GB1591953A

GB1591953A - Multiway valves

Info

Publication number: GB1591953A
Application number: GB53418/77A
Authority: GB
Original assignee: Festo Maschinenfabrik Gottlieb Stoll Firma
Current assignee: Festo Maschinenfabrik Gottlieb Stoll Firma
Priority date: 1976-12-23
Filing date: 1977-12-22
Publication date: 1981-07-01
Also published as: DE2658515C2; ES465329A1; FR2375519A2; BR7708586A; FR2375519B2; IN149926B; JPS5380022A; DE2658515A1; SE432655B; IT1089209B; CH606879A5; SE7714638L; JPS6078173A

Description

(54) IMPROVEMENTS IN AND RELATING TO MULTIWAY VALVES (71) We, FESTO - MASCHINENFABRIK GOTTLIEB STOLL, a Company organised under the laws of the Federal Republic of Germany of Ulmer Strasse 48, 7300 Esslingen N, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it As to be performed, to be particularly described in and by the following statement: This invention relates to a multiway valve and is particularly concerned with improvements in or relating to a valve according to our co-pending United Kingdom Patent Application No. 27237/75 (Serial No.

1 512 385) entitled " Improvements in multiple way- valves ".

On such a multiway valve the surface area of the diaphragm and in some instances the main valve body acted upon from the control valve chamber is greater than the surface area acted upon in the opposite direction at the other end of the main valve body, and in accordance with our co-pending Application the connecting line is designed as an axial through bore in the main valve body, which commences from a first end face located opposite the pressure opening, and the control valve body is central in the control valve chamber and opposite the other end of the through bore.

In our co-pending Application the control valve body, similarly to the main valve body, is suspended resiliently on radial arms, which after overcoming a neutral position, support the movement of the control valve body in the corresponding direction. At this time the control valve body directly seals the mouth of the through bore in the main valve body. Since both valve bodies in order to reach their respective end positions have to be moved towards each other the actuation for the control valve body must be designed to be flexible, so that if the control body effects an overstroke, this will not cause the main valve body to lift off its relevant seat.Since the through bore which communicates with the pressure opening is only closed in the event of a switching operation if, after venting of the control valve chamber, the main valve body is locked in its other end position, then during a considerable part of the venting operation of the control valve chamber, there will be an inflow from the pressure line.

It is an object of this invention to improve the multiway valve in accordance with our co-pending Application in that the valve will be easier to make, will allow an overstroke regardless of the type of actuation, without a leak occurring, and in that the venting operation will largely take place without any inflow.

According to the present invention there is provided a multiway valve including a movable partition defining a main valve chamber wherein a main valve body is supported in an axially adjustable manner, and a control valve chamber wherein is located a controt valve body which is actuated from externally of the valve, the partition having its outer circumference anchored in the valve and being secured to the main valve body, an operating line and a pressure line which open into the main valve chamber, the pressure line, depending on the position of the main valve body, selectively communicating with, or being isolated from, the operating line, a connecting line, which is open to the pressure line, and which extends through the main valve body from a first end thereof adjacent to the pressure line, into the control valve chamber, a tube located in the connecting line in the main valve body and having at one end a seating surface for the control valve body, the tube being biased towards a pre-determined end position in one direction of movement towards the control valve body, but being movable in the opposite direction of movement, a control exhaust line in the control valve chamber which is closed when the control valve body assumes a first end position opening the connecting line, the control valve body opening the control exhaust line when assuming its second end position on the tube seating surface closing the connecting line, and the area of the partition to which pressure is applied from the side thereof facing the control valve chamber exceeding the area on the main valve body to which pressure is applied in the opposite direction, said side of the partition being unrestrained.

With such an improved valve the seat on the tube for the control valve body is movable, which means that the tube can pick up an overstroke caused by the actuating facility acting on the control valve body without this additional movement being passed on to the main valve body.

This also makes it possible to use any actuating medium or facility. The overstroke which in itself is desired, may there fore be kept within a certain tolerance framework. There is a further advantage in that the sealing of the pressure line by means of the control valve body depends only on its speed of actuation, and not also on the speed of venting of the control chamber, so that the pressure line is sealed immediately after actuation and from this point in time no further pressurizing medium can flow in or flow out through the control venting line. This also means quicker venting of the control chamber and therefore a shorter switching time.

An embodiment of the present invention will now be described by way of example only with reference to the drawing, the single figure of which is a longitudinal section through internal components of a multiway valve according to the invention, with a valve casing shown schematically.

Referring to the drawing, a multiway valve 11 comprises a casing 12, shown in chain dotted lines, which has a cylindrical smooth recess 13, and a valve insert 14, which is push-fitted into the recess 13 and is a snug fit, so as to be securely retained in the recess 13. The insert 14 has the form of a cartridge.

As viewed from left to right in the drawing, the valve insert 14 comprises a first ring 16, a member 17 shaped like a spoked wheel, a second ring 18 and a disc-shaped cover 19. The internal space defined by the insert 14 comprises a main chamber 22 and a control valve chamber 24 isolated from one another in a pressure-tight manner by a diaphragm 26. A main valve body 21 is located in the chamber 22 and a control valve body 23 is located in the chamber 24. Valve insert 14 further defines, at one end, an axial pressure opening 27, and at least one operating opening '28 concentrically therewith, at least one radial main vent opening 29 and an axial control vent opening 30 at the other end, these openings being connected to repective pressure, operating or venting apertures in valve casing 12 and from there to respective conduits.The conduits are connected respectively to a source of pressurizing medium, pneumatic or hydraulic units or the outside air.

The pressure opening 27 is formed at the free end of the ring 16 and opens into the main valve chamber 22, which is partly defined by the ring 16. The latter, at its free end, has an O-ring 31 fitted on a support surface and has, on its surface axially opposite the support surface, and facing the main control chamber 22, an annular seating surface 32 which is concentric with pressure opening 27, and which, in a radially outward direction, is angled inwardly of the chamber 22. The main valve body 21 has a seal surface 33 which can mate against the surface 32 in a pressure-tight manner.

On a conical annular section of the ring 16, which faces the valve casing 12 and is concentric with the pressure opening 27, a plurality of evenly distributed apertures are defined, which form the operating openings 28 and which also communicate with the valve chamber 22.

An outer annular section 36 of the member 17, which is shaped like a spoked wheel, and which is made in a single piece from a suitably resilient plastics material, is clamped and held between the two rings 16 and 18. Radial spokes 37 radiate inwardly from the section 36 and these spokes are unitary with a hub 38. The latter forms a covering 38 for a front end 39 of the main valve body 21 and defines the sealing surface 33. The front end 39 of main valve body 21 and the covering 38 are therefore in a positive connection, in that covering 38 grips over the end surface of the main body 21 and in a rearward area by means of an annular arrangement engages in an annular groove on the main valve body 21.

The covering 38 also possesses, at its axial end remote from the seal surface 33 and engaging with the main valve body 21, a rearward seal surface 42, which can mate with a seat 43 on an inwardly projecting part of the second ring 18. The covering 38, which is fitted inside main valve chamber 22, also has an axial hole 44, the diameter of which is less than the diameter of the pressure opening 27, but greater than the diameter of a through bore 46 in the main valve body 21. The bore 46 forms a part of a connecting line 37 between the pressure opening 27, or the pressure opening in valve casing 12, and the control valve chamber 24. As a result of this difference in diameter there are annular front surfaces on the covering 38 and on the main valve body 21, which are exposed to the pressurizing media flowing in through pressure opening 27.

The second ring 18 is provided in a central area with radial bores which are distributed over the periphery, forming the main vent openings 29. Depending on the position of main valve body 21 the openings 29 may communicate with the main valve chamber 22 or be isolated therefrom.

At its end remote from the member 17, second ring 18 has an axial recess 48, in which the diaphragm 26 is inserted. The diaphragm 26 is located with an external ring 49 in the recess 48 and issecured to the main valve body 21 in an annular groove 51. The diaphragm 26, which is formed of a suitable resilient plastics material to allow a floating suspension of the main valve body 21, has a thinner annular zone 52 between, the main valve body connection and the ring 49, and near valve body 21 has an inwardly directed annular notch 53 which allows the diaphragm 26 good mobility. In the area of annular notch 53 and at the opposite side therefrom, the diaphragm 26 engages an end surface of a sleeve 54, which is in positive connection with the main valve body 21, and via which the main valve body 21 is directed towards the remote end of the second ring 18.On the end of the second ring 18 remote from the member 17, the cover 19 is placed, the control vent opening 30 being defined by an axial bore therein. A lug 56 on the cover 19 projects axially inwardly and grips the radially inner surface of the ring 49 of diaphragm 26, so that this is positively and axially held in position. The lug 56 is also profiled on the axially inner surface such that, in the end position other than that shown in the drawing, of main valve body 21, a large area of diaphragm 26 can engage with the lug 56.

The control valve chamber 24 is defined between the cover 19 and the diaphragm 26. Cover 19 also has a broad tapering, axial recess 57 which opens on to the control vent opening 30, ribs 58 being inserted in the recess 57 to direct the control valve body 23, in the shape of a ball. The valve body 23 may, as shown on the drawing, seal control vent opening 30, by butting there against, and may also butt against a seat 59, which is provided at the end of a tube 61 which projects into the control valve chamber 24.

The tube 61 has an axial bore 62 which projects into, to communicate with, through bore 46 in the main valve body 21 and also forms a part of the connecting line 47. The tube 61 has at that end which projects out of the main valve body 21 and into control valve chamber 24, a collar 63, with which it butts against a stop 64 formed by recesses on the ribs 58. The distance between the collar 63 on the tube 1 and the adja- cent end face of the main valve body 21 is, in the end position shown on the drawing, at least as large as the stroke, including a pre-set overstroke, executed by the main valve body 21, when it is moved from one to the other end position.At the other end, the tube 61 is located via an O-ring 66 and an intermediate sleeve 67 on a prestressed compression spring 68, which rests on an annular surface in through bore 46 and, on the one hand, causes tube 61 to be located before the switching operation in the other end position at stop 64, and therefore retain the seat 59 in a specific position relative to control valve body 23, and on the other hand causes the seat 59 for control valve body 23 to be movable, so that on the occasion of the switching operation it is possible to move into the other end position, which is not shown, with an overstroke. The axial distance between the seat 59 on tube 61 and the relevant seal surface of control valve body 23 may be made very short, for example, in the area of 60 to 100 x 1/1000 mm, so that only a very small stroke is necessary to change over the multiway valve 11.

The multiway valve 11 operates as follows: In the drawing, the end position of main control valve body 21 which can be moved backwards and forwards is shown in which the valve body 21 is located at the ring 16 and therefore closes the connection between the pressure opening 27 and the operating openings 28, so that the operating openings 28 communicate with the main vent openings 29.

In addition, connecting line 47 which communicates with the pressure opening 27 also communicates with the control valve chamber 24, so that on the one hand, control valve body 23 is forced by the pressurizing medium against control vent opening 30 and closes the latter, and on the other hand, control valve chamber 24 is under pressure. Since the annular surface of the diaphragm 26 adjacent to the control valve chamber 24, which is acted upon by the pressurizing medium, is greater than the annular surfaces of main body 21 which directly face the pressure opening 27, the main valve body 21 is kept in this end position.

If now the control valve body 23 is forced axially inwards by means of an actuating pin 69, which is shown in the drawing in the form of a dotted line, against the effect of the pressurizing medium in connecting line 47, then on the one hand, the control valve body 23 releases control vent opening 30 and, on the other hand, immediately afterwards since the stroke is very short, closes bore 62 of tube 61 and therefore isolates control valve chamber 24 from pressure opening 27. Control valve chamber 24 is consequently ventilated via control vent opening 30, and basically during this operation there is no further inflow of pressurizing medium through connecting line 47. If actuating pin 69 is afterwards pushed somewhat further in the axial direction, that is to say is moved with overstroke, then tube 61 is pushed against the effect of compression spring 68.In the case of the embodiment shown in the drawing a maximum overstroke of about 0.5 mm is taken into account. With the venting of control valve chamber 24 the pressure on diaphragm 26 also drops, so that the main valve body 21 is pushed by the pressurizing medium axially into its other end position, if the pressure on the annular surfaces of main valve body 21 which face the pressure opening 27 is greater than the pressure pre vailing in control valve chamber 24 and acting on diaphragm 26.

On the occasion of complete venting of control valve chamber 24, the stroke of main valve body 21 is also at an end, after the latter is located with its rearward seal surface 42 on the second seat on ring 18.

This stroke movement on main valve body 21 is further supported after passing a centre position by pre-stressed part 17 which, after passing this centre position, snaps into the other end position. The same also applies to the reverse movement.

This changc-over is therefore effected cxtremely quickly, since in addition the venting of the control valve chamber can also be effccted without any considerable inflow of pressurizing medium.

In this other end position, which is not shown on the drawing, pressure opening 27 communicates via main valve chamber 22 with the operating openings 28, whilst the main vent openings 29 are completely isolated from main valve chamber 22.

Therefore one or several hydraulic or pncumatic operating units may be operated.

If actuating pin 69 is released or if it moves back into its original position, control valve body 23 releases the mouth of the bore in tube 61, and the mouth of connecting line 47, in control valve chamber 24 and locks control vent opening 30 under the effect of the pressurizing medium against control valve body 23. Control valve body 23 is therefore automatically forced into its end position which closes control valve opening 30. When connecting line 47 is opened the pressure medium can again flow into control valve chamber 24, so that main valve chamber 21 is then moved back into its one end position, if the pressure on diaphragm 26 is greater than the pressure on the annular surfaces of main valve body 121 facing pressure opening 27. During this operation tube 61 has also come to be located against the stop in cover 19, if it has first been pushed due to an overstroke.Returnswitching into said one end position is basically effected as quickly, even if there is a specific throttle position between the seat on tube 61 and control valve body 23.

Various modifications may be made without departing from the invention.

WHAT WE CLAIM IS 1. A multiway valve including a movable partition defining a main valve chamber wherein a main valve body is supported in an axially adjustable manner, and a control valve chamber wherein is located a control valve body which is actuated from externally of the valve, the partition having its outer circumference anchored in the valve and being secured to the main valve body, an operating line and a pressure line which open into the main valve chamber, the pressure line, depending on the position of the main valve body, selectively communi cating with, or being isolated from, the operating line, a connecting line, which is open to the pressure line, and which extends through the main valve body from a first end thereof adjacent to the pressure line, into the control valve chamber, a tube located in the connecting line in the main valve body and having at one end a seating surface for the control valve body, the tube being biased towards a pre-determined end position in one direction of movement towards the control valve body, but being movable in the opposite direction of movement, a control exhaust line in the control valve chamber which is closed when the control valve body assumes a first end position opening the connecting line, the control valve body opening the control exhaust line when assuming its second end position on the tube seating surface closing the connecting line, and the area of the partition to which pressure is applied from the side thereof facing the control valve chamber exceeding the area on the main body to which pressure is applied in the opposite direction, said side of the partition being unrestrained.

2. A multiway valve according to claim 1, wherein the tube is supported at one end in the connecting line on a compression spring which is located on a step surface of the connecting line in the main valve body, such that the other end of the tube which projects into the control valve chamber is biased towards a stop.

3. A multiway valve according to claim 2, wherein the stop is formed by radially extending ribs on an end cover for the valve components.

4. A multiway valve according to claim 3, wherein the end cover has an annular lug which projects into the control valve chamber and which has a profile such that, in the respective end position, it forms at least a partial butting surface for the partition, the latter having complementary notches.

5. A multiway valve according to any of

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

line 47. If actuating pin 69 is afterwards pushed somewhat further in the axial direction, that is to say is moved with overstroke, then tube 61 is pushed against the effect of compression spring 68. In the case of the embodiment shown in the drawing a maximum overstroke of about 0.5 mm is taken into account. With the venting of control valve chamber 24 the pressure on diaphragm 26 also drops, so that the main valve body 21 is pushed by the pressurizing medium axially into its other end position, if the pressure on the annular surfaces of main valve body 21 which face the pressure opening 27 is greater than the pressure pre vailing in control valve chamber 24 and acting on diaphragm 26.

On the occasion of complete venting of control valve chamber 24, the stroke of main valve body 21 is also at an end, after the latter is located with its rearward seal surface 42 on the second seat on ring 18.

This stroke movement on main valve body

21 is further supported after passing a centre position by pre-stressed part 17 which, after passing this centre position, snaps into the other end position. The same also applies to the reverse movement.

This changc-over is therefore effected cxtremely quickly, since in addition the venting of the control valve chamber can also be effccted without any considerable inflow of pressurizing medium.

In this other end position, which is not shown on the drawing, pressure opening 27 communicates via main valve chamber 22 with the operating openings 28, whilst the main vent openings 29 are completely isolated from main valve chamber 22.

Therefore one or several hydraulic or pncumatic operating units may be operated.

If actuating pin 69 is released or if it moves back into its original position, control valve body 23 releases the mouth of the bore in tube 61, and the mouth of connecting line 47, in control valve chamber 24 and locks control vent opening 30 under the effect of the pressurizing medium against control valve body 23. Control valve body 23 is therefore automatically forced into its end position which closes control valve opening 30. When connecting line 47 is opened the pressure medium can again flow into control valve chamber 24, so that main valve chamber 21 is then moved back into its one end position, if the pressure on diaphragm 26 is greater than the pressure on the annular surfaces of main valve body 121 facing pressure opening 27. During this operation tube 61 has also come to be located against the stop in cover 19, if it has first been pushed due to an overstroke.Returnswitching into said one end position is basically effected as quickly, even if there is a specific throttle position between the seat on tube 61 and control valve body 23.

Various modifications may be made without departing from the invention.

WHAT WE CLAIM IS 1. A multiway valve including a movable partition defining a main valve chamber wherein a main valve body is supported in an axially adjustable manner, and a control valve chamber wherein is located a control valve body which is actuated from externally of the valve, the partition having its outer circumference anchored in the valve and being secured to the main valve body, an operating line and a pressure line which open into the main valve chamber, the pressure line, depending on the position of the main valve body, selectively communi cating with, or being isolated from, the operating line, a connecting line, which is open to the pressure line, and which extends through the main valve body from a first end thereof adjacent to the pressure line, into the control valve chamber, a tube located in the connecting line in the main valve body and having at one end a seating surface for the control valve body, the tube being biased towards a pre-determined end position in one direction of movement towards the control valve body, but being movable in the opposite direction of movement, a control exhaust line in the control valve chamber which is closed when the control valve body assumes a first end position opening the connecting line, the control valve body opening the control exhaust line when assuming its second end position on the tube seating surface closing the connecting line, and the area of the partition to which pressure is applied from the side thereof facing the control valve chamber exceeding the area on the main body to which pressure is applied in the opposite direction, said side of the partition being unrestrained.
2. A multiway valve according to claim 1, wherein the tube is supported at one end in the connecting line on a compression spring which is located on a step surface of the connecting line in the main valve body, such that the other end of the tube which projects into the control valve chamber is biased towards a stop.
3. A multiway valve according to claim 2, wherein the stop is formed by radially extending ribs on an end cover for the valve components.
4. A multiway valve according to claim 3, wherein the end cover has an annular lug which projects into the control valve chamber and which has a profile such that, in the respective end position, it forms at least a partial butting surface for the partition, the latter having complementary notches.
5. A multiway valve according to any of

claims 2 to 4, wherein a sleeve is located between the tube and the compression spring, the tube engaging against the sleeve via a radial sealing O-ring.
6. A multiway valve according to any of the preceding claims wherein the control valve body is pressed against the control exhaust line by means of the medium flow- ing in the connecting line.
7. A multiway valve according to any of the preceding claims, wherein the components are so arranged that the seating surface on the tube is located in one of its end positions so close to the control valve body that to reach the other end position, a stroke of the control valve body of 60 to 100 x 1/1000 mm is adequate.
8. A multiway valve according to any of the preceding claims, wherein there is defined an annular operating opening which is coaxial to a central pressure opening.
9. A multiway valve substantially as hereinbefore described with reference to the accompanying drawing. ~~