US3733885A

US3733885A - Automatic press brake back gauge

Info

Publication number: US3733885A
Application number: US00138459A
Authority: US
Inventors: E Brauer
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-19
Filing date: 1971-04-19
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22

Abstract

A back gauge for a press brake having a stop assembly controlled by an indexing roller. The stop assembly is positioned adjacent a press brake die and punch by a pneumatic cylinder actuated in response to the position of the press brake ram. The indexing roller controls the positioning of the stop member at preselected distances from the press brake die to control the position of a work piece on the press brake die.

Description

waited States Patent [191 Braden [54] AUTOMATIC PRESS BRAKE BACK GAUGE [76] Inventor: Edwin Henry Brauer, 3876 Silsby,

Cleveland, Ohio 44111 22 Filed: Apr. 19, 1971 21 Appl.No.:138,459

[52] U.S. C1 ..72/461, 72/389 [51] Int. Cl. ..B2ld 111/22 [58] Field of Search ..72/461, 36, 380, 72/385, 386, 389

[56] References Cited UNITED STATES PATENTS 2,782,831 2/1957 Todd ..72/461 784,726 3/1905 Yates ..72/461 11] 3,733,885 51 May 22, 1973 2,627,890 3/1953 Lloyd ..72/461 3,421,359 1/1969 Gibbs ..72/461 3,592,033 7/1971 Murdoch ..72/36 2,618,349 11/1971 Roch ..72/36 Primary Examiner-Charles W. Lanham Assistant ExaminerGene P. Crosby Att0rneyAlan N. McCartney [57] ABSTRACT A back gauge for a press brake having a stop assembly controlled by an indexing roller. The stop assembly is positioned adjacent a press brake die and punch by a pneumatic cylinder actuated in response to the position of the press brake ram. The indexing roller controls the positioning of the stop member at preselected distances from the press brake die to control the position of a work piece on the press brake die.

27 Claims, 21 Drawing Figures PATENT 122 1915 SHEET 1 OF 4 INVENTOR EDWIN H. BRAUER 4 2 M (Mir n7 ATTORNEYS PAIENTEL mzz I973 733 5 SHEET 3 BF 4 ED H. BRAUER Loafing ATTURNFYS PATENIE mzz 1973 SHEET 0F 4 FIGZO INVENTGR EDWIN H. BRAUER ATTORNEYS NATURE AND OBJECTS OF THE INVENTION It is an object of this invention to provide a back gauge for a press brake which will automatically position a stop member with respect to the press brake to control the position of the work piece with respect to the die.

It is a further object of this invention to provide a back gauge for a press brake having a stop member actuated by a pneumatic cylinder and positioned with respect to the press brake die to control the distance a work piece is inserted over the die.

It is a still further object of this invention to provide a back gauge for a press brake having a stop member for positioning a work piece on the press brake die wherein the back gauge is transversely and laterally adjustable with respect to the press brake.

It is another object of this invention to provide a back gauge for a press brake having an indexing roller controlling the position of a stop member against which a work piece is placed wherein the indexing roller automatically positions the stop member with respect to the press brake die upon the rise and fall of the ram of the press brake.

It is another object of this invention to provide a back gauge for a press brake having a stop member for positioning a work piece with respect to the press brake die, the back gauge having an indexing roller automatically indexed by a stop member on each stroke of the ram of the press brake to position the stop member with respect to the press brake die.

BACKGROUND OF INVENTION In the past, in the use of press brakes for forming articles, a manually positioned stop member has been used to limit the distance at which a work piece is inserted over a press brake die. In practice in forming articles having multiple bends, the work pieces resulting in the desired articles would be formed as follows. The press brake back gauge would be manually positioned to form one of the bends in a work piece and each work piece individually would then be placed in the press brake die to form that particular bend. Then, the back gauge would be manually repositioned to form the next bend and each work piece would be again separately formed by the press brake. This procedure of forming separate bends in each work piece required each work piece to be handled a multiplicity of times during the forming operation.

To eliminate these multiple handling problems during a press brake forming operation, it was determined that it would be desirable to perform all forming operations on a given work piece before commencing any forming operations on the next work piece. In essence, performing all forming operations on a given work piece to form the desired resulting article before performing any additional forming operations on the next work piece was desirable to eliminate multiple handling of each work piece. This required the development of a back gauge which would automatically position a stop member with respect to the press brake die a multiplicity of distances from the die so that each work piece could be inserted a variety of distances into the die in order that a plurality of forming operations on a single work piece in sequence could be performed. Further, it was determined that such a stop member should be sequentially positioned in response to the rise and fall of the press brake ram to be repositioned during each forming operation. It is an automatically positioned back gauge of this type that forms the new and novel invention of this disclosure.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a top plan view of the back gauge of this invention attached to a press brake.

FIG. 2 is a side sectional view of the press brake taken along lines 2-2 of FIG. 1.

FIG. 3 is a fragmentary side elevational view of the press brake back gauge of this invention.

FIG. 4 is a side sectional view of the press brake taken along lines 4-4 of FIG. 1.

FIG. 5 is an enlarged sectional view taken along lines 5-5 of FIG. 4.

FIG. 6 is an enlarged sectional view taken along lines 6-6 of FIG. 4.

FIG. 7 is a projection view of the indexing roller with cam roller in positions of indexing the guide roller.

FIG. 8 is an enlarged fragmentary sectional view taken along lines 8-8 of FIG. 4.

FIG. 9 is a fragmentary view of the indexing roller with skip indexing valve.

FIG. 10 is a sectional view taken along lines 10-10 of FIG. 9.

FIG. 11 is a sectional view taken along lines 11-11 of FIG. 9.

FIG. 12 is an enlarged sectional view taken along lines 12-12 of FIG. 4.

FIG. 13 is an enlarged sectional view taken along lines 13-13 of FIG. 4.

FIG. 14 is an enlarged sectional view taken along lines 14-14 of FIG. 1. 1

FIG. 15 is an enlarged sectional view taken along lines 15-15 of FIG. 1.

FIG. 16 is an enlarged sectional view taken along lines 16-16 of FIG. 1.

FIG. 17 is a sectional view taken along the lines 17-17 of FIG. 16.

FIG. 18 is an enlarged sectional view of a modified adjustable stop button.

FIG. 19 is an enlarged view of an extension of a stop button.

FIG. 20 is an enlarged view of an adjustable stop plug for the indexing roll.

FIG. 21 is a plan view of the cam actuator and valve on the press brake.

DESCRIPTION OF INVENTION The automatic back gauge of this invention can be utilized with any conventional press brake or similar type forming apparatus, one of which is diagrammatically illustrated in the drawing. The press brake 1 comprises a press brake bed 2, a bolster 2, a die 2", a punch 3 and ram 3'. In normal operation, through the rise and fall of the ram 3' with punch 3 against die 2", a predetermined given configuration of bend can be placed in a work piece 4 which is held over the die 2" of the press brake. The back gauge assembly 5 of this invention has a stop member assembly 6 which can be positioned a variety of different distances from the die 2" and, thus, the press brake to limit the distance of insertion of work piece 4 over the die (see FIG. 3) to place the work piece at a desired location for forming,

for example, a bend as illustrated in FIG. 4, in the work piece.

The back gauge assembly 5 comprises support brackets 7 which mount the entire assembly on the press brake bed 2. The support brackets 7 comprise rails 8 laterally spaced on bed 2 and fixed to the bed on their upper and lower ends (not shown) by threaded sockets 9 welded at 10 to the back side 11 of the bed 2. The rails 8 are provided with openings 12 in their upper and lower ends, through which lock bolts 13 pass and which are threaded into the sockets 9 to hold rails 8 securely on the bed 2. Also, the bolts 13 are provided with washers 14 and lock washers 15 to securely affix the rails 8 with respect to the bed 2.

Extending upwardly from the bottom or lower ends (not shown) of each rail 8 is an angle rail 16. Attached to the

upper ends

17 and 18 of the

rails

8 and 16 respectively, are

main support beams

19 and 20. The

beams

19 and 20 are attached to

rails

8 and 16 respectively, as by weldments 21.

Beams

19 and 20 extend transversely away from the back edge 11 of bed 2 and are laterally spaced with respect to the bed as illustrated in FIG. 1.

The

beams

19 and 20 are identical in cross-section and are illustrated in enlarged detail in FIGS. 16 and 17. Each

beam

19 and 20 have T-shaped troughs 22 having an enlarged portion 23 and a throat portion 24. Each of the troughs 22 receive two lock nuts 25 each having a head 26 seated in the enlarged portion 23 and a neck 27 carried in the throat portion 24 of the troughs 22. The troughs 22 of the

beams

19 and 20 serve to provide an adjustable support for

cross beams

28 and 29 to transversely position the

cross beams

28 and 29 with respect to the die 2".

The

cross beams

28 and 29 are each carried on the upper edge 30 of each of the

main support beams

19 and 20.. The cross beams 28 and 29 (see FIGS. 16 and 17) also each contain troughs shown at 31, which are identical in the cross-section. The troughs 31 each comprise an enlarged portion 32 and a throat portion 33. Adjacent each end 34 of the cross beams 28 and 29 are openings 35 for receipt of lock bolts 36. The bolts 36 have heads 37 seated on shoulders 38 in openings 35 and a shank portion 39 threaded into threaded openings 40 in iocknuts 25. Each of the bolts 36 contain a hex or slotted opening (not shown) in heads 37 for tightening heads 37 of bolts 35 against shoulders 38 of openings 35 and securing heads 26 of the lock nuts 25 in enlarged portions 23 of troughs 22 of the main support beams 19 and 20. To position cross beams 28 and 29 with respect to die 2", the machine operator merely inserts a tool into the head 37 of each bolt 36 to loosen lock nuts 25. Thereafter, the cross beams 28 and 29 can be each positioned on the main support beams 19 and 20 and thus appropriately spaced from the die 2". Thereafter, the operator merely retightens the bolts 36 to securely position the cross beams 28 and 29 on the main support beams 19 and 20.

The troughs 31 each carry at least two lock nuts 41 having heads 42 and necks 43. The heads 42 are seated in enlarged portions 32 of troughs 31 and the necks 43 of lock nuts 41 are carried in throat portions 33 of the troughs 31. The arrangement of lock nuts 41 in troughs 31 permit lateral adjustment of a main support plate 44 of the back gauge assembly 5, as will become apparent hereinafter.

The main support plate 44 extends between the cross beams 28 and 29 and is carried on the upper surface 45 of each of the cross beams. Adjacent the ends 46 of the support plate 44, where the support plate overlaps beams 28 and 29, are provided openings 47 in the support plate. The openings 47 receive threaded lock bolts 48 which are threaded into lock nuts 41. The bolts 48 have head portions 49 retained on the support plate 44.

The support plate 44 can be laterally positioned on the

rails

28 and 29 by loosening bolts 48 and sliding lock nuts 41 in troughs 31 to laterally locate the support plate with respect to the die 2". Also, the support plate can be transversely positioned with respect to the die 2" through the previously described adjustable positioning of cross beams 28 and 29 on main support beams 19 and 20. Since the operable or operating portions of the back gauge assembly 5 are carried on the main support plate 44, the operating portions of the back gauge assembly 5 can be both laterally and transversely positioned with respect to the die 2" of the press brake.

The inner end 50 of support plate 44 carries posts 51 secured to the upper surface 52 of the support plate by weldments 53. The outer end 54 of the support plate 44 carries a post plate 55 secured to the upper surface 52 of the support plate by weldments 56. The posts 51 each have openings 57 and the post plate 55 has two openings 58 (see FIG. 14) each of which are aligned with one of the openings 57 on posts 51. The

openings

57 and 58 each receive guide rails 59 which are securely locked into the

openings

57 and 58 by lock screws 60 (see FIG. 14) carried on post plate 55. The guide rails are positioned above support plate 44 and extend away from the back side of the die 2".

Carried on the guide rails 59 is a guide plate 61 which has elongated openings 62 receiving each of the guide rails 59. The openings 62 are larger than the diameter of rails 59 so that the plate 61 is freely slidable on the rails 59.

The guide plate 61 is positioned on the guide rails 59 by means of a pneumatic cylinder 63. The cylinder 63 comprises the conventional chamber 64 with a cap plate 65 for receipt of power in bleed lines (not shown). The cylinder 63 is supported on post plate 55. The inner end cap plate 66 of cylinder 63 carries a plate 67 which is secured to post plate 55 by means of lock bolts 68.

The cylinder rod 69 of cylinder 63 extends through an opening 70 in post plate 55 (see FIG. 14). The opening 70 is larger than the diameter of rod 69 permitting the rod 69 to freely pass through the post plate 55. The end 71 of cylinder rod 69 is received in an opening 72 in the rear face 73 of the guide plate 61. A lock screw 74 retains the end 71 of rod 69 in the opening 72. With this arrangement, it can be seen that actuation of the cylinder 63 through the connection of cylinder rod 69 with guide plate 61, will cause the guide plate to move toward or away from the die 2" on guide rails 59.

The guide plate 61 on its upper face 75 carries an upwardly extending support plate 76. The support plate 76 is secured to the guide plate 61 by means of bolts 77 which pass through openings 78 in the guide plate and are threaded into threaded openings 79 on the under surface 80 of support plate 76 (see FIG. 15). This par ticular type of connection of the guide plate to the support plate 76 permits removal of the support plate from the guide plate to insert different types of support plates.

The support plate 76 has a plurality of

elongated openings

81 and 82 each of which receive an adjustable stop button 83. The stop buttons 83 comprise a bolt 84 having a head 85 and a threaded end 86. The buttons 83 pass through openings 81 in plate 76 with the head 85 of the button 83 being spaced from the plate 76 by sleeves 87 positioned between the head 85 and a washer 88 on the plate 76. The bolt 84 carries another washer 89 on the rear side of plate 76 and a lock nut 90 threaded on the bolt 84 to retain the entire stop button assembly on plate 76 in the

openings

81 and 82 on the plate.

The function of the stop button assembly is to be positioned by means of the pneumatic cylinder and guide plate connection adjacent the die of the press brake to limit the distance of insertion of the work piece 4 over the die 2" at the time the punch 3 places the desired bend in the work piece (see FIG. 3). Also, the mounting of the stop button assembly on the support plate 76 through the

slot connections

81 and 82 permits the button assembly to be located a variety of vertical distances from the surface of die 2" for varyingishapes and configurations of work pieces formed by the press brake.

The back gauge assembly of this invention also provides a means for automatically controlling the length of stroke of the guide plate thus positioning of the stop button assembly with respect to the die varying the distance of insertion of the work piece over the die.

The underside 91 of the support plate 44 carries

brackets

92 and 93. The

brackets

92 and 93 are carried on the inner end 50 and outer end 54, respectively, of the support plate 44 by weldments 94. The

brackets

92 and 93 each contain an opening 95 for receipt of bearing

pins

96 and 97. The

pins

96 and 97 each have heads 98 with radial locking grooves 99 cooperating with lock clips 100 carried on the brackets 91 and 92 by bolts 101. The lock clips 100 contain legs 102 which seat in the lock grooves 99 to retain the

pins

96 and 97 in the

brackets

92 and 93. Removal of the bolts 101 from

brackets

92 and 93 will also permit removal of the bearing pins 96 and 97 from the brackets to remove the indexing roller 103 carried by the

pins

96 and 97 from the brackets for reasons that will become apparent hereinafter.

The bearing pins 96 and 97 carry the indexing roller 103 by means of a centrally located opening 104 extending from end to end of the roller 103. The opening 104 at each end of the roller is enlarged for receipt of a bearing cup 105 into which the bearing pins 96 and 97 are received. This arrangement of the indexing roller 103 being mounted on the bearing pins 96 and 97 through bearing cups 105 permits the roller to freely rotate on the bearing pins.

Positioned between the inner end 106 of the indexing roller 103 and the bracket 92 is a shock absorbing assembly 107 (illustrated in FIGS. 4, 12 and 13). The shock absorbing assembly comprises a plate 108 retained on pin 96 by an opening 109 in the plate. The plate 108 has a flange portion 110 about opening 109 which rests against flange 111 of bearing cup 105. The plate 108 carries a shock plug 112 which has an opening 112 through which pin 96 passes. The shock plug 112 is carried on plate 108 by means of screws 113 threaded into openings 114 in the plug 112.

The shock plug 112 contains a plurality of recesses 115 into which springs 116 are received. As illustrated in FIG. 4, the springs are retained in recesses 115 by plate 108. The recesses 115 have openings 117 in their opposite face through which shock pins 118 pass. The pins 118 have head portions 119 against which the springs 116 are retained. The pins 118 also have end portions 120 which bear against the bracket 92 which forms a reaction point for the springs 116 as will become apparent.

Attention is now directed to FIGS. 4, 5, 6 and 7 wherein the details of the indexing roller 103 are illustrated. The outer surface 121 of the roller 103 contains a plurality of troughs or grooves 122,123,124,125,126,127,128 and 129. Each of the grooves 122 to 129 contain an enlarged inner portion 130 and a reduced throat portion 131. The grooves 122 to 129 extend from the inner end of 106 of the roller 103 and terminate at 132 at an angular radial recess 133 adjacent the outer end of the roller. Each of the throat portions 131 of the grooves 122 to 129 are cut back at the recess 133 to provide a cam surface 134.

Adjacent the recess 133 at the outer end of the roller 103 is provided a radial shoulder 135 having a plurality of cam surfaces 136. The cam surfaces 136 contain an inclined cam face 137 extending from the face 138 of the shoulder 135. The cam face 137 commences from face 138 just above the center line of the grooves 122 to 129 in each instance, as illustrated in FIG. 7. The cam face 137 then extends away from the face 138 toward the outer end of the roller to a point of an arcuate bottom cam surface 139. The radius for the arcuate cam surface 139 is taken on a center line beyond the inner section 140 of cam surface 134 with the point of termination 132 of the grooves 122 to 129 at recesses 133.

Attention is now directed to FIGS. 1 and 2, 4 and 15 which illustrate the cooperation of the guide plate and stop button assembly with the indexing roller 103. The underside 141 of the guide plate 61 carries cam roller support plate 142 (as by weldments 143). The support plate 142 passes from the underside of plate 61 through a slotted opening 144 in main support plate 44 for free back and forth movement with guide plate 61. The lower end 145 of support plate 142 contains a leg 146 which carries a cam roller 147 and an abutment 147'. The cam roller 147 is carried by a bolt 148 and, as illustrated, is positioned by plate 142 into the grooves 122 to 129. The cam roller 147 rides in the throat portion 131 of the grooves 122 to 129.

The indexing roller 103 also includes a stop plug 149 illustrated in FIG. 8. The stop plug 149 is retained in the grooves 122 to 129 at varying locations to limit the travel of the roller 147 in the grooves to position the stop button 83 varying distances from the die 2". The stop plug 149 comprises an abutment bushing 150 retained in the grooves 122 to 129 by a bolt 151. The bolt 151 has a head 152 received in the enlarged portion 130 of each of the grooves 122 to 129. The bolt 151 also has a threaded end 153 on which is received a lock washer 155 and a lock nut 154 to position the bushing in the grooves. The bushing 150 has a shoulder 156 received in the throat 131 of the grooves 122 to 129 and, as illustrated in FIG. 8., is retained therein by the bolt head 152 in the enlarged portion 130 of grooves 122 to 129 and the lock nut 154.

Attentionis now directed to FIG. 21 wherein there is diagrammatically illustrated a valve and cam member which would be carried by the bed of the press brake. The purpose of the valve illustrated at 157 is to actuate the pneumatic cylinder 63. The valve 157 comprises a conventional plunger 158 and roller 1S9 carried on the end 160 of the plunger. The roller cooperates with a cam 161 carried on the bed of the press brake. The cam 161 will rotate in response to the rise and fall of the ram of the press brake to operate the valve 157 to cause operation of the pneumatic cylinder 63. In operation, as will become apparent, the cam 161 causes operation of valve 157 to cause retraction of the cylinder rod 69 when the ram and punch are retracted from the die 2" and upon the ram reaching its upper position causing the cylinder rod to move the guide plate and thus stop button assembly outwardly to its outer most position. At this point, the machine operator can place the work piece over the die of the press brake and up against the stop buttons (see FlG. 3).

In operation, actuation of the pneumatic cylinder 63 through its plunger rod 69 will cause the guide plate to move outwardly on guide rods 69. Through the connec-- tion of support plate 142 with the guide plate 61, the cam roller 147 will ride outwardly in one of the grooves 122 to 129 until the abutment 147' on plate 142 strikes a predetermined positioned stop plug 149. At this point, the machine operator will insert the work piece into the die to abut the stop button 83. Thereafter, the punch will move downwardly and form the appropriate bend in the work piece against the die. Upon withdrawal of the punch from the die, the pneumatic cylinder 63 will be actuated, as previously described, to withdraw plunger 69 causing the guide plate to move away from the die and the roller 147 will be retracted down one of the grooves 122 to 129. As the roller 147 moves downone of the grooves 122 to 129, it will contact the cam face 137 (see FIG. 7). Further withdrawal of the plunger will cause the cam roller 147 to move down the cam surface 137 causing the roller (which is freely rotatable on its support pins 96 and 97) to rotate causing the roller 147 to move further down cam face 137 to a point of seating in the arcuate bottom cam surface 139 of shoulder 135 of the cam roller 103. At this point, the plunger of the cylinder is completely withdrawn and actuation of the cylinder for extension of the plunger will cause the cam to move out of the arcuate bottom cam surface 139 of the shoulder 135 to a point wherein it contacts the cam surface 134 of one of the grooves 122 to 129. Further extension of the cylinder rod will cause the roller to move down the cam surface 134 causing the indexing cylinder to rotate additionally until the roller contacts the next one of the grooves 122 to 129 in sequence. This phase of the indexing of the cam roller is illustrated diagrammatically in the various positions 1 through in FIG. 7. As the piston rod is further extended, the roller will move down the next one in sequence of the grooves 122 to 129 until abutment 147' strikes another of the stop plugs 149. In this fashion, it can be seen that by positioning stop plugs in the grooves 122 to 129 in various locations, as illustrated, at least eight different locations of the stop buttons 83 with respect to the die 2" can be obtained.

It should also be noted that as the support plate abutment 147' contacts a given stop plug 149, there will be considerable force against the end of cylinder 103. The pins 118 of shock absorbing assembly 107 will contact the bracket 92 causing absorbtion of such force through springs 116 of the shock absorbing assembly to prevent damage to the entire apparatus. Further, the provision of release means for removal of the cylinder 103 from

pins

95,96 through lock clips 100 permits the cylinder 103 to be preset with the bushings 150 in the tool room, for example, for the next desired forming operation.

Reference is now made to FIGS. 9 to 11 wherein there is illustrated a means for skip indexing of the indexing roll. That is, in the event, for example, it is desirable to only make three or four bends in a particular work piece (less than eight) then provision must be made to skip index certain of the working grooves 122 to 129 of the index roll. This is accomplished by the provision of a bleed valve 162 which, when operated, will permit the cylinder 63 and its piston rod 69 to move outwardly to permit roller 147 to cooperate with

cams

137 and 134 to index the roller 103 but immediately retract the piston rod to accomplish a double index on a given rise and fall of the ram and punch. This is accomplished by the provision of a conventional valve member 162 being attached, for example, to the bracket 93 by means of bolts 163. The valve would contain an actuating arm 165 attached to the valve 162 to operate the valve when pivoted. The arm 165 could contain a cam roller 166 on the end thereof. On the outer surface 121 of the index roller 103 there is provided apertures radially from the roller 166 into which screws 167 can be threaded. Upon movement of the index roller 103, the roller 166 can contact the heads 167 causing actuation of the valve 162 to cause immediate retraction of the cylinder rod to double index the cylinder.

Attention is now directed to FIGS. 18 and 19 wherein modifications of the stop buttons 83 are illustrated. In FIG. 8 there is illustrated a stop button which would pass through either opening 81 or opening 82 of the support plate 86 and be retained therein by

bolts

170 and 171 on opposite sides of the support plate. The stop button 168 also comprises a threaded portion 172 which receives a sleeve 174 retained thereon and positioned by a lock nut 175. The sleeve 173 has a stop face portion 174. It can be seen that the sleeve 173 can be adjusted on the threaded portion 172 of the button 168 varying distances from the support plate 76 and thus varying distances from the arbor 2.

FIG. 19 illustrates a still further embodiment of the stop button of this invention. In this illustration, a sleeve shown at 176 could be carried by the threaded portion 172 of a stop button of the type 168.. This sleeve is also threaded on the stop button 168 and retained thereon by a lock nut 177. The sleeve 176 carries a right angle feeler gauge 178 retained on the sleeve by a lock screw 179. This again is a still further embodiment of an adjustable stop button arrangement.

Attention is now directed to FIG. 20 wherein there is illustrated a further embodiment of an abutment bushing arrangement. In this bushing arrangement, the bushing 180 is retained in the grooves 122 to 129 by a pair of

lock bolts

181 and 182 which are retained in the grooves in the same manner as lock bolts 151. This bushing arrangement also has an adjustable stop nut 183 which can be positioned in a threaded opening 184 in the bushing and retained therein by a lock screw 185 to give more accurate control to the positioning of cam 147 at its outer most stroke.

Other modes of applying the principle of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed provided the elements set forth in any of the following claims, or the equivalent of such be employed.

I claim:

1. A back gauge mechanism for a press brake having a stop member automatically positioned in response to the rise and fall of the ram and punch of the press brake to provide an abutment against which a work piece placed on the press brake die can be positioned, said back gauge comprising:

a. apparatus carried adjacent the die of the press brake for supporting the back gauge;

b. a guide mechanism carried by said apparatus for movement toward and away from the press brake die;

0. means carried by said apparatus and connected with said guide mechanism actuated in response to the rise and fall of the press brake punch to cause said guide mechanism to perform said movement;

d. a stop member carried on said guide mechanism and positioned by said guide mechanism adjacent the press brake die to form an abutment for a work piece inserted over the die;

e. positioning means carried by said apparatus and coacting with said guide mechanism in response to movement of the guide mechanism to position said guide mechanism and said stop member varying predetermined distances from the press brake die to provide a variable abutment against which the work piece can be positioned.

2. The back gauge mechanism of claim 1 wherein said apparatus comprises main support beams carried adjacent the press brake and extending transversely thereto and cross support beams carried on the main support beams laterally to the press brake die.

3. The back gauge mechanism of claim 2 wherein said connection between the main support beams and cross support beams is adjustable to permit the cross support beams to be positioned toward or away from the press brake die.

4. The back gauge mechanism of claim 1 wherein said apparatus comprises main support beams positioned transversely to the press brake and cross support beams adjustably carried on the main support beams and a main support plate positioned transversely to the press brake die and adjustably carried on the cross support beams for lateral adjustment with respect to the press brake die.

5. The back gauge mechanism of claim 1 wherein said apparatus includes means for adjustably, laterally and transversely positioning said guide means and said positioning means with respect to the press brake die.

6. The back gauge mechanism of claim 1 wherein said means connected with said guide mechanism comprises a pneumatic cylinder having a piston rod connected to said guide mechanism to move said guide mechanism in response to the rise and fall of the press brake ram and punch.

7. The back gauge mechanism of claim 1 wherein said guide mechanism comprises guide rails carried by said apparatus transversely to the press brake die and a guide plate slidable on said guide rails, the stop memher being carried on the guide plate.

8. The back gauge mechanism of claim 7 wherein said means carried by said apparatus includes a pneumatic cylinder having a piston rod connected to said guide plate.

9. The back gauge mechanism of claim 7 wherein the guide plate carries a camming mechanism which actuates said positioning means to limit movement of said guide plate and said stop member toward the press brake die.

10. The back gauge mechanism of claim 1 wherein said positioning means comprises an indexing roller freely rotatably carried on said apparatus and actuated by the movement of said guide mechanism to position the guide mechanism varying distances from the press brake die.

11. The back gauge mechanism of claim 10 wherein said indexing roller comprises an elongated cylindrical member having a plurality of radial grooves extending longitudinally of the roller, and abutment means car ried in said grooves varying distances longitudinally on said roller to coact with said guide mechanism to position said guide mechanism with respect to the press brake die.

12. The back gauge mechanism defined in claim 10 wherein said indexing roller contains cam means and said guide mechanism contains a cam roller cooperating with said cam means to index said roller on each movement of said guide mechanism toward and away from the press brake die.

13. The back gauge mechanism of claim 12 wherein said indexing roller contains longitudinally extending grooves and camming means coacting with said grooves and said guide mechanism contains a cam roller coacting with said grooves and said camming means to index said roller on each movement of said guide mechanism toward and away from said press brake die.

14. In a back gauge assembly for a press brake having a mechanism providing an abutment against which a work piece is placed, an indexing apparatus to control the position of the mechanism with respect to the press brake die comprising:

a. a cylindrical member supported for free rotation and having a plurality of radial longitudinally extending grooves adapted to coact with the abutment mechanism;

b. said grooves terminating adjacent one end of said cylindrical member in a radial recess and providing a first camming surface;

c. and a shoulder on said one end of said cylindrical member providing a second camming surface;

d. said first and said second camming surfaces being adapted to coact with the abutment mechanism to rotate said cylindrical member and position the abutment mechanism with respect to the press brake die.

15. The back gauge assembly of claim 14 wherein the first camming surface comprises a shoulder on the end portion of each of said grooves intersecting said radial recess and said second camming surface comprises recesses in said cylindrical member shoulder radially offset from said first camming surface.

16. The back gauge assembly of claim 15 wherein the second camming surface includes an arcuate bottom cam surface having a radius drawn on a center line beyond the intersection of said first camming surface with said radial recess.

17. A back gauge assembly for a press brake having a punch and die, said back gauge comprising:

a. apparatus for supporting said back gauge adjacent the press brake die;

b. abutment means supported on said apparatus for free movement toward and away from the press brake die;

0. means for moving said abutment means toward and away from the press brake die;

d. control means carried by said apparatus actuated by the abutment means during said movement toward and away from the press brake die;

e. said control means including means limiting the movement of said abutment means toward said die to preselected distances from the die to provide a variably positioned abutment adjacent the press brake die against which a work piece is placed.

18. A back gauge assembly of the type defined in claim 17 wherein said abutment means includes means coacting with said control means to cause actuation of the control means for limiting said movement of said abutment means.

19. A back gauge assembly of the type defined in press brake die.

21. A back gauge assembly of the type defined in claim 20 wherein said mounting of said roller includes a shock absorbing assembly to absorb the longitudinal load on the indexing roller upon said stops limiting movement of said abutment means.

22. A back gauge assembly of the type defined in claim 21 wherein said shock absorbing assembly is carried on said indexing roller mounting and reacts against said apparatus to absorb longitudinally directed loads on said roller.

23. A back gauge assembly of the type defined in claim 17 wherein said abutment means includes guide rails carried on said apparatus transverse to the press brake and a guide plate freely slidable on said guide rails for movement toward and away from the press brake.

24. A back gauge assembly of the type defined in claim 23 wherein the guide plate carries stop buttons against which a work piece is placed.

25. A back gauge assembly of the type defined in claim 24 wherein the stop buttons are vertically adjustable on the guide plate.

26. A back gauge assembly of the type defined in claim 25 wherein the stop buttons are horizontally adjustable on the guide plate.

27. The back gauge mechanism of claim 13 wherein said indexing roller includes valve actuating means and a valve mechanism controlled by said valve actuating mechanism to control said means carried by said apparatus to skip index said indexing roller.

Claims

1. A back gauge mechanism for a press brake having a stop member automatically positioned in response to the rise and fall of the ram and punch of the press brake to provide an abutment against which a work piece placed on the press brake die can be positioned, said back gauge comprising: a. apparatus carried adjacent the die of the press brake for supporting the back gauge; b. a guide mechanism carried by said apparatus for movement toward and away from the press brake die; c. means carried by said apparatus and connected with said guide mechanism actuated in response to the rise and fall of the press brake punch to cause said guide mechanism to perform said movement; d. a stop member carried on said guide mechanism and positioned by said guide mechanism adjacent the press brake die to form an abutment for a work piece inserted over the die; e. positioning means carried by said apparatus and coacting with said guide mechanism in response to movement of the guide mechanism to position said guide mechanism and said stop member varying predetermined distances from the press brake die to provide a variable abutment against which the work piece can be positioned.

7. The back gauge mechanism of claim 1 wherein said guide mechanism comprises guide rails carried by said apparatus transversely to the press brake die and a guide plate slidable on said guide rails, the stop member being carried on the guide plate.

11. The back gauge mechanism of claim 10 wherein said indexing roller comprises an elongated cylindrical member having a plurality of radial grooves extending longitudinally of the roller, and abutment means carried in said grooves vaRying distances longitudinally on said roller to coact with said guide mechanism to position said guide mechanism with respect to the press brake die.

14. In a back gauge assembly for a press brake having a mechanism providing an abutment against which a work piece is placed, an indexing apparatus to control the position of the mechanism with respect to the press brake die comprising: a. a cylindrical member supported for free rotation and having a plurality of radial longitudinally extending grooves adapted to coact with the abutment mechanism; b. said grooves terminating adjacent one end of said cylindrical member in a radial recess and providing a first camming surface; c. and a shoulder on said one end of said cylindrical member providing a second camming surface; d. said first and said second camming surfaces being adapted to coact with the abutment mechanism to rotate said cylindrical member and position the abutment mechanism with respect to the press brake die.

17. A back gauge assembly for a press brake having a punch and die, said back gauge comprising: a. apparatus for supporting said back gauge adjacent the press brake die; b. abutment means supported on said apparatus for free movement toward and away from the press brake die; c. means for moving said abutment means toward and away from the press brake die; d. control means carried by said apparatus actuated by the abutment means during said movement toward and away from the press brake die; e. said control means including means limiting the movement of said abutment means toward said die to preselected distances from the die to provide a variably positioned abutment adjacent the press brake die against which a work piece is placed.

19. A back gauge assembly of the type defined in claim 18 wherein said control means comprises an indexing roller mounted on said apparatus for rotational movement and said roller having radial longitudinally extending grooves coacting with said abutment means during said movement toward and away from the press brake die.

20. A back gauge assembly of the type defined in claim 19 wherein stops are positioned at varying distances along the longitudinally extending grooves to limit the movement of said abutment means toward the press brake die.