US1921955A

US1921955A - Hydraulic mechanism

Info

Publication number: US1921955A
Application number: US369454A
Authority: US
Inventors: Harry F Vickers
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-06-08
Filing date: 1929-06-08
Publication date: 1933-08-08
Anticipated expiration: 1950-08-08

Description

Aug.. 8, 1933- H. F. vxcKERs HYDRAULIC MECHANISM Filed June 8, 1929 2 Sheets-Sheet l g @y i933 H. F. vncKERs 11,9%,955

HYDRAULIC MECHANI SM Filed June'8, 1929 2 Sheets-Sheet 2 ffy. 4

Patented` Aug. 8,1933 i d l UNITED. STATES PATENT ori-lcs HYDRAULIC MECHANISM Harry F. Yickers, Los Angeles, Calif. i Application Juney 8, 1929. Serial No. 369,454

, 6 Claims. (Cl. (io-52) f This invention has to do with a hydraulic a hydraulic mechanism such as a press or ram mechanism and relates more particularly to a operated by a constant fluid supply without the mechanism that can. be used to advantage in a use of a pressure accumulator, or the like. press or ram, it being a general object of the in- It is a further object of the present invention vto l venton to, provide a mechanism of this characprovide a hydraulic mechanism operable to quick- 00 ter which overcomescertain diiiculties heretofore ly feed or advance to working position and then characteristic of mechanisms of this character operate under full pressure. The mechanism and to provide a construction and arrangement provided by the invention may be operated a subwhich is commercially practical: stantial distance, in fact, ,anyJ desired distance 19 Hydraulically actuated mechanisms such as until resistance is encountered, before the slow 65 rams, presses, etc., have had various undesirable heavy 'pressure characteristic of a hydraulic features that have materially interfered with press, or the like, is exerted. This-makes the their commercial development. For instance,l mechanism practical for use inxmanyv situations water hammer or ,pressure surge, such as occurs where hydraulic presses of ordinary construc- I inthe ordinary hydraulic mechanism, makes it tion cannot be used as no appreciable delay is in- 70 necessary to employ very heavy construction, and curred in bringing the press into engagement with in some cases'makes such mechanisms commerthe work. 1 cially impractical. Further, hydraulic mecha- A further object of the invention is to provide nisms such as I have mentioned are usually ema mechanism of lthe character mentioned oper- 20 ployed where it isdesired tol exert heavy pressure. able by gravity in a position where it is necessary 75 Hydraulically actuated cylinder and piston mechto operate under pressure. f

anisms are particularly adapted to this class of s AIt is another object of the present invention to work; however, such mechanisms have heretofore provide a hydraulic mechanism in which a cylbeen slow in operation or excessivelyy complicated inder and piston mechanism, or the like; is diand expensive of construction. For instance, the rectly connected with a constant delivery pump. 80 ordinary hydraulicpress of the cylinder and A further object of the invention is to provide piston type is operated from a source of presa mechanism in which a piston is allowed to fall sure which delivers liquid in small quantities and by gravity until resistance is encountered-whereat high pressures, with the result that the action upon it automatically continues in operationby of the mechanism, whether engaged in active pressure. f 4 85 work or not, is slow, Complicated and more or The various objects and features oi.' my invenless expensive constructions employing pressure tion will be best and more fully understood from accumulators have been tried with a view of the' following detailed description` of a typical overcoming the ditllculty just mentioned; how-' form and application of the invention, throghi ever, such mechanisms, in addition to being comout which description reference is had to the ac- 90 55 A further object of the invention is to provide lic ram or press, and-therefore I have chosen to 110 plicated and expensivea give trouble from water companying drawings, in which: e

hammer or pressure surge. Fig.`1 is a side view oi' a typical mechanism It isa general object of the. present invention embodying the invention showing the cylinder of to provide a hydraulic mechanism such as a the mechanism in section and the piston of the 40 press, orthe like, including a pump, the flow mechanism up, or unactuated. Fig. 2 is a view 95 oi' which is directed so that it performs useful of the cylinder and piston portion of the mechwork, or is by-palssed, and is thus continuous at anism showing the cylinder in section and the all times. By providing for-the continuous operpiston lowered or operated to a position suchas ation ofthe actuating pump, a pressure accumuit may operate to before resistance is encountered..

lator is eliminated and various features which Fig. 3' is a view similar to Fig. 2 showing the pis- 100 cause water hammer or pressure surge are ton at the lower end' of its stroke ready to be avoided. returned to the position shown in Fig. 1, and

4It is another object olf the present invention to Fig. 4 is an enlarged detailed sectional view of the provide a hydraulic mechanism in which the control, which isafeature oi.' the invention, showmoving element, say, for instance, a piston, can ing the parts positioned to correspond -to that 105- be operated under full control of the operator illustrated in Fig. 1. L 1` and without surging oi' pressures or actions such The present invention may be employed in hyas usually attendthe controlling of the movable draulic mechanisms oi various formsl or types, element of a mechanism of this character. however, it is particularly applicable to a hydrauy disclose it as applied to the cylinder and'piston type of press, it being understood that the broader principles of the invention are not to be construed as limited to the particular details herein set forth.

The mechanism illustrated includes, generally, a cylinder and piston mechanism A, fluid pressure supply means B, and a control C relating. the pressure supply means with the cylinder and piston mechanism A. The mechanism A includes, generally, a cylindrical body, or cylinder proper, 10, heads 11 and 12 closing the ends of the cylinder, and a piston 13 slidably carried in the cylinder 10 and attached to a rod 14 which projects from the cylinder 10through one of the heads. In accordance with the preferred form of the invention, the pistonis adapted to be actuated in .one direction, at least through a portion of its stroke, by' gravity, and preferably by gravity acting on the piston and its attached part or parts such'as the rod 14. In the preferred arrangement the cylinder body 10 is vertically disposed, as illustrated in the drawings, so that the piston which slides in its will drop or move downwardly by gravity.` In the drawings I have illustrated the cylinder body 10 supported by means of a suitable mounting or base 14B.

'It is to be understood that the outer or projecting end of the rod 14 may be related to the work or object tolbe pressed, for instance, it may be attached to a push rod 16 which actively engages the work. In the preferred arrangement the piston rod 14 projects downwardly through the lower head 12 of the cylinder. The present invention is not specically concerned with the manner in which the rod 14 is related to the work or object to be pressed, and therefore such detail has been omitted from the present disclosure. It will be obvious that various constructions used in presses, and the like, may be used with the present invention.

The iiuid pressure supply means may be varied in different forms or applications of the invention. For purpose of example, I have disclosed this means as including a pump 17 receiving fluid, say, for instance, water or oil, from a reservoir 18 through a pipe 19 and delivering it under pressure to a pipe 20 which conducts it to the control C. The pump 17 illustrated is of the rotary type and is shown driven by a belt 21. In the preferred arrangement the reservoir 18 is located above the pump 17 so that the oil flows to the pump by gravity.

The control C, which handles the oil delivered by the pump 17 so that the piston 13 is operated in the desired manner in the cylinder 10, includes, generally, a valve 22 controlling the supply of oil from the pump to the cylinder and the exhaust of oil Vf1`omthe cylinder, byl-passes 23 at the ends of the cylinderto 'conduct oil pased around the piston at the ends its stroke, and an auxiliary supply valve 24 for admitting or introducing fluid .into the cylinder upon the piston moving faster than it .is-.operated by normal action of the '.pump17.

..22 .and .24 are embodied in an assembly carried =by the upper cylinder head 1l. The assembly :carried .in 'the cylinder -head 11 includes a cylindrical valve cage 25 carrying the valve 22 which in Athis caseisin the Ynatu-reef a sleeve, and a core '.26 iitting Within the Avalve 22. 'The cylindrical cage 25 isformed integral with the head 11 and is arranged vertically as clearly shown in the drawings. The bore 27 of the cage 25 extends vertically through it. The lower -end of the cage `25 is closed or separated from the interior of the cylinder body 10 by a closure plate 28 while the upper end isclosed by a cover 29. The valve 22 is in the form ,of a sleeve slidably carried in the bore 27 of the cage `25 and is adapted to beoperated from a. lever 30 at the exterior ofthe construction through rods 31 extending through the cover 29, as clearly illustrated in Fig. 4. The core 26 is stationary 'in the cage 25 and fits the interior of the valve i 22.' In the construction shown the core 26 is tubular in form and is supported from its upper end to project downwardly into. the valve4 22.

Supply ports 32 are provided in the wall of the cage 25 communicating with the bore 27 and rethe cage 25 and communicate with the bore 27- at a point below the ports 32 and extend to the upper end of the cylinder 10. Cylinder ports 34 are formed in the cage 25 to communicate with the bore 27 at a point above the ports 32, the ports 34 being connected with the lower end of the cylinder 10 by a suitable manifold 35. An annular recess or port 36 is provided in the outer wall of the sleeve valve 22 tosconnect the ports 32 with the ports 33 when the valve 22 is down, as shown in Fig. 4 and to connect the ports 32 with the ports 34 when the valve is up. It will beobvious from inspection of Fig. 4 that communication between the

ports

32 and 34 is cut off when the valve 22 is down and that communication between the ports 32 and the ports 33 is cut off when the valve 22 is up.

In the particular ,construction illustrated the core 26 is hollow or tubular and communicates with an exhaust manifold 37 which projects upwardly from -the cover 29 and connects with the reservoir 18. 'I'he reservoir is located above the control C. A series of ports 40 is provided in the upper portion of the core 26. connecting the interior of the core with thespace between the. core and the bore 27, and a second series of 4ports 41 is formed through the wall of the core 26 at ay point opposite the port 32. The valve 22 is related to the various ports above described so that the ports 34 are opened or uncovered by the valve 22 to communicate with the ports 40 when the valve is down, connecting the ports 33 with the ports 32, while the ports 33 are uncovered by the valve and opened tothe 'interior ofthe core through the lower endof the core when the valve 22 is up connecting the ports 32 with the ports 34. With this relationing of parts, when huid under pressure is being Asupplied tothe upper end of the cylinder-10 through the ports 33, fluid below the piston is allowed to escape through the manifold 35, ports 34, ports 40, and manifold 37, and when fluid under pres- -sure is supplied to the, lower end 4of theAcylinder through the ports 34 and manifold 35 fluid above the piston is allowed to escape through the ports 33 through the lower end of the core 26 and through the manifold 37. 'Ihe ports 41 formed in the core 26 opposite the 'ports 32are designed to cooperate with ports 44 formed through the wall of the valve 22 so that part of the oil delivered to the ports 32 by the pump can be by-passed to the interior of the core 26 and thus exhausted to the reservoir 18 while the rest is conducted by the ports 33 to the upper end of the Cylinder. This construction provides for regulating or-contro1ling the speed with which the piston is forced downwardly in the cylinder.'

The auxiliary valve 24 when open as illustrated in Fig. 2 operates to admit iiuid into the cylinder above the piston when the piston drops by gravity at a rate faster than oil is supplied by the pump 17 to force the piston downwardly. Primarily the valve 24 controls communication between the reservoir 18, or other source of uid, and operates to admit fluid freely, for instance, by gravity, into the cylinder vabove the piston. In the particular form of the.invention illustrated the auxiliary valve 24 is arranged to admit uid by gravity to the cylinder above the piston, and, as above stated, the valve 24 is arranged in the assembly 'carried by the head 11 so that uid being exhausted from the lower end of the cylinder or iiuid from the reservoirimay flow downwardly through the core 26, through the lower portion of the valve cage 25, and into the upper end portion of the cylinder 10. In the case illustrated the valve 24 is in the nature of a puppet valve having a head 45 seating upwardly cna seat 46 surrounding an opening 47 formed through the plate 28 which closes the lower end of the cage 25. The head 45 is carried by a stem 48 operating in a guide 49. A spring 50 surrounds the stem 48 between the guide 49 and stop 51 on the upper end of the stem to normally yieldingly hold the valve up, or closed, as shown in Fig. 4. The valve spring is made so that the valve opens as soon as the piston 13 starts to fall or move downwardly inthe cylinder faster than it is forced down by the flu-id supplied by the pump 17. It will be obvious that the valve 24 continues to admit fluid from the exhaust side of the system, or-from the reservoir, directly into the top of the cylinder, until the downward movement of the piston is checked or slowed down as by the resistance of the work acting through the` n erate to allow continued circulation of fluid under action of .the pump 17- withoutoperation of the valve means to vreverse ory alter the direction'of 110W of the fluid. Each by-pass 'includes an outer port 52 and an inner'port. 53 communicating withthe interiorofthe cylinder 10, a connecting passage 54 between the ports, and a check valve 55 allowing the ilow in only one'directio through the passage 54. The

ports

52 and 53 are spaced apart longitudinal of the cylinder 10 a distance exceeding the length of the. piston, as will be apparent from Figs. 1, 2 and 3 of the drawings. The check valve 55 is arranged to allow flow from the inner port 53 to the outer port 52 and to check flow in the other direction. n

When the parts are in the position shown in Fig. 1 and pressure is admitted above the piston 13, the check valve 55 in the by-pass at the upper end of the cylinder prevents thefluid from bypassing the piston and thus causes the oil to act on the piston to force it downwardly in the cylinder. tion, that'is, the lowerV end of its stroke as shown in Fig. 3, the uid opens the check valve 55 in the by-pass at the lower end of the cylinder, allowing When the piston reaches the down posi-- flow around the piston so that the uid circulated I the lower end of its stroke andthe valve 22 is operated to circulate uid under pressure downwardly through the manifold 35 to the lower end of the cylinder, the check Valve 55 in the by-pass at the lower 'end of the cylinder is closed so that' the fluid introduced into the lower end of the cylinder forces the piston upwardly in the cylinder. It is to be noted thatthe piston rod 14 is very large in diameter and therefore occupies a substantial portion of the' cylinder area below the piston. Withr this construction the fluid delivered by the pump returns thepiston to the upper end of the cylinder quickly. i

kIt is believed that the features and operation of the mechanism will be fully understood from the foregoing description. In general, however, it may be stated that the pump 17 operates continuously and when the piston 1'3.is at the upper end of the cylinder and the valve 22 positioned as shown in Fig. 4, the piston starts downward movement in the cylinder and'will fall by gravity until the work or resistance is encountered. During the gravitational drop of the piston the auxiliary valve 24 opens as above described admitting Afluid into the upper end of the'cylinder above'thc piston at the same time that fluid -is being pumped into the cylinder above the piston through the ports 33. When the resistance or work is encountered, the valve 24 closes and the uid underiiuid delivered by the pump 17 to by-pass around under the piston 13 and out through the manifold 35. When it is desired to raise the piston or to return it to the upper end of the cylinder, the valve 22 is shifted so that the iluid under pressure is introduced under the piston through the manifold 35, which reversal of direction of flow causes the check valve in the by-pass at the lower end of nthe cylinder to close and the piston to move upwardly, the Aiiuid escaping from the upper end ofthe cylinder through .the ports 33 and the core 26. When the piston reaches the upper end of its stroke, the -check valve in the by-pass at the upper end of the cylinder automatically opens vallowing the uid circulated by/the pump 17 to water hammer. It is also to be particularly noted that the construction eliminates entirely a pressure accumulator or other corresponding element and thus provides a simple, inexpensive construction that is commercially practical.

In the drawings and in'the foregoing description I have disclosed inventions other` than the one claimed in this particular application; for

instance, the assembly including the

valves

22 and 24 is the subject of my cca/pending application entitled Valve, Serial No. 369,453, filed-June 8,

1929 (now Patent Number.1,855,433) in whichapplication this construction is set forth in detail` the specific details set forth, but wish to reserve to myself any changes or variations that may appear to those skilled in the art or' fall within the scope of the following claims.

Having described my invention, I claim:

1. In combination, a vertical cylinder, a piston operable in the cylinder, a fluid reservoir, a continuously operating pump, receiving fluid from the reservoir and delivering it under pressure, a fluid connection between the pump and the two ends of the cylinder and between the two ends of the cylinder and the reservoir, a reversible valve mechanism at the upper end of the cylinder and in said connection whereby the pumped fluid may be delivered to either end of the cylin.

der and allowed to escape from the other end of the cylinder to the reservoir so that the piston can be operated in either direction in the cylinder, and an auxiliary connection between the portion of said connection communicating with the reservoir and one end of the cylinder allowing fluid to enter said end of the cylinder at the same time that fluid is being delivered to said end of the cylinder by the pump. y

2.In combination, a cylinder, a piston operable in the cylinder, a fluid reservoir, a continuously operating pump receiving uid from the reservoir and delivering it under presseure, a uid connection between the pump and the two ends of the cylinder and between the two ends of th`e cylinder and the reservoir, a reversible valve in said connection whereby the pumped fluid may be delivered toeither end of the cylinder and allowed to escape from the other end of the cylinder to the reservoir, by-passes at. the ends of the cylinder allowing fluid to pass the piston at the ends of its stroke, and an auxiliary connection between the portion of said connection communicating with the reservoir and one end of the cylinder allowing fluid to enter said end of the cylinder at the'same time that fluid is being delivered to sald end of the cylinder by the pump.

3. In combination, a vertical cylinder, a piston operable in the cylinder, a fluid supply, a continuously operating pump receiving fluid from the fluidsupply, a valve supplied with uid by the pump and connected between the ends of the cylinder and the fluid supply operable to control delivery of pumped fluid to either end of the cylinder or to the uid supply, and an auxiliary fluid supply at the upper end of the cylinder delivering iluid to the cylinder upon the plston-moving faster than it ls operated by fluid from the pump.

4. In combination, a vertically disposed cylinder, a piston operable in the cylinder, a piston rod connected to the piston and projecting through the lower end ofthe cylinder, the rod being only slightly smaller than the cylinder, a fluid reservoir, a pump taking fluid from the reservoir, a valve at the upper end of the cylinder receiving fluid from the pump and directing it to the cylinder to reciprocate the piston therein, the valve controlling the exhaust of fluid from the ends of the cylinder to the reservoir and a fluid connection through the valve between the reservoir and the upper end of the cylinder allowing fluid tol enter the upper end of the cylinder from the reservoir upon the piston moving downwardly faster than it is operated by fluid from the pump.

5. In combination, a vertically disposed cylinder, a piston operable in the cylinder, a piston rod connected to the piston and projecting through the lower end of the cylinder, the rod being only slightly smaller than the cylinder, a fluid reservoir immediately above the cylinder, a pump taking fluid from the reservoir and delivering it to the cylinder to reciprocate the piston therein, and a fluid connection between the reservoir and the upper end of the cylinder allowing fluid to flow directly down and enter the lupper end'of the cylinder from the reservoir upon the piston moving downwardly faster than itis operated by fluid from the pump.

6. In combination, a vertically disposed cylnder, a piston in the cylinder, a piston rod connected with the piston and projecting from the lower end of the cylinder, a fluid reservoir above the cylinder', a pump taking fluid from the reservoir, and a control including a body on the upper end of the cylinder, a valve operable in said body to control the passage of fluid under pressure from the pump to the ends of the cylinder and to control the discharge of fluid from theends of the cylinder, there being a passage in said body to pass fluid from the reservoir into the upper end of the cylinder, and a normally closed valve in the said body controlling said passage adapted to open whenthe piston moves downwardly faster than it is operated by fluid under pressure supplied by the pump.

HARRY F. VICKERS.