GB2242099A

GB2242099A - Auxiliary telephone receiver unit

Info

Publication number: GB2242099A
Application number: GB9105443A
Authority: GB
Inventors: David Valentine Charlesworth
Original assignee: Hosiden Besson Ltd
Current assignee: Hosiden Besson Ltd
Priority date: 1990-03-14
Filing date: 1991-03-14
Publication date: 1991-09-18
Anticipated expiration: 2011-03-14
Also published as: GB2242099B; GB9105443D0; GB9005740D0

Abstract

An auxiliary telephone receiver unit operates in conjunction with a telephone instrument to enable a second person to listen-in when a first person uses the instrument. The unit comprises a housing (1) of two parts (1A, 1B) secured together and has a wall (3) with apertures (4) in it such that the external surface (3A) can be held against the second person's ear. Receiver (6) is mounted inside the housing over the apertures (4) and connected to a first end of a cable (17) through a push-button switch (14, 15). Diodes (13) may be connected across the receiver (6) to provide acoustic shock protection to the said second person. A standard plug (18) connected to a second end of the cable (17) plugs into a parallel-connected double socket provided on a telephone line. Coupling to a hearing aid may be provided by a hearing aid compatible receiver which incorporates an internal coil for this purpose. <IMAGE>

Description

AUXILIARY TffiRPEONE RECEIVER UNIT This invention concerns an auxiliary telephone receiver unit which is adapted to be readily connected to a telephone line in parallel with a telephone instrument.

By means of such a unit, a user thereof is conveniently enabled to listen-in to conversation between a person using the telephone instrument and another person at a remote telephone instrument.

The present invention provides an auxiliary telephone receiver unit for use in conjunction with a telephone instrument to enable a second person to listenin to conversation when a first person uses said instrument, said auxiliary telephone receiver unit comprising: a housing having an apertured wall with an external surface adapted to be held against an ear of a user; a receiver capsule mounted within the housing against an internal surface of said apertured wall; electric cable means extending from said housing and having a first end connected to the receiver capsule and a second end adapted to be connected to a telephone line in parallel with the said telephone instrument.

The said telephone line is conveniently provided with double connector means adapted and arranged to receive a first plug means connected to an electric cable from the said telephone instrument and a second plug means connected to the second end of the said cable means extending from the housing of the auxiliary telephone receiver unit.

The double connector means may either comprise a double line jack socket arrangement or a single line jack socket provided with a double outlet adaptor plugged therein.

Switch means, suitably of push-button form, may be provided incorporated in said housing and interconnected with the receiver capsule and the first end of the cable means and operable by the said second person when listening-in is required.

An electric amplifier is preferably provided in the housing and electrically connected between the receiver capsule and the first end of the cable means. The receiver capsule may be a hearing aid of compatible type.

One or more diodes 'is or are preferably provided in the housing and electrically connected in parallel with the receiver capsule, whereby acoustic shock protection is provided to the said second person when using the receiver unit.

The auxiliary receiver unit is suitably adapted and arranged to be electrically connected to the telephone line in such a way as to be capable of receiving speech issuing from and being received by the telephone instrument.

The said housing is suitably formed of two parts, e.g. of plastics material, or metal, secured together.

The invention is now described by way of example with reference to the accompanying drawings, in which: Fig. 1 represents a perspective view of an auxiliary telephone receiver unit according to the invention; Fig. 2 represents a cross-sectional view of the receiver unit of Fig. 1; Fig. 3 represents a circuit diagram of the receiver unit of Fig. 1; and Fig. 4 is a more detailed circuit diagram of the circuit shown in Fig. 3.

An auxiliary telephone receiver unit is constructed as follows. A housing 1 is formed of two parts 1A and 1B arranged to be secured together by interlocking portions 2A and 2B (Fig. 2). The two parts of the housing suitably comprise a plastics material and are conveniently formed by a process such as injection moulding. The part 1A of the housing has a wall 3 with apertures 4 through it, the wall 3 having an external surface 3A appropriately contoured such that it can be manually held against an ear of a person using it. The part 1B of the housing has contoured portions 5 to facilitate holding by a user. A receiver capsule 6 is secured in the housing 1 against internal surface 3B of the wall 3.An upstanding wall member 7 is provided in the part 1A of the housing and surrounding the receiver capsule 6 to enable speech received by the receiver unit to be transmitted to a hearing aid (not shown).

A printed circuit board 10 is mounted at the back of the receiver capsule 6 and carries an amplifier 11 as indicated in the circuit diagram of Fig. 3. The printed circuit board 10 also carries a simple spring switch 14 which is contactable by a push-button means 15 located in an aperture through the part 1B of the housing.

Alternatively the switch may be of a microswitch type.

The components on the circuit board 10 are interconnected as shown in Fig. 3 which also shows connection terminals of an electric cable 17.

An electric cable 17 is provided extending through an aperture in the housing 1. Cable 17 is connected at one end inside the housing 1 to the circuit board 10 and hence via the amplifier 11 and push-button switch 14, 15 to the terminals 16 of the receiver capsule 6.

A remote end of the cable 17 is provided with a standard plug 18 (Fig.l) which fits into a standard jack socket (not shown) connected to a telephone line. A well known form of double connector is required to be utilised at the line jack socket to enable a plug from a standard telephone instrument to be connected to the socket in addition to and in parallel with the plug 18. Referring again to Fig. 3, diodes are connected in parallel with the receiver capsule 6 to provide acoustic shock protection to a user of the receiver unit.

In the more detailed circuit diagram shown in Fig.

4, the power is supplied via terminals and electric cable 17 to a push-button switch 14, 15 to a bridge rectifier 18 so that the circuit operates on either polarity. The power is fed to an amplifier 11 via the bridge derived from the telephone line via electric cable 17. A coupling capacitor 19 is provided for signal feed to amplifier 11 and a second coupling capacitor 20 is located between the output of the amplifier and receiver to block D.C. to the receiver and to limit the low frequency response. A resistor 21 sets the gain of the amplifier 11 in the negative feedback path. The amplifier 11 may be constructed from discrete components or be of the integrated circuit type.

In operation, when a person is making a telephone call on a telephone instrument which is connected to a telephone line jack socket in parallel with the auxiliary receiver unit of the invention, a second person is able to listen-in to conversations issuing from and received by the telephone instrument by holding the auxiliary receiver unit to his or her ear and pushing the button 15 on it to activate the unit.

Claims

CLAIMS:

1. An auxiliary telephone receiver unit for use in conjunction with a telephone instrument to enable a second person to listen-in to conversations when a first person uses said instrument, said auxiliary telephone receiver unit comprising: a housing having an apertured wall with an external surface adapted to be held against an ear of a user; a receiver capsule mounted within the housing against an internal surface of said apertured wall; electric cable means extending from said housing and having a first end connected to the receiver capsule and a second end adapted to be connected to a telehone line in parallel with the said telephone instrument.

2. A receiver unit according to Claim 1, in which the said telephone line is provided with double connector means adapted and arranged to receive a first plug means connected to an electric cable from the said telephone instrument and a second plug means connected to the second end of the said cable means extending from the housing of the auxiliary telephone receiver unit.

3. A receiver unit according to Claim 1 or 2, in which switch means is provided incorporated in said housing and interconnected with the receiver capsule and the first end of the cable means and operable by the said second person when listening-in is required.

4. A receiver unit according to Claim 3, in which the switch means is of push button form.

5. A receiver unit according to any preceding claim, in which an electronic amplifier is provided in the housing and electrically connected between the receiver capsule and the first end of the cable means.

6. A receiver unit according to Claim 5, in which the receiver capsule is a hearing aid of compatible type.

7. A receiver unit according to any preceding claim, in which one or more diodes is or are provided in the housing and electrically connected in parallel with the receiver capsule.

8. A receiver unit according to any preceding claim, adapted and arranged to be electrically connected to the telephone line in such a way as to be capable of receiving speech issuing from and received by the telephone instrument.

9. A receiver unit according to any preceding claim, in which the said housing is formed of two parts, secured together.

10. A receiver unit according to Claim 9, in which the housing comprises plastics material and/or metal.

11. An auxiliary telephone receiver unit constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.