US3564995A

US3564995A - Reciprocating press and work feed mechanism therefor

Info

Publication number: US3564995A
Application number: US721504A
Authority: US
Inventors: Gilbert Rodli; Robert Glenn Corbin; Walter N Nelson; Maynard C Nelson
Original assignee: JOHN R WALD CO Inc
Current assignee: JOHN R WALD CO Inc
Priority date: 1968-04-15
Filing date: 1968-04-15
Publication date: 1971-02-23
Anticipated expiration: 1988-02-23

Abstract

Three bolsters are positioned between the ram and bed of a press. Dies are mounted between each two bolsters and are vertically disposed to provide a two-stage press in which a single cycle of the ram operates both sets of dies. A work feed mechanism is provided for moving one workpiece from a first support laterally and downwardly to the upper dies and a second workpiece from a second support laterally and downwardly to the lower dies. The work feed mechanism also retracts the workpieces, and moves the one workpiece to the second support for subsequent feeding to the lower dies. Thus, a workpiece is sequentially fed to the two-stage press in a cascadelike feeding movement.

Description

United States Patent [54] RECIPROCATING PRESS AND WORK FEED MECHANISM THEREFOR 17 Claims, 10 Drawing Figs. [52] US. Cl 101/3, 271/54 [51] Int. Cl 341k 3/00, 1365b 5/16 [50] Field of Search 72/1;

101/28, 3, (Curso 'y); 40/200; 271/54, 3, 9, (Cursory); 214/(Cursory); 198/19, 20, (Cursory); 72/419, 405; 101/296, 287

Primary Examiner-William B. Penn Assistant Examiner-E. M. Coven Attorney-Me Canna, Morsbach, Pillote and Muir ABSTRACT: Three bolsters are positioned between the ram and bed of a press. Dies are mounted between each two bolsters and are vertically disposed to provide a two-stage press in which a single cycle of the ram operates both sets of dies. A work feed mechanism is provided for moving one workpiece from a first support laterally and downwardly to the upper dies and a second workpiece from a second support laterally and downwardly to the lower dies. The work feed mechanism also retracts the workpieces, and moves the one workpiece to the second support for subsequent feeding to the lower dies. Thus, a workpiece is sequentially fed to the two-stage press in a cascadelike feeding movement.

PATENTEU FEB23I97| v sum 1 [IF 6 PATENTED H523 IHYI SHEET 2 BF 6 PATENTED FEB23 1971 v 3554.995

SHEET 3 OF 6 PATENTEU FEB23I97I I $554,995

sum 5 or e RECIPROCATING PRESS AND WORK FEED MECHANISM THEREFOR BACKGROUND The invention pertains to reciprocating presses and work feed mechanisms therefor.

By way of example, the present invention is described as utilized in the manufacture of license plates. License plates are impressed in two stages: one containing indicium which is common to all plates (i.e., the state, year, and rim), and the indicium which changes for each set of plates. The latter, which is commonly numerals and letters, is applied by individual book-type dies such as shown in U.S. Pat. No. 1,563,124 issued Nov. 24, 1925. These dies must be easily inserted and removed from the press, yet their proper positioning is important since misplacement will result in scrap work.

SUMMARY The present invention relates generally to reciprocal presses and to work feed mechanisms which may be used therewith. More particularly, the present invention relates to a multistage reciprocal press and to a work feed mechanism which moves a workpiece from one level to a work station and then moves it from the work station to a level below the one level.

It is an object of the present invention to provide a new and useful work feed mechanism for moving a workpiece from one level to a work station and therefrom to a level below the one level.

Another object is to provide a work feed mechanism in accordance with the foregoing object in which the work feed thereafter moves the workpiece to a second work station at a level below the first work station.

Still another object is to provide a work feed mechanism in accordance with the foregoing objects in which the work stations are generally vertically disposed and the mechanism reciprocates to move the workpiece sequentially to the stations in a cascadelike movement.

Yet another object of the present invention is to provide a new and useful work feed mechanism for moving a workpiece to and from a work station which performs an operation on the workpiece, and wherein the mechanism moves in one direction to position the workpiece, and retracts in a direction opposite said one direction to remove the workpiece.

It is another object of the present invention to provide a new and useful multistage reciprocal press for concomitantly performing operations on at least two different'workpieces.

Another object is to provide a press in accordance with the foregoing object in which the press has vertically disposed work stations and the operations are performed by a single operation of a ram.

It is still another object to provide a press in accordance with the two foregoing objects and including feed means for sequentially moving a workpiece between the work stations.

Another object of the present invention is to provide an apparatus including removably mounted die means for performing an operation on a workpiece, feed means for moving the workpiece to the die means, and means for controlling the feed means to prevent actuation thereof in the absence of the die means.

Other objects are to provide an apparatus which is safe in operation, which minimizes the amount of scrap, and which has a relatively high rate of production.

These, together with other objects and advantages of the present invention, will become apparent as the same becomes better understood from the following detailed description when taken in conjunction with the accompanying drawings.

DRAWINGS FIG. 1 is a perspective view of an embodiment of the present invention;

FIG. 2 is a longitudinal sectional view of the apparatus taken generally along line 2-2 in FIG. 6;

FIG. 3 is a longitudinal sectional view similar to FIG. 2 but with the feed mechanism, dies, and bolsters in moved positions;

FIG. 4 is a sectional view taken generally along line 4-4 of FIG. 2;

FIG. 5 is a sectional view taken generally along broken line 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view taken along broken line 6-6 of FIG. 2;

FIG. 7 is a diagrammatic view of a control circuit for the present invention; and

FIGS. 8-10 are diagrammatic views illustrating the operation of the present invention.

DESCRIPTION The term press as used herein is intended to be a generic term which includes, for example, hydraulic presses, punch presses, press brakes, and the like.

Reference is now made more particularly to the drawings which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the several views.

The apparatus illustrated in the drawings is adapted for use on existing equipment which has jaws, such as a ram 16 and a bed 18, and means 19 for effecting. relative movement of the ram and bed toward and away from each other in a reciprocating fashion. In the embodiment illustrated, this relative movement is advantageously a vertical movement for a purpose which will hereafter become apparent.

In the embodiment illustrated, three bolsters are mounted between the ram 16 and the bed 18 to define first and second work .stations. An upper bolster 22 is carried by the ram 16 and is mounted thereon in any convenient manner. A lower bolster 24 is carried by the bed 18 and may be mounted or clamped thereon in any convenient manner. An intermediate bolster 26 is disposed between the upper and lower bolsters. The intermediate bolster 26 is advantageously supported by, and resiliently urged away from, one of the other bolsters so that the bolsters are spaced from each other in an open position. Forthis purpose, a plurality of dowels 31 extend through the intermediate bolster 26 and are secured in the lower bolster 24. A compression-type spring 32 is conveniently circumjacent each dowel and bears against the lower and intermediate bolsters. It is contemplated that the springs 32 may be otherwise located, if desired. Each dowel has a head.3la to limit the spring-urged upward movement of the intermediate bolster at the open position. When the ram 16 moves downwardly, the upper bolster 22 is operatively engaged with the intermediate bolster 26, and the force of the ram overcomes the force of springs 32 and moves the intermediate bolster toward the lower bolster 24 to a closed or impressing position. To guide the movement of the intennediate bolster between its positions, a pair of short columns 34 are provided. These columns are advantageously secured in the lower bolster 24 and slidablyreceived in the intermediate bolster 26. A bushing 36 is mounted on the intermediate bolster to receive the column 34 and depends a preselected distance for engaging the lower bolster 24 to provide a stop at the closed position. Other stop arrangements may be utilized, as is convenient.

In the embodiment illustrated, a set of dies is mounted between each two bolsters to perform an operation on a workpiece. Reference is now made to FIGS. 810 for a general description of the basic operation. One or more book-type dies, generally designated D-l, are located at the first work station between bolsters 22 an 26. These dies may be of the type shown in the aforementioned U.S. Pat. No. 1,563,124, and reference is made thereto for a more complete description. At the second work station, between bolsters 24 and 2.6, are mounted upper and lower matching dies D-2 and D-2', respectively. As will hereinafter be more fully described, the upper and lower sets of dies are vertically disposed to provide a two-stage press in which a single cycle of the ram operates both sets of dies.

A work feed mechanism is provided for feeding a workpiece, such as a license plate blank 40, forwardly into position between the first dies D-l, then rearwardly to retract the partially formed piece from the press, then forwardly at the second station into position between the second set of dies D-2, D-2', and finally rearwardly to retract the formed piece. For this purpose, a first support 42 is disposed laterally of the work stations and at a level above the surface onto which the workpiece 40 is to be fed. Similarly, a second support 44 is located at a level below the first support and below the first station, but above the surface of the second station onto which the workpiece is to be fed. An upper pusher 46 is provided for pushing the workpiece 40 from the first support laterally and downwardly to the first work station. Simultaneously, a second pusher 48 operates to push a second workpiece 40 from the second support 44 laterally and downwardly to the second work station. This is the position shown in FIG. 9, and the movement of the workpieces is shown by the arrows.

The press is then operated to move the ram through a cycle so that workpieces 40 and 40' are impressed or have another working operation performed thereon. Upper and

lower retracting fingers

52 and 54, respectively, operate to retract the

workpieces

40 and 40, respectively, as shown in FIG. 10. Workpiece 40 is retracted laterally and downwardly to second support 44 while the other workpiece 40' is retracted laterally and downwardly to a level below the second support. This is the position shown in FIG. 10, and the movement of the workpieces is shown by the arrows.

The book dies D1 are then changed to another number, for example, and the operation repeated for subsequent workpieces. It can be seen that a workpiece is sequentially fed to the first work station and then to the second work station in a cascadelike feeding movement. This allows two separate operations to be quickly and easily performed on a single workpiece.

To describe the apparatus in greater detail, reference is made to FIGS. 2-6. Upper pusher fingers 46, 46' and upper retractor fingers 52, 52' are carried by a generally U-shaped plate 56, as best seen in FIGS. 4 and 6. At the ends of U- shaped plate 56 are slide blocks 57, 57' slidably mounted in upper guide rails 62, 62'. The upper guide rails are secured to intermediate bolster 26 in any convenient manner for vertical movement therewith.

Lower guide rails

64, 64 are secured to lower bolster 24 in any convenient manner. A cross plate 65 is secured to the lower guide rails and operates as a mount for the lower or second supports 44, 44'. A generally U-shaped plate 66 is provided with slide blocks 67, 67 at its opposite ends. The slide blocks are slidably received in the lower guide rails for reciprocal movement therealong. Plate 66 carries the lower pusher fingers 48, 48' and the lower retractor fingers 54, 54'. Also mounted on plate 66 is an upright 72 and mounting

blocks

73, 74 therefor (See FIG. Upper U-shaped plate 56 is slotted to receive upright 72 therethrough as best seen in FIG. 4, and has upper and lower slide blocks 75, 76, respectively, for mounting the U-shaped plate 56 for vertical movement relative to the upright 72.

A generally U-shaped support bracket 80 is secured to support plate 65 in a generally central location. Support bracket 80 carries a pneumatic cylinder 82 which has a rod 84 extending therefrom and secured to the upright 72. In this manner, reciprocation of the rod 84 reciprocates the upright 72, thereby causing movement of the pusher fingers and retractor fingers. In the manner described above, the pneumatic piston 82 controls the insertion of the work plates from the supports into the dies and also the retraction of the workpieces from the dies. Additionally, the feed mechanism for feeding into the upper die D--l is mounted for vertical movement with the intermediate bolster 26.

Lower guide rails 64 and 64' support a housing which consists of side members 90, 90' and a top member 91, as best seen in FIG. 6. Top member or plate 91 extends along the front of the press and has an opening 92 through which the workpiece may drop onto the first support 42 (See FIG. 2). A slotted guard 94 is spaced above the top plate 91 a distance sufficient to allow the workpiece or license plate to be slid therebetween by an operator. A window 95, conveniently made of plexiglass, is provided for visual inspection of the mechanism. It can be seen that the support 42 is positioned below the opening 92 and in front of the first work station, but at a level above the lower level of die 04. The upper pusher fingers 46, 46' are provided to push the workpiece off the first support 42, laterally and downwardly into die D-l. The pusher fingers remain in the forward position during the forming operation. After forming, pneumatic cylinder 82 is operated, thereby retracting the

retractor fingers

52, 52 to draw the partially formed workpiece from the first die D-l, laterally in a direction opposite the first direction, and downwardly onto second support 44.

A combination swinging deflector and barricade, generally designated 96 (See FIGS. 2 and 3) aids in the above operations. This combination apparatus 96 includes a stationary portion 97 and a swinging portion 98. When a workpiece is first inserted by an operator, its edge will strike the stationary portion and then drop straight down onto

upper supports

42, 42. When advanced by the upper pusher fingers 46, 46', the workpiece strikes the swinging portion 98 which swings to the position shown in phantom in FIG. 2 and guides the workpiece downwardly into the die D-l. When the workpiece is retracted by fingers 52, 52', the swinging portion 98 swings to the other phantom position against the underside of upper supports 42, 42'. This guides the workpiece downwardly toward the lower or second supports 44, 44'.

To further guide the workpieces downwardly and to aid in positioning the workpiece on the second support, a pair of deflectors 101, 101' are mounted beside the second supports 44, 44, respectively. The deflectors are provided with an arcuate front face extending upwardly and forwardly to a level slightly above the lower surface of die D-l. The deflectors have a recess, as at 101a (See FIGS. 2 and 3), to receive the edge of the workpiece and assure that it is properly positioned on the lower or second supports. Sideplates 102, 102' are mounted on upper guide rails 62, 62' to position the workpieces in a crosswise direction. On a subsequent cycling of the pnuematic piston 82, the lower pusher fingers 48, 48' push the partially formed workpiece from the lower supports 44, 44' laterally and downwardly to the second work station. Again, the lower fingers remain in the extended position during the completion of the forming or impressing operation which, in the embodiment illustrated, is perfonned by rimming dies D-2, D-Z. After completion of the working operation, the

lower retractor fingers

54, 54 remove the formed workpiece out of the lower dies and discharge the same at a level below the second supports.

The arrangement of the work stations and the work feed mechanism, as above described, provides a to two-stage press in which a workpiece is sequentially fed in a cascadelike feeding movement. In the embodiment illustrated, the workpiece is advantageously a license plate on which letters and numerals are impressed or embossed at the first work station and on which the rim is impressed at the second work station. In practice, two workpieces or blanks may be fed and impressed simultaneously at each work station to provide a set of license plates. The particular arrangement of the work stations is selected for the two-stage operation and also cooperates in the feeding movement. As best seen in FIGS. 2 and 3, the upper bolster 22 carries a block 111 for compressing the book-type die D-l. To aid in insertion of the block-type die'into place, upper bolster 22 carries blocks 112 and 113 which provide an inclined face for guiding the book-type dies into place. Upper bolster 22 also has recesses I14, 114' to accommodate

pusher fingers

46, 46, respectively, in the closed or impressing position, as shown in FIG. 3. On the upper surface of intermediate bolster 26 is a die block 121, which provides a surface upon which the book-type dies may be placed. At the front of the intermediate bolster is another block 122 (See FIG. 2) rising a preselected distance above the surface of die 121 and providing a stop against which the front edge of the book die will rest. Block 122 is slotted as at 124, 124' to accommodate the lower portions of the upper pusher fingers. Block 122 may carry sensing means, hereafter described, for determining the proper positioning of the book-type dies. At the rear side of intermediate bolster 26 is an upwardly extending member 123 which provides a stop for the back side of the book-type die. Member 123 may be resiliently mounted to prevent any damage should a die not be properly positioned, or should it slip out of position. Thus, when the bolsters are in the open position, the book-type dies may be selectively inserted or removed as is required for sequentially numbering a series of license plates.

As indicated above, the second work station is between the lower bolster 24 and intermediate bolster 26. The intermediate bolster carries a block 131 on which is mounted die D-2. Block 131 extends forwardly past the front edge of intermediate bolster 26 and has an outwardly inclined face 132 and an inwardly inclined face 133. Face 132 operates as a deflector to aid in positioning the license plate or workpiece on the second support 44 and into recess 101a when retracted from the first work station. Face 133 guides the workpiece downwardly as it is moved laterally into the second work station. Intermediate bolster 26 and block 131 have slots 134, 134' to accommodate the

lower pusher fingers

48, 48, respectively, when they are in the extended position and the dies are in closed or impressing position (FIG. 3). Lower bolster 24 has a support plate 141 secured thereto and which carries mating die D-2'. A stop in the form of channel 142 is also mounted on plate 141 at the back side of die D-2' to limit the movement of the workpiece into position.

Plate 141 is provided with recesses 144, 144' to accommodate lift bars 146, 146', respectively, as best seen in FIG. 5. The lift bars extend through openings 145, 145' in the die D-2' and are provided with springs 147 (See FIGS. 2 and 3) to urge the lift bars upwardly above the surface of the die D-2'. Each lift bar is provided with a shoulder, as shown, to limit the spring-urged movement. In a similar manner, vertically movable lift bars 148, 148' are provided at the first work station (See FIG. 4) for lifting the partially formed workpiece above the lower surface of the book dies D-l. In action, after the workpieces have been suitably located at the work stations, the dies are brought down so that they strike the workpieces and perform the impressing operation. As the ram is withdrawn, the lift bar move the workpiece away from the dies so that retracting fingers may remove the same from the work stations.

The electrical control system for the apparatus of the present invention is diagrammatically illustrated in FIG. 7. As shown, supply lines L1 and L-3 each conveniently supply 220 volts therebetween and a ground line L-2. A machine motor 150 is wired to the lines L-I-L-3 as by conductors 151-153. Each conductor 151-153 is provided with a relay switch R-1 for a purpose which will hereafter become apparent. A supply line 162 and a return line 164 are connected to lines L-l and L-2, respectively. A conductor 165 extends between lines 162 and 164, and a normally open start switch 166 and a normally closed stop switch 167 are interposed in conductor 165. When the start switch is engaged, a circuit is completed from line 162 through conductor 165 and a solenoid CR-l to return line 164. The solenoid CR-l, when energized, closes the normally open relay switches R-l to energize the motor. The solenoid CR-l also closes a normally open relay switch 168 which is connected in parallel with the start switch through line 169. This operates as a holding circuit for the solenoid to maintain the same energized when the start switch is released and to continuously supply current until the stop switch 167 is depressed. An overload switch 170 is advantageously interposed in conductor 165 to stop operation in the event of an overload of current.

Another circuit includes a supply line 172 and return line 174. There is conveniently provided volts between these two lines, and they may be connected to a source in any convenient manner, for example, as by a transformer connected in the aforementioned 220-volt circuit. Before the apparatus of the present invention is operated through a cycle, certain prerequisites must be accomplished, and this second circuit is designed to assure that the cycle cannot be started until everything is ready. As 'shown, a conductor 175 extends between

lines

172 and 174, and a limit switch 176 is positioned to determine the presence of the requisite number of book-type dies D-l. Of course, there may be a limit switch for each individual dieD-l or, in the alternative, a single limit switch may be used to determine the presence of all of the required dies. When limit switch 176 is closed, this completes a circuit through line 175 and through a solenoid CR-2 interposed therein. Solenoid CR-Z closes a normally open relay switch R-2 interposed in a conductor I80 extending between lines 162 and 164. Simultaneously, solenoid CR-Z opens a normally closed relay switch 182 interposed in conductor 183 extending between

lines

172 and 174 and also opens a normally closed relay 184 interposed in conductor 185, both for purposes which will hereafter become apparent.

Before the operator at the back of the press positions his book dies D-1, he presses foot switch FS-l which is interposed in conductor 186, which also-extends between

lines

172 and 174. When the operator at the front of the press has properly positioned the license plate blank, he presses foot switch FS2 which is also interposed in conductor 186. In practice, the two operators may hold the two foot switches continuously depressed during operation. When the two foot switches have been depressed, thiscompletes a circuit through conductor 186 and a solenoid CR-3 interposed therein. Solenoid CR'-3 operates to close normally open relay switch R-3 in the aforementioned conductor 180.

An arrangement is provided to prevent recycling of the machine until at least one book-type die D-l has been removed and replaced, as is necessary in sequential numbering of license plates. For this purpose, solenoid CR-3 also closes normally open relay switch 193 in the conductor 183. Also interposed in conductor 183 is a limit switch 194 which is closed when the feed mechanism is in retracted position (See F IG. 2). Thus, when the foot switches are depressed, the feed mechanism is retracted, and at least one book-type die is removed, a circuit is completed through conductor 183 and actuates solenoid CR-4. Solenoid CR-4, when energized, closes a normally open relay switch 187 in conductor 188 which is connected inparallel with the switches 182, 193 and 194. This operates as a holding circuit for solenoid CR-4 to continuously supply current thereto until a normally closed switch 190 in conductor 188 is operated. One suitable location for switch 190 is shown in FIG. 1 where it is mounted on the housing for actuation on the upstroke of the ram 16 as by finger 191 carried by the upper bolster 22.

Cooperating with the above is a switching arrangement in the aforementioned conductor 185. As shown, a normally open switch 192 is interposed in conductor 185, and this switch is closed by solenoid CR-4. This completes a circuit through a normally closed switch R-7a and a solenoid CR-8. It will be noted that this circuit is not completed unless a book die is removed. Solenoid CR-8, when actuated, closes a relay switch R-8 in the aforementioned conductor 180, and also a relay switch R-8a in conductor 185a which provides a holding circuit until switch R-7a is actuated midway of the cycle, as hereafter described. In the manner described above, the machine cannot be recycled until at least one book die is removed and replaced.

Solenoid CR-4, when actuated, also. closes relay switch R4 in the aforementioned conductor 180. Simultaneously, solenoid CR-4, closes normally open relay switch 195 in conductor 196 and opens normally closed relay switch 197 in conductor 198. Another relay switch 199 is also interposed in conductor 196 and is operated by solenoid CR-.2.-Actuation of switches 195 and 199 completes a circuit through conductor 196 and actuates solenoid 200 which controls flow of air to the pneumatic cylinder 82 and causes the rod 84 to move toward the extended position. When the rod 84 reaches its extended position, switch 194 is again actuated as shown in FIG. 3. This operation is diagrammatically shown in FIG. 7 as another limit switch 194a interposed in conductor 202 and which operates to complete the circuit through conductor 202 and solenoid CR-S. Solenoid CR-S closes relay switch R-S in the aforementioned conductor 180. A limit switch 204 is also interposed in conductor 180 and is closed when the ram 16 is at its raised or open position. At this point, then, a circuit is completed from line 162 through conductor 180 to line 164. Completion of this circuit actuates solenoid CR-6 which closes normally open relay switches R-6. Relay switches R6 are wired in series with a main valve solenoid 210, which controls the main valve (not shown) to cause the ram 16 to move downwardly and perform the pressing operation. CR-6 also operates to actuate normally open relay 212 in conductor 213 which provides a holding circuit to maintain the current through solenoid CR-6 when the ram starts its downward movement and limit switch 204 is opened.

As the ram continues downwardly and performs the pressing operation, pressure is built up. A normally open pressure switch 214 is interposed in conductor 215 and arranged to close at a preselected pressure, thereby completing the circuit through conductor 215 and the interposed solenoid CR-7. Solenoid Cr-7 operates to open normally closed relay switches R-7 and R-7a which are interposed in conductors 180 and 185. This breaks the circuits to solenoid CR-6 and Cr-8. This, in turn, opens relay switches R-6 at the main valve solenoid and causes reversal of the main valve to raise the ram.

Adjacent the top of the stroke of the ram, the switch 190 is opened. This breaks the holding circuit to solenoid ClR-4 and operates the above-described relay switches controlled thereby. Deactuation of solenoid CR-4again closes switch 197 and completes a circuit in the conductor 198 extending between

lines

172 and 174. This actuates solenoid 224 and operates the pneumatic cylinder 82 in the opposite direction, thereby retracting the feed mechanism.

It will be noted that a power failure will deenergize solenoid (JR-4, thereby closing switch 197 which operates to retract the feed mechanism. However, solenoid 224 will also be deenergized; thus retraction can occur, and no damage will occur to the feed mechanism.

It is now deemed obvious that the complete cycle for the feeding mechanism starts with one operator loading a workpiece onto the upper support, from which point the upper pusher fingers deliver the workpiece to the book-type embossing dies which have previously been properly positioned by the second operator. Following the pressing cycle, the retracting fingers eject the partially formed workpiece and deliver it to the front of the press and onto a second lower support. A second set of pusher fingers delivers the partially formed workpiece to the rimming dies and, following a second pressing cycle, retractor fingers eject the completed plates and deliver them to the front of the press. The apparatus is equipped with sequence-type electrical controls connected to the press electric circuit in such a manner that the feed mechanism and pressing cycle are entirely automatic. The front and rear of the press are protected with solid barriers 225, 226 (see FIG. 1) so that the pressing surfaces of both the rimming and embossing stations are not accessible to the press operators.

In the manner described above, it can be seen that the device is arranged for safeness and sureness in operation. The mechanical placement of the workpieces into the dies reduces the amount of scrap generated. in addition, the automatic operation of the feed mechanism and the two-stage press increase production in work of this nature.

While the invention has been herein described as relating to license plates, it must be understood that this has been done to complete the disclosure and illustrate a useful function for the invention. While a particular embodiment of the invention has been illustrated and described, this has been done by way of iilustration and not limitation, and the invention should not be limited except as required by the scope of the appended claims.

We claim:

1. A work feed mechanism for use on a machine having a surface for e receiving a workpiece having sides, a die, and actuating means for actuating the machine to cause the die to perform an operation on the workpiece while on said surface, the mechanism comprising: support means disposed laterally from and above said surface for initially supporting the workpiece at a level above said surface; and feed means for moving the workpiece downwardly and laterally in one direction from the support means onto said surface to have an operation performed thereon, and for thereafter removing the workpiece from said surface in a direction generally opposite said one direction to a level below the support means; the feed means including first means for engaging one side of the workpiece when on said surface, second means for engaging the side of the workpiece opposite said one side when in the die, said first and second means being operatively connected, and reciprocal means for moving said first and second means in said one direction to move the workpiece adjacent the die and in said opposite direction to remove the workpiece.

2. A work feed mechanism as set forth in claim 1 wherein the die is a book-type die selectively positioned in the machine for receiving the workpiece therein; and including sensing means for determining the presence of the book-type die and preventing operation of the reciprocal means in the absence thereof.

3. A work feed mechanism as set forth in claim 1 including control means for controlling the actuating means and the reciprocal means to move the first and second means in said one direction prior to actuation of the machine to cause the die to perform said operation and in said opposite direction after said die operation, said control means being operative to hold the first and second means generally stationary while the die performs said operation.

4. A work feed mechanism as set forth in claim 3 wherein the die is selectively positioned in the machine, and the control means includes sensing means for determining the presence of the die and preventing operation in the absence of the die.

5. A work feed mechanism as set forth in claim 4 wherein the die is a book-type die easily positioned and removable from the machine, and wherein the control means operates through a cycle to allow removal of the book-type die and positioning of another die prior to a succeeding cycle.

6. A work feed mechanism for use on a machine having a surface for receiving a workpiece, and means for performing an operation on the workpiece while on said surface, the mechanism comprising: first support means disposed laterally from said surface for initially supporting the workpiece at a level at least as high as said surface; second support means disposed below the first support means and at a level below said surface for receiving the workpiece therefrom; and feed means for moving the workpiece in one direction from the first support means onto said surface to have an operation performed thereon, and for thereafter removing the workpiece from the surface downwardly and laterally to the second support means in a direction generally opposite said one direction; the feed means including extending finger means for moving the workpiece in said one direction; retracting finger means for removing the workpiece from the surface in said opposite direction; means operatively connecting said finger means so that they move in unison; and reciprocal means for moving the finger means in unison to push the workpiece onto said surface, and for retracting the finger means in unison to remove the workpiece after the operation is performed.

7. A work feed mechanism as set forth in claim 6 wherein the machine includes a second surface at a level below the first-mentioned surface and no higher than the level of the second support means, and means for performing another operation on another workpiece on the second surface; and wherein the feed means is operative for moving a workpiece from the second support means onto the second surface to have said other operation performed thereon, and for removing said workpiece from the surface; whereby a workpiece is moved sequentially from the first support means to the firstmentioned surface, therefrom to the second support means, therefrom to the second surface, and finally removed therefrom. I

8. In combination, first and second work mechanisms for each performing an operation on a workpiece having sides; means for supporting the first work mechanism at a level above the second work mechanism; a first support adjacent the first work mechanism for initially supporting the workpiece at a level above the first work mechanism; a second support adjacent said work mechanisms and at a lever therebetween; feed means for moving one workpiece from the first support downwardly to the first work mechanism and concomitantly moving another workpiece from the second support downwardly to the second work mechanism; said feed means being operative for removing said one workpiece from the first work mechanism downwardly to the second support and concomitantly removing the other workpiece from the second work mechanism; the feed means including first and second portions each associated with one of said supports, each portion including first means for. engaging one side of the workpiece on the respective support and second means for engaging the opposite side of the workpiece in the work mechanism, each first and second means being operatively connected and the first and second portions being operatively connected; and the feed means also including reciprocal means for moving the first and second portions and thereby moving the workpieces.

9. The combination as set forth in claim 8 wherein the first work mechanism is generally vertically above the second work mechanism, the first support is generally vertically above the second support, said supports are disposed laterally from the work mechanisms, and the feed means moves said one and other workpieces laterally in one direction to the work mechanisms and removes said workpieces laterally in a direction generally opposite said one direction.

10. The combination as set forth in claim 8 wherein each work mechanism includes a die; and including actuating means for concomitantly actuating said dies to perform said operations; and control means for controlling the actuating means and the reciprocal means to move the workpieces to the dies prior to actuation thereof and to remove the workpieces after the operation by the dies.

11. The combination as set forth in claim 10 wherein the die at one of said work mechanisms comprises a book-type die selectively positioned at the work mechanism for receiving a workpiece therein; and wherein the control means includes sensing means for determining the presence of the book-type die and preventing operation of the reciprocal means in the absence thereof.

12. The combination as set forth in'claim 11 wherein: the

first work mechanism is generally vertically above the second work mechanism; the first support is generally vertically above the second support, said supports are disposed laterally from the work mechanisms; and the feed means moves said one and therewith define the first work mechanism, another die is positioned between the second and intermediate bolsters and therewith define the second work mechanism, the actuating means is operative for moving the ram toward and away from the bed, and the resilient means being operative for holding the intermediate bolster in position spaced from the second bolster until force sufficient to overcome the resilient means is transmitted from the ram and first bolster to the intermediate bolster.

14. The combination as set forth in claim 13 wherein the workpiece is a license plate; the book-type die is shaped to impress an indicium on the license plate; the book-type die being readily removable when the ram is at an open position for insertion of a different book-type die so successive plates can be impressed with sequential indicia; and the control means con trols the actuating means through a cycle for moving the ram from the open position to an impressing position and back to open position, and for stopping the ram at the open position to allow changing of the book-type die.

15. In a reciprocating press having a ram and a bed, the combination of: a first bolster for engagement by the ram; :1 second bolster carried by the bed; an intermediate bolster positioned between the first and second bolsters; means for moving the ram through a cycle first toward and then away from the bed; said first bolster being engaged by the ram and moved toward the intermediate bolster, and the intermediate bolster being moved toward the second bolster as the ram is moved toward the bed; first die means positioned between the first and intermediate bolsters for performing an operation on one workpiece when the is moved toward the bed; second the means positioned between the second and intermediate bolsters for performing another operation on another workpiece when the ram is moved toward the bed; and feed means for moving a workpiece to a position to be operated upon by one of said die means and for transferring the workpiece therefrom to a position to be operated upon by the other of said die means.

16. The combination as set forth in claim 15 including means for resiliently urging the intermediate bolster a preselected distance away from one of said first and second 7 bolsters so that initial movement of the ram causes relative movement between the intermediate bolster and the other of said first and second bolsters.

17. The combination as set forth in claim 15 including a first support disposed laterally of the first die means for supporting a workpiece for feeding into the first die means, a second support disposed below the first support for receiving a workpiece from the first die means and for supporting the same for subsequent feeding into the second die means, and means mounting at least a portion of the feed means for movement with the intermediate bolster.

Claims

7. A work feed mechanism as set forth in claim 6 wherein the machine includes a second surface at a level below the first-mentioned surface and no higher than the level of the second support means, and means for performing another operation on another workpiece on the second surface; and wherein the feed means is operative for moving a workpiece from the second support means onto the second surface to have said other operation performed thereon, and for removing said workpiece from the surface; whereby a workpiece is moved sequentially from the first support means to the first-mentioned surface, therefrom to the second support means, therefrom to the second surface, and finally removed therefrom.

8. In combination, first and second work mechanisms for each performing an operation on a workpiece having sides; means for supporting the first work mechanism at a level above the second work mechanism; a first support adjacent the first work mechanism for initially supporTing the workpiece at a level above the first work mechanism; a second support adjacent said work mechanisms and at a lever therebetween; feed means for moving one workpiece from the first support downwardly to the first work mechanism and concomitantly moving another workpiece from the second support downwardly to the second work mechanism; said feed means being operative for removing said one workpiece from the first work mechanism downwardly to the second support and concomitantly removing the other workpiece from the second work mechanism; the feed means including first and second portions each associated with one of said supports, each portion including first means for engaging one side of the workpiece on the respective support and second means for engaging the opposite side of the workpiece in the work mechanism, each first and second means being operatively connected and the first and second portions being operatively connected; and the feed means also including reciprocal means for moving the first and second portions and thereby moving the workpieces.

12. The combination as set forth in claim 11 wherein: the first work mechanism is generally vertically above the second work mechanism; the first support is generally vertically above the second support, said supports are disposed laterally from the work mechanisms; and the feed means moves said one and other workpieces laterally in one direction and removes the workpieces laterally in a direction opposite said one direction.

13. The combination as set forth in claim 12 including a reciprocating press having a ram and a bed, a first bolster carried by the ram, a second bolster carried by the bed, an intermediate bolster positioned between the first and second bolsters, and resilient means for resiliently urging the intermediate bolster a preselected distance spaced from the second bolster; and wherein said book-type die is selectively positioned between the first and intermediate bolsters and therewith define the first work mechanism, another die is positioned between the second and intermediate bolsters and therewith define the second work mechanism, the actuating means is operative for moving the ram toward and away from the bed, and the resilient means being operative for holding the intermediate bolster in position spaced from the second bolster until force sufficient to overcome the resilient means is transmitted from the ram and first bolster to the intermediate bolster.

14. The combination as set forth in claim 13 wherein the workpiece is a license plate; the book-type die is shaped to impress an indicium on the license plate; the book-type die being readily removable when the ram is at an open position for insertion of a different book-type die so successive plates can be impressed with sequentIal indicia; and the control means controls the actuating means through a cycle for moving the ram from the open position to an impressing position and back to open position, and for stopping the ram at the open position to allow changing of the book-type die.

15. In a reciprocating press having a ram and a bed, the combination of: a first bolster for engagement by the ram; a second bolster carried by the bed; an intermediate bolster positioned between the first and second bolsters; means for moving the ram through a cycle first toward and then away from the bed; said first bolster being engaged by the ram and moved toward the intermediate bolster, and the intermediate bolster being moved toward the second bolster as the ram is moved toward the bed; first die means positioned between the first and intermediate bolsters for performing an operation on one workpiece when the is moved toward the bed; second die means positioned between the second and intermediate bolsters for performing another operation on another workpiece when the ram is moved toward the bed; and feed means for moving a workpiece to a position to be operated upon by one of said die means and for transferring the workpiece therefrom to a position to be operated upon by the other of said die means.

16. The combination as set forth in claim 15 including means for resiliently urging the intermediate bolster a preselected distance away from one of said first and second bolsters so that initial movement of the ram causes relative movement between the intermediate bolster and the other of said first and second bolsters.