Headphone Construction For Interpreter Translator Arrangements

Abstract

A headphone which is usable particularly along with a plurality of other headphones includes a transducer which is connected through a switch to the source of current. The switch provides a means for automatically turning the transducer either on or off. In one embodiment the switch includes a mercury switch which when oriented in an inactive or nonoperative position, ensures that the transducer is turned off and in another position in which operation normally takes place, will ensure that the transducer is turned on. Another embodiment includes a spring operated switch control which is operated when the earphone, for example attached to a headband, is positioned on the head of a user. Such a switch may be spring actuated or may include a member which is displaceable when the resilient cushion for the earpiece of the earphone is compressed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to a construction of earphones and, in particular to a new and useful earphone having switch means for turning the transducer to an off position whenever the earphone is not in use and which is particularly applicable for multi-earphone installations such as interpreter translator arrangements.

2. Description of the Prior Art

The present invention is particularly applicable to the construction of a headphone which is adapted to use either for interpreters or translators in a multi-headphone installation such as would be the case in language schools and in speech clinics where there are a plurality of headphones arranged for operation in a relatively confined space. In such arrangements headphones are employed in great numbers and in many installations a large number of them which are connected to the amplifier output are not employed at any given time but are simply lying idle on a table or a desk. The ones that are not used are in a situation such that they radiate freely the sound they produce. They thus produce a proper sound that can be disignated as "twitter." Such a twitter appears due to the fact that the headphones which are not used do not have a close coupling connection between the transducer diaphragm and the operator's ear and therefore the diaphragm is not loaded by the ear impedance and it is in a position to vibrate in its resonance frequencies undamped so as to produce non-linear distortions and to radiate high tones. This phenomena is particularly present when a great number of headphones are not employed and the noise they produce creates a considerable disturbance.

SUMMARY OF THE INVENTION

The invention provides a headphone which will remain mute when it is not employed. For this purpose the headphone includes a selfoperating switching device which depends upon the position of the headphone at any particular time and which will act to switch the headphone off whenever the headphone is not in an operative position.

In one embodiment of the invention the switching device comprises a mercury switch which when oriented in an operative position, will be connected to the electrical connection and to the transducer in which in a non-operative position will disconnect the transducer from the current supply.

In accordance with another embodiment of the invention, the switch includes a spring loaded switch member which when the earphone is in a position of operation, will cause the connection of the transducer but will disconnect the transducer when it is not. This function can be attained most simply by arranging the transducer housing so that it is axially shiftable so that by applying pressure of the springy headband of a headset, the switch will operate to connect the transducer member to the current supply. The axial shiftability of the transducer can be attained, in the best manner, by locating it in an elastic, springy earpiece in such a manner that when the headphone is put on, a pressure is exerted on the transducer to cause it to shift. This shifting movement of the transducer causes actuation of the switch. The changover position of the switch can be made very small so that a slight shifting movement of the transducer is sufficient to actuate the switch device. A simple on-off switch arranged in series electrically and connected to the electro-acoustic transducer will suffice. If the impedance for the amplifier output has to remain at least constant, then it is advisable to provide a changover switch in the housing which switches an ohmic equivalent resistor into the circuit when the headphone is not utilized.

Accordingly, it is an object of the invention to provide a headphone which includes a switch connected to an electroacoustic transducer and which operates to turn the transducer off whenever the headphone is not utilized.

A further object of the invention is to provide a headphone which includes a switch such as a mercury switch or a spring actuated switch which is effective to turn off the transducer whenever the headphone is not operated and which, for example, may be turned on when the headphone is positioned over the head of the wearer, such as by the compression of the headpiece over a person's ear.

A further object of the invention, is to provide a headphone construction which is simple in design, rugged in construction and economical to manufacture.

For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

In the Drawings:

FIG. 1 is a transverse sectional view of a headphone constructed in accordance with the invention;

FIG. 2 is a partial transverse sectional view and partial elevational view of a headset having an earphone similar to that shown in FIG. 1;

FIG. 3 is a transverse sectional view of another embodiment of the invention; and

FIG. 4 is a transverse sectional view of still another embodiment of the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in particular, the invention embodied therein comprises in FIG. 1, a headphone in the form of a single earphone which is designed so that it can be suspended on the person's ear by means of an annular ear clip 1. In this embodiment the transducer 3 is arranged within a housing 2 and it is operated when it is connected electrically to a current supply through a mercury switch 5 having switch contacts 6. In this embodiment, a mercury switch dependent upon the position of the headphone is indicated since the applying pressure is too small to actuate a springloaded contact for switching the transducer either on or off. In the operated position, shown in FIG. 1, the mercury switch is operated to connect the transducer 3 for use. The transducer 3 is an electro-acoustic transducer which is contained in the headphone housing 2 at a location in which it protrudes lightly toward the band clip 1. It is surrounded by a soft foam rubber ring 4 which is in a location which will be pressed against the ear when the band is positioned therearound. When the headphone is not in use, the metallic mercury within the mercury switch will not produce an electrical current between the contacts 6 so that the transducer 3 will be turned off. In the embodiment shown the switch 5 is a simple on-off switch, but further contacts may be provided in order to carry out other distinctive functions.

In the double headphone set shown in FIG. 2, the mercury switch 5 is provided which is accomodated within a housing 7, and which is connected to the acoustic transducer 3. In such an arrangement it is not necessary to mount the switch 5 into both headphone housings 7, because even in the case of stereo operation a single switch is sufficient in the common return circuit for putting the transducer out of operation.

In the embodiment shown in FIG. 3, there is a switching arrangement which responds to pressure. The necessary pressure is created when putting on the headphone by the spring headband 8 which strives to press the earpieces against the wearer's ears. In the inside of the headphone housing 7 are provided electrical contact springs 9 that are designed similar to relay contacts. One of the two contact springs 9 is fixed while the other is movable and is connected through an actuating member 18 with the transducer 3. The transducer 3 is fixed with its ear-side end in a disk 11 which is made, for example, of soft plastic or rubber material or which may comprise a metal diaphragm which is covered with an ear cushion 12. For supporting the elastic force of the disk 11, a spring arrangement 10 can also be provided at the rear end of the transducer. It is easy to see that when the headphone is put on, contact springs 9 will touch each other and switch the transducer into the current circuit. Only a simple on-off switch is necessary, but the switch arrangement can be provided with more contact springs which enable the switch to have several functions if desired.

In the embodiment shown in FIG. 4, a transducer 3 is connected through a rigid contacting member 18 to a microswitch 13 which is fixed to the inner side of a rear wall of a housing 14. The transducer is arranged so that it can be axially shifted. A foam material cushion 15 is put over the housing 14 and the transducer 3. A headband 16 is hinged to the housing 14 and it may be pivoted on a continuation 17 of the microswitch 13. When the headphone is put on, the elastic force of the band 16 presses against the foam material cushion between the ear and the headphone phone 14, causing the shifting of the transducer 3 by a short distance within the inner portion of the housing 14. This results in actuation of the switch 13 and thus a connection between the transducer and the amplifier output is established. When the headphone is taken off, the foam material of the cushion 15 expands and the transducer 3 returns to its resting position. Due to the rigid connection with the switch 13 through the actuating member 18, the current to the transducer is interrupted by the opening of the switch 13.

The invention is not limited to the use of a mercury type switch or any particular spring actuated switch. Other type switches such as gravity switches, ball switches and the like may be provided.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

What is claimed is:

1. A headphone construction particularly for language school and interpreter installations, comprising an earphone housing having an open ear facing end, a cushion affixed to said housing and extending outwardly around the open end, an electroacoustic transducer in said housing, an electrical current supply connected to said transducer and having an interrupter switch, said switch having means for disconnecting electrical current supply to said electroacoustic transducer and having first and second contact which are normally opened but which are engageable to actuate said circuit, a spring between said transducer and one of said contacts holding said transducer against said cushion and being displaceable by compression of said cushion when it is engaged with a user's ear to urge said transducer against said spring and to cause said spring to move one of said contacts to engage the other of said contacts, and a head band on said housing for biasing said housing against a person's ear.

2. A headphone according to claim 1, wherein said switch comprises a microswitch, said microswitch containing said spring.

3. A headphone according to claim 1, including a diaphragm secured to the inside of said cushion around said opening of said housing and carrying said transducer.