US2186072A - Head phone - Google Patents

Description

Jan. 9, 1940.- w, H HUT 2,186,072

HEAD PHONE Original Filed June 22, 1936 Patented Jan. 9, 1940 UNITE srres PATENT OFFICE.

HEAD PHONE Walter H. Huth, Chicago, 111., assignor to Aurex Corporation, Chicago, 111., a corporation of Illinois 5 Claims.

This invention relates to so-oalled head phones for telephone apparatus, and more especially those that have an ear-piece for eachear.

This application is a division of co-pending 5 application Serial No. 86,504, filed June 22, 1936, now Patent No. 2,107,416, issued Feb. 8, 1936.

Generally stated, the object of my invention is to provide an improved construction and arrangement whereby one ear-piece of a double head phone has a variable resistance, whereby to balance the efiect in both ears, for a person whose hearing is not the same in both ears, in combination with volume control.

It is also an object to provide certain details and features of construction and combinations tending to increase the general efficiency and desirability of an apparatus of this particular character. v

To the foregoing and other useful ends, the invention consists in matters hereinafter set forth and claimed and shown in the accompanying drawing, in which Fig. 1 is a perspective of a head phone embodying the principles of the invention.

- Fig. 2 is a side elevation of one of the earpieces, on a larger scale, partly in vertical section.

Fig. 3 is a front elevation of the ear-piece shown in Fig. 2, on a smaller scale, with a cover plate shown removed.

Fig. 4 is an enlarged detail section on line 44 in Fig. 3.

Fig. 5 is a diagram of the circuits of the head phone and the power line connection.

Fig. 6 is a front elevation of the plug of said connection.

As thus illustrated, the invention comprises an ear-piece l of the double head phone, provided with a variable resistance in the form of two par- 40 allel strips 2, of suitable resistance material, connected in shunt in. the circuit of this earpiece, so that this resistance is in shunt of the active element of the ear-piece, together with a metal slide-piece 3 engaging both strips of resistance, the slide-piece having a handle 3 extending through the slot 5 in the casing t for enclosing this variable resistance. By moving the handle l along the slot 5, the resistance will be Varied, and in this way the ear-piece I can be regulated to increase or decrease the strength of the action therein, in order to balance the sound in both ears, for a person whose hearing is not the same in both ears. In this way, and with the variable resistance I in the connection plug 8, each person can regulate the head phone in accordance with the hearing, and in a manner to balance the volume efiect in both ears. It will be understood that the plug 8 is at the end of "the cord 9 leading from the head phone, and that I, the resistance 1 is in shuntof the resistance 2 and 2 and is in bridge of the main line ll] of .the apparatus. The movable contact I i, as shown, is in series with the resistance 2 of the head phone. Thus the resistance 1, or any portion thereof, can

be included in series with the head phone. 10

Obviously, the variable resistance 1 will operate as a volume control, so that the volume can be regulated or controlled without disturb ing the balance obtained, as between the two ear-pieces, by the adjustment of the variable resistance on the ear-piece I, for when the balance is obtained, it then does not need to be disturbed in order to vary or control the volume.

Thus, with people whose hearing is not the same in both ears, the variable resistance 2 can be used to regulate the relative effect in the two ear-pieces shown in Fig. 1 of the drawing, to insure in efiect to the user or listener practically the same volume effect in both ears, as by careful adjustment of said resistance the telephonic message will sound substantially as loud in one car as in the other. Thereafter, without disturbing said adjustment, the variable resistance 1 and I I can be employed to regulate the volume effect in both ears, inasmuch as the resistance 1, although bridged on the main circuit In and. normally in shunt of the double head phone, is adapted by movement of the contact II to be included entirely or in part in series with the head phones. As shown in Fig. 5 of the drawing, 5 only a relatively small portion of the resistance 1 is in series with the headphone, but by swinging this element H to the left, it is obvious that a greater portion can be thus included in series with the receiving instrument, so that after bal- 40 ancing the effect in the two cars, so to speak, the volume control can then be regulated without disturbing the said balance.

As is well known, and as indicated in Fig. 2, the casing of an ordinary ear-piece of a double head phone of this kind is commonly made of rubber or vulcanite or other insulating material. As indicated in Fig. 2, the two flat resistance strips 2 are preferably secured to a base strip of insulation, shown in section in Fig. 2, and the unitary flat structure thus formed is then fastened fiatwise upon the outside of the outer wall of the casing of the ear-piece, in any suitable or desired manner. Then the cover 6, with the handle 4 of the slide 3 protruding through the slot 5, is then fastened in place to the said casing, by the screws shown at top and bottom in Fig. 2 of the drawing, so that the slot 5 will be vertical, thereby making it easy to adjust the shunt resistance thus formed by straight up and down sliding movement for the desired purpose. Thus the invention can be applied to any ear-piece of this kind, as an attachment for the outside thereof, instead of having to be built into the earpiece when the latter is originally constructed. The two wires of the cord connection 9 extend under the cover 6, as indicated in Fig. 1 of the drawing, and lead to the two large screws shown in Fig. 4 of the drawing, which screws have metal portions that extend toward each other and engage the flat strips 2 in the manner clearly shown in Figs. 3 and 4 of the drawing. Thus the cover 6 can be easily removed to repair the adjustable shunt resistance thus provided, if necessary or desirable.

What I claim as my invention is:

1. The combination of a double ear-piece head phone, with each ear-piece connected in the same circuit, so that they simultaneously receive the message, and adjustable shunt resistance means disposed fiatwise on the outside of the outer wall of the casing of one ear-piece, having straight sliding movement to vary the resistance of the shunt, afiecting the active element thereof, in series with the active element of the other earpiece, thereby to balance the volume efiect in both ears.

2. A structure as specified in claim 1, and a separate volume control in circuit with both earpieces.

3. A structure as specified in claim 1, and a separate volume control in circuit with both earpieces, with a portion thereof always in shunt of each ear-piece, this separate control being incorporated in a switch plug at the end of a flexible cord leading to said phone.

4. A structure as specified in claim 1, comprising a second volume control in shunt of said adjustable shunt resistance and in shunt of the active element of each ear-piece.

5. A structure as specified in claim 1, comprising a casing covering said shunt resistance, fastened to the outer side of the ear-piece, with a vertical slot in said casing, and a contact member slidable in said slot and engaging the shunt resistance, the latter comprising parallel fiat'strips insulated from each other and included in series in the shunt circuit.

WALTER H. HUTI-I.

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