GB2085230A

GB2085230A - Pushbutton keyboard

Info

Publication number: GB2085230A
Application number: GB8126174A
Authority: GB
Original assignee: International Standard Electric Corp
Current assignee: International Standard Electric Corp
Priority date: 1980-10-07
Filing date: 1981-08-27
Publication date: 1982-04-21
Also published as: AU7596781A; GB2085230B

Abstract

A pushbutton keyboard, for use as a telephone keyblock, has an array of flexible cantilever actuating arms (4) with associated push button switch assemblies (7) each arranged below one of the arms (4). Each arm (4) has a contoured pushbutton (6) at its free end, so that depressing one of the buttons operates the switch assembly under the arm on which that button is mounted. On release of the button (6), the arm's resilience returns the button to its rest condition. Each button (6) is of translucent material, with an LED (9) below it to indicate circuit condition. The actuating arms (4) are integral with a plastics sheet which is mounted together with the switch assemblies (7) on a printed circuit board (1). <IMAGE>

Description

SPECIFICATION Pushbutton keyboard This invention relates to a pushbutton keyboard arrangement particularly though not exclusively for a telephone subset incorporating a key signalling means.

Known keyboard arrangements incorporate relatively complicated switch assemblies having expensive components, and it is an object of this invention to provide a simple pushbutton keyboard arrangement which may be adapted to incorporate various inexpensive pushbutton switch assemblies.

Accordingly, there is provided a pushbutton keyboard arrangement including a support member having a generally planar surface upon which is mounted a plurality of pushbutton switch assemb iies, and an array of flexible cantilever actuating arms each extending from a support point mounted upon the support member, wherein part of each actuating arm is positioned over an associated pushbutton switch assembly and so arranged that upon selective displacement of an actuating arm, actuating means of the associated pushbutton switch assembly is pushed thereby to operate the pushbutton switch assembly.

Preferably the free end of each cantilever arm terminates in a contoured key button. The key button at least may be formed from a translucent material and suitable light source means such as, for example, a light emitting diode arranged beneath the key button to visualiy indicate a particular circuit condition upon operation of an associated switch assembly.

An embodiment of the invention will now be described in which: Figure 1 is a top plan view of a keyboard assembly embodying the invention, showing an array of ten actuating arms, and Figure 2 is a section along 2-2 of Figure 1 showing the arrangement of lamp signalling means and snap-acting pushbutton switch assemblies associated with two actuating arms.

Referring to Figures 1 and 2 the assembly includes a rectangular printed circuit board 1 measuring approximately 108 mm x 87 mm x 2 mm upon which is disposed a number of conductive paths arranged in a predetermined pattern (not shown). An array 2 of ten substantially flat flexible actuating arms formed from a single sheet of translucent polycarbonate plastics material is mounted substantially conterminously above the printed circuit board 1 on a support member 3 which extends the full width of the array 2. The support member 3 provides a point of support for the ten cantilever actuating arms 4. Each of these arms terminates at its free end in a contoured hollow key-button 6. Figure 2 shows two of ten snap-acting push-button switch assemblies 7 whose terminals (not shown) extend through printed circuit board 1 and are soldered to the conductive paths arranged thereon.Switch actuating button 8, telescopically mounted in the body of the pushbutton switch assembly 7, is positioned beneath part of the actuating arm 4 at such a distance that upon depression of keybutton 6 and the consequent displacement of the actuating arm 4, it is pushed down until the snap mechanism (not shown) operates and renders the switch assembly 7 operative. The resilience of the arm 4 causes it to return to its normal unstressed position after pressure is removed from keybutton 6. Light emitting diodes 9 are mounted on the printed circuit board 1 beneath each keybutton 6. The terminals thereof (not shown) extend through the printed circuit board 1 and are soldered to the conductive paths arranged on the printed circuit board.

It will be understood that the pushbutton keyboard arrangement of the present invention can be adapted to accomodate various types of pushbutton switch assemblies. For example, the snap acting push-button switch assemblies may be replaced by an array of switches comprising a sheet of elastic resilient material having conductive pads arranged thereon which are brought into contact with associated switch elements upon depression of the sheet.

In use the keyboard arrangement of the present invention may be mounted on the telephone subset baseplate with keybuttons 6 arranged to protrude through apertures provided in the subset housing.

The arrangement described above is for a 5 x 2 array of pushbuttons, but it will be appreciated that the invention is equally applicable to other forms of array. One such form of array which is of great contemporary interest is the 4 x 3 array rapidly becoming standard for telephone use. To adapt the present invention to this would be relatively easy since each 4 x 3 array could be formed by two 3 x 2 arrays. Each such array is then in effectthe two three rows of Figure 1, the two such arrays being mounted in end-on relation.

1. A pushbutton keyboard arrangement including a support member having a generally planar surface upon which is mounted a plurality of pushbutton switch assemblies, and an array of flexible cantilever actuating arms each extending from a support point mounted on the support member, wherein part of each actuating arm is positioned over an associated pushbutton switch assembly and so arranged that upon selective displacement of an actuating arm, actuating means of the associated pushbutton switch assembly is pushed thereby to operate the pushbutton switch assembly.

2. An arrangement as claimed in claim 1, and in which the switch assemblies are arranged on m x n array where m is an even number, the support points for the cantilever arms being provided by a ridge on the support member located centrally with respect to the arms.

3. An arrangement as claimed in claim 1 or 2, and in which the free end of each said cantilever arm terminates in pushbutton means.

4. An arrangement as claimed in claim 3, and in which each said pushbutton is of translucent material, with a light source such as a light-emitting diode below the buttons to usually indicate when the button is operated.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Pushbutton keyboard This invention relates to a pushbutton keyboard arrangement particularly though not exclusively for a telephone subset incorporating a key signalling means. Known keyboard arrangements incorporate relatively complicated switch assemblies having expensive components, and it is an object of this invention to provide a simple pushbutton keyboard arrangement which may be adapted to incorporate various inexpensive pushbutton switch assemblies. Accordingly, there is provided a pushbutton keyboard arrangement including a support member having a generally planar surface upon which is mounted a plurality of pushbutton switch assemb iies, and an array of flexible cantilever actuating arms each extending from a support point mounted upon the support member, wherein part of each actuating arm is positioned over an associated pushbutton switch assembly and so arranged that upon selective displacement of an actuating arm, actuating means of the associated pushbutton switch assembly is pushed thereby to operate the pushbutton switch assembly. Preferably the free end of each cantilever arm terminates in a contoured key button. The key button at least may be formed from a translucent material and suitable light source means such as, for example, a light emitting diode arranged beneath the key button to visualiy indicate a particular circuit condition upon operation of an associated switch assembly. An embodiment of the invention will now be described in which: Figure 1 is a top plan view of a keyboard assembly embodying the invention, showing an array of ten actuating arms, and Figure 2 is a section along 2-2 of Figure 1 showing the arrangement of lamp signalling means and snap-acting pushbutton switch assemblies associated with two actuating arms. Referring to Figures 1 and 2 the assembly includes a rectangular printed circuit board 1 measuring approximately 108 mm x 87 mm x 2 mm upon which is disposed a number of conductive paths arranged in a predetermined pattern (not shown). An array 2 of ten substantially flat flexible actuating arms formed from a single sheet of translucent polycarbonate plastics material is mounted substantially conterminously above the printed circuit board 1 on a support member 3 which extends the full width of the array 2. The support member 3 provides a point of support for the ten cantilever actuating arms 4. Each of these arms terminates at its free end in a contoured hollow key-button 6. Figure 2 shows two of ten snap-acting push-button switch assemblies 7 whose terminals (not shown) extend through printed circuit board 1 and are soldered to the conductive paths arranged thereon.Switch actuating button 8, telescopically mounted in the body of the pushbutton switch assembly 7, is positioned beneath part of the actuating arm 4 at such a distance that upon depression of keybutton 6 and the consequent displacement of the actuating arm 4, it is pushed down until the snap mechanism (not shown) operates and renders the switch assembly 7 operative. The resilience of the arm 4 causes it to return to its normal unstressed position after pressure is removed from keybutton 6. Light emitting diodes 9 are mounted on the printed circuit board 1 beneath each keybutton 6. The terminals thereof (not shown) extend through the printed circuit board 1 and are soldered to the conductive paths arranged on the printed circuit board. It will be understood that the pushbutton keyboard arrangement of the present invention can be adapted to accomodate various types of pushbutton switch assemblies. For example, the snap acting push-button switch assemblies may be replaced by an array of switches comprising a sheet of elastic resilient material having conductive pads arranged thereon which are brought into contact with associated switch elements upon depression of the sheet. In use the keyboard arrangement of the present invention may be mounted on the telephone subset baseplate with keybuttons 6 arranged to protrude through apertures provided in the subset housing. The arrangement described above is for a 5 x 2 array of pushbuttons, but it will be appreciated that the invention is equally applicable to other forms of array. One such form of array which is of great contemporary interest is the 4 x 3 array rapidly becoming standard for telephone use. To adapt the present invention to this would be relatively easy since each 4 x 3 array could be formed by two 3 x 2 arrays. Each such array is then in effectthe two three rows of Figure 1, the two such arrays being mounted in end-on relation. CLAIMS

5. An arrangement as claimed in claim 1, 2,3 or 4, and in which all of said arms are integrally formed from a sheet of a suitably resilient material.

6. An arrangement as claimed in any one of the preceding claims, and in which said cantilever actuating arms are formed from polycarbonate plastics material.

7. An arrangement as claimed in any one of the preceding claims, and in which said support mem bercomprises a printed circuit board having conductive circuit paths to at least some of which are connected in a predetermined manner said pushbutton switch assemblies.

8. An arrangement as claimed in claim 7 as appended to claim 5 or 6, and in which said lamp means are connected to conductive paths of said printed circuit boards.

9. An arrangement as claimed in any one of the preceding claims, and in which said array of flexible cantilever actuating arms is an integral construction.

10. An arrangement as claimed in any one of the preceding claims, and in which said support point and array of flexible cantilever actuating arms are of an integral construction.

11. An arrangement as claimed in any one of the preceding claims, and in which said actuating arms extend substantially perpendicular from the support point.

12. An arrangement as claimed in any one of the preceding claims, and in which the said array is symmetrical in relation to the longitudinal axis of the support point.

13. An arrangement as claimed in claim 2 or any claim subordinate thereto, and in which the arrangemet is a 4 x 3 array formed by two adjacently located 3 x 2 arrays.

14. An arrangement as claimed in claim 2 or any claim subordinate thereto, and in which the arrangement is a 5 x 2 array.

15. A pushbutton keyboard arrangement substantially as described with reference to the accompanying drawings.

New claims or amendments to claims filed on 19 January 1982 Superseded claims None New claims:

16. A pushbutton keyboard arrangement including a support member having a generally planar sun'ace open which is mounted a plurality of pushbutton switch assemblies, and an array of flexible cantilever actuating arms each extending from a support point mounted on the support member, and a manually-operable pushbutton at the free end of each said cantilever arm, wherein part of each actuating arm which is between its support point and its free end is positioned over an associated pushbutton switch assembly, the arrangement being such that upon selective displacement of an actuating arm, the actuating means of the associated pushbutton switch assembly is pushed thereby to operate the pushbutton switch assembly, the location of each said switch assembly providing a mechanical advantage for pushbutton operation.

17. An arrangement as claimed in claim 16, and in which the switch assemblies are arranged on m x n array where m is an even number, the support points for the cantilever arms being provided by a ridge on the support member located centrally with respect to the arms, and the arms extending substantially parallel to each other.

18. An arrangement as claimed in claim 16 or 17, and in which each said pushbutton is of translucent material, with a light source such as a light-emitting diode below the buttons to usually indicate when the button is operated.