ahead of the
gathered bag neck n and another segment exists behind it
(Fig. 5c). The bag neck clamp 180, which holds the gathered
S3
lf~ L529
bag neck n against the underside of the upper bag guide 30,
prevents the looped ribbon r from pulling the bag neck n
upwardly into the twister hook 200. When the needle 190
reaches top dead center (Fig. 5c), that is its fully extended
position, the feed roller 196 on the needle 190 is over the
clamping block 68 of the ribbon holder 66, and indeed the
trailing segment of ribbon r passes upwardly through the
slot 78 in the block 68. ~s such, the trailing segment is
located to one slde of the clamping bar 70. At this point
in the tying cycle, the timing wheel 293 is at about 195.
As the ribbon needle 190 approaches top dead center,
or more precisely at about 155 on the timing wheel 293,
the first tooth on the segmented gear 312 that is carried
by the countershaft 298 comes into engagement with the
pinion 314 that is on the twister shaft 210, and the seg-
mented gear 312 and pinion 314 remain engaged long enouyh
for the former to impart one full revolution to the latter
and to the twister shaft 210. By reason of the bevel gears
206 and 208, this single revolution translates into four
full revolutions for thevertical shaft 202 and the twister
hook 200 which it carries. During these revolutions,
the twister hook 200 gathers the leading and trailing segments
of the looped ribbon r and twists them together. The teeth
of the segmented gear 312 run off of the pinion 314 as the
needle 190 moves back to its retracted position, or more
precisely when the timing wheel reaches about 275, and
at this time the antirotation plates 316 and 318 mate so as
to lock the twister shaft 210 and the twister hook 200, as
well, against further rotation. ..
5~
12~L~S29
Just as the needle 190 is at top dead center,
which is when the timing wheel 293 is at about 195,
the idler shaft 324 carries its cam 328 to a position
where it changes the air valve 240, causing that valve to
admit air to the cylinder 74 of the ribbon holder 66 and
thereby shift the clamping bar 70. The tapered end of the
bar 70 moves through the clamping slot 78 and shears the
trailing segment of the ribbon r as its lower edge crosses
the cutting edge 9~ of the shear plate 72, thus freeing
the completed tie t and of course the bag neck n around
which it is located. At about the same instant the rib 90
on that side of the clamping bar 70 which is presented
toward the trailing segment of ribbon r drives the new end of
the ribbon r into the facing concave groove 82 along the
jaw 80 toward which the bar 70 moves so that the ribbon
holder 66 grips the new end of the ribbon r.
During the final revolution of the twister hook
200, which ends at about 275 on the timing wheel 293,
the cam 332 on the tying head shaft 286 again operates the air
valve 242, and with this actuation the air cylinder 186
to which the valve 242 is connected, moves the bag neck
clamp 180 to its retracted position below the path p.
When the timing wheel 293 reaches about 285,
the ribbon needle 190 is back in its home or retracted
position, that return being marked by the disengagement of
the segmented gear 294 for the tying head shaft 286 from
the pinion 296 and by the mating of the antirotation plates 316
lZ~4529
and 318 which prevent the needle shaft 192 from turning.
At this instant, the leading teeth on the segmented gear
258 that is carried by the primary sha~t 252 again engage
the pinion 260 of the sprocket shaft 162 to rotate the
drive sprocket 158. The chain 150 and the tabs 168 carried
by it again move, and that tab 168 which is at the tying
zone z drives the gathered and tied bag neck n forwardly to
the end of the path p and the guide rail 32 along the
path p. The tab 168 moves over the sprocket 152 far enough
to be below the path p, whereupon the chain 150 stops. This
marks the end of the tying cycle, and the timing wheel is
again at 0.
Returning now to the instant that the pusher tab
168 moved out of the tying zone z, which was at about 255
or the timing wheel 293, the other cam 334 on the tying
about
head shaft 286 at~that instant actuates the air valve 244
such that it admits air to the cylinder 226 for the rib~on
stripper 216 so as to bring the stripper 216 forwardly
simultaneously with the tab 168 on the chain 150. Whereas
the tab 168 clears the gathered and tied bag nec~ n from the
tying zone z, the stripper 216 clears the ends of the twist
tie t from the ribbon holder 66. The cam 334 after about
40 of rotation again actuates the valve 244 to return the
stripper 216 to its retracted or home position.
Once the timing wheel reaches 0, the clutch-
brake 256 disengages the sprocket 250 from the primary
drive shaft 252 and indeed locks the drive shaft 252 so it
S~,
lZ~4529
does not rotate. In this condition, the chain 152 cannot
move because the pinion 260 on the sprocket shaft 162 is
engaged with the segmented gear 258. The needle 190 cannot
move, because the antirotation plates 302 and 304 between
its shaft 192 and the tying head shaft 286 are mated, and
of course the tying head shaft 286 as always is tied to
the primary shaft 252 through the timing belt 282. Similarly,
the twister hook 200 will not turn because the antirotation
plates 316 and 318 between its twister shaft 210 and the
countershaft 298 are mated.
The next tying cycle contains an identical se-
quence of events, except for the fact that a different
pusher tab 168 is used. Indeed, a single pushe~r tab 168
moves through the tying zone z only once every third tying
cycle. Also, the clamping bar 70 during the subsequent
cycle will shift to and clamp along the other jaw 80 of
the clamping slot 78, and to effect this end the idler
shaft 324 which controls the operation of the cylinder 74
for the bar 70 rotates precisely one-half a revolution ~or
every full revolution of the primary drive shaft 252.
This invention is intended to cover all changes
and modifications of the e~ample of the invention herein
chosen for purposes of the disclosure which do not con-
stitute departures from the spirit and scope of the invention.
:
lZ~ 5~9
..
~avid S. Knudsen
~CHINE FOR APPLYING TWIST-TYPE TIES
A tying machine &2. concave groove
B bags 84. cavity
C conveyor 86. pivot pin
p path . . 88.
z tying zone 90. convex rib
t twist-type ties 92. cutout
n bag neck 94. cutting edges
r ribbon
2. pedestal 100. reel
4. frame 102. spindle
6. cabinet 104. ~earing block
8. side walls 106. brake pulley
10. lower frame members 108. tension roller
12. center plate 110. tension arm
14. upper frame mernbers 112. idler roller
16. rear plate - 114. shaft
18. lower front plate 116. bra~e arm
20. upper front plate 118. adjustable link
22. spacer bar 120. elongated slide
24. spacer bar 122. slots
26. spacer bar 124. pins
28. platen 126. slot
30. upper bag guide 128. connecting pin
32. guide rail 130. brake belt
34. bag drive 132. control arm
36. upper unit 134. air cylinder
38. lower unit 136. corner roller
40. carrier plàte 138. front roller
42. head pulley 140.
44. tail pulley
46. belts
48. gear rnotor 4q ~
50. pivot link ~ ~ 148. bag pusher
52. block 150. ndless chain
54. sensor arm 152. sprocket
56. bag sensor 154. sprocket
58. housing 156. sprocket
60. shaft 158. drive sprocket
62.
64. 162. sprocket shaft
66. ribbon holder 164. bearings
68. clamping block 166. squared off link
7 Q clamping bar 168. tabs
72. shear plate 170. pins
74. air cylinder 172. track
76. cavity 174. rib
78. clamping slot 176. shoe
80. jaw
~58~
