US2494176A

US2494176A - Adhesive applying mechanism

Info

Publication number: US2494176A
Application number: US770125A
Authority: US
Inventors: Stanley R Howard
Original assignee: Pneumatic Scale Corp
Current assignee: Pneumatic Scale Corp
Priority date: 1947-08-22
Filing date: 1947-08-22
Publication date: 1950-01-10
Anticipated expiration: 1967-01-10

Description

Jan. l0, i950 s. R. HOWARD 2,494,176

ADHESIVE APPLYING MECHANISM Filed Aug. 22, 1947 2 sheets-sheet 1 16.) l l Ri .2

|'"Z` INVENTOR. Jn/y fowqrq/ e2) BY JM @Amm ATTORNEY Jan. l0, 1950 s. R. HOWARD 2,494,176

ADHESIVE APPLHNG MECHANsM Filed Aug. 22,' 1947 2 Sheets-Sheet 2 IN VEN TOR.

BYv

JM cme@ H TTOENEF Patented dan. 1 0, 1950 ADHESIVE APPLYING MECHANISM Stanley R. Howard, Milton, Mass., assignor to Pneumatic Scale Corporation, Limited, Quincy, Mass., a corporation of Massachusetts Appiication August z2, 1947, sel-iai No. 770,125

4 Claims. l

This invention relates to a packaging machine and particularly to adhesive applying mechanism for a packaging machine.

The invention has for an object to provide novel and improved adhesive applying mechanism for applying a uniform film of a viscous adhesive to a continuously moving web in a novel and superior manner.

With this general object in view, and such others as may hereinafter appear, the invention consists in the adhesive applying mechanism and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention, Fig. l is a side elevation of a portion of a packaging machine embodying the present invention; Fig. 2 is a plan view of a portion of a web of bag forming material to which stripes of adhesive have been applied to the seam forming portions of the connected blank sections thereof; Fig. 3 is a perspective view of the mechanism shown in Fig. 1; Fig. 4 is a diagrammatic side elevation illustrating the adhesive applying mechanism, embodying an additional adhesive applying device fora purpose to be described; Fig. 5 is a side elevation of a modified form of an adhesive applying mechanism embodying the invention; and, Fig. 6 is a perspective view of the lining bag produced by the present packaging machine.

In general, the present invention contemplates a packaging machine embodying an improved adhesive applying mechanism particularly adapted for the application of viscous adhesives such as the non-drying tacky adhesives which are used in the production of Scotch tape often referred to as pressure sensitive. adhesives, or the so-called` high melt heat sealing adhesives, both of which are preferably applied in a heated condition. vIn practice, it has been found that a viscous adhesive cannot be successfully applied in a conventional manner to a continuously moving web of bag forming material to apply a uniform iilm of adhesive thereon because of the tendency of the viscous adhesive to string out preventing the uniform application thereof.

In accordance with the present invention, the continuously moving web of bag forming material traveling in one direction is arranged to be pressed against an adhesive supply roller rotating in a direction opposite to the direction of travel of the web whereby to provide a wiping action capable of applying a uniform lm of a viscous adhesive to the web without smearing. Provision is also made for controlling the amount of adhesive transferred to the web byA limiting the movement of the web against the supply roller whereby to maintain a uniform thickness of the lm of adhesive transferred. Provision is also preferably made for simultaneously applying a plurality of stripes of adhesive to the web in the manner described. For example, for some purposes one set of stripes may comprise pressure sensitive adhesive, a second set of stripes a high melt adhesive, and a third set of stripes a heat sealing adhesive.

Referring now to the drawings, the present invention comprises in general a noval and improved adhesive applying mechanism, indicated generally at III, for applying adhesive to one 0r more portions of a continuously moving web I2, and in the preferred form, as herein shown, is embodied in a packaging machine indicated generally at I4 of the type having an intermittently rotated spider provided with a plurality of horizontally and radially extended forming blocks or mandrels I6 only one of which is shown and about which blanks I8 of bag forming material, severed from the web I2, are wrapped to produce a lining bag 20, as shown in Fig. 6. Such packaging machines may comprise any usual or preferred form now upon the market, such for example as the machine illustrated in the United States patent to Hesser, N o. 1,020,821, issued March 19, 1912.

Such machines are designed `to produce a composite container which comprises an inner lining bag first formed upon the'forming block and an outer carton formed over the lining bag while the latter is still retained upon the forming block and only a suiiicient portion of the packaging machine has been illustrated as will enable the present invention to be understood.

In the illustrated embodiment of the invention provision is made for applying. longitudinal stripes 22 of adhesive along a marginal edge of the continuously moving bag forming web I2, the stripes being interrupted at the line of severance 24 of successive blanks I8, and, provision is also made for applying

stripes

26, 28 of adhesive along spaced transverse portions of the continuously moving web I2, the longitudin-al stripe 22 being disposed to form the side seam 30 of the lining bag 20 and the

transverse stripes

28, 26 being disposed to form the top and bottom closures respectively of the lining bag or other container.

As herein shown, the web I2 of bag forming material is unwound from a supply roll 36 thereof by a pair of driven

feed rollers

38, 40 arranged to continuously advance the web at a rate such as to dispose the web in operative position to a cutter 42 each cycle of operation to sever the web along the lines 24 to provide successive blanks I8 which may then be advanced into operative position to successive forming blocks I6 about which the blanks are wrapped to form the lining bags. The

feed rollers

38, 40 may and preferably will be driven in timed relation to the operation of the packaging machine through a chain and sprocket drive, indicated at 44, connected to a drive shaft 46 having a pinion 48 fast thereon. The pinion 48 is arranged to mesh with a gear 50 fast on the lower feed roll shaft 52 and the gear 58 is arranged to cooperate with a gear 54 fast on the upper feed roll shaft 56. As illustrated in Fig. 1, the web I2 being unwound from the supply roll 36% first passes around a guide roller 58, then upwardly over a roller 80 forming a part of the adhesive applying meehanism, indicated generally at 82, for applying the

transverse stripes

28, 28 of adhesiveto the web, and then over a roller 8l forming a part of the adhesive applying mechanism, indicated generally at 86, for applyingthe longitudinal stripes 22 of adhesive to the web, whereupon the web passes betweenv the continuously driven

feed rollers

38, 40. As best shown in Fig. 3, the upper feed roller 38 is provided with spaced cut-outs 51, 59 arranged to register with the

transverse stripes

28, 28 in order to permit the web to pass between the feed rollers, and, a grooved cut-out 6| 'is also provided to avoid the longitudinal stripes 22. In accordance with the present invention the

rollers

80, 84 are arranged to guide the web adjacent their respective adhesive applying rollers 90, 92 and to press the web into engagement withthe applying rollers to effect transfer of adhesive to the web, the applying rollers being driven ln'a direction opposite to the direction of travel of the web. As herein shown, the adhesive applying rollers 90, 92 are arranged to 'be driven from the drive shaft 46 through a chain and sprocket drive including a chain 94 arranged to pass over a sprocket 96 fast on the shaft 48, then over 4an idler sprocket 9s for eifecting rotation in the opposite direction, and then over sprockets |00, |02 fast on adhesive applying roller shafts |04, |06 respectively.

The guide roller 5l is arranged to provide a slight tension in the web I2 to effect unwinding from the supply roll 38 during the continuons advancement of the web, and also to maintain the web in a relatively taut condition between the guide roller 58 and the

feed rollers

38, 40 during the movement of the

presser rollers

80, 84 toward and from the applying rollers 90, 92 in the operation of the device. As herein shown, the guide roller 53 is carried by one arm 60 of a bell-crank pivotally mounted at 62, the

other arm I4 being connected to a spring 66 for urging the bell-crank in a clockwise or web un- Nwinding direction viewing Fig. 1.

In practice, the spring i6 is designed to permit the guide roller 88 to yield slightly upon movement of the presser rollers 80, toward their respective applying rollers and also to effect a substantially continuous unwinding strain on the web, the spring being preferably made relatively weak so as to prevent an undue strain and consequent tearing of the paper web. In those instances where the continuous web unwinding strain imposed upon the roller 58 is abnormal or sumcient to overcome the force of the spring 88, so that the bell-crank is caused to turn counter-clockwise from its normal operating position 4 shown in Fig. 1, a cam operated mechanism may be provided to unwind material from the roll 36 by positively moving the bell-crank clockwise to return it to substantially the position as illustrated in Fig. l, during each cycle of operation and preferably during the time in the cycle when the

presser rollers

80, 84 are retracted. As herein shown, the mechanism provided for this purpose may comprise an eccentric cam 63 fast on a cam shaft 65, and, a cooperating roller i1 carried by a lever 69 pivotally mounted at 1|. The lever i9 may be connected by a rod I3 to the arm 60 of the bell-crank, the arm being provided with a swivel I5 having an opening therein through which the rod may slide when moved to the left, thus leaving the bell-crank free to yield under the influence of the spring 86 when the

rollers

80, 84 are moved. A spring 11 coiled about the outer end of the rod and interposed between the swivel and a collar 'I9 fast on the rod, is arranged to yieldingly urge the bell-crank clockwise when the rod is moved to the right, A spring 8| may be provided to hold the roller 61 against its cam, and, a stop pin 83 may be provided for limiting the movement of the bell-crank in a` clockwise direction.

Referring now particularly to the adhesive applying mechanism indicated generally at 82 for applying the transverse stripes of

adhesive

28, 28 to the web, it will be observed that the applying roller 90 fast on the driven shaft |06 is arranged to run in a bath of adhesive |08 contained in a pan ||0, and, the adhesive may be maintained in a heated condition by the provision of electrical heating units indicated 'generally at ||2. I'he applying roller 90 may also be provided with the usual scraper unit indicated generally at ||4 which may include a blade IIB adjustably mounted with respect to the periphery of the roller 90 in a manner such as to control the film of adhesive carried by the roller.

As herein shown, the presser roller is rotatably mounted on a shaft |20 carried between arms |22 fast on arocker shaft |24 and is urged in a direction to effect engagement of the web |2 with the applying roller 90 by springs |26 connected to the arms |22. In order to control the movement of the presser roller 80 to effect application of the

transverse stripes

26, 28, the

applying roller shaft |08 is provided with two cams |28 one disposed on either side of the roller 90, and each cam is arranged to cooperate with a roller |30 carried on either end of the presser roller shaft |20. The major portion of each cam |28 is shaped to hold the presser roller 80 and the web out of engagement with the applying -roller, and is provided with two spaced low points |32, |34 arranged to permit the web to be pressed by the roller 80 into engagement with the applying roller to effect application of the

transverse stripes

26, 28 respectively.

In practice, the adhesive applying roller 90 is accurately ground or finished to enable a uniform film of adhesive to be carried thereby and, in order to limit the movement of the presser roller 80 and the web to effect transfer of a substantially uniform nlm of adhesive, a second cam member |36 comprising an accurately ground cylindrical disc is arranged to cooperate with the cam |28 to limit the movement of the roller |30 into the low points |32, |34 of the cam |28. In other words the disc |35 denes the actual low points of the cams |28, the points |32, |34 being cut to extend below the periphery of the disc |38. In practice, the discs |38 may be fast on the shaft |06 and the cams |28 adjustably secured thereto whereby to permit rotary adjustment of the cams |28 to dispose the transverse stripes in proper relation to the longitudinal stripes 22.

'Ihe adhesive applying mechanism indicated generally at 86 for applying the longitudinal marginal stripes 22 of adhesive to the web, as herein illustrated includes a relatively narrow adhesive applying roller 92 fast on the shaft |04 and arranged to run in a bath 'of adhesive contained in a pan |40, the adhesive being preferably maintained in a heated condition by the provision of electrical heating elements |42 disposed in the pan. The roller 92 may also be provided with an adjustable scraper unit |44 for distributing the adhesive evenly over the periphery of the roller. The presser roller 84 may and preferably will be mounted in a manner similar to the presser roller 80, being herein shown as rotatably carried between arms |46 fasten a rocker shaft |48 and arranged to be urged by a spring |50 in a direction to eifect engagement of the web with the applying roller 92. Provision is also made for controlling the movement of the' presser roller 84 to effect transfer of a uniform film of adhesive to the web to provide the longitudinal marginal stripes 22, and, as herein shown, the applying roller shaft |04 is provided at either end with similar cams |52 arranged to cooperate with rollers |54 provided on the presser roll shaft |55. Each cam |52 is provided with a high point |56 arranged to move`the presser roller and web away from engagement with the applying roller at predetermined intervals to discontinue the stripe adjacent the line of severance 24 of successive blank sections I8 of the web. During the remainder of each cycle of operation of the machine the rollers |54 are in engagement with cooperating accurately ground cylindrical discs |58 which in effect form the low points of the cams |52 to accurately control the film of adhesive transferred by the applying roller 92.

From the description thus far it will be observed that the adhesive applying mechanism thus far described, and illustrated in Fig. 3, operates to provide the web with successive patterns of adhesive comprising the longitudinal stripes 22, and the

transverse stripes

26, 28. In practice in many instances the

stripes

26, 28 may comprise one adhesive and the stripes 22 a different adhesive. The mechanism of Fig. 3 lends itself to the application of such different types of adhesive by reason of the two separate pans ||0, and` |40 as will be apparent from inspection of Fig. 3. For some purposes however it may be desirable that different types of adhesive be utilized for the top closure stripe 28 and the bottom closure stripe 26 of successive blank sections, and accordingly the mechanism may embody a third adhesive applying mechanism as indicated in- Fig. 4 wherein for example: the mechanism |60 may be arranged to apply a bottom closure stripe 26 of heat sealing adhesive; the mechanism |62, a top seam stripe 28 of high melt adhesive; and the mechanism |64, a longitudinal marginal stripe 22 of the same or a different type of adhesive.

In the embodiments of the invention above described it will be observed that in the application of adhesive to form the transverse stripes, the width of each stripe will depend upon the length of time the web is held against the applying roller and upon the rate of speed at which the web is moving, that is, the faster the movement of the web, the wider the stripe. In practice, when a relatively long lining bag is to be formed, the rate of speed of the paper must necessarily be increased to obtain the desired feed with relation to associated mechanisms of the packaging machine, and, in such cases, the width of the transverse stripe is liable to be unduly or unnecessarily wide. In order to avoid this condition, provision may be made for bodily moving the presser roll in the direction of travel of the web during the pressing or applying operation, and, as Villustrated in Fig. 5, this may be accomplished by mounting the presser roller |10 on an arm |12 pivotally carried by one arm |14 of a bell-crank rockingly mounted at |16. The second arm |18 of the bell-crank is provided with a roller arranged to cooperate with a cam |82 fast on a cam shaft |84 forming a part of the driving mechanism ofthe packaging machine. A spring |88 may be provided to urge the presser roller and the Web toward the applying roller |90, and, a spring |92 may be employed to hold the roller |80 against its cam. The applying roller shaft |94 may be provided with suitable cams |96 for cooperation with the roller |98 carried by the presser unit, as above described. With this construction it will be seen that in the operation of the device, when the c ams |96 permit the presser roller to urge the web into adhesive transferring engagement with the applying roller |90, the cam |82 effects a rocking movement of the bell-crank to lift the presser roller |10 and the latter follows along with the web during the transferring operation whereby to provide a relatively narrow transverse stripe of adhesive. The mechanism illustrated in Fig. 5 may also be used with advantage for the application of hot adhesive to oily paper such as the wax coated papers in which the oily surface of the web normally resists the application of adhesive. By the use of the above described mechanism a specic area of the web may be maintained against the applying roller for a slightly longer time, thus overcoming the inherent resistance of the wax paper to the application of the adhesive.

From the above description it will be observed that the present adhesive applying mechanism is particularly adapted for the application of a viscous adhesive to a continuously moving web, and, is capable of applying substantially uniform films of adhesive at predetermined spaced areas of the web defining seam and closure forming portions of a lining blank to be subsequently severed from the web for the production of lining bags.

While the preferred form of the invention has been herein illustratedv and described it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is:

1. An adhesive applying mechanism for applying adhesive to a longitudinally moving web comprising a rotatable adhesive applying roller, vmeans for rotating the roller to cause the portion of its surface in contact with the web to travel in a direction opposite to the direction of travel of the web, and means engaging the web for intermittently pressing the web into engagement with said applying roller to effect application of adhesive to spaced portions of the web, and additional means for moving said pressing means a substantial distance in the direction of travel ation.

2. .Adhesive applying mechanism, comprising means for continuously unwinding and advancing a web of bag forming material from a supply roll thereof, adhesive applying mechanism for applying adhesive to said continuously moving web including a rotatable adhesive applying roller, means for rotating the roller to cause the portion of its peripheral surface which contacts with the web to travel in a direction opposite to the direction of travel of said continuously moving web, a presser roller, means for advancing said presser roller from a retracted position to press the moving web into engagement with said adhesive applying roller at predetermined intervals to effect transfer of adhesive to selected spaced portions of the web and for returning said presser roller from advanced to retracted position, means including a spring urged guide roller engaged with the web and having a normal position in which it maintains the web relatively-taut during its travel past said adhesive applying mechanism, means mounting said spring urged roller for yielding in one direction from its normal position in the event of an abnormal tension condition in the web, and means operative under an abnormal tension condition in the web for positively moving said spring urged roller in the opposite direction to return the same to substantially its normal position, whereby to maintain a substantially uniform tension in the web being unwound from the supply roll.

3. An adhesive applying mechanism'as deiined in claim 2, including means for advancing the presser roller into contact with the web by movement thereof in the direction of travel of the web during the adhesive applying operation, and a cam coaxial with the adhesive applying roller rotatable therewith and having a periphery en- 8 gaged with the presser roller designed to limit the movement of the presser roller toward the adhesive applying roller, whereby to apply a uniform film of adhesive onto said web.

4. An adhesive applying mechanism' for applying adhesive to a longitudinally moving web, comprising a plurality of spaced apart, rotatable adhesive applying rollers, one of said rollers having a surface for applying a strip of adhesive longitudinally of the web and the other a surface for applying a strip of-4 adhesive' transversely of the web, means for rotating the adhesive applying rollers to cause the portion of the surface thereof in contact with the web to travel in a direction opposite to the direction of travel of the web, presser rollers engaging the web for intermittently pressing the web into engagement with said adhesive applying rollers to effect application of adhesive to spaced portions of the web, and additional means for moving the presser roller which engages the web with the transverse strip applying adhesive roller a substantial distance in the direction of travel of the web during the adhesive applying operation.

STANLEY R. HOWARD.

REFERENCES CITED The following references are of record in the file of this patenit:

UNITED STATES PATENTS i Date