US1888990A - Automatically controlled hydraulic press intensifier - Google Patents

Description

Nov.

29y 1932. F. KURATH AUTOMATICALLY coNTRoLLED HYDRAULIC PRESS INTENSIFIER Filed Aug. 16,` 1929 Patented Nov.a 29g 1932 STATES PATENT QFFICE FRANZ KURTE, @F CHICAGO, ILLINOIS, ASSIGNOR T0 ECONOMY FUSE AND MFG. C0,

GF CHICAG, ILLINOIS, A; COREORATION OF NEW YORK ATMATICALLY CONTROLLED HYDRAULIC PRES-S INTENSEBIER Application led August 16, 1929, Serial No. 386,252.

This invention relates to improvements in automatically controlled hydraulic press intensiliers, and more particularly to improvements in hydraulic presses whereby an automatic control is provided to initially aotuate the press at a low pressure and finally increase the pressure suciently high to perform the desired. pressing operation.

Hydraulic presses such as used in moldingfoperations are commonly operated by being connected to a low pressure fluid supply line. 1t is therefore necessary to use some arrangement of pressure intensier which may comprise a slidable piston, the

'ends of which are ofdiderential diameters whereby .the low pressure acting upon the larger end will transmit a greatly increased pressure to iiuid acting upon the ram of the press. llt is not desirable immediately to apply the high pressure upon actuating the press, and therefore manually controlled valves have heen'provided so that the low pressure initially moves the press platen into engagement with the work, whereupon by a manual control the low pressure is admitted to the pressure intensifier, thus developinfr the high pressure on the ram. s

statedu former constructions required two manual operations..

Sii)

llt is the purpose of this invention to improve upon the eiciency of apparatus of the type described, whereby the operator only needs to act-nate one main valve. whereupon by automatic operation the ram will be moved into engagement with the work at amount; of high pressure piping` resulting in a more compact apparatus with less liability of leakage or damage by bursting of the pipes.

Further and additional objects and advantages of my improvements will be more readily apparent from the .following (le-- scr1pt1on taken in' connection with the` attached drawing, in which a preferred embodiment is specifically shown..

In the drawing,

Figure 1 is a fragmentary sectional elevation through a portion of ahydraulie press illustrating the improved intensifier and they automatic control therefor the parts being shown in high pressure position with the press platen 1n engagement with the work.

Figure 2 is a fragmentary sectional elevation similar to Figure 1, but illustrating the parts in low pressure position.

In describing my invention, it will be understood that the apparatus is adaptable to many forms and arrangements of presses, and the pipingl connections may `be considerably modified without departing from the spirit of my invention. Since the press may be loit any conventional type, only a fragmentary showing' has been made. Thus/in the drawing, 10 is a fixed lower press platen, while 11 is an upper vertically movable press platen. 1t will be understood that the upper press platen is guided in any desired manner. and is preferably normally held by springs or other means in raised position. The piece of work shown in dotted lines is designated 12. AFigure 2 shows the upper platen 11 in raised position, while Figure 1 shows the platen in engagement with the work 12.

A vertically slidable piston ram 13 is ram 13 and prevents leakage of the high fluid pressure. the packing being retained by the flanged ring 16 .which is bolted into the lower end of the cylinder 14. The cylinder 14 is closed at its upper end by a head 17, having an opening 18 extending therethrough. The f upper portion of the opening is enlarged and screwthreaded as at 19 to provide a seat and means for attaching a housing forming a. pressure intensifier 20. The intensifier 20 includes a cylinder 21 closed at the upper end -bv a head 22 vand at its lower end by a cylindrical block 23. 'lfhecylindrical block 23 into the opening 18 and thus into the chamber i 28 above the ram 13. The block 23 is formed with a tubular recess 29 which is oit a substantially smaller diameter than the main part ot the chamber 30 within the cylinder 21. The two chambers ot diderent diameters 29 and 30 arey in communication and i serve to .guide a slidable piston 31. @ne end of the piston 31 extends to a head 32 and is et small diameter to be received in the chamber 29. 'lhe other end ot the piston designated 33 is of lar er diameter and slides in the chamber 30. up-shaped leather packing 3d is attached to the lower face o the head 32 and similar cup-sha ed packing 35 is attached to the u per ace ci the head 33.

A lluid supp y line Ll() extends from some suitable source ont low pressure duid which may be preferably oil. Supply line Li0 has connecte therein, a T-connection d1 to which is attached the pipe 412. Adjacent the ln-connection 'l1 is a checlr valve d3 which acts to allow the huid to dow from the right to the left as shown in the drawing, but will prevent any backward how of the duid. To the lett ot the check valve d3 is a three-way valve tl operated by the handle t5. 'llo one side ot the three-way valve is attached a return pipe 416 and upwardly extending from the valve it is a pipe connection d?. A. short connecting pipe i8 threaded into a wall ci the cylinder M communicates with an o ening t9 which leads into the chamber 28 above the ram 13. Another connecting pipe upon operation of the apparatus, constitutes an extension of the ipe l2 and is threaded into the head 22 ot t e intensifier cylinder 20, a suitable opening 51 being formed in the head 22. A return line 52 is connected to the opening 53 at the lower end ot the chamber 36 and beneath the enlarged piston head 33 ot the pressure intensifier. The return line 52 connects to the main return line t6 at the 1F-coupling 5t. lin line 52 is provided a iT-coin piling 55 to which is attached a pipe connection -56 which is in communication with the pipe 50 when the apparatus is not in use.

lit will be understood that admission ot low pressurethrough the pipe t8 will cause the ram 13 to torce the platen 11 into engagement with the work and at the same time will impart an u ward thrust to the piston 31. Admission o low 'pressure to the pipe 50 due to the diderence in areas of the heads of the piston 31 will result in a greatly increased pressure being transmitted to the chamber 28 and thus cause the ram 13 to impart the To the right ofthe head 6e neaaeeo desired pressure to the work. lt is desirable Athat the apparatus be automatic in its operation, whereby the operator will need onl to move a main control valve. Thus, accor ing to my invention, the operator places the work in position and then moves the main valve tt, whereupon the platen 11 will be moved into engagement with thework at a low pressure and by automatic operation the pressure will be brought up to a high working pressure. Upon completion ot the pressing operation., the operator only needs to move the val-ve 111, whereupon the parts return to their initial position.

The automatic control comprises a iioating piston generally designated 60 which is enclosed in a suitable casing 61. rl`he casing 61 includes a chamber 62 of large diameter and a chamber 63 of small diameter. rl`he piston 60 is formed with a left hand head 61 which tightly tits the large diameter chamber 62. is a cylindrical portion 65 which closely lits the smaller chamber 63. rlhe right hand head 66 of the piston 60 is of the same diameter as the cylindrical portion 65 and closely tits the chamber 63. Between the cylindrical portions 65 and 66 is a reduced neck 67. rl`he left hand end only of the piston 60 requires to be sealed, and it is provided with a cupshaped leather packing 68. The connection pipe 47 is threaded into the wall of the casing 61 and communicates with the duct 69 which leads into the chamber 62 to the left et the head 6d. A similar duct 70 entends trom the chamber 62`to communicate with the pipe 48 which is also attached to the casing` 61. 'lhe pipe connection 4t2 is threaded into the right hand end of the casing 61 and communicates with a duct 71 extending to the extreme right hand end of the chamber 61 and a duct Z2 which extends to an intermediate portion of the chamber 63. rl.`he ipe connection 50 is attached to the upper side ot casing 61 at an intermediate point and communicates with the duct 73 which extends into the chamber 62 at a oint between the duct 7 2 and the left brandend of the chamber 62. The return connection 56 is also attached to the casing 61 and communicatesl with the duct 74 at the point between the chambers 62 and 63. Cylindrical recesses '(5 are provided in the interior et the casing 61 and connect with the litt" ice ducts in order to permit tree dow. A control valve 7 6 may be provided in the pipe line t2 and is actuated by the handle 77. rlhis valve 'i' 6 may or may not be necessary or desirable. The o eration oi the apparatus will now be descri ed.

The parts are shown in idle position in Figure 2, with the platen 11 in raised position. 'lhe valve handle 45 has been moved to an operative position, and will permit the oil pressure duid supply to dow from pipe line t0 through the check valve 43 through tra ' act through the pipes the valve 44, through the-piple connection 47,

through the duct 69 to yt e chamber 62 through the duct into the pipe 48' and from the pipe 48 directly into the chamber 28 behind the iston13. The low pressure will serve to orce the ram 13 downward against the resistance of the springs or other means which hold the platen 11 in raised position, and will force the platen into engagement with the work. At the same time,

the low pressure will act upward against the lower head 32 of the intensifier piston 31 and will force the iston 31 from its lowered position shown in igure 2 to the raised position shown in Figure 1. During this movement oi the pistou 31 the pipe line 52 is open to return while the pipe line 5@ on the upper end oi the intensifier chamber 3G is also open to return by communication through the duct 7 3 to the reduced neck portion 67 of the automatic piston 60. rlihe reduced neck portion 67 is also in communication with the duct 74 and thus through the pipe 56 to the return pipe line 52. Theretore, there is no resistance to upward movement of the piston 31. At the same time the pipe line 42 will transmit low pressure. to the right hand end of the chamber 63 which will be initially closed by the head 6.6 of the iston 60 which is in a position moved to the et hand end. As soon as the platen 11 is in engagement with the work, the low pressure will build up in the chamber 62 to the let oi the head 64 and will finally be sumcientl to move the piston 6() to the right, since the head 64 is oi larger area than the head 66. The movement of the piston 64 may be manually controlled by the operation of the valve 76. Thus ii the valve 7 6 is in closed position the piston 60 will not be moved. When the pistou 60 is moved to the right, the parts will be in the position shown in Figure 1. The low pressure duid supply will then How through the pipe 42 through the duct 72 along the reduced neck portion 67 on the piston 60 through the duct 73 and through the pipe line 50 into the upper end ot the intensifier chamber 30 and therefore lact upon the large diameter-head 33. A greatly increased pressure will therefore be developed by the small diameter head 32 and be transmitted to the chamber 28 and tend to force the piston 13 downward. The line 52 will still be open'tov return, but the pipe connection 56 will be vclosed by the movement of the cylindrical portion 65 of the piston 60 into the chamber 63. The high pressure will also 48 and 47 but will be stopped by the check valve 43 from flowing backward through the low pressure line.

It will therefore be apparent that the high pressure is `confined to the ram chamber 28,

the lower portlon ofthe chamber 29 of the intensifier, the left hand end of the chamber 62 of the automatic valve and the pipe connections 47 and 48. The packings 34 and 68 must therefore be suiliciently tight to prevent leakage. The high pressure will act and .cause the pressing operation to be carried out. Upon completion, the operator moves the valve 45 in order to open pipe line 47 to returnl through the pipe 46. The pressure will therefore be relieved from above the ram 13 and the ram will be returned to its upward position by any means such as springs. The release of the pressure at the left hand of the piston 60 will allow the piston 60 to be forced to the position shown in Figure 2, and the piston 31 will then be open to return on each side and will therefore drop to the position shown in Figure 2. The parts will then be in position for another operation.

Various modifications and changes may be resorted to in adapting my invention to conditions oi use, without departing from the spirit and scope of my invention as expressed in the appended claims.

I claim:

1.. Apparatus for carryingout pressing operations comprising a presscylinder, a low pressure iiuid supply, a fluid supply line leading from said low pressure supply to said c linder, means in said vline controlling the ow of fluid therethrough, a pressure intensifier associated with said press cylinder and transmit high pressure to said the admission of low pressure to said intensifier, a luid supply line leading from said low pressure supply to said intensiier, means for controlling the flow of iiuid through said last' mentioned line, said last named means being associated with the fluid supply line to said cylinder to be automatically operated upon the admission of low pressure to said cylinder and additional manually adjustable means in the supply line to said intensifier to control the rate of actuation of said intensifier.

arranged to cylinder upon 2. Apparatus for carrying out pressing op-A erations, comprising a press cylinder, a low pressure 'luid supply, a. iiuid supply line leading from said low pressure line to said p ress cylinder, a manually operated valve in said supply line, a pressureintensiier associated with said press cylinder and including a differential piston arranged to receive low pressure at one end and to transmit high pressure from the other end to said press cylinder, a fluid supply line leading from said lowy pressure supply to said intensifier, an automatically shiftable plunger associated with both of said supply lines and arranged to control the admission of low pressure toA said intensifier, said plunger being operated upon the admission of low pressure to said press cylinder and a manually operated valve in the supply line between said shitable plunger and the low pressure supply arranged to control the speed of movement ofI l said shiftable plunger.

3. ln a hydraulic press, a main pressure cylinder, a ram movable therein, a low pressure fluid supply line leading to said main cylinder, a check valve in said fluid supply line preventing back flow at any time, an auxiliary cylinder, a dill'erential piston slidable therein having a large head at one end and a small head at the other end, a fluid passage leading I reaches a predetermined amountand addiLL tional means for controlling the rate ot automatic operation of said valve whereby the movement of the di'erential piston produces a pressure in said main cylinder and upon said ram greater than the pressure of the low-- pressure fluid supply.

ll. ln a hydraulic press, a main pressure cylinder, a ram in said cylinder, a pressure intensilier having its high pressure side in communication With said main cylinder, a low pressure iiuid supply line leading to said main cylinder, a branch duid conduit leading from said supply line to the low pressure side of said intensifier, a check valve in said supply line between the said branch conduit and said main cylinder preventing back dow of the `fluid at'any time, a differential piston valve normally held in position by the duid pressure in said branch conduit acting on the small end of said piston valve,`said piston valve in normal position closin said branch conduit to prevent actuation ot said intensi lier and being exposed at its large end to the pressure developed in said :main cylinder whereby the development of a predetermined pressure in said main cylinder causes automatic shifting of said piston valve to permit actuation of said intensifier and a manually adustable valve in said branch conduit between said supply line and said piston valve tor controlling the rate of shitting movement of said valve.,

5. ln a hydraulic press, a main pressure cylinder, a ram in said cylinder, a pressure intensifier having its high pressure side in communication with said main cylinder, a low pressurel lluid supply line leading to said main cylinder, a branch fluid conduit leading from said supply line to the low pressure side of said intensifier, a checlr valve in said sup ply line between the said branch conduit and said main cylinder preventing back tlow of the fluid at any time, a manually-operable two-way valve between said check valve and said main cylinder, a drain leading from said two-way valve, a did'erential area piston valve exposed at its small end to the presassenso sure in said branch conduit and ex osed at its large end to the pressure in the uid supply conduit between said two-way valve and said main cylinder, said piston valve being normally urged into position to close said branch conduit to prevent actuation ot said intensifier and adapted to be automatically shifted to open said branch conduit upon the development of a predetermined pressure in said main cylinder, the shifting movement of said piston valve causing a back flow of uid in said branch. conduit towards said fluid supply line and a manually operable valve for controlling the basl; How ot' duid in said branch conduit to control the rate of shitting movement oit said piston valvea l Signed at Chicago, illinois, this 'lth day ot August, i929.

v FRANZ KURATH.

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