GB2221973A

GB2221973A - A hydraulic valve

Info

Publication number: GB2221973A
Application number: GB8822565A
Authority: GB
Inventors: Werner Deterding
Original assignee: Schmidt & Co Kranz GmbH
Current assignee: Schmidt & Co Kranz GmbH
Priority date: 1988-08-19
Filing date: 1988-09-26
Publication date: 1990-02-21
Also published as: DE8810491U1; GB8822565D0

Abstract

In a manually-operated valve controlled by a rotatable member 4 connected to a hand grip 13 which may be turned manually from a predetermined position, the grip is resiliently biased to return to the predetermined position when released. In the preferred embodiment the valve is hydraulic and the hand grip (13) has provision for limited rotation relatively to the valve body (2). To this end, stop pins (20, 21) subject to the action of a helical torsion spring (17) are disposed in the valve body (2) and in the hand grip (13) respectively. Rotation of the hand grip (13) in either direction away from a central position tensions the helical torsion spring (17). Upon release of the hand grip the restoring force provided by the helical torsion spring returns the hand grip to its central position. Maximum rotation of the hand grip is limited by means of a disc (9), rotatable with the hand grip and formed with arcuate slot (22) through which the stop pin (20) extends. <IMAGE>

Description

Description of Invention Title: "A hydraulic valve" THE INVENTION relates to a valve, such as a hydraulic valve having a valve body and a rotatable control member connected to a hand grip which can be turned away from and towards a predetermined angular position relative to the valve body, to control the valve.

A hydraulic valve of this kind is of use, for example, in a hydraulic rock-bolting column drill for drilling holes in the rock in underground mining. The holes can then be used inter alia to secure rock bolts or to take samples of rock or to detect dangerous gases.

They can also be used to receive explosive cartridges or for infusion devices.

By rotating the grip relatively to the valve body one load connection can be connected to the hydraulic fluid flow line, so that the hydraulic fluid is supplied to at least one hydraulic load, while the other hydraulic load connection, to which at least one hydraulic load can also be connected, is connected to the hydraulic fluid return line.

When the grip is turned in the other direction, the load connections are first separated from the flow line connection and return connection. As the grip is turned further into its other end position, the flow line is connected to the load connection previously connected to the return line while the load connection previously connected to the flow line is now connected to the returns line.

The hand grip remains in its end positions, possibly through the agency of appropriate locking or catch means, until the grip is deliberately turned back into its neutral central position or into the other operation position.

More particularly in the case of the rock-bolting column drills hereinbefore referred to, hydraulic valves of the kind of interest in the present connection form part of grips which while in practical use are subjected to continuously changing tensions and compressions by the miners. The valves must be moved into the central position to ensure that unwanted operations are not initiated or carried out. The miner must therefore effect an intentional operation of the valves, something which is often difficult.

It is the object of the invention to provide an improved manually operable valve which will automatically return to a predetermined position unless deliberately kept in another position by a manually applied force.

According to one aspect of the invention, there is provided a manually operable valve having a valve body and a rotatable control member connected to a hand grip which can be turned away from and towards a predetermined angular position relative to the valve body, for control of the valve and wherein said hand grip is resiliently biased towards said predetermined angular position whereby it may be turned manually from said predetermined position against the resilient bias and will return to said predetermined position, under said bias, when released.

In a preferred embodiment, in which the valve is a hydraulic valve used for controlling a rock drill, in mining, the predetermined position is a central position and the hand grip can be turned in one direction from the central position to one end position, to connect one load connection to a hydraulic pressure line and another load connection to a hydraulic return line or can be turned in the opposite direction from the central position, to another end position, to connect said other load connection to the hydraulic pressure line and said one load connection to the return line.In operation of this preferred embodiment, when the grip is rotated into either of the end positions - i.e., positions in which either one of the load connections is connected to the flow line and, in parallel thereto, the other load connection is connected to the return line -a resilient restoring element is tensioned. When the grip is released, the restoring force of the restoring element, which has built up because of the tension, ensures that the grip returns automatically to the neutral central position in which there is no communication between, on the one hand, the load connections and, on the other hand, the flow and return lines.

This automatic movement of the grip to the central position is very advantageous in rock-bolting column drills which have hydraulic motors and hydraulic cylinders and in which the hydraulic valves are installed at the ends of the grip, which can be operated at two ends. The miner can now exert compression and tension manually during the rotating actuations. Unless the miner deliberately keeps the valve in one or other of the end positions a return of the valve to its central position is ensured.

The resilient restoring element is preferably a helical torsion spring. A spring of this kind is simple to produce and can be assembled in a reduced space.

Preferably the spring has at least one turn extending around an inner socket of the hand grip, the socket extending parallel to the grip axis, and the spring ends which are so bent as to extend radially and parallel to one another, extend adjacent two abutments, one abutment being secured in the valve body and the other being secured in the hand grip.

In the preferred embodiment, a relatively reduced movement of the grip relatively to the valve body suffices to tension the helical torsion spring and thus to build d up the restoring or returning force. This feature also ensures that the hand grip returns to the central position from any position into which it has been turned from the central position.

The abutments for the radially directed ends of the helical torsion spring can be embodied in a variety of ways. Preferably, these abutments are in the form of pins which extend parallel to one above another and parallel to the rotational axis of the hand grip. Stop pins of this kind, in addition to being easy to manufacture, can be readily located in corresponding apertures in the valve body and in the hand grip.

Location can be affected by pressing-in or welding-in or sticking-in.

Preferably the spring and stop pins are received in an annular, e.g. turned-in, groove formed in the hand grip. The turned-in groove is in this case bounded by the inner socket of the hand grip, such socket being operative to secure the same on a journal of the control member, and by the sleeve-like outer envelope or casing of the hand grip. Such envelope or casing extends with relatively reduced clearance over a cylindrical longitudinal portion of the valve body and thus prevents particles from entering the spring-receiving groove.

Preferably a disc is clamped co-rotatably between the hand grip and the control member and is formed with an arcuate slot through which the abutment secured to the valve body extends with provision for relative movement.

The arcuate slot provided in the co-rotatably clamped disc is operative to limit the end positions of the hydraulic valve i.e. the positions in which one of the load connections is connected to the flow line and the other load connection to the return line.

An embodiment of the invention is described in greater detail below with reference to the accompanying drawings, wherein: Figure 1 shows a hydraulic valve in a diagrammatic vertical longitudinal section; Figure 2 is a cross-section on the line II-II of Figure 1; and Figure 3 is a cross-section on the line III-III of Figure 1.

Referring to Figure 1, a hydraulic valve 1 is installed, for example, at the ends of a grip which can be gripped at either end and which is a part of a hydraulic rock-bolting column drill used in undergrounding mining. The hydraulic loads of such a drill are, for example, a hydraulic motor and a hydraulic cylinder.

Valve body 2, which has a rectangular external contour, has internally a control member 4 which is rotatable around an axis 3 and which is not shown in further detail. By an appropriate movement of the member 4 a connection P for a hydraulic flow line can be connected either to a connection V for one hydraulic load or to a connection V1 for the other hydraulic load.

Whichever load is not connected to the flow line connection P is, in this position of the control member 4, connected to the return line connection V or V1.

A stepped journal 5 of the control member 4 extends out of the valve body 2. The larger-diameter part 6 of the journal 5 is in sealing-tight relationship with the valve body 2 by way of a seal 7.

As is apparent from Figure 2, a disc 9 is pushed on to the end part 8 of journal 5 as far as a shoulder 10 on part 6 and is secured rotatably by means of a feather or tongue or the like 11.

Also, an inner socket 12 of a tubular hand grip 13, the socket 12 extending parallel to the axis of the grip, is engaged substantially without clearance on terminal part 8 of the journal. The grip 13 is secured by means of a screw 14 which extends through a bore in grip base 15 on axis 3 and is secured into a tapped bore (not shown) in part 8. The securing of the grip 13 also secures the disc 9 on the journal 5. The feather or tongue 11 is also operative to secure the grip 13 co-rotatably on journal end 8.

Turns 16 of a helical torsion spring 17 extend around the inner socket 12 (see also Figure 3). Ends 18, 19 of spring 17 are bent radially parallel to one another and extend adjacent two stop pins 20, 21, one secured in valve body 1 and the other in the grip 13. The pins 20, 21 extend parallel to and one above the another and parallel to rotational axis 3 of grip 13. The pins 20, 21 are of a length such that the two ends 18, 19 of the spring 17 extend into the zone of action of the pins 20, 21.

The pin 20 secured in the valve body 2 also extends through a curved aperture 22 in disc 9. Axis 23 of aperture 22 extends in a circle around rotational axis 3 of grip 13.

As will be apparent, envelope 24 of hand grip 13 engages sealingly over a cylindrical terminal part 25 of valve body 2, thus preventing dust and other particles of dirt from entering the groove 26 between the inner socket 12 and the envelope 24.

When the grip 13 is turned to provide communication between the flow connection P and one of the load connections V or V1, the spring 17 is simultaneously tensioned since the stop pin 21 entrains spring end 18 or 19 while the other spring end 19 or 18 remains retained by the stop pin 20 secured in the valve body 2. The grip 13 can be rotated until the pin 20 abuts the end of the aperture 22.

When the miner releases the grip 13 in this position, the restoring force arising from rotation of the spring 17 automatically produces a restoring or return moment, with the result that the grip 13 returns to the neutral central position of the control member 4 as shown in Figures 1 to 3.

The circumstances hereinbefore described apply to both directions of rotation of the grip 13.

Claims

CLAIMS:

1. A manually operable valve having a valve body and a rotatable control member connected to a hand grip which can be turned away from and towards a predetermined angular position relative to the valve body, for control of the valve and wherein said hand grip is resiliently biased towards said predetermined angular position whereby it may be turned manually from said predetermined position against the resilient bias and will return to said predetermined position, under said bias, when released.

2. A hydraulic valve whose body has a connection for a hydraulic flow line, a connection for a return line and two separate connections for hydraulic loads, a rotatable control member which is connected to a hand grip being disposed in the body and being adapted to connect the load connections alternately to the flow line connection and to the return line connection, in which the valve body (2) and the hand grip (13) are so interconnected by way of a resilient return element (17) as to be rotatable relatively to one another.

3. A valve according to claim 2, in which the return element (17) is a helical torsion spring.

A A valve according to claim 3, in which the spring (17) has at least one turn (16) extending around an inner socket (12) of the hand grip (13), the socket extending parallel to the grip axis, and the spring ends (18, 19) which are so bent as to extend radially and parallel to one another, extend adjacent two abutments (20, 21), one abutment being secured in the valve body (2) and the other being secured in the hand grip (13).

5. A valve substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

5. A valve according to claim 4, in which the abutments (20, 21) are in the form of pins which extend parallel to one another and parallel to the rotational axis (3) of the hand grip (13) and which lie one above the other.

6. A valve according to claim 4 or claim 5, in which the spring (17) and the stop pins (20, 21) are engaged in a groove (26) turned in the hand grip (13).

7. A valve according to any of claims 4 to 6, in which a disc (9) is clamped co-rotatably between the hand grip (13) and the control member (4) and is formed with an arcuate slot (22) through which the abutment (20) secured to the valve body extends with provision for relative movement.

8. A valve substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

9. Any novel feature or combination of features disclosed herein.

Amendments to the claims have been filed as follows CLAIMS: 1. A hydraulic valve whose body has a connection for a hydraulic flow line, a connection for a return line and two separate connections for hydraulic loads, a rotatable control member which is connected to a hand grip being disposed in the body and being adapted to connect the load connections alternately to the flow line connection and to the return line connection, in which the valve body and the hand grip are so interconnected by way of a helical torsion spring as to be rotatable relatively to one another, and in which the spring has at least one turn extending around an inner socket of the hand grip, the socket extending parallel to the grip axis, and the spring ends which are so bent as to extend radially and parallel to one another, extend adjacent two abutments, one abutment being secured in the valve body and the other being secured in the hand grip.

2. A valve according to claim 1, in which the abutments are in the form of pins which extend parallel to one another and parallel to the rotational axis of the hand grip and which lie one above the other.

3. A valve according to claim 1 or claim 2, in which the spring and the stop pins are engaged in a groove turned in the hand grip.

4. A valve according to any of claims 1 to 3, in which a disc is clamped co-rotatably between the hand grip and the control member and is formed with an arcuate slot through which the abutment secured to the valve body extends with provision for relative movement.