GB2191911A

GB2191911A - Telephone bell ringer

Info

Publication number: GB2191911A
Application number: GB08614948A
Authority: GB
Inventors: Richard Drewnicki
Original assignee: Talgold U K
Current assignee: Talgold U K
Priority date: 1986-06-19
Filing date: 1986-06-19
Publication date: 1987-12-23
Anticipated expiration: 2006-06-19
Also published as: GB8614948D0; GB2191911B

Abstract

An acoustic warning unit for use with a telephone system comprises an electrically operable acoustic transducer (20) connected across contacts 3 and 5 of a British Telecom plug (10) whereby on plugging into an extension socket of a telephone installation the transducer (20) will be energised on receipt of an incoming call and deenergised on lifting the receiver of a telephone in the system. <IMAGE>

Description

SPECIFICATION Telephone bell ringer This invention relates to an accessory for a telephone installation.

In a telephone installation it is customary for the telephone instrument to incorporate a solenoid operated bell or an electronic acoustic transducer connected such that on receipt of an incoming call the solenoid or transducer is energised to produce a ringing of the bell or an electronic tone from the transducer, and such that on lifting the telephone receiver the solenoid or transducer is deenergised.

It has also been known to provide bell or like installations for remote warning that a telephone requires operation but it has been necessary in the past for such installations to be made under the control of British Telecom or their predecessors the General Post Office Telecommunications Branch.

It is the object of the invention to provide an acoustic warning unit which may readily be connected into a standard British Telecom telephone socket, or the like, separately from or in addition to a telephone, so that a separate or remote warning can be provided.

An acoustic warning unit for use with a telephone system, according to the invention, comprises an electrically operable acoustic transducer having a pair of contacts across which the transducer may be energised, contacts of the pair being respectively connected to contacts 3 and 5 of a British Telecom plug or the like, whereby on plugging the plug into an extension socket of a telephone installation, the transducer will be energised on receipt of an incoming call and deenergised on lifting the receiver of a telephone in the system.

A standard plug is British Telecom part No, 431-A although like sockets of different size are used in other countries.

Suitably the transducer is connected to the plug by a flexible lead of extended length such that the unit may be arranged in a remote or selected position at the will of a user. Alternatively the plug may be secured to a housing containing the acoustic transducer, the assembly being mountable directly on the socket.

Whilst the plug may be used for connection into an existing extension socket, as a warning device for a telephone connected to a socket elsewhere in the system it may also be connected with the telephone to a common system socket by use of a splitter device comprising a standard plug portion having contacts 1 to 5 and a plurality of socket portions having contacts 1 to 5 connected to respective contacts 1-5 of the plug. Such splitter devices are available as British Telecom approved parts.

The transducer may be an electromechanical bell which generates an audible signal sound more acceptable to many users than other electrical or electronic transducers operating, for example, with diaphragm vibration.

The invention will now be described, by way of example, with reference to the partly diagrammatic drawings, in which: Figure 1 is an elevation of a solenoid operated bell connected to a BT plug; Figure 2 is a simple circuit diagram of the plug contact and bell connections; Figure 3 is a diagrammatic view of a standard splitter device, Figure 4 is a schematic circuit diagram of an improved embodiment including spurious signal isolation means; Figure 5 is a plan and underside view of a printed circuit board assembly including the isolation means for the circuit of Figure 4; Figure 6 is an assembled view of the printed circuit board of Figure 5 in the circuit of Figure 4 assembled with a bell structure and a telephone plug;; Figure 7 is a view similar to that of Figure 6 of a modified assembly, and Figure 8 is an underside perspective view of the assembly of Figure 7 mounted in a housing enclosure.

A standard telephone plug 10, British Telecom Part No. 431-A which is a releasable fit within a complementary telephone system socket, not shown, has contacts 1-5. A bell unit 20 comprising a solenoid operated mechanism and a bell of generally known construction has a solenoid connected across two terminals 30,40 to which are connected respective conductors 31,41, of a lead, and of which other ends are connected across contacts 3 and 5 of the plug 10.

The lead comprising the conductors 31,41 may be short or of extended length according to the flexibility of use intended.

In the splitter device 50 of Figure 3 comprises a plug portion 51 of Standard British Telecom form and two socket portions 52,53 of similar standard form, each having contacts 1-5 and respective contacts 1-5 of the portions 51,52 and 53 being commoned.

It will be readily appreciated that the plug portion 51 may be plugged into an existing telephone system outlet, not shown, and that a plug of a telephone, not shown, may be plugged into one of the socket portions 52,53 and the plug 10 of the ringing device in the other.

In an improved version the bell circuit includes isolation means 55 adapted to protect against spurious signals which might be developed when a telephone connected in the system is used to dial out via the telephone exchange. The means 55 suitably comprises a pair of Zener diodes, suitably 3.3 volts, connected in series in opposed fashion as shown in Figure 4. As shown in Figure 5 the Zener diodes are suitably mounted on a strip of printed circuit board 56 having the diodes 55 at one side connected to respective printed conductors on the other. The board 56 is mountable, as shown in Figure 6, within the bell 20 support structure with conductors leading from the bell solenoid connected to appropriate printed conductors on the board, and appropriate flexible conductors leading from the relevant printed conductors to the telephone plug 10. Alternatively the plug 10 may be secured to a lower side of the bell support structure, as shown in Figure 7 for direct mounting in and support of the assembly by a telephone socket.

The bell support structure is suitably contained within a housing closure 57, appropriately lowered to allow penetration of the audible warning and with the plug 10 projection from the underside thereof.

Claims

1. An acoustic warning unit for use with a telephone system comprising an electrically operable acoustic transducer having a pair of contacts across which the transducer may be energised, contacts of the pair being respectively connected to contacts 3 and 5 of a British Telecom telephone plug or the like, whereby on plugging the plug into an extension socket of a telephone installation, the transducer will be energised on receipt of an incoming call and also deenergised on lifting the receiver of a telephone in the system.

2. A warning unit as claimed in claim 1, in which the transducer is connected to the plug by an extended length of lead.

3. A warning unit as claimed in claim 2, in which the lead is flexible.

4. A warning unit as claimed in claim 1, in which the plug is secured to a housing containing the acoustic transducer.

5. A warning unit as claimed in any preceding claim in which isolation means are connected in the bell circuit adapted to protect against operation by spurious signals.

6. A warning unit as claimed in claim 5, in which the isolation unit comprises a pair of Zener diodes connected in series in opposed fashion.

7. A warning unit as claimed in claim 6, in which the Zener diodes are mounted on a printed circuit board mounted within a support structure for the transducer.

8. An acoustic warning unit arranged and adapted to operate substantially as described with reference to the accompanying drawings.