The present invention relates to an operating device for a rotatable member, particularly although not exclusively, a spindle of a ball valve.

Ball valves are commonly used as shutoff valves on road tanker vehicles for the delivery of hazardous liguids where there is a pollution and/or explosion risk, such as e.g. petroleum, liquified petroleum gas (LPG), fuel oils. Hence, there is a need to guard against the accidental or unauthorised operation of the valve.

Furthermore, such valves are frequently designed with a relatively short valve spindle, consequently it is difficult to attach a valve operating device securely thereto. Moreover, a poorly fitting valve operating device will exacerbate any wear problems associated with the valve and might well reduce the effectiveness of the security provided by the device.

Accordingly, it is an object of the present invention to provide a solution to the problems of mechanical wear and security of operation set out above, and which additionally provides improved ergonomics, and is simple to produce and maintain.

According to the invention there is provided an operating device for connection to a rotatable member, for example a valve spindle, comprising a drive unit securable to the rotatable member by locking means, and a generally tubular casing which encompasses the drive unit and which incorporates a part-circumferential slot to provide access, in use, to a mating surface on the drive unit for a drive unit engaging portion of a detachable operating handle, such that rotation of the handle causes corresponding

rotation of the rotatable member between open and closed positions.

Preferably the slot is so dimensioned that the handle when received by the drive unit is prevented from removal in all but the closed position or, indeed, any other position or positions required for the particular application of the device. Advantageously, this may be achieved by reducing the width of the slot to less than that of the drive unit engaging portion of the handle. Preferably, the mating surface of the drive unit has a profile intended for connection to a complementary surface formed in the engaging portion of the handle. Advantageously, a complementary groove and slot may be formed in respective ones of the surfaces. Furthermore, the operating handle may be formed with a crank to provide smooth and positive operation and thereby reducing load on the device and rotatable member.

The drive unit locking means may take the form of a locking ring which is urged into abutment with the drive unit by a locknut. Alternatively, the locking ring may be omitted and the locknut instead formed with a tapered portion which abuts a corresponding shoulder formed on the drive unit, in which case, during assembly on to for example, a valve spindle, tightening of the locknut against the drive unit causes internal threads of the locknut to collapse unto the thread of the valve spindle.

An embodiment of the present invention will now be described, by way of example and with reference to the accompanying drawings, in which:

Figure 1 is an exploded view of an operating device according to the invention, shown in conjunction with a corresponding assembly tool and operating handle;

Figure 2 is a plan view of a casing of the device of Figure 1;

Figure 3 is a cross-sectional side view on the line II-II of the casing of Figure 2;

Figure 4 is a partially-sectioned side view of a drive unit of the device of Figure 1;

Figure 5 is a cross-sectional plan view on the line V- V of the unit of Figure 4;

Figure 6 is an underside view of the unit of Figure 4;

Figure 7 is a side view of a tubular nut of the device of Figure 1;

Figure 8 is a partially-sectioned side view of a cover of the device of Figure 1;

Figure 9 is a partially-sectioned side view of the device of Figure 1 shown assembled;

Figure 10 is a partially-sectioned side view of a variant of the drive unit of the device of Figure 1;

Figure 11 is a side view of a variant of the tubular nut of the device of Figure 1;

Figure 12 is a partially-sectioned side view of an assembled device showing the variant of the drive unit and tubular nut;

Figure 13 is a cross-sectional side view of a handle as shown in Figure 1; and

Figure 14 is a cross-sectional plan view of the handle of Figure 13.

The operating device l shown in the Figures is intended for use with a valve, and comprises a tubular steel casing 10, which houses within its bore 12 a drive unit 14 which is securable, in use via rectangular aperture 16 over flats of a spindle of a ball valve (not shown). The drive unit 14 is fixedly held, in use, on the valve spindle by a locking ring 18 and locknut 20, access to which is prevented by a cover 22 fastened by grub screws 24 which pass radially through tapped holes 26 in the casing

10 to engage in a circumferential recess 28 in the cover 22.

The casing 10 is provided with a part-circumferential slot 30 which provides access, in use, for an operating handle 32. The slot 30 has a portion 34 of reduced width for at least part of its extent such that the operating handle 32, once inserted thorough the slot 30 at an entry position 36 having a relatively large width, cannot be removed from the device l when it has been rotated sufficiently to bring the handle 32 into the reduced width portion 34. The operating handle 32 has a mating surfaces 38 which are engagable on corresponding spanner flats 40 formed in the surface of the drive unit 14. A raised rib 42 on the spanner flats 40 allows only complementary shaped mating surfaces 38 having grooves 39, to engage with the drive unit 14.

The operating device 1, is assembled for use on a valve spindle (not shown) by inserting the grub screws 24 in to the tapered holes 26 in the casing 10 so that they are engaged in their threads, but do not protrude into the bore 12 of the casing 10. The drive unit 14 is then inserted into the bore 12 of the casing 10 and allowed to slide down the bore 12 until the underside of the unit 14 locates on a step 46 formed within the bore 12. Spacers 13 may be used to ensure the device is seated correctly on the valve. The unit 14 should be orientated relative to the casing 10 so that the spanner flats 40 are at right angles to the slot 30 in the casing 10 at the position 36 where the operating handle 32 is inserted.

The combination of the casing 10 and drive unit 14 are then placed over the valve spindle such that rectangular aperture 16 of the drive unit engages on the valve spindle.

The drive unit 14 is then fixed to the valve spindle by sliding the locking ring 18 down the valve spindle such that its convex side is uppermost (as shown in Figure 1) and then winding the locknut 20, with its slotted portion 48 uppermost down the thread on the spindle such that its underside 50 contacts the top of the locking ring 18. An assembly tool 52 (as shown in Figure 1) comprising a tubular spanner 54 and bolt 56 is then located such that a raised portion 58 of the tubular spanner 54 engages with the slotted portion 48 of the locknut 20 and the bolt 56 locates the spanner 54 on the nut 20. The drive unit 14 is then locked in position in the conventional manner by securing the unit 14 against rotation using the operating handle 32 on the spanner flats 40 and tightening the locking ring 18 and nut 20 against the unit 14 with the tubular spanner 54. Once the unit 14 has been fixed to the spindle, the assembly tool 52 is removed, and access to the locking arrangement is prevented by fitting the cover 22 to the casing using the grub screws 24.

In a variant of the above described embodiment, the locking ring 18 and locknut 20 are replaced by a barrel locknut 120 as shown in Figures 10, 11 and 12. The barrel locknut 120 is provided with a tapered end portion 160 which is forced against a correspondingly shaped shoulder 162 within the bore 112 of the casing 110 until the internal thread 119 of the locknut 120 collapses onto the thread of the valve spindle when tightened by the tubular spanner in the manner described above.

It will be appreciated by one skilled in the art that the device may be used not only with a valve but in other form of switch incorporating a rotatable member. Moreover, the device may have applications where the handle should be removable at a position or positions other than fully closed. For instance, in the case of a sprinkler valve.

the handle should be removable in the fully open position only. Furthermore, in order to prevent unauthorised operation when the handle is engaged with the drive unit, the device may be provided with suitable locking means, such as a padlock, to retain the handle in engagement with the device. Thew ability to lock the handle in a particular position would be particularly advantageous in the case of a valve where the valve is required to be held at a partially open position, and hydrodynamic forces would otherwise tend to open (or close) the valve.