Note: Descriptions are shown in the official language in which they were submitted.
14~4'~ 9
BACKGROUND OF THE INVENTION
The field of the present invention concerns gluing machines for
applying an adhesive coating to a flat web or sheet of paper or cardboard.
More specifically, the present invention concerns a gluing machine which can
be readily converted to handle either thin and flexible paper sheets such as
are used in box wrapping machines, or thick and relatively inflexible card-
board such as may be used in forming a laminated game board, or the like, and
sheets having any flexibility within this rang0.
One type of prior art gluing machine is disclosed in the Andresen
et al United States Patent 3,252,701, issued on May 24, 1966. Sheets of
paper are sequentially fed laterally off a stack and progress upward past a
: glue roll. Above the glue roll, an air blast redirects the sheet back over a
. . ~ . . .
vacuum belt conveyor which overlies the supply stack. Thus, the sheets leave
; the magazine in one direction, and follow a recurve path onto the vacuum belt. ~ :
. For obvious reasons, this path dictates that the sheets must be very flexible, ~-
and that stiff, relatively inflexible sheets cannot be used.
SUMMARY OF THE INVENTION
According to the present invention there is provided in a gluing
machine of the type including a magazine for supporting an uprightstack of s~ts
a vacuum head for removing the uppermost sheet from the magazine and displac- -
ing it from the stack to a sheet delivery position, feed rolls for gripping
and transporting the displaced sheet, a glue roll in rolling contact with said . ;
sheet for depositing a film of adhesive thereon, and a conveyor for transport-
ing the coated sheet to a downstream station, the improvement comprising: a.
means mounting said feed rolls, said glue roll and said conveyor to provide a
substantially linear, substantially horizontal path for each sheet during -~
movement from said magazine to said vacuum conveyor; said glue roller being :-
mounted over the path of said sheet; b. a pair of presser rollers mounted
under said glue roll with their respective turning axes parallel to and sub-
stantially equally spaced from the axis of said glue roll; and c. means for
- 1 - :,
.
1~!4~ 9
adjusting said presserrOll5 toward or away from said glue roll, the confront-
ing surfaces of said glue roll and said presser rolls in raised position con-
tinuously arcuately bending the moving sheet to the approximate radius of said
glue roll.
Thus~ bya physical arrangement of operating components, as well as
particular structural details, substantially straight line movement of the
workpiece is made feasible. This capability allows the gluing machine to
handle either very flexible sheets> or sheets which are relatively inflexible,
or any sheets of intermediate flexibility. Certain easily interchangeable and
removable parts may be employed to convert the gluing machine for optimum per-
formance accordingto:~eflexibility of the sheets, thus allowing the one machine
` to have a broad range of usefulness. For example, the gluing machine can be
; used in laminating operations such as in the construction of game boards em-
ploying one or more thick and/or inflexible substrates. At the other extreme
of operating conditions, thin, flexible wrappers for paperboard boxes, or a
- cover sheet for a game board can be effectively handled by the machine after a
simple and quick changeover.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary embodi-
ment of the present invention:
Figure 1 is a schematic side elevation of a gluing machine, partlybroken away to show the upper portion thereof in longitudinal section.
Figure 2 is an enlarged schematic perspective of a stack magazine,
the general area of which is indicated by the arrow 2 on Figure 1.
Figure 3 is an enlarged schematic section of the general area of the
gluing machine indicated by the arrow 3 on Figure 1.
Figure 4 is an enlarged schematic perspective of the major drive and
operating components of the gluing machine.
Figure 5 is an enlarged schematic elevation of the central portion of
- 30 Figure 1
Figure 6 is a fragmentary schematic section
.
1~4~1~49
illus.ratin~ conversion parts used witl~ the upper portion
of the Figure 3 apparatus for handling thin, flexible
sheets.
~igures 7-9 are schematic, fragmenta~y sections
illustrating successive operational positions of the sheet
feeding mechanism shown in Figure 2.
DESCRIPTION OF ~E PREFERRED E~ BOD.IME~T
The gluing machine 10 lFigure 1) includes leg
;~ supports 12 or a stacX magazine 14. The magazine 14
includes an elevator table 16 which is automatically
movable to position the uppermost sheet S of a stack
(indicated by phantom outline 18) of sheets in horizontal
alignment with a sheet feeding mechanism 20. The sheet
feeding mechanism is disposed between side plates 22 and
24, and is driven by a motor Ml to feed one sheet at a
tLme bet~een superposed feed rolls at 26. I~ will be - -
understccd that a clutcih is u~ually interposed between
the motor Ml and the parts driven thereby, but tha~ in the - ;
schematic nature of the present drawings no clutch is
illustrated.
- From the feed rolls, the sheet progresses under ~-A a driven glue roll ~ and onto the ùpper reach of an ele-
vationally ad~ustable vacuum belt conveyor 30 which over-
_ lies a vacuum box 32 and delivers the glue covered sheet
to a further do-mstream processing station. For handling
relatively thick, inflexible sheets, a presser assembly 34
b~neath the glue roll 28 bend~ thc sheet to attain a rela-
tively large contact area bet~een the shee' and glue roll,
whereas for thin sheets, the presser assembly is modified
by re.moving and replacinc~ certain parts. One teaturc of
_3_
. . .
.
- 104~49
tlle p~e~ent invcntion i5 that the shects have subs~antially
straight-line motion after pickup from the stack maga~ine
14 to the vacuum belt conveyor 30 so that oniy minimal
bcnding of the sheet is necessary, during its transport,
S as contrasted with gluing machines of the type ~.~herc the
sheet is recurved during the gluing operation, or is other-
wise bent to a degree which will damage inflexible sheets.
- Other features are that the presser assembly 34 and the
sheet feeding mechanism 20 are readily converted for opti-
mum performance with comparatively thick and thin sheets
having a wide range of flexibility, and that the size range
of the sheets that may be handled is unusually large.
; With reference to ~igure 2 and the stack magazine
14, the elevator table 16 is secured to a rectangular frame-
work 36 that is supported at each corner by the ver.ical
runs of conveyor chains 37, 38, 39 and 40 to elevate or
lower ~he table 16 and maintain it level.. ~nS~r~er~s
only the chains 37 and 39 at one side of the gluing
machine, the arrangement of which is typical for the other
chains, the chain 39 has a.free end carrying a counter-
weight 4I and passes over a driven sprocket 4~; the chain
39 is also provided with a counterweight 41 and is trained
over a fixed idler sprocket 44 adjacent i.s point of
attachment to the framework 36.
The driven sprockets 42 are mounted on the output
shaft 46 of a gear box 48 that is powered by a reversible
motor M2. Chains 38 and 40 are similarly mounted on driven
sprockets 50, the latter chain bcing trained over an idler
sprocket 52. Thus, powered rotat.ion of the shaft 46 in
one direction simultaneously rais~s each corner of the
-4-
1t~4'~49
table 16 from a possiblc lowermost position near ground
level. Assuming that a stack of sheets is on the table 16,
and the upper sheet has been removed by the shcet feediny
~nechanisrn 20 (Figure 1), ~s later described in detail, .he
stack is elevated to place the next sheet in feeding
position by means including a stack-heigh~ sensor rod 54.
The sensor rod 54 is carried by arms 56 which
are fixed to a control rod 58. A lever 60 on one end of
the control rod 58 is connected by a link 62 to a trip arm
64 that is pivotally mounted on a stub shaft 66. In a
manner later described, the free end of the trip arm 64
is pivoted upward each time the sheet feeding mechanism 2Q
(Figure 1) picks up a sheet from the 5 tack and feeds it
toward the glue roll 28. -Thon, the trip arm 64 is allowed
to pivot do-~m~ard, when the sheet feeding mechanism
returns toward the magazine. This causes ~he leve_ 50 t_ ~ -
actuate a microswitch 68 which energizes the motor M2 to
elevate the stack, and also lowers the stack sensor rod -
54 to be lifted by the uppermost sheet of the rising stack
of sheets on the table 16. Accordingly, the actuator of
the microswitch 68 is released when the uppermost sheet is - -
in feeding position, and the motor M2 is de~energized.
As shown in Figure 3, a vertical, transvers~ wall
70 extends batreen the side plates 22 and 24 (Figure 1)
and defines the downstream end of the stack magazine 14.
The upper end of the wall 70 is provided with vertical
grooves 71 that are each aligned with an air port 73 in
an air conduit 75. The ports 73 issue air blasts to
riffle the sheets in the magazine each time a sheet is
remov0d, and thus aid in separatin~ the ~op sheet from
'
,~ .
,
, . , ~
. ..
....
~4Q849
the stack. ~le side platcs each have an L-shaped aperture
72 (Figures 3 and S) for the operating clearance of the
mechanism for driving a vacuum head 74, later described,
that grips the top sheet for removal from the maga~ine.
S For the present it is sufficient to note that the vacuum
head 74 has an L-shaped path of movement corresponding to
the side plate apertures 72, and that the vacuum head is
carried by an upstanding pivot lever 76 (Figures 3 and 4)
and a coxresponding laterally aligned ~ivot lever 78 at
the other side of the gluing machine, both levers being
outside the side plates 22 and 24.
Returning to a general outline of the Figure 3
mechanism, the vacuum head 74 is illustrated in its far-
. thest downstream delivery position for handling relatively
thick, inflexible sheets such as cardboard, and the path of
` a sheet from the magazine 14 to the vacuum conveyor 30approximates the dotted line P. Thus, and as later
described, the vacuum head 74 initially extends across one
edge of the upper sheet in the magazine; and delivers the
20. sheet over a ramp 80 and be~Jeen upper and lower feed rolls
- .. 82 and 84. Both feed rolls are provided with circumfer-
ential grooves, as best sho~n in Figure 4 for the upper roll
82, that allow individual vacuum cup units 85 to operat~
close to the line of gripping contact between the feed
. 25 rolls, and also provide clearance, under certain opera~ing .
conditions, for allowing the vacuum cup units to swing up-
wardly away from a position proximate the feed rolls.
- ~n order to assure easy entry o* the sheets
~etwe~n the feed rolls, the upper (idl.er) roil 82 is
raised from thc lo~er (driv~n) roll ~4 until the ~d~e or
. -6- ;
,. :
,
~ 1~4'~)~49
the sheet is in posit:ion to be grippecl by che feed rolls,
at wnich time the uppcr roll is lowered into contact ~Ji'h
the sheet while the vacuum head 74 returns to~r~ard the m~ga-
: . -
: zine to pick up the next sheet The leading edge of thc
sheet progresses under the glue roll 28 and over two
parallel presser rolls 86 and 88 of the presser assembly
34. The ends of the presser rolls are removably mounted
in upstanding yokes 90 (Figures 3 and 4) that may be ver-
tically adjustcd to regulate the clearance bett~een the
glue roll and presser rolis.
Glue is delivered from overhead conduits, not
shown, into a trough 92 formed by a glue spreader roll 94 ;~
and the glue roll 28, and by a fixed upright wall 96
(only one wall being shown) at each end of said rolls
15. m e walls 96 have arcuate lo~er edges, not visible, which :~
extend into grooved portions of the rolls, and a handle
.
; 98 is provided for adjusting the spreader roll relative ~ ~-
to the glue roll. On the downstream side of the glue roll
28, a series of stripper fingers 100 depending from a
. 20 support rod 101 assure that the sheets are directed toward. . the vacuum belt conveyor and do not wrap around ~he glue
roll. - ~.
Other parts a.~pearins in Figure 3 that should
~e mentioned for ease of recognition in ~he next described
Figure 4 are: a main input shaft 102 is driven by a belt
and pulley drive train 104 from the motor Ml (Figure 1).
Above the input shaft 102 is an Oscillating torque or
ætabilizer shaft 106 which serves ~o transfer driving mo-
tion for the vacuum head 7a from one side to the other
æide of the mzchine. ~ cam shaft 10~ carxies a series of
,, .
. 7
,' ',
'' ,' ,' '''', " '' ' '~' ' ,'"''~ '', ,' '' ;, ' ~ '
1~4~4'3
cams, onc cam ].10 provicling up and down motion fox the
vacuum head 7~. A ~riction brake including a drum 112 on
the cam shaft 108, and a friction band 114 trained over
the drum, serves to inhibit rotation of the cam shaf~ to
S prevent overt-avel of corn~oncnts which are driven t'nere~y.
Adjacent the cam shaft 108 is a roeXing pivot shaft 116
having a eam follower 118 riding on the eam 110, and hav-
ing a crank arm 120 pivotally eonneeted by a shaft 121 to
the pivot lever 76 whieh earries one cnd of th~ vacuum
head 74. The pivot lever 78 (Figure 4~ for the other end
of the vaeuum head is connected by a shaft 122 to a simi-
lar erank arm 123 on the pivot shaft 116.
Figure 4 illustrates the major drive and opera-
ting eomponents of the gluing maehine 10. Beginning with
~5 the main drive input shaft 102, a gear train 124 inter-
eonneets the shaft 102 and the eam shaft 108. For provid-
ing fore and at roeking movement of the vacuum head 74,
an L-shaped eranX arm 126 adjaeent the pivot lever 78 is
pivotally mounted on the pivo~ shaft 116. A eam follower
roller 128 on the lower end of erank arm 126 rides on a
. eam 130 affLxed to the eam shaft 108, and a roller 132
on the upper end portion of the erank arm is aligned with
the pivot lever 78 that earries one end o.~ the vaeu~m head
74. An anehored tension spring 134 biases the lever 78 to
.. 25 maintain the roller 132 engaged with the lever 78, thereby
urging the follower roller 128 against the cam 130. A
sLmilarly funetioning sprin~ 135 biases the lever 76.
. Only one eam is provided to swing the vaeuum
head 74 fore and aft. Thus, the previously mentioned
torque shaft 106 is eonneeted to th~ pivot lever 78 by an
-8~
" ,,
` ~4~849
arm 136 and a link 138, and the othcr cnd of the shaft 106
is coupled by an arm 1~0 and link 142 to the o~her pivot-
able support lever 76 for the other end of the v2cuum head
74. This ecluali~es the motion of the levers 76 and 78
S to prevent tlle vacuum head 74 from skewing and misaligning
the sheet.
It will be noted that the crank arms 123 and
120 are each formed of two levers, the former to acco~o-
date the hub of the L-shaped crank arm 126, and .he latter
to provide access to the shaft 121 by the free end of the
; trip arm 64. Thus, when the vacu~m head 74 is s~ung for-
ward and rearward, the trip arm 64 is pivoted u~ward and
do~mward. This motion, it will bP recalled, cyclically
operates the microswitch 68 (Figure 2) to incrementally
raise the stacX of sheets on the magazine table 16 and
place the uppermost sheet in delivery position after each
time a sheet is removed.
Returning to Figure 4, a feed roll cam 144 is
mounted on the cam shaft 108 ~or raising and lowering the
upper .eed roll 82 (Figure 3) each time a sheet is fed
thereto by the vacuum head 74. m us, the cam l4a raises
and lowers a follower arm 146 that is pivotally moun.ed
on the pivot shaft 116 ancl is coupled to a lever 1a,8.
The lever 148, in turn, is pivotally connected to a crank
150 on a rockshaft 152. Tne rockshaft carries two arms
lS4, each of which by a link 156 is coupled to the central
portion of a bar 158. One ena of each bar 158 is mounted
- on a fix.ed pivot shaft 160, ana the other end OL each bar
supports the upper feed roll 82. With this arrangement,
and ~he timing employed, the icller feed roll 82 (Pigure 3)
' ,.9_
,. , . _ ~.
is elevated from the driven fecd roll ~ to permi.t eas~
entry of the leading edge of a sheet deli.vered by the
vacuum head 7~, and then lowers to grip the sheet against
the driven roll in order to drive ~he shee~ past the glue
roll 28.
The vacuum head 74 is connected to the pivot
levers 76 and 78 by coaxial, rotatable stub shafts 166 and
168, respectively, which extend through the apertures 72
(Figures 3 and 5) in the side plates 22 and 24. Upwardly
directed and aligned arms 170 (Figure 4) and 1i2 on the
stub shafts are fixed to a vacuum tube 174 having closed
ends and a vacuum connector 176 near one end. Mounted
along the tube and communicating wi~h the vacuum tube is a
spaced series of the previously mentioned vacuum cup units
BS, each having a depending suction cup 178 fox gripping
. engagement with a sheet.
. The vacuum head 74 is selectively rotatable
: - a~out the axes of the stub shafts 166 and 168 wnile the
vacuum head i5 moving fore and aft. To effect such rota-
tion, the support shaft 166 is connected to a lever 180
which is pivoted to the piston rod of an air cylinder 182.
The base of the cylinder .is mounted to a bracket 184
(best sho-~m in Figure 7) which is welded to the pivot
levex 76. In this way, projecting movement of the piston
rod directly rotates the vacuum head support shaft 166 -~
(and indirectly rotates the other shaft 168) to swing the
arms 170 and 172, thereby swinging the vacuum cup units
85 clockwise as viewed in Fi~ure 3. A retracting spring 186
on a lever 188 fixed to the support sha~t 168 and con-
nected to the pivot lever 78 biases the vacuum cup units
-10-
., :
, ' ': .
1~4'~ 9
85 ~when the air cylinder 182 is deenergi~ed) to a position
where the lowcr margin of each suction cup 178 (Fi~ure 3)
is substantially horizon.al when the vacuum head 74 is in
sheet delivery position relative to the feed rolls 82 and
84. Rotative movem2nt of the vacuum head 74 is used when
the sheets to be glued are relatively flexible, as des-
cribed in connection with Figures 7-9.
It was previously mentioned that the presser
rolls 86 and 88 (Figures 3 and 4) are vertically adjustable
relative to the glue roll 28. As shown in Figure 4, each
of the presser roll support yokes 90 is provided wit'n upper
parallelogram links 192 secured to a cross shaft 194 for
coextensive movement of said links, and with lower para-
llelogram links 200 mounted on pivot studs 201. One upper
link 192 has a bifurcated bracket 202 secured thereto, and
a rod 204 is threaded through a nut 206 pivoted in the
bracket. An unthreaded portion of the rod, adjacent a
handwheel 208, extends ~hrough and is axially anchored in
a fixed boss 270. Rotation of the handwheel 208, accord-
ingly, simultaneously raises or lowers the presser rolls
86 and 88 wi~h substantially vertical movement, and
allows the running clearance relative to the glue roll 28
to be adjusted with or without the gluing machine in opera-
tion. It will ke recalled that the presser rolls are
used ~hen running relatively inflexible sheets to assure
close contact of the shsets with the glue roll.
In those instances ~ere flexible sheets are
being run, box wrappers for example, the presser rolls 86
and 88 are removcd frorn the yokes 90, as sho.m in Figure 6.
In place of the upstream pressel- roll 8~, a bridge or
.
1~ 49
ramp 212 is mounted across the two yok~s 90. Due to th~
flexibility of the sheets and the delivery path of the
sheets over the ramp 212, the sheets establish a close
wrap under the lower sector of the glue roll 28 without
requiring presser rolls.
Figures 7-9 show successive operational positions
for running flexible sheets S Under these conditions,
the vacuum head 74 is rotated durin~ the delivery of eacn
sheet to the feed rolls 82 and 84, so that the lead.ing
10 edge portion o~ the sheet is flexed upward to clear the
ramp 80. Because thè sheet can be thus flexed, the suc-
- tion cups 178 will maintain flat engagement with the
sheets, even though the vacuum head is rotated. On the
other hand, it is readily apparent that a relatively
inflexible sheet (especially of short dimensions longi-
... . . tudinally of the machine? is liable to break away from the
vacuum cups if the vacuum head is ro.tated because the
sheet cannot bend. Therefore, in the latter case, the air
cylinder 182 is rendered inactive by opening a bleed
20 outlet, not shown, to keep the piston rod of the air
cylinder in its retracted position, and to keep the :
angular relation of the vacuum head 74 to the pivot lever .
76 (and lever 78 Figure 4) substantially as illustrated in .
Figure 7.
It will be recognized that there is no exact line
of demarcation between a so called flexible sheet and an
. inflexible sheet. For this reason, the vacuum c~ps 178
- are pre~erably provided with rubber hoods (not sllown)
which may be manually placed on the cups 178 so that the .....
hoo~s will flex and accommod.ate small differences of
-12-
'. ' ' ' ' . ,,",' '~ ' . , :
lQ~ 49
planarity bet-JceJl the suction CllpS and sheets which are
somewhat in~lexible, but bend sufficien~ly for a ~e~d.iny
operation without rotation of the vacuum head 74 as des-
cri~ed. Thus, it is preferred that the sheet-contacting
surfaces of the vacuum cups 178 are rigid for handlin~
:~ paper, and that flexible accesso~y hoods as described
. be provided for handling cardboard, because this in addi-
tion to the other provisions described, provides optimum
handling efficiency throughout the ~lexibil.ity range
of the sheets.
. Again re~erring to Figure 7, a sheet ~eeding -.
operation begins with the vacuum head 74 in its rearmost
and lowermost position, as respectively effected by the
: cams 130 and 110 (Figure 4).~ This places the vacuum
cups 178 in gripping contact with the leading edge portion
of the uppermost flexible sheet S. At this time, the air
conduit 75 directs high velocity air blasts from the mul-
.tiple air ports 73 into the a~jacent edge of the stack of
: sheets to aid in stripping the top sheet from ~he stack. :-
- 20 Before the vacuum head is moved upward from the Figure 7
position, the air cylinder 182 is energized to swing the
vacuum cup units 85 upward and rearward, thus flexing the
- leading edge portion of the top sheet S into a gradual bend .~:
and into general parallelism with the ramp 80 as shoT.~n in
Fi~ure 8. The cam 110, meanl`nile, is rotating to advance
its highest profile past the cam follower roller 118.
Accord.in~ly, an intermediate rotational position ol ~he
cam 110, which position occurs ~e~ween the operational
sta~cs snown .in Figures 8 and 9, swings the cranX arm 120
about the axis ol the pivot sha~t 116 to elevate the pivot
-13-
- lQ4~)849
lever 76 (and the countarpart pivot lcver 78, Figure 4) to
raise the vaouum head 74 for forward movement at the appro- .
ximate elevation sho-~n in Figure 9.
~hen the vacuum head is su~ficiently raised for
S fonlard movement, the lowest profile of the cam 130 ~Figure
4) moves under ~he follower roller 128, thus allowing the
tension springs 134 and 135 to urge the pivot levers 76 and
78 fon~ard, carrying the vacuum heaa 74 forward, carrying ,
the vacuum head 74 toward the feed rolls 82 and 84. Coex-
10 tensive and coincidental movement of the ends of the vacuumhead 74 is achieved by means of the stabilizer or torque
shaft 106 which, by means of the arms 136 and 140, and
. links 138 and 142, ties the pivot levers 76 and 78
together for unitary movement. While the vacuum head is ":
being thus moved, the upper feed xoll 82 (Figure 9) is
raised from the lower feed roll 84 to assure a wide entry ~''
, throat for the sheet. Thus, the cam 144 (Figure 4) with
its associated follower 146 and lever 148, rotates the ;~
' ',, shaft 152 whereby the arms 154 and links 156 pivot the --
carrier bars 158 for the eed roll 82 u~ward, and th2 com-
ponents descri~ed attain the Figure 9 position with the . .:
sheet S released by the vacuum head and ready io be gripped
by the feed rolls.
me cam 144 (Figure 4) then lowers ths,upper feed, ,,: .
: - 25 roll 82 so that the gripped sheet S progresses fonJard
under,the glue roll 28, and the vacuum head 74 follows a ~ -
generally reverse path of movement (rearward and downward)
while it is erected to th~ Figure 7 position ready for ' -
qripping and transporting the next top sheet from the
, 30 stack magazine.
-14-
, ' ,. , ~
49
~ 1~ f~edin~ o~era~ion wh~n handlin~ cardboard or
other relatively inflexible sheets is reviewed in brie~
outline in conjunction with Figure 3. The bridge 80
(Figur~s 7-9) is removed and the presser rolls 86 and 88` - 5 are mounted in the yokes 90 (Figures 3 and 4). Air cylin-
der l82 is adjusted so that it will not operate, and the
vacuum head 74 will therefore, as previously mentioned,
.. ..
move up and down, and fore and aft while maintaining the
l approximate orientation shown in Figure 3. Thus, the sheet
J 10 pic~up position of the vacuum head 74 is as shown in
i Figure 7 for the flexible sheets, and the vacuum head
moves upward in the side plate slots 72 ~Figure 3) and
forward toward the feed rolls.
Due to the inflexibility of the sheet ~not shotm)
: 15 gripped and elevated by the vacuum cups 178, the edge pro-
file of the sheet will assume the contour of the previously
mentioned approximate delivery path P. In o~her words, -~
~he sheet will initially bend upward from its upstream
edge portion within the magazine when the downstream edge -
is raised by the vacuum cups 178 with the separation of
~¦ ~ the sheet from the stack aided by the air jets from the
ports 73. ~ccordingly, the path P over the stack will vary
¦ solhè~h~t according to the flexibili~y and leng~h of the
sheets longitudinally of ~he machine, and short sheets will
¦ 25 tend to break away from the vacuum cups 178 unless the
previousl~ mentioned flexible rubber hoods (not shown) are
placed thereon so that the suction cups conform to th~
plane of the sheet.
The feed rolls 82 and 84 open to receive the
3~ ghect, in the same manner mentioned in connection with
-15-
- -- ~
104~)849
Figure 9, and th~n close ~o advance the shec~ ~hilc ~he
vacuum head 7~ returns to the Figure 7 po.sition. The
- moving sheet contacts the driven glue roll 28 and passes
there~nder ~hile being pinchcd between the presser rolls
- 5 82 and 84 to provide continuous running ~lexure of the
. sheet into contact with the glue roll. Depending upon the
specific flexibility of the sheets bein~ handled, the
sheet may then bend slightly upward over the elevationally
:` adjustable vacu~m belt conveyor 30, or for very stiff
sheets the conveyor 30 may be lowered belo~.~ the position
shown in ~igure 3. In either event, the sheets are glued
and transported.in substantially planar co~dition.
Fxom the preceding detailed description, it is
believed evident that the gluing machine 10 o~ the present
invention is capable of handling sheets within a wide
- range of flexibility and/or thickness, and requires only
minimum labor and parts to accommodate ~hat range.
Although the best mode contem~lated for carrying
out the present invention has been herein s~o~m and
described, it will be apparent that modification and vari-
ation may be made without departing from what is regarded ::
to be the subject matter of the invention. . .~ .
RBC:csa
'~
; -16-
,, ' ~'.
.. .~,
