US3838805A

US3838805A - Shrink-film capping machine

Info

Publication number: US3838805A
Application number: US00306982A
Authority: US
Inventors: R Amberg
Original assignee: Owens Illinois Inc
Current assignee: Graham Packaging Plastic Products Inc
Priority date: 1970-11-25
Filing date: 1972-11-16
Publication date: 1974-10-01
Anticipated expiration: 1991-10-01

Abstract

Counter top machine for shrink-film capping of containers in which a capping unit is mounted on a cabinet so that the lower end of the unit is spaced above the counter. The capping unit includes a sealing tube for receiving the upper end of the container as the container is manually moved upwardly and for directing hot air around the edges of the shrink-film closure, the central portion of which is held between a vertically movable plunger plate and the container and the hot air being supplied from a chamber containing electric heating elements and fed by an air valve controlled centrifugal blower, the air valve being actuated by upward movement of the container. A puncturing needle on the plunger punctures the closure and a heated knive on the unit severs the film. The cabinet contains a roll of shrinkable film which is fed in measured amounts by an electric motor drive between corrugated jaws which direct the film beneath the plunger plate, the drive being activated by a manually operable trigger lever located below the jaws. One of the jaws is toggle actuated for initial threading of the film between the jaws.

Description

United States Patent 11 1 Amberg [4 Oct. 1, 1974 1 SHRINK-FILM CAPPING MACHINE [57] ABSTRACT [75] Inventor: Ralph Gilb rt Amb r M ti ll Counter top machine for shrink-film capping of con- 1 d tainers in which a capping unit is mounted on a cabinet so that the lower end of the unit is spaced above [73] Asslgnee' owens'mmols Toldo Ohlo the counter. The capping unit includes a sealing tube [22] Filed; Nov, 16, 1972 for receiving the upper end of the container as the container is manually moved upwardly and for direct- [21] Appl' 306982 ing hot air around the edges of the shrink-film closure,

Related US. Application Dat the central portion of which is held between a verti- [62] Division of Sen Na 92 605 25 1970 cally movable plunger plate and the container and the hot air being supplied from a chamber containing 52 US. (:1 226/88 226/154 226/196 electric heating elements and fed by Valve [51] Int. Cl B6 5h 17/20 trolled Centrifugal blower the air Valve being actuated 58 Field Of Search 226/88 127 128 129 by upward movement of the container- A puncturing 226/134 152 8 needle on the plunger punctures the closure and a 7 heated knive on the unit severs the film. The cabinet [56] References Cited contains a roll of shrinkable film which is fed in measured amounts by an electric motor drive between UNITED STATES PATENTS corrugated jaws which direct the film beneath the 1,550,084 8/1925 Lorenz 156/462 plunger plate the drive being activated by a manually 3,558,109 H1971 Sofue 226/88 X Primary ExaminerRichard A. Schacher Attorney, Agent, or Firm-Brooks Haidt & Haffner operable trigger lever located below the jaws. One of the jaws is toggle actuated for initial threading of the film between the jaws.

7 Claims, 6 Drawing Figures ATENTEUUBT 11974 $838,805

sum 10: 4

IENTED BET Y 1974 saw 3 or 4 SHRINK-FILM CAPPING MACHINE This is a division of application Ser. No. 92,605, filed Nov. 25, 1970.

This invention relates to capping techniques and more particularly to the capping of receptacles, such as paper or plastic receptacles containing comestibles or liquids, with a closure of the shrink-film type.

Containers having shrink-film closures, and methods and apparatus for simultaneously forming and applying shrink-film closures to receptacles are known, being shown and described, for example, in U.S. Pat. Nos. 3,354,604, 3,354,605 and 3,354,614. An oversized piece of thin and shrinkable sheet material, such as polyethylene, is placed upon and across the receptacle mouth opening whereupon heat is applied to the peripherally extending excess polyethylene sheet material to shrink the same into somewhat bunched or wrinkled contact relation with the periphery of the receptacle while maintaining the central area of the polyethylene in relative cool condition so that it will not shrink. The resulting closure is relative elastic in its shrunken edge regions so that it may be easily removed from the receptacles using the fingers to slightly expand the shrunken periphery and slip the closure off the receptacle. it should be noted that such shrink-film closures are not actually bonded to the receptacle.

The present invention contemplates that shrink-film closures might be economically and easily formed on paper or plastic receptacles which have been filled with food, liquids, or the like by the merchant within a store where such items are sold over-the-counter.

It is apparent that, if shrink-film type closures are to be used for such purposes, the closure material must be shrunk into tightly fitting relation with the receptacle periphery so that it cannot be dislodged by inadvertent rough handling.

Moreover, it is apparent that such tight fitting shrinkfilm closure must be very quickly and very easily applied by the merchant if he is to take full advantage of the known economy inherent in the use of such closures. In addition, the machine which he uses to apply the closure must have a capability of accommodating receptacles of various heights and sizes, be relatively inexpensive and be readily loaded with the closure film. Also, the film should be fed automatically and in the correct size to the position where it is applied without requiring that the operator use special care or procedures.

In addition to the foregoing, it is recognized that relatively unskilled persons will be operating the shrinkfilm capping machine in soft drink stores, delicatessens and other stores, and it is therefore necessarythat the machine be rugged, very easily used, maintained and cleaned, and not require sensitive control during operation. Further, the machine should be capable of forming and applying the closures virtually instantaneously, and the time during which heat is applied should not be critical so that an overexposure of the capping film to heat will not mutilate or destroy the same. The present invention provides a shrink-film capping machine which includes all of such desirable features and advantages.

Although the use of an electric heating element adjacent to the portion of the film to be shrunk has certain advantages, such as noise reduction described in said US. Pat. No. 3,354,605, nevertheless, I have found that with the apparatus of my invention it is desirable to blow hot air around such portion using an electric heating element'and a blower in order to provide satis factory seals with receptacles having top openings of different sizes, to aid in preventing injury to an opera tor and to permit hand insertion of the receptacle into the capping head without requiring precise positioning of the receptacle. By the use of a centrifugal blower with a valve on its intake opening which is automatically opened when the receptacle is inserted in the capping head, the noise is kept to a minimum particularly during the time the valve is closed and capping is not being performed.

In the preferred embodiment of the invention, a single capping head unit is mounted on the front of a cabinet which may be placed on a counter. The capping head unit is mounted with its lower end above the base of the cabinet a distance sufficient to permit hand insertion of receptacles of various desired heights which it is desired to cap between such lower end and the counter top and to thereafter raise the receptacle and thereby insert at least the top portion thereof into the capping unit where the closure is heat shrunk.

The capping unit is similar to one of the capping units disclosed in said U.S. Pat. No. 3,354,604 but includes certain modifications. The unit of the invention is stationary and comprises a centrifugal blower at its top with an intake opening having a valve which is operated automatically when a receptacle is inserted in the unit. Air is directed downwardly by the blower into a chamber comprising a pair of spaced electric heating elements and around which the air flows. The chamber surrounds a canlike cylinder or sealing tube having peripherally disposed air outlets adjacent its lower end and encirclinga vertically movable plunger carrying a plunger plate with a disk engagable with the closure film. A film puncturing needle is carried by the plunger centrally of the plate to cause puncturing of the closure centrally thereof. A serrated edge, knife blade is mounted adjacent the lower end of the outside wall of the heating chamber and intermediate the plunger plate and the front of the cabinet so as to sever the closure film as the receptacle is inserted into the sealing tube. The knife blade is supported by a bar of good thermal conductivity metal, such as aluminum, which encases a cartridge type electric heater so that the blade is heated evenly and to a temperature which facilitates severing of the film.

The cabinet contains the closure film suitably mounted, and an electric motor for operating a film feed which comprises rollers engagable with the film and rotable by the motor through a one-tum clutch for feeding a measured amount of film beneath the plunger plate. The clutch drive, and hence, the film feed, is caused by the movement by an operator of a trigger lever at the front of the cabinet. The film is fed out of the cabinet between a pair of closely spaced, matching, corrugated jaws so as to produce rectilinear movement of the film as it leaves the jaws and so as to cause it to assume the proper position beneath the plunger plate in one second or less.

The lower jaw is pivotally mounted, and its position is controlled by a toggle mechanism which permits the jaws to be opened easily for initial placement of the closure film therebetween and to be subsequently closed.

To prepare the machine for operation, a roll of closure film is mounted in the cabinet, the jaws are opened and the forward or leading edge of the film is threaded between the jaws until it is adjacent the cutting edge of the knife blade. The jaws and the cabinet are then closed, and the heating elements, blower and film feed motor are turned on. After the air to be blown around the capping film has reached the correct temperature, a wait of a few minutes, the machine is ready for use.

To close a receptacle, the operator merely actuates the clutch trigger lever at the front of the cabinet, preferably while inserting the receptacle open-end up beneath the plunger plate and in a position lower than the film feed jaws, which causes the film in a measured amount, greater in length than the mouth diameter of the receptacle, to be fed beneath the plunger plate. After the film is so positioned, the operator raises the receptacle and presses the upper end thereof into the sealing tube until it can no longer move upwardly. This causes the receptacle to engage the film and press it against the plunger plate and then move the plunger plate upwardly. At the same time, the knife blade severs the film widthwise and the blower valve is opened so that in the uppermost position of the receptacle, hot air flows around the film edges not covered by the plunger plate, causing such portions of the film to shrink and tightly engage the upper portion of the outer wall of the receptacle in a short period of time, e. g. one to three seconds. The punching needle carried by the plunger produces a centrally disposed puncture in the closure as the receptacle is raised.

After the film has shrunk as described and the receptacle is thereby closed, the operator lowers the receptacle until it is clear of the sealing tube at which time it is removed from the machine which is then ready for receiving and closing the next receptacle. As the receptacle is lowered, the blower valve closes, quieting the blower and stopping, or substantially stopping, the flow of air out of the sealing tube openings.

Various objects, advantages and features of the invention will be more readily apparent from the following detailed description of the presently preferred embodiment thereof, which description should be considered in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of the complete apparatus of the invention;

FIG. 2 is a fragmentary, side elevation view, partly in cross section, of the apparatus illustrated in FIG. 1;

FIG. 3 is a further fragmentary, side elevation view, partly in cross section, of the apparatus illustrated in FIG. 1 and shows the parts thereof in their positions when the capping material is being heated and shrunk around the mouth of the receptacle.

FIG. 4 is a fragmentary, end elevation view, partly in cross section, of the apparatus illustrated in FIG. 1, and

FIGS. 5 and 6 are perspective views of the film feed wheels and feed jaws.

The preferred embodiment of the apparatus of the invention illustrated in FIG. 1 comprises a cabinet 10 having feet 11 for supporting the cabinet on a counter top. The cabinet 10 also comprises a semi-cylindrical cover 12 pivoted at its rear edge 13 to permit the cover 12 to be opened for the insertion of a roll of heat shrinkable film, such as bi-axially oriented, polyethylene film having a thickness of the order of 0.00075 inches. Matching corrugated jaws 14 extend from the front of the cabinet 10 and the heat shrinkable film is fed therebetween as described hereinafter.

A rod 15 extends from the side wall of the cabinet 10 and, as described hereinafter, it is used to open and close guide means in the form of the jaws 14 for the purpose of permitting easy feed of heat shrinkable film therebetween. The feed of the film from the jaws 14 is initiated by operation of a trigger lever or trip arm 16 mounted on the front of the cabinet.

A centrifugal blower, a chamber containing electrical heating elements and a sealing tube, all forming a sealing unit, are contained within a heat shield and cover 17 mounted on the cabinet 10. Plunger means including a plunger plate 18 extends downwardly from the sealing tube, and in its normal position shown in FIG. 1, it is immediately above the heat shrinkable film as it issues from between the jaws 14. The distance between the lower side of the plate 18 and the counter top on which the apparatus rests is selected so as to permit easy insertion of receptacles of various sizes to be sealed between such plate 18 and the counter top.

As shown in FIG. 2 a roll 19 of heat shrinkable film is mounted within the cover 12 and rides on a pair of freely rotatable rolls 20 and 21, the film 22 being fed from the roll 20 to the jaws 14 from which the film 22 issues in corrugated form. To assist in initial feeding of the film 22 between the jaws 14, the lower jaws 23 and an idler wheel 41 are mounted on an arm 25 which is pivotally supported on a shaft 26. The arm 25 and hence, lower jaw 23 and the wheel 41 are held in the positions thereof shown in solid lines by means of a toggle mechanism comprising a plate 27 having a bracket 28 extending therefrom and pivotally connected to an upper leg 29. The upper leg 29 is pivotally connected at one end to one end of a lower leg 30, as a 31, and the lower leg 30 is pivotally connected at its other end to a foot 32 supported from the base of the cabinet 10.

The toggle mechanism also comprises a compression spring 33 surrounding the upper leg 29, which spring bears againsta lock 34 in the form of a sleeve closely surrounding the lower end of the upper leg 29 and the upper end of the lower leg 30, but slidable thereon, and the lock 34 is limited in its downward movement by a stop pin 35 on the loer leg 30. The rod 15, also shown in FIG. 1, is secured to the lock 34, such as by welding, and when the rod 15 is manually moved upwardly the lock 34 moves upwardly and spring 33 is compressed. When the lock 34 has been moved upwardly a distance sufficient to substantially clear the end of the lower leg 30, and the rod 15 is moved to the right, the portions of the toggle mechanism assume the positions shown in dot-dash lines in FIG. 2, thereby permitting the lower jaw 23 to assume the position shown in dot-dash lines in FIG. 2. When the toggle mechanism and the lower jaw 23 are in such positions, it is a simple matter to feed the film 22 between the lower jaw 23 and the upper jaw 36 and to position the leading edge thereof adjacent the loer edge of a knife blade 37 which has a length at least as great as the width of the film 22.

Thereafter, the rod 15 is again raised and moved to the left, as viewed in FIG. 2, so that the

jaws

23 and 36 are closed, and when the rod 15 is released, the toggle mechanism and the jaws assume the positions shown in solid lines in FIG. 2, the lock 34 retaining the toggle mechanism and the jaws in such positions.

Referring to FIGS. 26, the film 22 is automatically advanced a predetermined amount by means of an electric drive motor 38 connected to a pair of

rubbertired drive wheels

39 and 40. Thus, the rubber-

tired wheels

39 and 40 engage the upper surface of the film 22, and the lower rubber-tired,

idler wheels

41 and 42 engage the lower surface of the film 22. When the

wheels

39 and 40 are rotated in a clockwise direction, as viewed in FIG. 2, the film 22 is fed from right to left as viewed in FIG. 2. The amount of film 22 which is so fed is greater than the diameter of the mouth of the receptacle 43 to be covered, and the width of the film 22 is also greater than the diameter of the mouth of the receptacle 43.

The film 22 is relatively thin and flexible and will bend easily. Accordingly, if one attempted to feed the film into the position between the plunger plate 18 and the receptacle 43 shown in FIG. 2 while keeping the film in flat form, it would be found that the film would not follow a rectilinear path as viewed from the side. Instead, the film would droop or curve downwardly from the jaws 14 as it issues therefrom and therefore, would not assume the desired position. It has been found that if the jaws between which the film 22 is fed are corrugated and preferably are so dimensioned with respect to the width of the film that the edges of the film extend upwardly as they issue from the jaws 14, the film 22 can be caused to follow a rectilinear path and positioned as shown in FIG. 2.

The construction of the jaws 14 is shown in greater detail in FIGS. 5 and 6. As shown therein, the upper jaw 36 has a corrugated form and is supported by a plate 43, and both the upper jaw 36 and the plate 43 have apertures therein permitting the

drive wheels

39 and 40 to engage the film 22 as it passes between the jaws. The lower jaw 23 has a mating or matching corrugated form and is supported by a plate 44, both the lower jaw 23 and the supporting plate 44 having apertures therein permitting the

idler wheels

41 and 42 to engage the lower surface of the film 22 thereby causing the film 22 to be engaged between the nips of the

wheels

39 and 41 and of the

wheels

40 and 42. It will be noted that the jaws have flat portions 45-48 intermediate the adjacent angular portions and where the wheels 3942 engage the film 22.

Preferably, the

jaws

23 and 36 are made of metal, and they are spaced apart a distance approximately equal to, or slightly greater than, the thickness of the film 22. As the

wheels

39 and 40 rotate, the

wheels

41 and 42 also rotate causing the film 22 to move into the position shown in FIG. 6. During such movement, the film 22 assumes the'corrugated shape shown in FIG. 6, and the film 22 follows a rectilinear path as it issues from between the

jaws

23 and 36. It should also be noted that the shaping of the

jaws

23 and 36 is such with respect to the width of the film 22 that the side edge portions of the film 22 are directed upwardly as they leave the jaws.

Referring now to FIGS. 2-4 the electric motor 38, which comprises a conventional speed reduction gear train, is interconnected through a well known type of clutch mechanism 49, a pair of

sprockets

50 and 51 and a roller chain 52 with the shaft 53 which drives the

wheels

39 and 40. When the apparatus of the invention is energized, the motor 38 operates continuously but the shaft 53 rotates only when the restraining means or cam 54 forming part of the clutch mechanism 49 is released. The cam 54 is normally restrained by a release arm 55 engaging a projection 54a on the cam 54, but when the release arm 55 is disengaged from the projection 54a by moving it to the left, the cam 54, the

sprockets

50 and 51 and hence, the shaft 53 as well as the

wheels

39 and 40 will rotate, the cam 54 rotating for only one turn and hence, each time that the release arm 55 is disengaged from the projection 54a. Accordingly, the film 22 will be advanced by a fixed, predetermined amount each time that the cam 54 is permitted to rotate.

The release arm 55 is pivotally mounted at 56 and carries a sear 57 pivotally mounted thereon. The sear 57 is urged downwardly and the release arm 55 is urged into engagement with the projection 54a by a spring 58. A finger 59 pivotally mounted at 60 engages a projection on the sear 57 and is urged to the right as viewed in FIG. 2 by a spring 61. The relative positions of the sear 57 and the finger 59 may be adjusted by means of a screw 62, a sloping face of the sear 57 engaging the end face of the screw 62 which acts as a stop.

At one end thereof, a trip rod 63 pivotally engages the finger 59, and at the other end thereof it is in pivotal engagement with arm 64. The am 64 is secured to and moves with an arm 65 which supports the trigger lever or trip arm 16, and both arms 64 and 65 are pivotally mounted at 66.

When the trip arm 16 is manually moved from the position shown in solid lines in FIG. 2 to the position shown in dot-dash lines in FIG. 2, the arm 64 pivots about the point 66 causing the finger 59 to move the sear 57 to the left as viewed in FIG. 2. The sear 57 moves the release arm 55 out of engagement with the projection 54a thereby permitting the

wheels

39 and 40 to drive the film 22 into the position shown in FIG. 2. As the sear 57 moves to the left it also moves upwardly at its left end because of the engagement of its sloping face with the screw or stop 62, and at a predetermined point in its movement, the projection on the sear 57 will separate from the finger 59 and the sear 57 will ride over the end of the finger 59 due: to the force of the spring 58 so that if the trip arm 16 is manually held in the position shown in dot-dash lines in FIG. 2 the release arm 55 will still be permitted to re-engage the cam projection 54a and stop it after one revolution.

When the trip arm 16 is released, it will assume the position shown in FIG. 2 and cause the finger S9 to engage the projection on the sear 57 and therefore, will be in a position to again release the cam 54 when the trip arm 16 is subsequently operated.

The knife 37 is made of steel and it has a serrated lower edge which is engageable with the film 22 when it is raised as described hereinafter and is mounted on a bar 67 of good thermal conductivity and may, for example, be made of aluminum. The bar 67 contains an electric heater 68, which may, for example, be a conventional catridge type heater, for heating the knife 37 to a temperature, e.g., 325340F, which will facilitate cutting of the film 22. The bar 68 is supported by a pair of brackets such as the bracket '69 which carries a clamp 70 surrounding an insulating bushing 71 which receives the bar 67.

Below the bar 68 is a stripper 72 which is made of heavy wire bent into a U shape and which is freely ro- I tatable about an axis 73. As described hereinafter the stripper 72 aids in stripping the leading edge of the film 22 from the knife 37 after the film 22 has been severed 'by the knife 37, the stripper 72 having a length in a direction perpendicular to the plane of the drawing at least equal to the width of the film 22 and a weight sufficient to strip the film 22 from the knife 37. The lowermost position of the stripper 72 may be adjusted by the screw 74 which is engageable with a side portion of the stripper 72, and normally the stripper 72 is positioned so as to rest near the top of the upper jaw 36.

The plunger plate 18, which may be made of metal, has a rubber disk 75 secured to the face thereof and is supported by a tubular shaft 76 which has a bore which is circular in cross section and which slidably receives a shaft 77 which is hexagonal in cross section. It has been found that under the conditions where the apparatus of the invention is used, dirt, food and liquids frequently enter into the space between the tubular shaft 76 and the shaft 77. It has also been found that such dirt, etc., will cause binding of the shaft 76 on the shaft 77 if they have a close fit, such as is the case when the cross sectional shape of the bore of the shaft 76 corresponds closely to the cross sectional shape of the shaft 77. For example, if the cross sectional shape of the bore is circular and the cross sectional shape of the bore 77 is also circular and the dimensions of both cross sections are approximately equal, then after a period of use binding may occur when it is attempted to slide the shaft 76 with respect to the shaft 77 as described hereinafter. Accordingly, the cross sectional shape of the bore of the shaft 76 is made different from the cross sectional shape of the shaft 77 so that portions of the exterior of the shaft 77 are spaced from portions of the interior of the shaft 76, and it has been found that satisfactory results are obtained when the cross sectional shape of the bore 76 is circular and the cross sectiona shape of the exterior of the shaft 77 is hexagonal as described.

The tubular shaft 76 is provided with a slot 78, and the shaft 77 has a pin 79 extending therefrom and into the slot 78 in the shaft 76. The pin 79 and the slot 78 permits the shaft 76 to slide axially of the shaft 77 without substantial rotation of the shaft 76, and hence, the plunger plate 18, and also restricts downward movement of the shaft 76 and hence, of the plunger plate 18.

The shaft 77 is supported from a mounting disk 80 which is secured to a mounting plate 81. The shaft 77 has an enlargement or washer 77a therearound engagable with the upper end of the shaft 76 when it is moved upwardly. The shaft 77 also has a needle 77a mounted at the lower end thereof and the plate 18 and disk 75 have central apertures therein permitting the needle 77a to pass therethrough when the plate 18 is moved upwardly, the needle 77a, puncturing the film closure for purposes well known in the art. Of course, if desired, the needle 77a may be omitted.

The mounting plate 81 is supported by a further mounting plate 82 secured to an outer shell 83. A pair of

disks

84 and 85 of heat insulating material are disposed on opposite sides of the mounting plate 82, and the mounting plate 81 is spaced from the lower disk 85.

by a pair of

bushings

86 and 87.

-A sealing tube 88, preferably made of metal, is secured to the mounting disk 80 and has an inner diameter slightly larger than the diameter of the plunger plate 18. The tube 88 has a plurality of holes 89 extending through a wall thereof and communicating with the heating chamber 90 surrounding the sealing tube 88. Such holes 89 permit the flow of hot air from the heating chamber 90 to the surface of the heat shrinkable film on a receptacle to cause shrinking of such film as described hereinafter.

For cleaning purposes, the tube 88 with the disk preferably are secured to the mounting plate 81 so that they may be easily removed as a unit, and they may be secured thereto as described in said US. Pat. No. 3,354,604. It will also be noted that in the preferred embodiment, the plate 18 substantially closes the end of the tube 88 when the plate 18 is in its lowermost position thereby restricting the outflow of heating air out of the sealing tube 88 and the heating chamber 90.

The wall of the sealing tube 88 forms one wall of the heating chamber 90 and the outer shell 83 forms an other wall thereof. The heating chamber contains a pair of

electric heating elements

91 and 92, each of which may be a conventional spirally wound coil of resistance wire. The

heating elements

91 and 92 are supported by a plurality of brackets 93 supported from the inner surface of the outer shell 83.

The mounting plate 82 and the disks 84 and are provided with centrally aligned apertures so as to provide an air passageway 94 which communicates at one end with the outlet of a centrifugal blower 95 and which communicates at the other end with the heating chamber 90. Accordingly, when the blower 95 is permitted to blow air through its outlet the air passes downwardly through the passageway 94 to the upper end of the heating chamber 90, flows radially outwardly in the space between the mounting plate 81 and the disk 85 and then passes downwardly past the

heating elements

91 and 92 where it is heated. After passing the

heating elements

91 and 92, the air flows radially inwardly through the holes 89 in the sealing tube 88. Accordingly, the air is heated not only by the

elements

91 and 92 but also by the heated walls of the outer shell 83 and of the tube 88.

The centrifugal blower 95, which in one embodiment of the invention had a rating of 15 c.f.m., operates continuously when the apparatus is energized, but substantially no air is supplied thereby to the heating chamber when a blower valve 96 located at the inlet of the blower is closed.

The valve 96 has a disk 97 secured to the face thereof and may, for example, be made of felt. The disk 97 effectively closes the inlet of the blower 95 when the valve 96 is closed. Valve 96 is pivotally mounted by a shaft 98' and is urged to the closed position by a spring 99 extending between a mounting bracket 100 and an arm 101 forming part of the valve 96. Accordingly, the valve 96 may be rotated from the closed position shown in FIG. 2 to the opened position shown in FIG. 3.

A lift arm 102 is securedto the valve 96 at 103, such as by a welding, and the end of the lift arm 102 is engagable by the upper end of a push rod 104. The lower end of the push rod 104 rests on the upper surface of the plunger plate 18 so that when the plunger plate 18 is raised, as described hereinafter, the push rod 104 lifts the arm 102 and opens the valve 96, the push rod 104 being slidable in a bushing 105 extending through the mounting plate 82 and the

disks

84 and 85.

After a roll 19 of heat shrinkable film has been placed in the apparatus and the film has been threaded between the

jaws

23 and 36 as described hereinbefore and after the drive motor 38, the

heating elements

91 and 92, and the blower 95 have been electrically energized in a conventional manner and a short period of time has elapsed to permit the heating chamber 90 to warm-up, the apparatus of the invention is ready for use. At this point, the drive motor 38 is operating, but the film 22 is not being fed because of the engagement of the release arm 55 with the projection 54a on the cam 54. Also, at this time the motor of the blower 95 is operating but little, if any, air is being delivered to the heating chamber 90 because the valve 96 is closed. Although a centrifugal blower is normally very quiet in operation, any noise normally produced thereby is further reduced by virtue of the fact that the valve 96 is closed which lowers the perceptible noise of the blower 95 and which substantially eliminates noise produced by air flow.

When the operator desires to cap a receptacle 43 the operator moves the trip arm 16 from the position shown in solid lines to the position shown in dot-dash lines in FIG. 2, either before placing a receptacle 43 in the position shown in FIG. 2, or while so placing a receptacle 43 in such position. Operation of the trip arm 16 causes release of the cam 54 in the manner heretofore described and causes the film 22 to be fed rapidly, e.g. less than a second, into a position beneath the plunger plate 18 and above the receptacle 43 as shown in H6. 2. The operator then raises the receptacle 43 causing the mouth thereof first to engage the under surface of the film 22 and then to press the upper surface of the film 22 against the disk 75 on the plunger plate 18. The major portion of the film 22 extendingfrom the jaws 14 is then held between the upper rim of the receptacle 43 and the disk 75.

As the operator continues to raise the receptacle 43, the plunger plate 18 moves upwardly, the stripper 72 is moved upwardly by the film 22 and the film 22 eventually reaches the cutting edge of the knife 37 which severs the film 22 widthwise. The weight of the stripper 72 causes the film 22 to separate from the knife 37 if 40 any portion thereof happens to stick to the knife 37, and the stripper 72 returns to its lowermost position shown in FIG. 2. As the operator continues to raise the receptacle 43 the plunger plate 18 continues to move upwardly until further upward movement thereof is prevented by the engagement of the upper end of the shaft 76 with the enlargement or washer 77b at the under surface of the mounting disk 80. At this point, the receptacle 43 is in the position shown in FIG. 3 where the portion of the film 22 extending outwardly from between the disk 75 and the rim of the receptacle 43 is folded downwardly and is exposed to heated air issuing from the holes 89. During the last portion of the upward movement of the receptacle 43, the film closure is centrally punctured by the needle 77a.

As the plunger plate 18 is moved upwardly, the valve 96 is opened because the push rod 104 is moved upwardly by the plunger plate 18 and operates the lift arm 102. Accordingly, as shown in Flg. 3 the valve 96 is fully opened when the receptacle 43, and hence, the plunger plate 18, have been raised to their uppermost positions. Because the valve 96 is open, the blower 95 delivers air to the heating chamber 90 where it is heated, and such heated air flows through the holes 89 and onto the film 22 folded downwardly around the receptacle 43 causing it to shrink around the upper portion of the receptacle 43 in a well known manner, the

required period of exposure of the film 22 to such hot air being relatively short.

The operator then lowers the receptacle 43 which has now been capped, and when. the top thereof has reached a position below the lower edge of the sealing tube 88, the receptacle 43 may be removed from beneath the plunger plate 18. Thereafter, the apparatus of the invention is ready to receive and cap another receptacle in the manner hereinbefore described.

It will be apparent from the foregoing that the apparatus of the invention is relatively simple to operate and may be used by relatively unskilled personnel. Furthermore, the apparatus caps the receptacles rapidly and with a minimum of effort on the part of the operator. Due to the fact that the blower 95 is not blowing air when the apparatus is not actually capping a receptacle, little, if any, hot air issues from the apparatus when it is not being used for such purposes and the blower noise is kept to a minimum.

It should also be noted that receptacles having many different heights and mouth diameters equal to or less than the diameter of the disk 75 may be capped by the apparatus. Since the shrinking of the film is caused by heated air, it is not necessary that the portion of the film to be shrunk be immediately adjacent the inner wall of the sealing tube 88.

Although a preferred embodiment of the invention has been illustrated and described, it will be apparent to those skilled in the art that various modifications thereof may be made without departing from the principles of the invention.

What is claimed is:

ll. Apparatus for feeding a relatively thin film along a rectilinear path extending transversely to the force of gravity and from said apparatus without support therefor along said path, said apparatus comprising a pair of matching corrugated jaws spaced apart throughout their width a distance substantially equal to the thickness of said film, one of said jaws being pivotally mounted and being movable from a first position in which the film engaging surface thereof is substantially parallel to the film engaging surface of the other of said jaws to a second position in which the film engaging surface thereof is angularly disposed with respect to, and in spaced a farther distance away from, the film engaging surface of said other jaw, toggle means for moving said one jaw from said first position to said second 7 position and vice versa, said toggle means comprising a first leg connected at one end to said one jaw, a foot spaced from said one jaw, a second leg pivotally connected at one end to the other end of said first leg and at its other end to said foot, and a sleeve slidably mounted on said legs and movable from a first position in which it encircles the interconnected ends thereof to a second position where it encircles only one of said legs, and means engageable with said film for moving said film between and through said jaws and outwardly therefrom.

2. Apparatus as set forth in claim 1 further comprising a stop mounted on said first leg at a position thereon spaced from said interconnected ends, a spring on said first leg and acting between said stop and said sleeve to urge said sleeve into said first position and a further stop on said second leg at a position thereon spaced from said interconnected ends and engagable with said sleeve for retaining said sleeve in said first position.

3. Apparatus for feeding a relatively thin film along a rectilinear path extending transversely to the force of gravity and from said apparatus without support therefor along said path, said apparatus comprising a pair of matching corrugated jaws spaced apart throughout their width a distance substantially equal to the thickness of said film, and means engageable with said film for moving said film between and through said jaws and outwardly therefrom, said means for moving said film comprising rotatable means engageable with said film, motor means, a clutch interconnecting said motor means and said rotatable means, said clutch comprising an actuating member, manually operable means, and separable means interconnecting said manually operable means and said actuating member, said separable means comprising means for disconnecting said manually operable means and said actuating means when said manually operable means is moved a predetermined distance.

4. Apparatus as set forth in claim 3 wherein said separable means comprises a first pivotally mounted member connected to said actuating means and movable both around and radially of the pivot axis thereof, said first member having a projection thereon, a second member engagable with said projection and movable radially of the pivot axis of said first member, means interconnecting said second member and said manually operable means, and means engagable with said first member for causing it to move around its pivot axis when it moves radially thereof, whereby movement thereof by said second member disengages said second member from said projection.

5. Film feed apparatus comprising rotatable means engagable with said film, motor means, a clutch interconnecting said motor means and said rotatable means, said clutch comprising an actuating member, manually operable means, and separable means interconnecting said manually operable means and said actuating member, said separable means cmprising means for disconnecting said manually operable means and said actuating means when said manually operable means is moved a predetermined distance.

6. Film feed apparatus as set forth in claim 5, wherein said separable means comprises a first pivotally mounted member connected to said actuating means and movable both around and radially of the pivot axis thereof, said first member having a projection thereon, a second member engagable with said projection and movable radially of the pivot axis of said first member, means interconnecting said second member and said manually operable means, and means engagable with said first member for causing it to move around its pivot axis when it moves radially thereof, whereby movement thereof by said second member disengages said second member from said projection.

7. Film feed apparatus as set forth in claim 5, wherein said separable means comprises a pivotally mounted release arm engagable with said clutch actuating member, a sear having a sloping face and a projection thereon, said sear being pivotally mounted, at a portion thereof spaced from said face and said projection, on said release arm and at a point on the latter spaced from the pivot axis thereof, a finger movable toward and away from said release arm, said finger having a portion thereof in engagement with said projection, means interconnecting said finger and said manually operable means for moving said finger by said manually operable means, and means engagable with said sloping face for separating said projection and said finger when said finger has been moved a predetermined distance away from said release arm.

Claims

1. Apparatus for feeding a relatively thin film along a rectilinear path extending transversely to the force of gravity and from said apparatus without support therefor along said path, said apparatus comprising a pair of matching corrugated jaws spaced apart throughout their width a distance substantially equal to the thickness of said film, one of said jaws being pivotally mounted and being movable from a first position in which the film engaging surface thereof is substantially parallel to the film engaging surface of the other of said jaws to a second position in which the film engaging surface thereof is angularly disposed with respect to, and in spaced a farther distance away from, the film engaging surface of said other jaw, toggle means for moving said one jaw from said first position to said second position and vice versa, said toggle means comprising a first leg connected at one end to said one jaw, a foot spaced from said one jaw, a second leg pivotally connected at one end to the other end of said first leg and at its other end to said foot, and a sleeve slidably mounted on said legs and movable from a first position in which it encircles the interconnected ends thereof to a second position where it encircles only one of said legs, and means engageable with said film for moving said film between and through said jaws and outwardly therefroM.