GB2064221A - Digit sending electric switch for telephone use - Google Patents

Abstract

A single-button telephone "dialler" has a central rod-like member (6, 10, 4) with a button 1 on its upper-most end and a lower portion of springy wire 6, and is surrounded by a set of contact pairs (8), engageable by a portion of insulating material (10) for contact operation. Also surrounding the rod there is a locating member 3 with a set of slots 9 radially arranged and each associated with one contact pair. To send a digit the rod is moved sideways into the slot for the digit to be sent until it operates the contact pair (8) to cause digit sending. When the rod is released, the springiness of the wire (6) returns it to rest. In a simplified version the rod also acts as a contact and is mainly of metal to co-operate with single contacts each at the end of one of the slots. <IMAGE>

Description

SPECIFICATION Digit sending apparatus for telephone use This invention relates to a digit transmitting arrangement, usable, for instance, for transmitting wanted subscriber numbers in a telephone exchange system.

In such systems the commonest arrangement for sending the digits of the numbers is the wellknown dial, which is a relatively complicated mechanical contrivance. Also much used are push-button sets, which are also relatively complex.

An object of this invention is to provide a digit transmitting arrangement which is relatively simple and inexpensive.

According to the invention there is provided a digit-transmitting arrangement, which includes a central rod-like member surrounded by a number of contact means, each said contact means corresponding to a digit to be transmitted, the operation of a said contact means causing the transmission of signals representative of the digit to which that contact means corresponds, and guide means associated with each of said contact means, wherein to cause transmission of one of said digits the rod-like member is moved sideways from its central position into the guide means appropriate to the digit to be sent so as to operate the contact means therefor to cause said transmission of signals appropriate to that digit, whereafter the rod-like member is returned to its central position.

Emboiments of the invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a digit transmitting arrangement for a telephone with its cover and push-button removed, which embodies the invention.

Fig. 2 is a cross-section of the arrangement of Fig. 1.

Fig. 3 is a view similar to Fig. 1, but with the cover in place.

Fig. 4 and Fig. 5 show schematically an arrangement such as that in Figs. 1 to 3 in place in a telephone housing.

Figs. 6 and 7 sideviews, partly sectionalised, and a view from above, of an alpha-numeric keyboard in which three digit transmitters, each substantially similar to the arrangement of Figs. 1,.

2 and 3, are used.

Fig. 8 is a cheap version of the transmitting arrangement of Figs. 1, 2 and 3.

In Figs. 1 to 3, the arrangement has a concave push-button 1 formed intergral with a domeshaped shroud 2, the shroud fitting over a locating dome 3. This button is connected by a locating pin 4 to a contact actuator 5 which is circular in crosssection. At its lower end the actuator 5 is coupled by a spring wire 6 to a printed circuit board 7 which forms the base of the arrangement.

Mounted on the board 7 there are a number of contact spring sets such as 8, the individual springs being leaf springs. These are distributed about the button 1 and its associated components, each in a position appropriate to one of a number of digital values. The locating dome 3, as can be seen from Fig. 1, has a number of slots such as 9 each aligned with one of the contact sets 8, and each slot having a widened throat to faciiitate the entry into it of the locating pin 4 of the push-button 1.

The whole arrangement is within a cover 10 which, as shown in Fig. 3 is marked with the designation of the various digital values. In addition, the button's shroud 2 has black lines on its upper surface each radially aligned with one of the contact set positions. Fig. 1 shows at 11 the location of one of the contact sets.

To send a digit, the user pushes the button sideways in the direction of the digit to be sent, being guided in this respect byone of the lines on the shroud. During this movement the locating pin 4 enters the slot 9 for the "wanted" digit, and the user pushes the button as far as it will go. This operates the appropriate contact set by the action of the contact actuator 5. When the user releases the button 1, it snaps back, with the shroud, to the central position as shown in Fig. 2.

The dome shaped shroud hides the locating grooves from view, and protects the contacts from spilt liquids, tobacco ash, etc.

The base 7 referred to above is a printed circuit board having on its surface printed conductive tracks extending from the contact sets to connection 11 on the edge of the board. These give access, e.g. via an edge connector, to circuitry for generating electrical signals to be sent to iine, or optical signals if the telephone is connected to the exchange by an optical fibre link.

Note that, unlike a dial, the rate of returns of the user-operated member has no effect on the signals as sent. Further, the time taken to send a digit is the same whatever its value, which is useful for sending a code like 999.

Figs. 4 and 5 show how an arrangement such as that of Figs. 1 to 3 wouid look when used in the body of a telephone of the type sold under the trade mark TRIMPHONE. If desired, the arrangement can be made small enough for two to be built into a telephone body, one for number sending and the other for the provision of service facilities.

In the alphanumeric keyboard, Fig. 7, three digit senders are used, each of which could have a diameter of the order of one inch. In this case the concave button used in Figs. 1-3 is replaced by a waisted portion for gripping between finger and thumb. Movement to send a digit in this device is about one quarter of an inch. Such a scaled down version could also be built into a telephone handset without needing the widened portion required when dials or push-button sets are used.

The keyboard of Fig. 7, as mentioned, has three one-button senders marked as shown. X and Z being the least-used letters are put on the numeric sender. Thus a small visual display unit with its display 20 can be provided without needing the relatively large conventional keyboard. Such an arrangement can be used to control an "intelligent" telephone terminal.

Where an extra range is needed, e.g. as for upper and lower case, a button can be added to make the change. Another way is to give the sending arrangement double touch, i.e. the change is effected by using extra pressure on the button.

A pair of contacts below the board 7 could respond to such extra pressure.

If confirmatory feedback is needed it can be provided audibly or visually by suitable circuitry, Fig. 8 is a simplified low cost arrangement which uses the same principles as does the arrangement of Figs. 1 to 3. This is mounted to a panel 21 with a locating plate 22 mounted below it. This panel 21 has locating slots, indicated schematically at 23 for guiding the locating pin portion 24 of the operating rod 25. This upper end has a knurled end portion to be gripped by the user. Designations for the digits are printed on the outer face of the panel.

Below the plate 22 there is a printed circuit board 26 separated from the plate by spacers 27 formed integral with the plate 22. Below the board 26 there is a moulded frame 28 the lower portion of which supports the lower end of the operating rod. This has a spring wire portion 30. The lower end of this wire 30, as indicated at 31, forms an electrical connection, and each operation of the rod 25 into a slot completes a connection to contacts on the board 26, as indicated at 32.

Electronic circuitry responds to the contact with or proximity to the board by the rod to cause digit sending.

Claims (10)

1. A digit-transmitting arrangement, which includes a central rod-like member surrounded by a number of contact means, each said contact means corresponding to a digit to be transmitted, the operation of a said contact means causing the transmission of signals representative of the digit to which that contact means corresponds, and guide means associated with each of said contact means, wherein to cause transmission of one of said digits the rod-like member is moved sideways from its central position into the guide means appropriate to the digit to be sent so as to operate the contact means therefor to cause said transmission of signals appropriate to that digit, whereafter the rod-like member is returned to its central position.

2. An arrangement as claimed in claim 1, and wherein part at least of the rod-like member is a springy wire, so that when the rod-like member is released after having been moved into a said guide means it is reset to its central position by the resilience of the springy wire.

3. An arrangement as claimed in claim 1 or 2, and wherein each said guide means is one of a number of radially-arranged slots in a locating member surrounding the rod-like member, each said slot having a widened throat to receive the rod-like member.

4. An arrangement as claimed in claim 3, wherein the locating member is a dome-shaped member enclosing the contact means, and wherein the rod-like member has a curved shroud outside and parallel to the dome-shaped member with a push-button or finger grip outside the shroud.

5. An arrangement as claimed in claim 4, wherein each of the contact means is an upstanding pair of contacts mounted on a base plate, the said pairs of contacts being located in a circle around the rod-like means, and wherein the rod-like means consists of said springy wire anchored to the base plate, a portion of insulating material for contact operation, and a pin-like portion adapted to enter any one of the slots.

6. An arrangement as claimed in claim 2, wherein each said guide means is one of a number of radially arranged slots in a locating plate through the centre of which the rod-like member passes, and wherein said contact means includes said rod-like member and a contact at the base of each said slot, so that each said contact means is formed by the rod-like member and one of said contacts.

7. A digit-transmitting arrangement substantially as described with reference to Figs, 1 to 3 of the accompanying drawings.

8. A digit transmitting arrangement substantially as described with reference to Fig. 8 of the accompanying drawings.

9. A telephone instrument in which digit sending is effected by one or more arrangements each as claimed in any one of claims 1 to 8.

10. A digit-transmitting keyboard in which digits are sent by one or more arrangements each as claimed in any one of claims 1 to 8.