US3446106A

US3446106A - Punch press with sliding bolster plate

Info

Publication number: US3446106A
Application number: US616620A
Authority: US
Inventors: Charles L Ferris; Robert J Babecki; Finn N Braathen; George J Sirovatka
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1967-02-16
Filing date: 1967-02-16
Publication date: 1969-05-27
Anticipated expiration: 1986-05-27

Description

May 27, 1969 C, 1 FERms ETA|. 3,446,106

PUNCH PRESS WITH SLIDING BOLSTEH PLATE Filed Feb. 16, 1967 Sheet of l5 saw wo E? 2 x Lf) grw vg *1 cw 3- O CO N m @l fr Thr k F N s'fm 2" g L Gl L (f3:

l s om' fr @32H Q I@ F2' mvENToRs CHARLES L. FERmS. "1 ROBERTJ. BABEcm, o FmN M.BRAATHENfn H GEORGE `Lsuzovrnm H ATroRNEYs May 27, 1969 c. l.. FERRIS ETAL 3,446,106

PUNCH PRESS WITH SLIDING BOLSTER PLATE Filed Feb. 16, 1967 sheet 2 @f5 @EB S t o y 1 [L Q l, m mr mfr \rn V W (l '0 Q C`I N cn N KD m INVENTOIB H CHARLES L. FERRnS, F'l

ROBERT J. BABECKI, r-mN M. BRAATHEN eb GEoRGE J. SIROVATKA Sheet mvENToRs CHARLES L. PERRvs neecu, QAATH 5,-, .slRov KA 96E@ C6521 R @www ATTORNEYS ROBERT J. FINN N. B GEORGE J C. L. FERRIS ET AL PUNCH PRESS WITH SLIDING BOLSTER PLATE Eli/M1..

May 27, 1969 Filed Feb. 16, 1967 HQE l l I I l l i l V l I l Irl May 27, 1969 c. l.. FERRIS vET AL 3,446,106v

PUNCH PRESS WITH SLIDING HOLSTER PLATE Filed Feb. 16, 1967 sheet 4 INVENTOR CHARLES' L. Femme., ROBERT J. BABEC KL pmu Hamm-HEM GEORGE J slRovATKA BY WLM/w, 61%. MM S :FIGS

ATTOR NIYS May 27, 1969 c. l.. FERRIS ET A1. 3,446,106

PUNCH PRESS WITH SLIDING BOLSTER PLATE Filed Feb, 16, 1967 sheet 5 of 5 INVENTORS CHARLES Lmams.

ROBERT J .BABECKL 2 N FINN N. BRAATHEM er E GEORGE J .SWOV/SKA United States Patent O 3,446,106 PUNCH PRESS WITH SLIDING BOLSTER PLATE Charles L. Ferris, Robert J. Babecki, and Finn N. Braathen, Chicago, and George J. Sirovatka, Berwyn, Ill., assignors to Union Special Machine Company, Chicago, Ill., a corporation of Illinois Filed Feb. 16, 1967, Ser. No. 616,620 Int. Cl. B26d 5/08, 5/22, 5/28 U.S. Cl. 83-400 17 'Claims ABSTRACT F THE DISCLOSURE A primary object of this invention is to provide a novel punch press which includes first means for reciprocating a bolster plate in a generally horizontal plane between a loading position and a work position, second means for reciprocating a ram for movement in a generally vertical plane between first and second positions remote from and adjacent the work position, die means carried by the bolster plate and the ram, control means for operating the rst and Second reciprocating means, the control means including first and second actuating means for respctively operating the first and second reciprocating means, and the second actuating means including means responsive to the movement of the bolster plate from the loading to the work position whereby the second actuating means actuates the second reciprocating means only upon the proper positioning of the bolster plate at its work position.

A further object of this invention is to provide a novel punch press of the type heretofore `described wherein the responsive means includes switch means closed by contact thereof with the bolster plate when the latter is properly at its work position.

Still another object of this invention is to provide a novel punch press which includes additional switch means associated with the first and second actuating means for operating the second actuating means only after the additional switch means has been at least once both closed and opened.

Yet another object of this invention is to provide a novel punch press of the type described wherein the bolster plate is guided during its reciprocal movement by dove-tail guide means, means are provided for slid-ably guidably connecting the bolster plate to a ram during at least a portion of the movement of the ram toward the work position for accurately relatively guiding the die members during a Work cycle of the press, and the latter-mentioned connecting means is defined by an axially registerable guide post and opening of the ybolster plate and ram.

A further object of this invention is to provide a novel punch press of the type heretofore defined wherein guard means are provided for preventing the introduction of an operators hands into an area at the work position, access means in the guard means through which the die member carried by the bolster plate passes when the latter moves between the first and second positions thereof, means for preventing the bolster from moving beyond its load position, and the last-mentioned means being in the form of a Ibiased pin carried by a frame of the press ICC adapted for reception in a relieved area of the bolster plate upon attempted movement of the latter beyond the load position.

Still another object of this invention is to provide a novel punch press of the type heretofore described wherein the first reciprocating means includes a uid motor, the uid motor is defined by a cylinder and an associated piston coupled to the bolster plate, means for selectively introducing and withdrawing iiuid from opposite ends of the piston cylinder, and a control circuit which includes means for regulating the operation of the fluid motor to prevent the premature return of the `bolster plate from the work position to the load position.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a front elevational view of a punch press constructed in accordance with this invention, and illustrates a reciprocal bolster plate and ram carrying cooperative die members.

FIGURE 2 is a side elevational view of the punch press of FIGURE 1, and illustrates a mechanism for operating a clutch t0 initiate the downward movement of the ram.

FIGURE 3 is a fragmentary elevational view of the rear of the press of FIGURES 1 and 2, and illustrates a fluid-motor and associated conduits for effecting the reciprocal movement of the bolster plate.

FIGURE 4 is a fragmentary schematic front view of the punch press of FIGURES 1 through 3, and illustrates .a guard through which the `bolster plate passes during its reciprocal movement 'between loading and work stations.

FIGURE 5 is a fragmentary sectional view taken generally along line 5 5 of FIGURE 4, and illustrates the manner in which the guard surrounds the are-a at the work station.

FIGURE 6 is an enlarged sectional view taken generally along line 6-6 of FIGURE 1, and illustrates the bolster plate at the work station and switches actuated thereby to control the operation of the ram.

FIGURE 7 is a sectional view taken generally along line 7 7 of FIGURE 6 and illustrates a spring biased pin adapted for reception in a relieved area of the bolster plate when the latter is at the load station.

FIGURE 8 is a sectional view taken generally along line 8-8 of FIGURE 6, and illustrates the sliding dovetail connection between the bolster plate and guide rails of the press.

FIGURE 9 is a top perspective view of a die set of the press, and illustrates aligned guide posts and openings for registering the die members during the downward stroke of the ram.

FIGURE 10 is a side elevational view of a mechanism for operating the ram clutch, and illustrates a spring biased member for operating a switch through a solenoid.

FIGURE 11 is a fragmentary front perspective view of the press guard, and more clearly illustrates the construction thereof.

FIGURE 12 is a circuit diagram illustrating the circuitry for controlling the operation of the ram and the bolster plate.

A novel punch press constructed in accordance with this invention is generally illustrated in FIGURES l through 3 of the drawings, and is designated by the ref erence numeral 20. The punch press 20 includes .a frame 21 to which is conventionally pivotally and adjustably mounted two upright support or

frame lmembers

22, 23.

A plate 24 (FIGURE 2) bridges the

frame members

22, 23 and is secured thereto by conventional means (not shown). A plate 25 is secured to the plate 24 andl in turn carries a support 26 for an electric motor 27 which is energized by a conventional electrical source (not shown) The motor 27 includes an output shaft 28 (FIGURE 1) to which is secured a drive pulley 30. A plurality of pulley belts 3.1 are entrained about the drive pulley 30 and a ywheel 32 freely rotatably journalled on a shaft 33. The shaft 33 is journalled for rotation by conventional means (unnumbered) in the

frame members

22, 23. A conventional clutch 34 is operated by a mechanism to be described more fully hereafter for selectively coupling the ywheel 32 to the shaft 33 thereby imparting rotation to the latter.

The portion of the shaft 33 between the frame members 22, 33 (FIGURE l) includes an eccentric 35. A split housing 36 couples the eccentric 35 to a press ram 37 which is in turn guided for reciprocal movement in a vertical plane by conventional guides 38, 40. Each time the clutch 34 is actuated the shaft 33 and the eccentric 35 are rotated one revolution and in turn reciprocate the ram 37 through one cycle.

A plate 41 (FIGURES 1 and 9) is connected to the ram 37 and includes a pair of openings (unnumbered) in which `are fixed downwardly directed

tubular guide sleeves

42, 43. The lowermost internal surfaces of the guide sleeves or

bushings

42, 43 are chamfered for facilitating the introduction of

guide posts

44, 45 into the

respective sleeves

42, 43. The

guide posts

44, 45 are carried by a die holder 46 attached to a bolster plate 47. The progressive sliding engagement between the

vguide posts

44, 45 and the

sleeves

42, 43 during the downward movement of the press ram 37 assures the accurate alignment between die

members

48, 50 carried by the plate 41 and the die holder 46, respectively.

The bolster plate 47 is mounted for sliding movement in a horizontal plane atop a plate 51 which is in turn secured to a platform portion 52 (FIGURES 6, 7 and 8) of the

frame members

22, 23 by conventional bolts 53. The bolster plate 47 is provided with .a generally rectangular opening 54 which is in alignment with

openings

55, 56 of the plate 51 and the platform portion 52, respectively, when the bolster plate is at its innermost or working position (FIGURE 6). The purpose of the openings 54 through 56 is to permit metal chips to pass therethrough when the punch press 20 is employed to perform a trimming or similar metal-removing operation on workpieces.

The bolster plate 47 includes an innermost edge or face 57 and

opposite edge portions

60, 61 having edges (unnumbered) in downwardly diverging relationship, as is best illustrated in FIGURE 8 of the drawings. The edges of the

edge portions

60, 61 of the bolster plate 47 are in mating sliding engagement with similar edges of a pair of

rails

62, 63 secured to the plate 51 by conventional fasteners 64, such as bolts. The dove-tail sliding connection :between the

guide rails

62, 63 and the

edges

60, 61 of the bolster plate 47 permit the latter to reciprocate in a horizontal plane but vertical movement thereof is prevented. The bolster plate 47 is also provided with a plurality of threaded apertures 65 for receiving bolts (unnumbered) which secure any one of a variety of different types of die holders upon the bolster plate 47.

The plate 51 is provided with a pair of bores (unnumbered) which each receive a pin 66 biased upwardly as viewed in FIGURE 7 by a compression spring 67. Each of the pins 66 is adapted to be received in a relieved area or opening 68 of the bolster plate 47. (FIGURE 7). The interlocked pins 66 and openings 68 thereby serve as locking means to prevent injury to an operator should the bolster plate break free of a piston rod 72 during its return from the work position or station to the loading position or station.

The bolster plate 47 is reciprocated by means of a iluid motor, generally designated by the reference numeral 70. The fluid motor 70 includes a cylinder 71 in which is reciprocally. mounted a piston (not shown) carrying the piston rod 72 connected to the bolster plate 47 by conventional means. The uid motor 70 is secured to the platform portion 52 of the

frame members

22, 23 by conventional fasteners 73, and

fluid conduits

74, 75 open into the interior of the chamber (unnumbered) of the cylinder 71 at opposite sides of the piston (not shown). 'A valve 76 in the line 75 is manually adjusted to regulate the incoming uid (air under pressure) which through the piston and piston rod 72 draws the bolster plate 47 inwardly against stops 77, 78 threadedly secured in bores (unnumbered) of a pair of stop blocks 79, 89, respectively, secured to the platform portion 52 in a conventional manner. By regulating the incoming iluid pressure such that it is slightly greater than the build-up of back pressure on the other side of the piston a quiet and very quick stop of the bolster plate 47 is obtained.

The conduit 75 is placed in iluid communication with a conventional source of pressurized uid, such as compressed air, by means of a solenoid valve 80 having a solenoid 81 (FIGURE 12), a conduit 82, a conventional lubricator 83, a conventional valve 84 having a pressure gauge (unnumbered), a filter 85, a conduit 86, a T-coupling 87 and a conduit 88. The conduit 74 is also placed in Huid communication with the uid pressure source by means of a solenoid actuated valve 90 having a coil 91 (FIGURE 12), the conduit 82, the lubricator 83, the valve 84 the filter 85, the conduit 86, the T-coupling 87 and the conduit 88. The operation of the punch press, particularly with respect to the operation of the solenoid valves 80, 90, will be described more fully hereafter in conjunction with a control circuit (FIG- URE 12) of the press 20.

Switches

92, 92a (FIGURE l) having switch arms 93, 93a (FIGURE l2) are located above the split housing 36 of the ram 37 by a conventional bracket (unnumbered) The switch arms 93, 93a are positioned for actuation by contact with the split housing 36 during the movement of the latter as the shaft 33 rotates in a manner and for a purpose which will be described hereinafter.

The clutch mechanism 34 corresponds to the clutch mechanism disclosed in Letters Patent 1,604,598 in the name of Herman Osswald issued Oct. 26, 1926. The clutch 34 is actuated by a mechanism 105 (FIGURES 2 and 10). The mechanism includes a hook latch 106 corresponding to the latch 15 of the latter-noted Letters Patent. The latch 106 is mounted for pivoting movement about a conventional pivot pin 107 secured to the frame member 23. An arm 108 of the latch 106 is secured to a rod 110 which is in turn conventionally connected to a member 111 having an elongated slot 112. The member 111 is connected to one end of a piston rod 113 whose opposite end includes a piston (not shown) housed in a cylinder 114. The cylinder 114 includes a bracket 115 secured to the frame member 23 by a screw 116. A compression spring 117 surrounds the piston rod 113 and is positioned between the cylinder 114 and the member 111 to normally bias the latter upwardly as viewed in FIGURE 10 of the drawings.

A switch 118 (FIGURES 10 and 12) includes a switch arm 120 having a roller 121 received in the slot 112 of the member 111. The switch 118 is secured by conventional bracket means and fasteners (not shown) to the frame member 23.

The mechanism 105 is shown in FIGURE 10 of the drawings in the position in which the latch 106 maintains clutch portions of the clutch 34 disengaged whereby the flywheel 32 rotates freely upon the motionless shaft 33. The latch 106 is disengaged to activate the clutch 34 and rotate the shaft 33 by means of a solenoid actuated valve 123 (FIGURES 2, 3, 10 and 12) which includes a coil 124 (FIGURE 12). When the solenoid valve 123 is energized fluid under pressure is introduced into the cylinder 114 above the piston (not shown) to draw the rod 113 downwardly which in turn pivots the latch 106 about the pivot pin 107 and actuates the clutch 34 to rotate the shaft 33 through one revolution, as vwill be more apparent hereafter.

41 The interior of the cylinder 114 is placed into fluid communications with the fluid pressure source by a conduit 125, the solenoid 123, a conduit 126 (FIGURE 3), a lubricator 127, a conventional valve 128 having a pressure gauge, a filter 130, the T-coupling 87 and the conduit 88.

The punch press 20 further includes a pair of switches 131, 133 (FIGURES l and 12) having respective switch

arms

132, 134 which are normally open but can be closed by an operator of the lpress by depressing respective push buttons 135, 136.

Two additional switches 137, 140 (FIGURES 6 and l2) having

switch arms

133, 141, respectively, are mounted above the platform portion 52, (FIGURE 6) of the

frame members

22, 23 in alignment with the

edge portions

60, 61, respectively, of the bolster plate 47. The

switches

137, 140 are normally open and are closed when the bolster plate 47 reaches the position illustrated in FIGURE 6 of the drawings.

The punch press 20 is preferably though optionally provided with a guard 145 (FIGURES 4, 5 and 11) which includes a generally U-shaped horizontally disposed tubular member 146 provided with a plurality of vertically disposed pairs of

apertures

147, 148.

Legs

150, 151 of an elongated U-shaped member 152 are received in

respective openings

147, 148 of the member 146. A set screw 153 seats against the leg 150 of each of the members 152 and maintains the members 152 in any position of vertical adjustment depending for the most part upon the size of the die holder 46, the die member 50 and the size of the workpiece. In the illustrated embodiment of the invention the ve centermost members 152 (FIGURE 4) are shown raised above the remaining members 152 to define an access opening (unnumbered) through which the bolster plate 47, the die holder 46, the die member S and the workpiece can pass during the reciprocation of the bolster plate between the loading and Working stations thereof (FIGURES and 6) respectively.

The operation of the punch press 20 is initiated by rst closing a main switch 160 of the control circuit 100 (FIG- URE 12) which illuminates a lamp 161 over a circuit traced from a power input line 162, the now closed switch 160, a conductor 163, a conductor 164, the lamp 161 and a conductor 165 to ground. The lamp 161 is preferably mounted at a readily visible location at the front of the press.

Assuming the bolster plate 47 is at the loading station (FIGURE 5), the operator places a suitable workpiece upon the die member 50 and depresses the push buttons 135, 136 to close the normally open contacts of

switch arms

132, 134 of the

respective switches

131, 133. The

contacts

132, 134 arec onnected to normally closed contacts 166, 167 and 168, 169, respectively. Thus, when the

contacts

132, 134 are closed the contacts 166 through 169 are opened. The closing of the

contacts

132, 134 also energizes a coil 170 of a relay 171 over the conductor 163, a conductor 172, the coil 170, a conductor 173, the now closed

switches

132, 134, a conductor 174 and ground. The energized coil 170 closes a switch 175 to provide a holding circuit for the relay 171 over the conductor 163, the conductor 172, the coil 170, the conductor 173, a conductor 176, the now closed switch 175, a conductor 177, a normally closed switch 178, a conductor 180, the normally closed switch arm 93 of the switch 92, a conductor 181, the conductor 174 and ground.

The energized coil 170 of the relay 171 closes a switch arm 182 to energize the coil 81 over a path traced from the conductor 163, a conductor 183, the coil 81, a conductor 184, the now closed switch 182 and a conductor 185. The coil 81 actuates the solenoid valve 80 and uid pressure from the pressure source over the ow path heretofore described enters the cylinder 71 through the conduit 75 to pull the bolster plate 47 from the load position through the access area in the guard 145 to the Work position (FIGURE 6) beneath and in vertical alignment with the ram 37. The end face 57 (FIGURE 6) of the bolster plate 47 closes the

contact arms

138, 141 of the

respective switches

137, 140. However, since the

switches

131, 133 have not yet been released the contacts 166 through 169 remain open until the operator releases the

switches

131, 133. Upon the release of the

switches

131, 133 the

contacts

132, 134 open, the coil 170 of the relay 171 remains energized over the holding circuit heretofore described, and a coil 186 of a relay 187 is energized over a path traced from the conductor 163, a conductor 188, a resistor 190, a conductor 191, a resistor 192, the coil 186, a conductor 193, switch 92a, a rectifier 194, the now closed contact 138 of the switch 137, and the closed contacts 166, 168.

The energized relay 187 closes a switch 195 to energize the coil 124 of the solenoid valve 123 over a circuit traced from the conductor 163, a conductor 196, the coil 124, a conductor 197, the now closed switch 195, a conductor 198, a now closed switch 200 of the relay 171, a

conductor 201, the closed contact 141 of the Vswitch 140,

and a conductor 201. Upon the operation of the solenoid valve 123 fluid pressure from the source enters the cylinder 114 (FIGURE 10) over the ow path heretofore described to draw the piston rod 113 downwardly or inwardly causing the latch 106 to pivot in a clockwise direction whereupon the clutch 34 is actuated to couple the rotating ywheel 32 to the shaft 33 which in turn reciprocates the ram through one cycle and the workpiece is appropriately operated upon by the

cooperative die members

48, 50.

At the same time the solenoid valve 123 is actuated to initiate the movement of the ram 37 the normally closed switch arm 120 opens switch 118 (FIGURE 10) by the downward movement of the member 111. This prevents the bolster plate 47 from prematurely leaving the work station upon the de-energizing of the relay 171 when the contact 93 of the switch 92 opens. That is, during the initial energizing of the coil 170 of the relay 171 a normally closed contact or switch 205 is opened to prevent the coil 91 from being energized when the switch 120 is in its normally closed position. In the absence of opening the switch 118 during the energizing of the solenoid valve 123 the coil 170' of the relay 171 could de-energize prematurely upon the opening of the switch 92 as the ram 37 beings to descend whereupon the switch 205 would close prematurely and begin withdrawing the bolster plate 47 toward its load position prior to the complete cycling of the ram 37.

The closing of the switch 120 energizes the coil 91 of the solenoid over a circuit traced from the conductor 163, the coil 91, a conductor 207, the now closed switch 120, a conductor 208, the switch 205 of the de-energized coil 171, a conductor 210 and the normally closed switches 167, 169. The coil 91 actuates the solenoid valve 90 to introduce uid into the cylinder 71 in the manner heretofore described through the conduit 74 to move the bolster plate 47 to its loading position at which point the cycle just described can be repeated. The movement of the bolster plate 47 toward the loading station opens the contacts or switches 138, 141 while the return of the ram 37 closes the

switches

92, 92a to restore the circuit V to its initial condition. The operation of the punch press and its related circuitry as just described results in the continuous reciprocation of the bolster plate 47 and the ram 37 each time the

switches

131, 133 are depressed and released. However, it is at times desirable, particularly when operating upon long strips of sheet metal, to lock the bolster plate 47 in the work position thereof against the stops 77, 78. This isaccornplished by opening the normally closed switch 178 and cutting off uid flow from the pressure sounce to the solenoid valves 80, 90 by conventional valve means (not shown). With the bolster plate 47 holding the

contacts

138, 141 closed and with the switch 178 open the energizing of the coil 170 of the relay 171 is ineffective to reciprocate the bolster plate due to the cutting-off of fluid pressure to the cylinder 71 and a holding circuit is not established. Strip material can therefore be fed sideways to the punch press in a continuous fashion so long as the

switches

131, 133 are closed. To insure positive action when the sliding action of the bolster plate 47 is not used, a feed-back circuit is provided which maintains the coil 124 of the solenoid valve 123 energized after the relay 171 has been de-energized by the opening of the normally closed contact 93 of the

switches

92, 92a upon the dovmward movement of the ram 37. During the same time the coil 186 of the relay 187 is energized the rectifier 194 charges a capacitor 206 across the

conductors

163, 193. When the switch 92 opens breaking the holding circuit and de-energizing the relay 171, coil 186 of the relay 187 remains energized as current from the capacitor bleeds into the coil 186 of the relay 187 resulting in the continued energizing of the coil 124 over the conductor 196, the coil 124, the conductor 197, the still closed switch 195 to positively insure that the relay 187 and the coil 124 will remain activated for as long as the relay 171 is energized. After the coil 186 de-energizes current to the coil 124 of the solenoid 123 is cut olf and the spring 113 (FIGURE 12) forces the member 111 upwardly to close the contact 120 of the switch 118. The rotation of the shaft 33 opens the switch 92 breaking the

holding circuit

170, 172, 175, 176, 177, 178, de-energizing the relay 171. In addition, rotation of the shaft 33 also opens the switch

92a opening circuit

163, 190, 192, 186, 193, 92a, 194, 138, 166 and 168.

We claim:

1. A punch press comprising a frame, means mounting a bolster plate for movement upon said frame, first means for reciprocating said bolster plate between a first loading position and a second work position, a rst die member carried by said bolster plate and movable therewith, a ram mounted for movement relative to said frame, second means for reciprocating said ram between first and second relatively displaced positions respectively remote from and adjacent said work position, a second die member carried by said ram and cooperative with said first die member, said die members being in offset relationship in said first positions and in alined relationship in said second positions, control means for operating said rst and second reciprocating means, said control means including first actuating means for actuating said first reciprocating means to move said bolster plate from the first to the second position thereof, and second actuating means for actuating said second reciprocating means to move said ram at a time the bolster plate is at its second position thereby altering a work piece positioned between said die members.

2. The punch press as defined in claim 1 wherein said second actuating means includes means responsive to the movement of said bolster plate during the movement thereof from the -first toward the second position whereby said second actuating means actuates said second reciprocating means only when said bolster plate is at its second position. v

3. The punchpress as defined in claim 1 wherein said second actuating Ymeans includes means responsive to the movement of said bolster plate, and said responsive means includes contactable switch means positioned for operation by the movement of said bolster plate at said work position.

4. The punch press as defined in claim 1 including switch means associated with said first and second actuating means for operating said second actuating means only after said switch means has been at least once closed and opened.

5. The punch press as defined in claim 1 including means slidably guidably connecting said bolster plate to said ram during at least a portion of the movement of said ram toward its work position for accurately relatively guiding said die members during a work-cycle of the press.

6. The punch press as defined in claim 1 including means slidably guidably connecting said bolster plate to said ram during at least a portion of the movement of said ram toward its work position for accurately relatively guiding said die members during a work-cycle of the press, and said connecting means being in the form of an axially registerable guide post and opening.

7. The punch press as defined in claim 1 including guard means for preventing the introduction of an operators hands into an area at the work position of the bolster plate, and access means in said guard means through which said rst die member passes when moving with said bolster plate between the first and second positions thereof.

8. The punch press as defined in claim 1 wherein abutment means are provided for accurately positioning said bolster plate at said second position, and said second actuating means include switch means adjacent said abutment means for operation'by the movement of said bolster plate toward the second position thereof.

9. The punch press as defined in claim 1 wherein said mounting means includes a pair of spaced rails between which said bolster plate is located, adjacent edges of said rails are undercut, and remote edges of said bolster plate are receieved beneath said undercut edges.

10. The punch press as defined in claim 1 including means for preventing said bolster plate from moving beyond said first position and said last-mentioned means being in the form of a biased pin carried by said frame adapted for reception in a relieved area of said bolster plate.

11. The punch press as defined in claim 1 wherein said first reciprocating means includes a duid motor, said fluid motor includes a piston having a rod connected to said bolster plate, means for selectively introducing and withdrawing uid from opposite ends of a poston cylinder of said uid motor, abutment means for accurately positioning said bolster plate at said second position, and said second actuating means include switch means adjacent said abutment means for operation by the movement of said bolster plate toward the second position thereof.

12. The punch press as defined in claim 1 wherein said rst reciprocating means includes a uid motor, said uid motor includes a piston having Aa rod connected to said bolster plate, means for selectively introducing and withdrawing uid from opposite ends of a piston cylinder of said fluid motor, abutment means for accurately positioning said bolster plate at said second postion, said second actuating means include switch means adjacent said abutment means for operation by the movement of said bolster plate toward the second position thereof, said mounting means includes a pair'of spaced rails between which said bolster plate is located, adjacent edges of said rails are undercut, and remote edges of said bolster plate are received beneath said undercut edges.

13. The punch press as defined in claim 1 wherein said first reciprocating means includes a uid motor, said fluid motor includes a piston having a rod connected to said bolster plate, means for selectively introducing and withdrawing fluid from opposite ends of a piston cylinder of said uid motor, abutment means for accurately positioning said bolster plate at said second position, said second actuating means include switch means adjacent said abutment means for operation by the movement of said bolster plate toward the second position thereof, said mounting means includes a pair of spaced rails between which said bolster plate is located, adjacent edges of said rails are undercut, remote 'edges of said bolster plate are received beneath said undercut edges, means slidably guidably connecting said bolster plate to said ram during at least a portion of the movement of said ram toward its work position for accurately relatively guiding said die members during a work-cycle of the press, and said connecting means being in the form of an axially registerable guidepost and opening.

14. The punch press as defined in claim 1 wherein said first reciprocating means includes a fluid motor, said fiuid motor includes a piston having a rod connected to said bolster plate, means for selectively introducing and withdrawing fiuid from opopsite ends of a piston cylinder of said fluid motor, abutment means for accurately positioning said bolster plate at said second position, said second actuating means include switch means adjacent said abutment means for operation by the movement of said bolster plate toward the second postion thereof, said mounting means includes a pair of spaced rails between which said bolster plate is located, adjacent edges of said rails are undercut, remote edges of said bolster plate are received beneath said undercut edges, means slidably guidably connecting said bolster plate to said ram during at least a portion of the movement of said ram toward its work position for accurately relatively guiding said die members during a work-cycle of the press, said connecting means being in the form of an axially registerable guide post and opening, guard means for preventing the introduction of an operators hands into an area at the work position of the bolster plate, and access means in said guard means through which said first die member passes when moving with said bolster plate between the first and second positions thereof.

1S. The punch press as defined in claim 1 wherein said first and second actuating means form portions of a con f.

trol circuit of said control means, and said control circuit includes means for temporarily preventing the premature return of said bolster plate from said work position to said first position during and after one complete cycle of movement of said ram.

16. The punch press as defined in claim 1 wherein said first and second actuating means form portions of a control circuit of said control means, first and second relay means for operating said first and second reciprocating means respectively, first solenoid means energized by said first relay means for effecting the movement of said bolster plate from said first toward said second position, second solenoid means energized by said first relay means for effecting the movement of said bolster plate from said second to said first position, third solenoid means energized by said second relay means for effecting the operation of said second reciprocating means, and switch means associated with said second solenoid means for energizing the latter only upon the return of said second reciprocating means to said first position.

17. The punch press as defined in claim 1 wherein said first and second actuating means form portions of a control circuit of said control means, first and second relay means for operating said rst and second reciprocating means respectively, first solenoid means energized by said first relay means for effecting the movement of said bolster plate from said first toward said second position, second solenoid means energized by said first relay means for efecting the movement of said bolster plate from said second to said first position, third solenoid means energized by said second relay means for effecting the operation of said second reciprocating means, land bleed-back circuit means for maintaining said second relay and said third solenoid energized after input to said relay is discontinued, switch means associated with said second solenoid means for energizing the latter to effect the movement of the bolster plate from the second to the first position, and said switch means is coupled to said third solenoid and maintained open until said second relay is de-energized through said bleed-back circuit means.

References Cited UNITED STATES PATENTS Re. f8,l62 8/1931 Freeman 83H221 2,176,543 10/1939 Norton 83--563 2,566,243 8/1951 Nyquist 83-221 X 2,910,727 11/ 1959 Salbeck et al 100-229 X 2,988,234 6/ 1961 Barothy et al.

ANDERW R. JUHASZ, Primary Examiner.

FRANK T. YOST, Assistant Examiner.

U.S. Cl. X.R.