US3577300A - Bag folding and sealing apparatus - Google Patents

Abstract

A SHAFT DRIVEN BY A SINGLE REVOLUTION CLUTCH OPERATES (A) A MECHANISM FOR FOLDING A CLOSURE FLAP AGAINST THE BODY OF A BAG (B) A MECHANISM FOR HEAT SEALING THE FLAP TO THE BAG, AND (C) A CONVEYING MECHANISM FOR EJECTING THE SEALED BAG FROM THE APPARATUS. A MOVABLE STOP ACTUATED BY THE SHAFT SERVES AS A GUIDE FOR PROPERLY LOCATING A BAG IN THE APPARATUS, AND THE STOP IS RETRACTED AFTER A FLAP IS FOLDED TO PERMIT EJECTION OF THE BAG BY THE CONVEYING MECHANISM. THE FLAP FOLDING MECHANISM INCLUDES A PIVOTED FLAP FOLDING PLATE WHICH HAS SPACED APART OPENINGS PERMITTING ACCESS OF A SERIES OF SIMILARLY SPACED APART HEAT SEALING ELEMENTS TO A FOLDED BUT UNSEALED FLAP.

Description

y 1971 J. w. GLAZE. JR.. ETA!- 3,577,300

I BAG FOLDING AND SEALING APPARATUS 1 'Filed Dec; 1. 1969 A 3 Sheets-Sheet 1 MICRO A SWITCH OFF ONE REVOLUTION V I CLUTCH J l FLAP 610550 A P FOLDER OPEN J HEAT SEALS SEALER up "5" DOWN PACKAGE l lP A "WENTORS JoHNvAGLAzE JR. GU'DE WN L JOSEPHP. wo'nm EJECTING m mum- E mm mm; BY 9% ROLLER our or ENGAGEMENT wrrH ibeym PACKAGE I j ATTORNEYS y 7 J. W. GLA ZE, JR.. ET/M-iv I 3,

BAQ FOLDING AND SEALING APPARATUS Filed necg g 1969 T s Sheets-Sheet FICLZ May 4, 1971 J. w. GLAZE. JR.. ETAL 3,577,300.

A BAG FOLDING AND SEALING APPARATUS 7 Filed Dec. ,1, 1969 3 Sheets- Sheet s Uzi till? m! 1 v INVENTORS JOHN w GLAZE JR, 50 JOSEPH P. WORTH I 8 Q 4' .'D2

. 59 62 moamzvs United States Patent Oflice 3,577,300 Patented May 4, 1971 Int. Cl. B43m 5/04 US. Cl. 156-4415 20 Claims ABSTRACT OF THE DISCLOSURE A shaft driven by a single revolution clutch operates (a) a mechanism for folding a closure flap against the body of a bag, (b) a mechanism for heat sealing the flap to the bag, and (c) a conveying mechanism for ejecting the sealed bag from the apparatus. A movable stop actuated by the shaft serves as a guide for properly locating a bag in the apparatus, and the stop is retracted after a flap is folded to permit ejection of the bag by the conveying mechanism.

The flap folding mechanism includes a pivoted flap folding plate which has spaced apart openings permitting access of a series of similarly spaced apart heat sealing elements to a folded but unsealed flap.

This is a continuation-in-part of copending application Ser. No. 604,016, filed Dec. 22, 1966, entitled Hosiery Machine. The disclosure of the foregoing application is incorporated by reference herein, in its entirety, with particular attention being directed to the flap folding and sealing apparatus shown in FIGS. 28-33 thereof.

This invention is directed to apparatus for folding a closure flap portion of a bag against the body of the bag, and then sealing the flap to the bag, preferably by the use of heat which activates a temperature-responsive adhesive or autogenously bonds a thermoplastic flap to the body portion of the thermoplastic bag. The flap may be of various types. For example, it may be a single thickness extension of one face of the bag, or it may be formed by overfolding the entire end portion of a bag having coextensive faces.

In the past, it has frequently been the practice to fold the flap of a bag manually and then seal the flap to the bag either with a hand-held heating implement or by inserting the bag in a sealing machine. Some machines have had the ability both to fold and to seal the flap; however, these prior machines have not used the unique and efiicient manner of constructing and operating the various elements thereof, nor have they employed the particular type of folding plate and sealing element which characterize the machines disclosed in this specification and in the aforementioned copending application.

One object of the invention is to provide a novel pivoted flap folding member having spaced apart openings which cooperates with a heat sealing head having spaced apart sealing elements so that the sealing elements will extend through the openings in the flap folding member in order to effect a satisfactory sea].

A further object of the invention is to simplify the construction of closure flap folding and sealing apparatus by using a common drive shaft to operate the flap folding and flap sealing means. Furthermore, the same common drive means may operate a bag-ejecting conveyor and it may operate a guide member which initially positions the bag in the apparatus.

A further object of the invention is to provide a simple and useful means for ejecting sealed bags from the apparatus by employing a conveyor which rotates throughout the machine cycle yet is configured to engage a bag frictionally only after a flap is sealed to its associated bag.

A movable guide means for initially positioning an unfolded and unsealed bag in the apparatus is retracted from its operative position to permit a bag to be ejected by the apparatus. The conveyor and the guide means are conveniently and preferably operated by the same shaft which actuated the flap folding means and the flap sealing means.

Another object is to provide a novel combination which includes a flap folding mechanism and a bag-guiding element, wherein the operation of the folding mechanism serves to move the bag against the bag guiding element when there is an initial misalignment between the bag and the guiding element. This movement of the bag orients it properly for a subsequent bag sealing operation.

Other objects will be appreciated by those working in this art who become familiar with the machine disclosed in this specification.

One invention embodied in the disclosed apparatus involves the construction of the flap folding and sealing elements, wherein a pivoted flap folding member has a plurality of spaced apart openings. The sealer head has a plurality of spaced apart sealing elements which pass through the openings in the flap folding member to seal the flap in position while it is held by the flap folding member.

According to another aspect of the invention, the construction of a flap folding and sealing apparatus is simplified by using a common drive shaft which operates a flap folding means and a sealing means. The flap folding means is a pivoted plate which engages a flap and holds it in position during the operation of the sealing means.

Another concept utilized in the disclosed apparatus pertains to the manner in which a conveyor operates to eject a bag from the folding and sealing station. The bag is frictionally engaged by a radially enlarged portion of a conveying roller which rotates throughout the machine cycle, including the time when the folding and sealing means are in operation.

During the operation of the folding means, a bagpositioning guide contacts the end of the bag which is remote from the flap so that operation of the folding means will move the bag to correct for small misalignment between the bag and the stop. Upon completion of the sealing step, the guide is retracted to permit the radially enlarged portion of the conveyor roller to eject a sealed bag from the apparatus.

Preferred forms of apparatus embodying some or all of these inventive concepts are disclosed in the aforementioned pending application Ser. No. 604,016 and in the accompanying drawings wherein FIG. 1 is a perspective view of the apparatus, enclosed in its housing, together with a bag having an open and unsealed flap.

FIG. 1A shows the flap end of the bag of FIG. 1, with the flap folded and sealed.

FIG. 2 is a front elevation, partially in section, showing some of the operative elements of the apparatus.

FIG. 3 is a left side elevation of the apparatus with the housing removed.

FIG. 4 is a view taken along the line 4-4 in 'FIG. 2 and disclosing the mechanism for operating the flap folding and sealing means.

FIG. 5 is a view of the cam mechanism for actuating the flap sealing means.

FIG. 6 is a view taken along the line 6-6 in FIG. 2, showing the mechanism for moving the bag-positioning guide member.

FIG. 7 is a view taken along the line 7-7 in FIG. 6, showing the details of construction of the flap folding member and the sealer backup member; and

FIG. 8 is a time diagram showing the sequential operation of the principal elements of the apparatus during one machine cycle.

The flap folding and sealing machine shown in FIG. 1 is constructed to receive manually fed bags. The bags 2 may be formed by peripherally sealing a pair of face-toface thermoplastic sheets around the side and bottom edges, with the upper end of one sheet extending outwardly beyond the upper edge of the other sheet, thereby creating the flap portion 4 which is adapted to be folded along the fold line AA against the main body portion 6 of the bag.

The bag 2 preferably encloses a card-board insert or an article which gives dimensional stability to the main body portion 6. It is manually placed in the apparatus by inserting the upper portion of the bag between the converging guide lips 8 and placing the remainder of the bag on the supporting surface 10 at a position where the bottom edge of the bag will abut the bag-positioning guide plate 12. Inclined guide surfaces 14 and 16 facilitate movement of the bag onto the supporting surface 10.

Proper placement of the bag. on the surface 10 will close a microswitch having an exposed actuator 18 to initiate a cycle of the machine. During one machine cycle, the flap portion 4 is overfolded about the fold line AA into facing relationship with the body of the bag as shown in FIG. 1A. While held in this folded position, the flap 4 is sealed to the body of the bag at a series of spacedapart spots such as those designated 32 in FIG. 1A. Upon completion of the sealing step, the stop member 12 is automatically lowered to expose the bottom edge of the bag and the bag is ejected from the apparatus by the ejecting conveyor roller 22. A control panel 24 on the apparatus includes an on-olf switch 26, an indicator light 28 which is illuminated when the switch 26 is closed, and a thermostatic regulator knob 30 for the sealing head.

The flap folding mechanism is seen in FIGS. 4, 6 and 7. The portions of this mechanism which operate upon the bag are the folder backup plate 47 and the flap folding member 49, both of which are best shown in FIG. 7. The backup plate 47 is stationary and forms a portion of the bag-supporting surface. The flap folding plate 49 is pivotally movable through an arc of 180 about the pivot axis defined by the pivot pins 50 and 52 which are located at its opposite ends.

The flap folding member 49 is oriented in the position shown in FIGS. 4, 6 and 7 when a bag is placed in the apparatus. The bag is positioned by the guide member 12 so that its flap will lie on the plate and the pivot axis of the flap folding member 49 will be parallel and proximate to the intended fold line of the bag. Folding takes place by movement of the flap folding member 49 through an arc of approximately 180 to bring it into parallel facing relation to the backup plate 47, with the folded flap and a portion of the bag body located between the elements 47 and 49.

While the flap is held in its folded position by the member 49, a sealer head 56 is moved downwardly into contact with the flap, in order to seal the flap to the body portion of the bag. As shown in FIG. 2, the sealer head 56 has a series of depending sealing elements 58 adapted to perform the sealing operation. The sealing elements '58 are spaced apart and located where they will pass through the openings 54 in the flap folding member 49. Preferably, the sealer head 56 includes a single heating element extending longitudinally therewithin to generate the heat necessary to activate a heatsensitive adhesive or to soften the plastic of a bag for autogenous bonding.

Upon completion of the sealing step, the sealer head 56 is moved upwardly to its inoperative or retracted position and flap folding member 49 is returned to the position shown in FIGS. 4, 6 and 7. The bag-positioning guide 12 is retracted to the position shown in broken lines in FIG. 6, thereby permitting discharge of the bag by the radially enlarged area of conveyor roller 22.

The preferred construction of the elements which operate the flap folder and sealing head are shown in 4 FIGS. 2-7. All of these elements are operated by a common source of motive power connected to a common drive shaft. The source of power is the electric motor 34 which is turned on and off by the switch 26. As shown in FIG. 3, the motor 34 carries an output sprocket 36 connected by a chain 38 to a sprocket 40 which is connected to a shaft 44. The motor 34 operates 'whenever the switch 26 is closed to provide continuous rotation of the sprockets 36 and 40 and the shaft 44.

As will be seen from FIG. 2, the shaft 42 drives a single revolution clutch 46 which may be of any known type. The output shaft 48 from the single revolution clutch 46 carries cams which operate the flap folder, flap sealer and bag guide elements. The shaft 48 also directly drives the ejecting conveyor roller 22.

The single revolution clutch 46 is normally disengaged so the machine performs no folding or sealing functions. However, when the side edge of a bag is pressed against the switch actuator 18 shown in FIG. 1, the clutch 46 engages to rotate the shaft 48 only one revolution. Upon completion of one revolution, the clutch 46 automtaically disengages and remains in this condition until the microswitch actuator 18 is again depressed.

As seen in FIG. 4, the flap folder 49 is moved through its arcuate path by rotation of a spur gear 57 which meshes with a larger spur gear 59. Gear 57 is keyed to the shaft 50 which, in turn, is rigidly connected to the flap folder member 49.

Rotation of the spur gear 59 is initiated by axial movement of the folder actuating rod 62 which has one end pivotally connected to a fastener 64 on the gear 59, and its other end pivotally connected at 68 to the lever arm 70. The rod 62 has an adjustable length in order to permit fine adjustments in the operation of the apparatus.

The movement of the folder lever arm 70 is produced by rotation of the main drive shaft 48 which carries the folder actuating cam 72 shown in FIG. 5. The lever arm 70 is pivoted about a rod 76 and it carries a rotatable cam follower 74. A spring maintains the cam follower against the cam. As the shaft 48 rotates, the cam follower 74 moves from the circular surface 78 onto the inclined surface 80 which swings the lever arm 70 in a counterclockwise direction as viewed in FIG. 4. This moves the rod 62 to the right, rotates the gear 59 in a counterclockwise direction, and rotates the gear 57 in a clockwise direction to move the flap folder 49 about its pivot axis in a clockwise direction. When the cam follower 74 rides along the enlarged circular surface 82 on the cam 72, the flap folder will dwell in its folding position where it faces the backup plate 47. During this dwell interval, the flap is sealed to the bag body. Upon completion of the sealing step, continued rotation of the cam 72 results in movement of the cam follower on the downhill surface 84 of the cam to return the flap holder member 49 to the position shown in FIG. 4.

The sealer head 56 is supported by rods 86 and brackets 88 which are connected to a pivot rod 90. Also connected to the pivot rod is a lever 92. The pivot rod 90 is pivotally mounted in a stationary extension 94 so that movement of the lever 92 will result in swinging move ment of the sealer head 56 about the axis of the pivot rod 90. This swinging movement is created by axial movement of the sealer actuating rod 96 which has its opposite ends pivotally connected to a fastener 98 on the lever 92 and to a pivot member 100 aifixed to the sealer actuating lever 102. The sealer actuating lever 102, like the folder actuating lever 70, is pivotally mounted on the stationary rod 76.

As shown in FIG. 5, the sealer actuating lever 102 is biased by a spring 104 for movement in a clockwise direction. A roller cam follower 106 on lever 102 rides on the sealer cam 108 to limit this clockwise movement. As the cam follower 106 rides on the circular portion 110 of the cam 108, there is no movement of the sealer actuating rod 96 and it remains in its elevated position.

However, during the time period when the flap folder dwells in the position where it holds the flap in a folded condition, the cam follower 106 arrives at the depressed face 112 of the cam 108. This produces clockwise movement of the sealer actuating lever 102 and clockwise movement of the elements 86, 88, 92 and the sealer head 56. This moves the sealer head 56 downwardly so that its sealing elements 58 will pass through the openings 54 in the flap folding plate 49, thereby sealing the flap to the bag in the areas shown at 32 in FIG. 1A and in broken lines in FIG. 7.

As previously mentioned, the sealed bag is ejected from the apparatus by the ejecting conveyor roller 22 which is affixed to the main drive shaft 48 for rotation therewith. The configuration of this roller is best seen in the broken line representation thereof in FIG. 6. It has an exaggerated radius in the area which will be uppermost upon completion of the sealing step. This will cause the roller 22 to project above the bag supporting surface after the sealing step, enabling it to frictionally engage with the bag and eject it from the apparatus. In order to ensure proper alignment of the bag in the apparatus for the sealing step, the bag guide 12 projects above the surface 10 during the folding and sealing operations. If there is a slight initial misalignment between the bottom edge of the bag and the stop 12, the operation of the folding member 49 will displace the bag into its proper position against the stop 12. However, upon completion of the sealing operation, the guide 12 is dropped by the mechanism shown in FIG. 6 to the position shown in broken lines in FIG. 6. The stop 12 is supported on a rod 114 which is connected to a lever 116. The lever 116 is pivotally mounted about the previously mentioned rod 76, and it carries a cam-following roller 118 which rides along the face of the guide-operating cam 120. During the folding and sealing operations, the cam roller 118 rides along the enlarged surface 122 of the cam so the guide 12 remains in the position shown in solid lines in FIG. 6. However, upon completion of the sealing step, the cam follower moves downwardly along the surface 124 and onto the reduced radius surface 126 of the cam 120. When the roller 118 is on the surface 126, the bag guide 12 will move to the position shown in broken lines in FIG. 6 where it rests against a rubber bumper 128. With the guide 12 in its lowered position, the ejecting roller 22 will be capable of conveying the sealed bag from the apparatus.

The bag stop 12 is attached to the rod 114 'by a setscrew 115. When bags having different dimensions are used in the apparatus, the setscrew 115 may be released and the bag stop 12 axially adjusted along the rod 114 to the appropriate position.

The sequence of operation of this apparatus may be visualized by referring to the time sequence diagram of FIG. 8. At all times, the motor 34 is running to drive the input sprocket 40 on the single revolution clutch 46. When an operator places a bag in the apparatus where it lies on the support surface 10 and closes the microswitch 18, the single revolution clutch 46 is engaged to initiate one revolution of the main drive shaft 48. Initially the revolution of the shaft 48 will move the flap folding member 49 through an arc of approximately 180 to fold the flap against the body of the bag. The flap folder 49 is held over the folded flap in the bag as the sealer head 56 is moved downwardly to pass between the openings 54 in the folder member and seal the bag at the locations designated 32 in FIGS. 1A and 7. The sealer head is raised to its retracted position and the folder member 49 returns to its FIG. 7 position. While this is taking place, the package stop 12 is lowered and the radially enlarged portion of the bag ejecting conveyor 22 engages the undersurface of the bag to discharge it from the apparatus.

From the foregoing description, it will be appreciated vention represent a forward step in the field of folding and sealing bags. The inventive features thereof, as set forth in the following claims, are of course capable of inclusion in numerous other types of bag folding and sealing machines.

What is claimed is:

1. Apparatus for folding a flap portion of a bag along a fold line and then sealing the flap portion to the body portion of the bag, comprising,

means for supporting the bag in a given position, said supporting means including a sealer backup member located on one side of the fold line, a flap folding member located on the other side of the fold line having a flap-confronting face which lies against a flap portion of the bag when the bag is in said given position, said flap folding member having a plurality of spaced apart openings and being pivoted about an axis which lies parallel and proximate to said fold line,

means for moving said flap folding member about its pivot axis from an initial position where its flap-confronting face is spaced from said sealer backup member to a flap holding position where it is in parallel face-to-face relation to said sealer backup member to hold an overfolded flap against the body portion of a bag,

a sealer head having a plurality of spaced apart sealing elements, means for moving said sealer head from a retracted position to an operative position where said sealing elements extend through the openings in said flap folding member to seal the flap -to the body portion of the bag.

2. Apparatus accord-ing to claim 1 for sealing bags by the application of heat wherein said sealer head includes means for heating said sealing elements.

3. Apparatus according to claim 1 having an open passage permitting movement of a bag into the apparatus in a direction parallel to the pivot axis of the flap folding member.

4. Apparatus according to claim 3 having converging guide means leading toward said flap folding member and said sealer backup member to facilitate introduction of a bag into the apparatus in a direction parallel to the pivot axis of the flap folding member.

5. Apparatus according to claim 1 having conveyor means for ejecting a bag from the apparatus.

6. Apparatus according to claim 5 wherein the conveyor means moves a sealed bag in a direction perpendicular to the pivot axis of the flap folding member.

7. Apparatus according to claim 1 wherein the means for moving said flap folding member about its pivot axis includes a driven spur gear connected to the flap folding member for rotational movement therewith, a driving spur gear engaged with the said driven spur gear, a connecting rod pivotally attached to said driving spur gear, and cam means for axially moving said rod to produce rotational movement of said driving spur gear.

8. Apparatus according to claim 1 having a rotatable drive shaft which carries a first cam means for actuating the means for moving said flap folding member and a second cam means for actuating the means for moving said sealer head.

9. Apparatus according to claim 8 having a bag ejecting conveyor connected to said drive shaft and constructed to eject a bag from the apparatus upon movement of the sealer head from its operative position.

10. Apparatus according to claim 9 wherein the bag ejecting conveyor is a roller, said drive shaft being connected to and rotatable with said roller, said roller having a radially enlarged area for frictionally contacting a bag only after movement of the sealer head to its operative position.

:11. Apparatus for folding a flap portion of a bag along a fold line and then sealing the flap portion to the body of that the disclosed and preferred embodiments of the ina bag, comprising,

bag supporting means having an aperture,

flap folding means for folding a flap against the body portion of the bag, sealing means for sealing a flap folded by said flap folding means to the body portion of a bag,

conveying means for ejecting a sealed bag from the apparatus upon completion of the operation of said sealing means,

said conveying means having a conveying roller aligned with the aperture in the bag supporting means, means for rotating said conveying roller during and after the operation of said flap folding means and said sealing means, said conveying roller having an area of reduced radius facing said aperture and lying below the bag supporting means during operation of said flap folding means and said sealing means and an area of enlarged radius which will project upwardly through the aperture after operation of the sealing means to frictionally engage a sealed bag and eject it from the apparatus.

12. Apparatus according to claim 11 having a drive motor for said conveying roller, and a single revolution clutch having its input end connected to said drive motor and its output end connected to and rotatable at a same angular velocity with said drive motor and said conveying roller.

13. Apparatus according to claim 11 having a common drive shaft operatively connected to said flap folding means, said sealing means and said conveying means.

14. Apparatus according to claim 13 having a continuously operating drive motor and a single revolution clutch interposed in the drive train from the drive motor to the common drive shaft.

15. Apparatus according to claim 14 having means for actuating said single revolution clutch in response to placement of an unsealed bag in the apparatus.

16. Apparatus for folding a flap portion of a bag along a fold line and then sealing the flap portion to the body of a bag, comprising,

means providing a bag supporting surface,

flap folding means for folding a flap along a fold line against the body of the bag,

sealing means for sealing a flap folded by said flap folding means to the body of a bag,

bag-positioning guide means having an operative position where it intersects and extends above the plane of the bag supporting surface for initially establishing the position of an unsealed bag in the apparatus by contacting the bag at its end remote from the flap portion, and means for retracting said guide means from the plane of said bag supporting surface after the operation of said flap folding means to permit removal of a sealed bag parallel to said bag supporting surface and in the direction of said guide means.

17. Apparatus according to claim 16 having means operative after retraction of the guide means for conveying a sealed bag parallel to said bag supporting surface and in the direction of the operative position of said guide means after operation of said sealing means.

18. Apparatus according to claim 16 wherein the flap folding means folds the flap in a direction toward the guide means; whereby the operation of the flap folding means will urge the bag against the guide means to correct for initial misalignment between the bag and the guide means.

19. Apparatus for folding a flap portion of a bag along a fold line and then sealing the flap portion to the body of a bag, comprising,

flap folding means for folding a flap against the body portion of the bag,

Sealing means for sealing a flap folded by said flap folding means to the body portion of a bag,

drive means including a common drive shaft for moving said flap folding means and said sealing means a conveyor roller means connected to and rotatable with the common drive shaft, said conveyor roller being operative to eject a sealed bag from the apparatus after operation of said sealing means,

guide means for positioning an unsealed bag in the apparatus by contacting the bag at its end remote from the flap portion, and

means operable by said common drive shaft for retracting said guide means to an inoperative position after the operation of said flap folding means.

20. Apparatus for folding a flap portion of the bag along a fold line and then sealing the flap portion to the body of a bag, comprising,

flap folding means for folding a flap against the body portion of the bag,

sealing means for sealing a flap folded by said flap folding means to the body portion of a bag,

drive means including a common drive shaft for moving said flap folding means and said sealing means, and

a conveyor roller means connected to and rotatable with the common drive shaft, said conveyor roller being operative to eject a sealed bag from the apparatus after operation of said sealing means, said conveyor roller having a radially enlarged area oriented to frictionally contact a bag only after operation of said sealing means.

References Cited UNITED STATES PATENTS 1,153,325 9/1915 McDade 156-442 1,708,534 4/1929 Christman, Jr 2706l 2,158,144 5/1939 Oskow 27061 FOREIGN PATENTS 251,547 11/1911 Germany 156-4415 BENJAMIN A. BORCHELT, Primary Examiner G. E. MONTONE, Assistant Examiner US. Cl. X.R.

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