US556196A - mqlas - Google Patents

Description

(No Model.) 2 sheets-sheet 1 J. MOL-AS.

, HYDRAULIC PRBSSURB'MACHINE. No. 556,196 Patented Mar. 10, 1896 LNDREW B GRAHAM PHDTD'LITHO WASHINGTON DC 2 Sheets-Sheet 2? (No Model.)

J.MOLAS. HYDRAULIC PRESSURE MACHINE.

Patented Mar. 10,1896.

M I .J. r WMW I rm, m

ANDREW a sRAuAM Pnmomnu wAsmNmiLh'e UNITED STATES PATENT OFFICE.

JEAN MOLAS, or LONDON, ENGLAND.

HYDRAULIC-PRESSURE MACHINE.

SPECIFICATION forming part of Letters Patent No. 556,196, dated March 10, 1896.

Application filed October 21, 1895. Serial No. 566,411. (No model.) Patented in England January 3, 1895, No. 224; in Belgium (Jctober 28, 1895, No. 118,081, and in Italy December 2, 1395, LXXVIII, 371.

To all whom, it may concern.-

Be it known that I, JEAN MOLAs, a citizen of England, residing at 2 17 High Road, Queen Annes Avenue, South Tottenham, London, in the county of Middlesex, England, have invented certain new and useful Improvements in Hydraulic-Pressure Machines, (for which I have obtained Letters Patent in Great Britain dated January 3, 1895, No. 224:; in Belgium, dated October 28, 1895, No. 118,081, and in Italy, dated December 2, 1895, LXXVIII, 371,) of which the following is a specification.

My invention relates to the construction of hydraulic-pr'essure machines, such as hydraulic presses, lifts, cranes, or engines, in such a manner that the expenditure of the motive fluid, such as water at high pressure, is approximately proportioned to the work that has to be performed. I efiect this by arranging in a hydraulic cylinder a number of concentric annular pistons, in combination with a tubular supply-valve differentially loadedin such a manner that according as less or greater working pressure is required the valve is automatically made to take such a position that the motive fluid is brought to act on a piston-surface of less or greater area, a less or greater fraction of the total capacity of the cylinder being thus charged with m0- tive fluid, so that the expenditure of fluid is made to correspond approximately with the work done by it.

My invention may be applied in a regulating-cylinder from which fluid under pressure is sent to the working cylinder of ahydraulic lift, press, crane,-or the like, the same fluid returning to the regulating cylinder after performing work, or it may be applied in a direct-acting cylinder in which the motive fluid acts directly on the ram or plunger of the lift, press, or crane, as Ishall describe, referring to the accompanying drawings.

Figure 1 is a vertical section of a regulatingcylinder for transmitting pressure to a Working cylinder, with means according to my invention for automatically suiting the pressure and expenditure of motive fluid to the load on the piston or plunger of the working cylinder. Fig. 2 is a vertical section of a directacting press or lift cylinder also arranged according to my invention. Fig. 3 is a part section of the apparatus shown in Fig. 1, show ing a modification.

Referring first to Fig. 1, the regulating-cylinder A, which communicates by a pipe or conduit B with the working cylinder of a hydraulic lift, press, crane, or the like, and which has the same capacity as that working cylinder, is fitted with a piston 0 having a central boss D and several concentric annular plungers, the upper ends of which are formed as pistons E, F and G, each provided with suitable external and internal packings.

K is a central supply-valve in the form of a tube, which is fitted to slide vertically and extends up through cavities formed in the head of the cylinder. It terminates in a rod k of smaller diameter, which passes out through packing and has a cross-head and side rods to carry weights L in the form of segments resting on shoulders of guides so arranged that as the rod it rises one after another of the weights is lifted, the load on it being thus increased step by step as it ascends.

In the upper part of the tube K there is a lateral orifice M, which is always open to a cavity in the cylinder-head, this cavity communicating by a pipe or conduit N with the operating valve or valves for supplying highpressure water and discharging the water when the work is done. The conduit N has two branches at leading to a discharge-valve, and at leading to a supply-valve, both of these valves being of any known kind arranged to be worked separately. In the branch n there is a valve S, the stem of which passes through packing and is externally connected to a tube 8 having within it free to slide a rod T, which is attached to the piston O and has a head't, the length of the tube .9 being such that when the piston O approaches the lower extreme of its stroke the head i, acting on the lower end of the tube 8, draws it down and closes the valve S.

The apparatus operates as follows: Assuming that a light load has to be raised by the piston or plunger of the working cylinder, the high-pressure Water raising thevalve S is supplied at N and enters the tube K by the orifice M and acts on the area of the boss D, causing the piston O to descend and to force fluid by the conduit 13 into the working cylinder.

Should the pressure thus transmitted to the working cylinder be insufficient to overcome the load, then as the piston C and its boss D cannot descend the pressure in and under the tube K increases, and the tube is forced upward in opposition to the weight L until the lower mouth of K is in such a position that the service-pressure acts 011 the larger area of E, as well as on D. If this pressure on the larger area be still insufficient to force down the piston (J, the tube K is still farther raised, lifting an added weight and allowing the pressure to act also on 1*, and it may be then on G until the total area on which the press ure of the water acts is such that the piston O is forced down, transmitting to the working cylinder pressure su'llicient to overcome the load therein.

The movement of the lift or other machine worked by the pressure transmitted from the regulating-cylinder may be arrested at any part of the stroke by closing the supply-valve in the branch at, and when the stroke is completed the valve S is automatically closed. 011 opening the discharge-Valve in the branch '12, allowing the water to escape at N, the fluid returning by 13 from the working cylinder raises the piston C, and the pressure acting on the rod being relieved the tube K is pushed down by the weight L. I prefer to form a lateral slit 7; extending some distance down the tube K, so as to give a larger area of passage for water as the tube rises and has to supply water to a larger space. \Vhen the fluid under the piston G is water, or the same as the service iiuid which acts above the piston, I provide, as shown in Fig. 3, a passage Q with a check-valve V, and 011 the bottom of the cylinder A a projection a.

\Vhen the piston 0 reaches the bottom of the cylinder A the valve V is slightly lifted by a, allowing Iluid to flow by the passage Q from above the piston into the space below it, so as to make up for any loss by leakage from the working cylinder or its connections. The

concentric annular pistons, as well as the main piston, are lubricated by oil supplied to cavities O, and the annular pistons are grooved for passage of oil except near their packings.

Referring now to Fig. 2, in which the same reference-letters are employed to denote parts corresponding to those in Fig. 1, instead of the service-water being applied to push down a piston C, it is applied to push up the table WV of a press or lift, acting, as described with reference to Fig. 1, on a larger or smaller one of the piston areas D, E or 1 according as the load on Wis greater or less, this being determined by the position of the sliding tube K. Instead of employing weights successively lifted to resist the outward pressure actil'lg on this tube, a single weight L may be attached to a lever-armraised to successive positions by a rack on the rod 7t acting on a toothed segment. w is a screw-plug which can be loosened to allow escape of air.

Instead of the number of concentric pistons shown in the drawings, a greater or less 11 umber may obviously be employed, according as it may be desired to have smaller or greater gradations in the variations of the uressure and of the expenditure of motive fluid.

Having thus described the nature of my invention and the best means I know for carrying the same into practical effect, I claim In a hydraulic cylinder, a number of concentric annular pistons presenting successively-increasing areas, in combination with a central supply-tube automatically moved by pressure of the motive fluid to such a position as to bring the fluid to act on a greater or less one of the piston areas, according as the main piston or plunger of the cylinder is subject to a greater or less load, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 41th day of October, A. D. 1895.

J. MOLAS.

\Vitnesses HAROLD IMRAY, JNo. 1. M. MiLLAnn.

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