GB2160071A

GB2160071A - Telephone subset

Info

Publication number: GB2160071A
Application number: GB08512274A
Authority: GB
Inventors: Rainer Zimmermann
Original assignee: International Standard Electric Corp
Current assignee: International Standard Electric Corp
Priority date: 1984-05-26
Filing date: 1985-05-15
Publication date: 1985-12-11
Also published as: DE3419825A1; GB2160071B; GB8512274D0

Abstract

Into a cutout of the housing (1) of a telephone subset there is inserted a control knob (2) which consists of a disc with a tubular, slotted projection (6). In the disc there is provided a sound channel (3) which widens in a helical manner, and which leads to a sound space (8) lying therebelow and which surrounds the projection (6) and is formed by a funnel-shaped recessed plate (7). The projection (6) is placed on to the sound-exit flange (9) of the signal generator transducer (4). <IMAGE>

Description

SPECIFICATION Telephone subset This invention relates to a telephone subset of the kind having a housing containing a sound radiation outlet, and comprising an electro-acoustic transducer serving as the signal generator inside the housing, a sound-conducting space between the signal generator and the sound-radiation outlet, and a control knob for regulating the volume of the signal generator which is connected to a potentiometer.

One such telephone subset is known, for example, from DE-GM 79 10 907. In this subset, the tone ringer is accommodated on a special supporting member on which there is not only disposed the signal generator, but also the sound-conducting elements and the control knob for regulating the volume, and which is intended to serve as a compact subassembly group for replacing the conventional telephone ringer. The entire subassembly group is capable of being inserted in such a way into the set, that the sound funnel is acoustically decoupled from the interior space of the subset.

The control knob partially protudes from the housing of the subset and is provided with a knurl for facilitating the operation thereof. Via a shaft, the control knob is connected to a potentiometer which, together with other electric components, is mounted on a printed circuit board. With the aid thereof, the volume of the tone ringer signal can be varied. Moreover, a further adjusting device is accommodated in the subassembly group.

It is an object of the invention, with reference to a telephone subset of the kind referred to, to integrate the control knob for regulating the volume of the tone ringer in such a way into one wall of the housing of the subset, that it is flush with the top surface and yet easy to operate, the control knob being capable at the same time of serving as the sound radiation outlet, so that special sound apertures in the housing of the set may be omitted.

According to the invention in its broadest aspect, a telephone subset of the kind referred to is characterised in that the control knob comprises a disc having a concentric, tubular projection provided with openings, along the circumference of which there is a sound channel widening in a helical manner, for serving as the sound radiation outlet, and opening up into the sound-conducting space, which surrounds the projection placed onto the sound outlet flange of the signal generator.

The advantage of this construction resides in the simple, elegant connection between the control knob and the sound aperture, with the knob itself being completely integrated into the surface of the telephone set, while the sound aperture has in such a way become part of the control knob that the position of the control knob is simultaneously indicative of the volume to which the tone ringer has been adjusted.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows the volume control device according to the invention, for the tone ringer of a telephone subset in a top view, and Figure 2 is a cross sectional view taken through the control device as shown in Figure 1.

In the drawings, the housing of the telephone subset is indicated by the reference numeral 1. Into a circular cutout of one wall of the housing there is let a control knob 2 which, along its circumference, comprises a sound channel 3 extending over about 270 and which continuously becomes wider in that its inward edge follows the shape of a helix.

The control knob 2 consists of a disc having a tubular, concentrical projection 6 directed toward the interior of the telphone set (Figure 2). This projection 6 traverses a plate 7 which, within the area below the disc of the control knob 2, comprises a funnel-shaped recess 14, so that a sound-conducting space 8 is created between the control knob 2 and the recess 14.

Partly into the projection 6 of the control knob 2, there protrudes the tubular flange 9 of an electroacoustic transducer element serving as the signal generator 4, and which forms the sound exit thereof. The projection 6 is provided with openings, such as slots 10, thus permitting the sound to propagate from the projection 6 into the space 8 and from there through the sound channel 3 of the control knob towards the outside.

The helical shape of the sound channel 3 simultaneously also serves to indicate the adjusted sound intensity which can be regulated via the volume control knob 2 and which is indicated by a marking 11 on the housing (Figure 1). Adjustment of the sound volume (intensity) is effected electrically by means of a potentiometer 12 which is mounted below the signal generator 4 on a printed circuit board 13 on which the oscillator and other componets of the telephone subset (not shown) are also accommodated.

1. A telephone subset of the kind having a housing containing a sound radiation outlet, and comprising an electro-acoustic transducer serving as the signal generator inside the housing, a sound-conducting space between the signal generator and the sound-radiation outlet, and a control knob for regulating the volume of the signal generator which is connected to a potentiometer, characterised in that the control knob (2) comprises a disc having a concentric, tubular projection (6) provided with openings, along the circumference of which there is provided a sound channel (3) widening in a helical manner, for serving as the sound radiation outlet, and opening up into the soundconducting space (8), which surrounds the projection (6) placed onto the sound outlet flange (9) of the signal generator (4).

2. A telephone subset as claimed in claim 1, characterised in that between the control knob (2) and the signal generator (4) there is inserted a plate (7) which is provided, below the control knob, with a funnel-shaped recess (14) forming the

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Telephone subset This invention relates to a telephone subset of the kind having a housing containing a sound radiation outlet, and comprising an electro-acoustic transducer serving as the signal generator inside the housing, a sound-conducting space between the signal generator and the sound-radiation outlet, and a control knob for regulating the volume of the signal generator which is connected to a potentiometer. One such telephone subset is known, for example, from DE-GM 79 10 907. In this subset, the tone ringer is accommodated on a special supporting member on which there is not only disposed the signal generator, but also the sound-conducting elements and the control knob for regulating the volume, and which is intended to serve as a compact subassembly group for replacing the conventional telephone ringer. The entire subassembly group is capable of being inserted in such a way into the set, that the sound funnel is acoustically decoupled from the interior space of the subset. The control knob partially protudes from the housing of the subset and is provided with a knurl for facilitating the operation thereof. Via a shaft, the control knob is connected to a potentiometer which, together with other electric components, is mounted on a printed circuit board. With the aid thereof, the volume of the tone ringer signal can be varied. Moreover, a further adjusting device is accommodated in the subassembly group. It is an object of the invention, with reference to a telephone subset of the kind referred to, to integrate the control knob for regulating the volume of the tone ringer in such a way into one wall of the housing of the subset, that it is flush with the top surface and yet easy to operate, the control knob being capable at the same time of serving as the sound radiation outlet, so that special sound apertures in the housing of the set may be omitted. According to the invention in its broadest aspect, a telephone subset of the kind referred to is characterised in that the control knob comprises a disc having a concentric, tubular projection provided with openings, along the circumference of which there is a sound channel widening in a helical manner, for serving as the sound radiation outlet, and opening up into the sound-conducting space, which surrounds the projection placed onto the sound outlet flange of the signal generator. The advantage of this construction resides in the simple, elegant connection between the control knob and the sound aperture, with the knob itself being completely integrated into the surface of the telephone set, while the sound aperture has in such a way become part of the control knob that the position of the control knob is simultaneously indicative of the volume to which the tone ringer has been adjusted. An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows the volume control device according to the invention, for the tone ringer of a telephone subset in a top view, and Figure 2 is a cross sectional view taken through the control device as shown in Figure 1. In the drawings, the housing of the telephone subset is indicated by the reference numeral 1. Into a circular cutout of one wall of the housing there is let a control knob 2 which, along its circumference, comprises a sound channel 3 extending over about 270 and which continuously becomes wider in that its inward edge follows the shape of a helix. The control knob 2 consists of a disc having a tubular, concentrical projection 6 directed toward the interior of the telphone set (Figure 2). This projection 6 traverses a plate 7 which, within the area below the disc of the control knob 2, comprises a funnel-shaped recess 14, so that a sound-conducting space 8 is created between the control knob 2 and the recess 14. Partly into the projection 6 of the control knob 2, there protrudes the tubular flange 9 of an electroacoustic transducer element serving as the signal generator 4, and which forms the sound exit thereof. The projection 6 is provided with openings, such as slots 10, thus permitting the sound to propagate from the projection 6 into the space 8 and from there through the sound channel 3 of the control knob towards the outside. The helical shape of the sound channel 3 simultaneously also serves to indicate the adjusted sound intensity which can be regulated via the volume control knob 2 and which is indicated by a marking 11 on the housing (Figure 1). Adjustment of the sound volume (intensity) is effected electrically by means of a potentiometer 12 which is mounted below the signal generator 4 on a printed circuit board 13 on which the oscillator and other componets of the telephone subset (not shown) are also accommodated. CLAIMS

2. A telephone subset as claimed in claim 1, characterised in that between the control knob (2) and the signal generator (4) there is inserted a plate (7) which is provided, below the control knob, with a funnel-shaped recess (14) forming the sound-conducting space (8).

3. A telephone subset as claimed in claim 1, characterised in that the projection (6) of the control knob (2) is provided with slots (10).

4. A telephone subset as claimed in claim 1, characterised in that the sound channel (3) extends over about 270 of the circumference of the control knob (2).

5. A telephone subset substantially as described with reference to the accompanying drawings.