US3919907A

US3919907A - Punching machine with automatic cycle control

Info

Publication number: US3919907A
Application number: US520362A
Authority: US
Inventors: Lee Kindgren
Original assignee: W A WHITNEY CORP
Current assignee: W A Whitney Co
Priority date: 1974-11-04
Filing date: 1974-11-04
Publication date: 1975-11-18
Anticipated expiration: 1992-11-18

Abstract

A power-rotated cam stores the time required to advance a punch press from a home position to a punching position and causes the press to be stopped in the home position when the press is returned toward the home position after punching a hole.

Description

United States Patent [191 Kindgren [451 Nov. 18, 1975 PUNCI-IING MACHINE WITH AUTOMATIC CYCLE CONTROL [75] Inventor: Lee Kindgren, Rockford, ill.

[73] Assignee: W. A Whitney Corporation,

Rockford, Ill.

22 Filed: Nov. 4, 1974 21 Appi. No: 520,362

[52] US. Cl. 83/368; 83/370; 83/527; 83/530; 83/560 [51] Int. Cl. B26D 5/02; B26F H14 [56] References Cited UNITED STATES PATENTS 2,548,562 l0/l95l Slathar 83/71 X if ='Z/ I 1 ".1- I IF 1 l2/l974 Cantelia 83/530 l/l975 Valente 83/560 X Primary ExaminerJ. M. Meister Assistant Eraminer-Fred A. Silverberg Attorney, Agent, or Firm-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd.

[57] ABSTRACT A power-rotated cam stores the time required to advance a punch press from a home position to a punching position and causes the press to be stopped in the home position when the press is returned toward the home position after punching a hole.

6 Claims, 2 Drawing Figures Sheet 1 0f 2 3,919,907

US; Patfint Nov. 18, 1975 PUNCHING MACHINE WITH AUTOMATIC CYCLE CONTROL BACKGROUND OF THE INVENTION This invention relates to an automatic cycle control for a punching machine and particularly for a machine of the type which is adapted to punch holes in an elongated member such as an I-beam having a horizontal web with upstanding and depending side flanges. Typically, the machine includes upper and lower punch presses mounted on a vertically movable carriage and respectively adapted to punch holes in the upper and lower flanges of the beam. By moving the carriage vertically, the presses can be located so as to punch holes at different elevations in the flanges.

In the usual punching operation, the presses are initially adjusted in a vertical direction to a home position in which the presses are centered with respect to the web of the beam and in which upper and lower gaging probes associated with the presses will clear the web when the latter is advanced to the presses. The gaging probes then are adjusted to establish the proper vertical location for the holes in the flanges. Upon initiation of the punching cycle, the carriage moves vertically until one of the probes contacts the web and stops the carriage. Thereafter, the hole is punched and the carriage returns the presses to the home position. If a hole is to be punched in the other flange, the carriage is moved vertically in the opposite direction and then returns the presses to the home position after punching of the hole.

When the machine is changed over to run beams having flanges with a different height, it is often necessary to re-adjust the home position of the presses so that the presses and the gaging probes will not engage the web as the beam is advanced. Accordingly, the home position of the presses is not necessarily the same from run to run but indeed may change when the machine is set up to operate on beams of different sizes.

SUMMARY OF THE INVENTION The general aim of the present invention is to provide a punching machine of the above character with a new and extremely simple automatic cycle control which returns the punch presses to their last-established home position at the completion of each punching cycle even though the home position may change from cycle to cycle. lmportantly, the automatic return to the home position is effected without need of adjusting the control when the home position is changed.

A more detailed object is to achieve the foregoing through the provision of a control which stores the time interval required to advance the presses from the home position to the punching position and then automatically stops the return of presses after the presses have been returned through substantially the same time interval. Because the control operates as a function of the time required to move the presses and not as a function of their position, the control may return the presses to the home position regardless of the location of the home position.

The invention also resides in the simple, low cost and trouble-free construction of the control and in the use of the same control for effecting cycling of both presses of the machine.

These and other objects and advantages of the invention will become more apparent from the following de- 2 tailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of an exemplary punching machine equipped with a new and improved automatic cycle control embodying the unique features of the present invention. This view shows the machine somewhat schematically and partially in cross-section.

FIG. 2 is a diagram of an electrical circuit with which the automatic cycle control is associated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the invention is embodied in machine tool apparatus and particularly in a punching machine 10 having upper and

lower punch presses

11 and 12. The latter are adapted to punch holes in the inboard upper and lower flanges 13 and 14, respectively, of an elongated [shaped member or beam 15 having a horizontal web 16. The beam is supported for lengthwise advancement by a power-driven roller conveyor 17 and is periodically stopped at the presses in a punching station where one or more holes are punched in either or both flanges before the next advance of the beam.

Each of the'presses 11 and 12 comprises a C-shaped frame 19 having a punch 20 and a die 21 adapted to be located on opposite sides of the flange 13, 14. A double-acting hydraulic actuator 22 is mounted on each frame and includes a reciprocable ram 23 for moving the respective punch into and out of telescoping relation with the alined die and thus effect punching of the holes.

Both press frames 19 are supported rigidly on a common carriage 24 which is guided for up and down reciprocation on the main frame 25 of the machine 10. By adjusting the carriage upwardly and downwardly, the punches 20 may be positioned at various elevations relative to the flanges 13, 14 and thereby punch the holes at selected vertical points. Adjustment of the carriage is effected by a double-acting hydraulic actuator comprising a cylinder 26 which is anchored to the main frame 25 and which slidably receives a reciprocable rod-27 connected to the carriage 24.

To establish the vertical location of the holes, the machine 10 includes upper and

lower gaging probes

29 and 30 which are adapted to engage opposite sides of the web 16 of the beam 15 and stop vertical movement of the carriage 24 when the latter is advanced to place one of the

presses

11 and 12 in its punching position. The probes are carried on the press frames 19 and thus move vertically in unison with the presses l1 and 12 whenever the latter are shifted. In addition, the vertical position of the probes may be adjusted independently of the presses by manually turning a handwheel 31 to shift the probes through equal distances but in opposite directions on the press frames. In this way, the elevation of t the probes relative to the elevation of the punches 20 may be changed so as to stop the advance of the carriage 24 when the punches are at different selected vertical punching positions.

In first setting up the machine 10 for operation on a given beam 15, the operator turns the handwheel 31 to establish the desired gage setting for the probe 29 and- /or the probe 30. The operator then manually adjusts the carriage 24 in a vertical direction to a home or starting position in which the presses and the probes are substantially centered with respect to the web 16 of the beam. In other words, the carriage is initially adjusted to a position in which the presses and the probes are spaced equidistantly from opposite sides of the web so that the presses and the probes will not engage and rub against the web when the beam is advanced. Manual adjustment of the carriage 24 in a downward direction may be effected by closing a push button switch PB-D (FIG. 2) to energize a solenoid SOL-D. This causes shifting of a control valve (not shown) to admit pressure fluid into the upper end of the cylinder 26 and produce downward movement of the carriage. Similarly, closure of a push button switch PB-U energizes a solenoid SOL-U and effects reverse shifting of the control valve so as to admit pressure fluid into the lower end of the cylinder and cause upward shifting of the carriage. The flow of pressure fluid into and out of the cylinder is regulated by pressure compensated flow control valves 35 (FIG. 1) which meter the pressure fluid in such a manner as to cause the upward velocity of the carriage to be substantially equal to the downward velocity.

After the

presses

11 and 12 have been located in the home position and the beam 15 has been located in the proper linear position, the machine may be placed through an automatic cycle to effect punching of a hole. Assuming that a hole is to be punched in the upper flange 13, such an automatic cycle begins with downward advance of the carriage 24. to shift the upper press 11 downwardly from its home position toward its punching position. As the press reaches its punching position, the upper probe 29 engages the upper side of the web 16 and stops further downward movement of the carriage. Thereafter, the actuator 22 of the upper press is cycled to first extend its ram 23 and effect punching of the hole and then to retract the ram and pull the punch 20 out of the die 21. The carriage then is returned upwardly to bring the presses back to the home position whereupon the carriage stops until the initiation of the next cycle. If that cycle involves the punching of a hole in the lower flange 14, the carriage first advances upwardly to shift the lower press 12 from its home position to its punching position, the upward advance of the carriage being stopped by engagement of the lower probe 30 with the lower side of the web 16. After the lower press has punched the hole, the carriage is returned downwardly to shift the presses back to the home position.

The operator may punch several holes in the beam at different elevations and linear locations and then bring a new beam to the machine 10. If the new beam has flanges of a different height than the previous beam, the web of the beam will be located at a different elevation. Thus, the operator may find it necessary to adjust the carriage 24 manually with the push button switches PB-D or PB-U in order to set the

presses

11 and 12 in a new centered or home position so that the presses and the

probes

29 and 30 will clear the web of the beam when the latter is advanced. Accordingly, the home position is not fixed but instead is changed when the machine is set up to run a beam of a different size.

According to the present invention, provision is made of a very simple and low cost control 40 (FIG. 2) which, during automatic cycling of the machine 10, always causes the

presses

11 and 12 to return to the home position even though the location of the home position might be changed from cycle to cycle. The control operates by storing the time interval required to 4 advance the presses from the home position and then by automatically stopping the return of the presses when the presses have been returned through a time interval equal to the interval required for advancement. Since the velocity of the presses is the same during their advance and return, the timing control is effective to stop the presses when the presses have returned through the same distance that they advance. By regulating movement of the presses as a function of time rather than position, the control causes the presses to always return to the last-established home position regardless of the particular location of the home position.

More specifically, the control 40 includes a reversible power-driven control element or switch actuator which herein is in the form of a cam 41 (FIG. 2) having a projecting lobe 43. The cam 41 is adapted to be driven by the armature A of a small d.c. motor M having a separately excited field, there being suitable reduction gearing (not shown) between the armature and the cam so that the cam will be rotated through less than one revolution during an operating cycle of the machine 10. When the

presses

11 and 12 are in the home position, the cam is angularly located as shown in FIG. 2 such that the lobe 43 holds a cam-operated switch CS in an open condition. As the presses are advanced toward the punching position, the motor M is energized and rotates the cam in one direction and at a substantially constant velocity to allow closure of the cam switch CS. When the presses are stopped in the punching position by the probe 29 or the probe 30, the motor is simultaneously stopped with the lobe spaced angularly from its original starting position. After the hole has been punched, the presses are returned toward the home position and, at the same time, the motor is energized to drive the cam reversely and return the lobe toward its starting position. The time interval required to move the lobe back to its starting position is the same as that which previously elapsed upon initial driving of the cam during the advance of the presses and thus, when the lobe opens the cam switch CS to stop return of the presses, the latter are located in the same home position.

The function of the control 40 in a complete operating cycle of the machine 10 now will be described. Let it be assumed that the operator has properly set the gaging probes 29 and 30 through the use of the handwheel 31 and has manually adjusted the

presses

11 and 12 to the proper home position through use of the push button switches PB-D or PB-U. Let it further be assumed that the operator wishes to use the upper press 11 to punch a hole in the upper flange 13 of the beam 15. To achieve this, the operator first pivots an upperlower press selector lever 45 (FIG. 2) counterclockwise to the upper or U position so as to move a switch wiper 46 into position to energize a relay U and effect closure of relay contacts U-l through U4. The operator then momentarily depresses a push button switch PB-S to energize a relay P and start the punching cycle. Relaycontacts P-l close to maintain the relay P in an energized state after the operator releases the start switch PB-S.

Energization of relay P also closes contacts P-2 to energize a relay PAD and close contacts PAD-l through PAD-4, the contacts PAD-4 closing preparatory. When contacts PAD-l close, the solenoid SOL-D is energized and causes the

presses

11 and 12 to begin advancing downwardly from the home position to the punching position. At the same time, a voltage of positive polarity is applied to the armature A of the motor M through the closed contacts PAD-2 and PAD-3. The motor thus begins rotating the cam 41, in one direction (assume clockwise) from its starting position so that the lobe 43 allows the cam switch CS to close and energize a relay CH whose contacts CH-l close. preparatory.

Downward advance of the presses l1 and 12 continues until the upper probe 29 engages the upper side of the web 16. Such engagement causes the probe to close a switch PS-U with such closure resulting'in energization of a relay RE to open contacts RE-l and close contacts RE-2 and RE-3, the closure of contacts RE-2 servingto seal in the relay RE. As contacts RE-l open,

relay P is de-energized to open contacts P-2 and deenergize relay PAD. Contacts PAD-1, PAD-2 and PAD-3 thus open to stop the downward advance of the presses and to de-energize the motor M.

Closure of the relay contacts RE-3 results in energization of a solenoid SOL-REU to shift a control'valve (not shown) for the hydraulic actuator 22 of the upper press 11 and to cause the ram 23 of such actuator to extend and effect punching of the hole in the upper flange 13. Upon reaching its extended position, the ram closes a limit switch RE-U to energize a relay RR whose contacts RR-l close to seal in the relay. Contacts RR-2 open to de-energize the relay RE and open the contacts RE-3 to stop further extension of the ram 23. Contacts RR-3 close to energize a solenoid SOL-RRU and effect reversal of the control valve for the actuator 22 and thereby cause retraction of the ram of the upper press 11.

As the ram 23 of the upper press 11 reaches its retracted position, the pressure in the hydraulic system of the actuator 22 builds up and causes momentary closure of a pressure-actuated switch SP. As a result, a relay PS is energized and opens its contacts PS-l to de energize relay RR and cause opening of contacts RR-3 and de-energization of solenoid SOL-RRU to stop fur ther retraction of the ram. Energization of the relay PS also results in the closing of contacts PS-2 and energization of a relay PRU through those contacts and the closed contacts CH-l. Contacts PRU-1 close to seal in the relay PRU around the contacts PS-2. When the solenoid SOL-RRU is de-energize'd, the pressure in the hydraulic system of the upper actuator 22 drops off to cause opening of the pressure switch SP and de-energization of the relay PS.

When the relay PRU is energized, its contacts PRU-2 close to energize the solenoid SOL-U and effect upward return of the

presses

11 and 12 from the punching position toward the home position. At the same time,

6 the motor M is not energized and thus the cam 41 remains in-its starting position and keeps the cam switch CS in its open state so that the switch will be compatible with the adjusted home. position. Accordingly, no adjustments need be made to the automatic cycle control 40 when the home position of the presses is adjusted. v

When the operator wishes to punch a hole in the lower flange 14 of the beam 15, the operation of the machine 10 is virtually the same as described above except that the

presses

11 and 12 first advance upwardly from the home position, are stopped in the punching position by the lower probe 30 and an associated limit switch PS-L, and then return downwardly to the home position after punching the hole. The selector lever 45 is placed in the L-position and the various relays which are operable during the cycle of the lower press are energized in the sequence of L, P, PAU, CH, RE, RR, PS

and PRD. De-energization' of the relays occurs in the relay contacts PRU-3 and PRU4 close to apply a voltage of opposite polarity to the armature A of the motor M and thus effect reverse or counterclockwise rotation of the control cam 41' toward its starting position. The cam reaches its starting position at the same time the presses l1 and 12 reach the home position and, as an incident thereto, the lobe 43 opens the cam switch CS to de-energize the relay CH. As a result, contacts CH-l open to de-energize the relay PRU, open the contacts PRU-2 and de-energize the solenoid SOL-U. Upward return of the presses thus is stopped so as to complete one punching cycle.

If the next cycle involves a beam of different size such as to require adjustment of the home position of the presses 1 l and 12, the operator effects such adjustment by closing the push button switch PB-D or PB-U. During adjustment of the home position in this manner,

sequence of P, PAU, RE, RR, PS, CH and PRD. The solenoids SOL-REL and SOL-RRL control extension and retraction, respectively, of the ram 23 of the actuator 22 of the lower press 12 while the switch RE-L senses when the lower ram has reached its extended position. 7

During the cycle of the lower press 12, the cam 41 first rotates in a counterclockwise direction in moving from itsstarting position and then rotates reversely during its return. Thus, the same cam and cam switch CS serve to control the cycles of both the upper press 11 and the lower press 12.

Those of ordinary skill in the art will appreciate that the circuit shown in FIG. 2 has been simplified greatly to facilitate ease of understanding and that the control circuit of a commercial machine will include various safety interclocks, anti-repeat interlocks, resets and the like. Also, the circuitry can be easily supplemented and modified to enable the lower press 12 to cycle immediately upon completion of the cycle of the upper press 11 and without need of the operator re-setting the start switch PB-S.

I claim as my invention:

1. Apparatus for punching holes in an elongated member, said apparatus comprising a conveyor for ad vancing said member along a generally horizontal path to a punching station, a punch press supported for movement in said punching station, means for causing said press to advance in one direction from a home position and for stopping said press when the latter reaches a preselected punching position relative to said member, means for causing actuation of said press when the latter is in said punching position thereby to effect punching of a hole in said member, means for thereafter causing said press to return in the opposite direction from said punching position at substantially the same velocity as undertaken by the press in advancing to said punching position, means for storing the time interval required for said press to advance from said home position to said punching position, and means for causing the return of said press toward said home position to stop when the press has been returned through the substantially same time interval whereby the press is stopped in said home position.

2. Apparatus as defined in claim 1 in which said storing means comprise a reversible power-driven actuator, said last-mentioned means comprising means positioned to be operated by said actuator when the latter is in a predetermined starting position, said apparatus 7 further including means for driving said actuator away from said starting position during advance of said press from said home position to said punching position and for stopping said actuator when said press reaches said punching position, and means for causing said actuator to be driven reversely toward said starting position during the return of said press toward said home position.

3. Apparatus as defined in claim 2 further including means operable to cause said press to advance and return without causing driving of said actuator whereby the home position of said press may be changed without changing the starting position of said actuator.

4. Apparatus as defined in claim 2 in which said actuator comprises a rotatable cam.

5. Apparatus for punching holes in an elongated member, said apparatus comprising a conveyor for advancing said member along a generally horizontal path to a punching station, a punch press located in said punching station and supported for vertical bodily movement relative to said member, means for causing said press to advance vertically in one direction from a home position and for stopping said press when the latter reaches a preselected punching position relative to said member, a rotary control element, a reversible rotary motor connected to rotate said control element, means for causing said motor to advance said control element in one direction from astarting position when said press advances from said home position and to 8 stop said element when said press stops in said punching position, a switching device associated with said control element and adapted to be switched from a first state to a second state as said element leaves said starting position, means for causing actuation of said press when the latter is in said punching position thereby to effect punching of a hole in said member, means for thereafter causing said press to return reversely toward said home position and simultaneously causing said motor to return said control element toward said starting position, said press and said control element returning at substantially the same velocities as undertaken by the press and the element, respectively, during their advance, said control element causing said switching device to switch from said second state to said first state when said element returns to said starting position, and means responsive to said switching device and operable to stop the return of said press and said control element when said switching device switches to said first state.

6. Apparatus as defined in claim 5 further including means operable to cause said press to advance and return without causing driving of said control element whereby the home position of said press may be changed without changing the starting position of said control element.

Claims

1. Apparatus for punching holes in an elongated member, said apparatus comprising a conveyor for advancing said member along a generally horizontal path to a punching station, a punch press supported for movement in said punching station, means for causing said press to advance in one direction from a home position and for stopping said press when the latter reaches a preselected punching position relative to said member, means for causing actuation of said press when the latter is in said punching position thereby to effect punching of a hole in said member, means for thereafter causing said press to return in the opposite direction from said punching position at substantially the same velocity as undertaken by the press in advancing to said punching position, means for storing the time interval required for said press to advance from said home position to said punching position, and means for causing the return of said press toward said home position to stop when the press has been returned through the substantially same time interval whereby the press is stopped in said home position.

2. Apparatus as defined in claim 1 in which said storing means comprise a reversible power-driven actuator, said last-mentioned means comprising means positioned to be operated by said actuator when the latter is in a predetermined starting position, said apparatus further including means for driving said actuator away from said starting position during advance of said press from said home position to said punching position and for stopping said actuator when said press reaches said punching position, and means for causing said actuator to be driven reversely toward said starting position during the return of said press toward said home position.

5. Apparatus for punching holes in an elongated member, said apparatus comprising a conveyor for advancing said member along a generally horizontal path to a punching station, a punch press located in said punching station and supported for vertical bodily movement relative to said member, means for causing said press to advance vertically in one direction from a home position and for stopping said press when the latter reaches a preselected punching position relative to said member, a rotary control element, a reversible rotary motor connected to rotate said control element, means for causing said motor to advance said control element in one direction from a starting position when said press advances from said home position and to stop said element when said press stops in said punching position, a switching device associated with said control element and adapted to be switched from a first state to a second state as said element leaves said starting position, means for causing actuation of said press when the latter is in said punching position thereby to effect punching of a hole in said member, means for thereafter causing said press to return reversely toward said home position and simultaneously causing said motor to return said control element toward said starting position, said press and said control element returning at substantially the same velocities as undertaken by the press and the element, respectively, during their advance, said control element causing said switching device to switch from said secOnd state to said first state when said element returns to said starting position, and means responsive to said switching device and operable to stop the return of said press and said control element when said switching device switches to said first state.