U.S. patent number 3,720,141 [Application Number 05/026,483] was granted by the patent office on 1973-03-13 for apparatus for making thermoplastic handle bags.
This patent grant is currently assigned to FMC Corporation. Invention is credited to David K. Stock.
United States Patent |
3,720,141 |
Stock |
March 13, 1973 |
APPARATUS FOR MAKING THERMOPLASTIC HANDLE BAGS
Abstract
This application discloses a bag machine adapted to form handle
bags from a thermoplastic web material. The handle bags are made
with a reinforced mouth comprising two or more layers of web which
are of sufficient width so that hand receiving cut-outs can be
formed therein. A bat of this form can be securely and easily
grasped by one hand and the multi-layered web provides sufficient
strength to prevent tearing of the bag about the cut-outs.
Inventors: |
Stock; David K. (Green Bay,
WI) |
Assignee: |
FMC Corporation (San Jose,
CA)
|
Family
ID: |
21832093 |
Appl.
No.: |
05/026,483 |
Filed: |
April 8, 1970 |
Current U.S.
Class: |
493/194; 156/515;
383/10; 383/63; 493/35; 493/204; 493/342 |
Current CPC
Class: |
B29C
66/73921 (20130101); B29C 66/005 (20130101); B29C
65/305 (20130101); B29C 66/81427 (20130101); B29C
66/8226 (20130101); B29C 66/83221 (20130101); B29C
65/7461 (20130101); B29C 66/843 (20130101); B29C
65/18 (20130101); B29C 66/8221 (20130101); B29C
66/80 (20130101); B29C 66/431 (20130101); B29C
66/8161 (20130101); B29C 65/749 (20130101); B29C
66/81417 (20130101); Y10T 156/1313 (20150115); B31B
70/642 (20170801); B31B 70/876 (20170801); B29C
66/81422 (20130101); B29L 2031/463 (20130101); B29C
66/1122 (20130101); B29L 2031/7128 (20130101); B29C
2793/0018 (20130101); B31B 70/14 (20170801); B31B
70/64 (20170801) |
Current International
Class: |
B29C
65/18 (20060101); B31B 19/00 (20060101); B29C
65/00 (20060101); B31B 19/86 (20060101); B31B
19/64 (20060101); B29C 65/74 (20060101); B31b
001/14 (); B31b 001/86 (); B32b 031/00 () |
Field of
Search: |
;93/8,33,35H,58P,59MT,36A,93C ;156/515,512,204,250,269 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Juhasz; Andrew R.
Assistant Examiner: Gilden; Leon
Claims
What is claimed is:
1. An apparatus for making handle bags from a thermoplastic web
which is folded along its longitudinal median so that the margins
of the web are even, said apparatus comprising means for folding
each of the web margins to produce a lip having at least two web
layers, and means for simultaneously making aligned cut-outs and a
plurality of line seals in each lip, said seals running
longitudinally of the cut-outs and straddling the cut-outs, and
means for transversely severing and sealing the web to complete the
bag.
2. The apparatus of claim 1 wherein said means for making the
cut-outs and line seals comprises platens reciprocable toward and
away from each other, means directly actuating one of the platens
for reciprocation, and means responsive to the reciprocation of
said one platen for reciprocating the other platen.
3. The apparatus of claim 2 wherein said means for reciprocating
said other platen comprises centrally pivotally mounted rocker
arms, a slidably mounted plunger connected to said one platen, a
slidably mounted plunger connected to said other platen, and means
on said plungers engageable with said rocker arms to cause rocking
of said arms when said plunger of said one platen is reciprocated
which causes concurrent oppositely directed reciprocation of said
plunger of said other platen.
4. An apparatus for simultaneously making hand-receiving cut-outs
and line seals in a web folded along its longitudinal median and
having each of its ends folded to produce a multi-layered band;
said apparatus comprising means for laterally separating and
supporting longitudinal portions of said bands; stationary sealing
and cutting means located between said separating and supporting
means; platens, mounted for reciprocation toward and away from each
other, for firmly pressing the separated bands in contact with said
sealing and cutting means to make reinforcing line seals and the
hand-receiving cut-outs in each of the separated bands.
5. The apparatus of claim 4 wherein said separating means comprises
generally rectangular plates, said plates being mounted for limited
movement toward and away from each other, slots in said plates
providing clearance openings for said sealing and cutting means to
project therethrough, and springs for holding the plates away from
each other, said plates being moved toward each other during
movement of said platens toward said sealing and cutting means to
thereby firmly clamp the folded ends of the web during cutting and
sealing.
6. An apparatus for making handle bags associated with a bag
machine having means for counting the number of bag machine cycles
to produce counted bag stacks and said counting means operative to
interrupt bag machine operation for at least one bag making cycle
at the end of the count; said handle bag making apparatus
comprising opposed platens reciprocable toward each other for
making line seals and cut-outs in the folded edges of a
thermoplastic web; stationary seal bars and a cutting die located
between said platens; means mounting said seal bars and cutting die
for pivotal movement away from the path of the web; and means,
responsive to interruption of bag machine operation for at least
one bag making cycle, for pivoting said seal bars and cutting die
away from the web path.
7. The apparatus according to claim 6 further comprising means for
preventing reciprocable movement of said platens during an
interrupt cycle.
8. The apparatus according to claim 6 further comprising means for
disposing of the cut-out web portion.
9. The apparatus according to claim 7 wherein said means for
preventing reciprocation comprises a fluid operated cylinder.
10. The apparatus according to claim 6 comprising a vacuum system
for removing the cut-out portions of the web as they are
produced.
11. A method for making a thermoplastic handle bag comprising the
steps of folding the ends of a web, which is folded along its
longitudinal median, to produce a band of at least two web layers;
and concurrently forming line seals and hand-receiving cut-outs in
opposed longitudinal portions of the band.
Description
Presently available bag machines for making handle bags of the
nature disclosed herein provide web forming apparatus for making a
multi-layered skirt in each main panel of the bag. The skirt can be
of any desired width determined by the strength required and the
size of the hand-receiving cut-out. To provide increased strength
to the bag skirt, welds, of any desired configuration, are made
attaching the skirts to the underlying bag panel. It is usual
practice to provide an operational sequence where the cut-outs are
made first and then welds are made in the skirt. In providing
distinct apparatus to make the cut-outs and then make the weld
pattern in the skirts, threading of film through the machine is
more difficult and more space is required on the attachment rails
of the bag machine. Further by providing separate apparatus for
making the cut-outs and the welds in the skirt, separate drives
must be provided for each of these apparatus from the main drive of
the bag machine. Mechanically this design is complicated and
accordingly the risk of timing failures and drive failures is
substantially increased.
Handle bag making apparatus is also designed so that the seal bars
for making the seals in the skirts of the bag reciprocate. Since
the seal bars are heated by electrical resistance heaters they are
typically connected to the electrical circuit by flexible
conductors, such as braided wires, to allow reciprocation of the
seal bars and yet maintain an electrical connection to the heater
circuit. It oftentimes happens that the flexible electrical
conductors become fatigued by the continual flexing in response to
the reciprocation of the seal bars. The conductors accordingly
break under these conditions.
According to the present invention the seal bars for making the
welds in the skirt of the handle bag are rigidly mounted thus
avoiding the use of flexible electrical conductors which obviate
the possibility of breakdown as explained above.
It is another feature of the present invention to mount the handle
bag making apparatus so hat it can be displaced away from the path
of the web to an inoperative position when bag machine production
is interrupted for a period of time greater than one machine cycle.
In the absence of such an arrangement the film would be damaged by
the heated seal bars due to the increased time exposure of the film
to the heated seal bars. Further benefits attained by such an
arrangement are that maintenance, such as cleaning of the seal
bars, and replacement of the seal bars is facilitated.
It is usual practice to provide a teflon glass cloth covering for
seal bars to prevent sticking and buildup of web material on the
seal bars. Providing teflon glass cloth requires suitable devices
for holding the cloth to the seal bar structure. Contrary to this
practice this invention provides a coating for the seal bars having
appropriate release properties that prevent sticking and buildup of
web material on the seal bars. By obviating the use of teflon glass
cloth it is possible to operate the seal bars at a lower
temperature, because with use of the teflon glass cloth a
temperature drop of approximately 75.degree. is experienced.
Another feature of this invention is the provision of a unique
drive to the platens which form the seals and the cut-outs in the
skirt of the bag. As mentioned above the usual handle bag making
apparatus is designed with separate mechanisms for forming the
cut-outs and the seal pattern in the bag lip or skirt. Separate
drives are also provided to operate the cut-out dies and the seal
bar structure in unison with the intermittent motion of the web.
Each of the separate mechanisms, viz., cut-out dies and seal bar
structures, perform their functions simultaneously on each of the
opposed lip portions of the bag. To illustrate, the lip portion
associated with each main panel of the bag have the cut-outs formed
by simultaneously operating platens reciprocating toward and away
from each other. The platens carry male dies that cooperate with a
stationary female die located between and equidistant from the male
dies. The drive for each platen includes a cam, a cam follower, a
spring and a cam follower yoke and push rod.
According to the present invention reciprocating motion of the
above described nature of each platen is accomplished by providing
a single cam, a follower, a spring and a cam follower yoke and push
rod. The opposed reciprocating motion to the upper and lower
platens is transmitted by use of a pivoted rocking beam, the
details of which will be explained hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic central longitudinal section of a bag machine
incorporating the handle bag making apparatus of the present
invention.
FIG. 2 is a transverse section of a folded thermoplastic web
showing a single fold lip or skirt.
FIG. 3 is similar to FIG. 2 showing a double fold lip which
provides three web layers.
FIG. 4 is a perspective of a completed handle bag which has the
hand cut-out partially severed.
FIG. 4A shows one manner in which the hand receiving cut-out may be
made so that the partially cut web lip is retained with the
bag.
FIG. 5 shows a perspective of a completed handle bag with the hand
cut-out completely removed.
FIG. 5A shows another manner in which the partially cut web lip can
be retained with the bag.
FIG. 6 is an enlarged transverse section, taken substantially along
the line 6--6 of FIG. 1, with parts broken away.
FIG. 7 is a fragmentary portion of FIG. 6 showing a different
relationship of certain parts of the platen drive.
FIG. 8 is a section of FIG. 6 taken along the line 8--8.
FIG. 9 is a fragmentary portion of FIG. 8 showing a piston, for
interrupting operation of the platens, actuated.
FIG. 10 is an enlarged fragmentary plan of the handle bag making
mechanism taken along the line 10--10 of FIG. 1.
FIG. 11 is a section, taken along the line 11--11, of FIG. 10.
FIG. 12 is a horizontal section, taken along the line 12--12 of
FIG. 11.
FIG. 13 is an enlarged fragmentary portion of FIG. 6 with parts
broken away.
FIG. 14 is an enlarged fragmentary view of the seal bars and
platens taken along line 14--14 of FIG. 11 and showing the
relationship of parts before the platens are reciprocated toward
each other.
FIG. 15 is similar to FIG. 14 showing the operation whereby the
line seals and the cut-out are made.
GENERAL ARRANGEMENT
Referring to FIG. 1 there is shown a bag machine, generally
indicated by the numeral 20, having operatively mounted thereon the
handle bag making apparatus of the present invention. Briefly the
bag machine comprises a base plate 22 supporting a plurality of
upwardly extending transversely aligned side plates 24a, 24b and
24c which provide support for the web handling mechanisms of the
bag machine. Attachment rails 25 are secured to the side plates 24a
and 24b. At one end of the bag machine a web roll WR is mounted on
a shaft 26 which in turn is rotatably carried by cantilevered
supports 28 (only one of which appears in FIG. 1). The web roll WR
contains what is known in the industry as even edged J stock,
meaning, that the web roll contains film which is folded along its
longitudinal median. It is however recognized by those familiar
with bag making machinery that unfolded or rolled stock can be
utilized with a triangular folding board which in effect
continually produces even edged or lipped stock.
The web from the web roll WR is directed to a lip folding apparatus
30 which comprises sets of creasing rolls 32a, 32b, 32c and 32d and
various web folding devices, which are not shown as they do not
form part of the present invention. The web is first received
between creasing rolls 32a then the rolls 32b, 32c and 32d in that
order. The folding apparatus can be arranged to fold the web ends
WE to produce a single fold and thus provide two web layers in the
bag lip or skirt, (also sometimes referred to as a band) as shown
in FIG. 2, or it can be arranged to make a double fold thereby
providing three web layers in the bag lip as shown in FIG. 3. After
the web ends have been folded the web is directed to a pair of draw
rolls 34 and then is threaded in a zigzag fashion through a web
accumulating and tensioning control apparatus 36. The web then
continues from left to right, as viewed in FIG. 1, and is operated
upon by handle bag making mechanism 38 which is the subject matter
of the present invention. The mechanism 38 is supported by the
rails 25. The web then passes between a pair of draw rolls 40 and
it is fed through a reciprocating seal bar structure 42 under which
is mounted an intermittently rotating anvil or seal roll 44. The
bag machine drive is designed to intermittently feed the web a
distance equal to the bag width, generally known as the draw
length.
During the period of time that the web is at rest the seal bar 42
is moved downwardly in pressure engagement with the anvil or seal
roll 44 which at that instant of time is not rotating. When the
seal bar 42 establishes pressure engagement with the seal roll 44
the folded web is transversely welded and severed. The bag produced
is transported to a stacking table 46 by belts 48. The stacking
table 46 is disposed at a slight incline and supported in this
position by struts 50.
The handle bag making mechanism 38 is operated in timed relation
with the drive train of the bag machine by a belt 52 trained about
a pulley 54, which is attached to a shaft of the bag machine drive
and a pulley 56 fixed to a shaft 58 rotatably supported by the bag
machine frame. As will be explained hereinafter the handle bag
making apparatus 38 performs its function on each folded lip of the
web during that increment of time that the seal bar 42 transversely
severs and seals the web.
Referring now to FIG. 6 there is shown an enlarged side elevation
partly in section of the handle bag making apparatus 38. As will be
explained in detail hereinafter, the handle bag making attachment
38 shown in FIG. 6 is provided with a unique drive which
reciprocates both platens toward and away from the film lips
simultaneously and it is provided with means for removing the slug
of film defining the cut-outs. Moreover the mechanism is designed
so that the seal bar structure can be pivoted at least 90.degree.
removing it from the path of the web whenever the bag machine is
shut down or stopped for any period of time greater than one bag
making cycle.
As viewed in FIG. 6 the lefthand side rail 25 has mounted thereon a
depending plate 60 which rotatably supports one end of the shaft 58
and the other, or righthand side rail 25, also mounts a depending
side plate 62 having a journal 64 which rotatably supports the
shaft 58. The handle bag making mechanism 38 is supported on
parallel, transversely extending, guides 65 and 66 having slidably
mounted therebetween, by means of rollers 68, a box like housing
70, suitably supporting slidable plungers 72 and 74 which
contribute to cause reciprocation, respectively, of an upper platen
76 and a lower platen 78. Secured to the housing 70 are two
generally triangular plates 80 and 82 which mount one pair of the
rollers 68. A locking mechanism 84 is provided for securing the
handle bag making mechanism 38 transversely in a direction relative
to the direction of film movement so that the handle bag making
mechanism can be positioned properly with respect to the folded
lips of the web.
The locking mechanism 84 comprises an elongate rod 86 having a
knurled knob 88 pinned on one end thereof. The rod 86 extends
through a clearance hole formed in a cross bar 90 which has its
ends rigidly attached to the triangular plates 80 and 82. The lower
end of the rod 86 is threaded into a transverse clamp bar 92, and
as shown in FIG. 8, the clamp bar extends beyond the lateral guide
rails 66 and 64. On each end of the clamp bar 92 small pins 94 are
secured for the purpose of preventing the rotation of the clamp bar
92 when the rod 86 is turned for either tightening or loosening the
clamp bar 92.
In accordance with one feature of the present invention the drive
for simultaneously reciprocating the platens 76 and 78 toward and
away from each other is accomplished by use of a single cam which
reciprocates the plunger 72 and this motion is transmitted to the
plunger 74. Referring to FIGS. 6, 7 and 8 it will be observed that
a cam 94 is rigidly mounted to the shaft 58 by a dog 96 keyed to
the shaft 58. The outer surface of the cam makes contact with a
roller 98 which is rotatably mounted, by means of a pin 100, to a
bifurcated portion 102 on the lower end of the plunger 72. Those
portions of the plungers 72 and 74 interiorly of the housing 70
carry pairs of rollers 104 and 106 associated, respectively, with
the plunger 72 and the plunger 74. As shown in FIG. 8, the plunger
72 has diametrically opposed flats 108 formed thereon and a shaft
110 extending through that portion of the plunger 72 having the
flats 108. The shaft 110 rotatably supports rollers 104 and on an
extended portion thereof there is rotatably mounted a T shaped
nylon block 112 slidably mounted in a slot 114 (see FIG. 13). In
like manner a shaft 110a rotatably supports the rollers 106 on
plunger 74. A nylon T block 112a is mounted on the end of the shaft
110a and is fitted to slide in a similar slot 114. Reference to
FIG. 13 will show the nylon blocks 112 and 112a in the slots
114.
Pressure engagement of the cam roller 98 (FIG. 6) with the cam 94
is achieved by a compression spring 116 having one end bearing
against the lower end of the plunger 74 and the other end received
in a bore 118 of a structure generally identified by the numeral
120. The structure 120 is attached to the lower surface of the
housing 70 and, as shown in FIG. 8, is formed with a plurality of
webs 122. The housing has a depending portion bored at 123 for
reception of the outer race of a bearing 124. As shown in FIG. 6
the inner race of the bearing is secured to a hub 126 of the cam
94.
Still referring to FIG. 6, motion transferring levers 128 are
pivotally mounted on a shaft 130 extending through a web 132 of the
housing 70. The levers 128 are retained on the shaft 130 by collars
134. The single cam drive operating the two platens 76 and 78
operate in the following manner: When the shaft 58 is rotated by
the belt 52 trained about the pulley 56, the cam 94 is rotated.
When that portion of the cam surface closest to the center of
rotation is encountered by the roller 98 the plunger 72
reciprocates downwardly while at the same time the plunger 74 is
reciprocated upwardly by virtue of the force supplied by the spring
116 bringing the platens in engagement with the folded lips of the
web. In encountering the rise of the cam 94 the plunger 72 is
displaced upwardly and, by virtue of the levers 128, the plunger 74
is moved downwardly against the bias supplied by the spring 116
releasing the platens 76 and 78 from the folded lips of the
web.
The plunger 72 is connected to the platen 76 by having its upper
end slidably received in a bore 127 formed in the platen 76. The
bore 127 is longitudinally slotted at 129 and the bore diameter is
reduced by providing clamping bolts 131 which when tightened shrink
the bore 127 thus firmly engaging the plunger 72. To adjust the
pressure with which the platen 76 imposes on the upper lip UL of
the web, a bolt 136 is disposed through a clearance hole in a
rectangular plate 138 (see FIG. 10) and threaded into a tapped hole
in the upper end of the plunger 72. The bolt 136 is fitted with a
threaded washer 137 serving to prevent axial movement of the bolt
136 when it is turned. With the clamp bolts 131 loosened,
increasing the pressure of the platen 76 takes place when the bolt
136 is turned to raise the plunger 72. The desired pressure is
retained by tightening the clamp bolts 131.
In a generally similar way, the lower platen 78 is provided with
pressure adjustment means. The plunger 74, as shown in FIG. 11, is
received within a bore 148 formed in a depending portion 150 of the
lower platen 78. The depending portion 150 is provided with a
longitudinal slot 152, which, together with bolts 154, constitute a
clamp which firmly holds the upper end of the plunger 74 in the
bore 148. Mounted slightly below the depending portion 150 is a
small rectangular plate 156 bored to receive the plunger 74 and
also slotted to define a clamp. For clamping the rectangular plate
156 to the plunger 74 a bolt 158 is provided. The plate 156 has a
screw 160 passing therethrough and threaded into a bore 162
provided in the depending portion 150. The screw is also provided
with a lock nut 164 which when tightened prevents rotation of the
screw. To adjust the pressure of the lower platen 78 the clamp
bolts 154 are loosened permitting the plunger to slide in the bore
148. Increasing pressure is attained by turning the screw 160 so
that the platen 78 is raised. Then the clamp bolts 154 are
tightened firmly clamping the end of the plunger 74 in its adjusted
position.
According to an important feature of the present invention the seal
bars for making the aligned seals in the folded lips of the web are
mounted so that they can be displaced laterally away from the web
path whenever machine operation is interrupted for more than one
bag making cycle. Further the seal bar structure remains stationary
during normal operation thus simplifying and making more reliable
the wiring for the seal bar heating elements. Referring first to
FIG. 6 it will be seen that a generally inverted L shaped member
166 is mounted on the upper surface of the housing 70 and is formed
with an enlarged boss 168 bored for rotatably receiving a short
stub shaft 170 (FIG. 10). As best shown in FIG. 10, the shaft 170
has a bracket 172 rigidly clamped thereon and on its upper portion
a spur gear 174 is keyed thereto in overlying relationship to the
bracket 172, as shown in FIG. 6. The bracket 172 has a vertically
extending web portion 176 to which is attached, by means of spacers
178, a unitary seal bar and cut-out die mechanism generally
indicated by the number 180. The elongate spacers 178 are rigidly
attached to the vertical web 176 by screws 182 which extend through
the spacers 178 and are threaded into one of the seal bars of the
seal bar structure 180.
To cause rotation of the seal bar structure 180 out of the path of
the web, a power cylinder 184, either hydraulic or pneumatic, is
mounted on a plate 186 by a small angle bracket 188. A projecting
rod portion of the cylinder 184 is suitable rigidly secured to a
rack 190 which meshes with the gear 174. When the stop button of
the bag machine is depressed the head end of the cylinder 184 makes
communication with a fluid under pressure, moving the rack 190 to
the left as shown in FIG. 12 to occupy the phantom outline
position. This action of course causes rotation of the shaft 170 by
virtue of the fact that the spur gear 174 is rigidly attached
thereto and concurrent therewith the bracket 172 assumes the
phantom outline position and obviously carries the seal bar and
cut-out mechanism 180 therewith since they are rigidly connected to
the bracket by the screws 182. In the event the bag machine is
interrupted for one or more cycles the bracket 172 and seal bar and
cut-out mechanism 180 could be pivoted to the phantom outline
position.
In describing the arrangement of the seal bars and the cut-out
mechanism reference is made to FIGS. 11 and 12. Referring first to
FIG. 12 it will be observed that two elongate seal bars 192 and 194
are provided and they are laterally spaced by a pair of blocks 196
secured therebetween by screw fasteners. Conventional tubular
electrical heaters 192a and 194a are mounted in the seal bars 192
and 194 respectively, to heat the seal bars to the temperature
necessary to firmly seal that portion of the web contacted by the
seal bars. Located in the space between the seal bars is the
cutting die 198 which is rigidly fixed in place between the seal
bars by a plurality of screws 200 which extend through clearance
holes in the seal bars 192 and 194 and threadedly engage tapped
holes in the cutting die 198. FIG. 11 shows the cutting dies 198 in
cross section where it will be observed that there are upper and
lower cutting dies 198. The dies are preferably formed with sloping
interior walls to define cutting edges 202. It will be noted that
one of the cutting edges 202 faces upwardly and the other one faces
downwardly in order to simultaneously produce aligned cut-outs in
opposed longitudinal portions of the web W since it is separated,
as shown in FIG. 6, as it passes through the handle bag
mechanism.
In order to guard against sticking of the folded web bands or lips
to the cut-out dies 198 or the seal bars 192 and 194, and to
provide for separation of the folded lips of the web, resiliently
mounted upper and lower stripper plates 204 and 206, respectively,
are mounted between the upper and lower platens 76 and 78. The
stripper plates are formed with bent end portions 207 to prevent
tearing or interference of any nature to the moving web. Referring
to FIG. 10 it will be seen that stripper plate support bars 208,
generally rectangular in form, are mounted on the plate 186. Each
of these support bars 208 are identical in form and function and
accordingly description of one will suffice for both. The support
bars 208 are situated so that no interference is encountered by the
seal bar and cut-out mechanism 180 when it is positioned to its
inactive location as shown in phantom lines in FIG. 12.
The support bars 208 are shown in enlarged scale in FIGS 14 and 15.
Referring to FIG. 14 it will be seen that the support bar 208
comprises a cantilevered portion of reduced thickness 210 in which
are formed a plurality of clearance holes through which are fitted
outboard bolts 212a and inboard bolts 212b. Each bolt has a
compression spring 214 fitted thereon and the ends of the outboard
bolts 212a are attached, either welded or threaded, to the lower
stripper plate 206 while the inboard bolts 212b are attached to the
upper stripper plate 204.
The stripper plates 204 and 206, as shown best in FIGS. 12 and 14
are formed with elongate slots 216 which permit the rounded nose
portions 218 of the seal bars to project through the stripper
plates and make firm engagement with the surface of the platens 76
and 78 to thereby make the line seals in the folded lips of the
web. Each of the stripper plates 204 and 206 are also provided with
a clearance opening 220 so that the cutting die 198 can pass by the
stripper plates 204 and 206 in order to remove a slug of material
from the folded lips of the web to provide the hand grasping
cut-outs H. Stripper plates 204 and 206 could also be rigidly
connected to the platens 76 and 78 for reciprocation with the
platens.
The disclosed handle bag making apparatus of the present invention
is associated with a bag machine having an interrupt circuit which
interrupts the bag making operation for one or more bag making
cycles at the end of a predetermined bag count to enable the
operator to remove a stack of bags from the stacking table 46. A
bag machine having this feature is disclosed in U.S. application,
Ser. No. 787,767 filed Dec. 3, 1968 and application, Ser. No.
821,754 filed May 5, 1969 assigned to the assignee of the present
invention. Reference to these applications, which are included
herein by reference will reveal that when the bag counting
mechanism has reached the end of a count, operation is interrupted
for one or more complete cycles. During this time the seal bar 42
and the draw rolls 40 are rendered inoperative. It is necessary
therefore to provide a similar arrangement for the handle bag
making mechanism 38 to thereby prevent reciprocation of the platens
76 and 78 for one or more bag making cycles. To achieve this result
means are provided for preventing reciprocation of the platens 76
and 78. Such means are shown in FIGS. 8 and 9.
On the top wall 221 of the lower platen structure 78, a pneumatic
or hydraulic cylinder 222 is mounted, by means of a nut 224,
threaded on a stud 226 integral with the cylinder. The cylinder has
the usual projecting rod 228 (FIG. 9) on the end of which is
coupled a dowel pin 230 which is aligned with a clearance hole 232
formed in the rectangular plate 138. At such time that the bag
machine's control circuit calls for interrupt cycle, pressure fluid
is admitted to the head end of the cylinder 222 extending the rod
228 (FIG. 9) so that a large nut 234 makes abutting engagement with
the lower surface of the plate 138 constraining the platens 76 and
78 to remain in their retracted positions. FIG. 9 shows the piston
rod 228 extended and the nut 234 in contact with the plate 138
therein.
When the cylinder 222 has its rod extended, the cam roller 98, on
the lower end of the push rod 72, does not make contact with that
portion of the surface of the cam 94 having the lesser radius. Thus
the cylinder 222 holds the push rod 72 from reciprocating.
At the end of the interrupt cycle pressure fluid from the head end
of the piston 222 is exhausted, retracting the rod 228 and
accordingly conditioning the handle bag making apparatus to resume
its normal operation.
In describing the operation of the handle bag making mechanism 38
insofar as it relates to the action of the platens 76 and 78 in
making the aligned seal and the cut-outs in the web lips reference
will be made to FIGS. 14 and 15. Referring first to FIG. 14 the
platens 76 and 78 are illustrated in their retracted position. The
folded lips of the web W, the upper lip UL and the lower lip LL,
respectively, overlie and underlie the stripper plates 204 and 206.
With the platens 76 and 78 retracted the springs 214 on the inboard
and outboard bolts 212a and 212b locate the stripper plates beyond
the working surfaces of the seal bars 192 and 194 and beyond the
cutting die 198. When the platens 76 and 78 are actuated toward
each other the web lips UL and LL are pressed against the stripper
plates 204 and 206 and continued movement of the platens 76 and 78
toward each other compresses the springs 214 moving the stripper
plates 204 and 206 toward each other. This movement continues until
the rounded nose portion 218 of the seal bars 192 and 194 press the
upper and lower lips of the web against silicone strips 240 on the
working surfaces of the platens to produce pairs of line seal LS,
shown best in FIGS. 4 and 5. While the line seals are being made
the cutting die 198 severs a web portion, commonly referred to as a
slug, from the folded web lips.
The handle bag making mechanism 38 is provided with means for
disposing of the slug of web removed by the cutting die 198.
Reference to FIGS. 6, 14 and 15 will show that the upper and lower
platens 76 and 78 are formed with passages attached to conduits
which are connectable to a vacuum pump. Referring first to FIG. 6
it shows the upper platen 76 having a bore 241 in which is fitted
an elbow 243. A hose 245 is attached, by means of a clamp 247 to
one end of the elbow. The bore 241 communicates with an elongate
passageway 249 (FIG. 11) which is approximately as long as the die
198. The lower platen 78 is bored at 251 (FIGS. 6 and 11) and an
elbow 253 is mounted therein. A hose 255 is connected to the elbow
253. The lower platen is also provided with an elongate passageway
257 approximately as long as the die 198.
Each of the hoses 245 and 255 are connected to a suitable vacuum
pump (not shown). At such time when the platens 76 and 78 make
pressure engagement with the seal bars 192 and 194, and the die
198, making the line seals and the handle cut-outs, the removed web
portions are drawn through the passageways and along the hoses 245
and 255 directing slugs S1 and S2 to a suitable waste container
(not shown). FIG. 15 shows the slugs S1 and S2 in the process of
being conveyed to a waste container.
Reference is made to FIGS. 14 and 15 in describing the action of
the platens 76 and 78. Before the platens 76 and 78 are moved
toward each other they are located as shown in FIG. 14. It will be
noted that the web lips UL and LL are in contact with the stripper
plates 204 and 206. When the platens 76 and 78 are moved toward
each other the web lips are pressed against the stripper plates 204
and 206 by the force supplied by the springs 214. The plungers 76
and 78 continue moving toward each other until the nose portions
218 of the seal bars firmly press into the web lip to make the line
seals LS (FIGS. 4 and 5) while the dies 198 produce the handle
cut-outs H. Slugs S1 and S2 are concurrently removed from the lips
and are drawn through passageways 249 and 257 for delivery to a
waste collection device. After the web lips UL and LL are released
by the platens 76 and 78, returning to the position shown in FIG.
14, that portion of the web is transported one bag length by the
draw rolls 40.
FIGS. 4A and 5A illustrate various styles of cut-outs which retain
the slugs by small tabs T. To produce the style of FIG. 4A, the
cutting edges 202 of the dies 198 are also ground along the dotted
line 260 so that the web lips are not penetrated along this line,
and ground to produce the tabs T1. The style of FIG. 5A is made by
grinding the cutting edges 202 to produce tabs T2. The major
advantage in retaining the slug, during bag production, is that
making a registered stack on the table 46 is facilitated. By
retaining the slug the tendency of projecting edges encountering
the edges of another bag is obviated on the stacking table 46. If
such a condition occurs the bags become skewed, requiring the
operator to manipulate the bags in registry.
The bag style shown in FIG. 4 also retains the slugs. As in the
case of the style shown in FIG. 4A, the arcuate ends 270 of the
cut-out and one of the straight lines 272, extending to and between
the arcuate ends, is cut while no cut is made along a line 274,
parallel to line 272. The remaining slugs serve the purpose of
locking the bag mouth when the slug of one bag panel is passed
through the cut-out of the other bag panel. This also provides a
more comfortable grip.
Although the best mode contemplated for carrying out the present
invention has been herein shown and described, it will be apparent
that modification and variation may be made without departing from
what is regarded to be the subject matter of the invention.
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