GB2432644A

GB2432644A - Extendable drive linkage

Info

Publication number: GB2432644A
Application number: GB0523974A
Authority: GB
Inventors: Andrew Martin Reason; Mario Rabaiotti
Original assignee: Andrew Reason Ltd
Current assignee: Andrew Reason Ltd
Priority date: 2005-11-25
Filing date: 2005-11-25
Publication date: 2007-05-30
Also published as: GB0523974D0

Abstract

A rotating drive linkage which allows relative longitudinal movement between the input and the output has a number of two-part arms, hinged in the middle and connected to the drive input and output by hinges. The input can move towards and away from the output axially, but relative rotational movement is prevented. The linkage may be used to connect a washing machine drum to a drive input.

Description

Drive Linkage The present invention relates generally to a rotating

drive linkage.

Many machines include parts or components that rotate about an axis, these parts often being driven by motorised means. In many cases, the component to be rotated is directly driven by a motor, via some gearing, but this is only feasible when there is a capacity for the motor and the component to be situated adjacent to one another. If there is a distance between the motor and the point of contact of the component then an intermediate linkage, or drive linkage, is used to span the gap and ensure that the force generated by one is applied to the other, and this can be in the form of a belt, shaft, chain or the like.

The constraints imposed by drive linkage are that they generally are not designed to accommodate relative movement between the components they link. Figure 1 of the accompanying drawings shows a belt system 100 utilised to link two components 110, 120 laterally. Such a system generally uses a tensioning pulley 130 to ensure there is no slack in the system. This allows a certain amount of relative movement between the input 110 and output 120 components, as demonstrated by moving the output 120b and accordingly moving the position of the tensioning pulley 130 b. However, this certainly cannot be done during operation. Referring now to Figure 2, a shaft orientated drive linkage 200 is shown, commonly used to link components 210, 240 longitudinally. An example is a prop shaft in a four-wheel drive car. Here there is the possibility for a small degree of elliptical movement between the two 210, 240, providing either one or the other is not fixed in space and further providing either end of the shaft 230 has a connection 220 allowing for multiple degrees of freedom. This movement is however primarily lateral and there is no provision for pure longitudinal separation.

It is an object of the present invention to provide a drive linkage in respect of two or more components that allows for longitudinal relative movement between the components.

In accordance with the present invention there is provided, a drive linkage for linking at least one rotatable input means and at least one rotatably mounted output means, such that rotation of said input means causes corresponding rotation of said output means via said drive linkage, wherein said drive linkage comprises at least one linkage member configured to enable longitudinal relative movement between said at least one input means and said at least one output means.

It will be understood that the longitudinal relative movement is in a direction substantially io parallel to the axis of rotation of said input and said output means.

In one exemplary embodiment, the linkage member may comprise an extendable and retractable linkage member for enabling said longitudinal movement. Alternatively, the linkage member may comprise means for selectively decoupling and recouping said at least one input means and said at least one output means. Preferably, in this case, the linkage member comprises means for selectively disconnecting and reconnecting said input means (i.e. the drive) relative to the output means.

Preferably, the drive linkage comprises at least one linkage arm pivotally connected at one end to said input means and at the other end to said output means, the linkage arm comprising a pair of substantially rigid, elongate bars, rotatably connected together. The drive linkage may comprise a plurality of said linkage arms. The linkage arm is beneficially configured such that in its contracted position it fits against or within the contours of a face of the input andlor output means.

Alternatively, said resiliently flexible linkage means may, for example, comprise a spring or one or more telescopic members.

Preferably, said at least one input means comprises a rotatably mounted shaft.

Preferably, said at least one output means comprises a rotatably mounted drum of an appliance such as a washing machine. In fact, the present invention extends to a laundry appliance having a rotatably mounted drum linked to a rotatable shaft via a drive linkage as defined above, and means for rotating said shaft so as to rotate said drum via said drive linkage.

Thus the above mentioned object is achieved by providing a linkage, such as a resiliently flexible linkage, connecting at least one input means to at least one output means, that efficiently communicates a rotational force therebetween, yet permits a degree of longitudinal movement relative to one another in the allowed plane.

These and other aspect of the present invention will be apparent from, and elucidated with reference to, the embodiment described herein.

An embodiment of the present will now be described, by way of example only, ad with reference to the accompanying drawings in which: Figure 1 is a schematic diagram illustrative of a drive linkage according to the prior art comprising a belt; Figure 2 is a schematic diagram illustrative of a drive linkage according to the prior art comprising a shaft; Figure 3 is a schematic side view illustrating a variable drive linkage according to an exemplary embodiment of the present invention, shown in its closed configuration; Figure 4 is a schematic side view of the drive linkage of Figure 3 shown in its open configuration; and Figure 5 is a schematic cross-sectional view of the drive linkage of Figure 3 shown in its open configuration.

Referring to Figures 3 to 5 of the accompanying drawings, a drive linkage 300 according to an exemplary embodiment of the present invention is illustrated in which the input and output components are a rotating shaft 302 and a washing machine drum 310 respectively. The rotating shaft 302 passes through a bearing 303, contained in a bearing housing 303a, to a hub 304 having a door closing mechanism 306 formed integrally therewith. The input linkage arms 308a are generally in the form of a back to front S' shape when viewed at a plane parallel to the back face of the drum 310, the S! having an elongated start and finish line and the two angles defining the middle section being inwardly angled at substantially 90 degrees. When viewed from a plane parallel to the side of the drum 310 the input linkage arms 308a again have a generally chicane' shape, to follow the surface contours of the circular depression formed centrally at the rear of the drum. At either end of the input-end linkage arms 308a there is formed a lateral circular aperture for receiving a linkage shaft that ultimately forms a hinge-joint when mated with corresponding output-end linkage arms 308b.

The input-end linkage arms 308a, in use, sit adjacent to a equal plurality of output-end linkage arms 308b, of substantially similar shape such that they fit side by side allowing a single common linkage shaft to pass through one of the concentric lateral circular apertures 31 2a, 31 2b of a pair such that they may rotate in this permitted plane relative to one another and as such form a hinge 312. As stated above the distal end of each input-end linkage arm 308a is connected to the hub 304. The distal end of an output-end linkage arms 308b is mounted to the rear face of the drum 310, therefore giving a configuration such that the rotating shaft 302 and the drum 310 are in rotatable communication in accordance with the input, yet the two are permitted to move longitudinally relative to one another.

It is the manner in which the arms 308a, 308b interact that enables the movement of the drum 310 relative to the drive arrangement, i.e. the hinge 312 permits the longitudinal displacement.

The manner in which the arms 308a, 308b are configured means also that there is no permitted relative movement (bar play) in terms of rotation and this is essential to the invention.

Similarly, in another exemplary embodiment, the linkage arms 308a, 308b could be replaced by a rotatably-rigid spring, that permitted separation between its two ends but was rigid enough to translate any applied rotation at one end to the other. In a further embodiment the linkage arms 308a, 308b could be replaced by a number of strong telescopic members, that would allow for longitudinal separation but contemporaneously were strong enough to provide the rotational translation.

Referring in particular to Figures 4 and 5, the drive linkage is shown in its open configuration 400, where the drive shaft 302 and the drum 310 are no longer immediately proximal.

Whereas in the configuration of Figure 3, the two sets of linkage arms 308a, 308b are adjacent along their length, in the illustrated configuration, they are now only so at the point where the common linkage shaft passes through one of the concentric lateral circular apertures 31 2a, 312b of a pair. The distal ends 314, 316 of the linkage arms 308a, 308b are thus separated through longitudinal movement of the drum 310, thereby providing a permanent linkage that io allows a longitudinal separation between the input and output components.

In an alternative embodiment, the drive may be coupled directly to the drum by means of a coupling that can be selectively disconnected and reconnected to enable the required longitudinal movement of the drum relative to the drive.

It should be noted that the above-mentioned embodiment illustrates rather than limits the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word "comprising" and "comprises", and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. The invention may be implemented by means of hardware comprising several distinct elements. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

CLAIMS: 1. A drive linkage for linking at least one rotatable input

means and at least one rotatably mounted output means, such that rotation of said input means causes corresponding rotation of said output means via said drive linkage, wherein said drive linkage comprises at least one linkage member configured to enable longitudinal relative movement between said at least one input means and said at least one output means.

2. A drive linkage according to claim 1, wherein said at least one linkage member comprises an extendable and retractable linkage member configured to enable said longitudinal relative movement.

3. A drive linkage according to claim 1, wherein said at least one linkage member comprises means for decoupling and recoupling said at least one input means and said at least one output means.

4. A drive linkage according to claim 3, wherein said at least one linkage member comprises means for selectively disconnecting and reconnecting said input means relative to said output means.

5. A drive linkage according to claim 2, wherein said drive linkage comprises at least one linkage arm pivotally connected at one end to said input means and at the other end to said output means, the linkage arm comprising a pair of substantially rigid, elongate bars, rotatably connected together.

6. A drive linkage according to claim 5, wherein said drive linkage comprises a plurality of said linkage arms.

7. A drive linkage according to claim 6, wherein said linkage arm is beneficially configured such that in its contracted position it fits against or within the contours of a face of the input andlor output means.

8. A drive linkage according to claim 2, wherein said at least one linkage member comprises a spring.

9. A drive linkage according to claim 2, wherein said at least one linkage member comprises a telescopic member.

10. A drive linkage according to claim 9, wherein said drive linkage comprises a plurality of said telescopic members.

11. A drive linkage according to any preceding claim, wherein said at least one input means comprises a rotatably mounted shaft.

12. A drive linkage according to any preceding claim, wherein said at least one output means comprises a rotatably mounted drum of an appliance such as a washing machine.

13. A laundry appliance having a rotatably mounted drum linked to a rotatable shaft via a drive linkage according to any one of the preceding claims, and means for rotating said shaft so as to rotate said drum via said drive linkage.