GB2095788A - Door handle spring return mechanism - Google Patents

Abstract

A spring-loaded mechanism for incorporation in a door handle operating assembly comprising an inner housing (10) mounted within an outer housing (11) for relative rotation of less than one revolution about an axis, cooperating parts (15, 16, 19 and 30) of the respective housings (10, 11) defining an arcuate recess centred on the axis of relative rotation and a compression spring (25) being located within the recess and extending between two detent members (22, 45) associated one with each of the respective housings (10, 11), the arcuate recess being symmetrical about a plane containing the axis and the detent member (45) associated with the outer housing (11), whereby the mechanism can be assembled for operation with the spring (25) extending around and within the recess in either direction between the two detent members (22, 45). The part of the outer housing (11) partially defining the recess and not containing the associated detent member (45) includes an arcuate groove (49) which receives at least part (23) of the detent member (22) associated with the inner housing (10), whereby a relative rotation between the inner and outer housings (10, 11) is limited to the angular extent of the arcuate groove (49). <IMAGE>

Description

SPECIFICATION Door handle mechanism This invention relates to spring-loaded mechanisms which return to an original position under spring action, when released, such as are used for returning a door handle to its original position after it has been actuated. The invention can be applied to any such mechanism, but for convenience is described in relation to a door handle.

Handle return mechanisms at present on the market had the disadvantage of being unduly large, bearing in mind their function and their association with equipment which is usually operated with a single hand. Because door handle return mechanisms are almost always accommodated within the handle structure, this added size limits their use and also restricts the design of door furniture from the aesthetic standpoint.

Known mechanisms also suffer from the limitation that they are permanently handed, so that ieft- and right-handed pairs of handles with the associated return mechanisms have to be used on each door. Many mechanisms also tend to seize when they are clamped on to the handle. A further problem can arise when the mechanism is solely made of plastics materials, because all such materials flex and such handles feel and look loose, therefore. In endeavouring to avoid this'last problem, some known constructions involve large areas of plastics materials in contact, which leads to the movement of the mechanism becoming sticky and jerky.

These disadvantages are avoided in the springloaded mechanism of this invention, which is suitable for incorporation in a door handle mechanism.

In accordance with the present invention, a spring-loaded mechanism comprises an inner housing mounted within an outer housing for relative rotation of less than one revolution about an axis, cooperating parts of the respective housings defining an arcuate recess centered on the axis of relative rotation and a compression spring being located within the recess and extending between two detent members associated one with each of the respective housings, the arcuate recess being symmetrical about a plane containing the axis and the detent member associated with the outer housing, whereby the mechanism can be assembled for operation with the spring extending around the recess in either direction from such detent member.

Preferably, the part of the outer housing forming the recess and not containing the associated detent member includes an arcuate groove which receives at least part of the detent member associated with the inner housing.

In order that the invention may be readily understood, a preferred embodiment of it is described below, by way of illustration, in conjunction with the accompanying drawings, in which: Fig. 1 shows diagrammatically an exploded perspective view, partly broken away, of the main components of the door handle mechanism of this invention; Figs. 2 and 3 show the inner housing and the spring in elevational view, assembled in the two alternative ways possible; Fig. 4 shows a perspective view of the inner parts of the outer housing, taken in the opposite direction from the fragmentary illustration of the outer housing in Fig. 1; Fig. 5 shows a cross-sectional view through the axis of the mechanism, taken as indicated by the arrows, V-V in Fig. 4.

The main components of the mechanism comprise an inner housing, shown at 10 in Figs. 1 and 5 and also in Figs. 2 and 3, an outer housing, shown at 11 in Figs. 1 and 5 and also in Fig. 4, a backplate, shown at 12 in Figs. 1 and 5, a compression spring 25 and a handle member 14, shown partly broken away in Figs. 1 and 5.

The inner housing 10 comprises a one-piece casting or moulding in the form of an annular flange 1 5 having a generally cylindrical wall 1 6 extending to one side from its edge 17 and a circular rib 18 of rectangular radial cross-section, as shown best in Fig. 5, extending to the other side and located a short distance in from the edge 17 of the flange 15. A further cylindrical wall 19 extends from the inner edge 20 of the flange 1 5 in the same direction as the wall 1 6 and to a greater axial distance and forms a large central boss for the inner housing 10.The hollow and cylindrical interior of the wall 1 9 includes a pair of opposed flat surfaces 21 which as explained in detail below cooperate with corresponding flat surfaces (not shown) formed upon the handle member 14 so that rotation of the latter is transmitted to the inner housing 10 and causes it to undergo rotation relative to the outer housing 11, as explained in more detail below.

The flange 1 5 and the walls 16 and 19 upstanding from its respective outer and inner edges 1 7 and 20 thus form a part-circular channel of approximately square internal radial crosssection. On a plane (not shown) passing through the axis of the inner housing 10 and at rightangles to the respective flat surfaces 21, the channel includes a detent member 22 which fills in and bridges across the space otherwise provided between the walls 16 and 19 and extends axially to the height of the outer wall 1 6.

The detent member 22 is extended further, adjacent the boss formed by the outer surface of the wall 19, in the form of a lug or projection 23 of approximately square radial cross-section which extends towards the periphery of the wall 19 and constitutes a second part of the detent member 22. A helical or coil compression spring 25 is bent into part of a circle, as shown in Fig. 1, and is lodged in the recess 26 formed by the channel formation of the inner housing, one end of the spring 25 being located against one or other side surface of the detent member 22. The two possibilities of so arranging the spring are shown respectively in Figs. 2 and 3.The inner housing 10 and also the other main components described in detail below, namely the outer housing 11, the backplate 12 and the handle 14, can be made of a wide variety of materials, ranging from diecast aluminium and zinc to thermosetting plastics and, more usefully and cheaply, thermoplastics such as polypropylene, high-density polyethylene, po lycarbonates, polya mides and, most preferably, acetal resins.

The outer housing 11 also consists of a onepiece casting or moulding comprising an annular flange 30 having an inwardly-radiused and outwardly-chamfered edge 31 merging with a cylindrical side wall 32. The flange 30 is essentially circular, having two opposed straight portions, one of which can be seen at 34 in Figs. 1 and 4. From an inner position on the flange and extending from it to the same side as the wall 32 extends an internal annular wall 35, the height of which is somewhat less than that of the side wall 32. This annular wall 35 is of such a size as to readily receive the external wall 19 of the inner housing 10. The flange 30 extends inwardly of the wall 35 to a thickened annular rib 36 defining a central aperture 37 and extending away from the flange 30 to the side opposite to the side wall 32 and the annular wall 35.Within the channel formation formed by the side wall 32, the annular wall 35 and the part of the flange 30 extending between them, four boss formations are formed in the one-piece outer housing 11. Two of these are located symmetrically with respect to the plane passing through the outer housing 11 parallel to the straight portions 34 of the side wall 32 and passing through the central axis. Each boss formation comprises a raised land area 38 adjacent an aperture in the annular wall 35 and each land area 38 is bounded on each side across the width of the channel formation by an opposed pair of arcuate walls 39 which extend to the same height from the flange 30 as the annular wall 35.

A central aperture 40 passes through the land area to a countersunk hole 41 in the flange 30.

Each land area is thus of partly-circular shape, the outer portion of the circle intersecting with the side wall 32, while the inner portion of each circular land area follows the curve of the annular wall 35.

At two spaced locations symmetrically at either side of the plane containing the boss formations just described, the other two boss formations are provided and each consists of a generally cr;;indrical block 42 extending between the side wall 32 and the annular wall 35 and rising from the flange 30 by the height of the wall 35. These two blocks 42 are located approximately where the straight portions 34 merge with the ends of one part of the side wall 32. Each block 42 includes a central aperture 43 which again merges with a countersunk hole 44 disposed in the outside of the flange 30, as shown for one of the faces 44 in Fig. 1.

On the inner part of the flange 30 inside the annular wall 35 and adjacent the boss formation constituting one of the land areas 38 with adjacent arcuate walls 39 and shown uppermost in Fig. 4, a generally trapezoidal detent member 45 is provided. This comprises an integral block the inner face 46 of which forms an inward extension of the aperture 37, while the opposed pair of side faces 47 are flat surfaces lying in planes which pass through the axis of the outer housing. The remaining outer face 48 of the detent member 45 is arcuate and is located adjacent the gap in the annular wall 35. In radial cross-section, the detent member 45 is so shaped that each of its side faces 27 substantially occupies the radial cross-section of the annular recess 26 formed in the inner housing 1 0.

Opposite the detent member 45 and occupying an arcuate extent around the inner part of the flange 30 symmetrical to the plane containing the detent member 45 and the axis of the outer housing 11, a groove 49 of approximately square radial cross-section is formed within the rib 36.

This groove 49, in the assembled mechanism receives the projection 23, indicated in broken lines in Fig. 4, forming part of the detent member 22 of the inner housing 10 and the arcuate extent of the groove 49 is such that the projection 23 can be located in the groove throughout a sweep of approximately half a revolution.

The back plate 12 also comprises a one-piece casting or moulding in the form of an annular flange 55 having a circular central aperture 36 and a part-circular outer edge, with two opposed straight portions 38, so that the back plate 12 fits into the outer housing 11 with the rib 18 on the inner housing within the aperture 56, the flange 55 extending to the periphery of the side wall 32 of the outer housing 11, the flange 55 of the back plate 12 resting against the annular area constituting the edge 1 7 of the flange 1 5 of the inner housing 10. On the inside surface of the flange 55 of the back plate 1 2, apertures are provided, as indicated at 57 and 58, which correspond respectively with the apertures 40 and the apertures 43 in the outer housing 11. Each of the apertures 57 formed in a part-cylindrical block 59 projecting from the flange 55 and terminating in a flat land area 60. Each block 59 is designed to fit within the recess defined between the arcuate walls 39, the adjacent part of the side wall 32 and the aperture within the annular wall 35 of the outer housing 11, so that the land area 60 of the block 59 is in face-to-face contact with the land area 38. A spaced pair of arcuate projections 61 is provided at either side of each block 59 and these are designed to fit within the channel formation in the outer housing on the outside of the respective arcuate wall 39. Similarly, a further pair of arcuate projections 62 is formed on either side of each aperture 58 and these fit on either side of the block 42 also provided inside the outer housing 11.

The component parts of the mechanism described above are assembled in the following manner. The spring 25 is located in the arcuate recess 26 in the inner housing 1 0, one end of the spring 25 being located against the side of the detent member 22 so that the other end of the spring leaves a space in the channel formation between itself and the other side of the detent member 22. The assembled spring and inner housing 10 are then fitted into the outer housing 11, so that the detent member 45 is aligned with this space. The wall 19 becomes located within the annular wail 35 of the outer housing 11 and the projection 23 forming part of the detent member 22 then contacts the flat surface of the rib 36. The inner and outer housings 10, 11 are then mutually rotated so that the spring 25 becomes compressed and the projection 23 comes opposite the groove 49.The two housing parts 10, 11 can then be fully fitted together, in the position shown in Fig. 5, so that the spring 25 extends arcuately between the detent members 22 and 45 and the inner housing 10 is rotatable through less than a revolution with respect to the outer housing 11 in such a way that this rotation compresses the spring 25, the projection 23 travelling along the groove 49. With the inner and outer housings 10, 11 assembled in this way, the back plate 1 2 is then fitted into the perimeter wall 32 of the outer housing 11. Hexagonal recesses (not shown) for receiving appropriate nuts are formed within the blocks 59 on the face of the backplate 12 which is fitted to the flat surface of a door furnished with the mechanism of the invention.Set screws with countersunk heads, not shown, can then be passed through the apertures 40 in the outer housing 11 so as to tighten the housing 11 to the backplate 12, so that the inner housing 10 is rotatably mounted within them. The apertures 43 enable the assembled mechanism to be secured for instance to a door by means of countersunk head screws which pass through these apertures 43 and the corresponding apertures 58 in the backplate 12.

The handle can be secured to a door, a star clip or circlip surrounding the boss 63 forming part of the handle 14 which fits between the opposed flat surfaces 21 in the inner housing 10 as mentioned above. The star clip or circlip 66 is indicated diagrammatically in Fig. 5. The boss 63 includes the usual square section axial aperture (not shown) which receives the standard square section bar 64 (Fig. 5) for transmitting the rotary action of the handle 14 to the rim lock or mortice lock fitted to the door. The handle can be used with any desired form of escutcheon, to which the mechanism itself is fitted, the escutcheon being the element attached to the door in this alternative case.

An advantage of the mechanism according to the invention is that there is a minimum of material in contact as between the various component parts, although the rotatable inner housing 10 is firmly held in the outer housing and the backplate 12. Movement of the inner housing 10 is smooth therefore and the handle 14 can be easily rotated but is firmly held at all times. If the unit has been assembled so as to be right-handed for instance, as shown in Fig. 1, and it is desired to assemble it for use with an oppositely handed door, it is a simple matter to detach the mechanism from the door, separate its component parts and re-assemble so that the spring 25 is arranged with its other end against the detent 22 and so that contrary rotation of the handle is then provided. The handle can be turned approximately through 900 in whichever form of assembly is used and when released it returns smoothly under the relatively powerful action of the long and large compression spring 25 to its original position.

Claims (1)

1. A spring-loaded mechanism for incorporation in a door handle operating assembly, comprising an inner housing mounted within an outer housing for relative rotation of less than one revolution about an axis, cooperating parts of the respective housings defining an arcuate recess centred on the axis of relative rotation and a compression spring being located within the recess and extending between two detent members associated one with each of the respective housings, the arcuate recess being symmetrical about a plane containing the axis and the detent member associated with the outer housing, whereby the mechanism can be assembled for operation with the spring extending around and within the recess in either direction between the two detent members.

2. A mechanism according to claim 1, wherein: (a) the inner housing comprises an annular flange having a first, generally cylindrical wall extending axially from the outer edge thereof and a second, generally cylindrical wall extending axially from the inner edge thereof in the same direction as, but to a greater axial extent than, the first cylindrical wall, with the flange and first and second cylindrical walls defining a part-circular channel and, (b) the outer housing comprises an annular flange portion having an annular wall extending axially from the periphery thereof in the direction opposite to that which the first and second cylindrical walls of the inner housing extend, the outer surface of the first cylindrical wall of the inner housing being located in confronting relationship with respect to the inner surface of the annular wall of the outer housing, whereby the annular flange and first and second cylindrical walls of the inner housing and the annular flange portion of the outer housing define the arcuate recess centred on the axis of relative rotation.

3. A mechanism according to claim 2, wherein the detent member associated with the inner housing extends between the first and second cylindrical walls thereof.

4. A mechanism according to claim 1,2 or 3, wherein the part of the outer housing or the annular flange portion thereof as the case may be, partially defining the recess and not containing the associated detent member, includes an arcuate groove which receives at least part of the detent member associated with the inner housing, whereby relative rotation between the inner and outer housings is limited to the angular extent of the arcuate groove.

5. A mechanism according to claim 4, when dependent upon claim 2 or 3, wherein the part of the detent member associated with the inner housing received in the arcuate groove in the outer housing is located on the outer surface of the second cylindrical wall of the inner housing and extends to a greater axial extent than the remaining part thereof.

6. A mechanism according to any preceding claim including a backplate cooperating with the inner and outer housings, to retain the inner housing within the outer housing.

7. A mechanism according to claim 6, wherein the outer housing and back plate are fixed with respect to each other and the inner housing is relatively rotatable with respect thereto.

8. A mechanism according to claim 6 or 7, wherein the outer housing and backplate have respective cooperating means to enable the mechanism to be secured to a support.

9. A mechanism according to any preceding claim, wherein the inner housing has a pair of opposed flat surfaces for cooperating with corresponding flat surfaces of an operating handle, so that rotation of the latter can be transmitted to the inner housing to cause it to undergo relative rotation with respect to the outer housing.

10. A mechanism according to any preceding claim whose component parts, except the compression spring, are moulded from a plastics material.

12. A mechanism according to any preceding claim including an operating handle.

13. A spring-loaded mechanism for a door handle operating assembly substantially as hereinbefore described with reference to the accompanying drawings.

14. A door handle operating assembly incorporating a mechanism according to any preceding claim.

1 5. A door when fitted with an assembly according to claim 14.