GB2109905A

GB2109905A - Hand operable control devices

Info

Publication number: GB2109905A
Application number: GB08229867A
Authority: GB
Inventors: Peter Robert Michael
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1981-10-21
Filing date: 1982-10-19
Publication date: 1983-06-08

Abstract

A hand operable control device which is operated by wrist flexure alone includes a fixed base member 2, a control member 10 having a manually grippable lever 13 and being mounted on the base member 2 for pivotal movement about two orthogonal axes X-X and Y-Y. Potentiometers 6 and 12 measure angular displacement about axes X-X and Y-Y respectively. The manually-grippable lever is positioned so that when gripped by an operator, the wrist flexure region of the operator lies on or adjacent the intersection of axes X-X and Y-Y. If the device was head operated the pivotal axes would be adjacent the neck flexure region of the operator. <IMAGE>

Description

SPECIFICATION Hand operable control devices This invention relates to hand-operable control devices and in particular to devices which may be operated solely by flexure of the wrist of a user.

In known hand-operable devices a control arrangement is provided which comprises a manually-grippable lever pivotally mounted on a fixed bracket, displacement of the lever effecting displacement of a control device, either directly or indirectly, or producing an output signal which is then translated into the required displacement. Such control devices may provide control through direct mechanical linkwork, or serve to operate hydraulic valves, or operate on electrical transducers to provide electrical output signals. In such devices, the pivot point or axis about which the lever pivots is usually spaced by a substantial amount from the wrist flexure region of the user; thus movement of the lever is effected by a lateral or compound movement of the operator's hand, rather than byflexure alone.

According to this invention, there is provided a hand-operable control device for operation by wrist flexure of an operator including a fixed base member, a control member having a manually-grippable lever portion and being connected to the fixed base member for turning movement about a turning axis, and measuring means for measuring angular displacement of the control member with respect to the base member, the manually-grippable lever portion being spaced from the turning axis such that when it is gripped by the operator, the wrist flexure region of the operator lies on or adjacent said turning axis.

By the term "wrist flexure region" in this Specification is meant that point or region of the wrist of a person about which the hand pivots in dorsiflexionl palmerflexion and abduction/adduction.

Preferably, said control member is connected to the fixed base member for turning movement about two orthogonal turning axes, the wrist flexure region of an operatorwhen gripping the manuallygrippable lever portion lying at or adjacent the intersection of said orthogonal turning axes.

Conveniently, there is provided support means associated with the hand-operable control device adapted to support the fore-arm of the operator in generally fixed relationship with respect to the base member.

By way of example only, one specific embodiment of hand operable control device constructed in accordance with this invention and certain modifications thereof will now be described in detail, reference being made to the accompanying drawings in which Figure 1 is a rear view of a hand-operable control device; Figure 2 is a side view of the device of Figure 1, and Figure 3 is a side view of part of a modified hand control device.

Referring to Figure 1,the device comprises a hollow cylindrical base member 1 which is attached to a structural member 2. A yoke member 3 having a depending hollow stub shaft 4 is mounted for rotation in base member 1 by means of bearings 5 about an azimuth axis XX. The body of a potentiometer 6 is secured in the lower end of hollow stub shaft 4, the wiper rotor of the potentiometer being concentric with axis XX and secured to a base plate 7 which itself is secured to the lower end of the hollow cylindrical base member 1. Hence, as the yoke member is turned about azimuth axis X - X the position of the wiper in the potentiometer changes accordingly.

The yoke 3 also includes a pair of upstanding arms 8 between which is supported the platform portion 9 of a control member 10, by means of bearings 11 for rotation about an elevation axis Y - Y. A further potentiometer 12 is secured to one of the arms 8, its wiper rotor being concentric with axis W and secured to a side of the platform member. The device is constructed so that axes XX and YY are coincident at point W. The control member includes a manually-grippable lever 13 spaced from pointW so that when a user grips the control lever, the pivotal region of the wrist joint of the user lies at or adjacent said point W. As shown in Figure 2, the lever 12 is inclined forwardly of axis XX to suit the condition of the grip of a user when his arm is generally horizontal.

When the control member 10 is displaced in azimuth, the wiper of potentiometer 6 moves to produce a signal indicative of the displacement.

When the control member is displaced in elevation, the wiper of potentiomer 12 moves to produce a signal indicative of the displacement. The signal is then used to move the apparatus under control.

In use, the user grips the lever 6, and he may effect movement of the control member 10 about the azimuth axis XX by dorsiflexion/palmerflexion and movement about the elevation axis YY by abduction/ adduction. These control movements are effected by flexure of the wrist alone, and do not require any axial or transverse movement of the arm. Thus this arrangement is of particular use where the control device is being used to effect control of a vehicle subject to violent movements, for example a vehicle moving over rough ground. In this case, if the control device and the user's arm are fixed relative to one another, for example by attaching the device to an arm rest and strapping the user's arm to the same rest, then precise operation of the device may be effected by wrist flexure alone, unaffected by any movement of the arm rest or other parts of the user's body.

Referring to Figure 3, the device may also include compression springs 14 arranged to biass the control member 10 to a neutral or median position both in the azimuth and elevation senses when the lever 6 is released; this self-centering action may be assisted by the provision of a detent mechanism. In addition to providing a self-centering action, this modification also provides a 'feel' characteristic for the device. This may be enhanced further by providing means whereby the internal friction resisting movement of the control member 10 may be made adjustable to suit the operator or the device may be provided with some degree of feedback to enable the operator to acquire a greater degree of control.

It will also be appreciated that whilst the above embodiment of control device is operable in the azimuth and elevation senses alone, the invention extends also to devices which are operable also about a third axis. For example, the hollow cylindrical member could be mounted on the structural member 2 by means allowing turning movement about an axis passing through point.

Furthermore, the invention also extends to devices other than those operable by hand, in which devices the pivotal axis of axes of the control device lie on or adjacent a natural flexure region of the Operator's body. For example in a head-operated device, the pivotal axis or axes would lie adjacent the neck flexure region of the operator.

Claims

1. A hand-operabie control device for operation by wrist flexure of an operator, including a fixed base member, a control member having a manuallygrippable lever portion and being connected to the fixed base memberforturning movement about a turning axis, and measuring means for measuring angular displacement of the control member with respect to the base member, the manually-grippable lever portion being spaced from the turning axis such that when it is gripped by the operator, the wrist flexure region of the operator lies on or adjacent said turning axis.

2. A hand-operable control device according to Claim 1, wherein the control member is connected to the fixed base member for turning movement about two orthogonal turning axes, the wrist flexure region of the operator when gripping the manuallygrippable lever portion lying at or adjacent the intersection of said orthogonal turning axes.

3. A hand-operable control device according to Claim 1 or Claim 2, which further includes support means adapted to support the forearm of the operator in generally fixed relationship with respect to the base member.

4. A hand-operable control device, substantially as hereinbefore described with reference to, and as illustrated in, any of the accompanying drawings.