US2229121A

US2229121A - Method and apparatus for operating on sheet material

Info

Publication number: US2229121A
Application number: US204623A
Authority: US
Inventors: Norman H Nye; Ralph L Penn; Ralph W Penn
Original assignee: EDWIN J MCILVRIED
Current assignee: EDWIN J MCILVRIED
Priority date: 1938-04-27
Filing date: 1938-04-27
Publication date: 1941-01-21
Anticipated expiration: 1958-01-21

Description

Jan. 21, 1941. NYE 2,229,121

METHOD AND APPARATUS FOR. OPERATING ON SHEET MATERIAL Filed April 27, 1938 3 Sheets-Sheet l INVENTORJ YYOfiNH/Y H r5 19:94PM A. PEN/Y 16442 M Pew/v f m z a z JanlZl, N H NYE ETAL METHOD AND APPARATUS FOR OPERATING 6N SHEET MATERIAL 3 .Sheats Sheet 2 Filed April 27, 1938 3 M W M M N 3 0 0mm 9 5 W2: Z M m oMoMo a M M m: 00 o oo r.|,|m1 W1 7 1 7 0 I 5 3 M m y a INVENTORS IYOkMfl/l fir: 41 PH Z. 011 1904! h. PEN/Y W 7 55 ATTORN 6 Jam 21, 1941. N. H. NYE EIAL METHOD AND APPARATUS FOROBERATING ON SHEET MATERIAL Filed April 27, 1938 3 Sheets-Sheet 3 W I 2a 70' 70 75 1 ll 7 1! INVENTORS Nae/1011b! NYE 694 Ph 4. Paw/v Patented Jan. 21, 1941 PATENT OFFICE METHOD AND APPARATUS FOR OPERATING ON SHEET MATERIAL Norman H. Nye and Ralph L. Penn, Cuyahoga Falls, and Ralph W. Penn, Akron, Ohio, assignors of one-fourth to Edwin J. Mcllvried, Stow,

Ohio

Application April 27, 1938, Serial No. 204,623

14 Claims.

This invention relates to a method and apparatus for operating on sheet material for the production of bags or envelopes and other articles of this character. Our method and apparatus are 5 especially suitable for carrying out operations on thin thermoplastic or heat-sensitive sheet inaterial, that is, sheet material which is subject to softening and severance by the application of heat and pressure thereto, such as cellulo sheeting or the rubber sheeting known so mercialiy as Pliofllm." The mention of specific forms of such sheet material is only by way of example however, and it should be understood that our method and apparatus are capable of successful operation on various other kinds of sheet material.

An object of our invention is to provide an im- 7 Another object (or. as-49) --i travel of the rotary member to dislodge the bags f of our invention is to provide improved apparatus with which our method of operating on sheet material can be rapidly and economically carried out. I

Still another object of our invention is to provide improved means for applying heat and pressure to sheet material being advanced.

Yet another object of our invention is to provide improved apparatus, of this character, embodying a rotary member having spaced elements thereon to be engaged by sheet material overlying such member and in which means is provided for creating a fluid pressure differential on opposite sides of thematerial for pressing the same against proved method for the rapid and economical prpy" said elements.

duction of bags or the like, in which heat.. and pressure are applied along one edge of a strifi'of superimposed layers of sheet material to unite such layers therealong, and in which heat and pressure are then applied to the strip along longitudinally spaced transverse lines for severing the strip into sections and at the same time sealing the adjacent severed edges to form bags.

Another object of our invention is to provide an improved method for operating on sheet material, in which the material passes over a rotatable member having heating elements and in which a fluid pressure differential between opposite sides of the material acts to press the same against the heating elements.

Still another object of our invention is to provide an improved method of the character just mentioned, in which the fluid pressure differential produces a resultant force tending to press the sheet material against the heating elements during a portion of the travel of the rotary member and, during another portion of the travel of the rotary member, produces a resultant force tending to dislodge the material therefrom.

A further object of our invention is to provide an improvement in the production of bags, or the like, in which a strip comprising superimposed layers of sheet material is subjected to heat and pressure along an edge thereof to unite the layers hereaiong and is then passed over-a rotary member having spaced heating and severing elements adapted to sever the strip into sections and to seal the adjacent severed edgesto form bags, and in which a fluid pressure differential acts during a portion of the travel of the rotary member to press the material against the heating and severing elements and acts during another portion of the It is also an. object of our invention to provide improved apparatus, of the type referred to, in which means is provided for electrically heating the elements of the rotary member.

, Other objects and advantages of our invention will be apparent from the following description when taken in conjunction with the accompanying sheets of drawings in which,

Fig. 1 is aside elevation of a machine constructed according to our invention and which may be used in carrying out our method;

F g. 2 is a front elevation of the machine;

Fig. 3 is a plan view, somewhat diagrammatic in form, illustrating the progressive treatment of the sheet material being acted upon;

Fig. 4 is a partial vertical sectional view taken through the machine as indicated by line 4-4 of Fig. 1, and illustrating the construction of the rotary drum;

Fig. 5 is a detached end view of the drum;

Fig. 6 is a side elevation showing a portion of the apparatus of Fig. 1 on a larger scale;

Fig. '7 is a front elevation showing a portion of the machine on a larger scale than in Fig. 2;

Fig. 8 is a partial vertical sectional view taken as indicated by line 8-8 of Fig. 2;

Fig. 9 is a partial vertical sectional view taken as indicated by line9-9 of Fig. 7;

Fig. 10 is a partial longitudinal sectional view taken through the drum as indicated by line l0--l0 of Fig. 1 and illustrating constructional details thereof;

Fig. 11 is a partial transverse sectional view taken through the drum as indicated by line I i-i I of Fig. 10; v

Fig. 12 is a partial transverse sectional view taken through another drum and illustrating a. modified construction.

Fig. 13 is a partial transverse sectional view similar to-that of Fig. 11, but illustrating another modified construction.

Fig. 14 is a partial front elevation similar to that of Fig. 7 but showing a modified arrangement; and v Fig. 15 is a partial vertical sectional view taken on line |5-|5 of the modified arrangement of Fig. 14.

More detailed reference will now be made to the accompanying drawings in which we have illustrated our improved method and apparatus for operating on sheet material, but before proceeding with the detailed description it should be understood that although the machine illustrated in the drawings represents what we now regard to be the preferred form of our apparatus, the invention may be embodied in various other machines and our method may be carried out in various other ways and on various other kinds of apparatus than herein specifically described.

Our method and apparatus for operating on sheet material is well suited to the production of bags from the thin thermoplastic sheet material commercially known as Pliofllm, and, therefore, are hereinafter described in connection with this material and the production of bags therefrom. It should be understood, however, that the specific reference to this material and to the particular articles mentioned, is made without intent to limit the invention because our method and apparatus are capable of operation on other materials and are adaptable to the production of various other articles.

In general, our method contemplates the advancing or feeding of the sheet material, preferably in the form of a strip |5 comprising overlying or superimposed layers l6 and I1. Heat and pressure are applied to the strip along a longitudinal line thereof as it is being advanced to thereby render the material soft and tacky and unite the layers l6 and I1 along such line. The line along which the heat and pressure are applied is preferably, though not necessarily, adjacent an edge of the strip such as the line I8 indicated in Fig. 3. The strip then passes over a. rotatable member or drum in overlying relation to heating and severing elements and is pressed against such elements to cause heating and softening of the material along lines or areas l5 extending transversely of the strip as shown in Fig. 3 and which areas are spaced longitudinally of the strip a distance corresponding with the circumferential spacing of the elements. The pressure of the material against the elements, combined with the softening or fusing of the material caused by the heating thereof, results in a severing of the strip transversely along each of the areas or lines l9 to thereby cut the strip into a plurality of similar sections 20. During the severing of the strip into the sections 20, the pressure applied to the heatsoftened material causes the adjacent severed edges of the sections to be fused together to thereby seal the layers of the sheet material along the longitudinal edges of the sections to form the bags or envelopes 2 I. As will be readily seen from Fig. 3 the bags or envelopes thus formed have the overlying sheets or walls thereof sealed together along the two side edges and one end thereof, but are unconnected at the other end to permit material to be inserted into the bag or envelope.

In Figs. 1 and 2 we show a machine for carrying out our method and which operates very satisfactorily. As shown in the drawings, this machine may comprise an upright frame 23 and a ro atab e member or drum 25 operably mounted thereon and to which the strip material I5 is supplied. The frame 23 may be of hollow construction to provide a chamber 24 adapted to contain fluid pressure and into which at least a portion of the drum extends. This frame may comprise a pair of upright plates 26 spaced laterally to provide the space or chamber 24 therebetween and having aligned openings 28 in which end portions of the drum 25 operate. Sheet material 29 conforming to the outline of the frame members 26 is connected to the edges thereof to provide a connection between these members and to enclose the space therebetween to complete the chamber 24.

As shown in Figs. 1 and 4, the openings 28 preferably extend across the front edges of the frame members 26 so that a segment of the drum 25 will project from the chamber 24. At this point the sheet material 29 is omitted to define a laterally extending opening 30 which leads into the chambar and through which successive portions of the drum surface are exposed to atmosphere as the drum is rotated. The drum may be mounted on the frame in any suitable manner, such as by providing a pair of brackets 3| on the frame members 26 and in which the shaft 32 of the drum is supported by the bearings 33. The drum is constructed of a length to accommodate a strip l5 of the desired maximum width and such that its ends project through and substantially close the openings 28 of the frame members 26. Driving means of any suitable form may be provided for the drum such as the pulley 32 on the shaft 32 v and a belt 32 connecting the same with an electric motor or other power device.

At a point adjacent the drum 25 the frame 23 is provided with suitable means for supporting a stock of the Pliofllm" or other sheet material which is to be supplied to the drum. This stock supporting means may comprise a lateral frame projection 23 and a bracket-like member 34 mounted thereon and having a pair of laterally extending substantially parallel spindles 35 and 36 upon which rolls 31 and 38 of the sheet material are supported respectively for unwinding of the layers l6 and H.

The strip l5 may be drawn from the rolls 31 and 38 by a pair of cooperating feed rolls 40 and 4| between which the strip passes. The roll 40 may be suitably mounted in a pair of brackets 42 which are carried by the frame members 26 and rotates about an axis substantially parallel with the axis of rotation of the drum 25. This roll transfers or lays the strip i5 onto the drum and is preferably located adjacent the lower edge of the opening 30 so that the maximum amount of wrap for the strip can be had. The roll 40 may be driven by any suitable means for advancing the strip |5 at the desired rate and is preferably driven at a speed proportional to the speed of rotation of the drum 25. As shown in Fig. 2. this roll may be driven from the drum shaft 32 as by means of gears 44 and 45 which are connected, respectively with the drum shaft and roll.

The feed roll 4| cooperates with the driven roll 40 for pressing the strip l5 thereagainst. The roll 4| is mounted on the brackets 42 in a manner to provide for adjustable movement toward and from the roll 40 and may be retained at the adjustment which provides the desired pressure on the strip.

The heat and pressure applied to the strip l5 for connecting the layers l6 and H along the longitudinal line l8 may be applied at a point between the rolls of stock and the feed rolls 40 and 4|. For'this purpose we provide a pair of cooperating disk-like rolls 56 and between which the strip l5 passes. The rolls 56 and 5| are mounted respectively in

brackets

52 and 53 which are adjustable laterally of the machine, that is, transversely of the strip, preferably by being slidably mounted on a pair of

bars

54 and 55 carried by the brackets 42. The lateral adjustment thus provided for the

brackets

52 and 53 permits shifting of the rolls 56 and 5| to the desired point of operation on the strip |5.- In this instance the rolls 56 and 5| are arranged to act on the strip l5 adjacent one end thereof as shown in Figs. 2 and '1.

The bracket 52 may be held against swinging on its bar 54 by the clamping action of a set screw 56 so that the roll 56 may act as an anvil or backing roll against which the strip I5 is pressed by the roll 5|. The bracket 53 is preferably arranged to swing on the bar 55 so that the roll 5| may be swung toward or away from the backing roll 56. The bracket 53 may be normally biased to press the roll- 5| against the roll 56 as by means of atension spring 51 having one end thereof connected to a stud or extension 56 and its other end anchored on the transversely extending tie rod 59.

Ahead of the rolls 56 and 5|, and at a point adjacent thereto, we may provide strip-guiding means such as a pair of laterally extending stationary bars 59- mounted in the brackets 42 and between which the strip passes. These bars serve to guide the strip and also assist in maintaining the strip in a smooth and flat condition.

The rolls 56 and 5| apply both heat and pressure to the strip l5 for the purpose explained above, and as a source of heat for these rolls we provide an electric heating device 66 which may be mounted on the

bars

54 and 55 in adjacently spaced relation to the rolls. This'heating device 66 may comprise a body 6|, formed of insulating material, and having electric heating units 62 and 63 mounted thereon. These heating units may correspond generally as to size and shape with the rolls 56 and 5| and are mounted on the insulating body 6| so as to be disposed substantially opposite, and in adjacent relation to, the respective rolls. Electric current for heating the units 62 and 63 may be supplied thereto by the conductors 64. r

The cooperating rolls 56 and 5| are preferably formed of material having good heat-conducting characteristics, such as copper or brass, and by forming these rolls with large disk-like faces, it will be seen that they can be readily heated by radiant heat from the units 62 and 63. In this way the desired heating of the rolls 56 and 5| can be obtained without encountering the difflculty of establishing electrical connections for rotatable members. As shown in Fig. .8, the insulating body 6| is slidable along the

bars

54 and 55 so that the heating device 66 will be adjustable therealong as well as the roll-carrying

brackets

52 and 53. By adjusting the device 66 relative to the brackets the desired heating effect of the units 62 and 63 on the rolls 56 and 5| may be obtained and the heating device can then be clamped in the desired position of adjustment by the set screws 65.

The insulating body 6| of the heating device 66 may have a clearance opening 66' therein through which the guide bars 59 extend.

Reverting now to the drum 25 to which the strip |5 passes from the feed roll 46, it will be seen from Fig. l

in a counterclockwise direction the strip will exthat when this drum is rotated I tend around the outer surface of the drum and the sections or bags 2|, which are severed from,

the strip, will be carried by the drum to the opening 36 and discharged therethrough. The drum may be of any construction suitable for the accomplishment of the desired purpose, such as the construction the drawings. As shown in Fig. 4,'the drum may comprise axially spaced end plates or heads 66 and 69 which are formed of suitable electrically insulating material such as Transite" and which may be pinned or otherwise secured to the shaft 32. A cylindrical facing 16, formed of insulating sheet material and havingcircumferentially spaced axially extending slots 1| therein, is'secured to the heads 68 and 69. The facing 16 may be formed as a continuous sheet of such material wrapped around the heads and having the slots-1|. formed therein, or, if desired, it may be formed by mounting arcuate sections of the insulating sheet material on the heads with the edges of the adjacent sections spaced apart to form the slots 1|. For reinforcing the drum and providing additional support for the facing 16, we may mount an intermediate head 12 on the shaft 32 at a point substantially midway between the heads 68 and 69.

The slots 1| of the drum facing 16 are located thereon at distances spaced to correspond with the width desired for the bags 2| to be formed and heating and severing elements 13 disposed in or adjacent these slots act on terial and sever the same transversely along the lines or areas l3. These heating elements may be of any appropriate form, for example,'they may be wires or bars which are heated by the passage of electric current therethrough. For mounting these wires on the vide a circumferential series of plates 14 on the head 68 and another circumferential series of plates 15 on the opposite head 69, the plates of the latter series being in offset or staggered relation to the plates of the head 66. The plates 14 and 15 may be secured to the respective heads 66 and 69 of the drum by means of suitable studs or screws 16. Each of the plates 14 and 15 carries a pair of clamping devices 11 which are spaced apart the same arcuate distance as the slots 1| of the drum face. The plates 14 and 15 are mounted on the drum heads 66 and 69 with the clamping device 11 in axial alignment with the slots 1| so that the ends of the heating elements 13 may be gripped and held by these devices.

. As shown in Figs. and 11, each of the clamping devices 11 may comprise a slotted part 16 which may be an integral extension of the plate 14 (or plate and a pair of aligned screws 19 and66 extending into the slot with their ends in opposed relation. The ends of the heating element 13 extend into the slots of extension parts 11' and are gripped by the opposed ends of the screws 19 and 86. The radial position of the elements 13 with respect to the drum surface can be varied or adjusted by adjustmentof the cooperating screws 19 and 66. It will also be seen that which we have illustrated inthe strip |5 during the rotation of the drum to soften the sheet ma-.

drum we may. prov when replacement of the heating elements 13 is 1 necessary or desirable, the old elements can be easily removed by loosening the screws 19 and new elements can be quickly substituted and clamped in place by tightening of these screws.

The plates 14 at one end of the drum 25 can all be of similar or identical construction. The plates 15 at the other end of the drum can also be means of the conductors 82 and 83.

of similar construction, but one of thelatter plates, such as the plate 15, is formed of spaced sections so that a desired electrical circuit can be maintained through the heating elements 13. It will be seen from the staggered arrangement of the plates I5 with respect to the plates 14, that each of the elements I3 has one end thereof connected with one of the plates 15 and its opposite end connected with one of the plates 14. By reason of this arrangement the elements 13 are electrically connected in series with each other and the two sections of the plate I5 form the terminals of this series circuit.

For establishing electrical connection with the elements I3, we may provide one of the drum heads, for example, the head 68, with a pair of collector'rings- 8| and 8| which are connected respectively with the sections of the plate Li by Electric contact may be made with the collector rings 8| and 8| during rotation of the drum 25 by means of

suitable brushes

84 and 85 which are carried by a brush holder 86 and bear against these rings. A pair of

conductors

81 and 88 leading from a suitable source of current are connected with the

brushes

84 and 85.

For pressing the strip I5 against the face of the drum 25 and against the heating elements 13, we

, create a fluid pressure differential between opposite sides of the strip. This pressure differential is obtained by creating a pressure in the chamber 24 of the frame 23 such as by forcing air into this chamber through the conduit 90. The air pressure in the chamber 24 presses the strip against the drum surface so that when the drum is driven by the pulley 32 it will carry the strip along with it and thus advance the material toward the opening 30. The air pressure in this chamber also presses the strip against the heating elements I3, and upon softening of the thermoplastic material, the pressure on the strip causes the same to be severed by the elements. The severing of the strip at these points permits the severed edges of the sections 20 to be deflected towards the inside of the drum by a flow of air from the chamber 24 into the drum through the slots 1|. Interference between these inwardly deflected edges and the drum structure may be prevented by providing the drum heads 68, 69 and I2 with clearance recesses 9| adjacent the heating elements I3. This flow of air through the slots serves to cool and harden the severed edges of the material and, in addition, it will be seen that the inwardly deflected edges will assist in holding the newly formed bags in place on the drum until they arrive at the opening 30.

The flow of air into the drum from the chamber 24 creates a pressure in the drum which may be 7 lower than the pressure in the chamber but which bags delivered at the opening 30 may be collected by any suitable means such as by providing a container 192 at this point to catch the bags as they are discharged. from the drum.

To avoid sparking or short-circuiting at the heating element I3, we may construct the feed roll 40 of suitable insulating material and may also provide laterally extending insulating strips 93 and 94 on the frame 23 at the upper and lower edges of the opening 30.

In addition to the slots II of the drum facing "I we may also provide relatively numerous perforations 95 in the drum facing to enable the pressure in the chamber 24 to more firmly press the strip I against the drum surface. In some conditions of operation these perforations may not be needed and can be omitted.

Instead of forming the heating elements I3 of the drum as individual round wires we may employ other specific forms of heating elements such as bars 98 of substantially triangular cross-section, as shown in Fig. 12, or we may employ heating elements consisting of a group of wires as shown in Fig. 13. When the heating element consists of a group of wires, as shown in this instance. the center wire 91 is heated to a temperature high enough to sever the sheet material 98, and the wires 99 may be heated to a temperature only high enough to soften or fuse the sheet material;

In constructing the frame 23 of the machine it may be desirable to provide for ready access to the chamber 24 and to the drum 25 and for this purpose we may provide hinged or removable doors I00 and IM in the rear and top walls of the chamber. One or both of these doors may be provided with windows for observing the operation of the drum during a production run.

Instead of using the above-mentioned pair of cooperating pressure and sealing members 50 and 5| for joining the layers I6 and II of the strip I5, we may provide sealing means of the form shown in Figs. 14 and 15. In this latter arrangement we provide a sealing and joiningrnember I03 past which the strip I5, comprising overlying layers I6 and I1, is pulled by the feed roll 40 and 4|.

The sealing member I03 may comprise an arm I04 and a heating element in the form of a shoe I05 against which the strip I5 is pressed by reason of the tension therein. The shoe I05 may be formed of resistance ribbon bent to the desired shape and mounted on .an insulating block I08 which is carried by the arm I04. Electric conductors I01 and I08 may be connected with the shoe for supplying heating current thereto. The arm I04 may be mounted on the laterally extending bar 54 so as to provide for both lateral and pivotal adjustment and may be clamped in the desired adjustment by means of the set screw I09.

From the foregoing description and accompanying drawings it will now be readily seen that we have provided an improved method and apparatus for rapidly and economically producing bags or envelopes and like articles from Pliofilm or other sheet material. It will also be seen that we have provided a novel method of operating on sheet material in which a pressure differential is utilized for pressing the material against elements of a rotary member and in which a pressure differential may also. be used for dislodging the articles.

While we have illustrated and described the method and apparatus of our invention in a somewhat detailed manner it should be understood, however, that we do not wish to be limited to the precise steps of procedure and forms of apparatus herein disclosed, but regard our invention as including such changes and modifications as do not constitute a departure from the spirit of the invention and the scope of the appended claims.

Having thus described our invention, we claim:

1. In a method of operating on thin thermoimposed strips of such material: and a machine element'intocontact witheach other by traveling movement, and creating a" fluid pressure diilerential between opposite sides oi'the m'aterialfior pressing the material against the machine elementl 2. In a method of operating on thin sheet material, the steps of bringing such material and a machine element into contact with each other, and creating a fluid pressure differential between opposite sides of the material first with a resultant Iorce acting to press the material against said element and then with a resultant force acting to move the material away from the element.

3. In a method of making bags by severing thin thermoplastic sheet material or the like and sealing the severed edges, the steps of bringing superimposed layers oi such material and a heating and severing element into contact with each other, and creating a fluid pressure diflerential between opposite sides of the material for pressing the material against the element.

4. In a continuous method of making bags from thin thermoplastic sheet material or the like comprising, leading superimposed layers of such material in strip form over a rotary member. having spaced heating and severing elements thereon, and creating a fluid pressure differential between opposite sides of the material for pressing successive portions thereof against said elements as the strip is advanced.

5. In a continuous method of making bags from thin thermoplastic sheet material or the like comprising, leading superimposed layers of such material in strip form over a rotary member having spaced heating and severing elements thereon, 'and creating a pressure differential between opposite sides of the material first with a resultant force acting to press successive portions against said member and elements as the strip is advanced and then with a resultant force acting to dislodge severed sections of the strip from said rotary member.

6. In apparatus of the character described, the combination of a rotary member having spaced heating elements and adapted to be driven for advancing strip material in overlying relation to said heating elements, and means providing for the flow of air under pressure toward said member during one portion of its travel and away from said member during another portion of its travel whereby the material is pressed against said elements during said one portion of the travel of the rotary member and the severed sections are dislodged from the rotary member during said other portion of its travel.

7. In apparatus of the character described, the combination of a rotary member having spaced heating elements and adapted to be driven for advancing strip material in overlying relation to said heating elements, a housing at least partially surrounding said rotary member, and means for supplying air under pressure to said housing for pressing the material against said elements.

8. In apparatus of the character described the combination of a housing forming a pressure chamber having an opening therein, a hollow rotary member having peripheral openings and spaced heating and severing elements, said member being arranged to operate in said opening with strip material to be severed overlying said elements, and means for supplying air .Ior pressing the material toward that portion of the rotary member which extends into the chamber and tor dislodging severed sections from the portion which is exposed by the chamber-opening.

9. In a machine for the continuous production of bags from thin thermoplastic sheet material or the like, a hollow frame providing a pressure chamber with an opening to atmosphere, adrum having circumferentially spaced openings and heating elements in or adjacent such openings, means mounting said drum for rotation in said chamber opening for advancing superimposed layers of such material in overlaying relation to said elements, and means for creating a. superatmospheric pressure in said chamber and drum for pressing the material against said elements and for dislodging the bags from the drum.

10. In apparatus for operating on thin sheet material, a rotary member, means for causing the sheet material and said rotary member to be brought adjacent each other, aplurality of heating elements spaced around the periphery oi! said rotary member for operating on the sheet material, and means mounting said elements on the rotary member and providing for adjustment of the elements as to their distance from a. common rotation axis.

11. In apparatus of the character described, a rotatable drum having peripherally spaced elements for operating on thin sheet material, means for supporting a roll of such sheet material adjacent said drum, a hollow structure at least partially surrounding said drum, means for supplying fluid pressure to said hollow structure for pressing the sheet material against said drum and elements, and means for driving the drum to unwind the sheet material from said roll.

12. In apparatus of the character described, a. rotatable drum having peripherally spaced elements for operating on thin sheet material, means for supporting a roll of such sheet material adjacent said drum, a hollow structure atleastpartially surrounding said drum, means for supplying fluid pressure to said hollow structure for pressing the sheet material against said drum and elements, means for driving the drum to unwind the sheet material from said roll, and means adapted to act on the sheet material at a point between said supporting means and drum comprising cooperating members for applying heat and pressure to the sheet material.

13. In apparatus for operating on sheet material, the combination of a rotary member having spaced elements adapted to be brought into contact with the sheet material and heated sufflciently to sever the same, means for heating said elements, and means for causing fluid pressure to act on the material for pressing the same against said elements. Y

14. In apparatus of the character described the combination of a rotary member having spaced heating elements and adapted to be' driven for advancing strip material in overlying relation to said heating elements, means for driving said rotary member, means for electrically heating said elements sufliciently to sever said material, and means for causing fluid pressure to act on the material for pressing the same against said elements.

NORMAN H. NYE. RALPH L. PENN.

RALPH W. PENN.