GB2262030A - A levelling workstation - Google Patents

Abstract

A workstation 10 in which raising or lowering of each edge of the work surface 12 is coordinated so that a level work surface is maintained. Screw-threaded actuators 34 are attached between the work surface 12 and its supporting frame 26, each of which have extendable driving members 36 to raise or lower the work surface 12 with respect to the frame 26. The movement of the two driving members 36 is synchronised by mechanical linkages 38 at each end of the work surface, formed of a pair of elongate members 40, 42, member 40 being pivotally connected at one end to the frame 16 and at the other end to the second member 42. The free end of member 42 is rigidly attached to a shaft 44 rotatably carried by the frame 26. Thus, vertical movement of one end of the work surface 12 becomes rotational movement of the shaft 44 which causes a corresponding movement in the linkage at the other end. <IMAGE>

Description

IMPROVED WORKSTATION This invention relates to an improved workstation especially one whereby the work surface is adjustable in height so that the table is easily usable by people in wheelchairs or with similar physical contraints.

The provision of workstations or work surfaces which are adjustable in height has been known previously.

Problems arise with such known arrangements in that it is difficult to provide a work surface which is capable of minute variation in height whilst still ensuring that both spaced apart edges of the work surface rise to the same amount and thus do not cause a sloping surface with consequent stability problems.

This situation arises from the use of ratchet type mechanisms where the height of a work surface can be modified only by fixed increments. Such arrangements would normally be operable manually in order to permit locking at the required height. However they do not permit height variation without manual operation and are thus unsuitable for use by physically constrained or disabled persons. Additionally, the height variation is by fixed non-changeable increments and thus the final height of the work surface may not be exactly as required.

Other means which could be or have been used are electrical, pneumatic or hydraulic telescopic actuators which permit the necessary minute height modification required for ease of use. Furthermore, such systems can be operated remotely by way of a simple control pack having one or two control elements. Thus, a disabled person could easily operate same without assistance.

The problem with such assemblies however, is that two such telescopic actuators will be required at each end of a work surface to provide adequate support during the raising thereof. It is understandably difficult to ensure that two independently operated actuators rise to exactly the same amount and thus consistently provide a substantially level work surface. Methods of solving this electronically are complex and not entirely satisfactory in that the minute height modification normally required has to be abandoned.

It would be advantageous to provide an improved workstation which overcomes the problems and is easily operable by a disabled person.

A first aspect of the present invention provides an improved workstation including a substantially horizonal work surface supported on a telescopically vertically extendable frame such that the work surface can be raised or lowered with respect thereto, the work surface being moveable by one or more actuators respectively connected to at least one end of the work surface, characterised in that the work surface is additionally supported by two linkages disposed adjacent to the respective opposed ends of the work surface and interconnected by a common shaft such that rotation thereof will cause a corresponding movement of each linkage.

Preferably, there are two actuators each with an adjacently disposed respective linkage which are each advantageously in the form of two substantially linear elongate members, one end of one member being fixedly attached to the shaft, its other end being pivotably attached to one end of the second member and the opposed end of the second member being pivotably connected to the work surface.

It will thus be understood that as the work surface is raised the mechanical linkage is moved causing a rotation of the common shaft. This rotation of the shaft is transferred to each of the two linkages and hence to the work surface ensuring that for any given movement of one actuator, the linkage and actuator at the opposed end of the work surface are also moved.

Preferably, the actuators are screw-thread actuators which are arranged to be lockable, so as to restrain the table against further movement.

Preferably, the actuators are controlled remotely by a control box which can either operate using standard cordless remote control procedures, i.e. infra-red signal transmission or can be arranged to be electrically connected by a wire or similar to one or both actuators.

The invention will be described further by way of example with reference to the accompany drawing in which the single figure is a sectional side view of a preferred embodiment of the invention with the work surface in a lowered condition.

Referring to the single figure, a first preferred embodiment of the invention provides an improved workstation 10 comprising a substantially horizontal work surface 12 which in the preferred embodiment is provided with an angled back rest 14.

The work surface 12 and back rest 14 are supported on a frame 16 which is provided at each end with two vertically depending legs 18, 20. These legs each locate in corresponding tubular receptor elements 22, 24 forming part of a support frame referred to generally by the reference numeral 26.

The support frame 26 is provided at each end of the work surface 12 with horizontally extending leg elements 28 which may or may not be provided with adjustable feet 30, 32 depending on the requirements and floor surface upon which the workstation is to be stood. It will thus be appreciated that the work surface 12 is capable of being displaced vertically with respect to the support frame 26 so that the height of the work surface 12 over the horizontal floor can be varied.

In order to permit such a variation two electrically operated screw-thread actuators 34 are provided at each end of the work surface 12. The actuator 34 is provided with a telescopically extendable driving member 36, the upper end of which is attached to the frame 16 supporting the work surface 12. Thus, extension (or contraction) of the element 36 causes the work surface 12 to be raised (or lowered) with respect to the support frame 26.

In order to synchronise movement of the two electric actuators 34 positioned at each end of the work surface 12, a mechanical linkage referred to generally by the reference numeral 38 is also provided. This mechanical linkage 38 comprises two elongate members 40, 42 located at each end of the work surface 12 and disposed substantially adjacent to the electric actuators. The respective upper end of first elongate member 40 is pivotally attached to the supporting frame 16 and its other end is pivotally connected to one end of the second member 42. The remaining free end of the second member 42 is respectively connected to a common shaft 44.

This shaft 44 is fixedly journalled in or on the support frame 26 and extends with its axis of rotation substantially parallel to the work surface 12. At its respective other end, the second linkage (not shown) is similarly attached adjacent to the second electric actuator (not shown).

By means of this shaft and linkage assembly when both electric actuators are operated the work surface will be raised causing a corresponding movement of the first elongate member 40 at each end of the table. By linkage through the pivot point the second member 42 will also be moved causing a rotation of the common shaft 44. As each of the second members 42 comprising the respective linkages 38 is fixedly linked to common shaft 44, it will be understood that there must be an identical movement of each of the second members 42. Thus, the work surface 12 will be displaced upwardly, or downwardly depending on the direction of movement of the actuators, in synchronization and one edge of the work surface 12 will not be raised to a different height, or at a different rate than its opposed edge.

The invention is not confined to foregoing details and variations made thereto within the scope of the invention. For example, further telescopic actuators 46 could be provided attached to the frame 16 so that the angle of the work surface 12 could be altered with respect to the user. Providing that the common shaft is sufficiently rigid in comparison to the work surfaces weight it is possible to construct the workstation having only one actuator. Other variations may also be possible.

Claims (6)

1. An improved workstation including a substantially horizonal work surface supported on a telescopically vertically extendable frame such that the work surface can be raised or lowered with respect thereto, the work surface being moveable by one or more actuators respectively connected to at least one end of the work surface, characterised in that the work surface is additionally supported by two linkages disposed adjacent to the respective opposed ends of the work surface and interconnected by a common shaft such that rotation thereof will cause a corresponding movement of each linkage.

2. A workstation as claimed in claim 1 in which there are two actuators each with an adjacently disposed respective linkage.

3. A workstation as claimed in claim 1 or 2 in which each linkage is provided by two substantially linear elongate members, one end of one member being fixedly attached to the shaft, its other end being pivotally attached to one end of the second member and the opposed end of the second member being pivotally connected to the work surface.

4. A workstation as claimed in any of claims 1 to 3 in which the actuators are screw-thread actuators which are arranged to be lockable, so as to restrain the table against further movement.

5. A workstation as claimed in any preceding claim in which the actuators are controlled remotely by a control box.

6. An improved workstation substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.