US3389628A - Controls for cutting presses - Google Patents

Description

June 25, 1968 D. E. BANKS ET Al. 3,389,628

CONTROLS FOR CUTTING PRESSES Filed April 15, 1966 13 Sheets-Sheet 1 June 25, 1968 D. E, BANKS ET Al. 3,389,628

CONTROLS FOR CUTTING PRESSES Filed April l5, 1966 15 Sheets-Sheet 2 June 25, 1968 D. E. BANKS ET AL 3,389,628

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June 25, 1968 D. E. BANKS ET AL CONTROLS FOR CUTTING PRESSES Filed April l5, 1966 13 Sheets-Sheet 6 Moor Il u) CBS C'lRcum? RELAY D. E. BANKS ET Al- 3,389,628

CONTROLS FOR CUTTING PRESSES June 25, 1968 l5 Sheets-Sheet '7 Filed April l5, 1966 June 25, 1968 D. E. BANKS ET Al. 3,389,628

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CONTROLS FOR CUTTING PRESSES Filed April l5, 1966 l5 Sheets-Sheet l0 AC DC' DC AC' 43 LEFT RIGHT D/E SEA/.sofa C//acU/r i K8 K 'A KD-B June 25, 1968 D. E. BANKS ET Al.

CONTROLS FOR CUTTING PRESSES 13 Sheets-Sl'xeefI 123 Filed April l5, 1966 June 25, 1968 D. E. BANKS ET AL CONTROLS FOR CUTTING PRESSES eats-Sheet 13 Filed April 15, 196e lllwl |l| .l.| IW M MTN Il H L f R w T l n V1.1 W @mi uw #IIJ IL" w Vllwl QUI United States Patent 3,389,628 CONTROLS FOR CUTTING PRESSES David E. Banks, Hamilton, DonaldF. Herdeg, Beverly, Ralph E. Karcher, Jr., and Abdullah A. Khambaty, Magnolia, and William B. Mercaldi, Beverly, Mass., assignors to United Shoe Machinery Corporation, Boston, Mass., a corporation of New Jersey Filed Apr. 15, 1966, Ser. No. 542,954 13 Claims. (Cl. 83-62) This invention relates to improvements in cutting7 presses and more particularly `to improvements in controls for cutting presses for dieing out parts from sheet material.

The invention is illustrated as embodied in a cutting press of the traveling head type wherein a relatively small platen is supported by yoverhead beam means for movement across a relatively wide work support, but it will be understood that the invention in many of its aspects is not limited to presses of this type.

In dieing out parts from work pieces using die cutting presses, it is a common procedure for the operator to position the work piece on the work support, `and to place, pic-k up, and replace a die on the work piece, using the cutting head after each placement to press the die through the work, until all the intended cuts have been made in that position of the work piece. After every cut, to permit the operator to pick up the cut parts and the die, the platen must be moved transversely to clear the die and for the next cut brought .back over the die in its new position.

-Past efforts .to automate this procedure have provided means for causing the beam or platen of a cutting press to move from a retracted or inoperative position to an operative position over the die, to press the die through the work and then return to the retracted position. This mode of operation incurs a loss of time after the operator has placed the die, which loss is the time required for the operator to move to and operate the lcontrol Iand for the beam or platen to be moved over `the die from its retracted position. In other words, the operator, after placing the die, has to move his hands, work the controls and await a comparatively large amount of time for the platen to move over the die, as well as the .times for the platen to press the die through the work and get out ofthe way, before he can pick up the die and replace it. We have found that substantial operating time may [be saved by la mode of operation in which the beam or platen, having automatically moved aside after a cut to permit replacement of the die by the operator, is automatically caused to return toward the next operative position. 'In this mode, with suitable timing of the sequence of movements, the platen will arrive over the die immediately after the operator has iinished replacing it and the vertical cutting stroke may then be tripped by the operator or by suitable automatic means without having to await the return transversing movement of lthe platen.

It is accordingly an object of the present invention to provide a cutting press of the type having a laterally movable platen in which the platen, after pressing the die through the work piece, is automatically caused to withdraw transversely of the work support to clear the die and then return in the opposite direction for bringing the platen over the die in its new position.

It is a further object of the present invention to provide in a cutting press control means whereby the transverse and vertical movements of the platen are automated to a degree where the operator may give his full attention to the manipulation of the die.

To these ends and in accordance with a feature of the invention, there is provided in a cutting press of the foregoing type having a platen, a work support, means for supporting the platen for movement perpendicular to the work-engaging surface ofthe work support and transversely thereof and power means for providing said movements, in combination therewith, control means for the power means comprising (a) stroke contr-ol means having tripl means actuatable for initiating movement of the platen toward the work support to press a die'there'on and stroke terminating means responsive to a predetermined signal for terminating the movement of the lplaten, toward the work support and for initiating movement of the platen away from the work support and (b'),travelrse control means operative in response to said signal f or causing transverse retreat movement of the platen to clear .the die and thereafter transverse return movement of `said platen in the opposite direction.

In accordance with a further feature of the invention the return movement termination is provided by the trip means which is also operative for initiating the perpendicular movement of the platen'. l l

lIn accordance with still another feature of the present invention the Itrip means electric signal is provided by a die sensor carried by the platen adjacent its leading edge which is operative in response to movement over a cutting die. In accordance with yet another lfeature of the present invention the control means includes a hand sensor including a sensing element or plate carried by the platen adjacent its leading edge which is -operative in response to sensing the proximity of a portion of lthe'body of the operator in the path of movement of the platen to effect interruption of the return movement of .the platen.

In accordance with yet another feature of the i-nvention, the hand sensor is operative for distance discrimination between two zones of different extent from a sensing plate. This control is operative in response to sensing the body portion of the operator in the farther zone in order to interrupt return movement of the platen. It is operative in response to sensing of said body portion in the nearer zone to effect movement of the platen away from the |body portion toward its inoperative position.

Other lfeatures and advantages of the invention will best be understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a front elevation of a cutting press embody'- ing the present invention;

FIG. 2 is a side elevation partly in vertical section taken on line IiI-II of PIG. 1;

FIG. 3 is a plan view partly in section of a portion of the press shown in IFIG. 1, on an enlarged scale;

FIG. 4 is Ia diagram of the hydraulic system for the press of lF'IG. 1;

lFIGS. 5A and 5B, ltogether illustrate a diagram of the electric circuits of the control for the press of FIG. 1;

|FIG. `6 is a detailed schematic of a portion of the control indicated in FIGS. 5A and `S'B;

FIG. 7 is a hydraulic diagram of a modification of th control means for the press;

FIGS. A8A and 18B, together illustrate an electrical diagram of a modified control operating with the hydraulic system of FIG. 7;

FIG. 9 is an electrical diagram of a die sensor circuit;

'FIG. 10 isa chart relating to IFIGS. -8A and 81B showing the condition of relay coils and relay contacts at different portions of a cycle of movement of the press;

FIG. l1 is an angular view of a sensing head comprising a portion of a hand sensor;

FIG. 12 is a vertical section of the apparatus shown in FIG. 11;

FIG. 13 is a horizontal section of the apparatus shown in FIG. lll; and

FIG. 14 is an electrical diagram of a hand sensor employing the sensing head shown in FIG. 11.

Referring to FIGS. 1, 2 and 3, the .illustrative press comprises a frame 10 carrying a work support 12 provided 3 with a conductive cutting pad 13 adaptednto receive work pieces 14 for cutting into work parts by means of a die 16. The upper portion 18 of the frame 10 is provided with rail means 20 extending horizontally above the work support 12 for supporting a carriage 22 on rollers 24 journaled therein.

The carriage 22 supports a bearing tube 26 in which a platen bearing cylinder 28 is vertically slidable for raising and lowering a platen 30 in cutting strokes for pressing thevdie 16 through the work and against the pad 13. Rotation of the platen bearing cylinder is prevented by the provision of four vertical slide tubes 32 connected at their bottom to the platen L30 and journaled through the carriage 22. Platen return springs 34 extend through the slide tubes from the platen to the upper portion of the bearing tube 26 where they are secured to brackets 36- carried on a bearing tube cover 3S bolted to the tube 26. A hollow piston rod V extends downwardly from the cover 38 and carries at its lower end a piston 42 adapted for a sliding fit with the inner surface of the cylinder 28.

Means comprising a flexible hydraulic hose 44, one end of which is connected to piston rod terminal fittings 46, is provided for connecting, through the piston rod, the chamber beneath the piston with a source of pressure fluid through a pump -48 driven by electric motor 50 and iiywheel 50A so that when pressure iiuid is admitted to the chamber the platen is caused to descend against the force of the springs 34 and finally the cutting force of the die 16.

Movement of the carriage to eliect movement of the platen 30 transversely of the work support is provided by a traverse screw 60 journaled in bearings 62 at opposite ends of the frame portion 18. The screw 60 has threaded engagement with a nut 64 disposed between parallel ears 66 extending rearwardly of the bearing tube. The screw 60 is driven by a reversible hydraulic motor 68.

Referring now to FIG. 4, the hydraulic system of the press comprises the electric motor 50 and flywheel SGA driving the pump 48 for supplying hydraulic uid to the piston 42 and cylinder 28 for providing ver-tical movement of the platen. The motor 50 drives .a second pump 80 for supplying pressure fluid to the traverse motor 68. Both pumps are supplied from a sump 82. Pressure fluid from the pump 48 is supplied to the cylinder 28 through a conduit 84 and a solenoid valve SV1 which is open only when the solenoid is energized. A high pressure solenoid valve comprising a piloted discharge valve 86 and a solenoid pilot valve 88 normally maintains the pressure in the conduit 84 at a minimum inoperative to effect downward movement of the platen, by discharging the conduit 84 to the sump unless the solenoid of the valve 88 is energized at which time the high pressure valve closes. The pump 80 provides pressure uid to the motor 68 through a conduit 90, a fast-slow solenoid valve 92 introducing a selected one of two restrictions 94, and a right-left solenoid valve 96 having solenoids 96A and 96B controlling the direction of transverse movement. Relief valves 98 across the motor conduits are provided to limit the motor torque, for example in the even-t of mechanical stoppage of traversing movement, and also to dynamically brake the traversing movement.

FIGS. 5A and 5B show diagrammatically the electric circuits of the press control. In accordance with a feature of the invention, the control provides means for selecting the mode of operation of the press from several modes provided which range from essentially manual to fully automatic through several degrees of automated cycles. The intermediate cycles are termed semi-automatic indicating that the head or platen moves horizontally and vertically automatically, while the placing of the die and the removal of the work isdone manually. Circuit lines are numbered in a column at the left while a column on the right indicates the lines where the contacts of the various components are located, the underlined numbers indicating closed contact points.

The schematic of FIGS. 5A and 5B is based on symbols such as those used by the LLC. standards, and is tied into the hydraulic circuit of FIG. 4 by appropriate labels. Accordingly, reference numerals will be used chiefly for identifying the main operating components and assemblies.

The control circuit comprises a transistorized stroke initiating and terminating control circuit 500 (line 4) of the type disclosed in United States Patent No. 3,204,506, issued Sept. 7, 1965 in the name of Frank W. Reinhold (see FIG. 6B of said patent). Briefly, the circuit shown in FIG. 6 shows how closure of contact ICR causes energization of ZCR and the solenoidl valve 88 and shows a selector switch for selecting a predetermined stroke terminating signal from closure of a lower limit switch or from platen to cutting pad conductivity through a die.

The circuit of FIGS. 5A and 5B includes a number of adjustable timers, e.g. 502 (line 9) which operate after closure of their operating contacts, e.g. 2CR (line 8) to transfer their contacts after a predetermined time period.

The circuit also includes a hand sensing relay circuit 504 (line 34) whose circuit is shown in detail in FIG. 14 and which comprises a sensing head 510 (FIGS. 11, 12 and 13) carried by the platen 30 at each lateral edge (FIG. 1). The hand sensor has a quarter wave length antenna comprising a capacity plate 512 carried by the sensing head 510 which acts as a capacity sensor, an RF oscillator 51,4, two amplifiers 516, 4518 and two switching circuits 520 and 522.

With the sensor mounted on the head, the oscillator 514 is tuned to resonance by adjusting the capacitor in its tank circuit for minimum current. The antenna is then tuned to resonance hy varying the capacitor 524 in its circuit for maximum current. Accordingly, any change in capacitance sensed by the plate 512 will reduce the current drawn by the oscillator. The change in oscillator current is communicated through a resistance bridge 526 to the amplifiers which are adapted to respond to different changes in oscillator current to effect their switching function. While the detector is particularly adapted for use with a modication of the control circuit illustrated in FIGS. 8A and 8B and the schematic of FIG. 14 is tied specifically into the latter schematic since the sensor is able to distinguish between positions of the operators hand differently spaced from the capacitor plate, the control is suitable for use with the circuit of FIGS. 5A and 5B where only one level of sensitivity is employed. It is noted that the sensor head is mounted on the carriage in an attitude such that the capacitor plate does not sense a die carried by the work support.

The circuit of FIGS. 5A and 5B also includes a die sensor whose circuit is illustrated in FIG. 9 and which employs sensing heads 600 (FIGS. l, 2 and 3) carried by the platen adjacent the leading and trailing edges and comprising a ferrite core coextensive with said edges. The core has a cross section in the form of the letter E, the core being mounted with the legs extending downward with their ends llush with the lower Surface of the platen. Again the schematic of FIG. 9 is tied into the control circuit modification of FIGS. SA and 8B, but is suitable for use in the circuit of FIGS. 5A and 5B where it is indicated at line 64.

The mode switching system comprises a bank of single or double pole push button switches interlocked so that no two buttons can be depressed at the same time and arranged so that operation of any button will temporarily disconnect the D.C. supply, dropping out any latched relay.

The Move-Up switch (line 10) permits application of power to the solenoid valve SVI for moving the platen upwardly. The Move-Left switch (line 40) energizes the relay 4CR whose contacts at line 24 energize the Move- Lef solenoid of the Right-Left solenoid valve 96 and via the contacts in line 31 energize the pilot valve 102 of the high pressure valve 100 (FIG. 4). The Move- Right switch, line 41, provides corresponding traverse in the opposite direction through the contacts of lSCR. lA double pole 'double throw switch (lines 25 and 27) enables the operator to select the direction in .which the heading will-move immediately following a cut..The upper armature is shown in the move-left-after-cut position aud, following a pause of the head in itsv inoperative position during a cycle, the move-right-after-pause position. Thelower armature is shown in themove-right-after-cut and move-left-after-pause position. Mode L1:'Manual.--This mode providesfor operation of the press in which the operator, after positioning the die, positions the platen over the die using the Move- Left or"Move-Rigl1t buttons. For this mode the operator actuates Mode l switch, thus opening line 17. The operator thentpresses the trip buttons of line 1. which, through 1CR causes Q5 (FIG. 6) to conduct and thus initiates operation of the stroke control circuit 500. The platen moves down onto the die, cuts, and then, by reason either of the die contacting .the conductive cutting-pad, or by closure of a lower limit switch, depending on the position of a selector switch shown at lines 6 and 8, the platen moves upward. The operator then uses either one of the Move-Left or Move-Right buttons to move the head aside. Upward movement of the platen is determined by the stroke timer 502 initiated lby reclosure of the 2CR contacts of line 8. A traverse delay timer of line 13 is also caused to go through its cycle, but is ineffective to latchv in SCR because of the open mode switch.

Mode 2: Improved manual.-This mode, provided by actuation of the Mode 2 switches, is similar to Mode l with the additional feature that when the traverse delay timer of line 13 transfers its contact TDT (line 15), SCR latches through its own contact in line 17 and initiates a traverse timer (line 20) causing the head to move to the side at the fast speed until the traverse timer times out when contacts 'IT in line 2S open.

- Mode 3: Semi-automatic (catching head on ljly) provded'by actuating the Mode 3 switch-After -movement ofthe platen to the side under the control of the traverse timer as in Mode 2, and the opening of the contacts TT in line 2S, a pause timer (line 37) times out closing contacts in line23 to effect movement of the traveling head back toward the original position of the die at the slow speed. The head will continue moving until the operator presses the trip switches for the Anext cut. The-operator presses a holding button to drop out relay SCR, or one ofthe limit switches is opened when the traveling head reaches the end of its travel. v vMode 4: Semi-automatic with timed return-For this mode, the Mode 4 switch (line 42) is closed energizing M4CR opening contacts in line 16 to incorporate normally closed return traverse contacts RTT of line 18 in the energizing circuit of SCR. Accordingly, when the return traverse timer of line 39 times out during return movement of the head, the contacts RTT draw open dropf ping out SCR and stopping the return movement.

Mode 5: Semi-automatic (die sensed only during return traverse).-This mode is provided by. actuating the Mode 5 switch of line 45 energizing MSCR introducing into line 18 normally closed contacts of relay 9CR. Also, the die sensing selector switch of line 56 is actuated. Hand sensing can be used with this mode for improved operator safety and if required, actuate hand sensing selector switches ofthe hand sensor 504. In the operationof the press in this mode, after actuationof the trip switches the platen is moved downward to cut and returned while the head moves to the side at fast speed, pauses and returns at slow speed as in Mode 3, until the die sensor headpasses over the leading edge of the die. The die sensor relay contacts in line 56 then close, charging the capacitor. The head continues traveling and the sensor moves over the center of the die beyond the sensing iield of the sensor which drops out and the normally closed die sensor contacts of line 57 connect the charged capacitor across relay 7CR which latches in through itscontacts in line 58. 7CR also initiates a die sensordelay timer in line 62 which, after timing out, closes contacts in line 58, energizing relay 9CR which opens normally-closed contacts in line 18, stopping the traverse motion.

Mode 6: Semi-automatic die sensed as head moves in both directions-In this mode the .retreat of the head, as well as the return thereof, is controlled by the die sensor. For this mode the Mode 6 switch, lines 44 and 45, is actuated, energizing both MSCR and M6CR. MSCR incorpo.- rates 9CRnormally closed contacts into line 18 while MGCR opens line-2S, changes the pause timer initiation from TT to 8CR and closes contacts in line 30. The die sensing selectorswitch of line 56 is actuated. In operation, after tripping, the platen is moved in its cutting stroke and after the traverse delay timer times out contacts TDT eflfect latching of SCR which initiates traverse movement of the traveling head. As the die sensor passes over the leading edgeof the die, the Vdie sensor relay closes, charging the capacitor in line 56. As the head continues, the ferrite core of the sensing head 600 moves over the center of the die. At this point a smaller length of the die is withintthe magnetic field, reducing the sensing coupling to a point where the die sensor relay drops out, this energizing relay 7CR initiating the die sensor delay timer of line 62 which on timing out energizes relay 8CR through contacts in line 58. 8CR opens line S0 stopping the head and initiates the pause timer which times out and initiates return of the traveling head at slow speed. This movement continues until the die sensor passes over the die, after which the return movement is stopped as in Mode 5.

Mode 7: Semi-automatic (die sensed only during return traverse and with inactive part of machine cycle occurring when the machine head s away from the de).-For this mode the Mode 7 switch is actuated, energizes MSCR and M7CR.' M7CR closes contacts in line 54 and reroutes line 28 to pass through 6CR normally open contacts in line 27. The pause timer is set to zero delay and the die sensing switch is actuated. The trip buttons are pressed and the platen moves downward and upward in a cutting stroke and the traveling head is moved aside as formerly at-high speed until the traverse timer -times out, cutting olf the power from the traverse valves and initiating the pause timer. This timer times out and deenergizing 7CR, energizes 10CR and closesl contacts in line 28. The machine is now inactive with the head away from the die and the circuit is conditioned so that actuation of special trip buttons (line 54) will initiate one full cycle by energizing relay `6CR. 6CR then latches and closes contacts in line 27 effecting transverse return movement of the head at slow speed. The head continues until the die sensor passes over the leading end oi?.4 the die, charging the capacitor and then over `the center of the die where the die sensor drops out, latching in 7CR which initiates the die sensor delay timer. The timer closes contacts, pulling in relay `9CR which drops out SCR stopping the traverse motion. SCR, in combination with 6CR, energizes ICR to eifect a cutting stroke after which the head is moved away from the die at fast speed as previously described.

Mode 8: Semi-automatic (die sensed as head moves in both directions and with the machine inactive at the sde).-In this mode the Mode 8 switch is closed, energizing MSCR, M6CR and M7CR. MSCR incorporates M9CR normally closed contacts in line 18; M6CR opens line 23, changes pause time initiation to 8CR and closes contacts in line S0; M7CR incorporates 6CR normally open contacts in line 27 and closes contacts in line 54. The pause time is reset to zero and the die sensing switch is actuated. In the operation, the regular trip buttons are pressed to cycle the machine as in Mode 7 to a condition where it is inactive with the head away from the die and the circuit conditions so that actuation of the special trip buttons will initiate one full cycle. It is believed from the foregoing descriptions that the operation of the conout detailed repetition. y

Mode 9: Full semz'automatc4 (die sensed only as'head moves toward the die).-For` this mode the Mode 9 switch is actuated energizing MSCR and closing the switch contacts in line 50. MSCR incorporates M9CR contacts into line 18, the die sensing selector switch is actuated and so are the hand sensing selector switches of lines 28 and 30. In operation, upon closing the trip switches of line 1, the platen -is moved in a cutting stroke and after the traverse delay timer times out the traveling head is moved aside at fast speed until the traverse timer times out as previously described.` Then, after the pause timer times out energizing CR and closing the contacts in line 28, the head moves back toward the die at the slow speed until the die sensor passes over the die to its center, energizing 7CR. 7CR initiates the die sensor delay timer energizing 9CRXO relay, 9CRpulls in its'normally closed contacts in line 18 are opened, `thus dropping out 3CR and stopping the traverse motion. Also, 7CR, SCR and `9CR are then dropped'out. 3CR, in combination with MQCR, energize lCR and the system continues to cycle until the hold buttons are depressed. Should the operators hands be in the way of the platen during its return traverse, the traverse motion will be stopped by operation of the hand sensor until the path is clear. Mode 10: Full semi-automatic (die sensed as head moves in both drectons).-This mode is provided by actuating the Mode 10 switch energizing MSCR, M6CR and closing contacts in line 52. The die sensing selector switch and the hand sensing selector switches are actuated. This mode provides a continuing cycle controlled by the die sensor which will be clear from the preceding descriptions of other modes. However, if the operators hands get in the way of the return movement of the head, the traverse motion will stop until the path is clear. The operation can be stopped by pressing the hold button.

Mode Il: Full automatic using time increments- In this mode the die-is carried by the platen. The Mode l1 switch is actuated energizing M9CR and M11CR. In the operation of this mode, after actuation of the trip switches, after the platen has 4moved down until stroke termination and then up `until the stroke timer times out and sideways after the rtraverse delay timer times out, the traveling head moves-to the side for the preset distance determined by the traverse timer. When this times out the con'- tacts 'IT in line 23 stop the traverse motion and drop out SCR whose normally closed contacts in line 2 close to initiate another stroke. l

Referring now to the modification of -the control disclosed in the schematic of FIGS. -SA and 8B, a semiautomatic mode of operation is provided in which the head starts to move toward the die when the trip switches 202 in line 1 are actuated and will continue to travel toward it until the die sensor has gone over the die. When the platen is over the die, the head comes to a stop as previously described and the platen moves down on the die and makes the cut. After the cut is made the platen lifts up to a predetermined height, the head moves away from the 4die a predetermined distance, stops there for a predetermined time and then starts to return toward the die.

A During the above cycle when the head starts moving away after the up action and when it has cleared the die, the operator reaches for the die, removes the cut material and places the die in a new position. While the die is being relocated, the head may beon'the return portion of the cycle. If the operators hand is not near the die the head will continuato go over the die. However, if the operators hand is near the die, but is more than a predetermined distance, for example, 7", away from the sensing plate (in Zone 1 of the two-zone hand sensor), the head will continue to travel toward the die until the distance between the hand and the plate is equal to the predeterminedI distance, i.e., 7" in the example, then the trol toprovide the Mode 8 cycle will be apparentwithhead'will stop'. If the hand is removed the-head goes over the die-and completes the cycle. However, if the hand is moved toward the head and enters Zone 2 .at afse'cond predetermined distance, for example 3" less than the Zone 1 distance, thenV the head moves away from the -hand a preset distance and comes to a stop. It remains there as long as the hand in the example is more than-3" but less than v7" away from it. Thus smooth operation` of the head is accomplished by providing a dead zone (here 4") Where the head stays stationary when the hand is moved within the zone. Again, when the hand -is removed the head returns over the die and completes the cycle, In Vthe operation of the hand sensor, just asthe hand enters Zone 1, the zone which extends farthestfrom the capacity plate, its amplier 516 deactivates K9 in the switch circuit 520 which, in turn, through sequencing of the Coast Timer and energizing K11, stops the'head. No further action of the head will take place if the hand is between Zone l and Zone`2i.e., is in the dead zone, because biasing of they Zone 2 amplifier is set to deenergize the switching circuit 522 at minimum current drawn by the-oscillator.4 Now, if the operators hand enters-Zone 2, its amplifier deactivates the Zone 2 switching circuit which sequences the head to move away from the hand a set distance determined by the 3".Coast Timer which would place the hand in the dead zone. When thehand is removed the oscillator becomes loaded and. draws more current, thus activates theamplifiers and switching circuits to allow the head .to return to the die.

The Aoperation of the control circuit of FIGS.` -SA and 8B is believed to be clear from the schematic. However, a relay chart is provided in FIG. 10 to facilitate an understanding of the operation by showing the conditions of the relays and their contacts at different stages of :the machine cycle. The relay contacts shown in FIG. 10 are arranged in columns under the functions Down, Up, Away and Return. It will be understood that each horizontal group under a given function represents a logic expression in Boolean algebra. Thus all the contacts under a given function-must be closed in order for the function to be initiated, except where an or term is indicated.

Having thus described our invention, what we claim as new and desire to secure byv Letters Patent of the United States is:

1. In a die cutting press having a work support,a platen, means for supporting the platen for movement toward and away from the work support and transversely thereofand power means for effecting such movements, in combination therewith, control means operatively connected to said power means -for causing said power means to effect cyclical movement of the platen, said control means comprising t (a) stroke control means having trip means actuatable to vcause movement of the platen toward the work support and having stroke terminating means responsive to a lpredetermined signal for interrupting said movement and for causing movement of the platen away from said support, and (b) traverse control means operative in lresponse to said predetermined signal forcausing transverse movement ofthe platen of retreatin one direction for a predetermined distance and then of return in the opposite direction. 2. Apparatus as in claim-1in which said traverse control .means additionally-has means operative to interrupt the return movement ofthe platen. `3.- Apparatus as in claim 1 in which said traverse control means additionally has means operative to interrupt the return movement vofthe platen after a predetermined return distance. I v t 4. Apparatus as in claim 1 in which said traverse control means additionally comprises variable'timing means for at least one of 'said traverse'movements and is opera tive vto-interrupt -said one movement after a predetermined'time'interval.

5. Apparatus as in claim 1 in which said traverse control meansadditionally has means operative at a predetermined position of the platen in its path of transverse movement to interrupt the return movement of the platen.

6. Apparatus as in claim 1 in which said traverse c'ontrol means additionally includes means operative in response to actuation of said trip means to interrupt the return movement of the platen.

7. Apparatus as in claim 1 wherein the traverse control means additionally comprises means for providing a speedwof retreat greater than the speed of return.

8. Apparatus as in claim 1 wherein the traverse control means additionally comprises timing means operative to establish a predetermined variable interval between the movements of retreat and return.

9. Apparatus as in claim 1 wherein the traverse control means includes a hand sensor having a sensing element carried by the platen, the traverse control means being operative in response to movement of the element into predetermined proximity With a portion of a human body to interrupt the return movement of the platen.

10. Apparatus as in claim 9 wherein the traverse control is responsive to a body portion in a iirst zone extending a given distance from the sensing element to interrupt the return movement of the platen, and is also responsive to a body portion in a second zone extending a shorter distance from said element to cause the platen to retreat.

11. Apparatus as in claim 1 in which said control means additionally comprises die sensing means including a sensing element carried by the platen, said control means being operative under the control of said sensing means to interrupt said return movement and initiate movement of the platen toward the work support in response to movement of said element over a die as the platen passes thereover on its return movement.

12. Apparatus as in claim 11 in which the traverse 10 control means additionally includes means controlled by die sensing means in response to movement of the platen clear of the retreat portion of the traverse cycle to interrupt the movement of retreat.

13. In a die cutting press having a platen, a work support, means for supporting the platen for movement toward and away from the work support and'pfor movement transversely of said support, -power means for providing said movements of the platen, in combination therewith, control means for said power means comprising means for initiating movement of said platen transversely of said support to a predetermined position to bring said platen over a die positioned on the work support, sensing means operative in response to disposition of a body portion in a zone adjacent said platen for temporarily interrupting said transverse movement of the platen until said body portion is out of said zone, means comprising a die sensor operative responsively to movement of the platen over a die on the work support and operative at said predetermined position for initiating downward movement of the platen toward the work support to press said die through a work piece, stroke terminating means responsive to a predetermined electrical signal for interrupting the movement of the V4platen toward the work support and means acting in response to said last signal for thereafter effecting movement of the platen away from the work support and transversely thereof.

References Cited UNITED STATES PATENTS 2,718,260 9/1955 Oakes 83-68 2,929,969 3/ 1960 Denysiuk 340-258 X 3,204,506 9/ 1965 Reinhold 83-534 3,212,382 10/1965 Haas 83-537 ANDREW R. JUHAsz, Primary Examiner.

Claims (1)

13. IN A DIE CUTTING PRESS HAVING A PLATEN, A WORK SUPPORT, MEANS FOR SUPPORTING THE PLATEN FOR MOVEMENT TOWARD AND AWAY FROM THE WORK SUPPORT AND FOR MOVEMENT TRANSVERSELY OF SAID SUPPORT, POWER MEANS FOR PROVIDING SAID MOVEMENTS OF THE PLATEN, IN COMBINATION THEREWITH, CONTROL MEANS FOR SAID POWER MEANS COMPRISING MEANS FOR INITIATING MOVEMENT OF SAID PLATEN TRANSVERSELY OF SAID SUPPORT TO A PREDETERMINED POSITION TO BRING SAID PLATEN OVER A DIE POSITIONED ON THE WORK SUPPORT, SENSING MEANS OPERATIVE IN RESPONSE TO DISPOSITION OF A BODY PORTION IN A ZONE ADJACENT SAID PLATEN FOR TEMPORARILY INTERRUPTING SAID TRANSVERSE MOVEMENT OF THE PLATEN UNTIL SAID BODY PORTION IS OUT OF SAID ZONE, MEANS COMPRISING A DIE SENSOR OPERATIVE RESPONSIVELY TO MOVEMENT OF THE PLATEN OVER A DIE ON THE WORK SUPPORT AND OPERATIVE AT SAID PREDETERMINED POSITION FOR INITIATING DOWNWARD MOVEMENT OF THE PLATEN TOWARD THE WORK SUPPORT TO PRESS SAID DIE THROUGH A WORK PIECE, STROKE TERMINATING MEANS RESPONSIVE TO A PREDETERMINED ELECTRICAL SIGNAL FOR INTERRUPTING THE MOVEMENT OF THE PLATEN TOWARD THE WORK SUPPORT AND MEANS ACTING IN RESPONSE TO SAID LAST SIGNAL FOR THEREAFTER EFFECT ING MOVEMENT OF THE PLATEN AWAY FROM THE WORK SUPPORT AND TRANSVERSELY THEREOF.

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