US1880874A - Press - Google Patents

Description

oct. 4, 1932, J, DEJRRY 1,880,874

PRESS Filed April l1. 1930 3 .Sheets-Shes?I l INvN-I-EIR:

' @CL 4s i932. J, BERRY 1,8874

PRESS Filed April 11. 195o 3 sheets-sheet 2 INvEN-l-DR:

0t.4, 1932. J, BERRY 1,880,874 l PREss` l Filed April 11, 1950 3 Sheets-Sheet 5 EYWMNL Patented Oct. 4, 1932 PATENT-i :t

JASPER DERBY, on MEDFORD, MASSACHUSETTS, AssIGNon To ANDREW TnnknnsnN, or NEWTON, MASSACHUSETTS PRESS Application led .April 11, 1930. Serial N'o. 443,390.

.This invention relates to presses and is inV press wherein the closing movement of the press elements is automatically controlled and limited by the pressure exerted upon the work irrespective of the size and character of the latter, and wherein said pressure is maintained after the stopping of the press, noty withstanding subsequent volumetric changes in the work, to provide means for automatically stopping the opening movement of the press elements .whenthey have been separated by a predetermined Vbut 'variable amount, to provide means whereby the pre. determined pressure exerted upon the work can be conveniently adjusted and varied in accordance with the requirements, and to pro- Vvide means whereby the operation ofk the press can be manually,as well as automatically, controlled. y

More particular objects of the present invention are to provideanelectrical control for presses of this type, thereby greatly simplifying the mechanism, and to provide means for automatically stopping the movement of the-movable press element toward the cooperating element upon failure, for any reason, of said cooperating element to eXert its normal reaction to the pressure exerted by said movable element. Y

The foregoing and other objects of the invention, together with means whereby the latter may be carried into eiect, will best be understood from the following description of a preferred embodiment thereof illustrated in the accompanying drawings, but it will also be understood that the particularconstruct-ion and adaptation described and shown have been chosen for purposes of exemplification merely, and that the invention, as defined by the claims hereunto appended, may be otherwise embodied'without `departure from the. spirit and scope thereof.

In said drawings:

Fig-1 is a front elevation of a press em-l bodying the invention, f

F ig. 2is a horizontal section taken substantially on the line 2-,-2 of Fig. 1,

Fig'. 8 is awiring diagram of the electrical connections, A

F ig. 4 is a detail,verticalsectional view of the electromagnetic reversing switch.

Fig. 5 is a detail view of the solenoid brake.

Referring particularly to Figs. 1 and 2the relatively movable press elements comprise a bed l5 and a ram 16 which may carry suitable complementary dies 17 or other devices in accordance withY the nature ofthe work to be performed by the press. The bed'15 is supported by fourparallel, upright posts or rods 18 to which it is secured in any suitable manner, as by means of nuts 19 engaging threaded end portions 19a on said posts. A The posts lor rods 18 'are guided for ver tical longitudinal movement in suitable bearings 20 and'21 in the frame 14, the latter being` adapted -to receive the reduced portions 10 at the lower ends of said posts and constituting abutments upon which said posts normallyV rest.

Surroundingthe postsor rods 18 below the bearings 2O are heavy coil springs 22 interposed between ianges 23 formed on the frame and collars 24 -in engagement with the threaded lower ends 25 of said posts and secured Yin adjusted position thereon by set screws 12. The collars 24 cooperate with the rods 18 whereby the springs 22 may be placed and held under a predetermined initial compression. l `With this arrangement ity will be seen vthat when the press elements approach one another, so asto'engage the work therebetween at opposite sides, the pressure of the ram against the vwork and bed.`

will be transmitted to the springs`22 which willyield to permit movement of the bed and displacement of the posts to an extent determined by the pressure applied and consequent compression of the springs.

The ram 16is carried by a'double rack 27 guided in the frame 14 and engaged Aat opposite sides by two pairs of pinio'nsl 28 100 fast on parallel shafts 29 journalled in the frame and also having fast thereon intermeshing gears 30 connecting the pinions of each pair. One gear 30 of each pair of pinions meshes with a pinion 31 fast on a shaft 32 journalled in the frame and having fast thereon a gear 33. The gear 33-meshes with a pinion 34 fast on a shaft 35 journalled in the frame and having fast thereon a gear 36. The gear 36 meshes with a pinion 37 fast on a shaft 38 which is journalled in a gear casing 39 carried by the frame. The

shaft 38 has fast thereon a worm gear 4.0V

which meshes with a worm'l on the *arma` ture shaft 4t2 of an electric motor M suitably supported on the frame, said shaft 42 being likewise journalled in the gear casing 39.

The motor M, which ispreferably an alternating current motor of the three-phase type, is supplied 'with electrical energy from three feed lines L1,.L, and L3. (SeeFig. 3.)Y In accordance with the invention, the operation ofthe motor is controlledto move the ram 16=in one direction to exert the predetermined' pressure upon the work and in a reverse direction to release the pressure and separate thel press elements.. For this pur# pose the passage of the current through the feed lines vto the vmotor is controlled by a magnetic reversing switch R'which throws the motor across the line.` l

The reversing switch R'(see Figs. 3 and 1)v is provided with two triplepole, mag-` netically-operated contactors a and b' which are wired as shown in Fig. 3.so that whenV one contactor is closed the motor operates in one direction and when the other contactorisY closed the motor operates in-the reverse direction.l Each contactor. is closed by an operating coil 61v or 71 which is controlled by a separate circuit connected with the feed lines, both circuits lbeing controlled by a manually operated, three-button control station C having an up switch 80, a down switch 81and a stop switch 82. The up and down switches are of the momentary contact: type, being normally open while the stop switch is normally closed. lEach circuit is further controlled bya limit switch A or B- which is operated automatically to stop the motor and thus limit the movement ofthe ram in eitherdirection. The limit switches are normally closed. y

The contactor-a (seewparticularly Figa) comprises lfixed and movable members, the latter beingpivotally mounted on the frame .112 ofthe reversing switch,fand being provided with anarmature which cooperates with the coil 61 when the latter is energized to close said contactor. An .electricinterlock e, operated Vby the contactora and'provided for the purpose of'closing: its operating circuit, comprisesa movable member 111 yieldlnglymounted A1n the movable member 'G5 of said contactor and fixedmembers 113. se-

cured to the frame 112. The contactor b likewise comprises fixed and movable vmembers, the latter being pivotally mounted on the frame 112 and being provided with an armature 114 which cooperates with the coil 71 when the latter is energized to close said contactor. An electric interlock y operated by the contactor b and provided for the purpose of closing itsopera-ting circuit comprises ammovable member- 11'5 yieldingly mounted in the movable member of said contactor and Xed members 116 secured to the frame 112. The contactors are mechanically interlocked by a bar 117 pivoted intermediate its ends to the frame 112, said ends beingV secured by links 118 to each of the Vmovable members ofsaid contactors. This. construction Aprevents both contactors being closed atthe same time. The contactors and the electric. interlocks are normally open,

but when either contactor is closedlthe interlock forV completing its operating circuit is also closed whiletheother interlock is open, v

the closing ofl only vone cir#` A,wire 65, s top7 switch .82, wires 66and l" 67, and out through line L3.

Thiscauses the operating coil 61 Vto-.be energized and the contactor a to be closed, which connects theV feed lines L1, L2 and-La with the motor as shown in Fig. 3, to drive it in a direction to move the ram 16 forwardly, or upwardly, towards the bed of the press. As this contactor is closed, its inter-- lock c is closed, andthe current may now flow through line L2, wire 60, coil 61, wire 62, interlock e, wires. 68 and 64, limit switch A, wirev65, stop switch 82,7wires 66 and 67 and line La, or it-may flow through line Ll, wire 69, interlock e,'wire62, coil 61, wire 60 and line L2 depending'upon the Vpolarity ofthe feed lines. c *y Ilhe circuitjust described keeps the oper# ating coil 61 energized regardless of the polarity ofv the feed lines and thus insures an uninterrupted movementfof thevpress ram in .a forwarder upward direction until the limit switch'rA is automatically opened or the stop switch 82 is previously lopened by the operator in case of an emergency.

When a predetermined pressure between the press elements has been reached and 'the limit switch A automatically Vopened,*as hereinafter explained, the contactors-will assume an opened position and, as was previously stated, both interlocks e and.;e will be opened. `To release the pressure andseparate the press elements, the operator presses the button to momentarily close the down switch 81. This closes a circuit indicated in light dot and dash lines in Fig. 3 for controlling the reversing switch B. to operate the motor in a reverse direction for the above purpose. At this time the current will flow, through line L2, wires 60 and 70, operating coil 71, wires 72 and 73, down switch 81, wire 74, limit switch B, wire 75, stop switch 82 and to the line L3 through the wires 66 and 67 which are common to both operating circuits. Y

The operating coil 71 thus energized closes the contactor b which connects the feed lines with the motor to throw the latter across the line and thus reverse it. As this contactor is closed, its interlock f is closed, and the current may now ilow through line L2, wires 60 and 70, coil 71, wire 72, interlock f, wires 78 and 74, limit switch B, wire 75, stop switch 82, wires 66 and V67 and line L3, or it may flow through line L1, wires 76 and 77, interlock f, Wire 72, coil 71, wires 70 and 60 and line L2, depending upon the polarity of the feed lines. The circuit just described keeps the operating coil 71 energized regardless of the polarity of the feed linesand thus insures an uninterrupted movement of the press ram in a reverse direction until stopped by the automatic opening of the limit switch B or the manual opening of the stop switch 82.

It will be understood that the up switch 8O and down switchV 81 are manually operated to start the press in accordance with the requirements, and that the stop switch 82 may also be manually operated to stop the press at any time in case of emergency. The limit switches A and B are automatically operated by the moving parts of the press and to this end each is provided with an operating or trip arm 26 each of which normally occupies a position to close its respective switch but which is capable of operation to open said switch.V The trip arm 26 of the limit switchB is disposed in the path of movement of a lug 43 adjustably secured, as by a set screw 44, to a rod 45 projecting upwardly from the ram 16, said trip arm being engaged by said lug to open the limit switch B when the ram 16 has descended to its lowermost position determined by the adjusted position of said lug on the `rod 45. The trip arm 26 ofthe limit switch A is disposed in the path of movement of a projection 46 on a slide 47 Vheld in a clamp 48 carried by one of the posts 18 and is engaged by said projection to open the limit switch A when said post moves upwardly under the yielding action of the springs 22. The slide l47 is adjust-- ably carried by the clamp l48 and is preferably provided with a suitable scale 49, whereby the extent .of yielding movement of the springs 22, and consequently the pressure upon the work, necessary to open the limit switch A may be conveniently varied. The trip arm 26 of the limit switch A is alsoV operable to open said switch by a slide 50 vertically movable in guides 51 on an upright frame member 52 which supports the hand control and limit switches, said slide 50 having an angular upper end 53 disposed in the path of movement of thelug 43 and adapted to be engaged thereby upon excessive upward movement of the ram 16.

The operation is as follows:

InV Fig. 1 the ram 16 is shown in a midposition in its path of travel. Assuming that the ram is moving upwardly at this time, this movement will be continued untilthe dies 17 have closed upon the work and have Y exerted thereon a pressure sufiicient to cause the springs 22 to yield and the posts 18 to move upwardly. movement, and consequently of the pressure 'exerted upon the work, as predetermined by the adjustment of the slide 49 in the clamp 48, has been reached, the projection 461engages the trip arm 26 of the limit switch A, thereby opening said switch and stopping the When the limit of this movement of the ram. The work is there- Y upon resiliently held under the predetermined pressure by the springs 22 which, in case of any shrinkage of the work, can' expand slightly to exert a follow-up pressure f thereon. To lrelease the pressure and sepavrate the press elements, the down, switch 81 is momentarily closed, thereby reversing the motor M as above described. The ram 16 is thereupon moved downwardly until'v the lug 43 engages the trip arm 26 of the limit switch B, opening the latter switch and again stopping the motor M andthe movement of the ram.

In the event of breakage of the springs 22, or stripping of the threads .on` the upper ends 19a of the posts 18, or the failure of the nuts 19, or other condition preventing the bed 15 from exerting its normal reaction to the upward pressure of the ram, the vconsecpient abnormal upward movement of the ram will cause the lug 43 to engage the angular end 53 of the slide 50, thereby opening the limit switch A and automaticallyv stopping the press.

The armature shaft 42 is preferably provided with a brake 54 normally applied by a spring 55 (Fig. 5) but held released against the tension of'said spring when the motory is running by a solenoid 56 in a shunt circuitV 57 (Fig. 3) between the feed lines'Ll and L2.

Means are preferably provided forindieating the pressure exerted by the press upon the work, said means, as shown in Fig. 1, comprising a dial plate secured by a bracket 121 to the upper end of one of thev posts 18 and having aA suitable graduated scale. Journalled in the dial plate 120 is an arbor 122 carrying at one end a pointer 123` movable over the scale on said dial plate. Secured to the opposite end of the arbor 122 is a pinion 124 wliichjcooperat'es'with a rack bar 125 carried by theframe member 52.` It

- cated' on the dial 120 by the pointer 128 due to the movement of the'bracket 121 relative to the frame member 52.

Iclaim:

31. In a press, the combination with relatively movable press elements, of a resilient element associated with one of said press elements and subjected to the pressure exert'- ed therebetween, means Vfor relatively moving said elements toward one another, comprising a rack carried by one of said press elements, a train of gearing, and an electric motor, means including an electric circuit for controlling said moving means, and means controlled by the yielding movement of said resilient element and consequently by the amount of said pressure for controlling said electric circuit and thereby stopping thel relativefmovement of saidelements when a predetermined pressure has been reached.

. 2. In a press,the combination with relatively movable pressA elements, of an element subjected to the pressure exerted between said press elements and displaceable thereby amounts varying with the amount of said pressure, means Jfor relatively moving said elements toward one another, comprising a rack carried by one ot said press elements, a

`train of gearing, and an electric motor, means including` an electric circuit for controlling said moving means, and means actuated by a predetermined movement of said displaceable element for controlling said electric circuit andithereby stopping the relative movement of said press elements.

3. In a press, in combination, a resiliently supported bed, a ram, means for moving said ram toward and from said bed, comprising a rack carried by saidram,`a train of gearing, and an .electric motor, means including an electric circuit for controlling said moving means, and means operatively connected with both said ram and said `bed for controlling said circuit to stop vthe movement of said ram upon a. predetermined movement of either of said elements. y

4. In apress, in combination, a bed, a resilientsupport for said bed, a ram,'means' for moving said ram towardsaid bed, comprising a rack carried by said ram, a train of gearing, andan electric motor, and means controlled by the pressure exerted between said bed-and ram for controllinglsaid moving means and for stopping the movement ofsaid ram when a Vpredetermined pressure has been reached, said last` named Vmea-ns being also rendered operative to stop said movement upon failureoi said bed to exert its normal reaction to said pressure. f 5. In a press, in combinatiomaa bed, a resilientsupport for said: bed, a ram, means forV the pressure of sai-d ram for controlling said circuit tostop said moving means.

6. In a press, in combination, a bed, a resilient support for saidV bed, a ram, means for moving said ram toward said bed, comprisinga rack carried by said ram, a train of gearing, and an electricmotor, means including an electric circuit for controlling'said.

moving means, and means controlled by the pressure exerted between said'bed and ram for controlling,saidelectric circuit and thereby stopping the movement of said ram when a predetermined pressure has been reached',

said last named means being also rendered operative to stop said movement upon failure' of said bed to exert its normal reaction to said pressure.

7. In a press, in combination, a bed, a resilient support for-said bed, a ram, means including'a rack carried by saidram, a train of gearing-and an electric motor for moving said ram toward said bed, and means Vrendered operative by failure of said bed to exert its normal reaction tov thepressure of 'said ram `i'orbrealiing the circuit to said motor.

8. In a press, in combination, a resiliently su 3 orted bed a ram means for movin@ saidram toward said bed, comprising a rack carried by said ram, a tram of gearing, and an electric motor,`means including an electric circuit forv controlling said moving means, a-

inember movable with said bed, a clamp carried by saidl member, a slide adjustably mounted in said clamp 'and having an'engaging portion, and a member engaged by the engaging portion of said slidewhen said bed yields Jfor controlling the electric circuit and thereby stoppingthe movement of said ram by said moving means.

9.: In a press, in combination, a resiliently supported bed, a ram, means including a rack carried by said ram, a trainl of gearing, and an electric motor for moving said ram toward and fromsaid bed, automatic means loperatively connected with both said ramand said bed for opening the circuit to said motor and stopping the movement of said ram upon a predeterminedl movement ram upon a predetermined movement ot said ram toward and away from said bed, and manually operable means for closing the circuit to said motor and starting the movement of said ram in the opposite direction upon operation' of said automatic means.

l1. ln a press the combination of a bed, a ram, springs for supporting said bed against the pressure of said ram, mechanism for moving said ram toward and away fromv said bed, comprising a rack carried by said ram, a train of gearing, an electric motor, different electrical circuits to said motor for controlling the movement of said ram in either direction, manually operable switches for completing each of said circuits to move said ram in either direction and opening said completed circuit to stop said ram at any position, and means tor automatically opening said completed circuit to stop said ram upon a predetermined movement of said ram in either direction.

12. In a press the combination of a bed7 a. ram, springs for supporting said bed against the pressure lof said ram, mechanism for moving said ram toward and away from said bed, comprising a rack carried by said ram, a train of gearing, an electric motor, different electrical circuits to said motor for controlling the movement of said ram in either direction7 manually operable switches for completing each of said circuits to kmove said ram in either direction and opening said completed circuit to stop said ram at any position, a limit switch in each of said circuits, and a stop device'to control each limit switch Vand automatically open said completed circuit and thereby stop said ram upon a predetermined movement of said ram in either direction.

V13. In a press thel combination of a bed, a ram, springs for supporting said bed against the pressure of said ram, mechanism for moving said ram toward and away from said bed, comprisingV a rack carried by'said ram,a train of gearing, an electric motor, ditlerent electrical circuits to said motor for controlling the movementof said ram in either direction, manually operable switches for completing each of said circuits to move said ram in either direction'and opening said completed circuit to stop said ram at any position, a limit switch in each of said circuits, a stop device to control each limit switch and automatically open said completed circuit and thereby stop said ram upon a predetermined movement of said ram in either direction, and anauXiliary stop device rendered operative'by failure of said bed to exert its normal resistance to the pressure of said ram for controlling its respective limit switch and thereby limit the movement of said ram toward said bed.

ln testimony whereoi1 I aiiiX my signature.

JASPER DERBY.

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