US758842A - Wireless telegraphy. - Google Patents

Description

No. 758,842. PATENTED MAY 3, 1904. J. F. KING.

WIRELESS TELEGRAPHY.

APPLICATION FILED DBO. 17- 1902.

N0 MODEL.

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UNITED STATES Patented May 3, 1904.

PATENT OFFICE.

WIRELESS TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 758,842, dated May 3, 1904. Application filed December 17,1902. Serial No. 135,562. (No modeLl To all whom it TIMI/Z] concern:

Be it known that I, JAMES FOSTER KING, a citizen of the United States, residing at l/Vashington, in the District of Columbia, have invented certain new and useful Improvements in \Vireless Telegraphy; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. 7

My invention relates to improvements in wireless telegraphy, and more especially to an improved method of producing the disruptive discharge by which the electrical oscillations to transmit wireless messages are set up; and the principal object of said invention is to greatly reduce the potential required to create the necessary discharge.

It has hitherto been the practice in wireless telegraphy to produce the oscillations for transmitting by discharges, which take place between two or more normally separated discharge-points, it being necessary in such cases to supply a very high initial potential to break down the insulation of the air-gap, and therefore ,5 great extra expenditure of energy, necessitating also the employment of expensive and troublesome apparatus for the production of such high potential.

My invention contemplates doing away with the large permanent spark-gap, and thereby greatly reducing the resistance of the generator-circuit by normally bringing the terminals of said circuit into engagement with each other.

My invention further contemplates the propagation of vibrations in the vertical wire or vibratory circuit by forming a flaming are between said generator-terminals by separating them and suddenly connecting around said are a capacity in the vibratory circuit.

My invention further consists in the novel features hereinafter described, and particularly pointed out in the accompanying claims.

The principle of my invention and a specific form of apparatus for carrying out the same are illustrated in the accompanying drawings, in which Figure 1 is a diagram illustrating the principle of my invention and showing the apparatus in its inactive condition. Fig. 2 is a diagram representing the same parts in the active condition or in the act of transmitting; and Fig. 3 is a detail view, partly in vertical section, of a specific form of the discharging apj to the iron plunger or core 0 of a solenoid (Z,

This solenoid is excited by current from the battery f upon the closure of its circuit by the key 9 or other transmitting device. The terminals a Z) are connected, as by conductors l 2, to a suitable source of electromotive force it. Connected to the main spark-terminal a is an enlarged auxiliary terminal a, preferably having the shape of an oblate spheroid. This terminal a is separated in the case shown from the lower end of the aerial wire 0 or its equivalent by a very small spark-gap (0 A condenser 2', preferably of large capacity, is permanently connected around the spark-terminals by having one terminal connected to the earth-wire 3 and the other to the vertical wire, as shown.

Normally in the case shown the terminals (0 b are in engagement with each other, being held so by a spring acting on the solenoidplunger, as shown in Fig. 3 and hereinafter described, or the said terminals are separated by a relatively low or inappreciable resistance. Current will, therefore, traverse the terminals a 7) normally without causing a spark from a to a. When, however, the key is operated and the circuit 4 closed, the solenoid will draw in its core and cause the contact 6 to separate from the contact a, during which time a flaming arc will form across the space separating the terminals until the small airgap a is pierced, which will occur when the resistance of said air-gap (a is equal to that of the gap of the flaming arc. The moment the small air-gap a is broken down the generatorcurrents traverse a vibratory circuit comprising the vertical wire, condenser 2', and groundwire.

The sudden introduction of the large capacity of the condenser 'Z in multiple with the generator-circuit containing high self-induction will create surges in the vibration-circuit so long as the generator supplies sufiicient current to maintain the are between the contacts a and b and supply the condenser Z. When the key is released, the movable terminal Z) is brought quickly back' into its normal position. In transmitting the Morse alphabet, for example, a separate arc is formed across the spark-terminals for each element for a dot, an are for a given duration, and for a dash, an arc of longer duration.

In Fig. l the apparatus is shown in the normal condition with the key-circuit open, and in Fig. 2 the key-circuit is shown closed and the spark-terminals drawn apart.

From the above it will be seen that the electromotive force to form the spark may be relatively low and that alternators may be used with good results, although my invention may be used with any source of electromotive force found suitable for wireless telegraph work. I

Obviously either of the spark-terminals may be made tomove, or, indeed, both may be made to .move; but these are purely mechanical equivalents which do not affect the spirit of the invention. Furthermore, I may employ any desired means for reducing the resistance of the vibratory circuit by suddenly increasing its capacity and to form disruptive discharges across the said terminals for each symbol or element of the code transmitted. I may also employ any suitable means for operating the spark-terminals, whether this be mechanical or electrical, automatic, or otherwise.

In the specific form of apparatus shown in Fig. 3 the terminals a Z) are inclosed in a tube 70, of glass or other dielectric, and this tube is surrounded by a tube of suitable insulation Z, which extends preferably beyond the ends of the tube Z0. The upper end of the tube in is closed by a .plug or cap on, tapped into the upper end of the tube Z, and the lower end of tube 76 is closed by a cap 12, tapped into the lower end of said tube Z. The arcing terminal a and the sparking terminal a are connected by a shank or short rod 0, which passes through and is rigidly secured to the cap m, having the sparking terminal (4' outside of the tube 7c and the arcing terminal (0 inside of said tube. The shank 0 is enlarged, as at 0, and to this portion is connected. the terminal Z, connecting with the anode of the source of electromotive force. The lower end of the aerial wire 6 terminates, preferably, in a conical terminal g, mounted rigidly in a cap 1', which screws over the top of the tube Z.

The terminal Z) is mounted upon a short stem 5 tapped in the upper end of the iron plunger 0, which latter is adapted to reciprocate in the tube k. This plunger is bored out longitudinally to receive a rod 8, upon which it is adapted to slide, and this rod is in turn made 7 0 fast to a plunger or disk 6. Between this plunger and disk is a coil-spring u, which normally forces the plunger and terminal Z) upward. The downward movement of the plunger and terminalbis limited by the point '0 coming into contact with the rods. For the purpose of adjusting this downward limit the disk or plunger Z connects with an adjustable rod 10, screw-threaded in a sleeve 00, passing through the cap 2, the said adjust- 8O ing-rod being provided with a hand-wheel or, milled head 9. The sleeve 00 is preferably made of metal and is connected, as shown, to

the negative terminal 2, which leads to the source of electromotive force. of the solenoid is wound on a sleeve or spool slipped over the tube and carried by any suit able support. For the purpose of inspecting the spark-gap through the glass tube It the tube Z is provided with windows 2. not, however, wish to be understood as limiting my invention to any specific form of apparatus.

What I claim as my invention is The coil .0Z 5

I do 9 1. The improvement in wireless telegraphy,

which consists in creating an arc in a normally closed generator-circuit, and simultaneously'connecting around said are, a capac ity in a vibratory circuit, substantially for the purposes set forth.

2. The improvement in wireless telegraphy,

' which consists in creating a \flaming are 111 a normally closed generator-circuit, and simultaneously connecting in multiple with said arc, a capacity in a vibratory circuit, substantially for the purposes set forth.

3. The improvement in wireless telegraphy, which consists in creating in a normally closed generator-circuit a fresh are for each signal, and simultaneously connecting around said arc a capacity in a vibratory circuit, substantially as and for the purpose herein specified. I

In testimony whereof I afiix my signature in presence of two witnesses.

JAMES FOSTER KING.

Witnesses:

GRAFTON L. MoGILL, JOHN H. HOLT.

IIC

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