GB2272478A

GB2272478A - Latch lever assembly

Info

Publication number: GB2272478A
Application number: GB9224054A
Authority: GB
Inventors: John Rogers
Original assignee: Security & Architectural Hardw
Current assignee: Security & Architectural Hardw
Priority date: 1992-11-17
Filing date: 1992-11-17
Publication date: 1994-05-18
Anticipated expiration: 2012-11-17
Also published as: GB9224054D0; GB2272478A8; GB2272478B

Abstract

A latch lever assembly (10) comprises a handle (11) and a mounting plate (12), the mounting plate (12) having an opening (19) to receive a mounting part (20) of the handle (11), the mounting part (20) and the mounting plate (12) having co-operating formations (30, 31) which permit the mounting part (20) to be inserted into the opening (19) when the handle (11) is in a first rotational position relative to the mounting plate (12), and co-operate to retain the mounting part (20) relative to the mounting plate (12) when the handle (11) is rotated through a predetermined angle, so that no retaining means is required which must be secured to the mounting part (12), but rather, the mounting part (12) of the handle (11) is retained relative to the mounting plate (12) by co-operation of the co-operating formations (30, 31). <IMAGE>

Description

Title: "Latch lever assembly" Description of Invention This invention relates to a latch lever assembly and a method of assembling the same.

A latch lever assembly conventionally comprises a handle which may be a lever or knob, which is rotatable relative to a mounting plate which is secured for example to a door. Rotation of the handle from a rest position in use, is operative to withdraw a latch of a latch mechanism. Usually such a latch lever assembly has a spring to return the handle to its rest position.

Latch lever assemblies are known in which the mounting plate comprises an opening to receive a mounting part of the handle, there being provided a retaining means such as a plate which is secured to the mounting part of the handle by for example, a circlip, rivet or the like to retain the handle relative to the mounting plate.

Such known assemblies are costly to assemble.

According to one aspect of the invention we provide a latch lever assembly comprising a handle and a mounting plate, the mounting plate having an opening to receive a mounting part of the handle, the mounting part and the mounting plate having co-operating formations which permit the mounting part to be inserted into the opening when the handle is in a first rotational position relative to the mounting plate, and co-operate to retain the mounting part relative to the mounting plate when the handle is rotated through a predetermined angle.

Thus no plate or the like retaining means is required which must be secured to the mounting part, but rather, the mounting part of the handle is retained relative to the mounting plate by co-operation of the co-operating formations.

Assembly is thus considerably simplified.

Preferably the opening in the mounting plate is generally circular with a pair of inwardly extending formations, and the mounting part of the handle is provided with a pair of grooves which each co-operate with a respective one of the inwardly extending formations when the handle is rotated from its first rotational position through the predetermined angle.

Preferably, the pair of inwardly extending formations are arranged generally symmetrically around the periphery of a circular opening, and may each extend around about 90" of the opening. The grooves of the mounting part may also be arranged generally symmetrically around an axis of rotation of the handle and where appropriate, may each extend around about 90" of the axis, preferably slightly less, at least one of the grooves having a stop to limit rotational movement of the handle at least in one direction of rotation.

The mounting part may have a pair of recesses symmetrically arranged about the axis and where appropriate, each extending around about 90" of the axis, the recesses permitting the mounting part to be moved axially into the opening when the inwardly extending formations are aligned with the recesses, to a position where the inwardly extending formations of the mounting plate and the grooves of the mounting part are in the same plane, prior to rotation of the handle through the predetermined handle.

The predetermined angle may be only a few degrees.

In another arrangement, instead of the mounting plate having a pair of inwardly extending formations around the periphery of the opening, a single inwardly extending formation may be provided to co-operate with a corresponding groove or the like co-operating formation of a mounting part of the handle.

In each case, preferably the mounting part is provided as a plastic moulding which may be moulded integrally with, or preferably is secured relative to the remainder of the handle, and the mounting plate comprises relatively thin metal whereby the co-operating formations of the mounting part and mounting plate permit free movement therebetween to facilitate rotation of the handle.

Preferably a clearance is provided between the width of the or each groove and the or the respective inwardly extending formation, the clearance being chosen so that there is no significant lateral play between the handle and the mounting plate when assembled.

The latch lever assembly may comprise a spring means which is arranged to return the handle to a rest position after the handle has been rotated from the rest position when the handle and mounting plate are assembled.

Conveniently the spring means comprises a torsion spring helically coiled around the axis of rotation of the handle.

One end of the torsion spring may be retained relative to the mounting part, and the other end of the torsion spring may bear on a bearing surface of the mounting plate whereby rotation of the handle about the axis causes winding of the torsion spring, the torsion spring providing a restoring force to return the handle to the rest position when the handle is released.

The mounting part may include a second peripheral groove having a width substantially similar to the axial thickness of the torsion spring, the torsion spring being retained in the groove. It will be appreciated that when the handle is rotated from the rest position thus to wind the torsion spring, the torsion spring will move into closer co-operation with the groove of the mounting part and thereby provide a further retaining means to retain the handle relative to the mounting part, even in the event that the handle is wound relative to the mounting part during normal operation of the handle, to a position in which cooperating formations of the mounting part and mounting plate could become disengaged.For example, where the mounting part has a pair of symmetrically arranged recesses which can be aligned with each of a pair of inwardly extending formations of the mounting plate, the handle may be rotatable to a position where the inwardly extending formations are aligned with the recesses of the mounting part. However with the spring means in position, the spring means will act as a further retaining means to prevent disengagement between the handle and mounting plate.

According to a second aspect of the invention, we provide a method of assembling a latch lever assembly comprising a handle and a mounting plate, the mounting plate being an opening to receive a mounting part of the handle, the mounting plate and the mounting part having co-operating formations, the method comprising inserting the mounting part into the opening when the handle is in a first rotational position relative to the mounting plate and rotating the mounting part relative to the mounting plate through a predetermined angle to bring the respective co-operating formation into co-operation wherein the mounting part is retained relative to the mounting plate.

The invention will now be described with reference to the accompanying drawings in which: FIGURE 1 is an exploded perspective view of a latch lever assembly in accordance with the invention, FIGURE la is a side elevation of part of the latch lever assembly of figure 1 in an assembled condition, FIGURE 2 is a plan view of the assembly of figure 1, shown assembled.

Referring to the drawings, there is shown a latch lever assembly 10 comprising a handle 11 and a mounting plate 12. The mounting plate 12 is adapted to be secured to, for example, a door, by virtue of openings 13 being provided for fasteners. The mounting plate 12 otherwise comprises a front wall 14, and four upstanding boundary walls 15,16,17 and 18 such that the mounting plate 12 presents a generally open sided box structure.

The front wall 14 has a generally circular opening 19 which is arranged to receive a mounting part 20 of the handle 11. In this example, the handle 11 comprises a manually graspable lever part 21 which is formed integrally, by extrusion or casting, with a spacer part 22 which extends generally perpendicularly to the lever part 21. The spacer part 22 is adapted to receive a mounting part 20 which in this example is provided as a separate moulding.

The lever part 21 and spacer part 22 may be made from, for example, aluminium, or another metal, or indeed even be made in a suitable plastics material. The mounting part 20 is preferably moulded in a plastics material having wear resistant properties, such as nylon, the spacer part 21 being provided with an internal bore 23 which is adapted to receive a post 24 of the mounting part 20 whereby the mounting part 20 can be secured relative to the spacer part 22.

It will be appreciated that if desired, instead of providing a separate mounting part 20, the mounting part 20 could be formed integrally with the remainder of the handle 11, or where the mounting part 20 is provided separately from the remainder of the handle 11, any other suitable means to enable the mounting part 20 to be secured to the remainder of the handle 11 could alternatively be provided.

The mounting part 20 provides a generally square opening 25 which is arranged to receive the normal square cross sectional operating rod of a latch mechanism with which the latch lever assembly 10 is in use, used.

The opening 19 in the mounting plate 12 has a pair of inwardly extending formations 30 which extend inwardly of the periphery of the opening 19 in the front wall 14 of the mounting plate 12. Each inwardly extending formation 30 extends arcuately around the periphery of the opening 19 for approximately 900 and the formations 30 in this example are arranged symmetrically such that they are spaced apart by an arcuate extent of about 90" of the opening 19.

The mounting part 20 is provided with a pair of grooves 31 which also extend arcuately around an axis of rotation A of the handle 11, for an extent of about 90". The grooves 31 are separated by recesses 32 which are provided in the mounting part 20 and are arranged to permit the inwardly extending formations 30 of the mounting plates 12 to be received in the recesses 32 when aligned, to permit the handle 11 to be moved axially along axis A until the inwardly extending formations 30 and the grooves 31 occupy the same plane.

It will be appreciated that when the handle is then turned through a small angle, the inwardly extending formations 30 will be received in the grooves 31, and the handle will thus be retained relative to the mounting part 12.

Referring particularly to figure 2, shown in dotted lines, is the position handle 11 occupies when the mounting part 20 is received in the opening 19 as described.

Shown in full lines is a rest position to which the handle 11 can be moved with the inwardly extending formations 30 received in the grooves 31. The grooves 31 each have a stop 35 which prevent the handle 11 being rotated upwardly i.e. in the direction of arrow B, beyond the rest position 11.

A spring means 36 is provided to return the handle 11 to the rest position after the handle 11 has been used to operate a latch mechanism. The spring means 36 comprises in this example a torsion spring which is helically wound around the axis of rotation A. The spring 36 is helical, an inner end 37 of the spring having a hook formation and being adapted to be received in an opening 38 at the edge of one of the recesses 32, with the spring 36 being wrapped about the mounting part 20, with the other end 39 of the spring bearing on a bearing part 40 of the mounting plate, which comprises an inner surface of wall 17 or 15 depending on the required orientation of the handle 11.

Thus in the event that the handle 11 is moved from the rest position downwards, for example towards the dotted line position shown in figure 2, the spring 36 will become more tightly wound about the mounting part 20 and provide a restoring force to return the handle 11 to the full line rest position when the handle 11 is released.

It can be seen from figure la that the mounting part 20 includes flanges 41 which thus provide a further groove 42 in the mounting part 20. The width W of the groove 42 is preferably arranged to be substantially similar, but slightly greater, than the thickness of the spring 36, such that the spring 36 can be accommodated in the groove 42 particularly when the spring 36 becomes more tightly wound as a result of the handle 11 being moved from the rest position.

Hence in the event that the handle 11 is moved to the dotted line position shown in figure 2, when the recesses 32 and inwardly extending formations 30 will be aligned, there is no risk of the handle 11 becoming detached from the mounting plate 12 because the spring 36 will act as a secondary retaining means to prevent the mounting part 20 passing back through opening 19.

Various further modifications may be made without departing from the scope of the invention.

The mounting plate 12 shown in the drawings is only an example of a suitable configuration of mounting plate. If desired the mounting plate 12 could be of shorter length than that shown which is of the type having a further opening 45 in the front wall 14 to receive a key for a lock for example. The mounting plate 12 need not comprise a box section as shown, but could be of channel shape, with the open ends closed by plastic caps for example, if required.. The mounting plate 12 could, in another arrangement be generally circular in configuration rather than being generally rectangular as shown.

Instead of there being a pair of inwardly extending formations 30 in the opening 19, if desired, an arrangement may be provided with only one inwardly extending formation which may extend for a greater extent around the periphery of the opening than 90 , there being a corresponding formation of the mounting part 20 to receive the single inwardly extending formation.

Although as described, the spring 36 is a helical torsion spring, any other spring means may be provided to return the handle 11 to the rest position.

In another arrangement, it may be necessary to provide some alternative means to prevent the mounting part 20 passing back through the opening 19 in the event that the inwardly extending formation(s) 30 and recess(es) 32 become aligned during normal operation of the handle.

In a conventional latch lever mechanism, the extent of movement of the handle 11 from the rest position is usually restricted such that the handle 11 cannot be moved downwardly from the rest position more than a predetermined amount, namely 55-60 typically. With the arrangement of the present invention, the handle 11 can in fact move virtually through 90" from the rest position. Latch lever mechanisms can become worn, the effect being that the operating rod needs to be rotated through greater than 55-60 in order to retract the latch. With a latch lever assembly 10 in accordance with the invention, by virtue of the handle 11 being permitted to move through a greater angle than 55-60 the latch lever assembly 10 can be used to retract the latch even where the latch mechanism has substantially worn.

The features disclosed in the foregoing description or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A latch lever assembly comprising a handle and a mounting plate, the mounting plate having an opening to receive a mounting part of the handle, the mounting part and the mounting plate having co-operating formations which permit the mounting part to be inserted into the opening when the handle is in a first rotational position relative to the mounting plate, and co-operate to retain the mounting part relative to the mounting plate when the handle is rotated through a predetermined angle.

2. An assembly according to claim 1 wherein the opening in the mounting plate is generally circular with a pair of inwardly extending formations, and the mounting part of the handle is provided with a pair of grooves which each cooperate with a respective one of the inwardly extending formations when the handle is rotated from its first rotational position through the predetermined angle.

3. An assembly according to claim 2 wherein the pair of inwardly extending formations are arranged generally symmetrically around the periphery of a circular opening.

4. An assembly according to claim 3 wherein the formations each extend around about 90" of the opening.

5. An assembly according to claim 3 or claim 4 wherein the grooves of the mounting part are arranged generally symmetrically around an axis of rotation of the handle.

6. An assembly according to claim 5 where appendant to claim 3 wherein the grooves each extend around about slightly less than 900 of the axis, at least one of the grooves having a stop to limit rotational movement of the handle at least in one direction of rotation.

7. An assembly according to any one of claims 2 to 6 wherein the mounting part has a pair of recesses symmetrically arranged about the axis, the recesses permitting the mounting part to be moved axially into the opening when the inwardly extending formations are aligned with the recesses, to a position where the inwardly extending formations of the mounting plate and the grooves of the mounting part are in the same plane, prior to rotation of the handle through the predetermined handle.

8. An assembly according to any one of the preceding claims wherein the predetermined angle is only a few degrees.

9. An assembly according to claim 1 wherein the mounting plate has a single inwardly extending formation provided to co-operate with a corresponding groove or the like co-operating formation of the mounting part of the handle.

10. An assembly according to any one of the preceding claims wherein the mounting part is provided as a plastic moulding which may be moulded integrally with, or secured relative to the remainder of the handle, and the mounting plate comprises relatively thin metal whereby the co-operating formations of the mounting part and mounting plate permit free movement therebetween to facilitate rotation of the handle.

11. An assembly according to any one of claims 2 to 10 where appendant to claim 2 wherein a clearance is provided between the width of the or each groove and the or each respective inwardly extending formation, the clearance being such that there is no significant lateral play between the handle and the mounting plate when assembled.

12. An assembly according to any one of the preceding claims wherein the latch lever assembly comprises a spring means which is arranged to return the handle to a rest position after the handle has been rotated from the rest position when the handle and mounting plate are assembled.

13. An assembly according to claim 12 wherein the spring means comprises a torsion spring helically coiled around the axis of rotation of the handle.

14. An assembly according to claim 13 wherein one end of the torsion spring is retained relative to the mounting part, and the other end of the torsion spring bears on a bearing surface of the mounting plate whereby rotation of the handle about the axis causes winding of the torsion spring, the torsion spring providing a restoring force to return the handle to the rest position when the handle is released.

15. An assembly according to claim 13 or claim 14 wherein the mounting part includes a peripheral spring groove having a width substantially similar to the axial thickness of the torsion spring, the torsion spring being retained in the spring groove.

16. A latch lever assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

17. A method of assembling a latch lever assembly comprising a handle and a mounting plate, the mounting plate having an opening to receive a mounting part of the handle, the mounting plate and the mounting part having co-operating formations, the method comprising inserting the mounting part into the opening when the handle is in a first rotational position relative to the mounting plate and. rotating the mounting part relative to the mounting plate through a predetermined angle to bring the respective co-operating formation into co-operation wherein the mounting part is retained relative to the mounting plate.

18. A method of assembling a latch lever substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

19. Any novel feature or novel combination of features as herein defined and/or shown in the accompanying drawings.