U.S. patent number 3,698,289 [Application Number 04/853,659] was granted by the patent office on 1972-10-17 for apparatus for automatic manufacture of handle bags.
This patent grant is currently assigned to CTP Industries Inc.. Invention is credited to Per Bentsen, Seymour Kamins, Norman Rosenberg.
United States Patent |
3,698,289 |
Kamins , et al. |
October 17, 1972 |
APPARATUS FOR AUTOMATIC MANUFACTURE OF HANDLE BAGS
Abstract
Apparatus for the automatic manufacture of thermoplastic carrier
bags of the type formed of thin film of thermoplastic material and
having a thermoplastic handle and closure means secured to the
inner walls of the bag at its mouth. The machine includes apparatus
for transporting a double layer bag blank of thermoplastic
material, inserting a combined handle and closure means into the
open edge of the blank and heat sealing each side thereof to a
respective wall of the blank. Thereafter, the bag blank, with
handle and closure means attached thereto, is transported to a
further station at which a combined sealing and cutting operation
occurs to form separate bags whose side edges are now sealed. A
magazine is provided for storing a plurality of such handle and
closure means and means is provided for feeding one at a time into
the bag blank. The apparatus includes means for adjusting in a
plurality of different ways the position of each handle and closure
means as it is fed into the bag blank.
Inventors: |
Kamins; Seymour (Oceanside,
NY), Rosenberg; Norman (Bayside, NY), Bentsen; Per
(Bronx, NY) |
Assignee: |
CTP Industries Inc. (Brooklyn,
NY)
|
Family
ID: |
25316595 |
Appl.
No.: |
04/853,659 |
Filed: |
August 28, 1969 |
Current U.S.
Class: |
493/194; 383/15;
493/203; 493/226 |
Current CPC
Class: |
B31B
70/00 (20170801); B31B 70/864 (20170801); B31B
70/87 (20170801); B31B 2160/10 (20170801) |
Current International
Class: |
B31B
19/00 (20060101); B31B 19/86 (20060101); B31b
001/86 (); B31b 001/20 (); B31b 001/72 () |
Field of
Search: |
;93/8W,8WA,33,33H,35VL |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Morse, Jr.; Wayne A.
Claims
What I claim is:
1. Apparatus for the automatic manufacture of bags having handles
secured to the inside bag walls at the mouth of the bag comprising
in combination,
means for intermittently moving a double layer bag blank in the
form of a continuous web past a handle inserting and securing
station,
handle inserting means mounted for movement in the direction of
travel of the web and including a magazine for storage of a
plurality of said handles in stacked relationship,
said last-named means intermittently and in timed relationship to
the movement of said web moving at least one handle into the web
mouth,
means exteriorly of said web for securing said handle in said bag
web to a wall of the bag blank,
means for sealing said web at spaced intervals to form successive
bags and also to separate said successive bags,
said web and said handles both being formed of a thermoplastic
material and said handle inserting means supporting heat sealing
means which intermittently contacts at least one outer surface of
said web to heat seal it to the handle inserted between the layers
of said web,
each said handle comprising two detachably secured portions each
having a longitudinal sealing strip and said heat sealing means
comprising two longitudinal heating bars and means for moving said
two bars simultaneously toward the plane of said web to heat seal
each layer of said web to a respective sealing strip,
each said heating bar being mounted adjacent the end of at least
one pivotally supported rocker arm,
and means for at times rotating both said rocker arms through equal
arcs to move said heating bars relative to the plane of said
web.
2. The apparatus of claim 1 in which said rocker bar rotating means
comprises a cylinder, a crank arm rotated by actuation of said
cylinder, a cam member guided in a slot which permits cam movement
only in a direction substantially in the plane of said web, and a
pair of links coupling said cam member to each of said rocker
arms.
3. Apparatus for the automatic manufacture of bags having handles
secured to the inside bag walls at the mouth of the bag comprising
in combination,
means for intermittently moving a double layer bag blank in the
form of a continuous web past a handle inserting and securing
station,
handle inserting means mounted for movement in the direction of
travel of the web and including a magazine for storage of a
plurality of said handles in stacked relationship,
said last-named means intermittently and in timed relationship to
the movement of said web moving at least one handle into the web
mouth,
means exteriorly of said web for securing said handle in said bag
web to a wall of the bag blank,
means for sealing said web at spaced intervals to form successive
bags and also to separate said successive bags,
and means exteriorly of said web becoming at times effective to
exert a frictional restraining force against movement of said
handle in response to said handle inserting means through the
intervening material of the web,
said restraining means including a pressure plate, a solenoid for
at times actuating said pressure plate, and a spring for moving
said pressure plate in a direction opposite to that imparted to
said plate by said solenoid.
4. Apparatus for the automatic manufacture of bags having handles
secured to the inside bag walls at the mouth of the bag comprising
in combination,
means for intermittently moving a double layer bag blank in the
form of a continuous web past a handle inserting and securing
station,
handle inserting means mounted for movement in the direction of
travel of the web and including a magazine for storage of a
plurality of said handles in stacked relationship,
said last-named means intermittently and in timed relationship to
the movement of said web moving at least one handle in to the web
mouth,
means exteriorly of said web for securing said handle in said bag
web to a wall of the bag blank,
means for sealing said web at spaced intervals to form successive
bags and also to separate said successive bags,
and means for spreading apart the two layers of said web to permit
insertion therebetween of said handle,
said spreading means comprising two hinged plates inserted between
the layers of said web and having a length in the direction of web
movement which is in excess of the length of the handle,
said spreading means being located at the point of handle
insertion,
and means for at times forcing said plates apart about said hinge
to separate the layers of the web.
5. Apparatus for the automatic manufacture of bags having handles
secured to the inside bag walls at the mouth of the bag comprising
in combination,
means for intermittently moving a double layer bag blank in the
form of a continuous web past a handle inserting and securing
station,
handle inserting means mounted for movement in the direction of
travel of the web and including a magazine for storage of a
plurality of said handles in stacked relationship,
said last-named means intermittently and in timed relationship to
the movement of said web moving at least one handle into the web
mouth,
means exteriorly of said web for securing said handle in said bag
web to a wall of the bag blank,
means for sealing said web at spaced intervals to form successive
bags and also to separate said successive bags,
said handle inserting means including means for adjusting the
extent of travel of each said handle into the span between the
layers of said web,
said adjusting means comprising a cylinder having a piston with a
predetermined length of its stroke,
means coupled to said cylinder for pushing the bottom-most handle
in said magazine forwardly into the space between the layers of
said web,
and means for adjusting the position of said cylinder relative to
said magazine.
Description
SUMMARY OF THE INVENTION
Carrier bags which are formed of a thin-film thermoplastic material
and which have heat sealed thereto a combined handle and closure
means are now well-known in the art. The handle and closure means
generally comprises two mateable parts, each comprising a
longitudinal sealing strip and an integrally formed U-shaped handle
portion. The sealing strip of each part is adapted to be heat
sealed to an inside bag wall at the bag mouth, and the two handle
portions are provided with an interlocking means so as to enable
the two to be snapped together so that the bag mouth may be tightly
closed as desired but also may be repeatedly opened and closed by
the user.
In the past, the art of manufacture of such bags has provided for
the initial manufacture of the bags themselves but without handles
by using well-known techniques and conventional bag-making
machinery. Subsequent to the manufacture of the bags, they have
been subjected to a wholly, or at least partially, manual operation
wherein the bag mouth is opened, a combined handle and closure
means inserted thereinto, and with each handle portion thereafter
heat sealed to the bag walls. It will be appreciated that this is a
time-consuming and thus costly method of manufacture which has
resulted in an overall cost for such bags which is in excess, by a
substantial margin, of the cost of bags manufactured by the machine
of this invention. Although machines are also known which do have
the capability of inserting web handles into an opened bag mouth
and thereafter heat sealing such handles to the bag walls, such
machines are not capable of providing a wide range of adjustment of
the handle feeding mechanism in a convenient, easily controllable
manner, and thus such prior art machines have been of high cost and
are, moreover, not readily adaptable to quick alteration so as to
accommodate different sizes and shapes of handles and bags.
SUMMARY OF THE INVENTION
The invention provides a machine which makes possible the
completely automatic manufacture of carrier bags with thermoplastic
handles. The machine starts with a roll of a thin film of
thermoplastic material, forms such material into a continuous
double layer web or blank, and opens the web to automatically
insert thereinto a combined handle and closure means. After
properly positioning the handle and closure means, and while both
the web of material and the handle are stationary, a heat sealing
means acts upon the bag walls to seal them to the inserted handle
and closure means after which each bag portion is passed to a
further location on the machine where each individual bag portion
is separated from the adjacent portion to thereby form successive
handle bags.
Although the method of handle bag manufacture as briefly described
above has been known for some time, there has heretofore been no
machine available which is designed specifically for the job of
automatic handle bag manufacture and which provides the several
advantages of the machine of this invention. For example, the
machine of this invention is readily adapted to accommodate handles
and bags of various sizes. The magazine in which the handles are
stored for subsequent feeding into the bag mouth is very readily
adjustable in position, being movable longitudinally along the
machine by riding upon a pair of rails. At the same time, a
vertical adjustment of the handle position as it is fed into the
bag mouth can readily be effected as well by providing for the
tilting, both forward and back, of the handle magazine. In
addition, the extent of "throw" of the handle feed mechanism may
very readily be adjusted as well so as to control the position of
the handle and closure means within the bag mouth. In addition, a
handle storage means is provided which may very readily be removed
from the machine and replaced with one of a different size which is
designed to accommodate handles of different lengths or
configurations.
BRIEF DESCRIPTION OF THE DRAWINGS
In describing the invention, reference will be made to the
accompanying drawings in which:
FIG. 1 is a perspective view of a bag as manufactured without a
handle and, adjoining the bag, is shown a handle and closure means
adapted for insertion into the bag mouth;
FIG. 2 is a schematic plan view of the invention as applied to the
bag-making machine;
FIG. 3 is a front elevation, partially broken away, of the handle
feed mechanism of this invention;
FIG. 4 is a side elevational view of the handle carrying means of
the magazine;
FIG. 5 is a partial elevation section view of the handle magazine
of FIG. 3;
FIG. 6 is a plan sectional view taken along the section line 6--6
of FIG. 5;
FIG. 7 is a partial elevational sectional view of an alternate form
of handle clamping means;
FIG. 8 is a plan view, partially broken away of the apparatus of
FIG. 3;
FIG. 9 is a partial elevational sectional view of the handle
magazine apparatus of FIG. 3;
FIG. 10 is the same view as FIG. 9 but showing an alternate
position of the apparatus in its cycle of operation;
FIG. 11 is a plan view of an alternate means for spreading the bag
mouth to receive a combined handle and closure means;
FIG. 12 is a side elevational view of the apparatus of FIG. 11;
and
FIG. 13 is a partially broken sectional view of a means for
removing a draw roll from the apparatus of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 1 and 2, FIG. 1 illustrates the type of
thermoplastic carrier bag which is manufactured automatically by
the apparatus of this invention, and FIG. 2 illustrates
diagrammatically the manner in which such bags are made by the
machine of this invention. In FIGS. 1 and 2, a sheet of thin-film
thermoplastic material 20 having a fold at 21 and upper and lower
edges 22 and 23 is supplied from a reel 24 to a bag-making machine
25. Quite commonly, the bag-making machine 25 includes the
capability of using a thin film material which is not folded over
in which event the bag-making machine itself provides for the
folding over of the film so as to form a double layer bag
blank.
The machine 25 of FIG. 2 includes a draw roll 26, a clear area 27
in which various operations can be performed and in which
registration of the bag blank and its forward movement can be
controlled as by a photocell 28 which detects markings 29 imprinted
on the film, another draw roll 30, a sealing and cut-off means 31,
and a drive means 32 for synchronizing the aforementioned
components both when pulling the film forward and for at times
momentarily stopping the progress of the film for handle insertion,
handle sealing, and bag cut-off operations. The bag 33 which is
produced by the machine thus has sealed edges 34 and an open end
35.
The handle inserting and sealing apparatus of the invention is
indicated diagrammatically at 40 in FIG. 2 between the draw rolls
26 and 30 and is located adjacent the open edge of the film at 35.
The apparatus 40 includes means for feeding handles 41, one at a
time, and cyclically in synchronism with cut-off and sealing means
31 to position each individual handle 41 at 41a inside the open
side 35 of the film 20 and subsequently to heat seal the film at
both edges to both sides of the handle and closure means 41.
The handle and closure means 41 comprises two mateable portions 42
which are provided with a closure means such as a plurality of
studs and recesses which releasably engage each other when the two
handle portions are pressed together. Once the handle and closure
means is inserted into the bag mouth, the portion 43 on one of the
bag walls is heat sealed to the longitudinal sealing strip 44 of
one of the two handle portions while the oppositely disposed
portion 45 on the opposite bag wall is similarly heat sealed to the
longitudinal sealing strip 46 on the opposed handle portion 44. The
resulting bag, with handle and closure means secured thereto and
with each bag separated from the strip, is shown at 47.
The apparatus 40 is provided, as will subsequently be described,
with means for adjustably controlling the position of the handle as
it is fed into each bag mouth, and such adjustment means is capable
of controlling the position in any of three mutually perpendicular
axes. As will be shown, the adjusting means, while permitting
convenient adjustment, is of relatively simple construction and is
also readily serviceable.
The apparatus 40 comprises a main assembly 50, as shown in FIG. 3,
which performs the handle insertion and sealing operation and also
supports a handle magazine 51. The magazine 51 includes a front
plate 52, back plates 53 and 54 (see FIG. 3), end plates 55 and 56,
and pocketing plates 57 and 58. Pairs of slots 59a, 59b, 59c, and
59d accommodate the above-mentioned plates 57 and 58 at different
positions, thereby forming a compartment of controllable width so
as to accommodate handle and closure means of varying lengths. For
example, when using handles whose longitudinal sealing strips have
a length such as is shown in FIG. 3 at 41, the plates 57 and 58 are
respectively inserted in slots 59b and it will be understood that
handles of greater length may require the positioning of the
members 57 and 58 in either slot 59c or 59d, whereas shorter length
handles may require positioning of members 57 and 58 in the slots
59a. It will be noted in FIG. 3 that the bottom edge 61 of the
magazine 51 is positioned slightly above the top of the lowermost
handle. This permits only the bottom handle to be pushed out from
under the stack of handles by a means subsequently to be
described.
The vertical position of the magazine 51 may readily be adjusted so
as to vary the distance of its bottom edge 61 above the upper
surface of member 77 so as to adjust to varying thicknesses of
handles. This is accomplished by providing shouldered key members
62 on each side of the magazine which are adjustable in position by
means of bolts 62a. The narrow portion 62b slides within slots 63
formed by the bars 64 which are secured to the main assembly 50 as
shown in FIG. 5. However, the shoulder portions 62c do not fit
within the slot 63 and thus provide a stop which controls the
vertical position of the magazine and, from the description
previously given, it will be appreciated that the preferred
position is one in which the spacing between the lowermost edge 61
of the magazine and the topmost surface of member 77 is slightly in
excess of the thickness of the handle and closure means which is to
be fed into the double-layer web.
Each magazine may further be provided with photoelectric cells 65
and 66 which receive light from light sources 67 and 68,
respectively. The light sources 67 and 68 are placed behind the
plate 52 and illuminate the photocells through apertures 69 and 70
in both the front and back plates. When the magazine is full of
handles, light from both light sources is prevented from impinging
upon the associated photocell, but when the supply of handles is
reduced to a level where the upper cell 65 receives light from its
associated light source 67, a warning buzzer or other signal (not
shown) is triggered to indicate to the operator that additional
handles should be inserted into the magazine. If the supply of
handles is allowed to go lower yet, to a level where the cell 66
receives light from its associated light source 68, another circuit
may be triggered which will stop further operation of the entire
machine and thereby prevent inadvertent operation of the machine
without handles which wastes material.
The apparatus 50 comprises two vertical plates 75 and 76 which are
bolted to a horizontal table surface 77. As shown in FIG. 5, each
of a pair of upper rocker arms 79 is spindled at bearings 80 on the
two side plates 75 and 76. A pair of lower arms 81 is similarly
spindled to the same plates at bearings 82. At the work end of the
arm, heat sealing assemblies 83 and 84 are diagrammatically
illustrated in FIG. 5. At the actuating end of the arm, the arms
are linked by a pair of rotatable members 85, 86 to a pair of cam
rollers 87 which are limited to a horizontal traverse only as a
result of their being engaged in a pair of guides 88 attached
respectively to plates 75 and 76.
A rod 89 is supported in a pair of bearings 90 (see FIG. 3) and is
provided with a pair of cranks 91 with each crank being coupled, in
turn, with members 85 and 86 by a respective one of a pair of
members 92. At the center of rod 89, another crank 93 is provided,
which is engaged between springs 94 on the piston 95 of an air
cylinder 96, the air cylinder 96 being supported pivotally at the
center of rod 78. Collars 97 may be adjusted on actuator rod 95 for
both optimum position and spring pressure in the operating
position. Shaft 78 (FIG. 3) is fixedly coupled to the side members
75 and 76.
It will be apparent from the disclosures of FIGS. 3 and 4 that
actuation of the cylinder 96 in such a manner as to cause its
piston 95 to be driven outwardly, will cause crank arms 91, and 93,
to rotate clockwise about shaft 89, thereby causing cam rollers 87
to move to the right in FIG. 5 and thereby rotating both members 79
and 81 about their respective pivots 80 and 82 so as to cause the
heat sealing assemblies 83 and 84 to move equal distances over
arcuate paths toward the plane of the bag as indicated at 98.
Similarly, retraction of piston 95 causes both heat sealing
assemblies to move equal distances over arcuate paths away from the
plane of the bag at 98. It will thus be appreciated that the
mechanism thus far described not only permits both the heat sealing
assemblies 83 and 84 to be moved away from the plane 98 during
times other than when sealing is taking place, but will always
result in the assemblies 83 and 84 being brought together at the
plane 98 so that heat sealing can be effected without moving
vertically the bag and the handle inserted therein for sealing.
FIG. 7 illustrates an alternate apparatus for obtaining essentially
the same result as with the apparatus of FIGS. 3 and 5 already
described. Thus, FIG. 7 shows two air cylinders 99 which are
pivotally supported and engage with the ends of the rods 79 and 81
at their ends journaled at 100. The rods, being pivotally supported
at 80 and 82, thus move over equal arcuate paths at their far ends
and thus permit heat sealing assemblies comparable to 83 and 84 of
FIG. 5 to be moved toward the film plane. For clarity, the springs
and collars are omitted in FIG. 7, but it should be understood that
they may be installed in a manner similar to that shown in FIG.
5.
Referring now to FIGS. 8, 9, and 10, the means for moving each
handle 41 from the bottom of the stack of handles in magazine 50
comprises two pusher bars 101, a connecting plate 102 which is
slidable in ways 103 attached underneath plate 77, and an air
cylinder 104 connected to plate 102 at plate bracket 105. Bars 101
extend through slots 106 in plate 77 and bear against the
longitudinal sealing strip portions 60 of the handle. Actuation of
the air cylinder 104 moves the bottommost handle in the stack from
the position shown in FIG. 9 to the position shown in FIG. 10.
It is desirable that a means be provided which will permit accurate
adjustment of the extent of forward movement of each handle 41
under the influence of pusher bars 101 in order that each handle
assembly 41 will be accurately positioned relative to the mouth of
the bag. This is accomplished by mounting the air cylinder 104 on
plate 107 which is slidable on ways 108 in plate 77, said plate 107
being made adjustable by a threaded locking means 109. This
adjustment means permits the use of a cylinder with a fixed amount
of throw of its piston while at the same time permitting accurate
adjustment of the extent of forward movement of each handle
assembly upon the actuation of the cylinder 104. Thus, the cylinder
body itself is mounted on the plate 107, and the position of the
latter plate 107 can be adjusted in or out relative to the mouth of
the bag by turning the adjusting screw 109 by means of knurled
handle 109a. In this way, the ultimate position of the piston of
the actuated cylinder is adjusted and thus also the final position
of each handle assembly 104 within the bag mouth.
A bar 120 secured between the two side plates 75 and 76 supports a
solenoid 121 which actuates a pressure plate 122 pivotally
supported at a bracket extension of bar 120. A spring-biased
sliding means 123 is introduced between the solenoid armature and
plate 122. At the time that the cylinder 104 is actuated to push a
handle into the bag mouth, the solenoid 121 is actuated also so as
to rotate the free end of the pressure plate 122 downwardly about
its pivot and thereby exert a frictional force against the
forward-moving handle assembly 41. This is necessary in order to
ensure that the handle has its forward movement restrained since
otherwise it would continue to move by inertia further into the
mouth of the bag beyond the stopping position of the piston of
cylinder 104, it being remembered that the piston moves the handles
forward with extreme rapidity so that the moving handle acquires an
appreciable inertia. However, after the sealing operation is
completed, and it is intended to move the bag blank with attached
handle to the next station, it is then desired that all restraining
pressure on the handle be removed and, at such time, the solenoid
121 is de-energized so as to rotate the pressure plate 122 upwardly
above its pivot point and thereby remove any pressure from the
handle.
It will be appreciated that a means must be provided to separate
the two layers of the bag blank prior to attempting to insert a
handle assembly therebetween. This can be readily accomplished as
shown in FIG. 8 by providing a bar 124 which is secured to the
handle inserting apparatus and which includes a projecting portion
which lies between the two layers of film 22 and 23 so as to
separate them. However, it has been found that the use of a
separating member such as 124 may at times produce certain
difficulties, chiefly that of producing a ripple or distortion in
the film which prevents it from being fed smoothly and without
wrinkles through the machine. This problem may be avoided by
employing a means such as is illustrated in FIGS. 11 and 12. A
bracket 125 is provided which is pivotally supported on an upper
spreader yoke 126 and a lower spreader yoke 127. The yokes are
biased toward each other by a helical spring 128. Interposed
between the yokes is a pivotal member 129 spindled in bracket 125
and having arms 130 and connected by a crank 131 to an air cylinder
132. In FIG. 12, the apparatus is shown in the position it assumes
when the air cylinder 132 has its piston extended so as to rotate
member 129 and separate the two spreader yokes 126 and 127. Such
apparatus, when inserted between the two opposed thermoplastic
films, causes the film to be spread along its sealing length so
that its edges remain parallel and even. During the time that the
film is moved, the spreader yokes 126 and 127 are, of course,
closed, and it will be noted that these members 126 and 127 and
also the crank arm 131 all lie totally within the thickness of
bracket 125 so that film abrasion and distortion is minimized.
Heat sealing assemblies 83 and 84 each comprise a pair of brackets
110 attached to arms 79 and 81, respectively, and supporting
between the brackets a bar 111 and two rotatable members 112. At
the edge of bar 111 is affixed a heating unit 113 of the Calrod
type from which electrical connections (not shown) are brought
forth. A woven teflon belt 114 wound around one member 112 and
passing over either 113 is tightly re-wound on the other member
112. The belt is therefore renewable at the heating edge by
loosening said screw 15 and turning knob 116. The aforementioned
assemblies 83, 84 are removable at fasteners 117 for
interchangeability when handles of differing lengths are
needed.
After the handle is attached to the bag mouth, it is necessary to
provide a support for the bag mouth which is now weighted with the
weight of the handle. In FIG. 2, such support is generally
indicated as a platform 135. However, as will subsequently be
shown, it is a feature of this invention that the apparatus 40
shall be adjustable longitudinally along the machine so as to
accommodate bags and handles of different sizes, and it may
therefore be necessary to move the apparatus 40 to a position 40a
as shown in FIG. 2. With such movement to the position 40a, it
still becomes desirable to provide a support for the handle and bag
immediately adjacent the handle sealing station. This is
accomplished, as shown in FIG. 3, by providing a belt 136 which is
secured at its one end at 137 to a fixed support and which then
passes around rollers 138, 139 and 140 and is finally attached at
its other end to a fixed bracket support 141. Interposed between
roller 140 and attachment point 141 is a weighted idler roller 142
which rests upon the belt 136. Thus, as the apparatus 40 is moved
in position to right or left in FIG. 3, it can be seen that there
will at all times be a section of belt 136 immediately adjacent the
lefthand edge of the apparatus 40 and extending over to the fixed
support 137 which is capable of supporting the bag and the attached
handle, and such support is at all times available irrespective of
the position of the apparatus 40.
Referring to FIGS. 3, 5 and 6, the apparatus shown is provided with
an upper rail 150 and a lower rail 151. Brackets which are attached
to side plates 75 and 76 each spindle a load-bearing roller 152 and
a pair of guide rollers 153, 154, whose axis of rotation is at
right angles to that of support roller 152. It can readily be seen
that the center of gravity of the apparatus of FIG. 5 is well above
and to the left of the rollers 152. Accordingly, only one
additional roller 155 need be provided at the bottom, and this
roller is spindled at each bracket 156 secured to the bottom of
plates 75, 76, and with the roller 155 engaging the bottom rail
151.
The film plane has been indicated in FIG. 5 by the reference
character 98, and it is apparent that each handle assembly should
be fed forward generally along or in the plane of the film at 98.
However, it will be recognized that the film plane 98 represents an
ideal and that the exact plane between the two layers of film at
which the handle should be inserted may differ slightly above or
below the ideal at 98. In order to provide adjustment to
accommodate for variation in the vertical position of feed of each
handle assembly, an adjustment means is provided which effectively
permits rocking the entire apparatus of FIG. 5 about its support at
the upper edge of the upper rail 150 by interposing an adjustable
eccentric 157 between bracket 156 and roller 155. This effectively
permits adjustment of the center of rotation of roller 155 relative
to the forward edge of member 75, thereby permitting a slight
rocking of the entire apparatus so that a clockwise rocking about
its support will tend to lower the plane at which successive handle
assemblies are fed forward whereas counterclockwise rotation will
have the opposite effect.
The apparatus 40 may be positioned along the rails by providing a
housing 160 on plate 75 which supports a shaft having a worm
control knob 161 and a worm 162 inside the housing and cooperating
with a worm wheel 163 which through its shaft operates a pinion 164
engaged with rack 165 positioned along the bottom edge of rail 150.
It will thus be appreciated that rotation of the knurled wheel 161
permits, in effect, a micrometer adjustment of the position of the
apparatus 40 along the rails 150 and 151.
Such accurate positioning is required because of the necessity of
having the center of each handle means positioned within the web at
a predetermined multiple, i.e. one and one-half, two and one-half,
etc. bag widths from the position of the cutting and sealing
knife.
A microswitch 170 is shown in FIGS. 9 and 10. In FIG. 9, the switch
remains unactuated, but in FIG. 10, the bar 79 has moved upwardly
to a position where the switch is actuated. With the apparatus in
the position shown in FIG. 10, the heat sealing assemblies 83 and
84 are in a position to heat seal the bag walls to the longitudinal
sealing strips of the handle assemblies, and actuation of switch
170 as shown in FIG. 10 provides an input signal to a current pulse
generation (not shown) to supply a predetermined pulse of current
to the sealing sub-assemblies 83, 84.
Referring to FIGS. 2 and 13, it can be seen that the draw rolls 26
and 30 are so positioned that access thereto for removal from the
machine and replacement may be difficult and time-consuming. In
fact, with some of the prior art machines, several hours of labor
may be required to remove a draw roll and replace it. The means of
assembly of the draw rolls of this invention as shown in FIG. 13
greatly reduces the amount of time and effort required to effect
this machine repair. Thus, as shown in FIG. 13, bearings 175 and
176 are press fitted on the shaft of draw roll 26. Bore 177 in
machine member 178 receives bearing 175. A collar 179 is bored to
receive bearing 176. Collar 179 is flanged at 180 for bolting to
machine member 181. The diameter of the collar and of its clearance
hole 182 in member 181 are suitably sized to pass the roller
through for removal. To secure the outer races of the bearing
against rotation, set screw 183 or other means known in the art may
be employed.
FIG. 14 schematically illustrates the basic cycle of operation of
the apparatus of the invention. It will be apparent to one skilled
in the art that a multiple cam switch (not shown) operated from the
main drive shaft (not shown) of the machine may be used to provide
various timing functions and as is also generally known in the art,
various successive operations are actually overlapped in their time
relationship so as to provide as short a cycle time as possible. As
FIG. 14 illustrates, the beginning of the cycle may be considered
as the time when the film layers 22, 23 are transported by the draw
rolls 26 and 30. When the film has been transported the required
distance, as determined by the photocell 28, the film is stopped
and the sealing bar 31 (FIG. 2) is lowered to perform a side seal
and cut-off operation. At the same time, the film spreader (see
132, FIG. 12) is actuated to separate the two layers of film 22,
23. Shortly after the film spreader has started to open the bag
mouth, the handle positioning operation is commenced by actuation
of cylinder 104, at which time the solenoid 121 may also be
actuated to provide a restraining force against the handle assembly
as it is pushed into the bag mouth. Shortly thereafter, the
cylinder 96 is actuated in order to bring the heat seal
sub-assemblies 83, 84 together to thereby seal the bag walls to the
handle assembly. The heating elements 113 are energized shortly
thereafter to provide an impulse of heat for effecting the sealing
operation. Then the current is shut off to allow the molten plastic
to solidify under pressure to effect a good heat seal; as the
sealing jaws begin to open, the film again is transported. During
the aforementioned heat and dwell cycle, the film spreader is
retracted, the handle positioner is also retracted, the handle
restraining plate is lifted, and all other mechanisms are returned
to their original position to start their next cycle.
* * * * *