GB2183917A - Push button control means - Google Patents

Abstract

Control means, especially for a switch (8) of a washing machine or dishwashers, comprises a control panel (1, 2, 3) and a push button (7) mounted in the control panel to be movable perpendicularly to a viewing surface thereof. The push button has a skirt which extends substantially parallelly to the push button stroke axis (28) and supports blades (13) with abutment surfaces (17) which extend transversely to the axis (28). In the rest setting (undepressed) of the push button, the surfaces (17) abut against a forked lever (18, 19) that prevents depression of the push button. The lever has an actuating lug spaced from the push button and projecting from the side of the control panel, to allow pivoting of the lever (18, 19) against a spring (21). The push button can be retractive or held depressed by lever (18, 19) engaging slots (16) in the skirt. The lever (18, 19) can open (or close) additional switch contacts when moved to its latching position, to initiate electrical blocking. <IMAGE>

Description

SPECIFICATION Push button control means The present invention relates to control means and has particular reference to control of the stroke of a push button in a control panel.

Push buttons are often used as, for example, a mains switch in the control panel of a household appliance, such as a clothes washing or dishwashing machine. In an appliance of that kind, it is desirable that the push buttons cannot be operated by uninitiated persons, for example children. Consequently, it should be ensured that the appliance functions associated with the push buttons cannot be initiated by such persons.

For this purpose, it has been the practice to provide operating elements with complicated functions which may then be operable with difficulty even by initiated persons. Other types of operating elements to be secured against unauthorised actuation have been provided with locks operable by a key.

There remains a need for push button control means which can be secured against operation by uninitiated persons and the external impression of which is not distinguishable from simple operating elements without any such security measure.

According to the present invention there is provided control means comprising a control panel, a push button arranged in the panel to be movable into and out of a rest setting by displacement along an axis substantially perpendicular to a viewing face of the panel and including a skirt portion extending substantially parallelly to the axis, and a blocking element having a blocking portion engageable with an abutment surface portion of the push button to block movement thereof out of the rest setting and an actuating portion disposed at a spacing from the push button and operable to move the blocking portion out of engagement with the abutment surface portion.

In a preferred embodiment, the push button is guided rectilinearly in direction of its stroke movement and has an envelope with a generatrix extending at least nearly parallelly to the stroke axis. The push button has a thickness step which extends transversely to the stroke axis and below which, in the rest setting of the push button, engages a slide which has an actuating lug arranged remote from the push button.

By means of such a slide, the push button can be blocked so that its function cannot be initiated when the slide is engaged. The slide can in that case be operated by way of the actuating lug which is arranged at another part of the control panel. For release of the blocking, the slide can be brought out of engagement by means of the actuating lug and the push button then actuated.

Advantageously, the slide is guided in a guide such as a coulisse, arranged outside the movement zone of the push button and transversely to its stroke axis. Such a guide can be arranged to be flat and disposed inconspicuously behind the viewing surface of the control panel. Even as a plastics material part it ensures and easy actuation.

In another advantageous construction, the slide is part of a lever which is pivotable about a pivot axis lying externally of the push button and extending parallelly to its stroke axis. Such a lever, too, can be hidden inconspicuously behind the viewing surface of a control panel.

It is of advantage, particulariy in combination with the preceding feature, if that part of the slide which engages below the step has the form of a fork. The two fork ends can engage on either side of the stroke axis below the projection-like step and provide a blocking force which acts symmetrically on the push button so that it does not cant.

It may be of particular advantage if the slide is movable out of the rest setting against the force of a spring. In that case, the slide can be automatically returned to engagement with the step when the push button is released after actuation.

For preference, the push button is provided in its envelope with a groove which is arranged transversely to the stroke axis and which in an operative setting is disposed at the level of the slide. By this means blocking of the push button is possible in its operative setting so that the function initiated by the push button can be maintained. This is of particular importance in washing machines and dishwashing machines equipped with an electronic control equipment with a volatile program store. If the actuated mains push button switch is re-actuated, the program sequence entered into the store by the operator is lost.

If this occurs unintentionally, then any program in progress is interrupted without being able to be resumed at the same point.

In the case of such an electronically controlled household appliance, it is of advantage if the slide is operatively connected with an electrical signal contact which, in the engaged position of the slide delivers a signal. A monitoring signal for the electronic control equipment can then be derived in dependence on the push button blocking. Such a signal can advantageously initiate a switching measure for electrical blocking of at least a part of program input steps. For example, the blocking signal of an actuated mains push button switch can enable the effect of a switch or switch group of program input equipment.

After completed input, the initiation of a start signal can, in the presence of the blocking signal, serve for electrical blocking of all input functions so that merely stopping and starting of the set program is possible.

In order that inconspicuous blocking of the push button is secured on the one hand and a normal appearance of a control panel is retained on the other hand, it is of particular advantage if the actuating lug is arranged at the rim of the control panel. This makes possible association of the actuating lug with the push button in such a manner that the opera- - tor can actuate the lug and the push button at the same time by two fingers of one hand.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a vertical cross-section, along the line I-I of Fig. 3, of part of control means embodying the invention; Figure 2 is a plan view of this part of the control means with a viewing surface pane removed; and Figure 3 is a vertical cross-section along the line Ill-Ill of Fig. 2.

Referring now to the drawings, there is shown control means comprising a control panel with a two-part housing composed of base 1 and cover 2. The cover 2 itself is covered over by a viewing pane 3, the outer surface of which forms a viewing surface for an inscription. A mounting plate 4, which carries components 5 and a long-stroke push button switch unit 6, is arranged at about the level of the dividing line between the two housing parts.

The unit 6 consists of a push button 7 and a switch 8, a switch pin 9 of which can be actuated by the plunger pin 19 of the push button. The button 7 and the pin 10 together form a push button plunger. The switch 8 is fixed in its position by means of a centering pin 11 and clamped between the mounting plate 4 and the cover 2 by means of a fastening flange 12.

The push button 7 at its underside carries two guide blades 13, each of whidh has two projections 14 and 15. A groove 16 is formed between the projections and each lower projection 15 at its lower edge has a thickness step 17, i.e. the projections 15 form a lower surface.

In the illustrated setting of the push button, a fork 18 of a lever 19, which is mounted between the base 1 and the shell 2, engages below the step 17. Consequently, in this position of the push button, in which the switch 8 is not actuated, the button is secured against unintended depression.

The lever 19 is held in this setting by a spring 21 wound helically around a bearing 20. The lever 19 is pivotable against the spring force by means of an actuating lug 22 for movement out of the locking position, illustrated in solid lines in Fig. 2, into the position which is illustrated in dashed lines and in which the locking of the push button is cancelled. The lug 22 in that case protrudes out of an opening 23 in the side wall of the control panel housing and can be operated simultaneously with the push button by two fingers of one hand. In the unlocked lever setting, the switch 8 is actuable through depression of the push button. In that case, the guide blades 13 are moved into the lower setting, illustrated in dashed lines in Fig. 1, so that the grooves 16 are disposed at the height of the fork 18.If the actuating lug 22 of the lever 19 is now released, then the fork 18 engages into the groove 16 and locks the push button in the actuated setting.

Apart from switch contacts 24 for the basic function of the switch 8, two further contacts 25 and 26 are arranged at the switch housing, the contact 25 being electrically connected with an input of electronic control equipment and the signal contact 26 serving as a monitoring contact for the engaged setting of the lever 19. The contacts 25 and 26 are closed when the lever 19 does not engage, whilst the actuating bridge 27 of the lever 19 in the illustrated engaged setting raises the contact 25 off the contact 26. The signal resulting from opening of the contacts 25 and 26 can then initiate a switching measure for the electrical blocking of at least a part of program input steps for the electronic control equipment.

In the illustrated embodiment, the contacts 25 and 26 are rest contacts, i.e. they are closed in the unactuated state and are opened only on actuation through the actuating bridge 27. The contacts can, of course, also be so arranged that they are open in the rest state and closed only on actuation through the actuating bridge 27.

Claims (10)

1. Control means comprising a control panel, a push button arranged in the panel to be movable into and out of a rest setting by displacement along an axis substantially perpendicular to a viewing face of the panel and including a skirt portion extending substantially parallelly to the axis, and a blocking element having a blocking portion engageable with an abutment surface portion of the push button to block movement thereof out of the rest setting and an actuating portion disposed at a spacing from the push button and operable to move the blocking portion out of engagement with the abutment surface portion.

2. Control means as claimed in claim 1, wherein the blocking element is guided to be slidable in guide means disposed outside the zone of displacement of the push button and guiding the blocking element to be movable in a direction transverse to said axis.

3. Control means as claimed in claim 1, wherein the blocking element is arranged to be pivotable about an axis spaced from the push button and extending substantially parallelly to said axis of displacement of the push button.

4. Control means as claimed in any one of the preceding claims, wherein the blocking portion is fork-shaped.

5. Control means as claimed in any one of the preceding claims, comprising resilient means arranged to maintain engagement of the blocking portion with the abutment surface portion and to resist said movement of the blocking portion of such engagement.

6. Control means as claimed in any one of the preceding claims, wherein the push button is provided with a groove in which the blocking portion is so engageable in an operative setting of the push button as to block movement of the push button out of the operative setting.

7. Control means as claimed in any one of the preceding claims, comprising contact means to provide an electrical signal when the blocking portion is engaged with the push button.

8. Control means as claimed in claim 7, comprising electrical means arranged to be disposed in an inoperative state in the presence of such signal.

9. Control means as claimed in any one of the preceding claims, wherein the actuating portion is disposed at an edge region of the control panel.

10. Control means substantially as hereinbefore described with reference to the accompanying drawings.