US3452630A - Hydraulic paper cutter and clamp - Google Patents

Description

INVENTOR JOHN A. MAL/W E- .3 BY dm,m w9m,wa

ATTORNEYS July 1, 1969 J. A. MALM 3,452,630-

HYDHAULIC PAPER CUTTER AND CLAMP Filed Oct. 10, 1966 INVENTOR JOHN A. MAL M ATIORNHS United States Patent U.S. Cl. 83380 9 Claims ABSTRACT OF THE DISCLOSURE A paper cutter having a self-contained power and control unit for operation of the cutter and clamp piston-cylinder assemblies which includes a reservoir with a pump therein, a motor and flywheel mounted on one side of the reservoir driving the pump, a pair of solenoid control valves mounted on the opposite side of the reservoir for controlling the cutter and clamp, respectively, such valves being interconnected by a line extending interiorly of the reservoir, and fluid lock means for the respective pistoncylinder assemblies which includes pilot operated check valves, the pilot lines of each being connected to the opposite ends of the piston-cylinder assemblies.

This invention relates generally as indicated to a paper cutter and more particularly to an improved drive and control system for an automatic hydraulic paper cutting machine.

Hydraulic paper cutting machines have well-known disadvantages in that they are oftentimes noisey, and the hydraulic system is subject to leakage. The latter problem may result in spoiled work, since oil or hydraulic fluid in the work area will damage the paper. Also, due to fluid leakage or seepage (when the machine is shut down for a fairly long period of time, such as a weekend, the seepage may permit the cutting edge of the knife to drop below the clamp in its elevated position. With the blade thus slightly projecting, an incautious operator may cut the back of his hand.

Attempts have been made to prop the blade in elevated position mechanically as seen, for example, in US. Letters Patent No. 3,111,876 to Rupp, but these require a multiplicity of parts which are subject to wear.

Moreover, hydraulic systems for paper cutting machines are notoriously diflicult to service since the components must generally be replaced individually, these being at the back of the machine beneath the table.

In spite of the disadvantages of hydraulic paper cutting machines, such machines are far superior to a manual or mechanical machine.

It is accordingly a principal object of the present invention to provide a hydraulic paper cutting machine not having some of the above-noted disadvantages.

Another principal object is the provision of a hydraulic paper cutting machine which incorporates in the hydraulic system safety locking devices precluding both the binder and knife from moving from their retracted position until the start of the cut cycle.

Another object is the provision of a hydraulic paper cutting machine having a compact easily serviceable power unit.

A further object is the provision of a hydraulic paper cutting machine which is not as subject to the disadvantages of leaking and noise as conventional machines.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a rear elevation of a machine in accordance with the present invention;

FIG. 2 is an enlarged fragmentary vertical section of the power drive unit seen in FIG. 1;

FIG. 3 is a schematic diagram of the hydraulic circuit in the neutral position;

FIG. 4 is a hydraulic schematic showing the system in its out condition; and

FIG. 5 is a similar hydraulic schematic showing the return condition.

Referring now to the annexed drawings and more particularly to FIG. 1, it will be seen that the illustrated paper cutting machine comprises a fabricated frame 1 which supports a table 2 extending both rearwardly and forwardly of the frame 1. The table 2 extends through the lower edge of a window 3 in the frame and the rear of such table pendantly supports drive motor 4 for back gauge 5. Movement of the back gauge toward and away from the viewer as seen in FIG. 1 is obtained by a screw extending longitudinally of the table 2 and driven by the transmission within housing 6.

A binder clamp B is mounted for vertical movement in gibs at each side of the window 3, and each end of the clamp B is supported on links as shown at 8 and 9 which are connected at their lower ends to cranks 10 and 11, respectively, mounted on transverse binder operating shaft 12 which is journalled at the opposite sides of the frame 1 as shown at 13 and 14.

Another crank 15 is secured to the shaft 12 to which is connected the rod 16 of binder piston-cylinder assembly 17. The blind end of such assembly is pivoted at 18 to bracket 19. In operation, the piston-cylinder assembly 17 is extended to rock the shaft 12 to pull down the links 8 and 9 to cause the binder B to move downwardly in its gibs to clamp a stack of paper on the table 2. The binder is mounted for vertical movement just to the rear of the knife K.

The knife K is removably adjustably mounted in a knife holder 21 which is supported by links 22 and 23 pivoted at 24 and 25, respectively, to the holder 21. The links 22 and 23 are also pivoted at 26 and 27, respectively, to the frame 1 above the window 3.

The link 22 extends beyond and upwardly from the pivot 24 with the knife holder 21 and the outer end is pivoted at 28 to the rod 29 of the knife piston-cylinder assembly 30. The blind end of the assembly 30 is pivoted at 31 to bracket 32 secured between gussets 33 in the vertically extending side housing 34. In operation, the assembly 30 is retracted to cause the knife to swing downwardly and to the right about the pivots 26 and 27.

The power unit for the assemblies 17 and 30 is mounted beneath the table 2 at the rear of the machine and is visible through access opening 36. Such power unit is shown generally at 37.

The power unit includes a sub-base 38 releasably connected to the main frame 1 so that the entire unit may readily be pulled from the machine. Supported on the subbase 38 is a tank 39 of generally rectangular configuration and on the interior wall thereof there is mounted a hydraulic pump 40 with the drive shaft 41 thereof projecting through the wall and being connected by coupling 42 to flywheel 43 mounted on the drive shaft 44 of the pump motor 45. The motor 45 is mounted on bracket 46 cantilevered from the exterior of the same wall on which the pump 40 is mounted.

On the opposite wall of the tank 39 there are mounted control valves 48 and 49 for the binder cylinder 17 and the knife cylinder 30, respectively. Such valves may be of the double solenoid, three position type with the valve 48 having a blocked center or neutral position while the valve 49 has an open center or neutral position.

As seen perhaps more clearly in FIGS. 2, 3, 4 and 5, the pump 40 includes an inlet 50 connected to filter 51 near the top of the tank 39 and the outlet 52 is connected to a pressure relief valve 53. From the outlet, the fluid pressure lines are connected to the valve 49 which is in turn connected to the valve 48 through the line 54. From the valve 49, lines 56 and 57 lead to the blind and rod end of the cylinder 17, while from the valve 48, lines 58 and 59 lead to the blind and rod ends of the cylinder 30. As seen in FIG. 1, pilot operated check valves 60 and 61 are provided in the lines 57 and 58, respectively, adjacent the rod end of the binder cylinder assembly 17 and the blind end of the knife cylinder assembly 30, respectively. The respective pilot lines 62 and 63 operating the valve 60 and 61 are connected across to the lines 56 and 59, respectively, leading to the blind end of the binder cylinder assembly 17 and the rod end of the knife cylinder assembly 30, respectively.

The purpose of the pilot operated check valves 60 and 61 adjacent to the blind end of the knife assembly 30 and the rod end of the binder assembly 17 is to lock the hydraulic fluid in such cylinders to preclude movement of the knife and binder downwardly unless and until hydraulic pressure is applied to the opposite ends of the respective assemblies. Accordingly, if fluid leaks or seeps from the lines 58 or 57 due to leakage about the pump, for example, the position of the knife or the position of the binder cannot change. It is only when the pressure is actuated by energization of the valves 48 and 49 that the knife or binder clamp can be moved.

In operation, the neutral position shown in FIG. 3 will first obtain. The operator then places a stack of papers on the table 2 and the back gauge is energized by the motor 4 to move the papers to the proper position which is determined by the operator by scale tape 65 driven through shaft 66 which moves across an illuminated gauge at the front of the machine. When the stack of papers is in the proper position, the cut cycle is ready to start. The operator will have at the front of the machine two widely positioned push buttons, thus requiring the presence of both hands, by which the cut cycle is started. The closing of these push buttons energizes the binder down solenoid of the valve 49 shifting the valve to the schematic position shown in FIG. 4 extending the pistoncylinder assembly 17. This brings the binder clamp B down upon the stack of papers behind the knife and it is again noted that the binder clamp cannot move until pressure is applied to the line 56 and through the pilot line 62 to open the pilot operated check valve 60. As soon as the pressure switch 67 dictates, the knife down solenoid of valve 48 will be energized shifting the valve to the position shown in FIG. 4. This then causes the knife cylinder assembly to retract bringing the knife down to the completion of its cutting stroke.

On the return stroke, the directional valves 48 and 49 will be shifted tothe position seen in FIG. 5 withpressure being supplied through the check valves 60 and 61 in lines 57 and 58 to the rod end of the cylinder assembly 17 and the blind end of the cylinder assembly 30. The extension of the cylinder assembly 30 elevates the knife to its retracted position and the safety pilot operated check valve 61 will preclude accidental retraction of the assembly and thus lowering of the knife due to fluid leakage.

It can now be seen that there is provided an improved hydraulic paper cutting machine which incorporates in the hydraulic system unique safety features. Moreover, the compact power unit provides an easily serviceable, less noisy drive which will maintain the working area of the machine much more free of hydraulic fluid or oil deposits.

Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. A hydraulic paper cutter including a knife cylinder assembly and a binder cylinder assembly, a tank having a bracket extending from one side thereof, a drive motor and flywheel mounted on said bracket, a pump in said tank driven by said motor flywheel, and valve means mounted on another side of said tank operative to control said knife and binder cylinder assemblies, said valve means comprising a pair of directional valves operative to supply hydraulic pressure to the opposite ends of said knife and binder cylinder assemblies.

2. A paper cutter is set forth in claim 1 including a pilot operated check valve in the hydraulic line connected to the blind end of said knife cylinder assembly.

3. A paper cutter as set forth in claim 2 wherein the pilot line operating said pilot operated check valve is connected to the rod end of said knife cylinder assembly.

4. A hydraulic paper cutter as set forth in claim 1 including a filter and relief valve in said tank as well as plumbing connections between said pump and valves whereby to minimize fluid leakage.

5. A hydraulic paper cutter including a knife cylinder assembly and a binder cylinder assembly, a tank having a bracket extending from one side thereof, a drive motor and flywheel mounted on said bracket, a pump in said tank driven by said motor flywheel, valve means mounted on another side of said tank operative to control said knife and binder cylinder assemblies, and pilot operated check valves mounted on said knife and binder cylinder assemblies operative to preclude movement thereof prior to actuation of said valves.

6. A hydraulic paper cutter as set forth in claim 5 wherein the pilot operated check valve is connected to the rod end of the binder cylinder assembly and to the blind end of the knife cylinder assembly.

7. A hydraulic paper cutter including a knife, a pistoncylinder assembly operatively connected to said knife, a binder, a piston-cylinder assembly operatively connected to said binder, valve means operative to control the movement of said piston-cylinder assemblies, and fluid lock means between said valve means and said pistoncylinder assemblies operative to preclude movement of said knife or binder toward the work without actuation of said valve means, said fluid lock means comprising pilot operated check valves for the respective pistoncylinder assemblies, the pilot lines of the respective check valves being connected to the opposite ends of said piston-cylinder assemblies.

8. A hydraulic paper cutter as set forth in claim 7 including a power unit for said piston-cylinder assemblies comprising a tank, a drive motor and flywheel mounted on one side of said tank, a pump in said tank driven by said motor and flywheel, said valve means being mounted on the opposite side of said tank.

9. A hydraulic paper cutter as set forth in claim 8 including a filter and relief valve in said tank as well as the plumbing connections between said pump and valves whereby to minimize fluid leakage.

References Cited UNITED STATES PATENTS Riddle 83380 Seybold et a1. 83390 Barley 83380 Hill et al 833 80 ANDREW R. JUHASZ, Primary Examiner. 5 FRANK T. YOST, Assistant Examiner.

US. Cl. X.R. 83390, 639

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