US2900960A - Hydraulic control device - Google Patents

Description

Aug- 25, 1959 J. L. GRA'rzMUL-LER 2,900,960

HYDRAULIC `CONTROL DEVICE 'Filed Jan. s, 1955 s sheetssheet 1 LIIII' H .Il F u .M (IIL D: idw?. L

A118 25,4 1959 .1. L. GRATZMULLER 259005960 HYDRAULIC CONTROL DEVICE Filed Jan. s. 1955 3 Sheets-Sheet 3 l rya- United States Patent C The present invention relates to pressure fluid control systems whereby fluid under pressure is delivered in one direction for producing a desired effect and is discharged in another direction for exhaust or release.

In such control systems it is often desirable to reduce the time required for control valve operation and it is the main object of the present invention to provide an improved larrangement in which the desired time reducjtion for control -valve operation is obtained in a simple but `eliicient` manner.

It is a further object of the invention `to provide a pushbutton operated iluid ow control device to be inserted in the pressure line of a fluid motor to permit `flow of pressure fluid from a continuous fluid pressure source to one side of said motor while checking its return and to discharge fluid from said motor through said pressure line while checking the supply of pressure lluid from the source.

In carrying out the invention, two push button operated control valves are provided for controlling the i main fluidlilow control device, one of said pushbutton operated valves being adapted to control the `flow of pressure fluid from the source to a valve actuating memberof the main fluid ilow control device responsive to iluid pressure from said source and also responsive to fluid pressure from said fluid motor, and the other pushbutton operated valve being adapted to connect said fluid pressure responsive valve Iactuating member of the main ow control device with the exhaust, the arrangement being :such that a short manual or remote controlled opening of said one pushbutton operated control valve will subject the pressure responsive valve actuating mem- `ber of the main How control device to suilicient lluid pressure from the source to move said valve actuating member to a position in which said fluid motor is connected to the source, whereafter the lluid pressure conducted to the uid motor through the main ow control device will maintain said pressure responsive valve button operated control valve has been opened to connect the pressure responsive valve actuating member to the exhaust to thereby permit the valve actuating member to return into a position in which it connects the uid motor with the exhaust.

actuating member in said position until the other push- It is also an object of the invention to provide a pushi button operated fluid flow .,control device particularly adapted for controlling the operationrof, electric circuit i breakers having an operating piston one side of which `is subjected to therforce of resilient means and the other `side of which may-be subjected to uid` pressure 'adapted to move the piston against the action of said resilient means.

Other objects and advantages of the invention will be apparent from the following detailed description together with the accompanying drawings, submitted for purposes of illustration only and not intended to define the scope of the invention, reference being had for that purpose to the subjoined claims.

In these drawings:

Figure l is a general diagrammatical View of a hydraulic control device according to the invention,

Figure 2 diagrammatically shows such a hydraulic control device in its application to the control of a spring-loaded jack, A

Figure 3 shows the fluid low control device as applied to the control of a single acting hydraulic jack adapted to operate an electric circuit breaker.

` Referring to Figure l, there is shown `a hydraulic system adapted to deliver liquid under pressure in one direction for producing a desired effect, said system comprising a continuous liquid pressure source, e.g., a hydropneumatic accumulator 1, 1a utilization pressure line 2c leading to a Huid motor (not shown), and a low `pressure tank or reservoir 43.

The flow control device according to the invention `comprises a main ow control valve 9 having two movable valve members therein. The body of the main valve 9 is formed with two coaxial chambers, one of which constitutes a piston chamber and the other a valve chamber 53 provided with an inlet port connected to the `source 1 by a pipe 2a, an outlet port communicating lwith the pressure line 2c, and an exhaust port connected ,piston 8 slidably mounted in the piston chamber of valve 9 to divide said piston chamber into two compartments 46 and 47 of variable volume. The compartment 47 continuously communicates with the lowpressure container 43 throughV a duct 45. The compartment 46 may be communicated through pipes 48, 49, -50 with the source 1, under the control of a normally closed feeding valve 29, the opening of which is determined by triggering means diagrammatically shown in Figure l, in the form of a push-button 6a. The compartment `46 may be also communicated through pipes 48, 51, 52 under the control of a normally closed unloading valve 24, e.g. with the low-pressure container 43, through a duct 54, notfully shown in Figure l. The opening of the unloading valve 24 is determined by triggering means diagrammatically shown in Fig- `ure 1 under the shape of a push-button 15a. v

lvloreover, pipes 11, 5l, 48 permanently communicate i `the utilization circuit 2c with the compartment 450i the` l valve.. 9 and a owlimiting device; diagrammatically shown in Figure l in the form of a calibrated-hole35 `isinterposed in the said pipe ll, for the hereunder described purpose.

This ldevice operates as follows:

As soon as the push-button 6a is depressed; the feeding valve 29 is opened and the compartment 46 of the valve 9 is fed with pressure liq'uid from the source 1. Since the eifective area of lthe piston 3 of the differential piston assembly is greater than the effective area of the valve member 5, both said areas being acted upon by the same liquid pressure, the differential piston assembly is shifted from the unloading position to the feeding position. The utilization circuit 2c leading to a hydraulic jack H] is now fed with pressure liquid from the source .1, While piston Zblocks Communication betweenircilit 2c and the low-pressure container 43.

The vpipe 1i conducts pressure liquid from the i 1 tiliza tioncircuit 20, into the compartment '46 gthroughj' the pipes'Sl and' 4S, to` therebyrnaintain, in the said com partment, a liquid pressure sufficiently high to maintain the valve member in feedingposition."'From this moment, i.e. a short time after the feeding valve 29 has been actuated, this feeding valve may be'olosed again without causing interruption of the feeding of the utilization circuit. This condition persists until the push-button'lSa is depressed, which causes opening ofi the unloading valve Z4. The rate of the feeding ow 'of the compartment 46 from the utilization circuit 2c is limited byithe calibrated hole 35 and it will be easily understoodjthat 'if the relativecalibrations of the said hole` andthe evacualtion outlet controlled by theunloading valve 2li; is so caloulated that the rate of discharge through` the said valve v24 is higher than the rate `of feedingjthrough the said -ealibrated hole, Vthe liquid previously Containedin the Vcompartment lio will be evacuated through rthe pipes 52,

54. y--ln these conditions,` the piston S being no rnore -acted upon Vby any pressure, while the Valve member 5 continues to-be-subiected to the pressure of the source 1 in the space 53s, the differential piston assembly will be reset-into-unloading position, thus setting the utilization circuit-2c into communication with the container 43, while interrupting the feedingcornmunication between thelsource i and the said utilization circuit 2c.

In the embodiment-of `Figure 2, there isshown at l,

-as above, thesource of pressure liquid and at 2a, 2b,

2c, 2d, the feeding duct of a hydraulic jack 3, eg., pro- ,.vided to actuate a circuit-breaker, the following description being made with this assumption, it being well vunderstood-that the said jack 3 could controlany other mechanism as well; 4 is the piston of said jack; 5 is a 8, While designates a spring loading said piston; 6 is a circuit-making electro-magnet andis a Vcircuitbreaking electro-magnet.

In this embodiment, the control device according to the invention ensures a rapid evacuation of the liquid from the circuit-making jack 3, in spite of the limited action of the electro-magnet'i since it is possible to unload the .circuit-making jack 3 through an outlet of a section as -large as desired. Since, on lthe other hand, the ball valve 25 requires no 'lost motion before its opening, thevdevice `also ensures a short time-of response to the circuit-breaking order. Rod 26 between the ball valves 5 andZS ensures, when piston 8 is ysubjected to the l.liquidpressure from source 1 to close the ball valve 25, the opening of ball valve 5 while, conversely, when the piston 8 is `unboth valves 5 and Z5 are simultaneously opened.

=1oaded, the springV l() permits both opening of the ball i valve 25 and closing of the ball valve 5. The feeding rate of flow through .the deliveryV pipe 2a, 2b is preferably limited by means of a calibrated hole 27, to reduce the the yunwanted building-upV of .liquid pressnrb Q .L piston .8 whenball valve` 25 is in'unloadingpositionzliqnid 54' respectively.

sure'in/the feeding duct 2c `ofthe circuit-making-jaclg 3.

To the main ilow control valve 9 are connected, as in Fig. l, two independent feeding ducts; one of the said ducts 28a, 2811, 28e, controlled by a feeding valve 29 adapted to be triggered by the circuit-making electromagnet 6, ensures the building-up of the initial pressure for closing the valve 25 and opening the valve 5; the other feeding duct 11a- Mln ensures automatic sustaining of the said pressure, as long as the piston 8 is not unloaded. In this embodiment, non-return valves 30, 3E, the respective loading springs of which are shown at 32 and 33, are interposed between the feeding ducts 2gb, 28C and ila, lllb respectively, of the valve 9, to prevent liquid from counter-ilowing towards either feeding source. Thonon-return `valvell has vforits purpose to avoid, as the feeding valve 29 is triggered, any loss of time in the building-up, of the operative pressure below piston 8 whilethe non return valve 30 has the advantage of permitting to use a feeding valve 29, that may give rise toi slight leakages towards the ylow-pres sure. container without prejudice. tro-magnet l5 may be automatically controlled by a device 34 responsive to the pressure in the source 1, e.g., through a hydraulic system and electric circuits, not shown in Figurel. kFurthermorqthe pressure-responsive. devicefSfmayf. also. control a device prohibitingany y energizing of .the circuitmaling electro-magnet 6, when the .pressure inthe ysource i. is insufficient for thepurposes aimed at.

It will be ,easily understood that,v if the piston 8 is ,to be rapidly unloaded, as thecircuit breaking order., iswre- `ceiired` it isindispensable, that the feeding ofnithe said vided fan evacuation outlet controlled Vby aiylvalvepwS which is closed as valve 29 is opened, duedtonthe interpositionbetween both valvesof a pushing rod39.

. arrangement .haSifOrstS; purpose 10 V.Permit ,owilsaithe liquid container 43 of lealtages between the valve 9iand its seat, if any/,such leakages risking, otherwise,-,to ause fiowsthroughpipe 54 tocontainer 43,and duts55 56 provideI communication between i the chamberm containing valve 38, the chamber containing valve `Z4 andpipe .There isdiasrammaticallrhswn atall assess@ pressure-,responsive device,`perm itting the positionoflthe ]acl 3,V and hence, e.g., `thatof a circuit-breaker actuated thereby tobe, supervised by amere reading ofjthgpres- 'Ihis `last arrangement is `particularly v advantageou thecase ofthe control of a-circuit-brealier hydrau 1i ack. Referring toFig. 3, lhaveshownthe controlldeyice zas applied to. an .electric circuit .breaker column feornprising an upper tubularinsulator D provided fwith ,tivo vstationary contacts P1 and P2, alowentubularl. insulator T, .and a hydraulic jack Vamounted .between ,theeinsulatorsD and TI and having.its,pistonrodarranged-to cooperate with the .cpatacfs Pl, amLPltO maken, break an electriccrcuit. fighe contactsil andYPLareconnected `into the circuit by the conductors Cl andtz, respectively.

A springlp.,is. mounted in.the, cylinder of jack-yp to urge ythe Vpiston thereof, in a direction to ybreaktheeireuit nqiheinsnaor T imitated-.with a. riiuii maman which pressure liquid may be,. del i vered, tov lone ,Said piston, t0 mOi/@ theU laitsagainst fhefatiomo f 1in in a @gestion inaksithexsirrilit- Moreover, the circuit-breaking elec- The construction of the control device shown in Fig. 3 is similar to that shown in Figs. l or 2 and the same reference numerals as in Figs. l or 2 have been applied to like parts. The main iiow control valve 9 is connected to the continuous liquid pressure source 1 by pipe 2a, to the conduit K of insulator T by pipe 2d, and to the reservoir 43 by pipe 44 and the movable valve members 5 and 25 of the main flow control device 9 are adapted to selectively provide a passage for liquid ow from source 1 to one side of the operating piston of the circuit breaker, or a passage for liquid flow from said piston to reservoir 43.

Such a control system operates as follows:

When a circuit-making signal is received by the circuitmaking electro-magnet 6, the said electro-magnet is energized and lifts the movable valve member 29 of the feeding valve from its seat to permit the flow of pressure liquid from source 1 into the space of the main valve 9 below the pressure responsive valve actuating piston 8 thereof. The latter, thus fed with pressure liquid, opens against the action of the spring .10 and the feeding valve 5 and closes the unloading valve 25. From this moment, the source 1 sends liquid under pressure into the circuit-making jack Vp through the conduits 2a, 2b, 2c, 2d and K to move the piston of jack Vp against the action of the return-spring Rp to set the circuit-breaker into the circuit-making position, as shown in Figure 3. The pressure in the space of main valve 9 below piston 8 is maintained through the duct 11 and its calibrated hole so that the valve member is in open position. In these conditions, the circuit-breaker is held in circuitmaking position under the action of its jack Vp. This subsists as long as the piston 8 of the main valve 9 is not unloaded. The said unloading may be caused by the incoming into the circuit-breaking electro-magnet 1S Iof the circuit breaking signal. When thus energized, the said electro-magnet takes the valve member 24 of the unloading valve oli its seat, so that piston 3 of the main valve is permitted to move under the action of its spring 10 in a direction to bring valve member 25 into open, and valve member 5 into closed position. The pressure line 2c, 2d and K is then unloaded and the circuitbreaker set into circuit-breaking position by its spring Rp, which is no more opposed by any liquid pressure.

The position of the circuit-breaker is displayed on the control station, by means of the selective action of a Y pressure responsive device M1 on one of two visual indicators constituted, in the example shown, by a circuitbroken signal lamp Ld and by a circuit-made signal lamp Le. If the pressure of the source 1 is insuicient to ensure in the required conditions, the circuit-making stroke, an interlocking device, `not shown, actuated, if desired, from the pressure responsive device M2 prohibits any energizing of the circuit-making electro-magnet 15. Conversely, if the pressure of the source 1 becomes insuflicient to `maintain the circuit-breaker in circuit-making position, the said pressure responsive device M2 automatically causes energizing of the circuitbreaking electro-magnet 15, and hence, the operation of the circuit-breaker into safe current interrupting position.

There is shown at Z a valve adapted to maintain in the duct through which the liquid is evacuated from the circuit-making jack Vp towards the liquid container 43, a level ott liquid suiiiciently high to provide the required length of insulation corresponding to the voltage of the current` to be cut-off.

Finally, a pump P may be provided for feeding the source 1 from the liquid container 43.

It is clear therefore, `that the invention provides a ow control device that is in combination with a pressure line, a tank and a continuous iluid pressure source. Thls ow control device is inserted between the source and the pressure line and comprisesthe main body 9.

`maintains the valves 5 This body is provided with a first port means such as X in each iigure, first delivery conduit pipe portions such as 2a, 2b, between .the source and the port X, Figures 2 and 3 andpipe portion 2a in Figure l. The body 9 further has second port means such as Y, Figure l, `and the treble orices Y', Y, and Y in Figures 2 and 3. A second delivery conduit provides communication between the source 1 and this second port means. In Figure 1 this second delivery conduit is comprised by the pipe portion 50, the bore through the body containing valve 29, and pipe portions 49 and 41S. In Figure 2 the second delivery conduit is pipe or duct portions 2a, 28a, the bore through the body containing valve 29, pipe portion 28b, past valve 30 `and pipe portion 28C, into communication with the opening Y. Each form of the invention further includes means establishing communication between the pressure line and the second port means. In Figure 1 the duct or pipe portion 11, pipe portion S1 and pipe portions 51 and 48 provide for flow of fluid from the pressure line back to the body beneath the piston 8. In FigureZ, this communication is established by pipe portion 11a, past valve 31 and pipe portion 11b terminating at opening Y. The valve body further has a third port Z that is in communication. with the pressure line and an exhaust port EP. Means such as pipe portion 2c in each figure establish communication between the third port and the pressure line, whereas pipe 44 in Figures l and 3 and pipe 54 in Figure 2 provide communication between the `exhaust port EP and the tank 43. In addition, there is 4a communication established between the second port means and the tank. In Figure l this communication is by way of pipe portions 48 and 51 past valve 24 when open,rthrough the bore 52 and pipe portion 54 back to tank. In Figure 2 the communication is established past valve 24 when open,

past the opening Y" and the further opening Y, pipe portion 56, to the lower part of pipe 54" and thence to tank. A similar arrangement is incorporated in Figure 3. In the means that establishes the communication between the second port means and the pressure line is provided the permanent restricted passagel constituted by the apertured element 35. Within the body are movable valve means 5, 25, which selectively provide a first passage between the rst port means X and the third port Z and a second passage between the third port Z and the exhaust port EP. These valves are such that in the event of a pressure drop through the second port means, that is, a pressure drop beneath the piston 3, valve 5 will move` member, the piston S, is mounted in the body so that when :duid enters the body through the second port means, valve 5 isopened andV valve 25 is closed. The second delivery conduit has therein a first control valve 29 controlling ow of iiuid from the source 1 to the second port means Y, Fig. l and Y', Figures `2 and 3. A second control valve 24 is provided to connect the second-port means with the tank. In Figure l, when valve 24 is open, iiuid will flow from beneath the piston 3 through conduit portion 51 past valve 24, ball 52 through pipe 54 to tank. When valve 24 is opened in Figures 2 and 3, uid leaves the body through pipe S6, ows into pipe portion 44 (Fig. 3) and. 54' (Fig. 2) thence to tank. Both of these valves are normally biased to closed position, either hy the springs in Figure l or tluid pressure in the other two arrangements. Manually actuated operating means are provided to operate both of `the valves. This last-mentioned means being either the push buttons 6a and 15a or the button controlled solenoids 6 andl 15, in the` other figures. As pointed out previously, with both of closed, `pressure from the line flowing past the restriction 35 enters the body beneath the piston 8 and indeiinitely these control or triggering valves and `25 in the position in fwhich it 7 lf'as been previously brought, e.`g. the position shownY in Figures 2 and 3, wherein valve 5 is open and the Vrst passage through the body between inlet po-rt X and the third port vZ is open, so that pressure is exerted continuously from source 1 on the pressure line. This condition exists runtil valve 2.4 is opened, which occasions the pressure drop Vbeneath the piston 8, whereupon valve i sure liquid, feeding duct means between said source and said control jack and a container `at a pressure lower than that of said source, a hydraulic control device including a valve means in said feeding duct means between said source and said control jack andV controlling communication between said control jack and said source and between said control jack and said container respectively, a loaded hydraulic pilot jack operatively connected with said valve means and including a piston adapted, when fed with liquid under pressure, to move said valve means against the load to establish communication between said source and said control jack, feeding means including a iirst normally closed triggering valve means operable whenopen to feed said pilot jack with liquid from source during a short time, unloading means including a second normally closed triggering valve means operable when open to permit exhaust of liquid Ifrom said pilot jack, liquid conducting means downstream of said control device for placing said pilot jack in permanent communication with said feeding duct means, for maintaining feeding of the pilot jack for an indefinite duration after the closing of said iirst triggering valvemeans so as to maintain the circuit breaker in one of its circuit- Vmaking and circuit breaking positions, and means for limiting the rate of flow through said liquid conducting means to maintain the rate of flow therethrough lower than the rate of ldischarge through said second triggering valve means, whereby said pilot jack means can be completely unloaded during the time of operation of said triggering valve means so as to reset said circuit breaker into the other one of said two positions.V

2. In a hydraulic system as claimed in claim 1 and said hydrauliccontrol device including a valve casing, said valve means comprising two valve members located rwithin said casing, said valve members and said casing being constructed and arranged to establish the required communication withl said feeding duct means without any lost motion as soon as said valve members are actuated, and an operative mechanical connection between said valve members and the piston of said pilot jack to selectively cause immediate opening of one of sai-d valve members followed by closing of the other one as soon as said piston is actuated.

3. In a hydraulic system as claimed in claim 2 and each said valve member comprising a ball valve, said valve casing having a cylindrical passage therethrough communicating with said feeding duct means via said casing, a valve seat at each end of said passage for receiving said ball valves, said operative mechanical connection comprising a piston rod fast with the piston of said pilot jack and adapted to urge that ball valve that elements assuming s fading" valve @lass-sf, aus valve` casing having a cylindrical passage, and a port providing' communication between said passage and the feeding duct means downstream of the casing, through fluid ovvs into said control jack, said feediiig valve element comprising a ball cooperable with a seat provided at one end of said passage Vfor controlling municatio'n tosaid control jack, the other of said valve elements constituting an unloading valve element comprising the end of a rod fastwith the piston of said pilot jack, and a second rod freelyslidable vin said passage interposed between said valve elements and fast with said first rod, said rods constituting the` operative mechanical connection between said valve elements.

5. In a hydraulic system as claimed in claim 1 and a spring constituting the load on said pilot jack and` continuously urging the piston of said jack and said valve means toward the unloading position of the latter;

6. In a hydraulic system as claimed in claim 1 and further including a non-return valve interposed in said feeding duct means between said source and said pilot jack.

7. In a hydraulic system as claimed in claim 1 also including a non-return valve in said liquid conducting means between the means limiting the return of flow therethrough and said pilot jack.

8. In a hydraulic system as claimed in claim 1 and including a non-return valve interposed in said feeding duct means `between said source and said pilot jack and another non-return valve interposed in said Vliquid coriducting means between the means limiting the How therethrough and said pilot jack.

9. In a hydraulic system as claimed in claim a push button operatively connected with at least one orf said normally closed triggering valve means so as to permit opening thereof during a short time.

10. In a hydraulic system as claimed in claim 1 and an electro-magnet operatively associated with at least one of said 'normally closed triggering valve means and operable to open the same during a short time.

ll. In a hydraulic control system as claimed in claini l and also including means operatively associated with said second triggering valve means and operable responsive to pressure in said source to actuate said second triggering valve means in response to a predetermined pressure in said source.

12. The combination with a pressure line, a tank and a continuous uid pressure source for delivering uid under pressure to said line, of a flow controlV device to be inserted between said source and said pressure line and comprising a body having a first port means, a Yfirst delivery conduit providing communication between said source and said first port means, said body further having second port means, a second deliveryy conduit providing communication between said source and said second port means, means establishing communication between said pressure line and said second port means, a thirdA port communicating with said pressure line and an exhaust port, means establishing communication between said exhaust port and said tank, means establishing communication between said second port means and said tank, means providing a permanentv restricted passage in the means establishing communication between said second port means and' said pressure line, movable valve means arranged in said bodyV to selectively provide a first passage between said rst port means and said thirdl huid pressure entering saidvbody throughv said second port meansto thereby close said second passage and to open said first passage, a first control valve in said second delivery conduit for controlling the flow of uid from said source to said second port means, a second control yValve adapted to connect said second port means with said tank, said rst and second control valves being normally biased to closed position, and manually actuated operating means adapted to operate each of said rst and second control valves to open position, whereby with both said control valves closed pressure through said restricted passage indefinitely maintains said movable valve means in a position to pros/ide a passage between said irst port means and said third port to provide communication between said source and said pressure line 10 until operation of said second control valve means to open position.

References Cited in the file of this patent UNITED STATES PATENTS 1,947,191 Davis et al. Feb. 13, 1934 2,231,708 Dutling Feb. 11, 1941 2,308,261 Bartlett et al. Jan. 12, 1943 2,314,398 Hoch Mar. 23, 19,43 2,430,128 Levstrup Nov. 4, 1947 2,464,237 Kelle Mar. 15, 1949 2,473,687 Kershaw June 21, 1949 2,491,112 Janssen Dec. 13, 1949 2,514,747 Daniels July 11, 1950

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