US3704611A - Gauging system for press brakes - Google Patents

Abstract

Gauges for press brakes and a control system having a plurality of adjustable gauge arms, each of which is pneumatically controlled for movement into effective and non-effective positions automatically upon selected sequential operation of the press.

Description

' [22] Filed:

United States Patent Hirsch 1 1 GAUGING SYSTEM FOR PRESS BRAKES [72] Inventor: Roger B. Hirsch, 2034 W. Fulton St., Chicago, 111. 60612 March 5, 1970 [21] Appl. No.: 16,669

[451 Dec. 5, 1972 2,782,831 2/1957 Todd, Jr. ..72/461 2,627,890 2/1953 Lloyd et a1 ..72/461 2,924,260 2/1960 Guarino ..72/36 3,465,561 9/1969 l-lanni ..72/36 2,669,276 2/1954 Humphrey ..72/455 3,580,023 5/1971 Merrill et al ..72/461 Primary Examiner-Lowell A. Larson Attorney-Martin Faier [5 7] ABSTRACT Gauges for press brakes and a control system having a plurality of adjustable gauge arms, each of which is pneumatically controlled for movement into effective and non-effective positions automatically upon selected sequential operation of the press.

25 Claims, 10 Drawing Figures GAUGING SYSTEM FOR PRESS BRAKES The invention relates to a control system for the gauge arms on a press brake, which are designed forautomatic or selective positioning into effective and noneffective positions. In the use of a press brake, it is frequently desired to perform a plurality of bends in a sheet of material. l-Ieretofore, it has been necessary to manually locate or adjust the gauges for repeat operations to obtain a plurality of bends in a single sheet or several sheets. i

In the present disclosure, there is taught a plurality of sets of gauges designed to be automatically set in effective or non-effective positions. Each gauge has associated with it a pneumatically actuated pistoncylinder assembly, each or some of which may be selectively actuated in a programmed fashion to carry an associated gauge arm out of and into effective position. More specifically, the press brake may be provided with a plurality of sets of three each of gauges, one set of which is connected through its own manifold to a .source of pneumatic pressure, another set of which is also connected through another manifold with a source of pneumatic pressure, and the third set of which is not connected to said source.

These sets of gauges are arranged longitudinally to the rear of the anvil die of the press brake, and, because three or more sets of the gauges may be provided at each station of the press brake, the operator or operators can progressively advance a sheet of material from one set of gauges to the other in a predetermined programmed fashion for obtaining a plurality of bends in the sheet, i.e., one bend at each station during each stroke of the press, without manual adjustment of the gauges. The operation of the pneumatic cylinders is electrically controlled automatically in a step by step operation, or at the option of the operator in a non-automatically sequenced mode, as hereinafter more specifically described.

It 'is an objectof this invention to provide a press brake with novelly constructed gauge assemblies.

Another object is to provide "gauges of novel construction.

Another object is to provide novel means'for moving the gauge arms selectively into effective and non-effective positions.

Another object is to provide novel electrical means for controlling the positions of the gauges automatically.

Another object is to provide control means, automatic in its operation for facilitating sequential production of multiple bends in sheet material or other related sequential press operations.

Another object is to provide an assemblage of the character referred to which is not difficult to manufacture or install and that may selectively be operated in a manual or automatic mode and is very efiicient in use.

Another object is to provide a novel method for setting and actuating press brake gauges.

Other objects and advantages of the invention will become apparent with reference to the following description and accompanying drawings.

In the drawings:

FIG. 1 is a front elevational view of a press brake embodying the features of the invention.

FIG. 2 is a rear elevational view thereof.

FIG. 3 is a fragmentary plan view of the back bar showing the novel gauges thereon.

FIG. 4 is a vertical sectional view of the back bar showing a gauge in operable position in side elevation, and in inoperable position in dotted lines.

FIG. Sis a sectional view of a modified form of back bar incorporating manifolds for the air lines.

FIG. 6 is a top plan view of a close finger accessory.

FIG. 7 is a top plan view of a modified close finger accessory.

FIGS. 8 and 8A are schematic views of the electrical circuitry for the gauge control system.

FIG. 9 is a view of the control panel.

Referring to the exemplary disclosure of the invention shown in the accompanying drawings, and particularly to FIGS. 1 and 2, thepress brake 11 includes a lower die or anvil l2, and an upper vertically reciprocable punch or die 13. These two dies extend parallel to one another the width of the press brake and are located on the front side thereof. In operation, a sheet of material, such as sheet steel, is laid on the lower die or anvil 12 with its leading edge extending into the press brake a distance determined by the ultimate location of a bend to be produced therein when the upper die is carried downwardly into tight engagement with the lower die. The upper die 13 is periodically reciprocated under manual control, or under automatic control by means ,of electrical components to be described presently; and the press brake may be actuated by hydraulic, hydra-mechanical or mechanical means.

The distance to which the sheet is inserted over the anvil die 13 is determined by the setting of one or more gauges, generally indicated at 14. As best shown in FIGS. 2 through 4, there are a number of gauges 14 mounted for longitudinal adjustment along a back 'bar 15 that bridges the press brake rearwardly of the mating dies 12 and 13. These gauges are all alike and the following language describing one of them applies to all the gauges. Depending upon the width of the sheet material to be bent, gauges 14 may be provided in sets of one or more, with a sufficient number provided in each set to allow the operator to insert the material from the front of the machine over the lower die 13 against the gauges in a firm fashion so that the material is exactly aligned with the position of the intended bend.

Each gauge 14 includes a yoke 16 that is longitudinally slotted and adjustable to secure the gauge to the back bar 15, as by clamp bolt 17. The yoke is longitudinally channelled on its upper face and at its front end, as at 18, to receive seated in said channel a flop arm 19 that is pivoted at its rear, as at 21, to the yoke 16, so as to be swingable in a vertical plane. The free forward end of the flop arm has a bearing enlargement 22 into which is threaded a gauge screw 23. The screw 23 has micrometer markings 24 thereon that register with a marking index edge 25 on the bearing enlargement, and it is locked in place by clamp screw 19a.

When the flop arm 19 is in the full line position shown in FIGS. 3 and 4, the lead edge of sheet 26 inserted between the dies abuts one of said gauge screws 23 to limit its inward movement. Upward displacement of the gauge bar flop arm 19, when abutted by the sheet, is prevented by offsetting the stop face of the flop arm below the pivot point 21. Gauge assembly adjustment is initially accomplished by adjustmentof the yoke on back bar 15, and then adjustment of gauge screw 23 affords precise adjustment as to determine the exact location of the formation of the bend to be developed in the sheet when the dies are brought together. Because it may be and frequently is desired to provide a number of spaced formations in the sheet upon successive operation of the dies, the gauges may be provided in set of three each as shown, and at least two gauges may be provided with means to render them non-effective as hereinafter specifically described.

Each of the gauges 14 of each set are individually adjusted to correspond with the intended location of a formation in the sheet. To this end, as best shown in FIG. 3,- one ofthe gauges 14A is in the down or active position through signal from the electronic system. A second gauge 14B is in an up or inactive position. The third gauge 14C is physically located furthest from the die 12. This gauge 14C is not connected to the manifold to cause the units to remain in the lowered position at all times.'ln operation, one active gauge may be lowered into position to form a particular formation while the second gauge is in the upward position, and the third gauge is in the lowered position. Since the third gauge is furthest back from the die 12, the lead edge of sheet 26 will not contact this gauge unless all active gauges are in the up position. This allows three different bend sizes at any area of the machine.

To accomplish successive movement of flop arms on gauge b'ars 14A and 148 into their non-effective positions, each gauge is provided with cylinder 27 having its piston rod 28 located below the respective flop arm and just forwardly of pivot 21 and in substantial contact therewith. Located on the inside of the press brake is a set of solenoid valves 58-73 (shown in FIG. -2) having a pair of independent leader pipes 31, 32 communicating therewith. One of these pipes, e.g., pipe 31, is connected by flexible conduit 33 to cylinders 27 associated with gauge 148. Other flexible conduits 34 connect pipe 32 with cylinders 27 associated with gauge 14A. Normally, these piston-cylinder assemblies retain the flop arms in the elevated positions shown in dotted lines (FIG. 4), and when pressure in the associated conduit and cylinder is relieved, as to withdraw rod 28 from the associated flop arm 19, the flop arm drops by gravity into its effective position. The cylinder assemblies may be air or hydraulically actuated, or actuated by other means.

In lieu of leader pipes 31, 32, the back bar may be formed as shown in FIG. 5. Here the back bar a is extruded with a pair of conduits 37 connected with cylinder 29, and the plurality of flexible conduits 33a, 34a, lead therefrom to the various cylinders.

In operation so far as described, assuming flop arms of gauge 14A to be down, when the first bend has been made in sheet 26, while the sheet is abutted against said gauge bar 14A, means is actuated automatically or manually to admit air pressure into cylinder 27 of gauge 14A. This causes flop arm on gauge 14A to be raised into substantially vertical position, shown in dotted lines in FIG. 4. Air is exhausted from cylinder 27 of gauge 143 to permit it to fall into effective position. The sheet 26 is then advanced into the dies until its lead edge contacts gauge 148. The press is then cycled to generate the second bend therein. Following making the second bend, air pressure is admitted into cylinder 27 of gauge 14B, whereupon flop arm 19 thereof is elevated (and flop arm on gauge 14A remains elevated). The sheet 26 is again advanced into abutment with gauge 14C which has remained in horizontal position (since the same has no air pressure connection), and the press cycle is repeated. Should the sheet 26 be of considerable length, a plurality of the sets of gauges may be utilized to maintain alignment.

FIG. 6 shows one form of a close finger accessory 41 that is removably and adjustably secured to the flop arm 19 for use when close tolerances and the form and configuration of the flange on the material requires spacing of the bend from the free end 44 of the finger rather than from the screw 23. As shown, the accessory 41 comprises a strap of sheet material, preferably of stainless steel, that has its tail end secured by a stud-nut 42 to the flop arm 19 and has its forward free end bent downwardly, as at 43, and then forwardly, as at 44, on the axial center of the micrometer screw 23, thus formed to permit its end 44 to seat on the rear margin of the die 12.

In the modified close finger accessory shown in FIG. 7, the lower die 12 is slotted, as at 46, to receive the front end or finger 47 of the close finger accessory 48, which is secured as by nut-bolt 49 to the flop arm 19. This accessory affords means for gauging a sheet 26, shown in broken lines, at the cut out corners thereof, to assume close tolerance at the location of the intended bend.

Operation of the press brake preferably is automatic, so that it mayfunction in repeat cycles without manual adjustment or positioning of the gauges. Means is also provided to manually displace the flop arms, and such manual displacement, as well as automatic operation, is best controlled electrically such as by useof the circuitry disclosed in FIGS. 8 and 8A.

As shown in FIG. 8A, current is supplied from. a service line through leads-5 1 and 52 which terminate at terminals 53 and 54 in a socket-plug assembly 55.

For manual operation, a manual-automatic switch 76 (see (FIG. 8) is moved downwardly into manual position to open switch element 760 and also open automatic switch element 77. Now, to energize solenoids 58 to close main line 32 so that flop arms 19 connected therewith drop down, control switch 59 (FIG. 8A) in front control box 61 (FIG. 1) is closed momentarily. This energizes the relay coil in latch relay 62 which functions to close lower contacts of switches 63-64 to deliver current through switch 63 to solenoid 58, energizing same and exhausting line 32. The other switch 64 is connected through line 65 to limit switch 66 through plug-socket terminal 67. This limit switch 66 is mounted preferably on the side of the press brake, as shown in FIG. 1, for engagement when the press is operated, although it may be mounted at any convenient location on the brake so that it is mechanically located to be tripped and thus energized during the second half of each stroke of the press; or it may be coupled with a signal relay and incorporated into the circuitry of the press as to be energized during the second half of each stroke of the press. When the press completes one cycle of operation, switch 66 opens momentarily to cut off power to relay 62.

To engage manually another set of gauges, i.e., those connected to fluid line 31, control switch 68 in front control box 61 is closed momentarily, to energize relay coil 69, which functions to close lower contacts of switches 71-72 to deliver current through switch 72 to solenoid 73, thus energizing same and exhausting line 31. The other switch 71 is connected by line 74, through plug-socket terminal 75, to limit switch 66, which operates to cut off current to relay 69 after one operating cycle. In this manner the system can be manually operated during successive cycles of press operation. These manual cycles can be effected even though the press has been operating under automatic conditions,'which will now be described.

For automatic operation, the automatic-manual switch 76-77 is in the position shown, that is with the middle and upper switch blades of each in contact with the other, and power delivered to a stepper switch 78 through line 79. A pulse switch 81 is connected to a pilot light 82 through switch 76 and pulse switch 83 in line 84. At the same time current flows through a reset switch 85 to a start indicator lamp 86.

Current is delivered to the stepper sweep arm 78a through line 87. At the start, thearm 78a is in engagement with tap which is connected by line 88 to the center terminal 89a, ofthe first of a series (four shown, but any number can be incorporated into the system) of switches 89. All solenoid valves are in open position at this time so that all of the controlled gauge flop arms plugged into both conduits are in their up substantially vertical positions. This series of switches 89 (preferably fifteen in the embodiment illustrated) are mounted in a control panel 91 (see FIG. 9) which has a series of control buttons 92, one for each switch. The center blade 89a of switch 89 is moved down into contact with the lower blade 89b to complete a circuit from tap 0 through the switch, line 93, tap 75 in the plugsocket 55, from where a lead 94 goes to the fluid line solenoid 73 to energize the same and cause the connected gauges flop arms 19 to drop. Current also flows through a line 95 to the relay switch 63 which is in neutral position. When the center blade 89a of switch 89 is moved up into contact with the upper blade 890, the current flows through a line 96 to tap 97 in the plug-socket 55, then through line 98, terminal 99, to relay 62. It also flows from tap 97 through line 101 to solenoid 58 to cause the flop arms 19 of the connected gauges to drop into operative positions.

In use, a sheet 26 of material is inserted into the press brake, as aforesaid, and the press cycles to form the sheet. At it cycles up, the limit switch 66 is actuated to cause current to flow through line 102, switch 76 and lines 103 and 104 from terminal 92 in the plug-socket assembly 55 to pulse coil 81. This advances the sweep arm 78a to the l tap which is connected by line 105 to the center blade 106 of the second switch 89. Each time the press is cycled, the sweep arm 76a advances to taps 2, 3, 4, etc., successively, until the last effective switch determined by the setting of the selector switch 107 is actuated. Specifically, in this illustrative disclosure, the selector switch is set at 3, which means three bends are to be performed. This switch has its taps l 2, 3 connected to taps l, 2", 3, respectively, of the stepper switch. Thus, after the third bend is made (i.e., tap 2), the stepper switch is advanced to tap 3 by limit switch 66, and current flows to the selector sweep switch arm 108, leads 109 and 110, to the reset coil 111, which closes the conventional reset mechanism (not shown) to allow the sweep arm 78a to return to 0. The pulse switch 83 allows for the stepper operation without breaking the circuit to the latch relays 62-69.

A reset switch 112 is connected in parallel with a reset switch 113 in the front control box 61, both of which are connected through lead 114 leading to the reset coil 111; thus at any time during cycling, the system can be returned to zero upon actuation of either switch 112 or 113.

If desired, a' units and stroke counter can be incorporated into the system. The counter is shown at 115 and it has one of its lead connected to neutral and the other lead to the center blade of unit-cycle switch 116, the upper blade (i.e., unit counter position) of which is connected to the reset switch 112, and its lower blade i.e., stroke counter position) is connected through a lead 117 with line 84, leading to switch 76, through which it receives current from limit switch 66. When the counter switch is in unit" position, each time the number of bends set into the system by the selector has been reachedand the stepper switch returned to zero, the counter receives a signal and records one unit having the number of bends set into the system by the selector. When the counter switch'is in its upper or cycle position, each time the press brake cycles in an up-stroke and the limit switch is actuated, the counter receives a signal and records one stroke indicating one bend has been made. If one desires to count both units and cycles at the same time, another counter circuit like the one shown can be added to the system parallel to the counter described.

It should be evident thatwhen required additional banks of stepper switches 78 and'related switches 89 can be added to the system to control additional and other functions of the machine. Such add-on features can be used to program sequential control for tonnage, depth control, ram position and the like where structure is provided in the machine into which the system is incorporated to permit those functions.

While I have described and illustrated a preferred embodiment of my invention, it should be understood that changes and modifications in the various details disclosed can be made without departing from the spirit of the invention, and nothing herein shall be construed as limitations upon the invention, its concept or structural embodiment as to the whole or any part thereof, except as defined in the appended claims.

I claim:

1. Gauge control means for a press brake having upper and lower dies comprising, in combination, a plurality of gauges, a flop arm on each gauge, means operable to move the flop arms into ineffective posi tions, and means to actuate said flop arm moving means.

2. The control means recited in claim 1, in which the gauges are adjustable to carry the flop arms toward and away from the dies, and a gauge adjustment member is carried on each flop arm.

3. The control means recited in claim 2, in which the gauge adjustment member is a screw bearing microrneter markings.

4. The control means recited in claim 1, in which an accessory finger gauge is carried on the flop arm.

5. The control means recited in claim 1, in which the means for actuating the flop arm moving means comprises an electrical system including a selector switch and a stepper switch.

6. The control means recited in claim 5, in which the electrical system can function under manual and automatic control. 7. The control means recited in claim 1, in which the gauges are arranged in sets and the means operable to move the flop arms into ineffective positions is selectively operable to cause movement of the flop arms in selected sets.

8. The control means recited in claim 1, in which the means for actuating said flop arm moving means includes fluid operated means.

9. The control means recited in claim 8, in which the fluid operated means includes piston-cylinder assemblies one associated with each flop arm.

10. The control means recited in claim 1, in which manual control means for the moving of selected flop arms into ineffective positions is mounted on the front side of the press brake.

1 1. A gauge fora press brake comprising, in combination, a back bar, an elongated body mounted on the back bar, a flop arm pivotally mounted at oneend to said body, and an adjustable gauge element on the other end of said flop arm, said gauge element being offset from the plane of the flop arm pivot point.

12. The gauge recited in claim 11, in which the flop arm and adjustable gauge element carry complemental index markings.

13. The gauge recited in claim 11, in which the adjustable gauge element comprises a screw carrying micro-index markings.

. 14. The gauge recited in claim 13, in which means is provided to lock the screw adjustment.

15. A gauge for a press brake comprising, in combination, a back bar, an elongated body mounted on the back bar, a flop arm pivotally mounted at one end to said body, a gauge element on the other end of said flop arm, and an auxiliary gauge detachably secured to the flop arm.

16. The gauge recited in claim 15, in which the auxiliary gauge extends forwardly of the adjustable gauge element.

17. The gauge recited in claim 15, in which the auxiliary gauge has its free forward end disposed in a vertical plane.

18. An electric control system adaptable for regulating movement of gauge flop arms from effectiveto ineffective positions comprising, in combination, a line circuit including a .series of manually set switches, a stepper switch, a selectorswitch and mechanismcontrol solenoids, impulse means in the circuit to actuate the stepper switch step by step so as to deliver current through selected manual switches to selected solenoids.

19. The control system recited in claim 18, wherein the control solenoids function to operate valves in a fluid system connected to the flop arms.

20. The control system recited in claim 18, wherein the solenoids can be selectively actuated independently of said ste er switch.

21. The ontrol system recited in claim 18, in which the circuit includes switch means operable to permit manual and automatic control of the means for actuating the gauge flop arms. g

22. Gauge controlmeans for a press brake comprising, in combination, a plurality of gauges, a flop arm pivotally mounted at one end of each gauge for movement in a vertical plane,a stop face on the free end of said flop arm, said face being below the pivotal mounting, means operable to move the flop arm into an ineffective elevated position,and means to actuate the flop arm moving means.

23. The method of gauging the size of successive bends to be formed in a sheet of material by a press brake having gauges, each gauge comprising a body and a movable flop arm connected to said'body and having mechanical means operable to move said flop arms and electrical means to actuate the operable means, comprising the steps of setting a plurality of gauges in line with a sheet of material to be formed, positioning said gauges to define the size of each successive formation, bringing the sheet of material into contact with the first gauge to make a first formation, actuating the electrical and mechanical means to move the flop arm of the first gauge into ineffective position, bringing the sheet of material into contact with each next successive effective gauge to make each respective formation, and actuating the electrical and mechanical means to move the flop arm of each preceding gauge into ineffective position before each successive formation is effected.

24. The method recited in claim 23, with the added step of controlling actuation of the electrical means by switch means actuable by the cycling of the press brake.

25. The method recited in claim 23, with the added step of selectively electing which of the operable means is actuated.

Claims (25)

1. Gauge control means for a press brake having upper and lower dies comprising, in combination, a plurality of gauges, a flop arm on each gauge, means operable to move the flop arms into ineffective positions, and means to actuate said flop arm moving means.

2. The control means recited in claim 1, in which the gauges are adjustable to carry the flop arms toward and away from the dies, and a gauge adjustment member is carried on each flop arm.

3. The control means recited in claim 2, in which the gauge adjustment member is a screw bearing micrometer markings.

4. The control means recited in claim 1, in which an accessory finger gauge is carried on the flop arm.

5. The control means recited in claim 1, in which the means for actuating the flop arm moving means comprises an electrical system including a selector switch and a stepper switch.

6. The control means recited in claim 5, in which the electrical system can function under manual and automatic control.

7. The control means recited in claim 1, in which the gauges are arranged in sets and the means operable to move the flop arms into ineffective positions is selectively operable to cause movement of the flop arms in selected sets.

8. The control means recited in claim 1, in which the means for actuating said flop arm moving means includes fluid operated means.

9. The control means recited in claim 8, in which the fluid operated means includes piston-cylinder assemblies one associated with each flop arm.

10. The control means recited in claim 1, in which manual control means for the moving of selected flop arms into ineffective positions is mounted on the front side of the press brake.

11. A gauge for a press brake comprising, in combination, a back bar, an elongated body mounted on the back bar, a flop arm pivotally mounted at one end to said body, and an adjustable gauge element on the other end of said flop arm, said gauge element being offset from the plane of the flop arm pivot point.

12. The gauge recited in claim 11, in which the flop arm and adjustable gauge element carry complemental index markings.

13. The gauge recited in claim 11, in which the adjustable gauge element comprises a screw carrying micro-index markings.

14. The gauge recited in claim 13, in which means is provided to lock the screw adjustment.

15. A gauge for a press brake comprising, in combination, a back bar, an elongated body mounted on the back bar, a flop arm pivotally mounted at one end to said body, a gauge element on the other end of said flop arm, and an auxiliary gauge detachably secured to the flop arm.

16. The gauge recited in claim 15, in which the auxiliary gauge extends forwardly of the adjustable gauge element.

17. The gauge recited in claim 15, in which the auxiliary gauge has its free forward end disposed in a vertical plane.

18. An electric control system adaptable for regulating movement of gauge flop arms from effective to ineffective positions comprising, in combination, a line circuit including a series of manually set switches, a stepper switch, a selector switch and mechanism control solenoids, impulse means in the circuit to actuate the stepper switch step by step so as to deliver current through selected manual switches to selected solenoids.

19. The control sysTem recited in claim 18, wherein the control solenoids function to operate valves in a fluid system connected to the flop arms.

20. The control system recited in claim 18, wherein the solenoids can be selectively actuated independently of said stepper switch.

21. The control system recited in claim 18, in which the circuit includes switch means operable to permit manual and automatic control of the means for actuating the gauge flop arms.

22. Gauge control means for a press brake comprising, in combination, a plurality of gauges, a flop arm pivotally mounted at one end of each gauge for movement in a vertical plane, a stop face on the free end of said flop arm, said face being below the pivotal mounting, means operable to move the flop arm into an ineffective elevated position, and means to actuate the flop arm moving means.

23. The method of gauging the size of successive bends to be formed in a sheet of material by a press brake having gauges, each gauge comprising a body and a movable flop arm connected to said body and having mechanical means operable to move said flop arms and electrical means to actuate the operable means, comprising the steps of setting a plurality of gauges in line with a sheet of material to be formed, positioning said gauges to define the size of each successive formation, bringing the sheet of material into contact with the first gauge to make a first formation, actuating the electrical and mechanical means to move the flop arm of the first gauge into ineffective position, bringing the sheet of material into contact with each next successive effective gauge to make each respective formation, and actuating the electrical and mechanical means to move the flop arm of each preceding gauge into ineffective position before each successive formation is effected.

24. The method recited in claim 23, with the added step of controlling actuation of the electrical means by switch means actuable by the cycling of the press brake.

25. The method recited in claim 23, with the added step of selectively electing which of the operable means is actuated.

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