GB2194281A

GB2194281A - Door handle mechanism

Info

Publication number: GB2194281A
Application number: GB08717636A
Authority: GB
Inventors: Michael George Mander
Original assignee: WJ Goodwin and Son Ltd
Current assignee: WJ Goodwin and Son Ltd
Priority date: 1986-08-21
Filing date: 1987-07-24
Publication date: 1988-03-02
Anticipated expiration: 2007-07-24
Also published as: GB2194281B; GB8620354D0; GB8717636D0

Abstract

A door handle mechanism includes a backplate (10), an operating handle (14) journalled in the backplate and a cam member (30) on the part of the handle within the backplate. Within the backplate and extending on opposite sides of the cam member is a flat, slidable plate (19) having upturned ends (20, 21). At one side of the cam member is a spring housing (35), with springs (37) which contact one of the upturned ends (20) of the plate to force the housing against the cam member. At its other side, the cam member contacts a bearing block (38) received against the other upturned end (21) of the plate, which is forced downwardly by the springs. In a horizontal rest position of the handle flats on the cam member engage the spring housing and 37 bearing block respectively. On rotation of the handle from the rest position two lobes on the cam member force the spring housing downwardly and the plate upwardly, the two operations compressing the springs. Release of the handle causes it automatically to be returned to its rest position by expansion of the springs. A snib arrangement is also provided releasably to lock the handle in a particular angular position by, arms (45) on a manually operable snib plate engaging shoulders on the cam member. <IMAGE>

Description

SPECIFICATION Door handle mechanism This invention relates to a door handle mechanism and has as its object the provision thereof in an effective and convenient form.

According to the invention a door handle mechanism comprises a backplate, an operating member mounted on the backplate for angular movement relative thereto with an end part thereof received in the backplate, said end part having a member thereon, an element received in the backplate and extending on opposite sides of the operating member end part, biasing means at one side of the end part and acting between said member on the end part and part of said element at said one side of the end part, angular movement of the operating member causing said member on the end part directly or indirectly to move the element relative to the backplate, with said biasing means acting against said movement.

Preferably angular movement of the operating member causes said member on the end part directly or indirectly to act on part of said element at the other side of the end part.

Desirably the member on the end part has a cam surface which indirectly engages said element to effect said movement thereof upon angular movement of the operating member.

Advantageously the member also has at least one engagement surface with which a snib element can engage releasably to retain the operating member in a particular angular position relative to the backplate.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a fragmentary rear view of a door handle mechanism of the invention, Figure 2 is a part-sectional longitudinal side view of the mechanism shown in Figure 1, Figure 3 is a plan view of a slidable plate of the mechanism, Figure 4 is a cross-sectional view on the line 4-4 of Figure 3, Figure 5 is a side view of a cam member of the mechanism, Figure 6 is a view on the arrow A of Figure 5, and Figure 7 is a pian view of a snib plate of the mechanism.

The door handle mechanism shown in Figures 1 and 2 comprises a conventional channel-section backplate 10 having its ends closed by end caps 11, only one of which is shown. The backplate has a circular aperture 12 through its channel base to receive a cylindrical spigot 13 of a lever door handle 14 in the usual manner, a bearing bush 15 being disposed around the spigot adjacent its junction with the shank of the handle, the bush 15 being in engagement with the outer face of the backplate.

At a position flush with the interior surface of the backplate, the spigot 13 is formed with two diametrically opposed flats 16 which extend to the free end of the spigot. Spaced just inwardly from said free end is an annular groove 17 in the spigot and at 90" around the spigot from the flats are a pair of diametrically opposed grooves 18 of V-shaped cross-section, the sides of the V-shape lying at 45" to a diametral plane of the spigot parallel to the flats. The grooves extend along the spigot by the same amount as the flats.

Received in the backplate is a plate 19 (Figs. 3 and 4) which is generally flat and has a width substantially matching that of the interior of the backplate. The plate has its ends 20, 21 respectively turned up through 90 and has an aperture 22 in its main part through which the spigot 13 extends, the aperture having arcuate end portions 23, 24 and parallel straight sides 25, so that it extends someway below the spigot in order to permit the plate to slide relative thereto as will be described. The rear surface of the plate is received on the interior surface of the backplate so that it is also substantially flush with the inner ends of the flats 16.

The upturned end 20 of the plate has three aligned pips 26 on its inwardly facing surface, the pips being spaced across its width. The opposite end 21 has a central slot 27 and is also formed with slots 28, 29 at its respective outer sides, each slot extending from the end 21, across its junction with the flat main part of the plate 19 and into the plate itself.

Fitted on the spigot 13 is a generally oval shaped, sintered iron cam member 30 (Figs. 5 and 6), having a central aperture which matches the outer surface of the spigot, so that the cam member is a tight fit thereon. One side surface 31 of the cam member 30 abuts the interior surface of the plate 19, as shown in Figure 2. Its opposite side surface 32 is abutted by a circlip 31 in the groove 17.

The cam member has a pair of diametrically opposed, thickened lobes aligned with the grooves 18, the outer surface of each lobe between the side surfaces 31, 32 forming a cam surface. The cam member has diametrically opposed flat surfaces 33, 34 respectively between the lobes, the surfaces 33, 34 thus being parallel to the flats 16 on the spigot 13.

Below the cam member, a rectangular spring housing 35 of plastics material is contained in the backplate. The housing is closed at its top by a flat surface 36 against which the lower flat surface 34 of the cam member engages.

The housing 35 has three vertical, parallel chambers therein which are open to the bottom of the housing. These chambers contain compression springs 37 extending out of the housing and engaging over the pips 26 respectively on the inwardly facing surface of the end 20 of the plate 19, the springs forc ing the surface 34 against the cam member.

On the plate 19 and with one of its iong sides abutting the end 21 thereof, is a rectangular bearing block 38. Its other long side is engaged by the upper flat surface 33 of the cam member. The block 38 has respective slots at its lower edges to match the adjacent parts of the slots 28, 29 in the end 21 of the plate 19. Projecting from the centre of the surface of the block which abuts the plate end 21 is a location peg 39 which extends through the slot 27 and somewhat therebeyond.

Above the plate end 21, the backplate has a central, longitudinally extending slot 40. A snib knob 41 on the outside of the backplate has a shank 42 extending through the slot 40 and through a hole 43 in a portion of a bifurcated locking or snib plate 44 (Fig. 7) which is dished towards the interior surface of the backpiate. The end of the shank is spread to secure it to the plate 44.

The remainder of the plate 44 is raised off the interior surface of the backplate at the level of the slots 28, 29 in the end 21 and aligned slots in the block 38. Two arms 45 of the plate 44 extend along respective opposite interior sides of the backplate and through the aligned slots in the end 21 and block 38, to terminate just short of the cam member 30, when the handle 14 is at 90" to the backplate as shown in Figures 1 and 2. Between the arms is a weak compression spring 46, having its one end on a central lug 47 bent outwardly from the plate 44, and its other end on the peg 39.

The end surface of each arm 45 is formed with an inclined portion 48 ieading to a straight portion 49, which is vertical, in use.

The side surface 31 of the cam member has four equi-angularly spaced portions cut away to provide respective flat shoulders 50 in the plane of the arms 45. With the handle 14 at 90" to the backplate as shown in Figures 1 and 2, the two flat ypper shoulders lie almost parallel to the inclined portions 48 of the respective adjacent arms. The two lower shoulders are disposed so that all four shoulders are symmetrical about said diametrai plane through the spigot parallel to the flats.This geometric arrangement of surfaces 48, 49 of the arms, and shoulders 50 is such that if the handle 14 is angularly moved by about 50 one opposite pair of shoulders 50 become vertically positioned facing the respective interior side surfaces of the backplate, so that if the arms 45 are moved vertically downwards from the Figures 1 and 2 positions, they firstly engage the respective vertical shoulders 50 with the surfaces 48 and then surfaces 49, so as releasably to lock the cam member, and thus the handle, in position, when the handle is released, the arms being tightly held between the cam member and the respective sides by the backplate.In this position the bias of the spring housing 35 will force the cam member to a position where the shoulders are slightly off vertical, the exactly vertical shoulder position actually allowing sliding of the arms.

Operation of the handle mechanism will now be described with it secured to one side of a door with a spindle received in the usual square recess 51 in the end of the spigot 13 to operate a latch bolt.

From the horizontal handle rest position of Figures 1 and 2, it is possible angularly to move the handle to retract the latch bolt. Normally the handle movement required is downwards, although if required the latch arrangement could be such as to require upward movement. In either event the handle movement causes the cam surfaces of the lobes to engage the block 38 and spring housing 35 respectively. Such engagement forces the block upwardly and the housing downwardly.

Upward movement of the block 38 is transmitted to the plate end 21 which thus causes the whole plate 19 to slide along the interior base surface of the backplate, with the slot 22 in the plate catering for the relative movement between the plate and the handle spigot. The springs 37 are thus compressed both by the downward movement of the housing 35 and the upward sliding movement of the end 20 of the plate 19. The number, arrangement and strengths of springs or other biasing means can be varied as required.

As the end 21 of the plate moves upwardly it compresses the weak spring 46, with the arms 45 being received through the slots 28, 29 and the slots in the block 38. The bearing block 38 is prpvided to prevent wear of the cam member surfaces against the metal plate end 21. Release of the handle allows it to be automatically returned to its rest position by the bias of the springs 37 which force the housing upwardly and plate 19 downwardly.

It will be appreciated that handing of the mechanism can be easily attended to on site, since before engaging the mechanism with the latch bolt, the handle can be rotated through 1800, the movement through 90" taking the cam member through its extreme overcentre position, where maximum spring compression occurs. The symmetrical arrangement of the cam lobes and the shoulders 50 is designed for such ease of handing.

As already described, a 50 movement of the handle brings the cam member to a position where two vertically positioned shoulders 50 are provided. If the knob 41 is then slid downwardly, downward movement of the bifurcated plate 44 is produced and the arms 45 slide through the slots 28, 29 in the end 21 and the slots in the block 38 to engage the respective shoulders as described on release of the handle. The release of the handle at this time will allow some initial slight restoring rotation of the handle to take place due to the bias on the handle, but it will thereafter remain held in this downward position. Release of the handle can be effected either by sliding the knob 41 manually upwardly under its light spring force or by initially manually pushing the handle 14 slightly downwardly to bring the shoulders vertical resulting in the release of the engagement of the arms, which are then automatically moved upwardly under the action of the spring 46.

The spring 46 is much weaker than the springs 37 and in some instances it may be omitted, with the snib having to be released manually.

The particular geometry of the arms and shoulders ensures a positive locking of the handle upon snib operation and the use of main restoring springs at one side only of the spigot results in a relatively compact, yet still effective mechanism. The number of parts is kept as small as possible, whilst at the same time a positive horizontal hold of the handle in the rest position is achieved.

Claims

1. A door handle mechanism comprising a backplate, an operating member mounted on the backplate for angular movement relative thereto with an end part thereof received in the backplate, said end part having a member thereon, an element received in the backplate and extending on opposite sides of the operating member end part, biasing means at one side of the end part and acting between said member on the end part and part of said element at said one side of the end part, angular movement of the operating member causing said member on the end part directly or indirectly to move the element relative to the backplate, with said biasing means acting against said movement.

2. A door handle mechanism as claimed in claim 1, wherein said angular movement of the operating member causes said member on the end part directly or indirectly to act on part of said element at the other side of the end part to move the element relative to the backplate.

3. A door handle mechanism as claimed in claim 1 or claim 2, wherein said element is a generally flat plate having upturned ends, said end part of the operating member extending through an oversize aperture in said plate so that the plate can move in the backplate relative thereto, the biasing means acting between said member on the end part and one of the upturned ends of the plate, the other upturned end of the plate constituting said part of the element on which the member on the end part acts directly or indirectly to move said plate.

4. A door handle mechanism as claimed in claim 3, wherein said biasing means is at least one compression spring having one end against said one upturned end of the plate and its other end against a closed end of a chamber in a spring housing, against which the member on the end part engages.

5. A door handle mechanism as claimed in claim 4, wherein said member on the end part of the operating member is a cam member having a pair of diametrically opposed lobes, defining outer cam surfaces, with parallel diametrically opposed outer flat surfaces therebetween, a rest position of the operating member, in use, corresponding to one of said flat cam surfaces engaging an outer flat surface of said spring housing and the other of said flat cam surfaces directly or indirectly engaging said other upturned plate end, angular movement of the operating member from said rest position causing said one of the cam surfaces to move the spring housing in a direction to compress the or each spring, and the other of the cam surfaces directly or indirectly to slide the plate in the backplate so that said one upturned end of the plate also moves in a direction to compress the or each spring.

6. A door handle mechanism as claimed in claim 5, wherein the cam member acts indirectly on said other of the upturned plate ends, the cam member engaging a bearing element which itself bears on said other of the upturned ends.

7. A door handle mechanism as claimed in any one of claims 1 to 6, wherein a locking member is disposed in the backplate at said other side of the operating member end part, the locking member being manually movable from the exterior of the backplate to engage said member on said end part when the operating member is in a particular angular position, thereby releasably locking the operating member in said angular position.

8. A door handle mechanism as claimed in claim 7, wherein the locking member has at least one arm portion and the member on the end part has at least one surface engageable by a surface of the arm portion when the operating member is in said angular position, the arm portion being held between said member on the end part and a side wall of the backplate when its said surface engages said surface on said member on the end part.

9. A door handle mechanism as claimed in claim 8, wherein the locking member is a bifurcated plate having two arm portions engageable with respective diametrically opposed shoulders on the member on the end part when said operating member is in said angular position, each arm portion then being held between a shoulder and an adjacent side wall of the backplate.

10. A door handle mechanism as claimed in claim 9, wherein said part of the element at said other side of the end part is provided with slots at transversely spaced positions, said arm portions being received through said slots respectively, relative sliding movement between said part of the element and said arms occurring, in use, on angular movement of the operating member and also on movement of said locking member when said operating member is in said particular angular position.

11. A door handle mechanism as claimed in any one of claims 7 to 10, wherein biasing means is provided to act against movement of said locking member to engage said member on the end part, and to restore the locking member to a released position upon its disengagement from said member on the end part.

12. A door handle mechanism as claimed in claim 11, wherein said biasing means is a compression spring having its one end engaged on part of the locking member and its other end engaged with said part of the element at said other side of the end part.

13. A door handle mechanism as claimed in claim 11 or claim 12, wherein the strength of the spring acting to release the locking member is much weaker than the strength of the biasing means at said one side of the end part.

14. A door handle mechanism substantially as hereinbefore described with reference to and as shown in the accompanying drawings.