Note: Descriptions are shown in the official language in which they were submitted.
CA 02325083 2000-11-03
This invention relates to a tape head for use in a taping machine for sealing
cardboard cartons.
Tape head assemblies of generally the type disclosed herein are described in
a large number of patents, including United States Patent No. 5,184,997,
issued to
R.C. James et al on February 9, 1993, and the patents listed in the James et
al.
document. The heads described in the prior art are designed to apply a strip
of tape
to the leading end, the top seam between the flaps, and the trailing end on a
carton
advancing beneath the head on a conveyor. A second head can be provided to
apply a strip of tape to the bottom and adjacent ends of the carton at the
same time
as tape is being applied to the top thereof.
Existing tape heads are somewhat limited in terms of speed of operation, i.e.
they cannot be operated at high speeds without jamming or damage to the heads.
A
feature common to such tape heads is the use of front and rear presser rollers
which
are mounted on arms, each of which is designed to rotate into the path of
travel of a
carton during a taping operation. If cartons are being fed beneath a tape head
at
high speed and a pair of cartons are too close together, the second carton of
the
pair can pass beneath the front presser roller and ram the rear presser
roller, which
is still in an extended position. Because the arm carrying the rear presser
roller is
not designed to rotate in the direction of movement of the carton. The result
can be
jamming and damage to the taping machine.
The object of the present invention is to provide a solution to the above
defined problem in the form of a relatively simple tape head for use in a
carton
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CA 02325083 2000-11-03
taping machine which permits high speed operation of the machine without the
risk
of jamming or damage to the tape head.
Accordingly, the invention relates to a tape head for applying tape to the
front
and rear ends and one side of a container contiguous with such ends
comprising:
(a) a frame;
(b) a front roller on said frame for receiving tape from a source thereof;
(c) a front roller arm carrying said front roller pivotal on said frame for
rotation between an extended position in which said front roller can engage
the front
end of a carton for applying tape to said front end and to said one side of
said carton
as the carton is moved past said front roller;
(d) a rear roller for pressing the tape against said one side and the rear of
the carton;
(e) a rear roller arm carrying said rear roller pivotal on said frame for
rotation between an extended position in which said rear roller can
successively
engage such one side and said rear end of the carton, and a retracted position
in
said frame;
(f) an actuator roller for engagement by the front end of a carton
downstream of the front roller in the direction of carton travel past the tape
head;
(g) an actuator lever carrying said actuator roller and adapted to move
said rear roller arm to the extended position; and
(h) a link assembly for coupling said front roller arm to said rear roller arm
to move said rear roller arm from the extended to the retracted position if a
carton
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CA 02325083 2008-01-24
engages the front roller while the rear roller is still in an extended
position engaging
the rear end of an already taped carton.
This invention is described hereinafter in greater detail with reference to
the
accompany drawings, which illustrate a preferred embodiment of the invention,
and
wherein:
Figure 1 is a schematic isometric view of a taping machine for sealing
corrugated
cartons;
Figure 2 is a side view of a tape head assembly in accordance with the present
invention;
Figure 3 is an isometric view of the tape head assembly of Fig. 2 with parts
omitted;
Figure 4 is an exploded, isometric view of the tape head assembly of Figs. 2
and
3; and
Figures 5 to 10 are schematic side views of the tape head assembly of Figs. 1
to 4 illustrating a taping operation.
With reference to Fig. 1, the tape head of the present invention is intended
for
use on a machine designed to seal corrugated cardboard cartQns. The machine
includes a main frame I supported at the corners by legs 2. The frame I
carries
horizontal rollers 3 for slidably supporting cartons during taping thereof by
identical
upper and lower tape heads generally indicated at 4 and 5, respectively. Tape
6 is fed
to each of the tape heads 4 and 5 from a source thereof, in this case rolls 7
(one
shown). The upper tape head 4 is mounted on a crossbar 8A extending between
posts
8. The posts 8 are connected to and supported by the sides of the frame 1.
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CA 02325083 2008-01-24
The lower tape head 5 is mounted in an opening in the surface defined by the
rollers 3. Endless, motor driven belt assemblies 9 or similar systems are
disposed on the
sides of the path of travel of the cartons for driving the latter between the
tape heads 4
and 5.
Referring to Figs. 2 to 4, the tape head assembly of the present invention
includes a frame generally indicated at 10 (Fig. 2) for mounting in a taping
apparatus
of the type shown in Fig. 1. While a taping machine normally includes two tape
heads (upper and lower), for the sake of simplicity only an upper tape head is
illustrated in the drawings and described below. The frame 10 is defined by a
main,
generally rectangular side plate 11, which is connected to side plates 12 and
13 by
crossbars 15 (Fig. 4) located generally at the corners and center of the side
plate 11.
A gap 16 between the plates 12 and 13 facilitates threading of one end of a
tape 6
from a source thereof (not shown) into the tape head. The tape enters the
assembly
around an idler roller 18 and a clutch roller 19 rotatably mounted on a block
20. The
clutch roller 19 is rotatable in one direction only. A slot 21 in the plate 11
for
receiving screws (not shown) permits vertical adjustment of the position of
the block
on the plate 11.
A blade 23 is mounted on a bar 24 extending transversely of the frame 10 on
a free end of an arm 25. The arm 25 is mounted on one end of a sleeve 26
(Figs. 3
20 and 4). The sleeve 26 is rotatable on a shaft 27 extending between the side
plates
11 and 12. A helical tension spring 29 extends between a pin 30 on one end of
the
arm 25 and a pin 31 on the plate 11. The spring 29 biases the free end of the
arm
and consequently the biade 23 downwardly beneath the plane of the bottom of
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CA 02325083 2008-01-24
the frame 10. A guide plate 33 of L-shaped cross section is mounted on a block
34
on the blade end of the arm 25. As described hereinafter in greater detail,
the plate
33 determines when a tape cutting operation occurs. A plurality of threaded
holes 35
are provided in the arm 25 and the block 34 for receiving screws (not shown)
permitting adjustment of the position of the guide plate 33 longitudinally on
the arm
25.
A carton 38 (Fig. 5) passing beneath the tape head (from the right in Fig. 2)
first encounters a front roller 39 mounted on a shaft 40 extending outwardly
from the
bottom free end 41 of an arm 42. A top comer of the generally S-shaped arm 42
is
mounted on one end of a sleeve 44, which is rotatable on a shaft 45 extending
between the frame plates 11 and 12. An idler roller 46 (Fig. 3) is mounted on
a
bottom comer of the arm 42. As shown in Fig. 2, in the rest position of the
arm 42,
the roller 46 is accessible through the gap 16 for threading tape 6 from the
clutch
roller 19 around the idler roller 46 to the front roller 39. One end of a link
arm 48
(described hereinafter in greater detail) is pivotally connected to the top
end of the
arm 42 by a pin 49.
After passing the roller 39 and a trailing end 50 of the blade guide 33, the
leading end (in the direction of travel) of a carton 38 encounters an actuator
roller 52
mounted on the bottom free'end of an actuator lever generally indicated at 53.
The
lever 53 is defined by a pair of parallel, spaced apart arms 55 and 56, the
roller 52
being mounted on a shaft 57 extending therebetween. The arms 55 and 56 are
mounted on the ends of a sleeve 59 (Fig. 4), which is rotatable on a shaft 60
extending between the frame side plates 11 and 13. As best shown in Fig. 4,
one
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CA 02325083 2008-01-24
arm 56, of the lever 53 is longer than the other arm 55, i.e. extends upwardly
beyond
the sleeve 59. A spring 62 extending between a pin 63 on the upper end of the
arm
56 and a second pin 64 on the side plate 11 biases the bottom end of the lever
53
and consequently the roller 52 towards the inlet end of the frame 10, i.e.
upstream in
the direction of carton travel.
A shaft 65 extending transversely between the arms 55 and 56 of the lever
pivotally supports a cylindrical front swivel block 66. A rod 67 extends
rearwardiy
from the block 66 through a rear swivel block 69 which is rotatably mounted in
a
clevis-like bracket defined by a pair of arms 70 extending outwardly from a
sleeve
71. The rod 67 carries a pair of compression springs 73 and a spacer ring 74.
Two,
short compression springs 73 are used, because long springs of this type tend
to
become distorted. An adjustment nut 75 (Fig. 3) is mounted on the threaded
rear
end of the rod 67 for maintaining the block 69 on the rod 67. Thus, the
position of
the rear swivel block 69, which is slidable on the rod 67, and consequently
the
compression on the springs'73 can be adjusted by rotating the nut 75 clockwise
or
counterclockwise on the rod 67.
The sleeve 71 forms part of a rear roller arm assembly generally indicated at
77 (Figs. 3 and 4). The sleeve 71 is rotatably mounted on a shaft 78 extending
between the side plates 11 and 13. A rear presser roller 79 is mounted on a
shaft 80
(Fig. 3) extending between the bottom free ends of arms 82 and 83 for pressing
the
trailing end of a strip of tape 6 against the trailing end 85 (Fig. 8) of the
carton 38_
The arm assembly 77 is biased towards and caused to rotate to the use position
by
the compression springs 73'when a carton 38 pushes the actuator lever 53
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CA 02325083 2008-01-24
upwardly and rearwardly. Such movement of the lever 53 compresse$ the springs
73,
pushing against the swivel block 69 to bias the rear roller arm assembly 77
downwardly. Thus, when the trailing end 85 of a car#on 38 passes the roller
79, the
latter foilows the carton 38 to press the trailing end or tab of the tape
against the
trailing end of the carton 38 (Fig. 8).
A triangular lever 88 is also mounted on the shaft 78 close to the side plate
11. A helical extension sprirng 89 extends between a pin 90 on a top comer of
the
lever 88 and a pin 91 (Figs. 5 and 6) on the side plate 11 biasing the bottom
corner
of the lever 88 rearwardly of the frame in the direction of carton travel (to
the left in
Figs. 5 to 10). The rear end 93 of the link arm 48 is pivotally connected to
the bottom
corner of the lever 88 by a short shaft 95 and a flange bearing 96 (Fig. 4). A
nut 97
on the inner free end of the shaft 95 is adapted to fit into a notch 99 in the
trailing
end of the one arm 83 of the rear roller arm assembly 77 to push the latter
forwardly
(Fig. 3) as described hereinafter in greater detail.
OPERATION
In the rest position of the elements of the tape head (Fig. 5), the front
presser
roller 39 and the actuator roller 52 extend out of the casing (upwardly or
downwardly as
the case may be). For the sake of simplicity only the downwardly extending
situation is
described with reference to Figs. 5 to 10.
When a carton 38 being fed in the direction of arrow A encounters the front
roller 39, it pushes the roller 39 upwardly causing the arm 42 to pivot around
the
axis of the shaft 45. The end of the tape 6 on the roller 39 becomes attached
to the
leading end of the carton 38 and as the roller travels up the leading end of
the
carton
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CA 02325083 2008-01-24
38, and then along the top thereof, to the top flaps thereof (Fig. 6). When
the carton
38 passes beneath the guide plate 33, the iatter is pushed upwardly until the
trailing
end 50 thereof reaches the tevel of the roller 39. As the arm 42 rotates, the
link bar
48 is pulled by the arm (to the right in Figs. 5 and 6). In the uppermost
position of
the roller 39, (Fig. 6), the nut 97 on the bar 48 comes to rest in the notch
99 on the
arm 83 of the rear roller arm assembly 77. Con6nued movement of the carton 38
pushes the roller 52 upwardly and rearwardly in the direction of carton travel
to
pivot the lever 53 upwardly. As the lever 53 rotates, the compression springs
73 are
compressed, biasing the sleeve 71 and the rear roller arm assembly 77
downwardly so that it travels along the tap of the carton 38 as the latter
advances.
During movement of the carton 38 beneath the rollers 52 and 79, the tensioned
tape 6 holds the roller 39 in the elevated position. It will be noted that as
the
assembly 77 rotates, the nut 97 on the link bar 48 no longer rests in the
notch 99.
Referring to Fig. 7, as the trailing end of the carton 38 passes the end 50 of
the guide 33, the spring 29 forces the blade 23 rapidly downwardly to sever
the tape
6 between the rollers 39 and 52. The spring 89 retums the arm 42 and the
roller 39
to the extended rest position, in which the roller 39 lies in the path of
travel of the
next carton. Shortly thereafter, the roller 79 passes the trailing end of the
carton 38,
and is biased downwardly and in the direction of carton travel to press the
trailing
end of the tape against the trailing end 85 of the carton.
If the next carton is too close to the already taped carton, i.e. if the rear
roller
arm assembly 77 is still down and the actuating lever 53 is up (Fig. 8) there
is a
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CA 02325083 2000-11-03
distinct possibility that the second carton will strike the arm assembly 77
resulting in
jamming and/or damage to the tape head. This is prevented when the second
carton pushes the roller 39 and consequently the arm 42 to the elevated
position.
Such movement causes the link bar 48 to move with the arm 42. When the nut 97
enters the notch 99 in the arm 83 of the rear roller arm assembly 77, the nut
99
pushes the assembly 77 causing the latter and specifically the roller 79 to
rotate
upwardly out of the path of travel of the second carton (Fig. 9). The carton
38
travels under the rollers 52 and 79. The tape 6 is still severed, but the
trailing end or
flap of the tape is not pressed against the trailing end of the carton.
However, the
important point is that machine damage is avoided. The spring 62 returns the
actuator lever 53 and consequently the remaining elements of the tape head to
the
rest position (Fig. 10).
Assuming that the second carton is not too close to an already taped carton
(which is normally the case), when the trailing end of a carton releases the
roller 52
on the actuator lever 53, the spring 62 returns the lever 53 and consequently
the
rear roller arm assembly 77 to the rest position.
The use of the tape head described above permits safe operation of a taping
machine at speeds substantially higher than heretofore possible.
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