NZ200396A

NZ200396A - Push button actuator plate for placement over and protection of a push button keyboard

Info

Publication number: NZ200396A
Application number: NZ200396A
Authority: NZ
Inventors: H Ruzic
Original assignee: Int Standard Electric Corp
Priority date: 1981-05-07
Filing date: 1982-04-23
Publication date: 1985-07-12
Also published as: ATE16539T1; EP0064615A2; AU8319682A; DE3267364D1; DE8113363U1; EP0064615B1; EP0064615A3; AU551245B2

Abstract

1. Telephone set with a pushbutton dialling keypad whose keytops (3) have hat-shaped cross sections, are guided in a cover (2) and are each, with the aid of a flexible member (4; 9), connected to a plunger (5; 10) serving to actuate the contacts (7; 11), characterized in that said cover (2) is placed on to a guide plate (1) having upright tubular extensions (6) which are overlapped by said keytops (3) and in which said plungers (5; 10) are guided, and that said guide plate (1), said cover (2) and said keytops (3) are all made of metal.

Description

200396 Priority Date\.7? I j Complete Specification Filed: Class: .tff.'.l.

Publication Dote: .... L J9B5,, t ♦P.O. Journal. No: I.... oneifUL NEW ZEALAND .

THE PATENTS ACT, 1953.

COMPLETE SPECIFICATION "ACTUATING MEANS FOR PUSH-BUTTON KEY-BOARD ASSEMBLY" WE, INTERNATIONAL STANDARD ELECTRIC CORPORATION, a Corporation of the State of Delaware, United States of America, of 320 Park Avenue, New York 22, New York, United States of America, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 200398 This invention relates to a means for actuating switches of a push-button key-board assembly and particularly, though not exclusively, means for actuating switches of a pushbutton dialling key-board of a telephone apparatus, especially a coin telephone.

When electronic apparatus which incorporate push-button key=board assemblies are located in certain environments, such as, for example, factories, the key-board is prone to damage; and in the case of coin operated public telephones, may be subject to acts of vandalism.

It is an object of the present invention to provide an actuating means for actuating switches of a push-button keyboard assembly, whose design is such that it renders the keyboard assembly, virtually damage proof, a further object of the invention is to provide an actuating means which can be adapted to function with various kinds of push-button key-board assemblies without the need to modify the assembly chosen.

Accordingly there is provided an actuating means for actuating switches of a push-button key-board assembly, comprising a first and a second planar member arranged in a fixed spaced relationship, said first planar member including an array of apertures in each of which is slidably located a push-button housing, a top portion of said housing lying in a plane substantially parallel to the plane of the first planar member, and a wall portion of said housing extending from said top portion which together with the said top portion defines a hollow interior space whose 20039 longitudinal axis is coaxial with the longitudinal axis of a tubular member extending from an aperture in the second planar member the outer surface of the tubular member being slidably conterminous with the inner surface of the wall portion, said wall portion including an outwardly extending shoulder which abuts the interfacing surface of the first planar member, wherein an actuating plunger is coaxially located at least within the tubular member and arranged such that upon selective axial displacement of the push-button housing the actuating plunger is axially displaced for transmitting axial movement to an associated push-button switch of the said pushbutton. key-board assembly^ Some embodiments of the invention will now be described with reference to the drawings in which: Fig. 1 is a cross-sectional view of an actuating means according to the invention associated with a push-button keyboard assembly having foil type contacts which are directly actuated by the actuator means.

Fig. 2 is a cross-sectional view of a second embodiment of the actuating means of the present invention associated with a push-button key-board assembly in which the actuating means indirectly operate the switch contacts by actuating the push-buttons of the assembly.

Referring to Fig. 1, a metal guide plate 1 which, at the location of the push-button is provided with upright ■v \ ' • ■ - - u XI w J L—*-r~*. . 1 4 JAN 1985 PATErJT OFFICE 200396 tubular members 6, is placed directly onto contact foils 13. The number and lamination thereof depends on the purpose of practical application. At those points at which the plungers 5, guided in'..the).'bores 17 of the tubular member 6, act upon the contact foils.13, the conductor leads 7 of different foil layers are brought into contact with one another when the associated spring-loaded push-button is depressed.

The plungers 5 are mushroom-shaped with the respective cap 14 thereof being directed down-wardly towards the contact foils 13, while the stalk 15 is directed upwardly, Over the latter there is slipped one end of a helical compression spring 4 whose other end abuts on the respective push-button 3. The push-button 3 have hat-shaped crods sections. The walls of the cavity 16 serve as a guide on the upright tubular member 6 of the guide plate 1. This cavity 16 serves as the receptacle for the upper end of the helical compression spring 4 which restores the push-button to its normal position.

The outer walls of push-button 3 are guided in corresponding recesses 18 provided in a cover 2 which is placed on to the guide plate 1- The cover has downwardly extending outside walls 19 and is provided with reinforcing ribs 20 between the individual push-buttons. The distance of the cover 2 from guide plate 1 determines the travel of the push-buttons, because the push-buttons 3 are provided at their open end with a collar 21 which, in one direction, abuts the cover 2,and, 2 003 96 in the other direction, abuts the guide plate 1.

The cover 2, the guide plate 1 and the push-buttons 3 are all made of metal, preferably of an aluminium diecasting alloy. In this way the push-button assembly is insensitive to violent vibration and fire. It is also protected against liquids, because only small amounts can enter around the key-buttons and then remain in the space between the cover 2 and the guide plate 1. In order to enable drainage from this space, discharge bores 8 are provided for, e.g., at the butt joint between the cover and the guide plate. Considering that the key-board assembly is installed on a slanting or vertical surfaces, it is sufficient for the openings 8 to be provided on the bottom side only.

The embodiment as shown in Fig. 2 comprises a guide plate 1, a cover 2 and push-buttons 3 similar to those described in relation to Fig. 1. This arrangement is intended to protect the normal, commercially available types of push-button dialling key-boards which are incapable of withstanding mechanical and chemical abuse, and is provided without the contact foils 13 as used in the embodiment shown in Fig. 1. Moreover the resetting springs 4 are emitted because the push-buttons 11 of the commerically available type of pushbutton dialling keyboard 12 are already provided with such springs. Instead of this, the plungers 10 are designed to be so long as ta bridge the distance from the underside of the guideplate 1 to 2003 9 the inside of the key-button 3. Between this inside of the key-button 3 and the upper end of the plunger 10 there is inserted a resilient part 9 of rubber or the like for serving as a buffer.

In both embodiments the forces caused by impact are absorbed by the key-button 3 and the guide plate 1, the normal actuating forcc is transferred to the push-buttons 11 or the contacts via the resilient part 9 or the hilical compression spring 4 respectively. Liquids are prevented from entering the push-button keys or the contacts. Likewise, all sensitive parts are protected from the effects of heat.

Claims

20C396 What we claim is:-

1. An actuating means for actuating switches of a pushbutton key-board assembly, comprising a first and a second planar member arranged in a fixed spaced relationship, said first planar member including an array of apertures in each of which is slidably located a push-button housing, a top portion Of said housing lying in a plane substantially parallel to the plane of the first planar member, and a wall portion of said housing extending from said top portion which together with the said top portion defines a hollow interior space whose longitudinal axis is coaxial with the longitudinal axis of a tubular member extending from an aperture in the second planar member the outer surface of the tubular member being slidably conterminous with the inner surface of the wall portion, said wall portion including an outwardly extending shoulder which abuts the interfacing surface of the first planar member, wherein an actuating plunger is coaxially located at least within the tubular member and arranged such that upon selective axial displacement of the push-button housing the actuating plunger is axially displaced for transmitting axial movement to an associated push-button switch of the said push-button key-board assembly.

2. An actuating means as claimed in claim 1, wherein a resilient member is arranged so that transmission of axial displacement of the push-button housing to the associated push-button - 7 - N.Z. PATENT OFFICE - 1 MAR 1985 RECEIVED 200396 switch is via the resilient member and. the actuating plunger.

3. An actuating means as claimed in claim 2, wherein the resilient member is a helical spring interposed between the said top portion interior surface and the actuating plunger.

4. An actuating means as claimed in claim 2, wherein the resilient member is a piece of resilient material interposed between the said top portion interior surface and the actuating plunger.

5. An actuating means as claimed in any one of the preceding claims, wherein the first and second planar member and the said slidably located push-button housings are metal.

6. An actuating means as claimed in any one of the preceding claims, wherein a discharge bore hole is. provided which communicates between the space defined by the first and second planar members and the exterior of the actuating means for the discharge of liquid.

7. An actuating means for actuating switches of a pushbutton key-board assembly, substantially as herein described with reference to Figs. 1 and 2 of the accompanying drawings.

8. A telephone apparatus incorporating a push-button keyboard assembly comprising a planar array of push-button switches arranged in rows and columns, and including an actuating means as claimed in any one of the preceding claims, the actuating means being mounted over the said planar array of push-button switches and aligned therewith such that 8 PATEPJT OrPlCE 200396 selective axial displacement of the said actuating plunger operates an associated push-button switch of the said assembly.

9. A telephone apparatus as claimed in claim 8, wherein each said push-button switch of the said assembly has opera-tively associated therewith a push-button, which is actuated by an associated actuating plunger of the actuating means thereby operating the said push-button switch of the assembly.

10. A telephone apparatus as claimed in claims 8 and 9, wherein the apparatus is a coin telephone. INTERNATIONAL STANDARD ELECTRIC CORPORATION P.M. Conrick Authorized Agent 5/1/1223 NEW ZEALAND f / JAM "°85 patent ofpic - 9 -