US3419200A

US3419200A - Fabric creasing and pressing machine

Info

Publication number: US3419200A
Application number: US586469A
Authority: US
Inventors: Salvatore J Aramini
Original assignee: TRUFAST PRODUCTS Inc
Current assignee: TRUFAST PRODUCTS Inc
Priority date: 1966-10-13
Filing date: 1966-10-13
Publication date: 1968-12-31
Anticipated expiration: 1985-12-31

Description

Dec. 31, 1968 s. J. ARAMINI 3,419,200

FABRIC CREASING AND PRESSING MACHINE Filed oct. 13. 1966 United States Patent 3,419,200 FABRIC CREASING AND PRESSING MACHINE Salvatore J. Aramini, Merrick, N.Y., assigner to Trufast Products Inc., a corporation of New York Filed Oct. 13, 1966, Ser. No. 586,469 11 Claims. (Cl. 223-38) ABSTRACT F THE DISCLOSURE A fabric blank creasing and pressing machine including a frame having an aperture for receiving the blank and clamping means for clamping the blank in place. Folding means is provided for folding the blank and pressing means for heating and pressing the folded blank. Moving means is provided for operating the folding and pressing means and a timer, responsive to the operation of the folding means, is provided t0 maintain the elements in their respective operating positions for a preselected interval of time.

This invention relates to an improved fabric creasing machine, and more particularly to a machine which automatically shapes, creases and presses fabrics.

A number of machines have been proposed to meet the ever increasing demand for machines of the type which crease and press fabrics. Such machines are used, for example, to quickly and automatically form patch pockets. Present patch pocket machines, however, all have several nonautomatic functions which require the attention of an operator. For example, some machines require the operator to insert, fold and press the fabric blank until a satisfactory shape is obtained. With these Inachines, the operator is not only restricted to one machine, but also is under constant physical strain.

Still other machines require the operator to clamp and fold the fabric blank and in addition depress a treadle to initiate a pressing operation. In some of these machines, the operator must keep the treadle depressed during an entire pressing cycle; in others, the operator must depress the treadle for a portion of the cycle and lock the treadle in position to activate a holding cam. All the present machines have a common disadvantage, however, in that the operator must perform a plurality of time consuming operations which of necessity require the operators full attention.

It is often additionally desirable to vary the pressing time in order to obtain the best possible crease for each type of fabric blank used, and to maintain this same pressing time for a plurality of opeations on the same type fabric blank. Present machines depend on the operator to estimate the pressing time in each operation, thus making it diflicult to obtain the same results for a plurality of operations by even a skilled operator. Automatic repetition of the pressing time would permit using less skilled operators while still achieving the best possible crease each time.

An object of the present invention, therefore, is to provide a machine which automatically creases and presses fabrics.

Another object is to provide a fabric creasing and pressing machine which is simple and easy to operate.

Still another object of this invention is to provide a fabric creasing and pressing machine in which many sequential tasks, heretofore performed manually, are performed automatically.

A still further object is to provide a fabric creasing machine which is eicient and economical in operation.

Yet another object is to provide a fabric creasing machine having a presettable pressing time.

In accordance with the invention a fabric blank creasing machine comprises a frame having an aperture suit- 3,419,200 Patented Dec. 3l, 1968 able for receiving the fabric blank to be creased. A first means is provided for clamping the fabric blank to be creased. This first means is connected to the frame member and movable over the aperture. A second means is provided for folding the fabric blank. This second means is horizontally movably mounted to the frame member. A fabric heating and pressing member is mounted t0 the frame and can be moved within the aperture to engage the fabric blank. A third means connected to the frame is also provided for slideably moving the second means into a position over the aperture for folding the fabric blank and for vertically moving the heating and pressing member within the fabric blank. The fabric creasing and pressing machine finally `comprises a fourth means connected to the frame and responsive to the movement of the second means for maintaining the heating and pressing element in the aperture for a predetermined time while the second means is positioned over the aperture so that a folding and creasing action is applied to the fabric blank for the predetermined time.

For a `better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawing in which similar reference characters are used to refer to related elements.

Referring to the drawing:

FIG. 1 is a top view of a machine of the present invention;

FIG. 2 is a cross-sectional view of the machine, taken along line 2-2 of FIG. 1, looking in the direction of the arrows, showing the working relationship of the parts; and

FIG. 3 is a partial side view of the machine, taken along lines 3 3 of FIG. 2, looking in the direction of the arrows.

Description of the apparatus shown in the drawing Referring to the three views of the fabric creasing machine, there is shown a supporting frame 10, which may be box-like in shape and fabricated of any rigid material. The frame 10 is constructed so that it may readily be mounted on a Work bench or table top. The top of the frame 10 contains an opening 11 whose shape and purpose will ysubsequently be described. An aperture 12, which is of suitable size and shape to receive the fabric blank to be creased is also located in the top of the frame 10, as shown in FIG. 1. The aperture 12 may be rectangular in shape. A fabric blank heating and pressing member 13 fits loosely within the aperture 12 in a substantially horizontal and at position and is movable upward therethrough. The fabric heating and pressing member 13 can be a rectangularly shaped plate to conform, as shown here, to the shape of the aperture 12. The heating and pressing member 13 includes a, means for heating such as an electrical heating element (not shown) or other means commonly known in the art.

A means for clamping the fabric blank, shown as a thin clamping plate 14, which can be constructed of a material that does not warp or distend when heated, is placed over and clamps the fabric blank against the heating and pressing member 13. The clamping plate 14 is somewhat smaller than the heating and pressing member 13, as indicated by double arrowheads 17e. The clamping plate 14 is attached to the underside of a pivot arm 15 which is pivotably mounted on the rear of the frame 10 and may be pivoted manually. The pivot arm 15 has a weight 16 attached thereto at one end toward the rear of the frame 10 to urge the pivot arm 15 and clamping plate 14 attached thereto upwardly and away from the top of the frame 10.

A means for folding the fabric blank, shown as horizontal at

plates

17a and 17b are slideably mounted on the top of frame so as to move in the horizontal plane towards and away from each other and over the aperture 12 of the frame 10. The

flat plates

17a and 17b are also resiliently biased away from each other by springs 18a and 18h, respectively. The other ends of

springs

18a and 18b are connected to the top of the frame 10.

The flat plate 17a contains slots 19a and 19e which enclose studs 20a and 20c, respectively. Similarly, the flat plate 17b contains slots 191; and

19d enclosing studs

20b and 20d, respectively. These studs are themselves mounted on the top of the frame 10, thereby causing the flat plate 17a to be guided in a fixed horizontal path along the direction of the slots 19a and 19C and the flat plate 17b to be guided in a fixed horizontal path along the direction of the slots 19h and 19d. Movement of the at plate 17a and the at plate 17b toward each other and into operating position over the aperture 12 folds the edges of the fabric blank and locks the clamping plate 14 into operating position on the fabric. The at

plates

17a and 17b lock the clamping plate 14 by moving into a position over the edges and top of the clamping plate 14.

A means for moving the folding means over the aperture and the heating and pressing member into the aperture, shown as including pusher plate 21, is slideably mounted to the top of the frame 10 in the same horizontal plane as the

folding plates

17a and 17b. The pusher plate 21 has two triangularly shaped feet, one at each end facing both the folding plate 17a and the folding plate 17b. The triangular shaped feet are located adjacent to the folding plate 17a and the folding plate 17b when the pusher plate 21 is in a rest position. The pusher plate 21 is adapted to move toward and away from the folding plate 17a and the folding plate 17b, causing the triangular feet at each end to cam the folding plate 17a and the folding plate 17b over the aperture 12. The pusher plate 21 is resiliently `biased by a spring 22 which has one end connected to the frame 10 to return the pusher plate 21 to the rest position. The pusher plate 21 is guided toward and away from the

folding plates

17a and 17b by guides 23a and 23h. The

guides

23a and 23b are mounted at opposite edges of the top of the frame 10, and alongside the triangular feet of the pusher plate 21. The pusher plate 21 has a depending rod-like projection 24 which protrudes through the opening 11 in the top of frame 10. The opening 11 is of sufficient size to allow the pusher plate 21 and the rod-like projection 24 to move without restraint for the entire camming movement.

The moving means is further shown to include a slider which is horizontally movable in the same direction as the pusher plate 21, and slideably mounted within and below the top of the frame 10, The slider 25 includes an upstanding post 26, perpendicularly mounted on one end of the slider 25 which is positioned to contact the rodlike projection 24 of the pusher plate 21. The slider 25 has an opening 27 in its center. A roller bearing 28 is rotatably mounted on the slider 25 at the end of the channel 27 farthest away from the rod-like leg 26, the axis of the roller bearing 28 being transversely located relative to the direction of movement of the slider 25 and the pusher plate 21. The slider 25 is connected to the frame 10 for sliding movement with respect thereto by a bracket 29. More specifically, the bracket 29 includes a rear portion 29a and a forward portion 29h. Portion 29a as shown in FIGS. 2 and 3, includes a transversely extending member 29C, the ends of which are connected to the side walls of the frame 10. Connected between the members 29C and 29d, to the undersurfaces thereof, are transversely spaced longitudinally extending rods 29e and 29f. Connected to the bottom surfaces of

rods

29e and 29j, in opposed relationship to the member 29C is a transversely extending section 29g. Likewise, connected to the undersurface of the rods 29e and 29], in opposed relationship to the member 29d, is a transversely extending section 29h.

Provided in the member 29.0 and Section 29s are 0P- posed recesses which, together with the

rods

29e and 29j, define a through aperture 29j. Similarly, provided in the member 29d and section 29h are opposed recesses which, together with the rods 29e and 29], define a through aperture 29k. The

apertures

29k and 29j slidingly receive the slider 25 through so that slider 25 may move in the directions indicated by double arrowhead with respect to frame 10.

An angle block 31 is attached to a means for maintaining the heating and pressing member 13 in the aperture, which includes a means for moving the angle block upward, a means for indicating when the folding means has moved to a predetermined position, and a means for causing the angle block moving means to retract the angle block 31. In particular, the angle block 31 is shown attached to the means for moving the angle block upward, depicted as including a piston rod 32 of an air cylinder 33. The air cylinder 33 is double-acting and has an extending side and a retracting side. The double-acting air cylinder 33 is fixedly mounted to the frame 10 by a mounting fixture 34 so that the rod 32 can move in a vertical direction. The movement of the rod 32 also causes the angle block 31 to move up and down in a vertical direction. The angle `block 31 has an angular shape so that vertical upward movement of the angle block 31 into the channel 27 contacts roller bearing 28, causing the roller bearing 28 and the slider 25 to move toward the rear of frame 10. The rearward movement of the slider 25 causes the post 26 to engage and move the rod-like projection 24 of the pusher plate 21, thereby causing the pusher plate 21 to move in the same horizontal direction as the slider 25.

The means for moving the folding means includes a lever 35 which is pivotably mounted on the bracket 29. To be more specific, the bracket 29 includes upstanding opposed posts which are connected to

rods

29e and 29j, respectively. Only the post 291 is shown in FIG. 2 for purposes of clarity, it being understood that the other post is located opposite thereto, A pivot 82 extends between these posts and rotatably through a bore 84 in the arm 35 to mount it for pivotable movement. Additionally, a spring 30 is connected between a stud 25a on slider 25 and the post 291 of the bracket 29 to bias the slider t0 a forward or rest position. The other end of arm 35 extends over and beyond the top point of the angle block 31. The lever arm 35 has a tooth 36 protruding from the top thereof and located directly below the heating and pressing member 13. The angle block 31 is constructed so that when the camming action which moves the slider 25 is complete, the angle block 31 continues to move in an upward direction, contacting the lever arm 35 and pivoting the protruding tooth 36 up against the heating and pressing member 13 to apply pressure thereto. Dur ing this time the angle block 31 maintains the slider 25 in operational position.

When pressure is not `being applied, the heating and pressing member 13 is held in position by

screws

37a, 37b, 37e` and 37d;

screws

37a, 37b being connected t0 the member 29d and screws 38C and 37d being connected to member 29C.

Screws

37a, 37b, 37e1 and 37d are mounted at each corner of the heating and pressing element 13.

A source of electrical power, not shown, is connected to a start switch 38, which is a manual ON-OFF switch and is mounted on the pivot arm 15. A set of start wires 39, connected to the start switch 38y is also connected to the means for moving the angle block upward, which is shown to further include a solenoid valve 40 mounted to the frame 10 which, upon energization of the start switch 38, allows air to enter the air cylinder 33, thereby causing the piston rod 32 and the angle block 31 attached thereto to move the slider 25.

The means for indicating when the folding means has moved to a predetermined position, shown as normally open push button Contact switch 41 is mounted on the bracket 29b so as to be contact and energized by the post 26 of the slider 25, when the slider 25 reaches operational position. That is, post 26 is provided with a rearward extension 26a which is in spaced replationship to the botton of switch 41 when the slider 25 is in the rest position (the position shown in FIG. 2). However, when slider 25 moves rearwardly, the extension 26a contacts and depresses the button to close the switch. Upon energization of the contact switch 41, a means for causing the means for moving the angle block upward to retract the angle block, shown as a variable timer 42 mounted on the front of the frame 10, is activated through a set of timer wires 43a. After a set period of time, the timer 42, which is also connected to the solenoid valve 40 by a set of timer wires 43b, deactivates the solenoid valve 40 to switch the air from the extending side to the retracting side of the double-acting air clyinder 33, which retracts the shaft 32.

Operation of the apparatus shown in the drawing The fabric blank to be creased is placed over the aperture 12. Pivot arm is then pivoted downward by the operator and clamping plate 14 is thereby depressed into a position directly over aperture 12 contacting the fabric blank placed in the aperture 12. The clamping plate 14 iS somewhat smaller than the fabric blank so that the edges of the fabric plank protrude over the edges of the clamping plate 14 when the clamping plate is in the depressed position and clamped over the fabric blank. The start switch 38 is then energized. In the embodiment shown in the drawing, the start switch 38 is manually energized, however, the start switch 38 may also be positioned such that energization occurs automatically when the clamping plate 14 is depressed over the aperture to clamp the fabric.

Energization of the start switch 38 activates the solenoid valve 40. This permits compressed air to enter the double-acting air cylinder 33, causing the piston rod 32 and the angle block 31 connected thereto, to move upward. The angle block 31 is so shaped that upward movement there-of through the channel 27 applies pressure to the roller bearing 28, causing the slider to slide horizontally until the slider 25 contact moves into operational position to energize the contact switch 41. As the slider 25 moves, the pusher plates 21 is caused to slide in the same horizontal direction to contact the horizontal

flat plates

17a, 17b, thereby moving both flat plates into operating position to fold the edges of the fabric and lock the clamping plate 14 into position by engaging over the edges thereof.

The contact switch 41 is so positioned that when the slider 25 energizes the contact switch 41, the slider 25 has moved a sucient distance so that the at

plates

17a and 17b are already in operating position engaged over the fabric. The angle block 31 is so shaped that slider 25 is moved only a sufficient distance to energize the contact switch 41 and the subsequent continued upward motion of the angle block 31 no longer moves the slider 25, but merely maintains the slider 25 in a fixed position. However, as the angle block 31 continues to move upward, the lever arm 35 is contacted and the protruding tooth 36 thereof is pivoted upward against the heating and pressing element 13, causing suiiicient pressure to be applied to heating and pressing member 13 to crease and press the fabric. It is possible to omit the lever arm 35 by allowing the angle block 31 to contact the heating and pressing member 13, thereby applying direct pressure thereto to crease and press the fabric.

Energizing the contact switch 41 activates the variable timer 42 which may be preset to a predetermined desired time delay by an operator. After the predetermined time has elapsed, the variable timer 42 causes the solenoid valve to switch the supply of compressed air to the retracting side of the double-acting air cylinder 33, thereby retracting shaft 32, and also retracting the angle block 31 which is connected thereto. The amount of time to which the variable timer 42 is preset in effect determines the amount of time angle block 31 can continue to move upward, and therefore the length of time pressure is applied via the protruding tooth 36 of the lever arm 35 to the heating and pressing member 13. The variable timer 42 can be preset to whichever time provides the best creasing and pressing of the fabric.

When the angle block 31 is retracted, no longer holding the slider 25 in position, the slider 25, the pusher plate 21 and the

flat plates

17a and 17b, all being resiliently mounted, return to their respective initial positions. The clamping plate 14 is thereby unlocked and pivot arm 15, having the clamping plate 14 and the weight 16 mounted thereon, is automatically pivoted upward, allowing the creased fabric to be removed. The machine is now ready for insertion of the next fabric to be creased and pressed. Since the timer remains preset to the best possible creasing time, this time will now automatically be repeated in subsequent operations. The operator is merely required to p-lace the fabric in the machine, lower the pivot arm 15, and ensure that the start switch 38 is energized. No particular skill or talent is required. The variable timer 42 could even be preset by a more skilled operator who is now relieved by repeatedly operating the machine.

While there has been described what is at present considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications as fall within the spirit and scope of the invention.

What is claimed is:

1. A fabric blank creasing and pressing machine comprising:

`a frame having an aperture suitable for receiving a fabric blank to be creased;

first means, connected to the frame and movable over the aperture, for clamping the fabric blank to be creased;

second means, horizontally movably mounted to the frame, for folding the fabric blank;

`a fabric heating and pressing member mounted to the frame and movable within the aperture to engage said fabric blank;

third means connected to said frame for slidably moving the second means into a position over the aperture for folding the fabric blank and for vertically moving the heating and pressing member within the aperture;

and fourth means connected to said frame and responsive to the movement of said second means for maintaining said heating and pressing member in the aperture for a predetermined time while said second means is positioned over the aperture so that a folding and creasing action is applied to the fabric blank for the predetermined time.

2. A machine as described in claim 1, wherein the first means comprises a thin metal clamping plate pivotably mounted to the frame.

3. A machine as described in claim 2, wherein the second means comprises a plurality of horizontal at plates slideably and resiliently mounted to the top of the frame and horizontally movable toward and away from each other and over the aperture to lock the clamping plate in operating position by moving over the edges and top thereof.

4. A fabric blank creasing and pressing machine cornprising: a frame having an aperture suitable for receiving the fabric blank to be creased; first means, connected to the frame and movable over the aperture, for clamping the fabric blank to be creased; second means, horizontally movably mounted to the frame, for folding the fabric blank; a fabric heating and pressing member mounted to the frame and movable within the aperture to engage said fabric blank; third means connected to said frame for slideably moving the second means into position over the aperture for folding the fabric blank and for vertically moving the heating and pressing member within the aperture; and fourth means connected to said frame and responsive to the movement of said second means for maintaining said heating and pressing member in the aperture for a predetermined time while said second means is positioned over the aperture so that a folding and creasing action is applied to the fabric blank for the predetermined time, said third means comprising a pusher plate slideably and resiliently mounted to the frame in the same horizontal plane as the second means and protruding vertically downward through the frame; a slider resiliently and slideably mounted to the frame and projecting upward to contact the pusher plate; a lever arm pivotably mounted to the frame and located directly below the heating and pressing element; and a substantially vertically movable angle block for providing a camming action for moving the slider for causing the pusher plate to engage and move the second means into position over the `aperture and the fabric blank placed therein for folding the fabric blank and for pivoting the lever arm against the heating and pressing element for applying pressure thereto while the second means is positioned over the aperture.

5. A machine as described in claim 4, wherein the fourth means comprises a fifth means coupled to the angle block for moving the angle block upward in a substantially vertical direction for providing the camming action and for pivoting the lever arm; a sixth means responsive to the second means and coupled to the frame for indicating when the second means has moved to a predetermined position; and a seventh means coupled to the sixth means, for causing the fifth means to retract the angle block after a predetermined time for terminating the pressing operation.

6. A fabric blank creasing and pressing machine comprising: a frame having an aperture suitable for receiving the fabric blank to be creased; first means, connected to the frame and movable over the aperture, for clamping the fabric blank to be creased; second means, horizontally movably mounted to the frame, for folding the fabric blank; a fabric heating and pressing member mounted to the frame and movable within the aperture to engage said fabric blank; third means connected to said frame for slideably moving the second means into a position over the aperture for folding the fabric blank and for vertically moving the heating and pressing member within the aperture; and fourth means connected to said frame and responsive to the movement of said second means for maintaining said heating and pressing member in the aperture for a predetermined time while said second means is positioned over the aperture so that a folding and creasing action is applied to the fabric blank for the predetermined time, said third means comprising a pusher plate slideably and resiliently mounted to the frame in the same horizontal plane as the second means, and having a rod-like projection protruding vertically downward through an opening in the top of the frame, a slider resiliently and slideably mounted to the frame and having a rod-like leg projecting upward to contact the rod-like projection of the pusher plate, a lever arm pivotably mounted to the ame and located directly below the heating and pressing element, and a substantially vertically movable angle block for providing a camming action for moving the slider in a substantially horizontal plane for causing the 4pusher plate to engage and move the second means over the aperture, and for pivoting the lever arm against the heating and pressing element for applying pressure thereto while the second means is positioned over the aperture; and the fourth means comprises a fifth means coupled to the angle block for moving the angle block upward in a substantially vertical direction for providing the camming action and for pivoting the lever arm; a sixth means responsive to the second means and coupled to the frame for indicating when the second means has moved to a predetermined position, and a seventh means coupled to the sixth means for causing the fifth means to retract the angle block after a predetermined time for terminating the pressing operation.

7. A machine as described in claim 6, which additionally comprises a start switch coupled to the fifth means for activation thereof.

8. A machine as described in claim 6, wherein the fifth means comprises a double-acting air cylinder mounted to the frame and having a substantially vertically movable shaft connected to the angle block for movement thereof; and a solenoid valve supplied with compressed air and coupled to the double acting air cylinder for causing the shaft and the angle block coupled thereto to move upward to engage the slider and to move downward to retract the angle block and shaft.

9. A machine as described in claim 8, wherein the sixth means comprises a contact switch positioned within the frame and energized when the second means has moved to a predetermined position.

10. A machine as described in claim 9, wherein the seventh means comprises a timer coupled to and activated by the contact switch and coupled to the solenoid valve, for causing the solenoid valve to switch the compressed air to the retracting side of the double acting air cylinder after the predetermined time to retract the shaft and the angle block for terminating the pressing operation.

11. A fabric creasing and pressing machine comprisa frame having an aperture suitable for receiving the fabric blank to be creased;

a thin clamping plate pivotably mounted to the frame and movable over the aperture for clamping the fabric blank to be creased;

a pair of horizontal fiat plates sildeably and resiliently mounted to the frame and horizontally movable toward and away from each other and over the aperture for folding the fabric blank to be creased and for locking the clamping plate in operating position by moving over the edges and top thereof;

a fabric heating and pressing member mounted to the frame and movable within the aperture to engage the fabric;

a pusher plate slideably and resiliently mounted to the frame in the same horizontal plane as the fiat plates and movable toward and away from the dat plates for camming said fiat plates over the aperture, and having a rod-like projection protruding vertically downward through an opening in the top of the frame, the opening being of suiiicient size for permitting the pusher plate to move 'without restraint for the entire camming movement;

a slider having a hollow channel therein and having a rod-like leg projecting upward in a vertical direction to contact the rod-like projection of the pusher plate, and resiliently and slideably mounted within and below the top of the frame, substantially horizontally movable in the same direction as the pusher plate;

a roller bearing rotatably mounted to the slider at the end of the channel farthest away from the rod-like leg, the axis of the roller bearing being traversely located to the direction of movement of the slider and the pusher plate;

a lever arm pivotably mounted on the inside of the frame and having a tooth protruding from the top thereof and located directly below the heating and pressing member;

an angle block movable up and down in a substantial- 1y vertical direction and having an angular shape for upward movement into the slider channel to contact the roller bearing and provide the camming action for moving the slider, the rod-like leg of the slider engaging the rod-like projection of the pusher plate, for causing the pusher plate to engage and position the folding plates over the aperture, the angle block upon continued movement upward, contacting and pivoting the lever arm up against the heating and pressing member to apply pressure thereto and also maintaining the folding plates over the aperture;

a double-acting air cylinder coupled to the frame and having a substantially vertically movable shaft coupled to the angle block for movement thereof;

a solenoid valve coupled to the double-acting air cylinder for activating the extending side of the cylinder to upwardly move the shaft and the angle block attached thereto, and for subsequently activating the retracting side of the cylinder after a predetermined time for retracting the angle block and the shaft;

a start switch coupled to the solenoid valve, for causing the valve to be activated;

and a timer coupled to and activated by the contact switch and coupled to the solenoid valve, for causing the solenoid valve to activate the retracting side of the double-acting air cylinder after the predetermined time for retracting the shaft and the angle block to permit the resiliently mounted slider, pusherplate and folding plates to return to their initial positions, thereby unlocking the clamping plate and terminating the pressing operation after the predetermined time.

References Cited UNITED STATES PATENTS 2,453,623 11/ 1948 Gilbert et al 223-38 2,609,129 9/1952 Goldberg 223-38 2,884,168 4/ 1959 Portera 223-38 3,093,275 6/1963 Silverman 223-38 3,112,847 12/1963 Brumby 223-38 X JORDAN FRANKLIN, Primary Examiner. 20 G. V. LARKIN, Assistant Examiner.