US2180498A - Telephone coupling device - Google Patents

Description

Nov. 21, 1939.

J. C. BARN TELEPHONE COUPLING DEVICE Nov. 2l, 1939. '.J. c. BARNES TELEPHONE COUPLING DEVICE Filed Nov. 25, 19256 2 Sheets-Sheet' 2 INVENTOR JAMES c. BARN'ES FIG. 5

FIG. 6

ATTORNEY Patented Nov. 21, 1939 UiTEDY STATES ceri.

Associated Press, tion of New York New York, N. Y., acorpora- Application November 25, 1936, Serial No. 112,686

s claims.

This invention relates to a telephone coupling device.

An object of the invention is to provide a simple and inexpensive apparatus for connecting pic- 5 ture transmission systems and the like to standard telephone equipment.

vAnother object of the invention is the provision of a light and inexpensive device of small size by which portable picture transmission apparatus or other apparatus operating at audio frequency may be quickly and conveniently coupled to a telephone circuit Without the necessity of disturbing the telephone Wiring or equipment.

Apparatus for a similar purpose has been proposed by which connection is made inductively, or otherwise, at the ringer box, but such .equipment is more bulky than the present invention and consequently less suited for use for portable Z apparatus; and very often ringer boxes are located in inaccessible places making it inconvenient to attach such equipment.

It has been proposed also,A to use a current generated by a vibrating diaphragm controlled Afrom a telephone receiver, but this arrangement is not as compact as desired for portable equipment, and furthermore, a telephone controlled diaphragm introduces unnecessary distortion into a circuit.

3 The invention Will now be described with the aid of the accompanying drawings of which Figure v1 is a schematic diagram showingthe magnet of a telephone receiver and the present invention with the receiver diaphragm between 35 the respective magnets.

Figure 2 is a similar diagram except that the telephone diaphragm is omitted for maximum energy transfer.

Figure 3 illustrates one method of rotatably coupling the present invention to the shell` of a telephone receiver.

Figures 4 and 5 show a modification of the invention which may be attached to a receiver without removing the receiver cap, Figure 5 being a section taken through 5-5 of Figure 4.

Figure 6 shows a brace for the polepieces made from a piece of Bakelite.

Referring now to the drawings: The reference character I indicates a conventional telephone receiver permanent magnet having windings 2 connected to outgoing circuits 3 and 4. The Wiring details oi the instrument and ringer box are omitted as unnecessary, but it will be understood that the receiver is connected to an outgoing line.

The square 5 indicates a picture transmission (Cl. 17e-2)' apparatus or other frequency controlled equipment located at adistant point. In the present instance the letter T indicates a picture transmitter which is connected through lines 6 and I to lines 3 and 4'. 5

The reference character I@ indicates alamihated core cr other magnetic circuit Whose ends are separated by the same' distance as that of the polepieces of the receiver magnet I. The core if laminatedmay be magnetized by a per- 10 man-ent magnet, or consist of laminations alone, or it may be a permanent magnet as in the case of certain types of telephone receivers.

Windings II and I2 on core ID are connected to each other in series aiding, While the exter- 15 nal terminals ofthe coils are connected respectivelyto lines I3 and I4 Which in turn are connected `to lines I5 and I6 extending from a picture receiving set, indicated diagrammatically by the square I'I and the letter R. In this em- 20 bcdim'ent the polepieces of core ID and preferably those of magnet` I rest against diaphragm I8 of the receiver.

Figure 2 shcwsa preferred embodiment of the invention differing only from that described 25 above in that the polepieces cfboth magnets are in Contact with each other.' In thiscase, the terminal. equip-ment is reversed from that or Figure land 5 is the receiver and Il vthe trans* mitter.

The assemblyk including core Il) and its coils are ypreferably. mounted in a casing, somewhat similar 'to the Well-known Watch case type of ear phone indicated in Figure 3 by the reference character I9, which is the same size at the edge as a telephone receiver. A convenient method of coupling the apparatus to a receiver is by means of a ring 29 suitably threaded at 2| to screw over the cap threads 22 of a receiver 23, While the opposite end of ring 20 has an inside 40 ange 24 which engages an annular ring 25 at the edge of `casing I9, which when the ring is tightened on the receiver shell will hold the respective magnets together, `or in a fixed position in respect to each other. Any Well known means may be employed, if required, to adjustthe core I0 in a longitudinal direction.

Figures 4 and 5 show another modification of the invention which may be attached tothe receiver of a telephone Without removing the receiver cap or otherwise disturbing the apparatus. This modification makes it possible for persons lacking'the mechanical skill to unscreW and replace a telephone receiver cap to connectv an audio frequency device to a telephone system.

This modiiication is particularly useful in connection with telephone news broadcasts now furnished to pool-rooms, clubs and the like of sporting events, in which the line signals are received via telephone and amplified and reproduced through suitable loud speaking apparatus.

In Figures 4 and 5 a conventional telephone receiver cap 3|) is shown having a circular central opening 3|, into which snugly fits polepieces 32, of a magnet I having windings II and I2 similar to those previously described.

The outer part of the polepieces in this embodi# ment, are preferably curved to t the circular opening 3| in the center of the receiver cap as shown in Figure 4.

The magnet I0 is preferably mounted in a shell 36 provided with one or more pairs of spring clips 31 which engage the underside of the receiver cap, rotatably securing the shell 36 thereto; the clips, shell and polepieces being of such dimensions that with the device in place, polepieces 32 buckle diaphragm I8 of the receiver slightly, pressing it against polepieces 40 of the receiver and preventing the diaphragm from vibrating.

When this embodiment of the invention is clipped tca receiver shell, it is not necessary to remove the receiver cap and diaphragm to locate the polepieces, as all that is required, once the device is in place is to rotate it in respect to the receiver shell until the desired signal level is reached. The respective poles are coaxial with the maximum signal transfer.

Operation The device operates as follows:

Assuming that the apparatus indicated at I1 is for transmitting pictures according to Well known practice, then the signal current to be transmitted sets up a magnetomotive force in core I0. In the case of Figures l, 4, and 5, the magnet circuit is partially through diaphragm I8 and the permanent magnet I of the receiver.

The flux produced by the signal voltage will divide between the two magnetic circuits. The part passing through the telephone receiver polepieces induces a voltage in the receiver coils 2 which will go out to lines 3 and 4 to the distant receiving apparatus 5. Likewise, if the receiving and transmitting apparatus were transposed, the incoming signal current Would induce a current in windings II and I2, which in this case would be connected to receiving apparatus as indicated in Figure 1.

For maximum transfer of energy, the polepieces of magnet I and core Ill should be coaxial. Figure 2 shows the most efficient arrangement as the polepieces are in contact and there is no division of the magnetic circuit through a diaphragm. If desired, the signal level may be con.- trolled by rotating the magnets I and I0 in respect to each other, as previously stated.

, yW hat is claimed is:

1. In a device of the character described, an

electric circuit and a telephone system including receivers; means to connect said circuit to said telephone system, which includes a pair of magnets connected tosaid circuit, polepieces for magnets shaped to i'lt the opening in a receiver cap, and means for securing the first mentioned means to a telephone receiver so that said polepieces extend through the opening in said receiver cap and engage the diaphragm of said receiver.

2. In a device of the character described, an electric circuit and a telephone system, including telephone receivers; means to connect said circuit to said telephone system lwhich includes a pair of magnets connected to said circuit, polepieces for said magnets shaped to fit the opening in a receiver cap, and means for securing the first mentioned means to a telephone receiver so that said polepieces extend through the opening in said receiver cap and engage the diaphragm of said receiver pressing it against the receiver polepieces and thereby preventing the diaphragm from vibrating.

3. In a device of the character described, an electric circuit and a telephone system including telephone receivers; means to connect said circuit to said telephone system which includes a pair of magnets connected to said circuit, polepieces for said magnets shaped to t the opening in a receiver cap, and means for rotatably securing the first mentioned means to a telephone receiver so that said polepieces extend through the opening in said receivercap and engage the diaphragm of said receiver pressing it against the receiver polepieces and thereby preventing the diaphragm from vibrating, means for adjusting the signal current which comprises rotating said magnets in respect to each other.

JAMES C. BARNES.

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