GB2304789A - Return spring mechanism for door handle - Google Patents

Abstract

A door handle (152) is pivotably mounted for rotation within a backing plate (154) between a horizontal door latching disposition and an inclined unlatching or door release disposition. A return spring mechanism urges the door handle (152) towards and into the horizontal door latching disposition from the inclined unlatching or door release disposition. The return spring mechanism has two coil springs (176, 177), each of which is compressively engaged between a fixed first abutment (178, 179) and a movable second abutment (174, 175). Each second abutment (178, 179) is provided on a washer (162) which is rotatable with the handle (152). Each first abutment (174, 175) is defined by an apex where two spring-accommodating channels or grooves (170, 171) formed in the backplate (154) meet. The abutment apices (174, 175) are fixed relative to the direction of rotation of the handle (152). Each channel (170, 171) has a first linear or straight portion (172, 173) extending from the apex (174, 175) and is continued by a part-circular portion within which said second abutment (178, 179) is arcuately displaceable. The greater part of spring (176, 177) movement thus takes place within the straight portion (172, 173), thereby reducing wall friction between channel and spring, providing improved efficiency of operation of the return spring mechanism, and enhancing spring life. The invention also encompasses a single spring variant.

Description

"DOOR LEVER HANDLES" This invention relates to lever handles for doors, in particular internal doors in a domestic house or other like premises. The invention is particularly directed to an improvement in spring mechanisms for biassing the lever of a door handle towards a latching position.

A multiplicity of designs of return springing mechanism for door handles are known, including inter alia those described in British Patent Specifications Nos. 1,496,934 and 2,227,518A. In the arrangement described in GB 1,496,934, a pair of springs are housed in respective semicircular recesses in the backing plate for the door handle mechanism and act against a rotatable member secured to the lever handle in such a manner as to tend to restore the handle towards a horizontal latched disposition, whenever the handle lever is displaced towards a rotated latch release disposition.

GB-A-2,227,518 describes a biassing unit and backplate assembly in which the biassing unit is of cartridge form. A backplate is secured to the face of a door and a flanged nylon retaining bush in turn secures a nylon carrier for the biassing unit to the backplate. In the arrangement described, the biassing unit is snap-fitted to the nylon carrier by a pair of flexible arms. The retaining bush is also provided with a number of flexible fingers at its end remote from the flange for snap-fitting engagement in a hole in a base region of the carrier, a projection of the carrier in turn being received in a hole of the backplate.Surfaces of the flexible fingers of the retaining bush engage an annular shoulder between the hole in the base region of the carrier and a further hole in the projection of the carrier so that the flange of the retaining bush is held tightly against one side of the backplate and the carrier, with the biassing unit, is held similarly tightly against the other side of the backplate.

A disadvantage of a spring arrangement of the kind described in GB 1,496,934, in which the springs are continuously curved when mounted in the backing plate of the handle mechanism, is that there is frictional action between the outer periphery of each curved spring and the recess within which it is housed or accommodated. This friction may lead to extensive and excessive wear on the outside of the spring, especially where a steel spring is accommodated in a die casting formed from for example zinc, such an arrangement being prone to adverse metal to metal interaction. Furthermore, the continuous curve of the spring provides it with an inherent bias towards buckling.These various factors combine to reduce spring life, so that the satisfactory service life in use of such a door handle arrangement subjected to a typical average number of operations is generally of the order of some nine to ten years only. While the friction and metal to metal action may be alleviated or relieved or reduced to some degree by the introduction of a nylon bush to sheath the spring or otherwise to take up a location between the spring and the recess of the housing or backing plate, such measures result in the introduction of an extra component and thereby add to the cost of the unit.

The solution adopted in GB-A-2,227,518 provides a structure in which the spring action is straight line. In this arrangement, there is no curvature of the spring at any stage, so that the problems set out above are substantially eliminated. However, this satisfactory result is achieved at the cost of additional components being present in the structure, so that there is additional complexity in assembly as well as extra cost incurred in providing these additional parts. A further potential disadvantage of such a structure is that a custom-made spring may be required, thereby adding to the cost involved and leading also to difficulties in sourcing and maintaining a suitable stock of this component.

It is an object of the present invention to provide an improved return spring mechanism for a door lever handle in which at least some of the foregoing disadvantages are overcome or alleviated. It is a further object of the invention to provide such an improved spring mechanism with a minimum of component parts.

According therefore to the invention, there is provided a return spring mechanism for urging a door handle towards and into a door latching disposition from an unlatching or door release disposition, the door handle being pivotably mountable for rotation between said door latching disposition and said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment and a second abutment, the second abutment being rotatable with the handle and the first abutment being fixed relative to the direction of rotation of the handle, wherein said at least one coil spring is accommodated in a channel which has a first linear or straight portion extending from said first fixed abutment and is continued by a part-circular portion within which said second abutment is arcuately displaceable.

In a favoured embodiment of the return spring mechanism of the invention, there are two said channels, each channel extending from a respective first fixed abutment, said fixed abutments being disposed on diametrically opposite sides of the axis of rotation of the handle, and each channel being continued by a further linear or straight portion extending from said part-circular portion towards and to the first fixed abutment from which the other channel extends, so that the first linear or straight portion of each channel meets the further linear or straight portion of the other channel at an apex and the two apices thus defined are disposed on diametrically opposite sides of the axis of rotation of the handle, each apex itself also defining a first fixed abutment for one of said channels. The mechanism suitably has two coil springs, one accommodated in each said channel.

In an alternative embodiment, the mechanism may have two said channels, each channel extending from said first fixed abutment, and the part-circular portions of each channel being continued to meet one another at a location on the opposite side of the axis of rotation of the handle from said fixed abutment, so that the first linear or straight portions of the two channels meet one another at an apex, said apex also defining said first fixed abutment, and the part-circular portions of the channels define an arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment. A single coil spring is suitably accommodated in one of said channels, and a stop portion is provided at a location on said arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment which is substantially diametrically opposite said apex, for cooperation with a stop portion which is rotatable with the handle to limit maximum rotation of the handle towards said unlatching or door release disposition.

In any embodiment of return spring mechanism of the invention, the or each feature which is rotatable with the handle is preferably provided on a member which is rotatably associatable with the handle.

Said member which is rotatably associatable with the handle may have at least one stop region on a peripheral surface region thereof radially outward of its axis of rotation to limit maximum rotation of the handle towards at least one of said door latching disposition and said unlatching or door release disposition by engagement of said at least one stop region against a cooperating fixed stop portion of the mechanism. Said member which is rotatably associatable with the handle is suitably mountable on a shank or shaft portion of the handle for rotation therewith, said shank or shaft portion being bearingly receivable in a backing plate for association with the handle in a handle assembly.

In a favoured embodiment, the or each said channel and fixed abutment are formed integrally in said backing plate. Alternatively, said member which is rotatably associatable with the handle may be accommodated within a cassette housing, optionally in the form of a cam follower, a shank or shaft portion of the handle being insertable through said cassette housing and rotatable member, and the cassette housing being fixedly associatable with a door in an assembled condition of the handle and return spring mechanism. The or each said channel and fixed abutment are then comprised in said cassette housing.

According to the invention in a further aspect, there is provided a door handle assembly having a handle pivotably mounted in a backing plate for rotation between a door latching disposition and an unlatching or door release disposition, and a return spring mechanism for urging the handle towards and into said door latching disposition from said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment which is fixed relative to the backing plate and a second abutment which is rotatable with the handle, wherein said at least one coil spring is accommodated in a channel which has a first linear or straight portion extending from said first fixed abutment and is continued by a part-circular portion within which said second abutment is arcuately displaceable.

In a favoured embodiment of the door handle assembly of the invention in this aspect, there are two said channels, each channel extending from a respective first fixed abutment, said fixed abutments being disposed on diametrically opposite sides of the axis of rotation of the handle, and each channel being continued by a further linear or straight portion extending from said part-circular portion towards and to the first fixed abutment from which the other channel extends, so that the first linear or straight portion of each channel meets the further linear or straight portion of the other channel at an apex and the two apices thus defined are disposed on diametrically opposite sides of the axis of rotation of the handle, each-apexitselfa-lso defining a first fixed abutment for one of said channels.The assembly suitably has two coil springs, one accommodated in each said channel.

In an alternative embodiment, the assembly may have two said channels, each channel extending from said first fixed abutment, and the part-circular portions of each channel being continued to meet one another at a location on the opposite side of the axis of rotation of the handle from said fixed abutment, so that the first linear or straight portions of the two channels meet one another at an apex, said apex also defining said first fixed abutment, and the part-circular portions of the channels define an arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment.A single coil spring is suitably accommodated in one of said channels, and a stop portion is provided at a location on said arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment which is substantially diametrically opposite said apex, for cooperation with a stop portion which is rotatable with the handle to limit maximum rotation of the handle towards said unlatching or door release disposition.

In any embodiment of this aspect of the invention, the or each feature which is rotatable with the handle is preferably provided on a stop washer which is rotatably associated with the handle. Said stop washer is suitably fixedly mounted on a shank or shaft portion of the handle for rotation therewith, said shank or shaft portion being bearingly received in the backing plate and said stop washer also cooperating with a circlip or like feature to retain said shank or shaft portion against axial withdrawal from said backing plate.

In a favoured embodiment, the or each said channel and fixed abutment are formed integrally in said backing plate, which is suitably a die casting, along with any further fixed or non-rotatable features.

Alternatively, the or each said channel and fixed abutment may be comprised in a cassette structure for association with a backing plate as already previously indicated.

In a further aspect, the invention thus also provides a door handle assembly having a handle pivotably mounted relative to a backing plate for rotation between a door latching disposition and an unlatching or door release disposition, and a return spring mechanism accommodated within a cassette housing fixedly associated with said backing plate for urging the handle towards and into said door latching disposition from said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment which is fixed relative to the backing plate and a second abutment provided on a member which is rotatable with the handle, wherein said at least one coil spring is accommodated in a channel provided within said cassette housing which has a first linear or straight portion extending from said first fixed abutment and is continued by a part-circular portion within which said second abutment is arcuately displaceable.

Embodiments of the invention will now be described having regard to the accompanying drawings, in which: Figure 1 is an exploded view of a dual spring arrangement according to the present invention, Figure 2 shows the side of the stop washer which is directed towards the springs in the assembled condition of the unit of the invention, Figure 3 is a partially schematic diagram showing the disposition of the device in the rest or latched position of the handle, Figure 4 is a drawing similar to Figure 3 showing the condition of the device in the pivoted or unlatching condition of the handle, and the manner in which the springs are-stressed un-der-thee-~~condit-ions, Figure 5 is an exploded view of a right-hand single spring arrangement of the device according to the invention, Figure 6 shows the side of the backing washer of the arrangement of Figure 5 which is directed towards the spring in the assembled condition of the unit of Figure 5, Figure 7 is similar to Figure 3, showing the rest condition of the door handle unit for the single spring arrangement of Figure 5, Figure 8 shows the unlatched or pivoted condition of the handle for the single spring unit of Figure 5, Figures 9 and 10 correspond to Figures 3 and 4 for a left-hand handle assembly, compared with the right-hand arrangements of Figures 1 to 8, Figure 11 shows a cassette embodiment of the invention with double springing, Figure 12 shows a further backplate embodiment of a dual spring arrangement according to the present invention, and Figure 13 shows a further embodiment of a single spring backplate arrangement of a device in accordance with the invention.

As shown in Figure 1, a door lever handle with a springing mechanism according to the invention has a lever type handle 2 and a backing plate 4. The backing plate 4 is secured to or mounted on the external surface of a door fitted with a latching mechanism which is to be operated by the handle 2. To this endr the handle 2 has a shaft or shank or spindle portion extending at right-angles to the gripping part of the handle, this shaft portion defining a fixing end 9 of the handle 2.The handle 2 is received in a location hole 6 in the backing plate 4 and a nylon bush 8 placed on the fixing end 9 of the handle 2 acts as a bearing for the handle 2 in the locating hole 6.- Thefixing-end 9 of the handle 2 has a pair of opposed flats 10, and the handle 2, when its fixing end 9 is pushed through the location hole 6, is retained within the backing plate 4 by a retaining stop washer 12. Washer 12 has a central aperture 13 matching the profile of the flats 10 at the fixing end 9 of the handle 2. Washer 12 is pushed onto the fixing end 9 so that the opposed straight portions of the periphery of aperture 13 engage over the flats 10 of the fixing end. Washer 12, when mounted on the fixing end 9 of the handle 2, then rotates with the handle 2 when the handle is pivoted.Washer 12 is held in position on the fixing end 9 of the handle 2 against axial displacement or removal from the handle by means of a retaining spring type circlip 14, which is snapped into position in a circumferential groove 16 at the fixing end 9 of the handle 2.

A spring housing is formed by two part circular channels or recesses or grooves 20, 21 formed in the backing plate 4 on its inner side which is directed towards the door in the mounted condition of the device, the channels 20, 21 extending around the periphery of the handle location hole 6 radially outwardly of the hole 6. Backing plate 4 is most suitably a die cast product formed from a zinc alloy and the channels 20, 21 and other features of the structure are most suitably formed by moulding the metal material during the casting operation. Nonetheless, the spring mounting features of the backing plate may also be provided in any other suitable manner, and an independent spring mounting structure or cassette for association with a handle may also be provided, as subsequently described.As shown however in Figure 1, each of the spring accommodating channels 20, 21 defines substantially a quarter circle around the sides of the handle location hole 6 close to the sides 5 of the backing plate 4, one quarter circle to each side of the hole 6. Above and below the location hole 6, the channels 20, 21 become straight and the upper and lower straight portions 22, 23 of the channels 20, 21 meet at respective apices 24, 25 above and below the locating hole 6.

The structure is completed by a pair of spring-s-26-,7;-shw-fl-i their mounted configuration in the exploded view of Figure 1. It will be appreciated that in a relaxed pre-mounting disposition, the springs 26, 27 are in fact of generally cylindrical form, and that the partially curved profile shown in the drawings is taken up by the springs only following insertion into the channels 20, 21.When in position in the respective channels 20, 21, one end of each spring 26, 27 engages a respective apex 24, 25, while the other end of the spring 26, 27 is engaged by a respective abutment portion 28, 29 of the retaining stop washer 12, this abutment feature being further shown in Figure 2, which shows the other side of the washer 12 from that apparent in Figure 1, namely the inner side which is directed towards the spring channels 20, 21 in the assembled condition of the device and which carries the abutment portions 28, 29. Two abutment portions 28, 29 are provided, so that the right-hand spring 26 as shown in Figure 1 extends in the mounted condition between the upper apex 24 and the abutment portion 28 which is most distant from that apex, i.e. the lower abutment as shown in the drawings.Each abutment portion 28, 29 extends into a respective channel 20, 21 to form an end stop against expansion of the spring 26 or 27 accommodated in that channel beyond that abutment and to maintain a compressive force on the spring 26 or 27 between abutment 28 or 29 and the respective apex 24 or 25. The other or left-hand spring 27 extends between the other or lower apex 25 and the second abutment portion 29, which is again that portion most remote from the particular apex in the assembled condition of the structure and being the upper abutment of the washer 12 as shown in the drawings.Thus one spring 26 extends from the upper apex 24 towards the lower abutment 28 of the stop washer 12, while the other spring 27 extends from the lower apex 25 to the upper abutment 29, as it appears in the drawings, one spring 26 being located to one side of the location hole 6, namely its right-hand side in Figure 1, and the other spring 27 located to its other or left-hand side.

The manner of assembly of the arrangement of the invention is as follows: The handle 2 is fitted to the plate 4 following placement of the nylon bush 8 on the fixing end 9 of the handle 2. The handle fixing end 9, with nylon bush 8, is then pushed through the location hole 6 in the plate 4. The retaining stop washer 12 is pushed onto the flats 10 on the fixing end 9 of the handle 2, and the retaining spring type circlip 14 is fitted into the groove 16 in the fixing end 9 of the handle 2. The handle 2 is thus pivotably held on the plate 4 to form a single assembly.

The upper or right-hand coil compression spring 26 as it appears in Figure 1 is then inserted into the first channel 20 at the upper apex 24, which is accessible by virtue of the set-back portion 32 of the upper periphery of the washer 12 in the handle horizontal disposition of the pre-assembled handle 2 and plate 4. Spring 26 is pushed into the upper straight channel portion 22 until the lower end of the spring 26 abuts against the lower abutment portion 28 of the retaining stop washer 12 in the handle horizontal disposition of the device. This lower abutment portion 28 is located at the transition from the part-circular portion of channel 20 to the lower straight section 23 leading to lower apex 25 in this handle horizontal condition of the device. Abutment portion 28 extends from the inner surface of washer 12 into the channel or groove 20 so as to exert a compressive force against the lower end of spring 26 in the assembled condition of the device. The upper end of the spring 26 is then forced into the channel 20 to be retained by the compressive action of the stressed spring 26 against the side wall of the channel 21 where it meets channel 20 at apex 24. The spring insertion action is straightforward and is terminated by the spring 26 snapping into place in apex 24 under its own compressive action as exerted between the lower abutment portion 28 of the washer 12 and the channel side wall portion at apex 24. The second spring 27 is inserted in similar manner from the opposite or lower apex 25.Spring 27 is similarly easily insertable into channel 21 from the lower end as applies to the insertion of spring 26 into channel 20, by virtue of access to the apex 25 being unobstructed, due to the curved periphery of the stop wa-ser-ii i-n-this region. This spring 27 is thus pushed into the channel 21 from lower apex 25 until its lower end can be snapped down to abut against the planar end surface of the channel at the apex 25, spring 27 then being held in place under its own compressive force between upper abutment 29 and the channel side wall at the lower apex 25.

The assembly is capable of being rotated through an angle up to 700 away from the horizontal against spring action. It is then returned to the horizontal by virtue of the springs 26, 27 acting against the abutments 28, 29 of the retaining washer 12. The dual spring arrangement provides an especially effective and balanced return force.External side stops 30 and 31 on the stop washer 12 limit the degree of rotational travel of the handle assembly to the required 0 Referring 70 . refereing again to Figures 1 and 2, the external side stop 30 is provided on the right-hand side of the stop washer 12, in the view of Figure 1, and defines a nose portion of the washer structure which is positioned and dimensioned so as to engage the inner surface of the right-hand side wall 5 of the backing plate 4, as seen in Figure 1, when the handle is in a horizontal disposition, thus preventing further rotation of the lever handle 2 beyond the horizontal latching disposition into an orientation in which the handle 2 would be inclined upwardly away from its pivot axis relative to the horizontal.The second rotation abutment or side stop 31 is formed by a further nose portion of the washer 12, in this case on an upper left-hand region of the washer as it appears in Figure 1, and this stop portion is arranged to engage the inner surface of the opposite or left-hand side wall 5 of backing plate 4 when the handle 2 is rotated fully into an unlatched or door opening disposition. Stop 31 is thus positioned to limit the rotational travel of the handle 2 in a direction downwardly away from the horizontal.

Referring now to Figures 3 and 4, these show respectively the handle assembly of Figures 1 and 2 in a handle horizontal or closed or latching disposition and in the handle pivoted or rotated orientation of the unit, this being an unlatching or door opening disposition. As shown in Figure 3, the springs 26 and 27 are expanded to their maximum possible extent between the respective abutment portions 28 and 29 and the respective apices 24 and 25 of the channels 20 and 21 within which the springs are accommodated.The springs are arranged to urge the stop washer 12, and thereby the handle 2 fixedly connected to the stop washer for rotation therewith, in a clockwise direction, as shown in this drawing, and this clockwise bias is limited as to the possible rotational displacement of the handle 2 by engagement of the washer nose or abutment 30 against the inner surface of the side wall 5 on the right-hand side of the backing plate 4.

Figure 4 shows the situation when the handle 2 is grasped by a user and rotated downwardly away from the horizontal. Since washer 12 is fixedly secured to the fixing end 9 of handle 2, the washer 12 is in turn rotated. The abutment portions 28 and 29 are therefore rotationally displaced about the axis of pivoting of the handle 2 and washer 12 so as to compress further the springs 26 and 27, compressively retained between abutments 28 and 29 and apices 24 and 25 respectively. The handle may continue to be rotated until such time as the second rotation or pivot abutment 31 of the washer 12 engages against the inside surface of the left-hand side wall 5 of the backing plate 4, this terminating the counterclockwise door-opening rotation of the handle 2.On release of the handle 2 by the user or a relaxation of the door opening action, the increased compression of the springs 26 and 27 acts immediately to exert a clockwise return force to restore the handle 2 to the initial handle horizontal disposition. Thus the action of the springs 26, 27 is always to exert a clockwise force to bring the handle 2 to the handle horizontal disposition, and this spring action is overcome by a user exerting a counterclockwise force, in the view of Figures 3 and 4, to overcome the spring force and enable the door on which the handle 2 is mounted to be unlatched and opened.

A particular advantage of the spring arrangement of the present invention is that the location channels 20, 21 for the springs are in part straight, and only a portion of each spring mounting channel is curved. Thus when the springs 26, 27 are in position in the channels 20, 21 and engaged and retained therein by the fixing washer 12 attached to the lever handle 2 for rotation therewith, and the spring compression is increased by an opening movement of the handle lever 2, only a portion of the spring compression takes place by rotating compressive action within the circular channel portion, and the major part of the spring compression takes place in the straight channel portions 22, 23.There is thus a reduction in channel wall to spring friction as compared with fully circularly-accommodated springs, so that the torque which may be exerted by the spring is increased and there is an improved efficiency of action. Furthermore, the reduction in friction and wear enables the working life of the spring and handle assembly to be greatly extended, by up to a factor of 3.

The dual spring arrangement shown in Figures 1 to 4 is especially advantageous in providing for fully balanced forces within the handle assembly and represents a favoured and preferred embodiment of the invention. However, satisfactory operation may also be achieved by a single spring arrangement. A single spring arrangement may be provided simply by omitting one of the two springs from the dual spring structure of Figures 1 to 4. However, a lever handle assembly specifically adapted to the use of a single spring may also be provided, in which advantage is taken of the absence of a second spring to put in place an alternative rotational stop feature. Such an embodiment is shown in Figures 5 to 8, which Figures correspond in their various views to those of Figures 1 to 4. These drawings use similar reference numbers to those of Figures 1 to 4, with the addition of 50 in each case.As compared with the first embodiment, there is however only one spring 76 provided, and a single spring abutment portion 78. In addition, the backing plate 54, while provided with two channels 70 and 71, has only a single upper apex 74 and upper straight channel portions 72 leading to this upper apex 74.

At the lower end of the channels 70, 71, there is no second apex, and the part-circular side portions of the channels 70, 71 continue in a circular manner to fully surround the lower periphery of the locating hole 56. Where the two channels 70 and 71 meet below the locating hole 56, there is provided an integral abutment 83 located at the meeting point of the channels 70 and 71. The stop washer 62 is provided with a cooperating abutment 84, which in the assembled condition of the device extends into and is located in the channel 71, i.e. the channel which does not accommodate the spring. Cooperation between channel abutment 83 and washer abutment 84 provides an alternative manner of limiting the rotational displacement of the handle 52 relative to the backing plate 54.The provision of channel abutment 83 may however be omitted, as also may be the washer abutment 84, and a continuous unobstructed channel arrangement 70, 71 formed.

In this circumstance, handle rotation may be limited or constrained in the manner already described for Figures 1 to 4, by means of camming or abutting surfaces on the stop washer 62 engaging the inner side walls 55 of backing plate 54.

The present variant of the invention is further illustrated in Figures 7 and 8, which are comparable to Figures 3 and 4, and show this embodiment of the invention in the handle horizontal and handle rotated dispositions respectively. The action of spring 76 between upper apex 74 and lower abutment 78 is identical in its biassing and restoring or return action as already described for the dual spring arrangement of Figures 1 to 4. The handle horizontal position may again be maintained by rotation abutment 80 engaging the inner surface of right-hand side wall 55 of backing plate 54. Alternatively however, the handle horizontal disposition may be maintained by abutment against the channel abutment 83 of the opposite face of portion 78 from that engaging the lower end of spring 76, as can be seen in Figure 7.The limit in this embodiment on maximum handle rotation is also achieved by channel abutment 83, in this case by engagement of washer abutment 84 against the opposite face of channel abutment 83 from that engaged by abutment 78 in the handle horizontal disposition. Figure 8 shows the handle assembly in a part rotated condition, with washer abutment 84 approaching channel abutment towards~~th-e-~tem rina-tio-n-of-handle ~-~- rotation.

The action of this variant of the invention is identical with the dual spring arrangement, save only that the restoring force is exerted by a single spring rather than by two springs.

Figures 1 to 8 have shown the invention in a right-hand embodiment. The invention is readily adaptable to a left-hand type assembly, where the position of the handle is reversed compared with the arrangement shown in Figures 1 or 5, to extend in the opposite direction relative to the backing plate. In the dual spring arrangement, a mirror image washer is provided, but all other features remain exactly the same, the springs merely being reversed so that the upwardly extending spring, relative to the lower apex, is then on the right-hand side and the downwardly extending spring from the upper apex is on the left-hand side of the assembled structure, in its Figure 1 orientation. Figures 9 and 10 correspond to Figures 3 and 4 for this reversed or left-hand arrangement.The reference numerals for the features of Figures 9 and 10 correspond to those of Figures 3 and 4, with the addition of the suffix "L".

Precisely the same applies to the single spring structure of Figures 5 to 8. Again a mirror image washer is required, but all other components are identical. The spring is merely inserted into the left-hand channel 71 rather than the right-hand channel 70.

The embodiments described provide for the formation of the spring accommodating channels within the actual backing plate structure, such as is particularly conveniently effected in a die cast unit. The spring mechanism of the invention may however also be embodied or incorporated in a so-called cassette type arrangement, in which the spring accommodating features are provided in a separate component which is associated with the handle at the time of assembly of the handle unit, such as by way of a backplate.

Figure 11 shows a particular cassette0r-cartridge-enboiment of the return spring mechanism of the invention. The cassette has a plastics or zinc housing 104 having side walls 105 and a central circular cam follower locating hole 106. Two channels or spring grooves 120, 121 are formed around this hole. These channels straighten at each end and terminate at respective top and bottom apices 124 and 125 by way of respective upper 122 and lower 123 straight portions, the intersections of these straight portions 122, 123, forming the respective apex 124 or 125. Two retaining or mounting spigots 107 allow the attachment and securing of a cover plate 115. Alternatively, features 107 may define two bosses having threaded holes for screw mounting of the cover plate 115, in the assembled condition of the unit.

Compression springs 126, 127 are loaded into the opposite channels 120, 121, in the manner previously described for the handle and backplate assembly of Figure 1. The springs 126, 127 butt up against an end vertical wall of the respective apex 124 or 125 and also butt against respective portions 128, 129 of a cam follower 112 which is rotatably mounted in the location hole 106 of the cassette housing 104 by means of a suitable boss or spigot portion of substantially circular cross-section. The assembly thus resembles that already described for the handle/backplate arrangement of Figure 1. The cassette is closed by the cover plate 115 being located on the spigots 107, which may then be welded, or alternatively, the cover plate 115 is secured by screwing to threaded apertures in bosses 107.A further spigot portion 117 of the cam follower 112 passes through and rotates within a cooperating locating aperture 118 in cover plate 115.

The cassette assembly is fitted to a plate and handle structure at the point of attachment to a door and lock. A substantially square section spindle bar is passed through the lock, then through the square section aperture 113 of the cam follower and further into a cooperating square cross-section hole provided in the handle. The second handle is similarly mounted on the opposite side. When the lever handle is operated by turning, the spindle bar rotates the cam follower 112 within the cassette structure, thereby compressing both springs by a pressing force exerted by the abutment portions 128, 129 of the cam follower 112. The springs 126, 127 are thus compressed and straighten out within the straight portions 122, 123 adjacent to the apices 124, 125. This arrangement generates a maximum torque, while yet reducing and substantially minimising wear resistance.These advantages flow from the present design, in the manner already previously described.

On release of the handle, which in the arrangement shown is a lefthand structure, the cam follower 112 returns to its original initial position and the springs 126, 127 follow the contour of the channels 120, 121 to maintain torque on the cam follower 112, which is in turn transferred to the handle, to restore the handle to the horizontal position. The cassette variant of the invention is thus mounted on a door handle and door assembly in known manner, while yet providing the advantages previously recited for the Figure 1 handle and backplate integral construction of the invention, in either lefthand or righthand configurations.

Rotational limitation of turning of the handle may be effected by an end stop arrangement defined by a lug 135 which projects radially from the periphery of spigot portion 117 for orbital movement within a recess 136 in the inner wall or circumference of aperture 118. In its end position, lug 135 abuts one or other of the end faces 137, 138 of recess 136, these corresponding to the normal (handle horizontal) and rotated dispositions of the handle. Alternatively other stop arrangements may be provided, as already identified for the handle and backplate assembly of Figure 1. A single spring cassette embodiment may also be provided. To facilitate assembly, the cam follower 112 may be a symmetrical component, so that it may be mounted in either of two dispositions and does not have a normal and inverted orientation.A symmetrical placement of the stops 128, 129 also facilitates use of the cassette for left-handed or right-handed assemblies, in a substantially uniform manner, without its being necessary to retain a separate inventory of left-handed and right-handed component parts.

Figures 12 and 13 show further embodiments of the invention in a dual spring arrangement, Figure 12, and a single spring arrangement, Figure 13. The arrangements shown correspond broadly to those of Figures 1 and 5 respectively, and the reference numerals are the same as those for Figures 1 and 5, but in the number sequence 151 to 199, thus with the addition of 150 or 100 respectively, as compared with the reference numerals applicable to Figures 1 and 5. The principal difference from the earlier Figures now requiring mention is the use of an alternative profile of stop washer 162, which can be of generally symmetrical configuration, and thus usable irrespective of the hand of the lever assembly, whether lefthand or righthand, and also whether two springs are in use, or one spring.The external profile of this modified embodiment of stop washer 162 is such that a lateral or side rotation abutment 180 is provided, corresponding to abutments 30 or 80 of Figures 1 and 5 respectively, while a second upper or top rotation abutment 181 carries out the function fulfilled by abutment 31 in the embodiment of Figure 1. Component standardisation thus facilitates the production of a diversity of constructions of the invention with a minimum of parts.

Symmetrical placement of the abutment portions 178, 179 substantially centrally between the top and bottom of the washer 162 in the side edge regions of the plate-shaped washer radially outward of the profiled aperture 163 for reception of the washer on the handle flats 160, also facilitates use of this embodiment of the invention for left-handed or right-handed assemblies, in a substantially uniform manner, without its being necessary to retain a separate inventory of left-handed and right-handed component parts, in that a fully invertible component may be provided, usable for either left- or right-handed arrangements irrespective of its orientation, i.e. which end is uppermost, or alternatively, the arrangement may be such that the washer applies to left-hand handles when a particular end is uppermost and to right-hand assemblies when that end is directed downwards.

Claims (15)

1. A return spring mechanism for urging a door handle towards and into a door latching disposition from an unlatching or door release disposition, the door handle being pivotably mountable for rotation between said door latching disposition and said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment and a second abutment, the second abutment being rotatable with the handle and the first abutment being fixed relative to the direction of rotation of the handle, wherein said at least one coil spring is accommodated in a channel which has a first linear or straight portion extending from said first fixed abutment and is continued by a part-circular portion within which said second abutment is arcuately displaceable.

2. A return spring mechanism according to Claim 1, having two said channels, each channel extending from a respective first fixed abutment, said fixed abutments being disposed on diametrically opposite sides of the axis of rotation of the handle, and each channel being continued by a further linear or straight portion extending from said part-circular portion towards and to the first fixed abutment from which the other channel extends, so that the first linear or straight portion of each channel meets the further linear or straight portion of the other channel at an apex and the two apices thus defined are disposed on diametrically opposite sides of the axis of rotation of the handle, each apex itself also defining a first fixed abutment for one of said channels.

3. A return spring mechanism according to Claim 1 or Claim 2, having two coil springs, one accommodated in each said channel.

4. A return spring mechanism according to Claim 1, having two said channels, each channel extending from said first fixed abutment, and the part-circular portions of each channel being continued to meet one another at a location on the opposite side of the axis of rotation of the handle from said fixed abutment, so that the first linear or straight portions of the two channels meet one another at an apex, said apex also defining said first fixed abutment, and the part-circular portions of the channels define an arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment.

5. A return spring mechanism according to Claim 4, having a single coil spring accommodated in one of said channels, wherein a stop portion is provided at a location on said arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment which is substantially diametrically opposite said apex, for cooperation with a stop portion which is rotatable with the handle to limit maximum rotation of the handle towards said unlatching or door release disposition.

6. A return spring mechanism according to any preceding claim, wherein the or each feature which is rotatable with the handle is provided on a member which is rotatably associatable with the handle.

7. A return spring mechanism according to any preceding claim, wherein said member which is rotatably associatable with the handle has at least one stop region on a peripheral surface region thereof radially outward of its axis of rotation to limit maximum rotation of the handle towards at least one of said door latching disposition and said unlatching or door release disposition by engagement of said at least one stop region against a cooperating fixed stop portion of the mechanism.

8. A return spring mechanism according to Claim 6 or Claim 7, wherein said member which is rotatably associatable with the handle is mountable on a shank or shaft portion of the handle for rotation therewith, said shank or shaft portion being bearingly receivable in a backing plate for association with the handle in a handle assembly.

9. A return spring mechanism according to Claim 8, wherein the or each said channel and fixed abutment are formed integrally in said backing plate.

10. A return spring mechanism according to Claim 6 or Claim 7, wherein said member which is rotatably associatable with the handle is accommodated within a cassette housing, a shank or shaft portion of the handle being~~;nsetmat hrattraugh-s2td cassette housing and rotal:tAe member, and the cassette housing being fixedly associatable with a door in an assembled condition of the handle and return spring mechanism.

11. A return spring mechanism according to Claim 10, wherein the or each said channel and fixed abutment are comprised in said cassette housing.

12. A door handle assembly having a handle pivotably mounted in a backing plate for rotation between a door latching disposition and an unlatching or door release disposition, and a return spring mechanism for urging the handle towards and into said door latching disposition from said unlatching or door release disposition the return spring mechanism having at least one coil spring compressively engaged between a first abutment which is fixed relative to the backing plate and a second abutment which is rotatable with the handle, wherein said at least one coil spring is accommodated in a channel which has a first linear or straight portion extending from said first fixed abutment and is continued by a part-circular portion within which said second abutment is arcuately displaceable.

13. A door handle assembly having a handle pivotably mounted relative to a backing plate for rotation between a door latching disposition and an unlatching or door release disposition, and a return spring mechanism accommodated within a cassette housing fixedly associated with said backing plate for urging the handle towards and into said door latching disposition from said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment which is fixed relative to the backing plate and a second abutment provided on a member which is rotatable with the handler wherein said at least one coil spring is accommodated in a channel provided within said cassette housing which has a first linear or straight portion extending from said first fixed abutment and is continued by a part-circular portion within which said second abutment is arcuately displaceable.

14. A return spring mechanism substantially as described herein with reference to and as shown in Figures 1 to 4 or Figures 5 to 8 of the accompanying drawings, or these Figures as modified having regard to Figures 9 and 10.

15. A return spring mechanism substantially as described herein with reference to and as shown in Figures 11, 12 or 13 of the accompanying drawings.

15. A return spring mechanism substantially as described herein with reference to and as shown in Figures 11, 12 or 13 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. A return spring mechanism for urging a door handle towards and into a door latching disposition from an unlatching or door release disposition, the door handle being pivotably mountable for rotation between said door latching disposition and said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment and a second abutment, the second abutment being provided on a member which is rotatably associatable with the handle, the first abutment being fixed relative to the direction of rotation of the handle, and said at least one coil spring being accommodated in a channel and retained therein by said member, wherein said channel has a first linear or straight portion extending from said first fixed abutment and continued by a part-circular portion within which said second abutment is arcuately displaceable, and said member which is rotatably associatable with the handle has a peripheral portion providing unobstructed access to said first linear or straight portion of the channel, in at least one disposition of the handle, for insertion of said at least one coil spring into said channel.

2. A return spring mechanism according to Claim 1, having two said channels, each channel extending from a respective first fixed abutment, said fixed abutments being disposed on diametrically opposite sides of the axis of rotation of the handle, and each channel being continued by a further linear or straight portion extending from said part-circular portion towards and to the first fixed abutment from which the other channel extends, so that the first linear or straight portion of each channel meets the further linear or straight portion of the other channel at an apex and the two apices thus defined are disposed on diametrically opposite sides of the axis of rotation of the handle, each apex itself also defining a first fixed abutment for one of said channels.

3. A return spring mechanism according to Claim 1 or Claim 2, having two coil springs, each accommodated in a respective said channel.

4. A return spring mechanism according to Claim 1, having two said channels, each channel extending from said first fixed abutment, and the part-circular portions of each channel being continued to meet one another at a location on the opposite side of the axis of rotation of the handle from said fixed abutment, so that the first linear or straight portions of the two channels meet one another at an apex, said apex also defining said first fixed abutment, and the part-circular portions of the channels define an arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment.

5. A return spring mechanism according to Claim 4, having a single coil spring accommodated in one of said channels, wherein a stop portion is provided at a location on said arcuately-continuous structure extending between the first linear or straight portions of the channels on the opposite side of the axis of rotation of the handle from said fixed abutment which is substantially diametrically opposite said apex, for cooperation with a stop portion which is rotatable with the handle to limit maximum rotation of the handle towards said unlatching or door release disposition.

6. A return spring mechanism according to any preceding claim, wherein the or each feature which is rotatable with the handle is provided on said member which is rotatably associatable with the handle.

7. A return spring mechanism according to any preceding claim, wherein said member which is rotatably associatable with the handle has at least one stop region on a peripheral surface region thereof radially outward of its axis of rotation to limit maximum rotation of the handle towards at least one of said door latching disposition and said unlatching or door release disposition by engagement of said at least one stop region against a cooperating fixed stop portion of the mechanism.

8. A return spring mechanism according to any preceding claim, wherein said member which is rotatably associatable with the handle is mountable on a shank or shaft portion of the handle for rotation therewith, said shank or shaft portion being bearingly receivable in a backing plate for association with the handle in a handle assembly.

9. A return spring mechanism according to Claim 8, wherein the or each said channel and fixed abutment are formed integrally in said backing plate.

10. A return spring mechanism according to any preceding claim, wherein said member which is rotatably associatable with the handle is accommodated within a cassette housing, a shank or shaft portion of the handle being insertable through said cassette housing and said member, and the cassette housing being fixedly associatable with a door in an assembled condition of the handle and return spring mechanism.

11. A return spring mechanism according to Claim 10, wherein the or each said channel and fixed abutment are comprised in said cassette housing.

12. A door handle assembly having a handle pivotably mounted in a backing plate for rotation between a door latching disposition and an unlatching or door release disposition, and a return spring mechanism for urging the handle towards and into said door latching disposition from said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment which is fixed relative to the backing plate and a second abutment provided on a member which is rotatably associatable with the handle, and said at least one coil spring being accommodated in a channel and retained therein by said member, wherein said channel has a first linear or straight portion extending from said first fixed abutment and continued by a part-circular portion within which said second abutment is arcuately displaceable, and said member which is rotatably associatable with the handle has a peripheral portion providing unobstructed access to said first linear or straight portion of the channel, in at least one disposition of the handle, for insertion of said at least one coil spring into said channel.

13. A door handle assembly having a handle pivotably mounted relative to a backing plate for rotation between a door latching disposition and an unlatching or door release disposition, and a return spring mechanism accommodated within a cassette housing fixedly associated with said backing plate for urging the handle towards and into said door latching disposition from said unlatching or door release disposition, the return spring mechanism having at least one coil spring compressively engaged between a first abutment which is fixed relative to the backing plate and a second abutment provided on a member which is rotatably associatable with the handle, and said at least one coil spring being accommodated in a channel provided within said cassette housing and retained therein by said member, wherein said channel has a first linear or straight portion extending from said first fixed abutment and continued by a part-circular portion within which said second abutment is arcuately displaceable, and said member which is rotatably associatable with the handle has a peripheral portion providing unobstructed access to said first linear or straight portion of the channel, in at least one disposition of the handle, for insertion of said at least one coil spring into said channel.

14. A return spring mechanism substantially as described herein with reference to and as shown in Figures 1 to 4 or Figures 5 to 8 of the accompanying drawings, or these Figures as modified having regard to Figures 9 and 10.