US3272050A

US3272050A - Adjustable knife and clamp assembly

Info

Publication number: US3272050A
Application number: US474925A
Authority: US
Inventors: Leo D Barley
Original assignee: Harris Intertype Corp
Current assignee: Harris Graphics Corp
Priority date: 1965-07-26
Filing date: 1965-07-26
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13

Description

Sept. 13, 1966 D. BARLEY 3,272,059

ADJUSTABLE KNIFE AND CLAMP ASSEMBLY Original Filed Oct. 2, 1961 5 heets$heet 1 FIG 1 TO RAISE TO LOWER INVENTOR.

LEO D. BARLEY BY MMMM ATTORNEYS Sept. 13, 1966 L. D. BARLEY 3,272,050

ADJUSTABLE KNIFE AND CLAMP ASSEMBLY Original Filed 001;. 2, 1961 5 Sheets-Sheet 2 FIG-H :25 H2123 I38 INVEN TOR.

LEO D. BARLEY @wM/J ATTORNEYS L. D. BARLEY Sept. 13, 1986 ADJUSTABLE KNIFE AND CLAMP ASSEMBLY Original Filed Oct. 2, l96l 5 Shea ts-Sheet 3 w OE QwwOJO I: amxoo niltl zmEo INVENTOR.

LEO D. BARLEY wkm /a ATTORNEYS Sept. 13, 1966 L. D. BARLEY 3,272,050

ADJUSTABLE KNIFE AND CLAMP ASSEMBLY Original Filed Oct. 2, 1961 if) Sheets-Sheet 4 JNVENTOR.

LEO D. BARLEY BY M M 73 ATTORNEYS United States Patent 3 272,050 ADJUSTABLE KNIFli. AND CLAMP ASSEMBLY Leo D. Barley, Dayton, Ohio, assignor to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Continuation of application Ser. No. 142,314, Oct. 2, 1961. This application July 26, 1965, Ser. No. 474,925 9 Claims. (Cl. 83390) This application is a continuation of copending application Serial No. 142,314 filed October 2, 1961, now abandoned, and assigned to the same assignee as this application.

This invention rel-ates to machines for cutting paper and the like and more particularly to novel clamp and knife control assemblies for a hydraulically operated knife and clamp mechanism.

In cutting machines adapted to cut various size stacks or piles of paper or other sheet material, which may be of varying thickness or height, the pile is held in position for the cutting stroke by a clamp prior to the cutting action of the knife. With the pile thus engaged by the clamp, a knife blade mounted in front of the clamp comes down in a guillotine-like cutting stroke to sever the pile at the preselected cutting plane. After the cutting cycle is complete, the clamp and knife move to an upper or raised position, and the machine is ready for the next clamping and cutting cycle.

Many paper cutters and the like are provided with a back gage or spacer which operates as the clamp and knife move to the raised position to advance the pile a predetermined distance for the next cut. Downward movement of the clamp and knife during movement of the back gage is prevented by an interlock circuit which deenergizes the clamp and knife until such time as the back gage has advanced the pile the proper amount. The movement of the clamp and knife to the fully raised position, for example six inches off the cutting table, involves some wasted time in instances where a 1- or 2-inch pile of paper is being cut.

It is desirable in order to increase the rate of cutting to control the distance the clamp and knife are raised above the pile, thus enabling the operation of the back spacer at the time the clamp reaches a preset raised position. In instances where no back gage is provided, or a manually operated back gage is provided, moving the clamp and knife to an upward position short of the fully raised position still serves to increase the rate of cutting by decreasing the time involved in raising the clamp and knife to the fully raised position.

Also, it is desirable to be able to position the knife and clamp a slight distance above the surface of the pile being cut, preferably a preselected distance above a pile regardless of the height of the pile. Further, it is desirable to limit the clearance between the surface of the pile and the knife and clamp members when in the raised position so as to minimize the possibility of the operator injuring himself by placing his fingers between the top of the pile and the base of the clamp. With the clamp and knife control mechanism of the present invention, it is possible to position these relatively heavy units a very small distance above the surface of the pile.

Another advantage of being able to position the clamp and knife assembly while in the raised position at any point above the surface of the pile occurs in operations where soft paper, pressure sensitive carbon paper and the like are being cut. In this situation, movement of the clamp from the fully raised position to the clamping position may cause sufficient pressure to be exerted on the paper to leave a permanent impression thereon,

while the normal pressure of the clamp during the clamping cycle would not produce such an impression. Such a permanent impression would not normally occur during the clamping cycle since the operator may adjust the clamping pressure to such a value as is necessary to hold the pile and yet not have a permanent impression thereon. For example, in cases where a two inch pile of soft paper is being cut, the downward movement of the clamp four inches from an assumed fully raised position may be sufficient to mark the paper permanently due to the downward momentum of the clamp. In accordance with the present invention, the possibility of such permanent damage to the paper is substantially eliminated since the operator may position the clamp and knife at any preselected distance above the surface of the pile when in an inoperative position so as to minimize the effect of the downward momentum of the clamp.

Accordingly, it is an object of this invention to provide a novel hydraulically operated knife and clamp assembly adapted to be positioned a predetermined distance above the surface of the pile, regardless of the height of such pile, when the clamp and knife are in the raised position.

Another object of this invention is to provide novel clamp and knife control assemblies for maintaining the knife and clamp members, while in a raised position, a preset distance above the surface of the pile.

It is another object of this invention to provide a hydraulically operated knife and clamp control assembly which enables operation of a back gage and spacer control as soon as the clamp and knife member are positioned a preset distance above the surface of the work.

table.

A further object of this invention is the provision of a clamp control assembly, including a selectively movable clamp control handle, whereby the clamp member may be moved in response to movement of the handle, and wherein the position of the control handle determines the position of the clamp above the work table.

A further object is to provide a novel clamp and knife control assembly which positions the knife and clamp members a predetermined distance above the surface of the pile when these members are in the raised position, thereby allowing an increase in the number of cutting cycles per unit of time.

It is a further object of this invention to provide a knife assembly which may be positioned a preset distance above the surface of the work table when the knife is in a raised position.

A still further object of this invention is the provision of a novel clamp and knife control assembly for positioning the clamp and knife members a preset distance above the surface of the work table in such a relation that the cutting edge of the knife is maintained above the lower edge of the clamp.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings:

FIG. 1 is a schematic front elevational view of a cutting machine constructed in accordance with the invention and showing the relative positions of the knife, clamp and control assemblies;

IFIG. 2 is a schematic side elevation as viewed from the right of FIG. 1 showing the position of the knife, clamp and control assemblies;

FIG. 3 is an enlarged view of the clamp and knife positioning control handle as seen from the front of FIG. 1;

IFIG. 4 is a view partly in section and partly in elevation taken generally along the line -44 of FIG. 3;

FIG. 5 is a schematic elevational view of the position of the control handle as seen from above FIG. 3;

FIG. 6 is a somewhat diagrammatic perspective view of the control assembly for the clamp and knife members;

FIGS. 7a to 9b are schematic views of the clamp con trol assembly showing the relative positions of the several elements and the clamp positioned different distances above the work table;

FIG. 10 is a fragmentary perspective view of the knife blade, clamp, work table, and indexing marks;

FIG. 11 is a view of a modified form of the position control handles with parts broken away to expose the interior working mechanism thereof;

FIG. 12 is an end view of the position control handles as seen from the right of FIG. 11;

FIG. 16 is a schematic plan View of the position control handles shown in FIG. 11 in another position;

FIG. 14 is a view on an enlarged scale, partly in section and partly in elevation, of the knife control assemy;

FIG. 15 is a sectional view taken along the line 1 5 1-5 of FIG. 14;

FIG. 16 is a view from the left of FIG. 14 of the knife control position indicator;

*FIG. 17 is a schematic diagram of the hydraulic assembly which provides the power for the knife and clamp assembly; and

FIG. 18 is a schematic diagram of the electrical circuit for the cutter, showing the electrical controls for the various components.

In accordance with the present invention, the above objects are accomplished by a novel clamp control assembly which includes a clamp control handle conveniently located on the front side of the cutter and operable to select a position at which the clamp will stop when moving in the raised direction. Movement of the control handle results in a corresponding movement of the clamp, and thus it is possible to raise and lower the clamp to vintually any position between the work table and its fully raised position by merely moving the control handle. Having positioned the clamp at a desired height above the work table, and thus a given height over the surface of the pile being cut, the clamp will, during the termination of each clamping and cutting cycle, move to a raised position a preset distance above the surface of the work table as determined by the relative position of the control handle.

For control of the knife position, a novel knife control assembly is provided which operates independently of the clamp control assembly to the extent that the knife may be positioned in such relation to the clamp that the cutting edge of the knife is above the clamp but below its fully raised position. A novel electrical circuit is provided which will always raise the knife to a position where the lower edge of the knife is above the lower edge of the clamp, thereby preventing exposure of the cutting edge below the edge of the clamp. To this extent, the position of the knife is dependent upon the position of the clamp. In normal operation of the embodiment shown, the clamp and knife control assembly are separately adjust'able to position the clamp and knife members respectively at any position above the work table, and the electrical circuit is in the nature of a safety feature which is operative only in those instance where the relative positions of the knife and clamp are momentarily such that the knife edge is exposed below the clamp.

Referring to the drawings, which illustrate preferred embodiments of the present invention as briefly described above, FIGS. 1 and 2 show a paper cutting machine having a base 10 and side frame members 12. Located approximately midway up the side frame members is a work table 14, above which is arranged a clamp member 15, and a knife blade 17 and blade supporting block 19 positioned to the front of the clamp. Beneath the work table 14, and generally to the right of the machine is a position control handle assembly, generally designated '22, which can be adjusted manually to position the clamp member a preset distance above the surface of the pile of paper being cut, and intermediate its fully raised position and the table surface.

Arranged approximately midway between the side frames on the front of the cutter is a control handle 24 which is operative to advance a back gage '25 manually through a conventional lead screw -(not shown), thereby advancing the pile subsequent to each cutting cycle. The back gage lead screw may also be motor operated, and controlled automatically :by known means such as shown in Spiller Patent No. 2,649,155, issued to the assignee of this application. Provision is made for bringing the clamp member 15 down to the surface of the pile independently of the knife by means of a treadle unit 26 conveniently located on the lower left front side of the cutter. Operation of this treadle allows movement of the clamp member in situations where the operator desires to use the front face of clamp member 15 as a guide to determine the exact point of the cutting plane. Depressing the treadle 26 causes the clamp to move in a downward position corresponding to the amount that the treadle is depressed, and if desired the operator may, by depressing the treadle to the full lower limit of movement, exert full clamping pressure on the pile.

The operating mechanism for moving the clamp from the preset raised position to the clamp position, and back to a preset raised position, includes the hydraulic cylinder (i.e., motor) 30 which is pivotally aflixed at one end 32 thereof to the frame, and has a piston rod 34 connected to a rocker arm 36 for rotation thereof as the piston rod 34 moves out of the cylinder. The rocker arm is splined or otherwise attached to a drive shaft 40 which is rotatably supported in the side frames 12 by suitable bearings 42. Driving connection between the clamp member 15 and the driving rod 49 is made by driving linkages 44 located proximate the terminal ends of the driving rod for urging the clamp in an upward or downward position as the rocker arm is rotated as a result of the movement of piston rod 34.

The movement of the knife blade 17 and knife supporting block 19 is accomplished by means of a hydraulically operated knife assembly including hydraulic cylinder 45 having one end thereof afiixed to the frame, as at 48. The piston rod is pivotally attached at 52 to a bellcrank linkage 54, the latter being mounted by pivot shaft 56 in side housing 57 for urging a connecting rod 58 in a generally downward direction about pivot 60 as the piston 50 is forced out of the cylinder.

The connecting rod 58, which is pivotally attached at 62 to the extending portion 64 of the knife supporting block 19, urges the knife blade 17, which is afiixed to the supporting block 19, in a generally downward guillotinelike cutting stroke. This type cutting stroke is assured by having the extending portions 64 provided with guide- Ways 66 which travel over guides 68 pivotally affixed in the frame of the machine.

Located on one side and generally to the rear of the machine is a motor 70 having its drive shaft 71 connected by means of V-belts 72 to the drive shaft 73 carrying a flywheel 74. The drive shaft is connected to hydraulic pumps, not shown in FIG. 1. In operation, subsequent to the proper alignment of the paper, the operator energizes the appropriate controls for a clamping and cutting cycle, involving the simultaneous action of both the clamp cylinder 30 and the knife cylinder 45. However, for ease of description these operations will be described sequentially. As piston rod 34 moves out of cylinder 30, the rocker arm 36 is rotated thereby causing rotation of the driving rod 40 which urges the clamp 15 in a downward direction due to driving linkage 44. As the clamp reaches the clamping position, the knife piston 50 is extended causing pivotal movement of bellcrank 54, thereby urging connecting rod 58 in a generally downward direction to move the knife supporting block 19 and knife in a guillotine-like cutting stroke since the rotatable guides 68 cause the knife and supporting block to move in a generally downward lateral direction.

After the knife has cut through the paper, piston rod 50 is drawn into cylinder 45, again pivoting bellcrank linkage 54 to urge the connecting rod 58 in a generally up ward direction to position the knife at a preset raised position selected in accordance with the adjustment of a position control assembly as will be subsequently discussed. As the knife blade is being raised, the clamp assembly starts to move to the raised position, since piston rod 34 is then forced into the cylinder 30, as controlled by the clamp position control assembly 22, thereby rotating rocker arm 36 and driving rod 40 to bring the clamp to a predetermined raised position by intermediate driving linkages 44.

Clamp conitrol assembly FIGS. 3 to 5, wherein like reference numerals have been employed for the same elements, show the details of the clamp position control assembly which includes handle 75 connected to the underside of the work table 14 by means of a bracket 76 and a bolt and nut assembly 78 which also holds a friction brake generally designated 79. Aflixed approximately midway between the terminal end of the control handle and the bolt, which forms pivot point 80, is a pulley 81 which is freely rotatable on arm 75 and afiixed thereto by a bolt or other suitable means 82. The interior of the friction brake 79 (shown in FIG. 4) consists of a pair of friction members 83 in the form of washers, one being interposed between the handle or arm 75 and the underside of the bracket 76, the other being positioned between arm 75 and retaining ring 84, the latter member being urged towards the bracket 76 by a cup-shaped spring or Belleville washer 85 held against the retaining ring by -a nut and lock nut assembly 86. The braking or holding friction of this unit can be adjusted by tightening up the lock nut assembly 86 thereby forcing the cup-shaped spring 85 against the retaining member 84.

Aflixed to the underside of the bracket 76 are

stop pins

87 and 88 for limiting the rotational movement of the control arm 75 by engaging the extending portion 89 positioned on the side opposite the pulley 81. Since the control arm 75 will be held by the friction brake in any intermediate position, it is possible to adjust this arm in various positions there-by controlling the raised position of the clamp and knife members, as will be described hereinbelow.

The details of the clamp position control assembly are shown in FIG. 6 wherein continuity of reference numerals has been maintained and wherein the parts are shown in the relative positions they would occupy if the clamp were in the fully raised position. Connected to rocker arm 36, proximate the driving rod 40 and between piston rod connection 34 and the driving linkage 44, is a Y-shaped adapter 90 having attached thereto a flexible cable 92. This cable, of fixed length, is threaded over a first freely rotatable pulley 94, secured to the underside of the frame and generally to the rear thereof upon a bracket 97, and then around pulley 81 of handle 75, .back through a further idler pulley 98, and down to a rotary valve 100, with the terminal end of the cable attached to an arm 102 of the rotary valve. The valve 100 controls pressure conditions in the cylinder 30, as shown in FIG. 17, and as more fully described below. This valve is urged toward a normally closed position by a tension spring 103 afiixed at one end to the arm 102 and at the other end to the frame of the machine.

Operation The operation of the clamp control assembly and the rotary valve 100 may be understood with reference to FIGS. 7 through 10. As seen in FIG. 10, the clamp 15 and the knife 17 are positioned above the work table 14, the clamp being approximately four inches above the work table as indicated by the scribe mark 104 along the side of the cutter. In order to illustrate the several positions and the mode of operation of the clamp as controlled by the clamp control assembly, it will be assumed that the clamp 15 is raised the full or maximum six inches above the work table 14 as shown in FIG. 7b. With the clamp in this position relative to the work table, the elements of the clamp control assembly will occupy the relative positions shown in FIG. 7a, that is, the clamp control handle 75 will be positioned such that the clamp will be in its fully raised position, and the driving linkage 44 and Y- shaped adapter will be at the extreme end of their clockwise movement.

The rotary valve 100, which is of conventional design, is assumed for this explanation to have three positions, open, partially or fracti-onally open, and closed, as indicated in FIG. 7a. In the open position, the valve permits hydraulic liquid holding the clamp in the raised position to be returned to the reservoir, as will be hereafter described, so that there is not enough pressure in the clamp cylinder to hold the clamp in the raised position. With the valve in the partially open position, a pressure equilibrium is established whereby the hydraulic pressure is sufiicient to hold the clamp in the raised position but is insufficient to cause any upward movement of the clamp. With the valve in the closed position, sufiicient hydraulic pressure may be applied to the clamp cylinder and the clamp will be moved in an upward direction.

As shown in FIG. 7a, the arm 102 of the valve is positioned such that the valve is partially open to maintain only a sufficient amount of hydraulic pressure to hold the clamp stationary in the raised position, i.e., counterbalancing the clamp assembly.

During a clamping and cutting cycle, driving rod 40 is rotated in a counterclockwise direction to move the Y- adapter 90 and the driving linkage in a counterclockwise direction. This movement of the driving rod allows the cable 92 to pass around pulley 81, while spring 103 maintains sufficient tension on the cable to urge the arm 102 to the closed position as indicated at 102a. If a threeinch pile of paper 109 were on the work table 14 (see FIG. 7b) the clamp 15 would be positioned in engagement with the surface of the pile and arm 102 would be rotated downward to position 102a as viewed in the draw ings.

On the other hand, if there were no paper on the table 14 and a clamping and cutting cycle was initiated, clamp 15 would move to the surface of the table 14 and arm 102 would be rotated downwardly so that it would be positioned generally along line 106 which represents approximately the terminal limit of movement of Mm 102 in the closed direction. It is understood that some play is provided in the closed direction as indicated by the clearance between stop pins 107 and legs 108 as shown in FIG. 6, however, in normal operation and if properly adjusted, the arms will not be rotated against the stop pins.

Assume that the operator now desires to position the clamp, in the raised position, a short distance above the pile 109 as shown in FIG. 8b. As the control arm 75 is rotated clockwise about pivot 82, the arm 102 of valve is rotated to open position 1021: as shown in FIG. 7a. With the valve 100 opened, the pressure holding the clamp in the up position decreases, and the clamp begins to move downward due to its own weight causing driving rod 40 to rotate counterclockwise. The counterclockwise movement of Y-adapter 90 feeds cable 92 over the pulley dicated by the scribe marks 104 on the side of the cutter frame, and a preset distance above the pile 109 (FIG. 8b) The elements of the clamp control assembly are now in the relative positions as indicated in FIG. 8a. It should be noted that the arm 102 of valve 100 is in the same position with the clamp raised to its full height at it would be if the clamp were raised, for example, three inches above the work table as can be seen by a comparison between FIGS. 7b and 8b. While the arm 102 is in the same relative position as shown in FIGS. 7a and 8a, it should be further noted that the clamp in FIG. 8b is at a lower raised position than in FIG. 7b.

The cable 92 is of fixed length, and accordingly, it can be seen that adjustment of the relative position of the clamp above the work table is accomplished by varying the distance between the pulley 81 and the valve 100, the difierence in such distance being taken up by rotation of the driving shaft 40 to vary the clamp position in accordance with the movement of the clamp control handle 75. Thus, the valve 100 is in the partially open position with the clamp halted at some point intermediate the fully raised position and the work table, and the position'of arm 102 is the same regardless of the position of the clamp, as long as the clamp is at some raised position and stationary at that position.

During a clamping cycle, it the clamp is in a raised position a small distance above a three inch pile, for example, as shown in FIG. 8b, the initial downward movement of the clamp will cause arm 102 to move, as shown in FIG. 8a, to the closed position 1020. Since the valve 100 is closed, at the end of the clamping action, the hydraulic system (to be described below) will raise the clamp, thereby rotating the arm of the valve to the partially open position, and the movement of the clamp will cease as the clamp reaches the raised position as determined by the position of control arm 75.

If it is desired to lower the position of the clamp to a raised position closer to the work table, and a small distance above a relatively small pile, as indicated in FIG. 9b, the control arm 75 is moved from the position shown in FIG. 8a to the position shown in FIG. 9a which causes the arm 102 of the valve to move to the open position 102d as indicated in FIG. 8a. The sequence of movements which now takes place is the same as was discussed above in connection with adjustment of the clamp from the fully raised position (FIG. 7b) to a position intermediate the work table and fully raised position (FIG. 8b).

If it is desired to raise the clamp to the fully raised position (FIG. 7b) from a relatively low position (FIG. 9b), the operator moves the control arm 75 from the position shown in FIG. 9a to that shown in FIG. 7a. As the control arm 75 is so moved, the spring 103 urges the arm 102 into the closed position 102e (FIG. 9a) and the developed hydraulic pressure will raise the clamp by causing clockwise rotation of driving rod 40. As the driving rod 40 rotates, cable 92 is pulled over pulley 81 and arm 102 is moved an amount proportionate to the rotation of rod 40. until the clamp is in the fully raised position and at that time arm 102 will be in the partially open position as show-n in FIG. 7a.

From the above description of the clamp control assembly, it can be seen that movement of the control handle 75 results in an almost immediate responsive movement of the clamp 15, by an amount proportionate to the displacement of the arm 75. It is possible to move the clamp from its fully raised position down to the surface of the work table and back to its fully raised position by manipulating the control handle from a position representing full clamp height to low clamp height and back to full clamp height. It is of course understood that such movement of the clamp by the control handle 75 does not produce any clamping pressure but merely allows the clamp to come down since the rotary valve is positioned so as to reduce the hydraulic pressure, and as the clamp and 124 on each side of the hub 125.

reaches the work table, movement of the control handle to the fully raised position operates to close the rotary valve, causing an increase in pressure to raise the clamp. As the clamp reaches the fully raised position, the arm of the rotary valve is rotated to its partially open position as above described and the clamp comes to a halt.

If it is desired to apply clamping pressure without going through a clamping and cutting cycle, a conventional treadle assembly as above described may be employed.

FIGS. 11 through 13 show a modified form of a position control handle which allows selection of a desired preset raised position, variation from that preset raised position, and return to that position by simple manipulation of the control handle. Means are provided between a slightly modified form of the control handle 111 and a bracket 112 for selecting a preset adjustment which is most frequently used and for holding the control handle in that position. Such means include a position selection handle 115 pivotally mounted on the bracket 112 by means of a bolt 116 and a cup-shaped spring assembly 118. The position selection handle is maintained in sliding frictional relationship to the control handle by friction washers 122 Interposed between the friction washer 124 and the hub 127 of control handle 111 is a spacer 129 which allows movement of the control handle 111 independent of the position selection handle 115. The spring assembly 118 serves to control the frictional resistance to movement of the handles, and the triction thereof may be increased or decreased by suitable adjustment of a lock nut assembly 132.

A handle engagement mechanism is located on the ends of the position control and position selection handles for causing interlocking of the handles as one is moved across the path of the other, and consists of an aperture 138 formed in the underside and end of the position selection handle 115 for receiving a pin 140 which is urged by spring 142 out of the upper face of the end of position control handle 111. A pin handle 145, traveling in slot 147 and retained therein by plate 149, is mounted through the pin 140 for manually depressing the latter for engaging or disengaging the handles as the handles are moved together or as one handle is moved relative to the other, respectively.

Each handle is capable of being moved independently of the other and both are limited in their arcuate movement by stops 150 (one of which is shown) contacting extending

portions

154 and 156 of the handle 115 and 111, respectively. The operator adjusts the position selection handle in the desired location in accordance with the desired raised position of the clamp. If the two handles are interlocked by the handle engagement mechanism 135, then movement of either handle causes movement of pulley 81 and alters the raised position of the clamp. With the position selection handle 115 arranged for the setting most frequently used, for example a setting representing a raised position four inches above the work table, the operator may disengage the handles by depressing pin handles 145, and move handle 111 independently of handle 115 to alter the position of the clamp While retaining an indication of the setting most frequently employed. Such a relationship is shown in FIG. 13 wherein the position selection handle 115 may be positioned at the fourinch mark while the position control handle 111 is arranged at the two-inch mark, for example.

As the cutting operation of the larger height pile, for example four inch, is finished and a smaller pile is being cut, for example a three inch pile, the operator depresses the pin handle 145 and moves the position control hand-1e 111 toward the position selection handle 115. As the two handles come into alignment, the end of handle 111 touches the guide plate 160 affixed to the position selection handle 115 (FIG. 12) to align the pin 140 with the aperture 138. Release of the pin handle 145 allows the pin 140 to engage the aperture 138 and the handles 111 and 115 are in turn locked and may be moved together to any desired position.

The provision of a preset handle such as 115 facilitates positioning the clamp in a raised position, especially in instances where the majority of the cutting work involves piles of a given height, as for example cutting and trimming piles of magazines which come off a printing press in piles of fixed height, or from paper making machines where piles of sheets of given height are run off.

Knife control assembly Means are provided as shown in FIGS. 14 to 16 for controlling the upward movement of the knife, and include a knife control switch 180 which may be po-sitioned with respect to a cam plate 182 such that switch 180 is tripped as the knife reaches the desired raised position thus activating the knife power unit (to be described below) which halts the movement of piston 50 into cylinder 45. The knife control switch 180 is afiixed to a mounting bracket 184 which is supported on the mounting collar 186, the latter fitting over the reduced end portion 188 of pivot shaft 56. The cam plate 182 is secured to the upper lug 190 of the bellcrank 54 by a bolt 192 for movement therewith as the bellcrank moves to permit engagement between the button 194 of switch 180 at such time as the bellcrank rotates to raise the knife. The point at which contact is made between button 194 and the cam plate 182 depends on the relative position of the switch about the outer periphery of shaft 56.

Means are provided for adjusting the position of the switch including a circular friction plate 196 having an aperture 198 therein and secured by bolt 197 to the face end portion 188. Movement of the mounting collar 186 is accomplished by rotation of a control knob 200 which is secured to a collar 202 by bolts 204, the latter being connected to the mounting collar 186 by .a pin 206 to provide a control knob assembly movable as a unit to position the electrical switch 180. Frictional resistance to movement of the control knob assembly is provided as a result of the high friction between the overlapping seat portions 208 of the friction plate 196 and the collar 202. Since a spring 210 is held in an aperture 212 of the end portion 188 and abuts the spring plate 213 in the center of the control knob 200, the spring tends to urge the collar 202 away from the shaft 56, thereby forcing the collar into engagement with the friction plate 196 to insure contact between these two members at the overlapping portions 208 thereof. The amount of friction may be varied by adjusting bolt 214 which moves spring plate 213 relative to the end portion 188 of shaft 56 to vary the force exerted by the spring 210.

Mounted on a lower lug 220 of the bellcrank 54 is a contact arm 222 for operating a knife down switch 225 (FIG. 14) which is affixed to the frame and positioned to be engaged by contact arm 222 as the knife reaches the cutting stick at its lowermost position of a cutting stroke.

Operation of knife control assembly In operation, the operator rotates the control knob 200 until a scribe mark 226 is aligned with the desired setting on the template 227 (FIG. 16) fixed to the guard housing 229. The graduations on the template indicate the distance above the work table and rotation of the knob 200 results in rotation of the knife control switch 180. As the knife begins to move downward as a result of the rotation of the bellcrank 54 about pivot shaft 56, the cam plate 182 moves in arcuate upward movement with respect to the pivot shaft 56 as shown in the dotted 'line portion of FIGS. 14 and 15. Approximately at the saem time the knife strikes the cutting stick, the contact arm 222 of the lower lug 220 contacts the knife down switch 225, as shown in the dotted line portion of FIG. 14. The bellcrank 54 now rotates in a reverse direction about shaft 56 to raise the knife and as the cam plate 182 contacts the button 194 of the knife control switch 180, the knife stops its upward travel and is positioned in accordance with the setting of the knife control knob 200.

Positioning movement of the control switch 180 in an arcuate upward direction, as shown in the dotted lines of FIG. 12, serves to shorten the interval required for the cam plate to contact the switch as the knife is being raised, thereby stopping the knife at a position closer to the work table.

Hydraulic system The schematic diagram of a hydraulic system for developing the power necessary for operation of the knife and clamp assembly is shown in FIG. 17, and consists basically of two units, the first controlling the clamp, and the second con-trolling the knife. A double pump assembly 250, consisting of a larger pump 252 of about 11 gallons per minute capacity and a smaller pump 254 having a capacity of approximately 3 gallons per minute, is driven from shaft 73 (FIG. 1) and supplies fluid under pressure constantly to the

hydraulic cylinders

45 and 30 of the knife assembly and clamp assembly, respectively. Hydraulic fluid is drawn through the filter 256 and flows from pump 254 through filter 258 to pilot conduit 260, and from there through check valve 262 to conduit 264. The supply of pressurized fluid is controlled by a clamp directional valve 265 operated either by a solenoid 266, or a mechanical control mechanism 268, to position the valve, which in the normal rest position is spring-biased to allow flow to conduit 270. An up-relief valve 272 is connected to conduit 270 for controlling the pressure in the system as the clamp valve 265 is in the rest position to allow fluid flow through

conduits

270, 274 and 276 to the clamp cylinder 30 for raising the latter in accordance with the adjustment of the position control assembly, shown in schematic form. Conduit 276 is connected at the other end to the rotary valve which allows passage of fluid to return line or tank T as the valve moves to the open position.

As solenoid 266 is energized to bring the clamp down, the valve 265 changes position and conduit 264 is connected to conduit 278 thereby allowing pressurized fluid to flow to the bottom of the clamp cylinder 30, and

conduits

276, 274 and 270 are connected to the return line or tank T. A clamp pressure adjusting valve 280 is located between the check valve 282 and the clamp valve 265, and allows adjustment of the clamping pressure as various types of paper or material are being cut. The clamping pressure can be read off the pressure gage 284 which is tapped into conduit 278.

The components of the hydraulic control for operation of the knife assembly include the knife pilot direction valve assembly 285, which is a low capacity valve used to position the main knife control valve 290 so as to allow a large volume of fluid to reach the knife cylinder. Fluid from the small capacity pump 254 flows through pilot conduit 260, through choke 292, to the knife pilot valve 285 which is a three-position valve spring biased to the neutral position. The output of the large capacity pump 252 is connected to the knife valve 290 by conduit 294, the pressure of this system being controlled by proper adjustment of the knife relief valve 296 similar in function to valve 280. In accordance with the movement of valve 285, as controlled by the up or down

electrical solenoids

298 and 300, respectively, fluid is ported either through

conduit

302 or 304 to shift the knife valve 290 to the up or down position, this valve being normally spring biased to the neutral position. Depending on the direction of movement of the knife valve 290, pressure fluid is directed either to conduit 306 to lower the knife by movement of the piston 50 out of the cylinder 45, or fluid is ported to conduit 308 to force the piston 50 back into the cylinder 45 to raise the knife. A counter-balance valve 310 serves to insure pressure 11 in the hydraulic knife cylinder 45 at all times so that the knife blade comes down in a smooth guillotine cutting stroke. To prevent fluid from passing into conduit 274 from line 308, a check valve 312 is placed in the line and operates to close when a one pound pressure differential exists.

Hydraulic system operation In operation, assuming that the clamp and knife are in the same preset raised position, the clamp valve is positioned to allow passage of fluid to the clamp cylinder 30 for holding the clamp in the raised positions, since fluid is looked between check valve 262 and the rotary valve 100, which closes as the clamp begins to move in a downward direction. The rotary valve 100 is opened partially or slightly with the clamp in the raised position, however sufllcient pressure is maintained in the system to hold the clamp in the preset raised position without the assistance of any mechanical holding means. The knife is held in the raised position since fluid is locked between check valve 312, the knife cylinder 45 and the knife valve 290, the latter being in the neutral position. Any passage of fluid from

conduits

274 and 308 and out to tank pressure is prevented by the fact that the knife valve 290 is in a natural position thereby sealing conduit 308 from the return system T.

Subsequent to the adjustment of the position control handle 75 and the knife control knob 200 for selecting the upper most position of the clamp and knife above the work table, the operator energizes the cutter for a clamping and cutting cycle. Solenoid 266 is energized V to position valve 265 such that conduit 264 is connected to 278, and conduit 270 is connected to the return system. With conduit 270 connected to the return line, the piston 34 moves out of the cylinder, the clamp begins to come down, and inasmuch as the pressure fluid flow may be slower than movement of the piston 34, fluid can be drawn through check valve 282 from the return system. As the clamp reaches the surface of the pile, the pressure fluid is applied to the cylinder, the latter being substantially full of fluid drawn through the check valve 282 at tank pressure, and full clamp pressure is applied according to the setting on the clamp pressure adjusting valve 280.

The initial movement of the clamp piston 34 allows the cable 92 to play out and rotary valve 100 is closed. Fluid on the reverse side of the piston flows out conduit 276 through 274 and 270 and through the valve 265 to the return line or tank T.

Through an appropriate electrical circuit, the down solenoid 300 of the knife solenoid valve 285 is energized to shift the valve and connect pilot conduit 260 to conduit 304, and accordingly shift the valve 290 to the down position. With valve 290 in the down position, supply conduit 294 is connected to 306 and conduit 308 is connected to the return line T through valve 290, however, the knife does not move down at this point due to the action of the counterbalance valve 310. Fluid cannot flow through the check valve 314 to conduit 308, and does not pass through valve 310 until sufficient pressure is developed to allow a continuous, smooth cutting stroke of the knife. After the pressure builds up, valve 310 opens allowing fluid to flow from the forward end of the knife cylinder 45 at the same rate that fluid under pressure enters the cylinder thereby insuring a continuous smooth cutting stroke.

As the knife blade reaches the conventional cutting stick, electrical switch 225 (FIG. 14} is energized by contact arm 222 resulting in the energization of the up solenoid 298 of the knife solenoid valve 285, while the down solenoid 300 is deenergized by an appropriate electrical circuit to be described below. By this action, conduit 260 is connected to conduit 302, and conduit 304 on the down side of the knife valve is connected to the return line or tank T. Subsequent to the cutting action of the knife, and approximately at the same time the knife blade is moving upward through the pile, the solenoid 266 of the clamp valve 265 is denergized by an appropriate electrical circuit, and this valve is spring biased to connect conduit 264 to conduit 270, while conduit 278 is connected to the tank or return line T. As the piston 34 is forced down into the cylinder, the cable begins to move, opening the rotary valve as the clamp reaches the proper height in accordance with the position of the control handle 75.

The shifting of the valve 290 for up operation of the knife connects supply conduit 294 to conduit 308, while 306 is connected to the tank or return line T. At this point, both the knife and the clamp are moving in an upward direction away from the work table, and as the rotary valve 100 partly opens and the clamp stops its upward movement, the knife will stop its upward movement due to deenergization of the up solenoid 298 of valve 285 by appropriate electrical circuits to be described hereafter in connection with FIG. 18. Check valve 312 prevents flow of fluid from conduit 308 to conduit 274 thereby maintaining pressure for the upward movement of the knife. Deenergization of the up solenoid 298 allows the spring biased valve 285 to center itself, connecting

conduits

302 and 304 to the tank or return line. Bleeding .of the pressure from each side of the valve 290 allows it to center itself locking the fluid between valve 290, conduit 308, knife cylinder 45, conduit 306 and back to valve 290, while conduit 294 is connected to the return line or tank T.

Movement of the position control handle 75 has the elfect of permitting opening the rotary valve 100 at any one of various points during the upward travel of the clamp, thereby stopping the clamp in a raised position which is preselected in accordance with the position of the control handle 75, intermediate the fully raised position and the surface of the work table.

The movement of the clamp by the treadle 26 (FIGS. 1 and 2) while maintaining the knife in the up position is accomplished by a mechanical connection to the clamp valve 265 as shown schematically at 268. Movement of the treadle operates to move the valve 265 against the spring and release the pressure in the cylinder 30 by connecting

conduits

270, 278 and 274 to the tank or return line T thereby allowing the clamp to move slowly of its own weight. Such movement of the clamp does not allow movement of the knife since pressure is maintained in the knife circuit by check valve 312. Should the treadle 26 be depressed all the way, conduit 264 will be connected to 278 and full clamping pressure is applied as described above. Release of the spring loaded treadle allows the spring biased valve 265 to return to the normal position with conduit 264 connected to 270, and the clamp moves to the raised position according to the adjustment of the position control handle 75.

Electrical circuit The circuit of FIG. 18 for controlling the hydraulic units providing power for operation of the knife and clamp, includes a number of parallel circuits connected between power lines L1 and L2. For description of the circuits it is assumed that the clamp and knife are in a raised position, with relay 350 deenergized as a result of knife control switch being opened due to engagement of the switch with the cam plate 182. With relay 350 deenergized, contacts 350a, 35012 and 3500 are opened while contact 350d is closed. Relay 352 is energized through the circuit completed from L1 through the back contacts of switches 354 and 356- to line 358. Closing of relay 352 closes contacts 352a, 3521; and 3520, which locks circuit 360 into operation until such time as contacts 350d are opened.

The clamp may be lowered without lowering the knife by closing switch 354 to the forward contacts thereby connecting line 362 from L1 through the forward con facts of 354, through the closed contacts 352a to L2 to energize relay 364. Closing of this relay closes contacts 364a and 364b, the latter placing the clamp valve solenoid 266 in a completed circuit between L1 and L2, and energizing the clamp valve to start the downward movement of the clamp, If the switch 354 is returned to the back contacts, the clamp solenoid 266 will remain energized since contacts 364a are closed locking circuit 366 into operation. To raise the clamp, the operator depresses the manually operated clamp release switch 368 to open the line to relay 364 and deenergize the clamp valve solenoid 266, thereby allowing the clamp to move to its raised position. As was mentioned previously, it is also possible to move the clamp by operation of the treadle, and in this case it is not necessary to operate

switches

354 or 368 since movement of the clamp is accomplished by mechanical movement of the clamp valve.

To bring both the clamp and knife down for a clamping and cutting stroke, the operator simultaneously depresses

switches

354 and 356 by manipulation of the appropriate safety handles, as are well known in the art, to energize relay 364 and the clamp solenoid 266, as discussed above, and to energize relay 370 which closes contacts 370a and opens contacts 37Gb to by-pass normally closed switch 374. This sequence prevents energization of the up-solenoid 298 of the knife valve as the clamp moves away from the knife, thereby allowing switch 374 to close. The switch 374 is activated by an arm 374a physically mounted on the clam and operative to open the switch as the knife moves into engagement with the arm 374a] For further information concerning the operation of this switch, reference is made to the United States Patent 2,649,153 issued August 18, 1953 to L. D. Barley, the inventor in the present case, and assigned to the same assignee as this application.

With the knife momentarily in the up position, and the clamp moving downward, switch 374 is opened and switch 225 makes contact on point 376 thereby energizing the down-solenoid 300 through closed contacts 352b and normally closed

knife switches

380 and 382. The

switches

380 and 382 are used to disable the

knife solenoids

398 and 300 at such time as the knife blade is being replaced or repaired, and for further information regarding the function and physical location, reference is made to the United States Patent to Russell 1. Haywood 2,939,357, issued June 7, 1960, and assigned to the same assignee as the resent application.

Operation of the up-solenoid 298 during the downward movement of the knife is prevented since relay 350 can only be energized through line 384 which is connected to contacts 376a of switch 225. As the knife reaches the cutting stick, switch 225 opens to contact 376 and closes to contact 376a, thereby energizing relay 350 to close contacts 350a, b and 0. Since switch 180 is normally closed, this circuit is locked into operation until such time as switch 180 is opened by engagement with the cam plate 182 as the knife reaches the proper raised position.

Energization of relay 350 causes normally closed contacts 350d to open, deenergizing relay 352 and opening contacts 352a, 352b and 3520; opening of the contacts 352a serving to deenergize relay 364 to open contacts 364a. However, the clamp solenoid 266 does not open at this time since the circuit is completed through line 386 and closed contacts 3506'. As the knife reaches the preset raised position, switch 180 opens, deenergizing relay 350 and opening contacts 350a, b and c to deenergize the clamp solenoid 266 thereby allowing the clamp to move upward until the rotary valve 100 of the hydraulic system opens.

Operation of the down-solenoid during the upward movement of the knife is prevented due to the fact that as relay 350 was energized normally closed contacts 350d opened to deenergize relay 352 resulting in the opening of contacts 352d, thereby opening the circuit to switch 225 which is now connected to contact 376.

The above sequence occurs even if

switches

354 and 356 are positioned such that contact is made with the forward contacts thereof due to the fact that deenergization of the relay 352 by the opening of contacts 350d prevents the latter relay from energizing until the

switches

354 and 356 are returned to the back contacts. Such a feature prevents repeated clamping and cutting cycles should the operator fail to release the safety

handles controlling switches

354 and 356 as the clamping and cutting strokes are completed. As the

switches

354 and 356 return to the back contacts, relay 370 is deenergized opening contacts 370a and closing 370b, while relay 352 is again energized in preparation for another clamping and cutting cycle.

If desired, the operator may employ only one hand for the clamping and cutting operation by closing switch 390, then momentarily energizing both

switches

354 and 356, and thereafter releasing the handle for switch 354. In such an instance, an additional feature is present in the circuit in the form of a photocell controlled relay shown by contacts 394, which are normally closed, but open to halt the clamp and/ or knife if the operator should place his hand into the cutting plane.

Should the switch be positioned to allow movement of the knife to the fully raised position, switch 374 serves to deenergize the up-solenoid 298 as the clamp and knife reach the fully raised position. Further, switch 180 functions to allow raising of the knife, if the clamp is raised to the fully raised position, by energizing the up solenoid 300 due to switch 374 which closes as the clamp is moved higher than the knife. Means are also provided for halting the knife in the down position by manually operated stop down switch 398 which effectively takes the up-solenoid 298 out of operation as long as the switch remains opened. If it is desired to raise the knife from the down position in small controlled increments, switch 400 may be used.

In normal operation of the cutter, the operator adjusts the clamp handle and the knife position handle such that in their raised position, the knife will be slightly above the clamp (see FIG. 10) so that the cutting edge does not project downward beyond the face or edge of the clamp thereby exposing the sharp cutting edge and leading to possible injury. The circuit of the present invention has been designed to prevent such an occurrence by employing two parallel circuits for controlling the up position of the knife in accordance with the preset up position thereof. The first of these parallel circuits interconnects L1 and L2 through the contacts 37%, switch 374, stop down switch 398 and the solenoid 298. The second circuit interconnects L1 and L2 through contacts 350a, knife control switch 180, contacts 350b, stop down switch 398 and the up-solenoid 298.

Assume that a out has been made and

switches

354 and 356 are returned to the back contacts deenergizing relay 370 and allowing contacts 37% to close, then as the knife moves to the preset raised position, switch 180 is opened.

If the switch 374 opens at approximately the same time as does switch 180, the knife will come to a halt; however, if the switch 180 opens and the knife edge is below the clamp, the circuit through the switch 374 and contacts 37011 serves to maintain the up-solenoid 298 energized until the knife edge is above the surface of the clamp. This situation will occur whenever the operator has positioned the clamp above the surface of the knife edge, and the parallel circuit arrangement acts to prevent exposing the knife edge thereby preventing possible injury to the operator.

In accordance with the present invention, and due to the fact that it is possible to maintain the knife and clamp member at the same preset distance above the surface of the pile of material but intermediate the fully raised position, the performance of the cutting machine has been considerably improved. For example, if a pile of material five and one-half inches in height is being cut, it is possible to cut at the rate of twenty-two strokes per minute. This is also the cutting rate for piles of smaller height if the clamp and knife are moved from the fully raised position to the operative clamping and cutting position.

Illustrative of the increase in speed possible with the use of the present invention is the fact that, if the knife and clamp are positioned above the surface of the pile a small distance, it is possible to achieve twenty-eight strokes per minute with a four-inch pile, thirty-six strokes per minute with a two-inch pile and fifty strokes per minute with a one-half inch pile.

In addition to the increase in the rate of cutting, the positioning of the knife and clamp a short distance above the surface of the pile eliminates the possibility that any injury could result from having a hand or finger caught between the edge of the clamp and the surface of the pile, due to the fact that it is possible to so position the clamp and knife such that it is impossible to place a finger or hand in the small space.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A clamp control for use with a cutting machine adapted to cut piles of material, said machine including a knife movable in guillotine-like cutting strokes together with a clamp movable from a raised position to a clamping position against a pile of material and a hydraulic unit providing a power drive for said clamp and knife; said control comprising driving linkage means operatively associated with said hydraulic unit for moving said clamp toward and away from a pile, valve means operative to halt the upward movement of said clamp means and to maintain said clamp in the raised position, means controlling said valve means including a cable of fixed length secured at one end to said driving linkage means and at the other end to said valve means for relating the position of said clamp and for causing said valve to halt the upward movement of said clamp by establishing a condition of hydraulic pressure equilibrium, and adjustable guide means controlling the path along which said cable moves to vary the efiective action of said cable on said valve means.

2. A cutting machine adapted to cut piles of material of various heights comprising a work table adapted to receive a pile of material to be cut, power operated knife means movable relative to said work table from a raised position to out said pile of material, power operated clamp means movable from a raised position to a clamping position engaging the surface of said pile of material for holding the same during a cutting stroke of said knife means, first means for controlling the upward movement of said clamp means to halt said clamping means at a position intermediate the raised position and the clamping position in accordance with a preselected adjustment of said first means, second means controlling the upward movement of said knife means to halt said knife means at a position intermediate the raised and cutting positions thereof in accordance with a preselected adjustment of said second means, and third means operative in the event that the cutting edge of said knife means is below the lower edge of said clamp means as said knife and clamp are in an intermediate raised position for raising and maintaining the edge of said knife means above the lower edge of said clamp means.

3. In a cutting machine including a work table for receiving piles of material of various heights to be cut, power-operated knife means normally held in a fully raised position and movable from such position toward said cutting table and back to such positions for severing a pile of material on the table, and power-operated clamp means normally in a fully raised position and movable to a clamping position engaging the top of a pile to hold the pile on the table during a cutting cycle of said knife; the improvement comprising drive means connected to said knife means and capable of operating through a full stroke or a portion of said stroke to cause a cutting cycle of said knife means, drive means connected to said clamp means and capable of moving said clamp means against a pile on the table and back to its fully raised position during a selected cutting cycle, an adjustable control for said clamp drive means operable thereon to terminate the cycle of movement of said clamp means short of its fully raised position during another selected cycle of operation of said clamp means and thereby to halt said clamp means be tween the table and its fully raised position at the end of such other cycle at a partially raised position predetermined to be above the top of a pile, and control means for said knife drive means constructed and arranged to terminate the upward movement of said knife means during such other cutting cycle at a partially raised position above said clamp means and below the fully raised position of said knife means and thereby to shorten the cutting cycle of said knife means for each cutting operation in such other cycle.

4. A cutting machine as defined in claim 3 wherein said control means for said knife drive means includes a device actuated by said clamp means and operable to terminate the upward movement of said knife means at a partially raised position predetermined with reference to said clamp means.

5. A cutting machine as defined in claim 3 wherein said drive means for said knife means is a first double acting hydraulic cylinder and linkage connecting said first cylinder to operate said knife means through its cutting stroke, and wherein said drive means for said clamp means is a second double acting cylinder and linkage connected between said second cylinder and said clamp means, a source of hydraulic fluid under pressure, conduits connecting said source to the respective said hydraulic cylinders, and separate valve means in said conduits for controlling movement of said first and second hydraulic cylinders independently of each other, a control valve means operably connected to bleed hydraulic fluid from said second hydraulic cylinder in a manner tending -to prevent raising of said clamp means, a cable extending between said control valve means and said linkage for said clamp means for causing said control valve means to open and bleed pressure fluid from said second hydraulic cylinder at a predetermined position thereof corresponding to a desired partially raised position of said clamp means, and a clamp control assembly operably connected to said cable for adjusting the timing of opening of said control valve means to change the location of the paitially raised position of said clamp means.

6. A cutting machine as defined in claim 5 wherein the drive means for said knife means includes means for adjusting the partially raised position of said knife means in relation to the predetermined partially raised position of said clamp means.

7. A clamp control assembly for use with a cutting machine adapted to cut piles of material and including a knife movable in guillotine-like cutting strokes together with a clamp movable from said raise position to a clamping position and a hydraulic unit providing a power drive for said clamp, said control comprising driving linkage means connected between said hydraulic unit and said clamp for moving said clamp, valve means operative to halt the upward movement of said clamp means and to maintain said clamp means in a raised position, means controlling said valve means including a position sensing connection between said linkage means and said valve means for relating the position of said clamp means and causing said valve to halt the upward movement of said clamp by establishing a condition of hydraulic pressure equilibrium, adjustable means operatively connected to said sensing connection means for changing the effective action thereof on said valve means in response to clamp movement and thereby to vary the effective action of said sensing means to halt said clamp means at different preselected positions intermediate its raised position and its clamping position, and indicator means operatively associated with said adjustable mean sto maintain an indication of a preselected position of said adjustable means whereby said adjustable means can be returned to a previously selected position.

8. In a cutting machine including a Work table for receiving piles of material of various heights to be cut, power-operated knife means normally held in a fully raised position and movable from such position toward said cutting table and back to such position for severing a pile of material on the table, and power-operated clamp means normally in a fully raised position and movable to a clamping position engaging the top of a pile to hold the pile on the table during a cutting cycle of said knife; the improvement comprising drive means connected to said knife means and capable of operating to cause a cutting cycle of said knife means, drive means connected to said clamp means and operable to move said clamp means against a pile on the table and back to its fully raised position during each said cutting cycle, an adjustable control for said clamp drive means operable thereon to terminate the cycle of movement of said clamp means short of its fully raised position during each cycle of operation of said' clamp means and thereby to halt said clamp means between the table and its fully raised position at the end of each cycle at a partially raised position predetermined to be above the top of a pile, control means for said knife drive means constructed and arranged to correlate movement of said knife means and clamp means during each cutting cycle, and a position selector member cooperating with said adjustable control to indicate a preselected position of said adjustable control and to establish a reference for returning said adjustable control to such preselected position.

9. A clamp control assembly for use with a cutting machine adapted to cut piles of material and including a knife movable in guillotine-like cutting strokes together with a clamp movable from a raised position to a clamping position and a hydraulic unit providing a power drive for said clamp, said control comprising driving linkage means connected between said hydraulic unit and said clamp for moving said clamp, valve means operative to halt the upward movement of said clamp means and to maintain said clamp means in a raised position, means controlling said valve me-ans including a position sensing connection between said linkage means and said valve means for relating the position of said clamp means and causing said valve to halt the upward movement of said clamp by establishing a condition of hydraulic pressure equilibrium, a clamp position control member movable by an operator to determine the intermediate raised position of said clamp, and indicator means including a position selector member movable independently of said position control member for indicating a desired position of said selector member and operatively associated with said adjustable means to maintain an indication of a preselected position of said adjustable means whereby said adjustable means can be returned to a previously selected position.

References Iited by the Examiner UNITED STATES PATENTS 1,710,084 4/1929 Berry 83-390 1,880,598 10/1932 Tyler et a1 83-381 2,649,153 8/1953 Barley 83-381 3,046,874 7/1962 Dehn 83-525 3,052,145 9/1962 Mu'ller et a1. 83-530 3,121,364 2/1964 Castle 83-530 3,160,048 12/1964 Barley 83-390 WILLIAM N. DYER, JR., Primary Examiner.

F. T. YOST, L. B. TAYLOR, Assistant Examiners.

Claims

1. A CLAMP CONTROL FOR USE WITH A CUTTING MACHINE ADAPTED TO CUT PILES OF MATERIAL, SAID MACHINE INCLUDING A KNIFE MOVABLE IN GUILLOTINE-LIKE CUTTING STROKES TOGETHER WITH A CLAMP MOVABLE FROM A RAISED POSITION TO A CLAMPING POSITION AGAINST A PILE OF MATERIAL AND A HYDRAULIC UNIT PROVIDING A POWER DRIVE FOR SAID CLAMP AND KNIFE; SAID CONTROL COMPRISING DRIVING LINKAGE MEANS OPERATIVELY ASSOCIATED WITH SAID HYDRAULIC UNIT FOR MOVING SAID CLAMP TOWARD AND AWAY FROM A PILE, VALVE MEANS OPERATIVE TO HALT THE UPWARD MOVEMENT OF SAID CLAMP MEANS AND TO MAINTAIN SAID CLAMP IN THE RAISED POSITION, MEANS CONTROLLING SAID VALVE MEANS INCLUDING A CABLE OF FIXED LENGTH SECURED AT ONE END OF SAID DRIVING LINKAGE MEANS AND AT THE OTHER END TO SAID VALVE MEANS FOR RELATING THE POSITION OF SAID CLAMP AND FOR CAUSING SAID VALVE TO HALT THE UPWARD MOVEMENT OF SAID CLAMP BY ESTABLISHING A CONDITION OF HYDRAULIC PRESSURE EQUILIBRUIM, AND ADJUSTABLE GUIDE MEANS CONTROLLING THE PATH ALONG WHICH SAID CABLE MOVES TO VARY THE EFFECTIVE ACTION OF SAID CABLE ON SAID VALVE MEANS.