US3189050A - Pressure fluid operable control valve - Google Patents

Description

June 31 5, .1965 s. HECKMA'NN PRESSURE FLUID OIERABLE CONTROL VALVE Filed June 19, 1 961 INVENTOR. GU/VTEA HECKMflNN .is additionally of diiferent direction.

3,189,050 PRLSiURE FLUlD GKERABLE CGNTRGL VALVE Gunter Hechmann, Schult Enhrinlr 52, Sproclrhovel, Westphalia, Germany Filed June 19, 1961, Ser. No. 117,936

(Ilaims priority, application Germany, June 21, 1960,

H 39,723 6 Claims. (Cl. 137-625.63)

The present invention relates to a control valve for any type of fluid means, especially for compressed air, with single impulse relief actuation, in which the respective impulse of any desired duration will adjust the main valve spool always in the respective opposite reversing position.

Relief impulses are initiated for instance by a simple outlet valve operable manually, mechanically, electromagnetically, pneumatically, hydraulically, or in any other possible manner. Such a relief valve may be mounted on a control valve itself or remote therefrom. The valve spool may be provided with two, three or four pistons which according to the threeor four-way principle may control the flow of fluid to a machine element on one or both sides, for instance a fluid pressure cylinder or a fluid pressure motor movable in one direction or in opposite directions.

Attempts have been made to solve this problem by preceding the control valve by a flutter valve (Flatterventil) in such a way that the relief impulse brings about a discharge of the pressure fluid to one or another flutter valve branch and thereby moves the valve to the outlet seat whereby in the other branch of the flutter valve the fluid medium is controlled with the result that the valve spool is reversed. This type of control works, however, only at a predetermined pressure inasmuch as it is dependent to a high extent on the respective cross section. In other words, this type of control will frequently respond already to small accumulations of soil, to leakages or to displacements of lubricants. This known control is, therefore, suitable only for control work where the emphasis is more on saving control conduits rather than on-a safe operation and on avoiding reverse control operations.

This known control functions only at short strokes of the working cylinder to be controlled because the pressure fluid to be distributed through the flutter valve is controlled by the control valve in the feeding line to the machine element. This known control, therefore, causes already at passages which are deliberately held small a new non-controllable relief impulse upon the flutter valve. This is particularly the case when the relief impulse Moreover, this control is suitable only for compressed air.

Other control valves which by means of single relief impulses move the valve spool in the respective opposite positions have not been known heretofore.

It is, therefore, an object of the present invention to provide a control valve which will overcome the above mentioned drawbacks.

It is another object of this invention to provide a control valve which in an absolutely safe manner will assure a single impulse relief control.

These and other objects and advantages of the inven tion will appear more clearly from the following specification in connection with the accompanying drawing in which:

FIG. 1 illustrates a longitudinal section through a first United States Patent 0 embodiment of a control valve according to the present invention.

FIG. 2 is a longitudinal section through a modified control valve according to the present invention.

The objects of the present invention have been realized "ice primarily in that the main control valvehas associated therewith an auxiliary valve spool which is adapted alternately to effect communication between the relief conduits on the left-hand and right-hand side of the main valve spool with a relief means, for instance a discharge valve adapted to be actuated by any desired means. The said auxiliary valve spool is controlled and held in its reversing positions by a pressure fluid medium alternately reversed by the main valve spool and passed into the pressure fluid conduits which are branching off from the working path of the main valve spool. The respective reversal of the auxiliary valve spool may in spite of the pressure fluid prevailing at the respective point be effected only when the relief conduit has again been closed. This is brought about by permitting the pressure fluid medium which is intended to adjust the auxiliary valve spool for the next following relief operation and the flow of which to the auxiliary valve spool is controlled by the main valve spool, to flow off through a check valve and through the relief impulse conduit as long as the relief impulse will last. Only after the relief impulse has ended, the pressure intended for reversing the auxiliary valve spool or pre-control member can build up. trol, any reversal of the main control valve spool will be made impossible. It is for this reason that already the first tests have resulted in more than 50,000 fault free sequential controls.

Control valves according to the present invention are particularly suitable for use in connection with electromagnetic valves. This is due to the fact that the control valve according to the present invention will for purposes of initiating impulses operate with the smallest known electromagnetic valves at cross sections of a diameter of a few millimeters up to the greatest practically occurring diameters. An electromagnet with a 15% duration of lead application in form of a simple alternating current or direct current magnet will sufiice for actuating the valve according to the present invention so that when employing alternating current, the heretofore customary rectifier will become superfluous because permanent magnet switch operations will not be requir ed any longer. The possible control frequency has furthermore, when employing compressed air, proved enormously high so that the relief impulses may be very short. However, the fact that the auxiliary valve spool will be reversed only after the relief impulse for the next following impulse has been completed, will make possible an impulse duration which is not limited as to time as this is possible for instance with impulse emitters, as

for example a nut on a threaded spindle which nut is to be stopped in the very position in which it releases the impulse. Such an arrangement prevails with mechanically actuated relief valves used in connection with a rope winding device.

Referring now to the drawing in detail and FIG. 1 thereof in particular, this figure shows a practical embodiment of the present invention which has proved highly successful. The control valve illustrated in FIG. 1 comprises a housing 14 having reciprocably mounted therein a four-piston valve spool 17. The pressure fluid enters at 26 into the piston annular chamber 18 and is passed through bores 24, the central piston bore 23 and bores 25 into the annular chamber 2%}. In addition thereto, the pressure fluid passes through relatively narrow bores 15a, 16a in the valve spool end faces 15, 16 to both sides of the valve spool into the chambers 21 and 22. In the particular position shown in the drawing, the valve spool 17 establishes communication between the pressure fluid inlet 26 and the passage 27 leading to the device to be controlled and the outlet 28. The outlet connection 1 in the pre-control housing 3 or the housing for the. auxiliary Patented June 15, 1965 In view of this automatic sequence of con- .15 valve spool and the outlet connections 30 and 31 in the main housing 14 have connected thereto conduits 1a, 33 and 34 which have arranged therein for instance simple discharge valves A, B and C. Normally, the valves A, B and C are closed.

Small conduit 11 leads from the annular chamber 18 of the valve spool to the right hand end of the bore in housing 3, while small conduit leads from the annular chamber 19 of the valve spool to the left end of the bore in housing 3.

The operation of the valve of FIG. 1 according to the present invention is as follows:

When the shutoff valve A mounted in the impulse conduit 1a is opened-said valve A acting in this instance as impulse producing valve-pressure fluid will pass from the chamber 22 at the right-hand side of housing 22 (with regard to FIG. 1) .through the relief passage 13 into the annular chamber 8 of the pre-control valve spool 2 and from there through connection and valve A into the conduit 1a. This will cause a sudden pressure drop in chamber 22 because the quantity of pressure fluid which at this time can pass through the small bore 16a of the valve spool 17 into chamber 22 is only very small and, therefore, cannot make up the pressure lost from chamber 22 on account of the just described passage of fluid from the chamber 22 into conduit 1a. This situation creates a substantial pressure difference between chamber 21 and chamber 22, the pressure in chamber 21 being maintained by the oncoming pressure fluid passing through the bore a of the valve spool 17. Valve spool 17 is thus caused to move toward the right in the direction toward the lid 14a. While previously the small branch conduit 11 was conveying pressure fluid and thereby held the pre-control valve spool 2 in its left-hand end position, whereas in this instance the branch conduit 10 communicated with the exhaust chamber 19, the two small branch conduits 10 and 11 will have their functions reversed when the main valve spool 17 has moved toward the right. The annular chamber will then convey pressure fluid to the machine element to be actuated whereas the annular chamber 19 will then establish communication between conduit 27 and exhaust 28. Thus, the branch conduit 10 Will convey pressure fluid while the branch conduit 11 communicates with the exhaust 28. The pressure fluid which passes through the relatively narrow conduit 10 will through bore Sin the pre-control valve spool 2 move the check valve ball 4' toward the right with regard to FIG. 1 to such an extent that the pressure fluid entering through conduit 10 will pass through small bores 7 of valve spool 2 and its annular chamber 8 into the impulse conduit 1a. This condition will be absolutely stable and will remain table as long as the shut-off valve A is in its open position.

If valve A and thereby conduit 1a is again closed, pressure will build up in theannular chamber 8 of the precontrol valve spool. This pressure will act upon the check valve ball 4 and press the latter onto its right-hand seat 6. As a result thereof, the pressure acting upon the left-hand end face of the valve spool 2 will move the latter into its right-hand end position. The pressure prevail-- ing in conduit 10 and acting on the right-hand side of valve spool 2 will maintain this condition stable, iLe. will maintain valve spool 2 in its right-hand position because now also branch conduit 11 communicates with the exhaust and thus maintains the right-hand end face of valve spool 2 pressure-less. Consequently, the valve spool 2 maintains the relief passage 13 closed whereas the relief passage 12 will now communicate with annular chamber 8 of valve spool 2 and thereby will also communicate with the impulse passage 1a. The entire arrangement is now ready for the next relief impulse which when initiated will bring the main valve spool 17 and also the pre-control valve spool 2 back into the position shown in FIG. 1.

The main valve spool 17 will shortly before reaching its end position move over the relief passage 12 or 13 for cushioning purposes only. The housing 14 may with this relief impulse control additionally be provided with two further relief connections 30 and 31 for special successive or safety control steps. The said two relief connections 30 and 31 when communicating with corresponding conduits bring about that the main valve spool is either displaced, as would be the case for instance when a relief impulse is conveyed through connection 30, or that for a certain control condition the main valve spool 17 will move into the proper position pertaining to said certain control condition. This may be the case when the relief would be effected through the connection 31. For this possibility, there may by way of example be mentioned a remote controlled switch adjusting device as it is actuated for instance by a travelling train in mining operations. In such an instance, the additional relief connections 30 and 31 are important because they could then always be automatically actuated in a simple manner when the train passes from a branch track through the switch to the main track. In such an instance the switch will safely be adjusted in the correct manner or will not be adjusted at all if it is already in its proper position. The valves B and C in conduits 33 and 34 provide for the above-mentioned control possibilities and are thus auxiliary impulse control means remote from valve A.

The fundamental principle underlying the control valve of the present invention may, of course, be varied as shown for instance in FIG. 2. According to this last mentioned embodiment, the valve spool 2 is replaced by a piston which, however, may also be replaced by other means as for instance a diaphragm.

With reference to FIG. 2, a one-step piston 2a is reciprocably mounted in housing 3 and is freely movable between two intermediate walls provided with bores 5a and 6a. This piston when occupying the position shown in the drawing covers the relief conduit 12 whereas the relief conduit 13 communicates through its right-hand free cylinder chamber and bore 6a and the chamber 8a through a check valve 4a with the impulse connection 1a. The branch conduit 11 which in this position is under pressure, likewise leads into chamber 8a, whereas the left-hand piston end face communicates through bore 5a, chamber 7a and branch conduit 10 with the exhaust 28. Thus, also in this instance the pressure fluid maintains the piston 2a in its left-hand position, and this position is absolutely stable.

If now a relief impulse is brought about at the connection 1a, the relief conduit 13 is relieved in the manner described above and the main control valve spool 17 will in conformity with the description of the arrangement of FIG. 1 be moved into its right-hand reversing position. In this way, also the function of the branch conduits 10 and 11 is reversed while pressure fluid passes through passage 1t) and is conveyed to the impulse connection 1a through the intervention of the easily movable check valve 411. The branch conduit 1 1 communicates with the exhaust 28.

Thus, also with this arrangement the decisive position of the entire device is stable. Furthermore, also in this instzmce the piston 2a can move into its right-hand reversing position only after the impulse conduit connected to connection 1a has been closed because only then it will be possible to build up the necessary pressure for initiating tE next impulse. It will thus be evident that the embodiment of FIG. 2 as far as its function is concerned fully corresponds to that of FIG. 1. The embodiment of FIG. 2 has the further advantage that it is structurally simpler and that the relief passages or conduits or branch conduits will not have to cross each other.

The control valve according to the present invention is particularly suitable for all control operations, especially where the control valve is to be actuated remote from its effective location because in all these instances merely one relief conduit or one electric conduit is required. This is the case for instance with remote controlled large shutoff valves, switch control devices, door actuating means, pneumatically, hydraulically or electrically operated cart pulling devices in mines where the control is advantageously arranged not between the rails of a mine track but at the joint or on the oil container.

A further essential advantage of the control valve according to the present invention consists in that it will operate independently of the cross section and of the length of the conduits leading to the devices to be controlled.

It is, of course, to be understood that the present invention is, by no means, limited to the particular constructions shown in the drawings but also comprises any modifications within the scope of the appended claims. Thus,

the main valve spool may also be replaced by a two-step V or three-step piston or may be designed as flat or rotary valve member or may function as valve system in combination with the pre-oontrol arrangement according to the present invention.

What Iclaim is:

1. In a control valve, a main housing having a pressure fluid inlet and an outlet, a main control member having end faces and reciprocable insaid housing between first and second end position-s, the end faces of said main control member respectively confining with said housing a first and a second end chamber, throttle means establishing a throttled communication between said pressure fluid inlet and said first and second end chambers, said housing also being provided with two relief passage means respectively communicating with said first and second end chambers, an auxiliary housing having an impulse outlet for connection with an impulse relief conduit, an auxiliary control member reciprocable within said auxiliary housing and forming therewith a pair of auxiliary end chambers, said auxiliary contnol memberbeing moveab-l-e from .a first position into a second position and vice versa in said auxiliary housing for respectively establishing communication between one of said relief passage means .and said impulse outlet While interrupting communication between the other relief passage means and said impulse outlet, a

conduit leading from each said end chamber of said auxil iary housing, said main control member in one end position connecting one of said conduits to said fluid inlet and the other thereof to said outlet and in the other end position connecting said other conduit to said fluid inlet while connecting said one conduit to said outlet, channel means respectively connecting the chambers of said pair of auxiliary end chambers with sa-idimpulse conduit, check valve means preventing direct communication between the chambers of said pair of auxiliary end chambers, and a valve controlling said impulse relief conduit.

2. In a control valve, a main housing having a pressure fluid inlet and an exhaust and also having a first port and a second port, a main valve spool having end faces and reciprocable in said housing between first and second positions, said main valve spool including a plurality' of control chamber means operable in one end position of said main valve spool to establish communication between said first port and said pressure fluid inlet while simultaneously establishing communication between said second port and said exhaust, said control chamber means also being operable in response to said main valve spool occupying its other end position to' establish communication between said second port and said pressure fluid inlet while simultaneously establishing communication between said first port and said exhaust, the end faces of said main valve spool respectively confining with said housing a first and a-second end chamber, throttle means establishing a throttled communication between said pressure fluid inlet and said first and second end chambers, said housing also being provided with two relief passage means respectively communicating with said first and second end chambers, an auxiliary housing having an impulse outlet for communication with an impulse relief conduit, an auxiliary control member having two oppositely located effective surfaces and being movable within said auxiliary housing from a first position into a second position and vice versa for respectively establishing communication between one or the other of said relief passage means with'said impulse outlet, first and second additional conduit means respectively connecting one of said effective surfaces of said auxiliary control member with one of said control chamber means and the other effective surface with another of said control chamber means in one end position of said main valve spool and reversing said connections in the other end position of said main valve spool, passage means leading from said effective surfaces to said impulse outlet, check valve means preventing fluid flow from said impulse outlet to said eifective surfaces while permitting fluid flow from said effective surfaces to said impulse outlet, and a valve operable for controlling said impulse conduit.

3. A control valve according to claim 1, in which said auxiliary control member is a one-step piston.

4. In a control valve, a main housing having a pressure fluid inlet and an outlet, a main valve spool having end faces and reciprocable in'said housing between first and second end positions, the end faces of said main valve spool respectively confining with said housing a T first and a second end chamber, throttle means establishing a throttled communication between said pressure fluid inlet and said first and second end chambers, said housing also being provided with two relief passage mean-s respectively communicating with said first and second end chambers, an auxiliary housing having an impulse outlet for connection with an impulse relief conduit, said auxiliary housing including a bore and also including first and second fluid conveying means at opposite ends of said bore, conduit means leading from said fluid conveying means and alternately connected to said fluid inlet and said outlet in response to movement of said main valve spool from one end position thereof to the other, said auxiliary housing furthermore including check valve means permitting fluid flow from said fluid conveying means to said outlet while preventing fluidflow in the opposite direction, piston means reciprocable within said bore from a first position into a second position and vice versa in response to fluid pressure in respective ones of said fluid conveying means for respectively establishing and interrupting communication between said relief passage means and said fluid conveying means, and a valve in said impulse relief conduit operable for selectively opening and closing said conduit.

5. A valve according to claim 1, which includes auxiliary impulse control means arranged remote from said impulse outlet for controlling said main control member.

6. A control valve according to claim 1, in which each said relief passage means leads into the pertaining said end chambers at a point therein such that the respective relief passage means will be covered by the respective adjacent end portion of said main control member in its respective adjacent end position whereby a cushion chamber remains in said end chamber in the respective adjacent end position of said main control member while movement of the main control member toward its other end position will uncover the said covered relief passage means.

References Cited by the Examiner UNITED STATES PATENTS 2,709,421 5/55 Avery 91-51 XR 2,867,191 1/59 Herrmann 12117 2,912,008 11/59 Blackburn 137--625.62 XR 2,939,430 6/60 Westbury 137--625.62 XR 3,012,575 12/61 Woody et a1. 137-62562 3,113,590 12/63 Olson 137--625.6

FOREIGN PATENTS 80,214 12/55 Holland. 146,983 12/54 Sweden.

MARTIN P. SCHWADRON, Acting Primary Examiner.

KARL I ALBRECHT, M. CARY NELSON, Examiners.

Claims (1)

1. IN A CONTROL VALVE, A MAIN HOUSING HAVING A PRESSURE FLUID INLET AND AND OUTLET, A MAIN CONTROL MEMBER HAVING END FACES AND RECIPROCABLE IN SAID HOUSING BETWEEN FIRST AND SECOND END POSITIONS, THE END FACES OF SAID MAIN CONTROL MEMBER RESPECTIVELY CONFINING WITH SAID HOUSING A FIRST AND SECOND END CHAMBER, THROTTLE MEANS ESTABLISHING A THROTTLED COMMUNICATION BETWEEN SAID PRESSURE FLUID INLET AND SAID FIRST AND SECOND END CHAMBERS, SAID HOUSING ALSO BEING PROVIDED WITH SAID RELIEF PASSAGE MEANS RESPECTIVELY COMMUNICATING WITH SAID FIRST AND SECOND END CHAMBERS, AN AUXILIARY HOUSING HAVING AN IMPULSE OUTLET FOR CONNECTION WITH AN IMPULSE RELIEF CONDUIT, AN AUXILIARY CONTROL MEMBER RECIPROCABLE WITHIN SAID AUXILIARY HOUSING AND FORMING THEREWITH A PAIR OF AUXILIARY END CHAMBERS, SAID AUXILIARY CONTROL MEMBER BEING MOVABLE FROM A FIRST POSITION INTO A SECOND POSITION AND VICE VERSA IN SAID

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