US3373843A

US3373843A - Flow and pressure control valve

Info

Publication number: US3373843A
Application number: US540006A
Authority: US
Inventors: Herbert H Schmiel; Louis G Hajma
Original assignee: Parker Hannifin Corp
Current assignee: Parker Hannifin Corp
Priority date: 1966-04-04
Filing date: 1966-04-04
Publication date: 1968-03-19
Anticipated expiration: 1985-03-19
Also published as: GB1156272A; DE1600887A1; FR1517538A; NL6704753A

Description

Mam}! 1963 H. H. SCHMIEL ETAL mow AND PRESSURE CONTROL VALVE 3 Sheets-Sheet 1 Filed April 4, 1966 3 mm MM 5 ms H m E B Lou/s a HAJMA ATTORNEYS March 19, 1968 H H. s HMI ETAL 3,373,843

- FLOW AND PRESSURE CONTROL VALVE Filed April 4, 1966 5 Sheets-Sheet I9 20 I F v INVENTORS m HERBERT H. .Sc

Laws 6. HAJMA ATTORNEYS March 19, 1968 H, H- s M T L 3,373,843

FLOW AND PRESSURE CONTROL VALVE Filed April 4, 1966 3 Sheets- Sheet 3 2 I l 2 2 S 7 3 5 Me. n ww 2 w 3 mL 2 w 47/? 6 6 .ME I W A I M SA A u j o .m I ,HH 6 E a /U m m 8 t 2 //%//W 9 m 2 $34 WW 7 IT 5 am EL 1 5 w w H I 7 2 Y J m m M 5 m 8 pm w v 6 7 98 5 0 U W m A M 1$ \ka m I JV,

ATTORNEYS United tates Patent Ofifice 3,373,843 FLOW AND PRESSURE CONTROL VALVE Herbert H. Schmiel, Cleveland, and Louis G. Hajma,

Warrensville Heights, Ohio, assignors to Parker Hannifin Corporation, Cleveland, Ohio, a corporation of Ohio Filed Apr. 4, 1966, Ser. No. 540,006 24 Claims. (Cl. 182141) The present invention relates generally as indicated to a flow and pressure control valve and more particularly to a valve assembly for use as with a personnel lift device of the type comprising a truck-mounted boom having one or more buckets for personnel engaged in overhead electrical work, tree trimming, fruit harvesting etc.

A typical aerial lift device of the character referred to comprises a truck having a lower boom mounted thereon for swinging about vertical and horizontal axes, and an upper boom pivotally connected to the tip of the lower boom for pivotal movement about a horizontal axis, said upper boom having a bucket or basket assembly mounted at its tip.

It is a primary object of this invention to provide a dual control system for an aerial lift device or the like in which there are duplicate directional control valves mounted respectively on the truck and on the tip of the upper boom arranged for selective operation by a workman on the truck or by a workman standing in the bucket for controlling the position of the latter by raising, or lowering or swinging of the booms.

It is another object of this invention to provide on the truck-mounted directional control valve assembly a selector valve which in one position conducts fluid under pressure solely to the directional control valve thereof .and which in another position conducts fluid under pressure solely to the bucket-mounted directional control valve.

It is another object of this invention to provide on the bucket-mounted directional control valve assembly a selector valve which in one position conducts fluid under pressure solely to the directional control valve thereof and which in another position conducts fluid under pressure solely to a port or ports to which power operated implements such as cable cutters, pruning shears, saws, etc. are adapted to be connected.

It is another object of this invention to provide a truckmounted control valve assembly in which the aforesaid selector valve thereof has a relief valve contained therewithin to relieve excess pressure in the system whether the various fluid motors are under the control of the truckmounted valve assembly or the bucket-mounted valve assembly.

It is another object of this invention to provide a bucket-mounted control valve assembly in which the aforesaid selector valve thereof has a flow control valve contained therewithin to control the rate of flow of fluid to the directional control valve in said one position of said selector valve and to the implement port in said another position of said selector valve.

It is another object of this invention to provide a bucket-mounted control valve assembly in which the aforefluid to the directional control valve thereof is adjustable over a wide range from a mini-mum as determined by a fixed orifice and a closed regulator valve to a higher value as determined by such orifice and the extent of opening of the regulator valve (maximum flow when regulator valve fully open).

It is another object of this invention to provide a relief valve in the bucket-mounted valve assembly which is responsive only to predetermined build-up of pressure in the implement or tool circuit, the relief pressure thereof generally being substantially less than employed in the 3,373,843 Patented Mar. 19, 1968 boom manipulating circuits not only because of smaller loads but also because it is desired to maintain flexibility in the flexible hoses leading to the power operated tools.

It is another object of this invention to provide a foolproof connection between the truck-mounted and bucketrnounted control valve assemblies so that in the event of inadvertent actuation of a directional control valve of the latter no swinging or lowering of the boom will occur.

Other objects and advantages of the present invention Wlll become apparent as the following description proceeds. i

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawlng setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

FIG. 1 is a perspective view of a typical aerial lift device having a boom assembly mounted on a truck and having mounted on the 'tip of the boom assembly a pair of buckets or baskets for workmen, and having a control valve assembly associated with the truck and with the basket respectively;

FIGS. 2 and 3 are cross-section views of the respective gluck-mounted and basket-mounted control valve assemres;

FIG. 4 is a fragmentary cross-section view on enlarged scale illustrating the internal construction of the selector valve of the truck-mounted valve assembly (the first spool at the left in FIG. 2);

FIG. 5 is a fragmentary cross-section view on enlarged scale illustrating the internal construction of the selector valve of the basket-mounted valve assembly (the first spool at the left in FIG. 3); and

FIG. 6 is atransverse cross-section view taken along line -6-6, FIG. 5.

Referring now more particularly to the drawings, and first to FIG. 1, the aerial lift device herein illustrated by way of example, comprises a boom assembly 1 includlng a lower boom 2 mounted on the horizontal pivot 3 of the swing member 4 which will be mounted for swingmg about a vertical axis, an upper boom 5 which is pivotally mounted at 6 to the tip of the lower boom 2 for swinging of the upper boom 5 in a vertical plane, and a pair of

baskets

7, 7 mounted on the tip of the upper boom 5. As shown in FIG. 1, the lower boom 2 will be raised and lowered about the pivot 3 by operation of the fluid motor 8 and the upper boom 5 will be raised and lowered about the pivot 6 by operation of the fluid motor 9. Mounted in the base 10 of the boom assembly 1 as a part of the truck 11 is the truck-mounted control valve assembly 12, and mounted on the tip of the upper boom V tional control valves will be provided for operating other fluid motors (not shown) for eifecting swing of the boom assembly 1, for extending and retracting the outrigger struts 15, etc.

Referring to the truck-mounted valve assembly 12 as shown in FIGS. 2 and 4, the same comprises a housing 16 having

bores

17 and 18 in which the

respective valve spools

19 and 20 are reciprocable, said

bores

17 and 18 being intersected axially therealong starting at the middle by a bypass passage 21 which has its upstream end intersecting another bore 23 in said housing 16 and which has its downstream end leading to the return port 24 of the housing 16 which is adapted to be connected by the conduit 25 to a tank 26; by pairs of

pressure feed passages

27, 27 and 28, 28 which straddle the aforesaid bypass passage 21 and which have load check valves 29 therein for purposes well known in the art, the circuit herein shown for purposes of illustration being of the parallel type, whereby the

spools

19 and 20 may be operated independently or simultaneously; by pairs of

motor passages

30, 30 and 31, 31 adapted for connection with the respective motors 8 and 9 for manipulating the lower and upper booms 2 and and by a pair of

return passages

32, 32 which lead to the aforesaid return port 24.

In FIG. 2 the spools 19 and are shown in neutral position whereby the bypass passage 21 is open from its upstream end to its downstream end and as apparent, when the

spools

19 and 20 are separately or simultaneously moved up or down from neutral position, the bypass passage 21 is closed and the associated pressure feed passage 27 and/ or 28 is communicated with the adjacent motor passage and/or 31 to control operation of the respective motor 8 and/ or 9, the displaced oil being returned to the tank 26 by way of the motor passage 30 and/ or 31 then in communication with the adjacent return passage 32.

The two-spool directional control valve assembly 15 just described is of more or less conventional type except that the upstream end of the bypass passage 21 instead of being connected directly with a pressure inlet port 34, intersects the bore 23 in which a selector valve spool 35 is movable.

As best shown in FIG. 4, the selector valve spool 35 has screwed into the upper end thereof a detent carrier 36 which has detent balls 37 biased as by spring 38 into engagement with one of the

grooves

39 or 40 of a detent sleeve 41 which is held by cap assembly 42 screwed into the housing 16. The upper end of the selector valve spool has a relief valve 43 therein comprising a seat member 45 which is engaged by the relief valve member 46, the latter being biased by the spring 47 compressed between said valve member 46 and the adjustable valve guide and spring follower 48. The guide 48 has threaded engagement in the detent carrier 36 and when the cap assembly 42 is removed, the compression of the spring 47 may be adjusted by turning the spring guide 48 in either direction and locking it in adjusted position by tightening the locknut 49. As evident, when the fluid pressure within the seat member 45 acting on the exposed area of the relief valve member 46 exceeds the force exerted by the spring 47, the relief valve member 47 will be forced upwardly away from the seat member to permit the relief of such excess pressure which flows through the openings 50 into the return passage 32 via the branch return passage 51.

When the selector valve spool 35 is moved down to its other position with the detent balls 37 engaged in the lower groove 40, the openings 50 will yet be in communication with the branch return passage 51 to relieve fluid pressure in excess of the setting of spring 47.

When the selector valve spool 35 is in its upper position as shown in FIGS. 2 and 4, fluid under pressure discharged by the pump 52 flows through the conduit 53 to the inlet passage 34 which intersects the bore 23 and such fluid under pressure passes through the

openings

54 and 56 in the selector valve spool 35 to the upstream end of the bypass passage 21, whereby the spools 19 and/ or 20 may be operated in normal manner to manipulate the respective fluid motors 8 and/ or 9 for raising or lowering the booms 2 and 5. In this upper position of the selector valve spool 35, the passage 57 is blocked, said passage 57 being connected by conduit 58 to the inlet passage 59 of the basket-mounted valve assembly 14. When the selector valve spool 35 is shifted to its down position with the detent balls 37 engaged in the lower groove 40, the land 60 closes the upstream end of the bypass passage 21 and the land 61 uncovers the 4 passage 57 for flow of fluid from the inlet passage 34 to said passage 57 via the

holes

54 and 62 in the selector valve spool 35, and as before-mentioned, the relief valve assembly 43 determines the maximum pressure in the entire system irrespective of the position of the selector valve spool 35,

Now, going to the basket-mounted valve assembly 14 as shown in FIGS. 3 and 5, it comprises a housing 70 much like the housing 16 of the truck-mounted valve assembly 12, that is, it also has

spools

19 and 20 therein to control the respective motors 8 and/ or 9 and therefore that part of the valve assembly 14 has been shown in elevation and the description thereof need not be repeated. v

The basket-mounted valve assembly 14 also has a bore 23 in which a selector valve spool 71 is movable to either of two detent held positions, the detent mechanism being similar to that described in connection with the truck mounted valve assembly 12, i.e., comprising a detent carrier 36 screwed into the upper end of the selector valve spool 71 and carrying spring-biased detent balls 37 which engage yieldably in either the upper or

lower groove

39 or 40 of the detent sleeve 41 which is held by the cap 72 screwed into the valve housing 70.

The bore 23 is axially intersected therealong by an inlet passage 59 which receives fluid through the conduit 58 from the truck-mounted valve assembly 12 when the selector valve spool 35 in the latter is in its lower position; by the upstream end of the bypass passage 21; by the inlet and

outlet passages

73 and 74 of a needle or regulator valve 75; and by return passages 32 and branch return passage 51.

In the upper end of the selector valve spool 71 is a flow control valve member 76 which is biased by the spring 78 to the position shown but which moves upwardly to increasingly uncover the openings '79 which communicate with the return branch passage 51 as the pressure increases.

When the selector valve spool 71 is in its u er posi tion as shown in FIGS. 3 and 5, and with fluid flowing to the inlet passage 59 via the conduit 58, such fluid passes through the openings 80 in the selector valve spool 71- and flows through the orifice 81 into the upstream end of the bypass passage 21 and at the same time the fluid coming into the inlet passage 59 flows to the inlet passage 73 of the needle valve 75 and therepast to the needle valve outlet passage 74 also to the upstream end of the bypass passage 21 via the flats 82 on the selector spool 71. Thus there is available for actuating either or both of the motors 8 and 9 a predetermined amount of fluid flow which is the sum of the flow through the orifice 81 and the adjustable orifice provided by the needle valve 75. For example, the orifice 81 may have a capacity of say, 4 gallons per minute which would be the minimum flow when the needle valve 75 is closed. The flow therefore can be varied from say, 4 gallons per minute minimum up to 12. gallons per minute maximum which would be available for motor actuation when the needle valve 75 is in its fully open position. Of course, any desired flow between minimum and maximum is made available by adjustment of the needle valve 75, the needle 83 of which is threaded in the bushing 84 and which has a locknut 85 for locking the needle 83 in any desired adjusted position.

From the foregoing, it can be seen therefore that when the selector valve spool 35 of the truck-mounted valve assembly 12 is in its lower position, a workman in the basket 7 may, when the selector valve spool 71 of the basket-mounted valve assembly 14 is in its upper position, manipulate either or both of the spools 19 and/ or 20 for operating the lower and upper booms 2 and 5 so that he may position the basket 7 as desired.

The basket-mounted valve assembly 14 has an implement or tool pressure passage 86 intersecting the selector valve spool bore 23 and desirably the housing 70 will be provided with a quick disconnect coupling -(not shown) for releasably engaging a complemental coupling provided on the flexible hose 87 of the power operated tool 89 which herein by way of example, is shown as comprising pruning shears for cutting tree branches or limbs, and by way of example, such pruning shears 89 may comprise a single acting fluid motor 90 so arranged that it is actuated in one direction to close the shear blades when there is fluid pressure in hose 87 admitted into motor 90 by manipulation of a 3-way valve 91 or the like. When the 3-way valve 91 is released it moves to the FIG. 3 position and a spring (not shown) in the motor 90* or in the shear linkage actuates the motor 90' in the opposite direction to open the shear blades. The return oil from motor 90 returns through a flexible hose 92to the port 93 of housing 70 which leads to return port 24 of housing 70. It is to be noted-that the return port 24 of housing 70 is connected by conduit 94 to the passage 95 of housing 16, the passage 95 intersecting bore 23 of housing 16 between the return passage 32 and the return branch passage 51. Thus, when the selector valve spool 35 is in the position shown in FIGS. 2 and 4 the workman in the basket 7 cannot lower the booms 2 and 5 by inadvertent movement of the

spools

19 and 20 of valve assembly 14 to a position draining the motors 8 and 9 and, of course, the booms 2 and 5 cannot be raised at the time because the passage 57 is blocked by selector valve spool 35. When the selector valve spool 35 is in its down position, fluid displaced by motors 90, 8, and 9 is returned to the tank 26 through conduit 94 and the

passages

95 and 51 which are then in fluid communication with each other.

When the selector valve spool 71 is moved to its down position with the detent balls 37 engaged in the lower groove 40, the flow of fluid through orifice 81 and through the flats 82 is cut off from the upstream end of bypass 21, and the spool land 96 cuts 0E the inlet passage 59 from the needle valve inlet passage 73* whereby the

spools

19 and 20 of valve assembly 14 are rendered inoperative to manipulate the motors 8 and 9. When the selector valve spool 71 is thus shifted downward the openings 97 and the flats 82 provide fluid communication between the pressure inlet passage 59 and the implement pressure passage 86 so that the power tool 89 may be actuated by operating valve 91.

When the pressure drop through opening 97 exceeds a desired value, the pressure in spring chamber 98 through opening 99 and

passages

100, 101, and 74 will be suficiently lower than the pressure acting on the underside of valve 76 to cause compression of spring 78 and consequent upward movement of valve 76 to uncover openings 79 leading to the return branch passage 51. In this way, rate of flow of fluid to motor 90* is controlled.

When the selector valve spool 71 is in such lower position the openings 102 will register with return passage 32 whereby excess pressure in the tool pressure circuit will be relieved by movement of relief valve member 103 against spring 104 away from the seat 105. Pressure in the tool circuit passage 86 acts on the relief valve member 103 through openings 106 in the flats 82. As previously mentioned, it is desired to limit the pressure at which the power tool 89 is operated to about one-half that used for boom actuation which is adequate for performing branch or limb cutting operations, branch sawing, cable cutting, or other comparable operations while yet the

hoses

87 and 92 may be quite flexible under such lower pressure to facilitate manipulation of the tool 89'. Generally a pressure of about 2,000 p.s.i. is employed for actuating the boom control motors 8 and 9. In that case, the relief valve 43 in the selector valve spool 35 will be set for opening at pressures exceeding 2,000 p.s.i. while the relief valve 103- will be set for opening at pressures exceeding 1,000 p.s.i.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as our invention:

1. A fluid power control system comprising first and second valve assemblies having pressure inlet passages and motor passages, and first and second directional control valve members selectively movable in the respective assemblies to control fluid pressure actuation of a motor comunicated with said motor passages; first and second selector valve members movable in the respective valve assemblies from one position communicating the respective inlet passages with the respective directional control valve members to another position in which the inlet passage of said first valve assembly is communicated with the inlet passage of said second valve assembly and in which the inlet passage of said second valve assembly is communicated with another motor passage thereof.

2. The system of claim 1 wherein said first valve assembly has a first. return passage for connection with a tank; and wherein said second valve assembly has a second return passage communicating with a passage leading to said first selector valve member, said second return passage being closed and opened to said first return passage when said first selector valve member is in said one and another position respectively.

3. The system of claim 1 wherein said first selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof in said one and another position of said first selector valve memher.

4. The system of claim 1 wherein said second selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof when said second selector valve member is in said another position.

5. The system of claim 1 wherein said first selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof in said one and another positions of said first selector valve member; and wherein said second selector valve has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof when said second selector valve is in said another position, the relief valve in said second selector valve member opening at a lower fluid pressure than the relief valve in said first selector valve member.

6. The system of claim 1 wherein said second selector valve member has a flow control valve therein which, when said second selector valve member is in said one position, establishes predetermined flow of fluid from the inlet passage thereof to said second directional control valve member.

7. The system of claim 6 wherein the flow of fluid from the inlet passage of said second valve assembly to said second directional control valve member in said one position of said second selector valve member is the sum of the flows through a fixed orifice and an adjustable needle valve in said second valve assembly.

8. The system of claim 7 wherein said flow control valve conducts fluid flow in excess of such predetermined flow to a return passage in said second valve assembly.

9. A valve assembly comprising a housing having an inlet passage for connection with a fluid pressure source, outlet passages for connection with pressure utilization devices, and a return passage for connection with a tank; a directional control valve member movable in said housing selectively communicating one outlet passage with either said inlet passage or with said return passage; and a selector valve member movable in said housing from one position to another position alternately opening and closing said inlet passage to said directional control valve member and closing and opening said inlet passage to another outlet passage.

10. The assembly of claim 9 wherein said selector valve member has a relief valve therewithin opening to said return passage when the fluid pressure in said inlet passage exceeds a predetermined value.

11. The assembly of claim 9 wherein said selector valve member has a relief valve therewithin opening to said return passage when the fluid pressure in said inlet passage exceeds a predetermined value, said relief valve being thus opened in both positions of said selector valve member.

12. The assembly of claim 9 wherein said selector valve member has a relief valve therewithin opening to said return passage when the fluid pressure in said inlet passage exceeds a predetermined value, said relief valve being thus opened only when said selector valve member is in said another position.

13. The assembly of claim 9 wherein said housing has another inlet passage which is open to said return passage only When said selector valve member is in said another position.

14. The assembly of claim 9 wherein said selector valve member has a flow control valve therewithin which, when said selector valve member is in said 'one position, opens said inlet passage to said return passage when the rate of flow of fluid to said directional control valve member exceeds a predetermined value.

15. The assembly of claim 9 wherein the rate of flow of fluid from said inlet passage to said directional control valve member in said one position of said selector valve member is the sum of the flows through a fixed orifice and an adjustable needle valve in said housing.

16. The assembly of claim 9 wherein the rate of flow of fluid from said inlet passage to said directional control valve member in said one position of said selector valve member is the sum of the flows through a fixed orifice and an adjustable needle valve in said housing; and wherein said selector valve member has a flow control valve therewithin which, when said selector valve member is in said one position, opens said inlet passage to said return passage when the rate of flow of fluid to said directional control valve member exceeds a predetermined value.

17. A fluid power control system for an aerial lift device of the type having a base, a boom and bucket assembly movably connected to said base, and a fluid motor operative to raise and lower said boom and bucket assembly; said system comprising first and second valve assemblies operable respectively at said base and at said bucket, and each having a pressure inlet passage and a motor passage for connection with said fluid motor; first and second directional control valve members selectively movable in the respective valve assemblies to control fluid pressure actuation of said fluid motor; first and second selector valve members movable in the respective valve assemblies from one position communicating the respective inlet passages with the respective directional control valve members to another position in which the inlet passage of said first valve assembly is communicated with the inlet passage of said second valve assembly and in which the inlet passage of said second valve assembly is communicated with another motor passage thereof, said another motor passage of said second valve assembly being connected with the fluid motor of a power tool adapted to be manipulated by a workman in said bucket.

18. The system of claim 17 wherein said first valve assembly has a first return passage for connection with a tank; and wherein said second valve assembly has a second return passage communicating with a passage leading to said first selector valve member, said second return passage being closed and opened to said first return passage when said first selector valve member is in said one and another positions respectively.

19. The system of claim 17 wherein said first selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof in said one and another positions of said first selector valve member.

20. The system of claim 17 wherein said second selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage there of when said second selector valve member is in said another position.

21. The system of claim 17 wherein said first selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof in said one and another positions of said first selector valve member; and wherein said second selector valve member has a relief valve therein which is opened by excess fluid pressure in the inlet passage thereof when said second selector valve member is in said another position, the relief valve in said second selector valve member opening at a lower fluid pressure than the relief valve in said first selector valve member.

22. The system of claim 17 wherein said second selector valve mem er has a flow control valve therein which, when said second selector valve member is in said one position, establishes predetermined flow of fluid from the inlet passage thereof to said second directional control valve member.

23. The system of claim 22 wherein the flow of fluid from the inlet passage of said second valve assembly to said second directional control valve member in said one position of said second selector valve member is the sum of the flows through a fixed orifice and an adjustable needle valve in said second valve assembly.

2 The system of claim 23 wherein said flow control valve conducts fluid flow in excess of such predetermined flow to a return passage in said second valve assembly.

References Cited UNITED STATES PATENTS 6/1960 Richey 1822 11/1964 Gasquet et al. 137-344 REINALDO P. MACHADO, Primary Examiner.

Claims

17. A FLUID POWER CONTROL SYSTEM FOR AN AERIAL LIFT DEVICE OF THE TYPE HAVING A BASE, A BOOM AND BUCKET ASSEMBLY MOVABLY CONNECTED TO SAID BASE, AND A FLUID MOTOR OPERATIVE TO RAISE AND LOWER SAID BOOM AND BUCKET ASSEMBLY; SAID SYSTEM COMPRISING FIRST AND SECOND VALVE ASSEMBLIES OPERABLE RESPECTIVELY AT SAID BASE AND AT SAID BUCKET, AND EACH HAVING A PRESSURE INLET PASSAGE AND A MOTOR PASSAGE FOR CONNECTION WITH SAID FLUID MOTOR; FIRST AND SECOND DIRECTIONAL CONTROL VALVE MEMBERS SELECTIVELY MOVABLE IN THE RESPECTIVE VALVE ASSEMBLIES TO CONTROL FLUID PRESSURE ACTUATION OF SAID FLUID MOTOR; FIRST AND SECOND SELECTOR VALVE MEMBERS MOVABLE IN THE RESPECTIVE VALVE ASSEMBLIES FROM ONE POSITION COMMUNICATING THE