US3706625A

US3706625A - Machine for fabricating bag handles

Info

Publication number: US3706625A
Application number: US114535A
Authority: US
Inventors: Elwyn David Jones; Edward Kenneth Rowley
Original assignee: Canadian Industries Ltd
Current assignee: NATIONAL TRUST Co A TRUST Co OF ONTARIO
Priority date: 1970-10-07
Filing date: 1971-02-11
Publication date: 1972-12-19
Anticipated expiration: 1989-12-19
Also published as: CA900240A

Abstract

A machine for attaching handles to components of carrying bags. The machine forms loop handles from a length of heat-sealable strip and heat-seals the ends of the handle loop to a rectilinear heat-sealable strip. The handle assembly so formed is available for heat-sealing to the open edge of a carrying bag. The rectilinear strip serves to attach the handle to the bag and to strengthen the open end of the bag.

Description

United States Patent Jones et al.

[54] MACHINE FOR FABRICATING BAG HANDLES 72] Inventors: Elwyn David Jones, Beloeil; Edward Kenneth Rowley, Beloeil Station,

both of Canada [73] Assignee: Canadian Industries Limited, Montreal, Quebec, Canada [22] Filed: Feb. 11, 1971 [21] App]. No.: 114,535

[30] Foreign Application Priority Data Oct. 7, 1970 Canada ..O95086 [52] US. Cl. ..156/517, 156/306, 156/522,

156/552, 156/566, 156/583 [51] Int. Cl. ..B31b 1/14, B32b 31/18, B29c 27/02 [58] Field of Search ..156/510, 517, 522, 545, 552, 156/566, 583, 306, 309

[56] References Cited UNITED STATES PATENTS 3,635,780 l/l972 Griggs et a1. ..l56/583 2/1972 Gaunt et a1. ..l56/552 X 3,650,873 3/1972 Smith et a1.... .....l56/583 X 3,664,238 5/1972 Baxter et al.. .....l56/566 X 3,671,350 6/1972 Westlake ..l56/510 X 3,008,865 11/1961 Hayes et a1. ..l56/510 3,043,729 7/1962 Seiden ..156/5 10 X 3,196,067 7/1965 Techtmann... .....156/583 X 3,392,636 7/1968 Lindley ..l56/522 X Primary Examiner-Harold Ansher Attorney-Alexander 0. Mclntosh 57 ABSTRACT A .inachine for attaching handles to components of carrying bags. The machine forms loop handles from a length of heat-sealable strip and heat-seals the ends of the handle loop to a rectilinear heat-scalable strip. The handle assembly so formed is available for heatsealing to the open edge of a carrying bag. The rectilinear strip serves to attach the handle to the bag and to strengthenthe open end of the bag.

6 Claims, 12 Drawing Figures PATENTED DEC 1 9 1912 3, 7 06, 625

sum

1 or 8 INVENTORS Elwyn Dov id JONES Edward Kenneth ROWLEY mamw PATENT AGENT PA TENTED 19 I97? 3. 706, 6 25 sum 2 0F 8 FIG 2 INVENTQRS Elwyn Duv idJGNES Edward Kenneth ROWLEY MdkuJ-ZJ PATENT AGENT i-Lil i PATENTEDHEB 19 I972 SHEEI 3 0F 8 nvvmiqns Elwyn DdvidJONES Edward Kenheth ROWLEY RA TENT AGENT PA TENTEU BEE 3. 706.625

sum u [If 8 Ma /29 /23 30 M4 2 /26 Mm 2/4 /25 /2/ /20 /22 N9 //z /4 #6 wU l I 7 //a I T I I A n I //0/ 7 my I FIG. 4

INVENTORS Elwyn David JONES Edward Kenneth ROWLEY M0, MW

PATENT AGENT P A TE N TED 19 i973 3, 7 O6. 625

sum 5 or 8 INVENTORS I Elwyn David JONES Edward Kenneth ROWLEY M a )1 Lu PATENT AGENT PATENTEI] DEC 19 I972 SHEET 6 0F 8 INVENTORS Elwyn Dav id JONES Edward Kenneth ROWLEY PATENT AGENT PATENTEUUEE 19 m2 3.706.825

sum 7 OF 8 l I l INVENTORS Elwyn Duvld JONES J 1 im ii 9%. m h

Edward Kenneth ROWLEY M440. MM

PATENT AGENT PATENTEDBEB19 19 2 3,706,625

SHEET 8 OF 8 INVENTORS Elwyn David JONES Edward Kenneth ROWLEY Mahiau PA TENT AGENT MACHINE FOR FABRICATING BAG HANDLES This invention relates to a machine for attaching carrying handles to bags and to the bags soproduced.

During the manufacture of carrying bags the step of attaching the handles is normally the most intricate. Frequently the step involves manual positioning of the handles prior to fastening them to the bag. The manual operation imposes a limit to the rate of bag manufacture and its elimination is necessary in high speed manufacture of carrying bags.

Carrying bags, although commonly fabricated from paper, are increasingly being made from heat-sealable plastic film such as polyethylene or polypropylene. During the manufacture of plastic carrying bags having loop handles it is usual to attach the carrying handles by heat-seals to the bag mouth. When this operation is to be carried out automatically at high speed it is necessary to provide an apparatus that measures out correct lengths of handle material and positions the ends of the looped handle in position for sealing. This has been achieved by the present invention which provides a machine that heat-seals looped plastic handles to strips of plastic material or plastic coated material to form either bag handles directly or a handle unit. This handle unit can later be heat-sealed to the mouth of a plastic carrying bag. By means of the machine of this invention it is possible to reduce greatly the number of manual operations required in the manufacture of carrying bags.

It is therefore a primary object of this invention to provide a means for automatically attaching handles to carrying bags. Additional objects will appear hereinafter.

The machine of this invention comprises:

1. means for providing a predetermined length of a first strip of heat-scalable material,

2. two co-operating heat-sealing members,

3. means for positioning the first strip in rectilinear configuration between the two heat-sealing members,

4. means for providing a predetermined length of a second strip of heat-sealable material,

5. means for holding the second strip in rectilinear configuration parallel to but separated from the first strip,

6. two swivel clamps located adjacent to the heatsealing members and adapted to clamp the second strip in rectilinear configuration at positions distant from the strip extremities by an amount sufficient to provide a portion of strip for heat sealing to the border of the first strip,

7. means for swivelling the swivel clamps in mutually reverse directions in such sense as to place the two ends of the second strip between the heat-sealing members and adjacent to the border of the first strip positioned therebetween,

8. means for compressing the heat-sealing members together thus heat-sealing the two ends of the second strip to the border of the first strip, the second strip being in loop form,

9. means for withdrawing the sealed-together strips from between the heat-sealing members, and

10. means for cutting the first strip carrying the loop of second strip to desired length.

It is convenient to provide means for cooling the sealed-together strips, said means acting immediately after the sealing operation. By cooling the seal, distortion of the handle unit is minimized in succeeding operations.

It is convenient to employ paper tape coated on one side with plastic as the first heat-scalable strip. By using a double layer of this tape with the non-scalable paper surfaces in contact it is possible to fabricate two handle units at the same time. This is desirable since each carrying bag requires two of the handle units. Thus the two units produced with the plastic coated sides of the tape on the outside are in proper'configuration for directly sealing to the mouth of a plastic bag.

If paper backed plastic is not employed for the first strip it is necessary when attaching two handles simultaneously to interpose a seal preventing plate between the two layers of heatssealable material when these are sealed.

The invention is illustrated in the accompanying drawings wherein:

FIG. 1 is a front elevation of the machine;

FIG. 2 is a plan view of the machine of FIG. 1;

FIG. 3 is an enlarged view of part of FIG. 1;

FIG. 4 is a sectional view along line IV-IV of FIG. 1;

' FIG. 5 is a side elevation, partly in section of a heatsealing unit;

FIG. 6 is a side elevation of a tape supply unit;

FIG. 7 is a diagrammatic view of the strip clamping devices and sealer bar unit, a handle being clamped in position;

FIG. 8 is a diagrammatic view similar to FIG. 7 but showing the swivelling handle clamps turned to place the ends of the handle between the sealer bar and a length of heat-sealable strip;

FIG. 9 is a diagrammatic view of a handle unit after sealing;

FIG. 10 is a diagrammatic view of the pneumatic and electrical control system of the machine;

FIG. 11 is a perspective view of two handle units in position for heat-sealing to a partially fabricated plastic bag; and

FIG. 12 is a perspective view of the bag of FIG. 11 in completed form.

The machine illustrated in the drawings is capable of fabricating two handle units simultaneously using plastic coated tape as the tape to which the loop handles are sealed. Clearly it will also fabricate single handle units using only part of the tape handling facilities.

The tape for making the bag handle units is drawn from reels mounted on supply unit 1. This is show in detail in FIG. 6. Paper tape coated on one surface with heat-scalable plastic is stored on reels 2, while plastic tape for handles is stored on reels 3. Tape from the reels is carried by means of a series of guide rolls to the handle assembly unit. Tape from reel 2 passes over rolls 4, 5, 6, 7 and 8 fixed to the frame of the unit and

movable rolls

9 and 10 carried by movable arm 11.

Rolls

9 and 10 maintain the tape taut during operation of the machine. Similarly tape from reel 3 passes over fixed rolls 12, l3, l4 and 15 and movable rolls 16 and 17 carried by movable arm 18. There are of course two sets of tape supply reels and guide rolls carried on opposite sides of the frame of the supply unit.

Two lines of plastic coated paper tape taken from guide rolls 8 are combined with paper sides in contact and passed over guide roll 19 to guide plates 20. Guide plates 20 comprise two plates separated by a distance sufficient to keep the two tapes in contact as they pass through the handle sealing station. At the handle sealing station the guides are narrower in order to expose the major part of the tape for sealing purposes. The tape is drawn through the handle sealing station by intermittent motion in increments equal to the length of a handle unit, this metering action being provided by draw rolls 21 and 21A.

The tape for the. handles passes from guide rolls 15 and in double line is carried over

rolls

22 and 23 to an inching unit 24. Unit 24 serves to advance the tape ends a short distance through slots 25 in plate '26. It is constituted by a sliding member 27 that slides horizontally on cylindrical guides 28. Member 27 is provided with slots 29 to carry two tapes and two spring loaded dogs 30 pressing against a central spacer 31 and which serve to grip the tapes. Sliding member 27 is actuated by air piston-cylinder unit 32, the piston of which is attached to 27. The cylinder of unit 32 is carried by cross piece 33 which itself is attached to the ends of guides 28. Cross piece 33 is provided with two spring loaded dogs 34 that press against central spacer 35 and serve to grip the tapes. Inching unit 24 is attached to plate 36 of the frame of the machine.

Also attached to plate 36 is air piston-cylinder unit 37 which operates tape shear 38. Shear 38 in co-operation with plate 26 serves to sever the tape.

The two ends of tape issuing through slots 25 are gripped by draw clamp 39. Draw clamp 39 slides on cylindrical guides 40 and 41 which pass through bores in the body of the clamp. Guides 40 and 41 are supported by

plates

36 and 42 of the machine frame. The clamp jaws are formed of two movable members 43 and 44 and a fixed member 45. Movable members 43 and 44 slide in slots in the body of the clamp permitting motion in a vertical sense. The jaws are operated by air piston-cylinder unit 46, the piston of which is attached to an extension of jaw 44 and the cylinder to an extension of jaw 43. Clamp 39 is drawn along guides 40 and 41 by double acting piston-cylinder unit 48, the piston 49 of which is attached to clamp 39. The cylinder of unit 48 is attachedv to frame plate 36. Control rod 50 slides in bores in

frame plates

36 and 42 and serves to operate a two position air valve V3 (FIG. 10) at each end of the traverse of draw clamp 39. Arms 51 and 52 on rod 50 contact the valve V3. A projection on clamp 39 actuates control rod 50 by pressing against adjustable stops on rod 50 one of which is shown at 53.

When the two lengths of tape have been drawn out through slots 25 by clamp 39 they pass within the jaws of swivel clamps 54 and 55. This is due to the position of slots 25 relative to the two sets of clamps. Draw clamp 39 is adapted to grip one edge of the tape whereas swivel clamps 54 and 55 are adapted to grip the other edge (see FIG. 7). Each swivel clamp is fitted with two movable jaws and one fixed jaw. Swivel clamp 54 thus has movable jaws'56 and 57 and fixed jaw 58. The movable jaws pivot about hinge 59. Extension 60 of movable jaw 56 serves to operate air valve V4. Similarly swivel clamp 55 has movable jaws 61 and 62 and fixed jaw 63. The movable jaws pivot about hinge 64.

The swivel clamp jaws are actuated by

air pistoncylinder units

65 and 66, the upper movable jaws being affixed to the cylinder and the lower jaws to the piston.

The swivel clamp jaws are attached to the upper ends of the vertical parts 67, 69 of L-shaped members, the

horizontal parts

68, 70 of these L-shaped members being fixed at their free ends to

vertical shafts

71 and 72 respectively.

Shafts

71 and 72 fit in hearings in

blocks

73 and 74.

Blocks

73 and 74 are attached to plate 75 of the frame of the machine. The lower ends of

shafts

71 and 72 are attached to intermeshing sector gears 76 and 77. An extension 78 of sector gear 77 is linked to clevis 79 carried by the piston of double action air piston-cylinder unit 80. Piston-cylinder unit 80 is fixed to shaft 81 which pivots in bracket 82. Bracket 82 is attached to plate 75 of the frame of the machine.

The action of piston-cylinder unit 80 turns the two swivel clamps 54 and 55 in mutually reverse directions, causing the swivel clamp jaws to sweep through an arc in the direction of the rear of the machine,'as can be seen in FIG. 8. This brings the ends of the clamped tapes between the two

sealer bars

83, 84 of a heat-sealing unit (FIGS. 2 and 5).

The sealer bars are of known type fabricated from metal and containing internal electrical heating elements. The sealer bars are carried at the ends of hinged

arms

85, 86, the other ends of these bars being connected to double action air piston-cylinder unit 87. The air cylinder is linked to clevis 88 carried by the end of arm 85, while a clevis 89 carried by the end of the piston is linked to the end of arm 86. The arms have short shafts 90, 91 journalled in bearings in support 92. This support is attached to the frame of the machine. Each arm also has a gear 93, 94 attached to its shaft, these gears being in mesh. The action of piston-cylinder unit 87 thus is to compress or retract

sealer bars

83 and 84.

At 95 is shown a seal cooling unit which is identical in design to the above described heat-sealing unit except that instead of heating elements the bars 96 contain ducts for the passage of cooling water.

, Draw roll 21 which draws the tape with sealed on loop handles from the sealing station is driven intermittently by electric motor 97. Motor 97 acting through reduction gear 98 and electric clutch 99 turns sprocket wheel 100. Sprocket wheel 100 drives a second sprocket wheel 101 by means of chain drive 102. Sprocket wheel 101 is mounted on shaft 103 to which is attached crank 104. Shaft 103 is supported by

hearings

105 and 106 attached to the frame of the machine. Shaft 103 carries three

cams

107, 108 and 109 which operate three electrical limit switches LS-l, LS-2 and LS-S (FIG. 10). Attached to the end of shaft 103 is electric brake 110, anchored to the machine frame by member 111.

The motion of crank 104 is transmitted to arm'112 by means of connecting rod 113. The point of attachment of rod 113 to crank 104 is variable in order that the draw capacity of draw roll 21 can be adjusted to suit the size of handle being manufactured. Arm 112 is fastened to the end of short shaft 1 14 which in turn is mounted in bearings carried by

brackets

115 and 116. Shaft 114 is connected to spur gear 117 through unidirectional clutch 118. Gear 117 meshes with small spur gear 119 mounted on shaft 120. Shaft 120 is restricted to rotation in one direction by the action of unidirectional clutch 121 attached to the shaft end. Clutch 121 is anchored to the machine frame through arm 122. Shaft 120 is mounted in bearing in brackets 123 and 124 attached to the machine frame. Shaft 120 carries spur gear 125 which meshes with spur gear 126 on shaft 127. Shaft 127 is mounted in bearings in brackets 123 and 124. Shaft 127 serves as pivot for draw roll carrier 128, two extensions of which, 129 and 130, are mounted on the shaft. Carrier extension 129 is fitted with an adjustment screw 131 to permit the adjustment of the working spacing of draw roll 21. Draw roll 21 is mounted on shaft 132 journalled in carrier 128. Shaft 132 carries also a spur gear 133 meshing with spur gear 126. Lower draw roll 21A is carried by a shaft which rotates freely in bearings in brackets 123 and 124. It thus can be seen that the rotation of crank 104 acting through rod 113 and arm 112 causes spur gear 117 to turn in one direction only. The unidirectional rotation of gear 117 is transmitted through

gears

119, 125 and 126 to gear 113 mounted on the draw roll shaft 132 causing rotation of draw roll 21.

The mounted looped handles pass from the draw rolls 21, 21A to a cut off station where individual handle units are separated. The cut off is mounted on adjustable bracket 134. The cut off comprises knife 135 acting against block 136 to sever the handle support. Knife 135 is attached to the end of the piston of double acting air piston-cylinder unit 137. The air cylinder is fixed to bracket 134. Knife 135 is fitted with two cylindrical guides 138 which slide in bores in the air cylinder support. The cut off handle assemblies fall into chute 139.

The operation of the machine is co-ordinated by a combined pneumatic and electrical control system illustrated in FIG. 10. This comprises 17 pneumatic valves designated V1 to V17, actuated as follows:

V1 is a 3-way mechanically actuated spring return valve actuated mechanically by inching cylinder 32,

V2 is a 3-way mechanically actuated spring return valve actuated mechanically by draw clamp cylinder 46,

V3 is a 5-way mechanically actuated mechanical return valve actuated mechanically by draw cylinder 48,

V4 is a 3-way mechanically actuated spring return valve actuated mechanically by swivel clamp cylinder 65,

V5 is a 5-way air actuated spring return valve actuated pneumatically by air from V4,

V6 is a 5-way mechanically actuated, air return valve actuated pneumatically by air from V5 and mechanically by shear cylinder 37,

V7 is a 3-way one way cam actuated spring return valve actuated mechanically through a one way cam operating on the return stroke of swivel cylinder 80,

V8 is a 5-way mechanically actuated spring return valve actuated mechanically by sealer bear cylinder 87,

V9 is a 5-way solenoid actuated spring return valve actuated electrically by limit switch LS-5 which is in turn operated by a cam on shaft 103,

V10 is a 3-way air actuated spring return valve actuated pneumatically by air from V3,

V11 is a 5-way air actuated, air return valve actuated pneumatically by air from V1 and from V5,

V12 is a 5-way air actuated, air return valve actuated pneumatically by air from V2 and from V3 by intermediary of V7,

V13 is a 3-way air actuated spring return valve actuated pneumatically by air from V3 by'intermediary of V8,

V14 is a 5-way solenoid actuated air return valve actuated pneumatically by air from V5 and electrically by limit switch LS-l which is in turn operated by a cam on shaft 103,

V15 is a 5-way air actuated spring return valve actuated pneumatically by air from V5 by intermediary of V6 and V14,

V16 is a 5-way air actuated time delay solenoid return valve actuated pneumatically by air from V5 by intermediary of V6 and V14 and electrically through a time delay unit by limit switch LS4 which closes when sealer bars 83, 84 are closed,

V17 is a 3-way manually actuated spring return valve manually operated and serves to bypass V7. V17 is used in loading tape into the machine.

The five electrical limit switches operate as follows:

LS-l actuates momentarily at 180 rotation of crankshaft 103 (360 corresponds to the highest position of am 112, the beginning of the drawing action of draw roll 21),

LS-2 closes at 360 rotation and opens at 15 rotation of crankshaft, v

LS-3 opens when sealer bars 83, 84 are open, closing when sealer bars start to close. When LS-2 and LS-3 are both closed clutch 99 is disengaged and brake is engaged. This stops rotation of crankshaft 103,

LS-4 closes when sealer bars 83, 84 are closed,

LS 5 closes at and opens at 300 rotation of crankshaft 103.

The compressed air supply to the machine is controlled by an electrically operated valve actuated by the starter for electric motor 97.

Assuming that tape has been placed in the machine so that double plies of plastic coated tape are gripped by draw rolls 21 and 21A and tape for the loop handles is threaded through inching unit 24 and slots 25 the sequence of operation of the machine is as follows.

As motor 97 starts operating, crankshaft 103 passes through 360 and arm 112 moves downward rotating draw roll 21. At the same time limit switch LS-2 closes and if the sealer bars are closed closing LS-3, electric clutch 99 is disengaged and brake 110 engaged. The crankshaft is thus stopped until the sealer bars open, opening LS-3. Then clutch 99 is engaged and brake 110 disengaged causing rotation of the crankshaft to resume. At 15 rotation LS-2 opens also. Draw roll 21 continues to turn until the crankshaft reaches 180 when the direction of arm 112 is reversed. Due to the action of

unidirectional clutches

118 and 121 motion of draw roll 21 ceases.

During the period that the crankshaft is passing from 360 to 180 the pneumatically operated elements have been functioning. Valve V3 (FIG. 10) is in position to supply air to actuate valve V10 which in turn supplies air to inching cylinder 32. Inching unit 24 thus advances handle tapes through slots 25 and between the jaws of draw clamp 39. As the inching unit reaches the end of its traverse it actuates valve V1 mechanically. V1 supplies air to valve V11 which operates to feed air to draw clamp cylinder 46 closing the clamp jaws. As the jaws close a clamp projection actuates valve V2 mechanically. V2 supplies air to V12 actuating this valve to supply air to draw cylinder 48 thus drawing the two handle tapes across the handle insertion station and between the jaws of swivel clamps 54 and 55. When draw clamp 39 reaches the end of its-traverse it contacts a stop on control rod 50 pressing arm 52 against valve V3 actuatingit mechanically. V3 operates supplying air to V13 by intermediary of valve V8 which is in position to permit air passage, sealer bars 83 and 84 being open.

Valve V13 then operates supplying air to swivel clamp cylinders 65. and 66 closing the swivel clamp jaws upon the two lengths of'han'dle tape. As swivel clamp 54 closes jaw extension 60 actuates valve V4 mechanically. V4 operatesto supply air to actuate V5. V5 operates to supply air to V1 1 which operates to shut off the air supply to draw clamp cylinder 46, thus opening this clamp. V5 also supplies air by intermediary of V6 to shear cylinder 37. Shear 38 then operates cutting off the two lengths of handle tape. When shear 38 reaches the end of its stroke it actuates valve V6 mechanically redirecting air to V14. V14 however it not at this stage in position to pass air from V6.

When crankshaft 103 reaches the 180 position it actuates two limit switches LS-l and LS-S.

LS-5 actuates V9 electrically to supply air to cut off cylinder 137. Cut off knife 135 then operates to cut off a handle unit. When the crankshaft reaches the 300 position LS-S opens and valve V9 returns to its original position. This supplies air to cut off cylinder 137 to retract knife 135.

At 180 position of the crankshaft limit switch LS-l also is actuated, in turn actuating valve V14. V14 operates to direct air to V15 and V16.

V15 is actuated and supplies air to swivel cylinder 80 causing swivel clamps 54 and 55 to turn toward sealer bars 83 and 84 which are open. This places the ends of the two lengths of handle tape between sealer bars 83, 84 and above and below the length of plastic coated paper tape bying between the sealer bars.

V16 also is actuated, operating to supply air to sealer bar cylinder 87 and the cylinder of cooling unit 95. Sealer bars 83, 84 close sealing the ends of the looped handles to the plastic coated paper tapes. This position of the swivel clamps and sealer bars is illustrated in FIG. 8. At the same time the cooling unit bars 96 are compressing and cooling the handle seal of the previously fabricated handle unit. When the sealer bars start to close limit switch LS-3 closes causing clutch 99 to disengage and brake 110 to engage thus stopping the motion of draw roll 21. This stops motion of the plastic coated tape. 7

When the sealer bars close limit switch LS-4 also is closed. This actuates a preset timer which in turn actuates valve V16 to return it to its original position, this being conditional upon valve V14 also returning to its original position. V16 then will direct air to

cylinders

87 and 95 to open the sealer bars and the cooling bars of unit 95.

When the sealer bars 83, 84 close they contact V8 to actuate it mechanically. This disconnects the air supply to valve V13 permitting this valve to return to its original position. This causes swivel clamps 54, 55 to V5 then returns to its original position and supplies air to actuate valves V6 and V14 returning these valves to their original positions. V6 is thus again in position to relay air from V5 to shear cylinder 37. The original position of V14 disconnects actuating air. from valves V15 and V16 permitting these valves to return to their original positions.

When V16 returns to its original position this directs air to cylinders 87 and to open the sealer bars and the cooling bars. This causes limit switch LS-3 to open starting motion of draw rolls 21, 21A. This draws the newly sealed handle unit from between thesealer bars and places it between the cooler bars, the motion continuing until the crankshaft reaches the 180 position.

When V15 returns to its original position it directs air to swivel cylinder 80 to return the swivel to its original position. The action actuates cam operated valve .V7 opening this valve to supply actuating air to valve V12. This causes V12 to return to its original position thus supplying air to draw cylinder 48. This returns draw clamp 39 to its original position adjacent to inching unit 24. This action causes control rod arm 51 to return valve V3 to its original position. This directs air to V10 to operate the cylinder 32 'of the inching unit. The sequence of operations then will repeat.

lt can be seen that the operation of draw rolls 21, 22 and operation of the swivel mechanism and sealer bars are co-ordinated so that the handle sealing operation -can take place only when the draw rolls are at rest.

It is clear that the handle sealing station can be used to seal handles directly to the mouths of plastic bags. This can be done by provision of wider guides 20 and draw rolls 21, 21A in order to handle folded two ply strips of plastic bag material.

The handle units provided by the machine of this invention are illustrated in FIG. 9. They consist of a length of plastic coated paper to which a loop handle 141 is heat-sealed. These handle units are readily heat-sealed to the mouths of plastic bags. The method of fabricating such a carrying bag is shown in FIG. 11. A folded length of heat-scalable plastic. film is formed having front panel 142 and back panel 143 joined by gusseted bottom panel 144. The edges of the film are unsealed. Two handle units with plastic coating sides facing outward are placed between the open ends of the folded length of film. With standard heat-sealing methods the handle units are then sealed to the ends of the folded film. The side seams of the bag are then formed including the longitudinal seams 145 and diagonal gusset seams 146. The completed carrying bag is shown in FIG. 12.

The apparatus of this invention provides a means for attaching automatically handles to carrying bags, thus minimizing the number of manual operations in the manufacture of carrying bags.

What we claim is:

1. A machine for attaching handles to carrying bags comprising in combination 1. means for providing a predetermined length of a first strip of heat-sealable material,

2. two co-operating heat-sealing members,

l060ll 0255 3. means for positioning the first strip in rectilinear configuration between the two heat-sealing members,

4. means for providing a predetermined length of a second strip of heat-scalable material,

6. two swivel clamps located adjacent to the heatsealing members and adapted to clamp the second strip in rectilinear configuration at positions distant from the strip extremities by an amount sufficient to provide a portion of strip for heatsealing to the border of the first strip,

. means for compressing the heat-sealing members together, thus heat-sealing the two ends of the second strip to the border of the first strip, the second strip being in loop form,

9. means for withdrawing the sealed-together strips from between the heat-sealing members and 10. means for cutting the first strip carrying the loop of second strip to desired length.

2. A machine as claimed in claim 1 wherein means is provided for cooling the seal area of the sealedtogether strips.

3. A machine as claimed in claim 1 wherein the means for providing the predetermined length of the first strip of material comprises two draw rolls operating intermittently for a predetermined amount of rotation.

4. A machine as claimed in claim 1 wherein the means for providing the predetermined length of the second strip of material comprises a clamp having a pneumatically operated jaw for gripping the end of the strip, the clamp being mounted on a guide and adapted to traverse a predetermined distance along said guide.

5. A machine as claimed in claim 1 wherein the means for swivelling the swivel clamps in mutually reverse directions comprises two intermeshing sector gears, a gear being fixed to each clamp.

6. A machine as claimed in claim 1 wherein the operation of the elements of the machine is controlled by an electrical-pneumatic control system.

l060ll 0256

Claims

1. A machine for attaching handles to carrying bags comprising in combination 1. means for providing a predetermined length of a first strip of heat-sealable material, 2. two co-operating heat-sealing members, 3. means for positioning the first strip in rectilinear configuration between the two heat-sealing members, 4. means for providing a predetermined lengTh of a second strip of heat-sealable material, 5. means for holding the second strip in rectilinear configuration parallel to but separated from the first strip, 6. two swivel clamps located adjacent to the heat-sealing members and adapted to clamp the second strip in rectilinear configuration at positions distant from the strip extremities by an amount sufficient to provide a portion of strip for heatsealing to the border of the first strip, 7. means for swivelling the swivel clamps in mutually reverse directions in such sense as to place the two ends of the second strip between the heat-sealing members and adjacent to the border of the first strip positioned therebetween, 8. means for compressing the heat-sealing members together, thus heat-sealing the two ends of the second strip to the border of the first strip, the second strip being in loop form, 9. means for withdrawing the sealed-together strips from between the heat-sealing members and 10. means for cutting the first strip carrying the loop of second strip to desired length.

2. two co-operating heat-sealing members,

2. A machine as claimed in claim 1 wherein means is provided for cooling the seal area of the sealed-together strips.

6. two swivel clamps located adjacent to the heat-sealing members and adapted to clamp the second strip in rectilinear configuration at positions distant from the strip extremities by an amount sufficient to provide a portion of strip for heat-sealing to the border of the first strip,

8. means for compressing the heat-sealing members together, thus heat-sealing the two ends of the second strip to the border of the first strip, the second strip being in loop form,

9. means for withdrawing the sealed-together strips from between the heat-sealing members and