IE50103B1 - Telephone handset - Google Patents

Abstract

A telephone handset has a handle portion formed with at least one aperture 3 extending therethrough. It is preferably of two-part construction, having a base part 1 and a cover part 2. The base part 1 is provided with recesses 6 and 7 for accommodating receiving and transmitting acoustic transducers. Advantageously, the handle portion comprises two tubular side portions 10, 100 and 11, 110. The aperture 3 reduces acoustic feedback between transducers in the recesses 6 and 7.

Description

This invention relates to telephone handsets.

It is known to provide a telephone handset, comprising a hollow body of thermoplastic plastics material. The body is provided at opposite ends with recesses respectively for accommodating receiving and transmitting acoustic transducers. A handle portion extends between the recesses at the ends of the body, and affords a hollow passage for connecting wires for the transducers, for example.

Due to the construction of the known handset, acoustic feedback (whistling) can occur when the handset is operational, for example, if the handset is placed on a table-top. This produces an acoustic bridge. To overcome this, various different measures have been proposed. For example, vibration-damping inserts have been provided for the acoustic transducers, or a closed hollow cavity has been provided behind the transmitting transducer, to damp vibration.

U.S. Patent Specification 2 190 467 discloses a telephone handset having a solid handle, at .opposite ends of which are provided recesses for accommodating acoustic transducers. The transducers are secured to-the handle by moulded parts, which are preferably provided with a thread. The handle of the handset contains chambers having apertures, and there is disclosed a mathematical relationship between the volume d£ the chambers and acoustic feedback.

German Patent Specification 24 53 185 discloses an arrangement for reduding acoustic feedback in telephone handsets, in which the surface area of one of the parts of a handset is mechanically increased between receiving and transmitting transducers, such that the sound waves which excite feedback are reflected, with the effect that they tend to become absorbed and/or their intensity is reduced, by dispersion. Whilst there may be obtained a reduction in the tendency for feedback to occur, we have nevertheless found that, if such a handset is momentarily placed on a smooth surface, such as a table-top, then acoustic feedback may still occur.

One object of the present invention is to provide, in preferred embodiments, a simple and effective means for reducing acoustic feedback in the telephone handset.

More generally, according to the present invention there is provided a telephone handset comprising a body which is formed with respective recesses for accommodating transmitting and receiving acoustic transducers, and has a handle portion extending between said recesses, the handle portion being formed with at least one aperture passing therethrough.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawing, in which: Figure 1 is a side view of a telephone handset; Figure 2 is a top plan view of the handset; and Figure 3 is a bottom plan view of the handset.

The illustrated telephone handset comprises a §0103 body which is composed of a base part 1 and a cover part 2. The figures do not show the operative parts of the handset, such as the transmitting and receiving acoustic transducers, and their connections, as these are not essential to an understanding of the invention.

The base part 1 of the handset is provided at one end with a recess 6 for accommodating a receiving acoustic transducer, and at an opposite end with a recess 7 for accommodating a transmitting acoustic transducer. In the region of the recess 7, the base part 1 is also formed with an opening 8 which serves to accommodate a connecting cord 9 for the handset.

The base part 1 and cover part 2 of the handset meet along a joining edge 12. They may be connected together in an interlocking manner, and/or may be provided with securing means such as screw-fittings for positive interengagement. The cover part 2 is provided with recessed portions 13 and 131 which serve to cover the recess 7 and 6 respectively.

Between the recesses 6 and 7, the telephone handset has a handle portion comprising two substantially parallel side portions which define therebetween a relatively large aperture 3. The aperture 3 gasses completely through the handle portion of the telephone handset. The afore25 mentioned side portions are each of tubular cross-section, and respectively comprise a semi-tubular portion 10 or 11 on the cover part 2, and a mating semi-tubular portion 100 or 110 on the base part 2. The side portions 10, 100 and 11, 110 may have any cross-section, for example, round or. oval, although both side portions preferably have the same cross-sect ion.

It will be seen that, in the illustrated embodiment, the side portions 10, 100 and 11,110 extend from adjacent the recess 6 to adjacent the recess 7, the aperture 3 having a corresponding longitudinal extend. The lateral dimension of the aperture 3 is greater than the lateral dimension of each of the side portions 10,100 and 11,110 The construction of the illustrated telephone handset , having a relatively large aperture 3 between the two tubular side portions 10, 100 and 11, 110,tends to prevent acoustic feedback between the transducers in the recesses 6 and 7, such that any tendency for whistling is substantially prevented.

Also, the construction of the handset facilitates manipulation by hands of varying size, Referring to Figure 1, it can be seen that the body of the telephone handset has a generally curved shape, such that its opposite ends define angles 4 and 5 with respect to.a straight line 14. The angles 4 and 5 are selected in accordance with ergonomic requirements.

Although the illustrated embodiment is expeditiously provided with a single relatively large aperture 3, it is conceivable that the aperture 3:.-jnay be sub-divided into a plurality of apertures, for example, by transverse struts between the side portions 10, 100 and 11,110. Such apertures may be of rounded shape, such as circular or oval, rather than the rectangular shape as illustrated.

Claims (14)

1. A telephone handset comprising a .body which is formed with respective recesses for accommodating transmitting and receiving acoustic transducers, and has a handle portion 5 extending between said recesses, the handle portion being formed with at least one aperture passing therethrough.

2. A handset according to claim 1, wherein the body is of two-part construction, having a base part formed with said recesses, and a cover part which is secured 10 to said base part to cover said recesses.

3. A handset according to claim 1 or 2, wherein said body is substantially hollow.

4. A handset according to claim 2 or 3, wherein said base part is formed with means for accommodating a 15 connecting cord.

5. A handset according to claim 1, wherein said body has a generally curved shape.

6. A handset according to any preceding claim, wherein said handle portion comprises two substantially 20 parallel side portions between which said aperture is defined.

7. A handset according to claims 2 and 6, wherein said side portions are each partially defined by said Hase part and cover part 25

8. A handset according to claim 6 or 7, wherein the lateral dimension of said aperture is greater than the lateral dimension of each of said side portions. 50 103

9. A handset according to claim 6, 7 or 8, wherein said side portions, and thereby said aperture, extend from adjacent one to adjacent the other of said retesses.

10. A handset according to claim 6, 7, 8 or 9, 5 wherein said side portions are tubular.

11. A handset according to any one of claims 6 to 10, wherein said side portions have similar cross-sections.

12. A handset according to any one of claims 6 to 11, wherein said side portions are of circular or oval cross10 section.

13. A telephone handset substantially as hereinbefore described with reference to the accompanying drawing.

14. A telephone provided with a handset according to any preceding claim.