U.S. patent number 3,862,379 [Application Number 05/377,897] was granted by the patent office on 1975-01-21 for headphone construction for interpreter translator arrangements.
This patent grant is currently assigned to AKG Akustische u. Kino-Gerate Gesellschaft m.b.H.. Invention is credited to Ernst Pless.
United States Patent |
3,862,379 |
Pless |
January 21, 1975 |
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.
Inventors: |
Pless; Ernst (Vienna,
OE) |
Assignee: |
AKG Akustische u. Kino-Gerate
Gesellschaft m.b.H. (Vienna, OE)
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Family
ID: |
3581306 |
Appl.
No.: |
05/377,897 |
Filed: |
July 10, 1973 |
Foreign Application Priority Data
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Jul 11, 1972 [OE] |
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5948/72 |
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Current U.S.
Class: |
381/74;
381/372 |
Current CPC
Class: |
H04R
1/1041 (20130101); H04R 1/1008 (20130101); H04R
5/0335 (20130101) |
Current International
Class: |
H04R
1/10 (20060101); H04m 001/02 (); H04m 001/05 () |
Field of
Search: |
;179/167,168,2B,19W |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1,062,672 |
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Mar 1967 |
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GB |
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602,063 |
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Jul 1960 |
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CA |
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Primary Examiner: Cooper; William C.
Attorney, Agent or Firm: McGlew and Tuttle
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.
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.
* * * * *