US2348439A - Press and the like - Google Patents

Description

May 9, 1944- y v. wQPx-:TERsoN ETAL. 2,348,439

PRESS AND4 THE LIKE origina; Filed octfzz, 1957 ssheets-sneet 1 May 9 1944 v. w. PETERSON ET AL 2,348,439

PRESSAND THE LIKE origina; Filed oct. 22, 1957 5 `Sheets-Sheet `2 May 9, 1944- v. w. PETERSON ET'AL 2,348,439

' `PRESS AND THE LIKE l original Filed oct. 22. les? s sheets-sheet s Patented May 9, 1944 PRESS AND THE LIKE Victor W. Peterson and Otto J. Maha, Chicago, Ill., assignors to Hannn Manufacturing Co., Chicago, lll., a corporation of Illinois Original application October 22, 1937, Serial No.

170,407, now Patent No. 2,308,712, dated January 19, 1943. Divided and this application January 26, 1942, Serial No. 428,252 v tool quickly on the work. Thereafter intensied 4 Claims.

This invention relates to riveting and other presses, among other objects aims to provide improved vcontrol means for multiple press units.

The invention may be readily understood by one illustrative apparatus embodying the invention and shown in the accompanying drawings.

vIn said drawings:

Fig. 1 is a view in the form of a diagrammatic section illustrating the apparatus;

Fig. 2 is an elevation, partly in section,'of a Patent-,.No. 2,308,712, wherein an improved unit for supplying power to a press is disclosed and claimed. The present application relates to the control of multiple press units. Where a plurality of press units are operated successively, that is, not simultaneously, from a single power unit, it is important that operation of idle press units be prevented without, however, interfering with or delaying the operation of a given press unit when its use is needed. This prevents injury of workmen and waste of power.

One form of power unit, that disclosed in the aforesaid co-pending application, is diagrammatically illustrated in Fig. 1 and will rstbe briey described.- An earlier form of said power unit is disclosed in our Patent No. 2,241,645. For a more complete description of the structure and operation of said unit reference is made to said patent and said co-pending application.

The power unit is here shown operating a riveting press I0, but it will be understood that the press unit may be a punch or other instrumentality connectedY either by exible or rigid lines with the power unit. The illustrative riveting press comprises an operating piston I I,.` cylinder I2, and a riveting tool or plunger I3. The riveter is connected to the power unit I4 through exible lines I5 and I6, the former transmitting uid for thev advance or power stroke and the latter for the return stroke.

To secure rapid advance of the tool or plunger into operative engagement with the work, fluid is supplied'to the head end of the cylinder' in large `volumes at relatively low pressures up to approximately onethousand` (.1000) pounds per pressures up to about five thousand (5000) pounds per square inch are applied to complete the operation.

The primary uid pressure is supplied in this instance by rotary vane pump I1 driven by an electric motor lil. The pump inlet is-immersed `in a reservoir of oil in the case I9 of the apparatus, the oil entering the pump through inlet pipe 20 and being discharged therefrom through pipe 2|. Except for periods when the pressure is actually in operation, fluid delivered by the pump is short circuited or returned to the reservoir at practically zero pressure, the motor operating at practically no load.

For the nal or high pressure operation, the fluid pressure delivered to the work cylinder is intensified by an intensifier 23 represented by small and large pistons 24 and 25, the pump supplying pressure through pipe 25 to the face of the large piston 24 which has four to ve times the area of the small piston. `The volume oi the high pressure intensifier cylinder `2'I is made suicient not only to complete the work stroke of the press, but to compensate for the stretching or expansion of the apparatus and hose lines under the very high pressure which is developed.

The return stroke of the work piston is controlled by pressure-responsive device 28 (Fig. 1) which operates to direct the pump pressure through pipe 29 and return line I6 to the opposite 0r return face of the work piston and to open the head end of the cylinder I2 and the intensier to discharge. The return stroke is under 1 control of a pressure-responsive device 30 which operates when a predetermined pump pressure is reached to eect neutralization of the system by connecting both the pump and the return line 29 with discharge, thereby dropping the pump pressure to substantially zero and relieving the load on the motor.

The pump is connected through pipe 2| and passage 3| in valve block 32 with a main or primary valve 33. which controls the forward and return stroke of the piston and terminates movement of the piston at any point in the cycle. In

this instance, the valvelcomprises a double spool or piston valve controlling passages 34 and 35 leading to exhaust, a passage 36 leading to the power side of the work cylinder, and the passage 3l leading to the return side of the work piston. Valve v33 is illustrated in full lines in its neutral or short circuited position, in dotted lines 39 in its lower position wherein the pump is connected square inch. These are suiiicient to close the With the passage 35. and dotted lines 40 in its upper position wherein the pump is connected to the reverse passage 31, the passage 85 ,being connected to discharge through passage 34.

If it be desired for any reason, the forward stroke of the work piston may be arrested and reversed at any time. This operation is eected 4by relatively shifting the fulcrum points of the floating lever 46 which connects the primary valve stem 41'with the solenoid armature 48. The solenoid is energized by a control switch such as a push button 50 at the end of the operating handle 5| on theriveter. The lines 52 lead from the push button to -a relay for controlling the solenoid 45. When armature 48 is actuated, lever 46 operates through its vfulcrum 53 to depress the primary valve to position 39.

` To elect movement of the valve to reverse position (i. e., position 46) the returning spring 54 is automatically pre-compressed to a degree greater than that for holding it in the neutral position illustrated in full lines in Fig. 1 by means in the form of acooking pin 55. The latter is elevated by secondary lever 56 connected with both valve stem 41 and the cooking pin and fulcrumed Vat an intermediate point 51. The lever is notched at 58 to provide a seat for the fulcrum so that the lever may be elevated clear of the fulcrum upon the upward movement of the primary valve to reverse position. The cooking pin is held in its cocked or its spring-compressing postion -by a latch 59 controlled by the pressure-responsive device-30 which is actuated upon a predetermined baok pressure to permit the latch and withdraw the cooking pin .to return to its unlatched position (that in Fig. l) to restore the pin 55 to the'normal-condition necessary for a returnof the primary valve to neutral position at the end of the cycle of operations. Cooking pin v55 carries an arm 60 uponwhich the end of the spring 54 seats` and 1' by which the spring is additionally pre-compressed upon elevation of the cooking pin.- The latter isV returned to its uncooked position by Spring 6|.

The pressure-responsive device 30 comprises a plunger 62, connected through passage 63 with the vreturn vpressureline'l, which is held down by a pre-loaded spring '54 until a predetermined back pressure has been reached. The loading of spring 64 may be adjusted by [key 65 or in any other appropriate'manner. Latch 59' is pressed toward the cooking pin by spring 65 and is withdrawn therefrom upon actuation of pressure-responsive device 30 by the cam surface 61 which engages the opposite end of latch 59.

If solenoid 45 be deenergized at any point in the Vforward stroke'of the Work piston, spring 54 (having been additionally loaded by the cocking pin) will elevate the primary valve to its return position 4|) (lifting lever 56 clear of its fulcrum 51); Such return position ismaintained until either the solenoid be reenergized or until the 'cooking pin be released. l

i Control of the operation of the intensifier is effected by pressure-responsive valve 16 which connects pumpr pressure with the intensier pasvsage 26 and `'whichfis exposed to pump pressure from passage 1|, whose orice registers with a small bore l2 inside the valve. The lower portion of the bore is closed by pin 13. The intensier valve is controlled by a pre-loaded spring 14 to which pressure is communicated by an intervening plunger 15 which acts on the iluid confined vin valve chamber 16V. Raising of valve 10 at a predetermined'pressure connects passages 36 and 25 by means of passage 11 around the valve. At the same time the lower end 18 of the valve cuts off discharge passage 19. As the intensier operates the end 8| of the plunger 24 cuts oi passage 82 connected with the passage 36 by the annular passage 83 around the intensifier valve. To prevent chattering of the intensifier valve, the uid displaced from chamber 16 passes through valve 85 (controlled by preloaded spring 14) through pipe 86 to discharge. The intensier valve, therefore, cannot be returned to initial position upon the drop in pump pressure which ensues upon initial operation of the intensiier. The loading on spring 14 is adjusted by screw plug 81.

The return cycle commences when the intensifier pressure communicated through line 9| to plunger 92 is great enough to compress spring 93 and Withdraw latch 96 to release fulcrum pin 95 and to permit shifting of the primary valve to reverseV position. In the latter position pump pressure is delivered through lines 63 and 86 past check valve 88 to return the intensier valve to initial position. Latch 96 is pressed toward the fulcrum pin by spring |0| and when it engages the shoulder S9 serves to hold the fulcrum pin in lowered position.

Resistance to further movement of the work piston at the end of the return stroke causes a rise in pump pressure Ato a predetermined level sulcient to raise plunger 62 and release the cooking pin 55, thereby allowing the primary valve to return to neutral position. On release of the push button by the operator, solenoid 45 is de-energized thereby allowing the fulcrum pin to return to its lower position where -it is held by latch 96, plunger S2 having in the meanwhile been lowered by the fall of the pressure inthe intensifier cylinder. A new cycle may be started at any point in the return stroke of the work piston simply by pressing the push button 50. y

A safety valve |03 protects the pump against excessive pump pressure by opening the line to discharge through passages |04 and |05 if the pump pressure rises to a value suiciently to compress the pre-loaded spring |06. To prevent development of excessive back pressure and excessive oil velocity, the intensifier cylinder 23 is provided with a substantially large port |01 oontrolled by a dump valve |08 in the form of a spool valve |09, toallow direct discharge of the substantial volume of oil in cylinder 23 without the necessity for returning through line 26 whence it came. The dump valve is opened by the develipment of pressure in return line 31 to which the valve cylinder ||2 is connected by line Oiil passes easily and at relatively low velocities through port |01, valve |08 and discharge opening 3. The dump valve is returned to closed position as soon as pressure for the forward stroke of the work piston develops in line 36 with which the valve cylinder is connected through line H4.

YMore than one press unit may be operated from a single power unit provided the press units operate eitherk simultaneously or successively. For example, a single operator may require two or more riveting yokes, one yoke being specially designed to reach rivets which cannot be set by a standard yoke. Since only one riveter is opdeliberate operation `of any other riveter' con-I switches |45 and |46 controlled by the low volt- -age circuits are employed to deliver normal line Avoltage to the operating solenoids.

nected to the same unit, while the first-named riveter is thus connected. The apparatus is here "shown provided with such a controlling device ywhich may advantageously be in'the form of a shuttle valve H (see Figs. l to 4) which operates to connect the pressure fluid delivered from the unit through the pipe HB with the unit in use. y i

vAs shownin Fig. 4, the high pressure `lines |1 and I I8 from the respective work cylinders com- -municate with the shuttle valve cylinder l||9 through ports |2| and |22. The shuttle valve is in Vthe present instance in the form of a balanced spool valve 'which is adapted toconnect the pressure liuid delivered'through port |23 with either port |2| or |22 depending upon the'position ofthe shuttle valve. The return lines .|24 and |25 from the respective work cylinders are connected through passages |26 and |21 inthe shuttlevalve block with the return line 29. In-

asmuch as the high pressure line is under selective control, it is unnecessary to control the return lines. They may be in communication at all times with return line 29. When pressure develops in the latter line, it simply is applied as static pressure to any inactive work cylinder. A drain pipe |23 is connected with ports |29 in the shuttle valve cylinder at points beyond the shuttle valve to drain away any fluid which may leak past the ends of the shuttle valve and return the same to reservoir I9.

The shuttle valve is in this instance operated by solenoids |3| and |32 connected, as presently explained, in circuits controlled by the control switches on the respective press units. The solenoid armatures or cores operate the shuttle valve yokes |33 connected with the projecting shuttle valve rods |34. Energization of one solenoid shifts the valve to one position where it remains until the first solenoid is deenergized and the other is energized to reverse the position of the valve. Mere energizaticn of the other solenoid is not sufficient to effect shifting since its initial power, because of the greater magnetic air gap, is not great enough to overcome that of the rst solenoid which, in its closed position wherein the magnetic air gap is relatively small, develops substantially more power than the other develops in its open position. In the present arrangement the energization of the Ina-in solenoid 451s made impossible until the shuttle valve has been shifted to one operative position. A circuit through the main solenoid 55 cannot be closed while the shuttle valve is in intermediate position. For this purpose` the control mechanism is provided with a switch |35 advantageously in the form of a double pole switch of conventional design which in both its upper and lower positions closes a circuit through the main solenoid 45. The aforesaid switch is here shown operated by a cam |3E carried by yoke |33 (see Fig. 2) which in one position depresses the switch plunger |31 to close one pair of contacts |39 and in the extreme position allows the aforesaid plunger to rise to connect the other pair of contacts |38. The switch spring I4| is arranged to press the plunger |31 upwardly when cam |35 clears the plunger roller |42.

Fig. 5 illustrates one appropriate circuit arrangement. Preferably a transformer |43 is employed to step down the voltage of supply lines |44 to impose only a relatively low voltage on the lines leading to the push button switches 5|) on the respective press units (in this instance designated #l and #2), and double pole relay 75 Thus when the circuit is closed in #2 press unit, the relay coil |41 controlling relay contactor |45 is energized, thereby closing the circuit through shuttle valve solenoid |3| shifting the solenoid tothe position illustrated in Fig. 2 and closing thecircuit through the poweroperating solenoid 45. 4It willbe noted that the operating solenoid 45 is in circuit both with the switch |35 andwith the respective relays and |45 .and requires the closingof switch |35 and one of the relays in order to establish a circuit which would energize` the operating solenoid 45. VThus if the push button Vcircuit be opened at any time during the cycle of operation, its relay `switch |45 would open, thereby. de-energizing solenoid 45 and making possible the same control of the press piston as above described in connection with the operation of a single press unit.

Upon de-energization of one shuttle valve solenoid, the other may be energized to shift the valve to connect its press with the power unit. Accidental operation of any idle press is impossible.

More than two press units may be operated by a single power unit by duplicating the shuttle valve and its controlling apparatus, that is, by connecting other shuttle valves with the high pressure outlets |1 and ||8 leading from the preceding shuttle valve and connecting a pair of press units to each of the former shuttle valves.

Obviously the invention is not limited to the details of the illustrative construction since these may be variously modified. Moreover it is not indispensable that all features be used conjointly since various features may be used to advantage in different combinations and sub-combinations.

Having described our invention, we claim:

1. In apparatus of the character described, the combination of a plurality of fluid operated Dresses adapted to be selectively separately operated, a single power unit for supplying uid pressure to each of said presses, fluid lines leading from said power unit to each of said presses, control mechanism for selectively connecting said power unit with a single selected press and for disconnecting said power unit from all other presses, a plurality of control devices one associated with each of said presses for actuating the control mechanism to connect the power unit with the press whose control device is operated and to disconnect said power unit fromall other presses as aforesaid.

2. In apparatus of the character described, the combination of a plurality of fluid operated presses adapted to be selectively separately operated, a single power unit for supplying uid pressure to each of said presses, fluid lines leading from said power unit to each of said presses, control mechanism for selectively connecting said power unit with a single selected press and for disconnecting said power unit from all other presses, a plurality of control devices one associated with each of said presses for actuating the control mechanism to connect the power unit with the press whose control device is operated and to disconnect said power unit from all other presses as aforesaid, said control mechanism having means for rendering the control devices on said other presses ineffective during the work stroke of the selected press.

y 3. In apparatus of the character described, the combination of a plurality of iluid operated presses adapted to be selectively separately operated, a single power unit for supplying fluid pressurel to each of said presses, and including a pump and main valve normally in neutral position to permit said pump to idle, uid lines leading from saidpower unit to each of said presses, selector means for connecting said power unit with one of said presses and for simultaneously disconnecting itfrom all other presses, a plurality of control devices Yone associated with each of said presses for actuating said main valve and said selector means to direct vpressure uid to the press whose control device was actuated and to cut offisupply from all other presses, and means associated withvsaid control devices for rendering the control devices on all said other presses ineffective during the Work stroke ofthe selected press.

4. In apparatus of the character described the combination of a plurality of iluid operated presses adapted to be selectively operated and including a pump and main valve normally in neutrol position to permit said pump to idle, forward and return lines leading from said power unit to each of said presses, selector means for connecting said power unit with the forward line of the selected press and for disconnecting the forward lines of all other presses, the return lines of all other said presses being connected at al1 times with said power unit, a plurality of control devices one associated with each of said presses for Aactuating said main valve and said selector means to direct pressure fluid to the press whose control device was actuated and to cut ol supply from all other presses, and means associated with said control devices for rendering the control devices on all said other presses ineffective during the work stroke of the selected press.

VICTOR W. PETERSON.

OTTO J. MAHA.

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