GB2180098A

GB2180098A - Releasable handle assemblies

Info

Publication number: GB2180098A
Application number: GB08617078A
Authority: GB
Inventors: Alec Rushton; Ronald Donnelly
Original assignee: English Electric Co Ltd
Current assignee: English Electric Co Ltd
Priority date: 1985-07-26
Filing date: 1986-07-14
Publication date: 1987-03-18
Also published as: NZ216874A; ZA865414B; GB2180098B; AU575729B2; AU6047886A; IN166664B; GB8518980D0; GB8617078D0

Abstract

A handle assembly (e.g. for a switch fuse) is mounted on an access cover and incorporates means 13 for engaging an actuating member when the access cover is closed, and an intermediate separately rotatable member 7 which normally secures the handle unit against withdrawal from the actuating member in a first position of the handle whilst permitting its release in a second position of the handle, but which can be rotated against a spring after release of locking means 32 into a position which permits withdrawal of the handle unit 13 when in said first position or alternatively prevents its withdrawal when in the second position. <IMAGE>

Description

SPECIFICATION Handle assemblies This invention relates to handle assemblies, more especially, though not exclusively, for operating the mechanism of devices such as switch fuses.

Switch fuses are commonly mounted within an enclosure, having an access cover on which a handle assembly is mounted, the handle being arranged on closure of the cover to engage a spindle oftheswitch fuse mechanism.

Such mechanismscommonlyincorporateaform of interlock to ensure that the cover cannot normally be removed when the switch contacts are closed, but are usually provided with means operable by a suitable tool which releases the interlock should access to the interior of the switch fuse be required, for ex- ample for inspection by an engineer, when in this condition. In some cases also it may be desirableto secure the switch handle in the off position and, at the same time, prevent access to the interior ofthe switch fuse.

An object of the invention is to provide a form of handle assembly which has the above facilities. However the invention is also applicable to handle assemblies employed for operating other devices in which access to the operating mechanism needs to be prevented in certain circumstances.

According, therefore, to the invention, a handle assembly for operating a mechanism comprises a support, a handle unit rotatable with respect to said support and engageable with a co-operating actuating member of said mechanism to effect the oper- ation thereof, an intermediate member rotatable independently ofthe handle unit with respect to said support, releasable locking means arranged to hold the intermediate member normally in a rest position in which it secures the handle unitagainstwithdrawal from the co-operating actuating member in a first position ofthe handle, but permits its release therefrom in a second position ofthe handle, the intermediate member being rotatable, after release of the locking means, to a further position in which the handleunitcan bewithdrawnfromtheactuating memberwhen the handle is in said first position, or alternatively which prevents withdrawal ofthe handle unitfrom the actuating memberwhenthe handle is in said second position.

Preferably the handle assembly incorporates a spring which biases the intermediate member towards said rest position, the member being rotatable into said further position against the spring bias after release ofthe locking means, and the spring subsequently serving to return itto the rest position on release.

Preferably also the locking means comprises a spring-loaded plunger accommodated in a housing on the support and projecting into an opening in the intermediate memberwhen the latter is in the rest position, depression ofthe plungerthrough an arcuate slot in the handle unit releasing itfrom the opening and permitting the intermediate member to be rotated against the spring bias.

The handle unit is preferably secured to the intermediate member by at least one projection extending through an arcuate slot in the intermediate member, and the end of which is shaped so as to engage the rearofthe intermediate member so asto prevent its withdrawal therefrom. In such a case the slot is conveniently formed with a wider section adjacent one end which permits the projection to be in troduced through the slot, rotation of the handle unit causing the end of the projection to engage the intermediate member, and means being provided for preventing the projection from being returned to the wider section of the slot.Such means may be provided by a pin which is fitted into the intermediate memberfollowing engagement by the handle unit and projects into an arcuate slot or groove in the handle unit, the slot allowing a limited degree of rotational movement ofthe intermediate member and handle unit which allows the handleto be rotated sufficiently to actuate the co-operating mech anism, but is insufficient to permit its withdrawal from the intermediate member.

Preferably the handle unit carries two projections which extend through respective diametricallyopposed arcuate slots in the intermediate member.

The intermediate member preferably has a central boss which projectsthrough an opening in the support and is shaped at its end to permit or inhibit the engagement or disengagement ofthe handle unit with the actuating member ofthe mechanism. Pre ferablythe handle unit also has a central boss formed with a bore, non-rotatably engageable with an actuating member in the form of a shaft, the intermediate member being arranged to prevent or allow insertion ofthe shaft into the bore (or its removal therefrom) depending on the relative positions ofthe intermediate member and handle unit.

Preferably the intermediate member is secured to the support by means of a retaining memberwhich is provided with spring fingers resiliently engageable with recesses in the intermediate member.

Where the latter is spring biased towards a rest position the tension ofthe spring may be adjustable by the provision of a plurality of engagement means, such as slots, disposed around the retaining member and with which the spring may be selectively engaged.

The retaining memberthusprovidesthedualfunc- tion of an adjustable tension housing for the spring, and snap-fit retention of the intermediate member on the support.

One handle assembly in accordance with the invention for operating a switch fuse will now be described by way of example with reference to Figures 1 to 6 of the accompanying schematic drawings, in which Figure 1 represents a perspective view of the switch fuse with its enclosure removed, Figures2to4 represent a frontview ofthe handle assembly for actuating the switch mechanism, a sec tional viewofthe handle assembly and a rearviewof the assembly respectively, and Figures 5and 6 illustrates parts of the assembly.

Referring first to Figure 1 ,the switch fuse 1 com- prises a plurality of switch modules M, each of which has contacts which can be simultaneously opened or closed by rotation of an operating bar extending through aligned openings in respective cams, the bar being rotated by means of a square-sectioned forwardly extending shaft 2 coupled to it through bevel gears. Such a switch fuse, the internal details of which are not relevantto the present invention, may be constructed, for example, as described in copending PatentApplication No.8418921.

The switch fuse is arranged to be mounted within an enclosure (not shown) having an open front which is closeable by a door carrying the handle assembly3 which engages the shaft, to enable the switch fuse contacts to be actuated by the handle assembly, when the door is closed.

The handle assembly 3 comprises a bezel 4 in the form of a substantially square moulding arranged to be secured across an opening in the door, and carrying, at its centre, a tubular projection the front ofthe bezel also carrying a forwardly-projecting cylindrical flange 6 coaxially surrounding the tubular projection 5.

Within the flange 6 there is supported an intermediate moulding 7 having a central, rearwardlyprojecting hollow boss 8 which extends through the tubular projection 5 ofthe bezel 4, and a surrounding cylindrical wall 9 which is a close fit within the flange 6. Thewall 9 and the boss 8 are connected by a web 11 having two arcuate slots 12 coaxial with the boss 8 (Figure 5) the function of which will be subsequently described.

A handle unit 13 is located within the intermediate moulding 7 and comprises a circular body having a peripheral wall 15, joined by a flatweb 16 to a raised central section 17 atthefront carrying a handle 20, and to a further rearwardly-projecting cylindrical boss 17' which lies within the boss 8 ofthe intermediate moulding 7.Theweb 16 isformed with a pair of arcuate slots 18, 19. The rear surface ofthe web 16 ofthe handle unit 13 also carries a pairofprojections 21 (Figure 5) having out-turned ends 22. The projections 21 extend through the arcuate slots 12 in the web 11 of the intermediate moulding 7, with the out-turned ends 22 engaging the rear of the web and serving to retain the handle unit 13 within the intermediate moulding.

During assembly the projections 21 are introduced through wider openings 23 at the ends of the respective slots 12 and, following a partial rotation ofthe handle unit 13, an anti-disengagement pin 24 is fitted into a co-operating opening in the web 11 ofthe intermediate moulding so as to project into the arcuate slot 19 ofthe handle unit. The handle unit 13 is thus permitted to rotate partially with respect to the intermediate unit7, within limits prescribed by the pin 24 riding within the slot 19, but is prevented from rotating sufficiently to align the projections 21 with the wider end parts 23 of the slots 12.

The boss 17 ofthe handle unit 13 has a central bore 25 having two diametrically opposed longitudinallyextending grooves 26 which permitthe boss to fit over the end part of the shaft2 of the switch fuse 1, the ends of a pin 27, which extends transversely through the shaft 2, fitting into the grooves 26, so that, as the handle is turned, it rotates the shaft2 and thereby opens or closesthe contacts of the switch fusel.

The end of the boss 8 of the intermediate moulding has an end wall 28 with a central opening 29 having a pair ofdiametrically opposed recesses 31 which normally align with the ends ofthe grooves 26 in one position ofthe handle, which corresponds, in this case, to the "Off" position of the switch fuse contacts Accordingly, when the handle is rotated through 900 to close the contacts withdrawal ofthe handle unit from the switch fuse, a ndhence the opening of the enclosure door, will be prevented by engage- ment of the pin 27 with the end wall 28 ofthe intermediate moulding.

Means are, however, provided to enable the enclosure door to be opened, even when the switch fuse contacts are closed. Thus the bezel 4 carries a cylindrical rearwardly-extending hollow stub 31, which is open at the front and accommodates a spring-loaded plunger 32, which normally projects into an opening 33 in the web 11 ofthe intermediate moulding 7 and holds itin a set position. One end 34 of a coil spring 35, which surrounds the projection 5, is anchored around the stub 31 and the other end 36 is hooked into one of a number of slots 37 in the rim 38 of an annular retaining member39 (see Figure 6) which fits over the end ofthe boss 8, and carries a pairof resilient lugs 41 which spring into opposed recesses 42 in the boss, securing the retaining membertothe boss and preventing its withdrawal from the bezel 4.

Now, should it be desired to open the door of the enclosure with the switch fuse contacts closed, this can be accomplished by depressing the plunger32 with a suitable tool sufficiently to disengage it from the opening 33, this enabling the intermediate moulding 7 to be rotated through 90 againstthe bi- assing action of the spring 35, thereby aligning the recesses 30 in the end wall 28 of the boss 8 of the intermediate moulding with the longitudinal grooves 26 inthe bore ofthe handle unit13.

It may also be desired to lockthe door in the closed position, even where the switch fuse contacts are closed. This can be achieved by depressing the plunger 32 and rotating the intermediate member through 45" to effectively close the ends of the longitudinal grooves 26 when the handle is in the "switch open" position. The handle assembly 13 can be locked in this position, with the switch fuse contacts open and the door locked in the closed position, by means of a padlock passed through aligned holes (notshown) in the flanges 6,9 and 15, ofthe bezel 4, the intermediate moulding 7 andthe handle unit 12.

The plurality of slots 37 around the rim 38 ofthe annular retaining member 39 into which the end 36of the coil spring 35 can be selectively fitted, enables the degree oftension of the spring 35to be adjusted, so thattheretaining member has the dual function of spring tension adjustment as well as providing a snap fit retention of the intermediate moulding 7.

The handle unit may have a ball and stick handle instead ofthe moulded handle illustrated.

Moreover, although the invention is especially applicable to handle assemblies for use with switch fuse it will be appreciated that it may be utilised for otherforms of equipment, where a door or other cover carrying an operating handle assembly is normally required to be secured in the closed position in certain conditions of the equipment.

Claims

1. Ahandleassemblyforoperating a mechanism comprising a support, a handle unit rotatable with respect two said support and engageable with a cooperating actuating member of said mechanism to effect the operation thereof, an intermediate member rotatable independently of the handle unit with respect two said support, releasable locking means arranged to hold the intermediate member normally in a rest position in which itsecuresthe handle unit against withdrawal from the cooperating actuating member in a first position ofthe handle, but permits its release therefrom in a second position ofthe handle, the intermediate member being rotatable after release of the locking means, to a further position in which the handle unit can be withdrawn from the actuating member when the handle is in said first position, or alternatively which prevents withdrawal of the handle unit from the actuating member when the handle is in said second position.

2. A handle assembly according to Claim 1 incorporating a spring biases the intermediate member towards said rest position, the m e m member being rotat- able into said further position against the spring bias after release of tbe locking means, and the spring subsequently serving to return itto the rest position on release.

3. A handle assembly according to Claim 2 comprising a spring-loaded plunger accommodated in a housing onthesupportand projecting into an opening in the intermediate memberwhen the latter is in the rest position, depression ofthe plungerthrough an arcuate slot in the handle unit releasing it from the opening and permitting the intermediate memberto be rotated against the spring bias.

4. A handle assembly according to Claim 1,2 or3 wherein the handle unit is secured to the intermediate member by at least one projection extending through an arcuate slot in the intermediate member, and the end of which is shaped so asto en gagethe rearofthe intermediate member so asto prevent its withdrawal therefrom.

5. A handle assembly according to Claim 4 wherein the slot in the intermediate member is formed with a wider section adjacent one end which permits the projection to be introduced through the slot, rotation of the handle unit causing the end of the projection to engage the intermediate member, and means being provided for preventing the projection from being returned to the wider section of the slot.

6. A handle assembly according to Claim 5 wherein the means for preventing the projection from being returned to the wider end ofthe slot is provided by a pin which is fitted into the intermediate memberfollowing engagement by the handle unit and projects into an arcuate slot or groove in the handleunit,theslotallowing limited degree of rotational movement of the intermediate member and handle unit which allows the handleto be rotated sufficiently to actuate the co-operating mechanism, but is insufficient to permit its withdrawal from the intermediate member.

7. A handle assembly according to Claim 6 wherein the handle unit carries two said projections which extend through respective diametricallyopposed arcuate slots in the intermediate member.

8. Handle assembly according to any preceding Claim wherein the intermediate member has a central boss which projects through an opening in the support and is shaped at its end to permit our inhibit the engagement or disengagement of the handle unit with the actuating member of the mechanism.

9. A handle assembly according to Claim 8 wherein the handle unit has a central boss formed with a bore, non-rotatably engageable with an actuating member in the form of a shaft, the intermediate member being arranged to prevent or allow insertion of the shaft into the bore (or its removal therefrom) depending on the relative positions ofthe intermediate member and handle unit.

10. A handle assembly according to any preceding Claim wherein the intermediate member is secured to the support by means of a retaining member which is provided with spring fingers resiliently en gageablewith recesses in the intermediate member.

11. A handle assembly accordvng to Claim 2 wherein means are provided for adjusting the tension in the biasing spring.

12. A handle assembly according to Claim 11 incorporating a plurality of engagement means disposed around the retaining member and with which the spring may be selectively engaged.

13. A handle assemblyfor operating a switch fuse substantially as shown in and as hereinbefore described with reference to Figures 2 to 6 of the accompanying drawings.

14. A switch fuse incorporating a handle assembly according to any preceding Claim.