US1321990A - Lands - Google Patents

Description

PIETER DE LA NGE AND ROBERT AERNOUT BARON VAN LYNDEN. HEATING c'omnucron FOR THERMIC TELEPHONES. IAPPLFCATION FILED NOV. 4,.195.

Patented Nov. 18, 1919.

- Pieterdella e ud .Fobez-ilferlwzztjaron v'dnmden orzey UNITED STATES PATENT. OFFICE.

PIETER DE LANG-E AND ROBERT AERN OUT BARON VAN LYNDEN, OF UTBECHT', NETHER- LANDS, ASSIGNORS, IBY MESNE ASSIGNMENTS, TO AMERICAN T'I-IERMOPHON E COM- PANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

HEATING-CONDUCTOR FOR THERMIG TELEPHONES.

Specification of Letters Patent.

, Patented Nov. 18, 1919..

Application filed November 4, 1915. Serial No. 59,623.

To all whom it may concern:

Be it known that we, Prnrnn on Lance, and ROBERT AERNOUT BARON VAN LYNDEN, both subjects of the Queen of the Netherlands, and residing at Utrecht, in the Neth erlands, have invented new and useful Improvements in I-Ieating-Conductors for Thermio Telephones, of which the following is a specification.

ur invention relates to heating conductors for thermic telephones, and has for its object to provide a heating conductor which owing to its novel structure afi'ords the greatest possible sound producing length within a comparatively small space.

Heating conductors according to our invention are illustrated by way of example in the accompanying drawings, in which Figure 1 shows, in elevation, one form of heating conductor according to our invention, while Fig. 2 similarly illustrates a modification.

Referring to Fig. 1 the illustrated heating conductor consists of a Wollaston wire 2 having round or flattened legs 1 and an intermediate portion formed into a complete loop 3.

Instead of one complete loop, the heating conductor may have tWo or more such loops. Fig. 2 illustrates heating conductor l with two complete loops 5 and 6. As'in Fig. 1, the ends of the wire are provided with laterally-bent legs 7, which, as in Fig. 1, may be round or flat in cross section.

By a complete loop we mean one in which the bend extends through an angle of at least 360, so that when viewed as shown in the drawings, portions of the wire will ap pear to cross each other.

Forming the wire with a complete loop or a plurality of such loops has the advantages that its sound emitting length is as great as possible while the wire does not require more space than the ordinary, areshaped wires. It will be understood that said complete loops form part of the sound emitting portions or sound portions of the wires. The VVollaston wire formed as described is dipped in a bath of acid with its loop-shaped part hanging down, and exposed to the ac tion of the acid for the desired length. Instead of preparing the wire by the Wollaston process, an exceedingly fine Wire, the heating conductor, as required for the purpose specified, may also be obtained by drawing or spinning the wire from liquid metal.

We claim:

1. A heating conductor for thermic telcphones, provided with a loop and with alining ends integral with said loop and bent laterally in opposite directions.

2. A heating conductor for thermie telephones, provided with a central looped or coiled sound portion of more than 360 and laterally-bent ends integral with said looped portion.

In testimony whereof, we have signed this specification.

PIETER DE LANGE. ROBERT AERNOUT BARON VAN LYNDEN.

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