US1283837A

US1283837A - Controlling mechanism for hydraulic presses.

Info

Publication number: US1283837A
Authority: US
Inventors: Eugene L Mcgary
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-05-17
Filing date: 1917-05-17
Publication date: 1918-11-05
Anticipated expiration: 1935-11-05

Description

E. L. IVCGARY.

CONTROLLING MECHANISM FOR HYDRAULIC PRESSES,

APPLICATION FILED MAY 17, 1917,

Patented Nov. 5, 1918.`

2 SHEETS-SHEET I.

E. L. MCGARY.

CONTROLLING MECHANISM FOR HYDHAULlc PRESSES.

APPLICATION FILED MAY I7, 19H- Z SHEETS-SHEET 2.

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GONTROIJLING- MECHANISM FOR HYDRAULIC PRESSES.

Specification of Letters Patent.

Patented Nov. 5, 1918./

Application led May 17, 1917. Serial No. 169,269.

To all 'whom it may concern:

Be it known that I, EUGENE L. MCGARY, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Controllin Mechanism for Hydraulic Presses, of which the following is a full, clear, and exact description.

The invention relates to controlling mechanism for hydraulic presses and similar machines.

In practice, it has been found, particularly Where hydraulic operated machines are` operated under high pressure, as a matter of economy, to employ a fluid under a lower pressure to operate the tool or ram during the idle portions of theA stroke or during those portions of the stroke When the high pressure is not necessary for the Work. In the operation of these machines With fluids of different pressures, When under manual control, extreme care must be taken to prevent the sudden application of high pressure, because of the danger of breaking parts of the machine or the Work and of injury to the machine resulting from sudden application of the high pressure. In many cases, the operators of the machines are paid by piece Work and there is a tendency to prematurely apply the high pressure to save time, and this has been` found to be detrimental to the machine and tools operated thereby.

It has been sought, in practice, to meet these problems by initially choking the high pressure fluid supply, but this has been found to be objectionable because of the loss of time, particularly in certain Work, such as rubber vulcanizing, Where, at times, the full unrestricted flow of high pressure is desired. In other instances, it has been sought to meet these problems in practice by a series of cumulatively opening ports which are successively uncovered as the piston travels its cycle. In these mechanisms, the valves are required to travel `over leather or similar packings which rapidly Wear out and are of doubtful dependency and involve complications which preclude quick repair or adjustment.

A primary object of the present invention is to provide improved controlling means which is automatic in its operation, so that the operator, after starting the machine With lovv pressure, can leave the machine and attend to other Work and in Which the mairimum low pressure first opens a small valve or port to cause the pressure in the machine to be gradually increased until the full dow of high pressure may be safely the machine.

A further object of the invention is to at tain this result by a construction in which there is metal-tometa1 engagement between the valve and its seat so that the high pressure Will not rapidly Wear or cut away the valve or its seat. l

By providing anV improved controlling mechanism in which the operator manually controls the supply of low pressure fluid to the machine, then supplying a choked or restricted ioW of high pressure fluid to the machine When the predetermined maximum of low pressure has been reached and' then causing the increased pressure to lsubseapplied to f I quently, automatically open a valve which permits the full flow of high pressure fluid into the machine, it has been found that danger of breakage or injury to the machine or work is edectively prevented and thev control is automatic so that the operator, after starting the machine, can leave it and attend to other Work.

Another object of the invention is to provide an automatic controlling device of this type which may be readily attached or' ap# plied to machines of usualV construction.

Another object` of the invention is to pro-` vide improved mechanism of this type by which the high and lovv pressures are successively controlled automatically by valves which are constructed for metal-to-metal contact surfaces.

The invention consists in the several novel features hereinafterset forth and more particularly defined by claims at the conclusion hereof.

In the drawings: Figure l is an elevation of a hydraulic press equipped With the .in-

vention. Fig. 2 is a section of one form of controlling mechanism embodying the invention. Fig. 3 is a section of another form of the invention. Eig. 4 is a section of another form of the invention.

The invention is shown as applied to a hydraulic machine comprising a suitable frame 5, a Working cylinder 6 adapted to receive fluid under pressure, a platen 7 adapted to be operated by a piston in the cylinder, and a cooperating stationary member 8 supported by the frame 5, It Will be understood thatJ the invention is adapted to be aplied to any machine adapted 'to be operated y fluid under pressure.

A pipe 9 is connected to deliver fluid under pressure into the cylinder from a casing 10 of a suitable main or manually controlled operating valve 11 which controls the supply of low pressure fluid to the pipe 9.

w pressure fluid is conducted to the casing .10 by a pipe 12 containing-a check valve 14 which prevents the fluid from being forced backw-ardly through the low pressure sup ply. An exhaust pipe l5-is connected to the casing 10' so 'that when the valve 11 is operated to cut off the supply of fluid, the fluid will exhaust from the working cylinder 6 through pipe 9, casing 10 and pipe 15,

The automatic controlling mechanism, as exemplified in Figs. 1 and 4, comprises a casing 17 to which is connected a high pressuresupply pipe 18 and a pipe 19 which is connected to the pipe 9. Pipe 19, in this exemplification of the invention, serves to conduct low pressure fluid from the pipe 9 or the press connection, which is in communication with the working cylinder 6, to the casing I17 'to operate the high-pressure controlling mechanism and also serves to conduct high pressure fluid from the casing 417 to the pipe 9 and the working cylinder at proper times.v A chamber 21 in the casing 17 constantly receives high pressure' fluid from pipe 18 and a chamber 22 is in communication with the chamber 21 by a small poit p 17 and is provided with an is provided atthe upper end of .the -33 to prevent leakage of the fluid. A spring 23, a wear-nozzle 24 `being provided at the point wherev the duct connects with the chamber 21. A valve 20 controls the flow of high' pressure fluid through a duet 25 to pipe 19. This duct is of sufficient size to permit the'maXimum or full flow of high pressure fluid. Valve 20 is normally closed against a metal seat 26 formed in the casing upper stein 27 which is guided in a removable plug 28, a suitable packing 29 being provided below the plug 'to prevent leakage of the fluid. The valve 20 is formed with a shoulder 30 upon which the fluid in the chamber 21 acts to aid lin holding the valve normally closed. The

valve 2O is also provided with a lower stem 31 which extends through and is guided in a removable plug 33. Suitable packing 34 plus lower 35 bears-against the plug 33 and its adjustably end engages a socket 36 which is held on the stem 31 bya nut 37. This construction permits adjustment of the spring 35 to vary the pressure required to open the high pressure valve 20so that the controlling mechanism can be adjusted for different work without dismantling the mechanism. The upper end of stem 27 is accessible so it can be held while nut 37 is beingadjusted.

A small by-pass vport 38 connects cham- -bei 22 and the duct 25 and the upper end of this duct is pro-vided with a valve seat for a gradual flow valve 39 which is normally closed and is guided in a plug 40 which is removably secured to the casing 17. Pachino' 41 is provided at the lower end of plug 40 to prevent the leakage of fluid. A spring 42 is mounted in a socket in the upper portion of plug 40 and is applied rto hold the valve 39 closed. A cap 43 is screwthreaded to the upper end of plug 40. A set screw 44 is adjustably held in said capland serves as an adjustable abutment for the upper end of the spring. A lock nut 45 holds screw 44 in its assigned position. By adjusting screvr 44, the pressure required to overcome spring 42 and open the valve 39 may be varied as desired for different work.

The operation of the construction thus far described will be as follows: When the ram 7 is to be operated, the operator will manipulate the valve 11 which may be of any suitable construction, to cause low pressure fluid to flow from pipe l2 through casing 10 and pipe 9 into the working cylinder 6. Normally, valves 39 and 2() are closed and will remain so until the maximum of the low pressure .fluid has been reached. When that occurs, the pressure of the fluid in duct 38 against the' lower end of valve 39 will be sufficient to open said valve and thereupon a small' volume of high pressure fluid will flow from chamber 21 through nozzle 24 port 23, chamber 22 and port 38 to duct 25 and gradually increase the pressure in the pipe 9 and the workin cylinder. During this operation, the chec -valve 14 will prevent the back-flow of fluid into the low pressure pipe. When the pressure has been gradually increased to a point where substantially the full flow of high pressure fluid may be appliedpwithout danger either to the work or to the machine, the pressure of the fluid `in duct 25 acting against the underside of valve 2O will be sufficient to open said valve against the force of spring 35 and the fluid pressure upon the top of' shoulder 30. Thereupon, the high presure fluid in full volume will continue to flow directly from chamber 21 to duct 25 and through pi e 9 to the working cylinder. As long as tlie valve 11 is allowed to remain open, the full high-pressure will be applied to the ram and work which is a desideratum in some work. The operator, after opening the valve 11, can leave the machine to attend to other work, because the subsequent control is automatic, until the operation has been completed. When it is desired to :release the work, the operator will shift the valve 11 to open the exhaust 15. As soon as there is material drop in pressure in the chamber 25, the valve 39 will be closed by a spring 42 and valve 2O will be closed by spring 35. When the fluid has been exhausted tit ,tion oi the invention in which both the low pressure and the high pressure fluids dow `through the casing oi the controlling-mechanism.- lin this iorm of the invention, the pipe 92L leads from the valvecasingl() and is connected to the casin "179. A pipe 9b connects said casing an the, cylinder 6.

Both oi these pipes communicate with a chamber46 in casing 17a. Low pressure duid will ilownirom pipe 9a through chamber 46 and pipe 9" to the cylinder under control oi the valve l1. A. hollow plug or sleeve 47 oiwear-metal is secured in casing 17 andthe iull Howwalve 30a for the highpressure fluid engages a seat in the upper end of sleeve 47. The stem 30 oi valve 60 is guided in a hollowplug 48 which is se cured vto the casing 17a. `lPackinoI 49 is provided around the lower end of the stem 30 and a spring` 50 engaging theladjustable stop and guide 5l serves to press' valve 30` into its closed position.` A lock nut 52 holds rio l to,

the member 5l against rotation in plug 46. rlhe pressure exerted by this spring may be varied as desired. A ports` is formed vertically through the sleeve 47 anda valve seat 54 is formed at the lower end of said sleeve which is engaged by a gradual dow valve 55 which is normally closed and is adapted to be operated by fluid under pressure in the port 53. rl`he stem of valve 55 is guided in a hollow plug 56 containing a spring 57 for holding the valve normally closed. v'.llhe stem oi valve 55 works through the packing 58. "lhe force oi spring 57 maybe adjusted bya member 59 which is screw-threaded to the lower end of plug 56. .d high pressure supply pipe 60 is connected to casing 178L to deliver duid into a chamber 6l. A small`port`62 in sleeve 47, connects chamber 46 and duct 53 to supply fluid lor openingvalve 55 for gradual delivery of high pressure fluid through port 62 and chamber 46 and pipe 9b to the press. ln this form oi the invention, the valve ll controls the supply oi low pressure duid to the cylinder and chamber 46. When the low pressure duid reaches a predetermined maximum in chamber 46, duct 62 and port 53,' it will act upon the upperend oi valve 55 and forcelit open against the iorce oi spring 57, whereupon the high pressure lluid -from pipe 60 will dowl gradually through the port 62 into the press` connection and cylinder 6.k Alter the pressure has graduallyincreased to the point when it is .t w. that safe to admit lull llow oi high pressure, without dangerto the press or worlr, the pressure oi fluid against the underside oi valveil and against the shoulder 30b on stem 36 will 'be suilcient to open valve 39 against the iorce of spring 50, whereupon the lull ilow oifhgh pressure duidwill pass trom `duct 53 directly into 'chamber 46 andfthence d tothe press c0nnection.` 'lhis iorm ol the invention eremplies one in which Tooth high-pressure and low pressure pipes are connected to the casing oi the controlling mechanism.

lin the i'orm 0i the invention illustrated in liig. 3, the pipe 9 from the press coection pipe 9 (Fig. l) is connected to thecasiri 17 b ofthe automatic controlling mechanis The high pressure pipe 16 is connected to said casin to deliver duid into a chamber 6l. .4 iu l-iow valve 62 o cratesA against a seat 63 and is heldnorma ly closed by a spring 64. rllhe stern 65 ol `valve 62- is provided with a packing 66 held by a iollowe'r 67 and nut 68 `to `prevent leakage ol duid `from the chamber lin which the stemfworlrs. Ain adjust-ing screw 69. serves to vary the pressure' of spring 64 -as desired. This screw is supported in a plate 76 suspended from casing 17? `by rods ll andy nuts` 72.

`The stem of valve"62 entends upwardly trom "the valve and has connected .thereto a sleeve 73 which is slidabl mounted in a guide ring 74 and packing 5. .l gradualdow valve76 for thehigh pressure duid is` mounted to work inthe stem oil thelull dll ldd

when valve`76 isopen. d sprin 76 is ap# plied to hold valve 76 norma ly closed. This spring is mounted in a member 79 secured to the upper end ol sleeve. 75, a

packing 8O being provided to d, prevent lealrage 0i duid around the stemol2 valve76. An adjusting 'screw 6l is provided lor spring 76. Both the adjusting` screws 6l and 69 are accessible trom the outside ol the casing so that thepoints at which the gradual and itull dow valves will be operated may he varied as desired. y

ln the operation et the :torni oi the invention shown in llig. B, pie 9" will ini tially receive low pressure l trom the press connection yunder control oil valve ll (liig. l). en the low pressure duid has reachedthe point when it is salle to gradually admit high pressure fluid, the duid in the press connection, vacting through port 77,' will exert sumcient pressure on the lower end ci `the gradual-ow valve 76 to over-- come the torce el spring76 and open said valve, whereupon high pressure duid trom chamber 6l will Howthrough port 77 and lth gradually increase the ressure in the press. The stem 65 is providbd with a shoulder 65 and the exposed area of said shoulder andthe packing66 is greater than the area of the valve stem and parts moving therethrough which is exposed to counter-pressure' of the fluid in the chamber 61, so that when the ressure in chamber 6l has increased sufhciently to act on said shoulder 10 65 and packing 66 to overcome the force of spring 64, as theresult of the gradual flow of high pressure through port 77, the full-flow valve 62 will be opened and thereafter thelhigh pressure Will flow directly from chamber 6l tothe press. When the fluid is exhausted from the press connection thefspring 64 Will promptly close valve 62 and spring 7 8 will quickly close the low pressure connection. This form of the in- CII v vention exemplifies one in which-the gradual flovv valve is slidably mounted in the stem of the full flow valve.

The invention thus exemplifies an improved automatic .controlling mechanism vfor hydraulic machines or presses in which the' operator manually controls the flow of the low pressure fluid andin which there is a gradual-flow valve for delivering high pressure fluid to the press connection and a full-flow valve controlled bythe fluid under pressure so that the full flow of the high pressure fluid may be maintained as long as desired. AAlso one in which the pressures `at Which the gradual flow and full flow of the high pressure fluid may be quickly varied to adapt the controlling mechanism for different work Without dismantling the controlling mechanism.

f The invention is not to be understood as lo restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus `described Athe invention, what Irclaim as new and desire to secure by Letters Patent, is:

l. In controlling mechanism for fluid pressure operated machines, the combination of a sup-ply for high pressure fluid, a sulpply for low pressure fluid, means for controlling the supply of low 'pressure fluid to the machine and automatic controlling mechanism comprising a gradual flow valve operable by low-pressure fluid, and a separately operating automatic full-flow valve both of said valves being connected to the same high pressure supplyr and to control thev flow of said high pressure fluid from rsaid supply to the machme.

l 2. In controlling mechanism for fluid pressure operated machines, the combination of a supply for high pressure fluid, a supplyfor low pressure fluid, means for controlling the supply of low pressure fluid to the machine and automatic controlling mechanism comprising a gradual flow valve operable by low pressure fluid and a separately operatin full flow valve operable only by fluid of greater pressure than the low-pressure fluid, both of said valves beylng connected to the same high pressure supply and to control the flow of said high pressure fluid from said supply to the machine.

3. In controlling mechanism for fluid pressure operated machines, the combination with a hydraulic press, of a supply for high pressure fluid, a supply for low pressure fluid, a check-valve in the loW- ressure supply, means for manually contro ing thc supply of low pressure fluid to the machine and automatic controllin mechanism comprising a gradual flow va ve operable by low pressure fluid and an automatic Vseparately operating full flow valve, both of said valves being connected to the same high pressure supply and to control the flow of said high pressure fluid from said supply to the machine. y

4. `In controlling mechanism for fluid pressure operated machines, the combination of a supply for high pressure fluid, a supply for lo-W pressure fluid to the machine, automatic controlling mechanism comprising a gradual-flow valve operable by low pressure fluid and an automatic separately operatingfull-flow valve, both of said valves being connectedto the same high pressure supply and t0 control the flow of said highpressure fluid from said supply to the machine, and means for varying the operation of said valves so they wlll be opened at different pressures.

5.. In controlling mechanism for fluid pressure operated lmachines, the combination of a supply for high pressure fluid, a supply for low pressure fluid, means for controlling the supply of 10W pressure fluid to the machine, automatic controlling mechanism comprising a gradual flow valve operable by low pressure fluid and a separately operating full flow valve operableby fluid pressure, both of said valves being connected to the same high pressure supply and to control the floW of said high pressure 115 fluid from said supply to the machine, and means accessible from the outside of said mechanism, for varying the operation of said valves so they will be opened at different pressures.

6. In controlling mechanism for fluid pressure operated machines, the combination of a supply for fluid under low pressure, a supply for fluid under high pressure, a manually operable valve for controlling 125 the flow of lovv pressure' to the press, a fullflovv valve for the supply of high pressure to the machine, and means in virtue of Which said full-flow valve is operable only by a predetermined pressure of fluid in ex- 130 masser cess of the maximum Working force of the louT pressure Huid shpplied to the machine, and when the working force of the low pres sure fluid has been, supplemented by fluid from the supply offhigh pressure controlled by the full flow Valve.

7. ln controlling mechanism for Huid pressure operated machines, the combina- .tion of a supply for duid under low pres- -sur/e, a sup-ply for Huid under high pressure,

a manually operable valve for controlling the flow of low wessure to the machine,l an automatic gradual flow valve operable `by low-pressure fluid, for controlling the sup'- ply of high pressure to the machine a fulliow valve, and means in virtue ci which said ulliiow valve is operable only by a predetermined pressure of Huid in excess of the maximum Working force of the low pressure Huidsupplied to lthe machine, and when the Working force of the low ressure fluid has been sup lemented by Huid from the supply of hi'g pressure controlled by thefull liow valve.

8. ln controlling mechanism for Huid pressure operated machines, the combination of a supply for fluid under 10W pressure, a supply for fluid under high pressure, a manually operable Valve for controlling the flow VVont loW pressure to the machine, an automatic gradual-How' Valve operable by low pressure fluid for the supply'of high which the gradual and full-How valve will open may be varied from the outside.

9. ln controlling mechanism for Huid pressure operated machines, the combinal tion of a supply for high pressure fluid, a supply for low ressure Huid, means for manually controlhng the supply of low ressure Huid to the machine and contro ing mechanism comprising a casing, a connection for delivering lowy pressure Huid to the casing, said high pressure supply being. connected to deliver fluid to said casing, a gradual-flow valve operating in the 4casin and operable by low pressure duid to contro the. gradual flow of high pressure Huid to the press connection, a full How valve Jfor the high pressure fluid in the casin and means in virtue of which said ful A--lioW Valve is operable b Huid in the press connection after the duid has been delivered thereto through the increase .of pressure from the gradual flow of high pressure Huid,

EUGENE L. MCGARY.