US2381125A - Apparatus for bumping platen presses - Google Patents

Description

Aug. 7, 1945. A. HERMANN 2,381,125

APPARATUS FOR BUMPING PLATEN PRESSES Filed Oct. 28, 1942 INVENTOR BY A.b22zmzusr ATrOR EY 'lically from its full line position Patented Aug. 7, 1945 srrm'rus run some mm W messes Arthur Hermann, Roch Taylor InstrumentCom ester. N. Y., uslgnor to ponies,

a corporation or New York Rochester, N. Y.,

Applicatiorrootober as, 1942, sci-u No. lea-11s cycle of operations controlled by the motor. The

'zclaims.

This invention relates to an arrangement for controlling the operation 01 a press utilized in molding or treating rubber or other plastic ma terials.

In the operation of suoh'a press, it has been found desirable after initially closing the mold sections thereof to "bump" the press, that is, to open these sections oi' the stock in the mold, as generally disclosed in the patent to Winegar 2,222,732, patented November 26 1940.

The present invention has for its purpose an improvement in the arrangement disclosed in that patent whereby the bumping operation will be even under extremely adverse conditions.-

In the drawing, there is illustrated a conventional form of hydraulic press comprising a base 5 having a deck I and a top plate It held'in rigid spaced relation by means of pillars 1. Within the base there is mounted the plunger 0 draulic ram provided with a suitable head 8, the plungerwith its head being movable hydrauto its dotted line position. As herein illustrated, the plunger is elevsted first by a low pressure liquid or the order of 80 to 150 lbs. sq. in. pressure to substantially its final position wherein high pressure liquid of the order of applied to the plunger 6 to insure closure of the molds. The application of this low pressure liquid followed by the application of the high pressure liquid is controlled by a pneumatically operated valve, the construction of which will best description of the operabe understood i'rom the tion oi the system.

In the operation of such a press, to employ a time cycle device '1' it is. customary which automaticaliy controls the sequence aswell as the duration of the several operations of the press, namely, the closure of the press. the duration of the bumping-cycle, the duration or the closure of the press.

With this brief description or the apparatus, the present invention will best be understood by describing a portion or the operation oi the systent. The operator depresses a pushbutton B provided on the timer T to initiate the operation or the timer including the opening or the air rellay valve II, which extends the air supply in the pipe I! to the pipe l 'Ihedepression ot-the push button B also completes a circuit (not shown) for the timing motor (not disclosed) which measures the various time periods in the m 20 into the ram. This M 1122 to the 1000 to 2000 lbs. sq. in. pressure is 39 timer during its "bumping" period opens the valve I! to extend the 11 supply However, at the conclusion of this "bumping? period, the timer will close the valve H to cut 01! the air supply from the pipe it. As soon as the air supply is opened into the pipe I, this air pressure is extended through the relay valve i'l since its plunger II is normally in a position to permit the compressed air to pass to the pipe i8 and thence to the diaphragm motor top 20 or the v The application 01' this compressed air to the diaphragm motor 20 moves the valve discs 22 and 23 to their alternate position from that shown. to prevent the iluid within the ram from draining away through the pipe 24 while valve disc 23 is unseated so that the low p source of liquid 28 flows from pipe 25 through the pipe elevates the plunger 3 and its head 5 until the head closes mold sections Mi, M2. The pressure then builds up in the pipe 20 until the valve 27 is opened to connect high pressure liquid in the ram. The application of this high pressure causes the ram head to apply high pressure to the mold sections. It will be noted thst the check valve to in the main valve ll prevents high pressure fluid from flowing cock into the low pressure pipe it. When the high pressure fluid is applied to the ram. as just described, this pressure is communicated throush the conduit II to the C spring 32. spring tends to unwind and by so doing oi the switch ill. he soon as this switch is closed, the solenoid m is operated in a circuiteg from the power lead It, winding of the solenoid iii, contacts of the'switch M, now the other conductor II of the power The solenoid II when thus operated closes n locking circuit for itself traceable from the a. lead conductor 84, winding of the solenoid it. the armature 8B and front contacts of solenoid,

conductor tT-throush the contacts oi s limit switch It, now closed, to the power. conductor it.

It should be mentioned that the switch It is nor= positions so that the amount or opening of the press during the bumping cycle can be adjusted at will. Also when the relay II is operated, it closes a circuit for operating the solenoid it or the solehold-actuated valve,.which circuitextends irom pipe to the pipe l5.

The valve disc 22 thus engages its seat pipe 28 to the pipe ltleadclosed by the C spring $2, to

is diustable to various vertical 'plunger upward .itsvalvedimsfland lead ll. winding the solenoid a.

the power l0, armature ll, and front contacts of conductor the solenoid I3, conductors l2 and 43, front con- 'ward. Thisswingsthe lever ll about its pivot ll. Asa result'oi this movement, the plunger l1 .0! the valve is moved to the position wherein itcloseatheopeningtothedrsinpipelland extendsthepipe ill tothepipellleadingtothe capsular chamber I! o! a pilot valve. quently, when the timer opens valve the "bumping" period, compressed pliedto chamber ll.. Assresultoi tion of compressed air. the c and elevates the valve disc Uiagainst its Compressed air iron! pipe ll leaks er II at 1: into space II where it forces into a position wherein it cl theopeningiromthepipe ll cuttinsoi! supply to main valve 21 and connects the to the vent i2. Compressed air isthus drained motor II of the main trsted. The hydraulic liquid thereupo to flow away from them so that the ram headstartstodescendi'rom its dottedline position. This head as it moves its in: II to open the switch 80. The opening oithis switch interrupts the locking circuit of the solenoid st so that it deenergim. On the deenergisation of the solenoid 88, solenoid ll has its 0 circuit interrupted so that its come It and the lever GI descend moving the valve plug 41 to the position shown. The compressed air which previously had been applied through pipes Hand 4! to the capsular chamber ll leaks away 40 said puts and mm through the vent I. The chamber 80 contacts to withdraw the valve disc Bl away from its seat. Thiscauses the valve plug it to move to its position wherein compressed air is again applied through the pipes It and is to the motor dia-.- phragm II of the valve !I.. This valve will move -28 to their alternate positions from that shown, all as previously described. Low pressure hydraulic fluid through the pipe II wlllbe applledto the ram to elevate the ram. head as before. Then when the ram head is in engagement with the mold sections hil W hydraulic fluid in the pipe 2. will be pplied to theram. Assoonasthishishpressurehydraulic fluid is applied to the ram. this high pressure will be communicated through the conduit" to the C spring 82; Spring it closes the switch causes the operating meehanislnto repeat the humping operation. all as previously 7 Then beroitimesthatthepressisclosedand then to constitute each bumping operation can 'be determined -at will-by the operation of the timer. The duration of this bmnpins period, as previousix mentioned, is governed by the length'ot-the interval which the timer maintainstherelayvalve l2 o'pe'ntoeonnect a; from the suppiy'pipe lrto the pipe I. v clusion oi. the bumping close to shut oi! the means including a main valve operable to alternate positions for 199M118 to and !or exhausting pressure fluid from said motor, a limit switch operated by the opening of said press parts to a predetermined position, a fluid ressure operated switchclosedinresponsetoapredetermined value oi the pressure fluid in said'motor and opened in response we lower pressured the .fluid in said motor, mechanism including a solenoid valve for moving said flrst valve to its sshaust position. an operatins circuit for solesurooperated switch noid c! said valve completed in response to the closure or both otsaid switches. said limit switch on serving to interrupt saidcircuit wherehysaid solenoidvalveandthemechanism otwhichitisaparitoperatethemainvalveto the position in which it rsapplies pressurefluid tosaidmotor,andmeansiorrenderinsssid mechanism inoperative and thus maintain the pressclosed. p

zlnapresathecomblnationorapsiroi' opposed ptesspartsrelatively movable towardand awayiromeachothena-motoroneratedhytbe a plication or pressure fluid thereto-tor closing by the exhausting or pressure fluid theretromdor opening saidparts. means including a main valve operable to alternate positions for applyins to and for exhausting pressure fluid from said motor, a normally closed limit switch opened by the opening oi said press parts to a position, a fluid presdeterminedpremureoi'thepressurefluidinlaid motorandopenedinresponsetoaprenureoi the fluid in said motor below said predetermined including a solenoid valve Pressure. echanism for moving said that valve to its exhaust polltion, an actuating circuit tor the solenoid of said n which described. 5

valve, a relay operatins tooomplete said 'actu-' sting circuit, a' primary-circuit tor said relay completed'hy the closure of said pressure fluid operated switch and said relay completed at said limit switch. said limit switch on op ration serving to interrupt said maintaining circuit whereby said solenoid valveandthemechanismotwhichitisapart. operatsathe main valve to the position in which it reapplies pressure fluid to said motor, and means for said inoperative and thusmaintain the press closed.

ans-nun a maintaining circuit for

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