GB2139002A

GB2139002A - Actuators

Info

Publication number: GB2139002A
Application number: GB08410795A
Authority: GB
Inventors: Roger James Parsons; Robert Anthony Meek
Original assignee: Hotpoint Ltd
Current assignee: Hotpoint Ltd
Priority date: 1983-04-27
Filing date: 1984-04-27
Publication date: 1984-10-31
Also published as: GB8410795D0

Abstract

A push-button actuator 3 for operating a device such as an electrical switch 1, has associated with it an inhibitor 14 capable of being set into one rotational position which enables the push-button to be depressed to an extent which actuates the device, or to another position in which it prevents the depression of the push-button to said extent. Such an arrangement when applied to a push-button switch enables the switch, for example the mains switch of a washing machine, to be locked in either the "on" or the "off" position. The actuator may also be used to lock a drawer of a soap or detergent dispenser of the washing machine in the closed position. <IMAGE>

Description

SPECIFICATION Actuators This invention relates to push-button actuators for varying the relative positions of two inter-related relatively movable members, and is especially, though not exclusively, concerned with push-button actuators for operating electrical switches.

An object of the invention is to provide a means of inhibiting the functioning of such actuators.

In accordance with the invention a push-button actuator arranged to act on a movable member to produce a predetermined change in its position relative to an inter-related member, has, associated with the push-button, an inhibitor element capable of being set into one position in which it enables the push-button to be depressed to an extent which produces said predetermined change in the position of the movable member or into another position it prevents such change.

Preferably the movement of the inhibitor member into said other position prevents the depression of the push-button to an extent which produces the predetermined change in the position of the movable member. Thus the inhibitor element may, for example, be rotatable about the axis of movement of the push-button into a first position in which it permits the button to be depressed sufficiently to produce said predetermined change in the position of the movable member, or into a second position in which at least one surface of the element engages a stop on depression of the button and effectively obstructs the full movement of the button, thereby preventing it from effecting the predetermined change of position of the movable member.

Alternatively the inhibitor element may be rotatable into a first position in which it engages the movable member on depression of the push-button, in a manner which enables it to produce said predetermined change in the position of the member, or into a second position in which it remains disengaged from the movable member on depression of the push-button so that it cannot be actuated thereby.

The inhibitor element in each case is conveniently carried by or forms part of a member rotatably supported within a housing, the whole assembly constituting the push-button. Conveniently the rotatable member has a front surface which does not protrude beyond the front face of the housing so that it cannot readily be rotated manually, and is provided with a shaped depression so that it may be rotated by a suitably shaped implement. The depression could, for example, be in the form of a slot, so as to be operable by a screwdriver or an edge of a coin but other shapes, possibly operable only by a special tool, could alternatively be used.

Such an arrangement has the advantage that when the inhibitor element is set into said other position inadvertent operation of movable member by the push-button is effectively prevented.

The device being actuated may, for example, comprise a electric switch of the type having a spring-loaded plunger depressable by a push-button to change the condition of the switch from "on" to "off" or vice versa, and the switch remaining in the changed condition on release of the push-button until the latter is again depressed which causes the switch to revert to its original condition.

Such a switch may for example constitute the mains on-off switch for a washing machine or other electrical appliance.

The invention is of particular advantage in the case of microprocessor-controlled automatic washing machines, where switching off the machine during a washing cycle could result in the programme being returned to the start position and is obviously undesirable as it could in some cases harm fabrics being washed if left for an unduly long period in a hot state. Not only would it prevent accidential operation of the main switch but also interference from children. Moreover it could be used to prevent the machine from being switched on when not required.

However the invention is not restricted to the operation of electric switches or to washing machines but could also have application to other devices having a member movable from one position to another by means of a push-button, in which it is desired to inhibit such movement of the member.

Two different embodiments of the invention will now be described by way of example with reference to Figures 1 to 5 of the accompanying schematic drawings, in which Figure 1 illustrates a perspective view of a pushbutton actuator as applied to an electric switch, Figures2and 3 illustrate a side section and a plan section of the assembly shown in Figure 1, Figure 4 shows a plan view of the assembly in the "lock" position, and Figure 5 represents a side view of a second embodiment applied to a release mechanism.

Referring first to Figures 1 to 3 of the drawings, 1 is an electric push-button type switch of known kind having a spring loaded plunger 2 which is depressable by the push-button to change the condition of the switch i.e. from "on" to "off" or vice versa, the switch remaining in the changed condition on release of the push-button, and in which a subsequent depression of the plunger 2 results in the switch reverting to its original condition. Such switches are themselves well known and the construction of the switch, which is not relevant to the present invention, will not be described in detail. The switch may, for example, constitute the mains on-off switch for an microprocessor-controlled automatic washing machine, and may be located on the control panel of the machine.

The switch plunger 2 is operable by a push-button 3 of square cross-section slidably mounted in a correspondingly shaped guide hole located in the control panel 4 of the washing machine.

The push-button comprises a hollow outer casing 5 of moulded plastics material supporting within it a generally cylindrical inner member 6, also of moulded plastics material, rotatable within the casing 5 about its axis.

Each of the four sides of the casing is formed with two parallel slots 7 extending from the rear edge and forming between them a resilient tongue 8. Each tongue 8 has, at its free end, an inwardly directed rib 9 which engages within an annular groove 10 adjacent the rear of the inner member 6, and serves to retain the member within the casing with its closed front face 11 generally flush with the front 12 of the casing. This face is formed with a groove 13 which enables the member 6 to be rotated, with the edge of a coin or a screwdriver or like implement, about its axis relative to the casing 5.

The rear end of the inner member 6 projects beyond the casing 5 and carries two arms 14 projecting radially from it diametrically opposite one another, the end parts 15 of which arms turn rearwards for a short distance and carry two inwardly directed lugs 16 spaced slightly from the main parts of the arms so that grooves 17 are formed between them and the main parts of the arms 14.

These grooves 17 accommodate the edge of a radially directed flange 18 carried buy a member 19 non-rotatably fixed to the protruding end of the switch plunger 2, the member 19 also having a forwardly extending cylindrical projection 20 which fits closely within the inner cylindrical member 6 of the push-button 3; the flange 18 secures the pushbutton 3 against relative longitudinal movement relative to the switch plunger 2, but at the same time permits the inner member 6 of the push-button to be rotated relative to it.

The two rearwardly extending end parts 15 of the arms 14 of the inner member 6 of the push-button project beyond the lugs 16, and the arrangement is such that when the member is in the position illustrated in Figures 2 and 3 with the groove 13 horizontal and the arms 14 vertical the push-button 3 can be depressed sufficiently to operate the switch 1, either to switch it "on" or "off" as the case may be.

However when it is desired to lock the switch in one or other of these conditions, the inner member 6 of the push-button 3 is turned sothatthe groove 13 extends vertically and the arms 14 horizontally as shown in Figure 4. In this position the rearwardly projecting end parts 1 5 of the arms 14engagethe surfaces of projections 21 on the front of the switch casing 22. This prevents the switch plunger 2 from being depressed for a sufficient distance to actuate the switch 1, which therefore remains locked in eitherthe "on" or "off" position in which it was previously set.

Thus with the member 6 set in this second position inadvertent or unauthorised actuation of the switch 1 to stop or start the washing machine at instants when it is undesirable to do so is effectively prevented, the member having to be turned through 90 to its original position as shown in Figures 1 to 3 before the switch 1 can be operated.

An alternative embodiment of the invention as applied to a catch 31 securing the drawer of a soap or detergent dispenser of an automatic washing machine is illustrated in Figure 5.

The push-button 3 itself is similar two that described with reference to Figures 1 to 4 and is similarly located in a suitably shaped guide hole in the control panel 4 of the washing machine.

The dispenser drawer 32, which is illustrated in diagrammatic form only, is held in the closed position against one or more springs (not shown) by a spring-loaded catch 33. In one position of the inner member 6 of the push-button 3, i.e. with the groove 13 in its horizontal and the arms 14 vertical as shown, the push-button can be depressed sufficiently to actuate the catch 33 releasing it from a recess 35 in an edge of the drawer 32, allowing the drawer spring to push it forward and prevent reengagement of the catch 33 in the recess 35.

Subsequent closure of the drawer causes the reengagement of the catch 33 and recess 35 which again secures the drawer in the closed condition.

However if the inner member 6 of the push-button is turned through 90", so that the arms 14 are horizontal, the rearwardly projecting end parts 15 of the arms engage suitably positioned stop members (not shown) thereby restricting the distance by which the push-button 3 can be depressed, such that it is insufficient to release the catch 33 from the recess 35. Consequently the drawer remains locked in the closed position. It is also possible to lock the drawer in the open position, should this be required for any reason by providing a further recess in the edge of the drawer for example as at 3 which is engageable by the catch 33 when the drawer is opened.

In a modification the member 6 may carry a projection which itself engages part of the drawer when the member is rotated into one position, and thereby prevents the drawer from being opened, and is such that on rotation of the member into another position, as by a coin or the like inserted into the slot 13, the projection is disengaged from the drawer and allows the drawer to be opened.

Although the invention has been described in its application to washing machines, it will be appreciated that it could also be utilised for other purposes where it is required to inhibit the operation of a push-button for preventing undesired actuation of an electrical switch or other device.

Claims

1. A push-button actuator arranged to act on a movable member to produce a predetermined change in its position relative to an inter-related member, having, associated with the push-button, an inhibitor element capable of being set into one position in which it enables the push-button to be depressed to an extent which produces said predetermined change in the position of the movable member or into another position it prevents such change.

2. An actuator according to Claim 1 wherein the movement of the inhibitor element is such as to prevent the depression of the push-button to an extent which produces said predetermined change in the position ofthe movable member.

3. An actuator according to Claim 2 wherein the inhibitor element is rotatable about the axis of movement of the push-button into a first position in which it permits the button to be depressed sufficiently to produce said predetermined change in the position of the movable member, or into a second position in which at least one surface of the element engages a stop on depression of the button and effectively obstructs the full movement of the button, thereby preventing it from effecting the predetermined change of position of the movable member.

4. An actuator according to Claim 1 wherein the inhibitor element is rotatable into a first position in which it engages the movable member on depression of the push-button, in a manner which enables it to produce said predetermined change in the position of the member, or into a second position in which it remains disengaged from the movable member on depression of the push-button so that it cannot be actuated thereby.

5. An actuator according to any preceding Claim wherein the inhibitor element is carried by or forms part of a member rotatably supported within a housing, the whole assembly constituting the pushbutton.

6. An actuator according to Claim 5 wherein the rotatable member has a front surface which does not protrude beyond the front face of the housing so that it cannot readily be rotated manually, and is provided with a shaped depression so that it may be rotated by a suitably shaped implement.

7. An actuator according to Claim 6 wherein the depression is in the form of a slot.

8. An actuator according to any preceding Claim for an electric switch of the type having a springloaded plunger depressable by a push-button to change the condition of the switch from "on" to "off" or vice versa, and the switch remaining in the changed condition on release of the push-button until the latter is again depressed which causes the switch to revert to its original condition, wherein the actuator is positioned to permit the push-button to depress the plunger to an extent which changes the condition of the switch when the inhibitor is in said one position, and the operation of the switch by the push-button being prevented when the inhibitor is in said other position.

9. A washing machine having a main on-off electric switch of the type having a spring-loaded plunger depressable by a push-button to change the condition of the switch from "on" to "off" or vice versa, and the switch remaining in the changed condition on release of the push-button until the latter is again depressed which causes the switch to revert to its original condition, and including an actuator in accordance with any one of Claims 1 to 7 wherein the actuator is positioned to permit the push-button to depress the plunger to an extent which changes the condition of the switch when the inhibitor is in said one position, and the operation of the switch by the push-button being prevented when the inhibitor is in said other position.

10. A washing machine having a dispenser drawer, a catch which engages the drawer, when the drawer is closed, to prevent it from being opened, and which is movable into a position in which it releases the drawer and permits it to be opened, and an inhibitor element having a first position in which the catch is prevented from releasing the drawer, and being rotatable into a second position which allows the action to release the drawer.

11. Awashing machine according to Claim 10 wherein the inhibitor element is supported for rotation within a housing and has a front surface which does not protrude from the front face of the housing so that it cannot readily be rotated manually, and is provided with a shaped depression so that it may be rotated by an appropriately shaped instrument.

12. A washing machine according to Claim 10 or 11 in which the catch comprises a spring loaded member arranged to engage the drawer, when the latter is closed, to prevent the drawer from being opened, which member is movable, on depression of a co-operating push-button, against the spring loading, into a position in which it releases the drawer and allows it to be opened, and the inhibitor element has a first position in which it allows the push-button to be depressed sufficiently to move the catch member into the released position, and another position in which at least one surface of the element engages a stop, on depression of the push-button, which stop obstructs the full movement of the button and prevents it from moving the catch member into the release position.

13. An actuatorforan electric switch substantially as shown in and as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

14. An actuator for a dispenser drawer substantially as shown in and as hereinbefore described with reference to Figure 5 of the accompanying drawings.

15. Awashing machine incorporating an actuator according to Claim 13 or 14.