US3699993A

US3699993A - Control valve for the flow to and from a variable pressure chamber

Info

Publication number: US3699993A
Authority: US
Inventors: Erich Hemon; Erich Ruchser
Original assignee: Technomatic AG
Current assignee: Technomatic AG
Priority date: 1970-05-06
Filing date: 1970-12-31
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24
Also published as: GB1291507A; ES195163Y; CH509535A; ES195163U; JPS4919293B1; FR2066747A5

Abstract

A control valve has two valve pistons disposed on opposite sides of a straight passage which is connected at one end with an expanding and contracting pressure chamber of a hydraulic press or brake system, and has a discharge opening at the other end. The valve pistons have a first position in which fluid from the contracting pressure chamber can flow with minimal resistance through the straight passage and out of the discharge opening. In a second position of the valve pistons, the discharge opening is closed by the same, and pressure fluid can be supplied from an inlet through control valves into the straight passage and from there to the expanding pressure chamber.

Description

United States Patent Herion et a].

AND FROM A VARIABLE PRESSURE I, CHAMBER.

inventors: Erich Herion, Stuttgart; Erich Ruchser, Stetten/Remstal, both of Germany, Assignee: Technomatic AG, Aesch/Luzern,

Switzerland 7 Filed: Dec. 31, 1970 Appl. No.: 103,222

Foreign Application Priority Data Oct. 24, 1972 3,139,109 6/1964 Ruchser ..91/424 905,585 '9/1962 Great Britain ..l37/l02 Primary Examiner-Edgar W. Geo ghegan Assistant Examiner-'Barry Gros'sman Attorney-Michael S. Striker [57] ABSTRACT A control valve has two valve pistons disposed on op- May 6, 1970 Switzerland"; .26935/ I June 30 1970 Switzerland .9953/70 Passage whch at one end wlth an expandmg and contracting pressure chamber of a hydraulic press or brake system, and has U.S. Cl. ..137/l02, 91/424, 9911/2362; 7 a discharge opening at the other end The valve Int Cl Gosd 7/00 Flsb 11/08 pistons have a first position in which fluid from the Fie'ld H07 102 51/424 442 contracting pressure chamber can flow with minimal g 1 resistance through the straight passage and out of the discharge opening. In a second position of the valve References Cited pistons, the discharge opening is closed by the same, I and pressurev fluid can be supplied from an inlet UNITED TES TE S through control valves into the straight passage and 3 419 30 0/ 96 G t n /1 from thereto the expanding W' chamberra mu er 12/ 1920 Stage", ..91/468 22 Claims, 12 Drawing Figures H v ii;= Hi": H

a0 86 as 0 62 90 PATENTEU 24 I973 3,6 99 .993

SHEU 2 OF 7 FIG. 4

INVEVTDR, ERR-u Hal/0m y Ellen IZULHSEA PATENTEDHET 2 I 12 a, 699 .999

SHEET 5 OF 7 mmvmz PATENTEDHBI 24 I972 FIG. 77 56 SHEET 7 (IF .7

" INVENTOR.

emu flew/0m Ema Bum- 5L CONTROL VALVE FOR THE FLOW TO AND FROM A VARIABLE PRESSURE CHAMBER I BACKGROUND OF THE INVENTION trol position retracted fromthe straight passage so that fluid from the pressure chamber flows through the straight passage and directly out of the discharge opening, and a second control position located in the movable toward and away from each other. The valve pistons have closure pieces provided with longitudinal and transverse bores, through which a pressure fluid is supplied to'a consumer apparatus after several deflections If this known control valve is shifted from the operative position to the inoperative position, the pres.- sure fluid flows from the pressure chamber in the consumer apparatus through the control valve along a tortuous path on which it is several times deflected.

Due to the repeated deflection of the flows of fluid, delays occur during the shifting of the control valve between the two control positions in which fluid is supplied to, or discharged from the pressure chamber of the consumer apparatus.

Modern machines operate at very high frequencies of the strokes, which requires short shifting periods for the control valve, and shorter periods of time for filling and discharging the pressure chamber.

SUMMARY OF THE INVENTION It is one object of the invention to provide a control valve which requiresless time for shifting, and shorter filling and discharge periods than control valves of the of aconsumer apparatus, and a return and discharge opening. In accordance with the invention, valve piston means are provided which close the discharge opening of the straight passage while fluid is supplied into the passage and through the same to the pressure chamber of the consumer apparatus.

Due to the straight connection between the return and discharge opening and the connection with the expansible and contractable pressure chamber of the consumer apparatus, such as a hydraulic pressure, very short filling and emptying periods are obtained, which is due to the fact that the direction of flow of the pressure fluid need not be changed, also due to the fact that straight passage and closing the discharge opening.

The valve pistons are moved by pressure fluid in the supply conduit means and in the working cylinders to the second control position so that the discharge opening is closed, and pressure fluid flows through the channel means into the straight passage and out of the same into the pressure chamber of the consumer apparatus for expanding the same. l I

In the preferred embodiment of the invention, two oppositelyv arranged valve pistons have confronting inner frustoconical end portions cooperating with corresponding frustoconical valve seats. Each of the valve seats has a slot, and the slots are respectively closed by the two valve pistons in the second control position.

, It is preferred to provide a channel in the valve pistons through which pressure fluid is guided into the straight passage. A spring between the valve pistons urges the same apart to the first control position. It is advantageous to provide check valves in the channels of the valve pistons, so that the valve pistons close the discharge opening of the straight passage, before the check valves open and the pressure fluid can flow through the straight passage into the pressure chamber of the consumer apparatus.

When a very large volume is required, it is advantageous to provide a valve for directly connecting the fluid inlet conduit with'the straight passage.

In a preferred embodiment of the invention, each valve piston has its outer peripheral surface, at least one channel recess which is directly connected with the inlet conduit for the pressure fluid, and through which the pressure fluid can flow into the straight passage when the valve pistons are placed in the second control position closing-the discharge opening. In such an arrangement, even a very great volume of pressure chamber, does not require an additional direct connection by a valve between the fluid inlet conduit and the the pressure fluid is not deflected during flow through a supplying the pressure fluid into the working cylinders.

Channel means connect'the supplyconduit means with the passage portions of the passage. Valve pistons are located in the working cylinders for movement toward and away from the straight passage between a first constraight passage. v It is advantageous to make the diameters of the piston parts outwardly of the channel recesses greater than the diameter of the piston parts located inward of the channel recesses, so that the pistons are urged outwardly to the first control position opening the discharge opening.

A further feature of the invention is to provide a double piston in a pressure cylinder forming balancing chambers at the ends of the pressure cylinder which are connected by first ducts with supply conduits for the fluid, and by second ducts with the straight passage. In such an arrangement, the double piston is operated to move to one of its end positions and to actuate a stop motion switch for the consumer apparatus, if one of the control valves for controlling the flow of pressure fluid to the channels of the valve pistons does notproperly function, or if one of the valve pistons is blocked.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic sectional view illustrating a first embodiment of the invention in a first control position;

FIG. 2 is a fragmentary schematic sectional view taken on line Il-II in FIG. 1;

FIG. 3 is a schematic sectional view illustrating the embodiment of FIG. 1 in a second control position;

FIG. 4 is a fragmentary schematic sectional view taken on line IV-IV in FIG. 3;

FIG. 5 is a schematic section illustrating the embodiment of FIG. 1 in undesired condition caused by a malfunction;

FIG. 6 is a fragmentary cross section taken on line VI-VI in FIG. 5;

FIG. 7 is a schematic section illustrating a modification of the embodiment of FIG. 6 in a first control positron;

FIG. 8 is a schematic sectional view of he embodiment of FIG. 7 in a second control position;

FIG. 9 is a schematic sectional view illustrating another embodiment of the invention in a first control position;

FIG. 10 is a fragmentary cross sectional view taken on line X-X inFIG. 9;

FIG. 11 is a schematic sectional view of the embodiment of- FIG. 9 is a second control position; and

FIG. 12 is a fragmentary sectional view taken on line XII-XII in FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 to 4, a control valve 10 has a housing 12 in which two

valve pistons

14 and 16 are movably mounted in working

cylinders

15 and 17. The two

pistons

14 and 16 are coaxial, and movable toward and away from each other. The confronting inner end portions 18 and 20 of the two

pistons

14 and 16 are frustoconical, and cooperate with corresponding

frustoconical valve seats

22 and 24. The working cylinders l5 and 17 are connected at the inner ends thereof by a passage portion.25.

Valve pistons

14 and 16 are sealed in working

cylinders

15 and 17 by sealing rings 14a and 160. Each of the

pistons

14 and 16 has a cen-. tral axially extending channel or bore 26,28, respectively see FIG. 2, to which pressure fluid is supplied from

supply channels

72 and 74 communicating through

supply conduits

64 and 66 with an inlet conduit 62. A compression spring 30 is mounted in the aligned bores 26 and 28, and has outer ends abuting

shoulders

32 and 34 provided in bores 26 and 28. Spring 30 urges the two

valve pistons

14 and 16 apart. A

check valve

36 and 38, respectively, is provided in each bore 26 and 28.

As shown in FIGS. 2 and 4, a passage 44 has an opening 40 at one end which is connected with the expanding and contracting pressure chamber of a hydraulic press, not shown, and has a discharge opening 42 at the other end thereof so that a pressure fluid discharged by the contracting pressure chamber of the hydraulic press can flow through passage 44 and out of discharge opening 42'without pressure loss. In accordance with the invention, the passage 44 between the

openings

40 and 42 is straight so that fluid flowing into opening 40,

through passage 44 and out of discharge opening 42, is not deflected, and consequently encounters very little flow resistance.

The straight passage .44 has two

portions

45 and 47,

of which the portion 45 is connected with the pressure chamber of the hydraulic press, and portion 47 is connected with the return conduit. The portion 45 is connected by a single opening 46 with the central space 49 from which a pressure fluid supplied through channels 26 and 28 can flow through portion 45 of passage 44 to the consumer apparatus, or through the discharge opening in portion 47 to the return conduit. The portion 47 of the straight passage 40 communicates with the central space 49 through two

discharge slots

48 and 50 which are separated by a partition body 52, as best seen in FIGS. 2 and 4.

The

dischargeslots

48 and 50 have openings in the

valveseats

22 and 24 of the

valves

76 and 78, each of which includes one of the

valve pistons

14 and 16, and the

respective valve seats

22 and 24. The

working chambers

77 and 79 of

valves

76 and 78 are connected by

supply conduits

72 and 74 with

control valves

54 and 56 which have

valve seats

58,68, and 60,70, respectively. The valve seats 58 and 60 of the, two

control valves

54 and 56 are connected by

supply conduits

64 and 66 with the inlet conduit 62 to which pressure fluid is supplied in the direction of the arrow P. A pump, not shown, may be connected with the inlet conduit 62. The

valve pistons

68 and 70 of the

control valves

54 and 56 are, for example, electromagnetically operated. Control valve 56 controls valve 78, and control valve 54 controls valve 76. The control valve device 10 is provided with a stop motion arrangement for stopping the consumer apparatus, such as a hydraulic press, when a malfunction takes place. A pressure balancing device is provided for this purpose, and includes a double piston 82 movable in a pressure cylinder 83 in housing 12. The end faces 84 and 86 of the double piston 82 form balancing chambers and 87 which-are connected by

ducts

92 and 94 with the

supply conduits

72 and 74 which connect the

control valves

56,54 with the working

chambers

77 and 79, and also connected by

ducts

96 and 98 with the spaces 97 and99 in front of valve pistons 14' and 16. As shown in FIGS. 1 and 3,

ducts

96 and 98 open at the valve seats 22 and 24.

Check

valves

100 and 102 are provided in the

ducts

92 and 94, together with

throttles

103 and 105. Double piston 82 has slanted actuating faces 104 and 106 which control the actuator ofa stop motion switch 110.

The control valve device 10 shown in FIGS. 1 to 4 operates as follows:

In the position of FIG. 1, the two

control valves

54 and 56 are closed, and pressure fluid cannot flow through

conduits

62, 64, 66 and

valve seats

58 and 60. Neither

valves

76 and 78, nor the stop motion device 80 are subjected to fluid pressure. Double piston 82 is in a central position due to the action of

springs

88 and 90. Stop motion switch 110 is open.

Valve pistons

14 and 16 are in the retracted outer positions and the pressure chamber of the consumer apparatus, not shown, is

connected with the opening 40 and through the straight When the two

control valves

54 and 56 are simultaneously actuated by electromagnetic means, they assume the position shown in FIG. 3, and the two

relief openings

68 and 70 are'closed, while the

valve seat openings

58 and 60 are opened. The pressure fluid and 38 in channels 26 and 28 of pistons- 16 and 14 permit the building up of pressure in the working

chambers

77 and 79 before opening the channels 26 and 28 forthe flow of pressure fluid from the working chambers into the straight passage 44. The

pistons

14 and 16 move towards each other until they abut on the valve seats 22 and 24, and close in this controlposition, the

discharge slots

48 and 50 which communicate with the discharge opening 42 of the return conduit. The

check valves

36 and 38 open so that the pressure fluid flows into the central space 49 and out of opening 46 into the end portion 45 of the straight passage 44 which is connected with the pressure chamber of the consumer apparatus.

The end faces 84 and 86 of the safety device 80 are subjected to equal pressure of the pressure fluid which flows through

ducts

92 and 94.

Ducts

96 and 98 which open in the valves seats are closed by the

valvev pistons

14 and 16 in the inner control position. Consequently,

the double piston 82 remains in the central position. so that stop motion switch 110 is not actuated.

FIGS. 5 and 6 illustrate a malfunction of. the device. It is assumed that upon shifting of

control valves

54 and 56 by electromagnetic means, only the controlvalve 54 opens, as control valve 56, perhaps due to failure of the electromagnetic means, has remained in the inoperative position closing opening 60.

Piston 14 is subjected to pressure and moves towards its valve seat, while piston 16 remains in the outer inoperative position. Discharge slot 50 is closed by piston 14, while discharge slot 48'remains open. The pressure fluid flows through control valve 54 and opening 58 into the working chamber 77 and through the respective check valve 38 and the corresponding channel 26 and the open discharge slot 48 directly tothe return conduit. The ratio between the flow across sections of the

control valves

54 and 56 and the channel 26 is about 1:10 so that in the interior of the valve, only a small pressure remains which is below the pressure required by the pressure chamber of the .consumer apparatus, such as a coupling or a brake of a press. Consequently, no pressure fluid is supplied to the consumer apparatus.

Due to the one-sided pressure in the balancing chamber 85, whichis not opposed by an equivalent pressure in the balancing chamber '87 due to the fact that the control valve 56 has not operated, double piston 82 moves to the leftas viewed in FIG. 5 so that the slanted face 106 operates the actuator pin of the stop motion switch 110 which disconnects to a relay, not shown, the main switchof the press which is thus stopped.

The position of the control valve device shown in FIGS. 5 and 6also results in the event that both control valves .54 and 56 are correctly operated, but valve piston16 is blocked in this outer position. The pressure fluid flows through the channels in the

valve pistons

14 and 16, and then flows through the open discharge slot 48 into thexreturn conduit. The pressure fluid further flowsthrough duct 92 and duct 94 towards the balancing

chambers

87 and 85. While duct 96 is closed by valve piston 14- so that pressure can develop in the balancing chamber 85, 1duct98 is open since valve piston 16 has not moved-forward to the inner control position. The fluid flowing through duct 94 con} sequently flows through duct 98 into the space97' in front of valve piston'16, and out of discharge slot 48. No pressure can develop in balancing chamber 87 so that the double piston 82 moves to the left and operates the stop motion switch 10.

The same condition of the device is obtained when the

control valves

54 and 56 are shifted out of the position shown in FIG. 3 to the position of FIG. 1, while valve piston. 14 is blocked in the inner control position shown in FIG. 5. Valve piston 16 is moved to the outer control position by the action of spring 30, so that discharge slot 48 leading to the return conduit, and also the opening of the duct 98 which is connected with balancing chamber 87 is uncovered. The pressure chamber of the consumer apparatus is relieved since the straight passage 44 to the discharge opening 42 is opened. In the same manner, the balancing chamber 87 is relievedsince the pressure fluid flows away through duct 98. It is not possible for the pressure fluid to flow out of the balancing chamber 85, since the check valve 100 prevents relief through the

control valves

54,56, andduct 96 is closed by the blocked valve piston 14. The endface 84 of the double piston 82 is subjected to fluid pressure, while the end face 86 is relieved. Due to the pressure differential, the double piston 82 moves out 'of the'central position as shown in FIG. 3 to the left, so that stop motion switch is operated.

Preferably, throttles 103 and 105 are provided .in

ducts

92 and 94 in order to equalize small motion and shifting tolerances of the valves, and also for obtaining a uniform pressure built up in the safety device 80. For the same reason, double piston 82 may be provided with a throttle connecting the two end faces.

A modified embodiment of the invention illustrated in FIGS. 7 and 8 corresponds to the embodiments of FIGS. 1 to 6, but has a different channel arrangement for connecting the inlet conduit 82 with the straight passage 44.

For large volumes, the flow cross section of the

control valves

54, 56 is insufficient for a large pressure chamberof the brake or clutch of the consumer apparatus, and therefore a large valve means with a larger cross section is provided in housing 12, and is operated .by an actuating piston 124. Valve 120 is connected by a channel 122 with the inlet conduit 62. The auxiliary piston 124 is connected by a piston rod 125 with valve 120, and is controlled by control valve 54 through a channel 126. In the open position of valve .120 shown in FIG. 8, pressure fluid from inlet conduit 62 flows through valve seat 128 and a connecting chan- .nel 130 directly into the portion 45 of the straight passage 44 which is connected with the consumer apparatus, as explained with reference to FIG. 2. Due to the direct connection between the inlet-conduit 62 and the straight passage 44, it is not necessary to supply fluid through

supply conduits

72 and 74 and channels 26,28 in

pistons

14 and 16, as described with reference to FIGS. 1 and 2.Instead of the channels 26 and 28, corresponding blind bores are provided in

pistons

14 and 16 in which spring- 30 is located for urging the pistons away from each other.

In the event that the valve 120 malfunctions and, for example, remains in the closed position as shown in FIG. 7, no fluid is supplied to the consumer apparatus. In the event that the valve 120 remains in its open position after the

control valves

54 and 56 have been shifted, perhaps due to jamming of piston 124, the supplied pressure fluid flows through the

discharge slots

48 and 50 which are opened by the retracted

pistons

14 and 16. Consequently, a single valve 120 is sufficient.

In the embodiment illustrated in FIGS. 9 to 12, each of the two valve pistons 14'.and 16 has four

channel recesses

140 and 142, respectively, which extend parallel to the axis of symmetry of the respective piston and over a part of its axial length. The channel recesses 140 and 142, respectively, are spaced 90 in circumferential direction, and the bottom of the channel recesses 140,142 is preferably part-circular so that the channel recesses 140,142 are substantially segment shaped, as shown in the drawing.

The channel recesses form part of the channel means by which the inlet conduit 62 is connected with the straight passage 44 when the valve piston 14' and 16 are in the inner control position shown in FIG. 12. The channel recesses, and associated channels, replace the channel bores 26 and 28 of the embodiment of FIGS. 1 to 4 In the position of the control valve device shown in FIGS. 9 and 10, the

control valves

54 and 56 are closed. The channel recesses 140 and 142 register with

openings

160 and 162 and annular channels 161,163 in housing 12, and are further connected by supply conduits64 and 66 with an inlet conduit 62 through which the pressure fluid is supplied. Sealing means 156 and 158 in housing 12 prevent in the position of FIG. 9, the flow of pressure fluid from channel recesses 140,142 into the straight passage 44. Sealing means 156 and 158 cooperate with

portions

148 and 150 of the valve pistons 14' and 16'. Sealing means 152,154 seal the channel recesses 140,142 from the

separate conduits

72 and 74 which are supplied with fluid when the

control valves

54 and 56 are operated. Sealing rings 152,154 are mounted in

annular portions

144 and 146 of the valve pistons 14' and 16'.

When the

control valves

54 and 56 are moved to the position of FIG. 11, pressure fluid flows through

valve seats

60 and 58 into the

supply conduits

72 and 74 and exerts pressure on the outer end faces of valve pistons 14' and 16' so that the valve pistons move to the inner control position closing the

discharge slots

48 and 50 which communicate with the discharge opening 42.

The channel recesses 140,142 are in this control position not any more sealed from the straight passage 44. The pressure fluid flows through inlet conduit 62,

supply conduit

64 and 66,

openings

160 and 162, and

annular channels

161 and 163 into the channel recess 140.142 and out of the same through annular gaps 164,166, see FIG. 12, so that the fluid enters the straight passage 44 and flows to the consumer ap'- paratus. Annularchannels 168,170, see FIG. 12, are provided in housing 12 through which the pressure fluid flowing out of annular gaps 164 and 166 is guided to the opening 40 communicating with consumer apparatus. Y

As is apparent from the drawing, the diameter of the piston portions 154,156 which are located outwardly of the channel recesses 140,142 is greater than the diameter of the portions 148,150 which are located inwardly of the channel recesses 140,142. In this manner, a pressure differential is obtained which urges the. valve pistons14' and 16' outof the control position shown in FIG. 9. The embodiments of FIGS. 9 to 12 is particularly advantageous since it. is suitable for very high volumes of the pressure chamber'of theconsumer apparatus without requiring valve 120 of the embodiment of FIGS. 7 and 8.

The spring by which the fluid is pressed out of the working chambers of valve pistons 14 and 16' in the embodiments of FIGS. 1 to 8, can be so designed that it permits a closing of the straight passage 40 by the valve pistons only at a predetermined pressure, for example more than 3 k/cm. Such an arrangement eliminates the necessity of providing a pressure operated switch responsive to the pressure of the fluid.

More than one safety device may be provided for operating other switches when a malfunction takes place. It is advantageous to make the valve pistons of a synthetic plastic material so that the mass is small, permitting a further reduction of the time periods for acceleration of the pistons so that the time required for shifting the control valve device is further reduced.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of control valve devices differing from the types described above.

While the invention has been illustrated and described as embodied in a control valve device including a straight passage for connecting the variable pressure chamber of a consumer apparatus with a discharge opening, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptions should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. Control valve for controlling the flow to and from a variable pressure chamber of a consumer apparatus, comprising housing means including a substantially straight passage means connected at one end with said pressure chamber, and having at the other end thereof a discharge opening, said housing means having working cylinder means laterally of said straight passage means, and supplyconduit means including an inlet conduit for supplying a pressure fluid into said working cylinder means; channel means connecting said supply conduit means with apassage portion of said passage means; and valve piston means located in said working cylinder means for movement toward and away from said straight passage means between a first control position retracted from said straight passage means so that fluid from said pressure chamber flows through said straight passage means and directly out of said discharge opening, and a second control position located in said straight passage means and closing said discharge opening, said valve piston means being moved by pressure fluid in said supply conduit means and in said working cylinder means to said second control position so that said discharge opening is closed, and pressure fluid flows through said channel means into said passage portion and out of said one end into said pressure chamber for expanding the same.

2. Control valve as claimed in claim 1,;wherein said working cylinder means includes two working cylinders located on opposite sides of said straight passage means; wherein said valve piston means include two valve pistons located in said working cylinders; wherein said supply conduit means includes two supply conduits respectively connecting said inlet conduit with said working cylinder; wherein said channel means includes two channels formed by said valve pistons, respectively, and communicating with said working cylinders, respectively; and wherein fluid pressure in said supply conduits and working cylinders-simultaneously urges said valve pistons to said second control position for together closing said discharge opening while pressure fluid flows through said channels and straight passage means into said pressure chamber.

3. Control valve as claimed in claim 2, wherein said working cylinders form frustoconical valve seats adjacent said straight passage means; and wherein said valve pistons have inner confronting frustoconical end portions abutting said frustoconical valve seats in said second control position. v

4.. Control valve as claimed in claim 3, wherein said straight passage means includes a partition body divide ing said discharge opening into two discharge slots; wherein said frustoconical end portions of said valve piston in said second control position abut said partition body and close said discharge slots.

5. Control valve as claimed in claim 4, wherein said work-ing cylinders are located outward of said valve pistons and receive the end portions of said valve pistons remote from said frustoconical end portions.

6. Control valve as claimed in claim 4, wherein said frustoconical end portions have central end faces spaced from each other in said second control position and located in said passage portion; and wherein said channels extend axially of said frustoconical end portions in said valve pistons and open on said end faces for connecting said supply conduits with said passage portion.

7. Control valve as claimed in claim 2 wherein said channel means include axially extending bores in said valve pistons having partly closed outer ends; and a pressure spring located in said bores between said partly closed ends, and urging said valve pistons apart to said first control position.

8. Control valve as claimed in claim 2, wherein said channels'extend between the outer and inner ends of said valve pistons, respectively; and comprising biassed check valves located in said channels, respectively, and adapted to close said channels so that said valve pistons are moved to said second controlposition by the pressure in said working cylinders whereupon the pressure increases in said working chambers and opens said check valves to permit flow through said channels into said passage means and out of 'said one end of the same.

9. Control valve as claimed in claim 2, comprising two control valves mounted in said housing means operable between an operative position opening said supply conduits, respectively, and an inoperative position closing the same so that the movements of said valve pistons are controlled by said control valves; and wherein the ratio between the effective flow cross sections of said supply conduits controlled by said control pistons and said channels in said valve pistons is about 1:10.

10. Control valve as claimed in claim 1, comprising a valve means located in said channel means and having a closed position, and an open position for connecting said inlet conduit directly with said straight passage means.

11. Control valve as claimed in claim 10, comprising control valve means mounted on said housing means operable between an operative position connecting said inlet conduit with said working cylinder means, and .an inoperative position disconnecting the same; and comprising actuating piston and cylinder means for operating said valve means under the control of said control valve means.

12. Control valve means as claimed in claim 1, wherein said working cylinder means include two working cylinders located on opposite sides of said straight passage means; wherein said valve piston means include two valve pistons located in said working cylinders, respectively; wherein said supply conduit means include two supply conduits connecting said inlet conduit with said working cylinders, respectively; and wherein said channel means include channel recesses in said valve pistons communicating with said inlet conduit and being closed in said first control position,and communicating also with said straight passage means in said second control position.

13. Control valve as claimed in claim 12, wherein said valvepistons comprise sealing rings engaging said working cylinders in said first control position for sealing said channel recesses against communication with said straight passage means.

14. Control valve as claimed in claim 12, wherein channel recesses include a plurality of channel recesses spaced circumferentially about each of said valve pistons.

15. Control valve as claimed in .claim 14, wherein said channel recesses extend in the respective valve piston parallel to the axis of symmetry of the same and over a part of the length of the same.

16. Control valve as claimed in claim 12, wherein each of said channel recesses has a part-circular bottorn and is segment shaped.

17. Control valve as claimed in claim 12, wherein each valve piston has a greater diameter at the outer end portion remote from said straight passage means than at the inner end portion thereof; and wherein said channel recesses are located between said inner and outerend portions.

18. Control valve as claimed in claim 1, wherein said working cylinder means include two working cylinders located on opposite sides of said straight passage means; wherein said valve piston means include two valve pistons located in said working cylinders, respectively; wherein said supply conduit means include two supply conduits connecting said inlet conduit with said working cylinders, respectively; wherein said housing means forms a pressure cylinder having ends; comprising a double piston in said pressure cylinder forming balancing chambers at said ends of said pressure cylinder and being movable between a central inoperative position, and two end positions; a stop motion switch actuated by said double piston in said end positions; wherein said housing means has first ducts connecting said supply conduits with said balancing chambers, respectively, and second ducts connected with said balancing chambers, respectively, and communicating with said straight passage means in said first control positions of said valve pistons, and being closed, respectively, by the respective valve piston in said second control position of the same whereby malfunctions of any valve piston causes movement of said double piston to one end position and actuation of said stop motion switch.

19. Control valve as claimed in claim 18, wherein 12 said valve pistons have confronting inner ends; wherein said housing means include valve seats for said inner ends engaged by the same in said second control position; and wherein said second ducts open in said valve seats, respectively, and are closed by the respective valve piston in said second control position of the same.

20. Control valve as claimed in claim 18, comprising check valves in said first ducts for blocking flow from said balancing chambers into said supply conduits, respectively.

21. Control valve as claimed in claim 18, comprising throttle means in said first ducts, respectively.

22. Control valve as claimed in claim 1 wherein said housing means has a top portion in which said one end of said straight passage means forms an opening communicating with said variable pressure chamber, and a bottom portion in which the other end of said straight piston means are controlled by said control valve

Claims

1. Control valve for controlling the flow to and from a variable pressure chamber of a consumer apparatus, comprising housing means including a substantially straight passage means connected at one end with said pressure chamber, and having at the other end thereof a discharge opening, said housing means having working cylinder means laterally of said straight passage means, and supply conduit means including an inlet conduit for supplying a pressure fluid into said working cylinder means; channel means connecting said supply conduit means with a passage portion of said passage means; and valve piston means located in said working cylinder means for movement toward and away from said straight passage means between a first control position retracted from said straight passage means so that fluid from said pressure chamber flows through said straight passage means and directly out of said discharge opening, and a second control position located in said straight passage means and closing said discharge opening, said valve piston means being moved by pressure fluid in said supply conduit means and in said working cylinder means to said second control position so that said discharge opening is closed, and pressure fluid flows through said channel means into said passage portion and out of said one end into said pressure chamber for expanding the same.

2. Control valve as claimed in claim 1, wherein said working cylinder means includes two working cylinders located on opposite sides of said straight passage means; wherein said valve piston means include two valve pistons located in said working cylinders; wherein said supply conduit means includes two supply conduits respectively connecting said inlet conduit with said working cylinder; wherein said channel means includes two channels formed by said valve pistons, respectively, and communicating with said working cylinders, respectively; and wherein fluid pressure in said supply conduits and working cylinders simultaneously urges said valve pistons to said second control position for together closing said discharge opening while pressure fluid flows through said channels and straight passage means into said pressure chamber.

3. Control valve as claimed in claim 2, wherein said working cylinders form frustoconical valve seats adjacent said straight passage means; and wherein said valve pistons have inner confronting frustoconical end portions abutting said frustoconical valve seats in said second control position.

4. Control valve as claimed in claim 3, wherein said straight passage means includes a partition body dividing said discharge opening into two discharge slots; wherein said frustoconical end portions of said valve piston in said second control position abut said partition body and close said discharge slots.

5. Control valve as claimed in claim 4, wherein said working cylinders are located outward of said valve pistons and receive the end portions of said valve pistons remote from said frustoconical end portions.

8. Control valve as claimed in claim 2, wherein said channels extend between the outer and inner ends of said valve pistons, respectively; and comprising biassed check valves located in said channels, respectively, and adapted to close said channels so that said valve pistons are moved to said second control position by the pressure in said working cylinders whereupon the pressure increases in said working chambers and opens said check valves to permit flow through said channels into said passage means and out of said one end of the same.

11. Control valve as claimed in claim 10, comprising control valve means mounted on said housing means operable between an operative position connecting said inlet conduit with said working cylinder means, and an inoperative position disconnecting the same; and comprising actuating piston and cylinder means for operating said valve means under the control of said control valve means.

12. Control valve means as claimed in claim 1, wherein said working cylinder means include two working cylinders located on opposite sides of said straight passage means; wherein said valve piston means include two valve pistons located in said working cylinders, respectively; wherein said supply conduit means include two supply conduits connecting said inlet conduit with said working cylinders, respectively; and wherein said channel means include channel recesses in said valve pistons communicating with said inlet conduit and being closed in said first control position, and communicating also with said straight passage means in said second control position.

13. Control valve as claimed in claim 12, wherein said valve pistons comprise sealing rings engaging said working cylinders in said first control position for sealing said channel recesses against communication with said straight passage means.

15. Control valve as claimed in claim 14, wherein said channel recesses extend in the respective valve piston parallel to the axis of symmetry of the same and over a part of the length of the same.

16. Control valve as claimed in claim 12, wherein each of said channel recesses has a part-circular bottom and is segment shaped.

17. Control valve as claimed in claim 12, wherein each valve piston has a greater diameter at the outer end portion remote from said straight passage means than at the inner end portion thereof; and wherein said channel recesses are located between said inner and outer end portions.

19. Control valve as claimed in claim 18, wherein said valve pistons have confronting inner ends; wherein said housing means include valve seats for said inner ends engageD by the same in said second control position; and wherein said second ducts open in said valve seats, respectively, and are closed by the respective valve piston in said second control position of the same.

22. Control valve as claimed in claim 1 wherein said housing means has a top portion in which said one end of said straight passage means forms an opening communicating with said variable pressure chamber, and a bottom portion in which the other end of said straight passage means forms said discharge opening; wherein said valve piston means are movable in a direction transverse to said straight passage means; and wherein said supply conduit means are located in a plane transverse to said straight passage means; and further comprising control valve means mounted in said housing means operable for opening and closing said supply conduit means so that the movements of said valve piston means are controlled by said control valve means.