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Publication numberUS2245835 A
Publication typeGrant
Publication dateJun 17, 1941
Filing dateMay 11, 1939
Priority dateMay 18, 1938
Publication numberUS 2245835 A, US 2245835A, US-A-2245835, US2245835 A, US2245835A
InventorsFrank Stehlik Rudolph
Original AssigneeAss Telephone & Telegraph Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Telephone instrument
US 2245835 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

June 17, 1941.

R. F. STEHLIK TELEPHONE INSTRUMENT Filed May 11, 1939 INVENTOR. RUDOLPH FRANK STEHL/K Patented June 17, 1941 r Tau-reg ons ms'raurmn'r .Budolph Frank Stehllk, Antwerp, Belgium, as

signer to Associated Telephone & Telegraph. Company, Chicago, 111., a corporation oi Delaj ware Application May 11, 1939, Serial No. 272,951 In Great Britain May 18, 1938 2 Claims- (Cl. 179-403) I phone transmitter to'the mouth, for instance when wearing a gas mask.

In such circumstances it is known to provide a throat transmitter or so-called laryngaphone in addition to the normal telephone instrument. This has usually been provided as a separate unit which can be strapped around the neck and connected by a cord to the terminals of the instrument which incorporates a switching device permitting the cutting out of the handset transmitter and the switching-in of the laryngaphone. This arrangement has certain disadvantages as if it is necessary to listen as well as to speak, the receiver of the handset must still be held to the ear. Moreover the separate unit with straps and cord is awkward to handle and store and under certain conditions the cord and strap are liable to become tangled and .furthermore a switch has to be provided on the instrument and an extra operation is necessary to render the laryngaphone effective. The chief object of the present invention is to provide a neat and compact combined telephone and laryngaphone unit whereby the above difiiculties are avoided.

According to one feature of the invention in a telephone handset a unit including a receiver and microphone of ordinary type is provided with a socket for the plugging in of a throatoperated microphone.

According to another feature of the invention in a telephone handset a unit including a receiver and microphone of ordinary type is provided with facilities for plugging in a throat-operated microphone in substitution for the ordinary microphone.

The invention will be better understood from the following description of one method of carrying it into efiect which should be taken in conjunction with the accompanying drawing comprising Figs. 1-4. Of these,

Fig. 1 shows the normal handset,

Fig. 2 shows the plug-in portion comprising the laryngaphone,

Fig. 3 is a fragmentary view showing the laryngaphoue in plugged-in position and indicating the contact operation produced thereby, while Fig. 4 represents a suitable circuit diagram. It will be seen that the handset comprises the usual receiver I and microphone transmitter 2 Joined by the handle 3 which is split longitudinally and provided with the switching key 4 for connecting up the talking battery. The handle also includes the socket 5 adapted to receive the laryngaphone of Fig. 2. This comprises essentially the member 0 which is pressed against the throat to receive the speech vibrations and the plug portion I which fits into the socket 5 and makes the necessary electrical connections. As will be seen from Fig. 3 the plug spring I engages the spring 8 and moves it out of contact with the spring 8 thereby breaking the connection to the ordinary microphone and connecting up the laryngaphone in its place. It will be seen from the circuit diagram of Fig. 4 that the complete instrument includes a magneto It with the usual switching springs II and control contacts II, a bell I3, induction coil I4, buzzer l5, signalling key l1, and battery It.

These are connected in a more or less conventionalmanner to the terminals l9 and 20 extending to the line.

The laryngaphone element is conveniently housed in a casing of moulded material but metal or rubber may also be used if found more convenient. Moreover though in the system shown the plugging-in of the unit disconnects the ordinary microphone this is not essential and it might be thought desirable in some cases for both to remain connected up. It will be seen that the pin connections are sufiiciently long and robust for the laryngaphone to be held firmly in position after it has been plugged in. Its rigidity is increased by the fact that it secures a bearing against the projection 2| on the mouthpiece 2. It will be seen also that the shape and location of the unit are such that when it is plugged in the handset can be used with comparatively little change in position.

According to the invention therefore a very simple construction has been devised whereby a normal handset can be readily adapted to operation with a throat microphone with the minimum of additional equipment and the utmost convenience.


1. A telephone handset unit having a handle carrying the usual transmitter and receiver thereon, a throat operated microphone having a transmitter on one end and a receiver on the 10 other end, a laryngaphone having a plug extension rigid therewith, a socket in the handle between the transmitter and receiver and adjacent the transmitter, a built out projection on the transmitter adjacent the socket, said projection and said socket cooperating to hold the larynga'phone rigidly supported on the handle above the transmitter when the plug is inserted in the socket.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2624808 *Mar 30, 1949Jan 6, 1953Nat Pneumatic Co IncSignaling switch device
US3277243 *Dec 19, 1962Oct 4, 1966Burroughs CorpTelephone adapter
US4700383 *Jul 23, 1985Oct 13, 1987Fujitsu LimitedLock-releasing mechanism for telephone set with muting function
US7639825 *Dec 29, 2009Temco Japan Co., Ltd.Bone-conduction handset
US20090190781 *Feb 18, 2005Jul 30, 2009Mikio FukudaBone-conduction handset
U.S. Classification379/52, 381/151
International ClassificationH04M1/03
Cooperative ClassificationH04M1/03
European ClassificationH04M1/03