Sheet-cutting Mechanism

Abstract

A sheet-cutting mechanism which comprises a feed table having a stationary support portion and a tiltable support portion. The tiltable support is arranged to support the portion of the sheet to be cut off during the cutting operation, and thereafter it is tilted to an inclined position to cause the cutoff portion to slide off. The tiltable support is then returned to its normal feed position wherein it is in planar relation to the stationary portion of the feed table. The support is tilted to its inclined position and returned to its normal position by means of a cylinder and piston unit, which is controlled by valve means actuated in response to the movement of a member-forming part of the cutting mechanism.

Parent Case Text

This application is a continuation-in-part of my application for"Sheet Cutting Mechanism" filed July 19, 1968, Ser. No. 746,183, now abandoned.

Description

This invention relates to sheet-cutting mechanism, particularly to the means supporting the sheets during the cutting operation.

In cutting thin sheets, it is necessary to support the portions of the sheets to be cut off, for otherwise, the unsupported ends of the sheets tend to hang down or sag past the knife means. This condition results in unsatisfactory cutting action. Further, the ends of the sheets must be manipulated by operators to bring them to and in contact with the stop means which determines the size of the cutoff portions.

An object of this invention is to provide a tiltable support for supporting the portion of a sheet to be cut off during cutting operation, and thereafter tilt it to an inclined position to permit the cutoff portion to slide thereoff. After the cutoff portion clears the tiltable support, the support is moved back to its normal position wherein it forms a planar continuation of the feed table means.

Another object is to provide a tiltable support arrangement as described above, wherein the support is tilted into its several positions by a power actuator, preferably a pressure fluid motor.

A further object is to provide control means for the actuator, which means is operated in response to the operating movement of an element of the movable cutting mechanism to thereby synchronize the movement of the tiltable support with the cutting operation.

Another object is to provide a lever system between the tiltable support and the actuator whereby a rapid and positive tilting motion takes place.

These and other objects of the invention will be more readily understood by reference to the following detailed description of one specific embodiment thereof, when considered with the accompanying drawings, wherein:

FIG. 1 is a schematic side view of the cutting machine;

FIG. 2 is a side view partly schematic and partly in section showing a detailed view of the mounting and actuation of the tiltable support, and

FIG. 3 is a schematic view of a modified detail shown in FIG. 1.

Referring to FIG. 1, frame 1 supports sheet feed table 2 to which a conventional lower knife 3 is secured by any desired well-known means. An upper movable knife 4 is carried by a swinging arm structure 5 pivoted about a pivot point 6. Arm 5 is actuated by any desired means to move knife 4 towards knife 3 for cooperative cutting action with knife 3. A conventional holddown means 7 clamps worksheet 8, which is to be cut, securely against the feed table, as knife 4 descends and cuts the right or leading end of sheet 8 from the main body of the sheet resting on the feed table.

A stop 9 limits the feeding movement of sheet 8 and determines the size of the cutoff portion. Stop 9 is carried by a bracket 10 which is secured to arm 5. Stop 9 may be adjustably positioned along bracket 10 to obtain various sizes of cutoff portions. Any well-known clamping or securing means may be utilized to adjustably position stop 9 along bracket 10 and thereafter clamp the stop to the bracket.

Brackets 12 are secured along opposite edges of arm 5 by bolts 13. As illustrated in FIG. 2, each bracket 12 comprises a member having wall 14 and flange 15 at right angles thereto. Flange 15 has slot 16 cut therein through which bolts 13 extend. Each bracket 12 is adjustably secured to arm 5 by passing bolts 13 through slot 16 and securing the bolts in threaded openings 17 in arm 5. By loosening the bolts, opposed brackets 12 may be adjusted horizontally along arm 5 to new positions, and thereafter clamped thereto by tightening the bolts. The adjusting means may also be used to align both opposed brackets for proper pivotal support of a tiltable support bed, as will be described herebelow.

Secured to each wall 15 is a plate member 19, as by screw means 20 or by other means as for example, welding. Secured to each plate 19 is a vertically adjustable block member 22. Block 22 is provided with a plurality of vertical slots 23 through which bolts 24 extend. The bolts cooperate with threaded openings in plates 19 whereby the position of opposed blocks 22 may be vertically adjusted on plates 19, and thereafter clamped thereto by tightening bolts 24.

Each block 22 is integrally formed with, or has secured thereto, a depending portion 22a located near the cutting portion of table 2 for supporting the pivoted end of tiltable support structure 28. Support 28 forms a tiltable planar combination of the feed table in one of its positions and support the portion of the worksheet to be cut off prior to the cutting operation, that is, the portion between knife 3 and stop 9.

Support 28 comprises a structure formed by suitable frame members upon which transverse sheet support rollers 30 are mounted to facilitate the movement of sheet 8 supported thereon. The end of support 28 near the cutting region is pivotally supported in blocks 22a by a cross-shaft 32. Shaft 32 is transversely secured to support 28 with its opposite ends journaled in suitable openings in opposed aligned portions 22a of blocks 22. Thus, support 28 can tilt with respect to blocks 22 and table 2.

Brackets 34 are secured to the underside of support 28 at opposite sides thereof to provide journal supports for a transverse or cross-shaft 35, generally parallel to cross-shaft 32. At each end of shaft 35, that is, on opposite sides of support 28, an arm 36 is nonrotatably secured thereto. Each arm carries a roller 37 which rides in a horizontal guide or rail 38. Intermediate the ends of shaft 35 a lever 39 is nonrotatably secured thereto. As illustrated in FIG. 2, lever 39 is angularly offset from arm 36. Lever 39 is connected to an actuator which comprises pivoted cylinder 40 with a piston therein carrying piston rod 41. Piston rod 41 is pivotally connected to arm 39 by a pin means 42. The cylinder is pivotally connected to the bottom of support 28 by a pivot pin 44 passing through the cylinder end and a bracket 45 secured to the bottom of support 28.

The actuator tilts support 28 downwardly in response to the operating movement of either holddown 7, arm 5 or any other moving part of the mechanism carrying out the cutting cycle. While any well-known cylinder control arrangement may be provided, the illustrated embodiment is preferred.

Actuator means 40-41 may be a single-acting, spring return fluid motor controlled by an electrically operated three-way valve device 48. Valve 48 is connected to the rod end of cylinder 40 by pipe 49 (FIG. 1), whereby the cylinder may be connected to the pressure fluid supply to move the piston rod inwardly within the cylinder, that is, to the left, when the movable value member of device 48 is moved to its supply position. In the other position of the movable valve member, the cylinder end is connected to the exhaust vent and it permits the spring to move piston rod 41 outwardly. To regulate the speed of movement of the piston rod, throttle means 50 may be inserted in the supply or exhaust, or both.

Cylinder 40 may also be of the conventional double-acting type controlled by a conventional four-way valve, and thereby move the piston rod by pressure fluid in both directions.

The movable valve member of valve 48 is moved to its supply and exhaust positions by electric means, such as a solenoid, controlled by timing means 51. Means 51 is a conventional timer means which energizes the electrical-actuating means in valve 48, to move the valve member to one position, and hold it there for a certain time interval and thereafter deenergizes the actuating means to permit the valve member to return to its original position. There are many forms of such timer means commercially available and the specific form is merely a matter of selection.

The actuation of timer 51 is initiated by switch 52 which may be actuated in response to movement of hold down 7. Switch 52 is conventional and is operated by an adjustable operator means 54 secured to hold down 7. Means 54 comprises a mounting wall 55 having a slot 56 therein. A bolt 57 passing through the slot adjustably secures means 54 to hold down 7. Means 54 is provided with a cam element 58 which contacts switch 52 to energize it and initiate the operation of timer 51.

FIG. 3 illustrates a modification wherein switch-operating means 54 is secured to arm 5, and thus operation of cylinder 40 is responsive to movement of arm 5.

In operation, sheet 8 is fed forward, either manually or automatically, until its leading edge is stopped by stop 9. Thereafter, holddown 7 and arm 5 descend to hold the sheet down on table 2 while knives 4 and 3 perform their cutting operation. As holddown 7 moves down, cam element 58 actuates switch 52 which initiates the operation of timer 51.

At a proper and selected time of the operating cycle, timer 51 energizes the solenoid in valve 48 to move the valve member to the supply position wherein pressure fluid flows to pipe 49 and thereby cause inward movement of piston rod 41 to the left. As arm 5 descends the structure comprising means 14-19-22-22a-52 also descends a very small distance to prevent interference with the movement of knife 4. The timing is such that upon completion of the cutting operation, piston rod 41 initiates, or has somewhat initiated, its inward movement. The piston rod in its movement oscillates lever 39 clockwise, and through attached shaft 35, arms 36 also oscillate clockwise. In view of rollers 37 being guided in horizontal rails 38, the above movement causes tilting of support 28 about its pivoting or journaling axis in block portions 22a. The final inward positions of piston rod 41 and of the parts actuated thereby are illustrated in the dot-dash lines. As illustrated in FIG. 2, support 28 has been tilted to an inclined position wherein the cutoff portion of sheet 8 supported by rollers 30 may easily slide off into a proper container, or into a pile of cut sheet portions.

After a proper time interval which allows the cutoff portion to slide off tilted support 28, timer 51 deenergizes valve 48 to permit the valve member to assume the exhaust position. In that position, cylinder 40 is vented and piston rod 41 moves outwardly, or to the right, and thereby swings lever 39, arms 36 and support 28 anticlockwise to their initial positions, shown in full lines, wherein support 28 assumes its planar relation with feed table 2 to support the next portion of sheet 8 to be cut off.

If the modification of FIG. 3 is utilized, movement of arm 5 controls the tilting support 28.

While two sets of arms 36, rollers 37 and rails 38 are provided, one set on each side of the machine, it is obvious that the tilting of support 28 may be had by utilizing only one set of the above means.

By adjustably moving bracket 14 along arm 5, the supported pivoted end of support 28 may be moved horizontally with respect to knife 3. Thus, short pieces of sheet 8 may be cut off, the pieces falling through the adjustable space between knife 3 and the end of support 28 into a container. Obviously, during such cutting operation, the tilting of support 28 is not necessary and it may be inactivated by inserting a cutoff switch between switch 52 and timer 51, or means 54 may be manipulated so as to prevent its actuation of switch 52.

Blocks 22-22a and thereby the end of support 28 may be adjusted vertically by means of slots 23 and bolts 24. Thus, the end of support 28 may be vertically adjusted so that it does not interfere with sheet 8 or the descending elements on arm 5, as it is being tilted and the pivoted end moves in a clockwise direction.

While certain specific horizontal and vertical adjusting means are disclosed, it is apparent that other forms of adjusting means may be used to move blocks 22-22a horizontally and vertically relative to arm 5. Further, the adjusting means may be manually operated, or may be operated by well-known electric or pressure-fluid-actuating means.

In lieu of electric timer means, other commercially available nonelectric timing means may be used to control the supply and exhaust valve 48. For example, a self-contained timer valve may be used, wherein the valve is actuated to its positions by pressure fluid means, which means are operated by an adjustable throttle flow of fluid to obtain an adjustable time dwell for controlling the movement of the valve and thereby actuation of the piston rod.

Claims

Obviously many modifications and variations of the present invention may be made without departing from the scope of the appended claims.

What is claimed is:

1. A cutting mechanism for cutting off portions of stock material comprising, a feed table means for supporting said stock material, said table means having a stationary support portion and a tiltable portion forming a tiltable support which when in normal position forms a planar support continuation of the stationary support portion, stationary cutting means located intermediate the adjacent ends of said two table means portions, movable means carrying cutting means to cooperate with said stationary cutting means to cut off the portion of the stock material supported by said tiltable support, bearing means carried by said movable means for pivotally supporting the said adjacent end of the tiltable support, a cross-shaft pivotally secured to the midsection of the tiltable support, arm means nonrotatively secured at one end to said cross-shaft, guide means to guide the other end of the arm means in a generally horizontal path, a lever nonrotatively connected at one end to said cross-shaft, actuating means connected to said lever for moving said lever, cross-shaft and arms in opposite directions to thereby move the tiltable support from its normal position to an inclined position and thereafter move it back to its normal position.

2. Cutting mechanism as set forth in claim 1 wherein said actuator is a power actuator; first control means for controlling said power actuator to move said tiltable support to either of its positions, second control means for controlling the operation of said first control means, and operating means to initiate the functioning of said second control means in response to an operative movement of a member of the movable means.

3. A cutting mechanism as claimed in claim 2 wherein said member forms part of hold down means.

4. A cutting mechanism as claimed in claim 2 wherein said member is a swinging arm which forms part of said movable means and to which the cutting means are secured.

5. A cutting mechanism as claimed in claim 2 wherein the power actuator comprises relatively movable cylinder and piston elements, one of said elements being pivotally secured to said tiltable support at its said adjacent end and the other element being pivotally secured to said lever.

6. A cutting mechanism as claimed in claim 5 wherein said first control means comprises a valve device connected to the cylinder to selectively supply and exhaust pressure fluid thereto and therefrom, and wherein the second control means comprises a timing means for controlling the operation of the valve device in a selected time pattern.

7. A cutting mechanism as claimed in claim 6 wherein the valve device is an electrically actuated valve and the timer is of the electric type connected thereto, and wherein the operating means comprises a switch connected to the timer and a means adjustably mounted on said member for actuating said switch and thereby initiating the operation of the timer and valve device.

8. A cutting mechanism as claimed in claim 2 wherein the cross-shaft is pivotally secured to the bottom of the tiltable support; said arm means comprise two arms, one nonrotatively secured at one end of the cross-shaft, and the other arm nonrotatively secured to the other end of the shaft, on opposite sides of the tiltable support; and the lever is nonrotatively secured to the cross-shaft at a point intermediate said arms.

9. A cutting mechanism as claimed in claim 1 wherein the bearing means comprises; block means having openings therein to receive pivoted support means secured to said tiltable support; bracket means mounted on said movable means, and means for adjustably positioning said bracket means on said carrying means in a generally horizontal path to thereby vary the space between said adjacent ends of the stationary and tiltable portions of the feed table means, and means for securing said block means to said bracket means.

10. A cutting mechanism as claimed in claim 9 wherein said means for securing the block means to the bracket means comprises an adjusting means for adjustably securing said block means to said bracket means to vertically adjust the position of the block means on the movable means.

11. A cutting mechanism as claimed in claim 10 wherein the bearing means comprise one set of said bracket and block secured thereto positioned on one side of the feed table means, and a similar set of a bracket and block secured thereto positioned on the opposite side of the feed table means and aligned with said first set.