US834497A - Transmitting apparatus. - Google Patents

Description

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No. 834,497. PATBNTBD 001230, 190s.

H. SHOBMAKBR.

TRANSMITTING APPARATUS.

APPLICATION FILED IAB. 2,'1906.

? QVENT? M1245@ ATTORNEY UNITED sTATEs PATENT oEEro-E.

HARRY SHOEMAKER, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO INTERNATIONAL TELEGRAPH CONSTRUCTION COMPANY, A COR- PORATION OF NEW YORK.

Specification of Letters Patent.

Patented Oct. 30,' 1906.

Application led January 2, 1906. Serial No. 294,040.

To all whom, it may concern:

Be it lmown that I, HARRY SHOEMAKER, a citizen-of the United States, residing at Jersey City, in the county of Hudson and State of New Jersey, have invented a new and useful Transmitting Apparatus, of which the following is a specification.

My invention relates to telegraph transmitting apparatus, and more particularly to means for controlling the operators key. i My invention resides in apparatus for minimizing sparking at keycontacts, especially when the key is required to control an alternating or fluctuating current and when such current is of considerable magnitude, as in the case of telegraph systems employing electroradiant energy and commonly known as wireless-telegraph systems.

In some telegraph systems, especially wireless-telegraph systems, the operators key is required to control or interrupt considerable energy with certainty and clearness. Large currents cause danger of destruction of the key-contacts by arcing or sparking. To this end I associate with the operators key an electromagnet connected either in series with or in shunt to the circuit controlled by the key, such magnet operating to retain the key in closed position until the alternating or fluctuating current reaches or nearly reaches its minimum value.

For several of the forms my invention may take reference is to be had to the accompanying drawings, in which- Figure 1 is a side elevational view, partly in section, of a telegraph-key and an associated electromagnet. Fig. 2 is a vertical elevational view, partly in section, taken at right angles to Iig. 1. Fig. 3 is a diagrammatic view of simple transmitting-circuits involving an electromagnet associated with the key having its Winding in series with the circuit controlled by the key. Fig. 4 is a view similar to Ii ig. 3, except that the electromagnet-Winding is connected in shunt to the circuit controlled by the key. Fig. 5 is a fragmentaiy diagrammatic view showing a modification of l* ig. 4.

Referring to Fig. 1, K is an'operators key pivoted at 1 and having the usual finger-button 2. A spring or other means (not shown) serves to keep the key in open-circuit position, as is well understood and coInInol; in

telegraphy. The key-contacts are shown at 3 and 4.

5 is an iron armature, preferablylaminated, secured to the under side and extending transversely ofthe key-bar K.

6 6 are vertically-extending magnet-cores having the common yoke or back armature 7, the latter resting upon the adj usting-screw 8, passing through a member 9, constituting a portion of or a xture to the frame in which the bar K is pivoted. Embracing each core 6 is a closed-circuited winding or circumferentially-continuous tube 10, of copper or other well-conducting material. The tubes 10 10 may terminate in flanges 1 1, which may serve both to radiate any excessive heat that may be generated in the tubes 10 10 and as a Winding-space for the windings 12 12, which may be either series or shunt windings, as hereinafter described.

In Fig. 3, simply by way of example,` a l simple Wireless-telegraph transmitting apparatus is shown, and applied thereto is my invention. A represents a simple aerial conductor, between which and the earth connection E is a spark-gap g. Bridging the sparkgap is the secondary S of a step-up transformer whose primary is shown at P. In series with the primary P is the generator or source of electricity G, preferably an alternating-current generator. For long-distance Working considerable energy must be delivered by the generator G and must be controlled by the key at its contacts 3 and 4, which are also connected in series with the rimary P and with the Winding 12 of the e ectromagnet. The conducting-tubes 10 10 are shown diagrammatically only. When the key K is depressed by the operator, the current flows through the winding 12 and the primary P in series, causing sparks at the gap g and the radiation of electroradiant energy from A` In so depressing the key the armature 5 has been brought within the range of action of the poles of the cores 6 6 and attracted thereby, thus, in effect, assisting the operator in holding the key down in circuit-closed position. Remembering, however, that the current in the circuit of the key4 is an alternating one or a fluctuating one, it may occur, as `it does requently in practice, that the operator will remove the pressure from the key at an instant of time When the current in the circuit IOO is at or near its maximum, or at any rate at a value considerably greater than zero. In the absence of the electromagnet, as here shown, the key would open at the instant the operator removed the pressure, with resultant spluttering and arcing at the contacts 3 and 4, due to the fact that at that instant the current is of considerable magnitude. This arcing and s luttering soon destroys the efficiency of a ey, requiring its replacement or at least interfering with the' transmission of clear sharp signals. By the use of the electromagnet, however, the key is held over an interval of time after the operator may have released pressure when the current is at: a considerable value. When the current reaches or approximately reaches its minimum value, howe ver, the strength of the magnet is correspdingly reduced and releases the key at t instant of small or zero value, with the rt ult that practically no arcing occurs at the contacts 3 and 4. This means that such contacts are not damaged, have a long life, and that the signaling is and continues to be clear and sharp.

l Since the windings 12 12 upon the cores 6 6 are inductive ones in the-relation shown, the current lags behind the impressed electromotive force, as is well understood in the art of alternating currents. The closed-circuit.- ed Winding or. circumferentially-continuous tubes 10 10 serve as closed secondaries and tend to bring the current and electromotive force more nearly into phase-that is, they tend to shift the phase ofthe magnetism.

In Fig. 4 the arrangement is similar' to that in F ig. 3, except that the key, the generator G, and primary P are in series With each other, no electromagnet-winding being series in-this case. However, the -magnet-Winding 12 u on the core 6 is connected in shunt to the circuit controlled by the key, so that the key controls the circuit, of the magnet l2 as well as that of the primary P. In this case the number of turns upon the ma net is greater-than in the case of Fig. 3 and t e selfinductionis also considerably greater. To shift the phase of the current with respect to the electromotive force in the coil 12', the circumferentially continuous tubes 10 .10 o erate as closed secondaries. The adjustahle or suitable condenser C may be connected in series with the Winding 12 to bring the current more nearly in phase with the electromotive force or to otherwise shift the current, hase or the phase of the magnetism. Either t e condenser C or the tubes 10 10 may be used separately and independently or all may be used conjointly.

In Fig. 5 the arrangement is similar to that inF-ig. 4, except that the condenser C is connected-in shunt to the magnet-windin l2.

Iy the apparatus herein descrlbed the operators key, if not released by the operator at or near the instant of minimum current in the circuit, is held over by an electromagnet and then released by the magnet at or near the instant of 'minimum current, with resultant reduction of arcing or sparking, as heretofore described.

By adjusting the screw 8 the electromagnet may be caused to approach or recede from the armature 5, thus giving an advantageous adjustment for the control exercised by the electromagnet.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a telegraph-transmitter, anl operators key, a source of alternating/or' fluctuating current, an electromagnet operating upon said key, the winding of said: magnet being connected in shunt to the circuit controlled by said key, whereby said key isrpermitted to return to normal position only at or nearthe instant of minimumcurrent.

2. In a telegraph-transmitter, an operators key, a.I source offluctuating or alternating current controlled by said key, an electromagnet associated with said key for permitting its return to normal-position only at or near the instant of minimum current and ai phase-shifting device associated with said electromagnet.

3. In a signaling system, anoperators key, a source of iiuctuatin or-alternating current controlled by said ey, an electromagnet associated with said key for ermitting its returnto normal position on y at' or near the instant' of minimum current, and a closed-circuited winding associated with the Winding of said electromagnet.

4. In asignaling system, an. operators key, a source ofl uctuating or alternating current controlled thereby, anelectromagnet associated with said key for permittingits return to normaliposition only at: or near the instant of minimum current, anda condenser associated with-the winding of' said electromagnet. 4

5. In a wireless signaling system, afradiating-conductor, a source of fluctuating or alternating current-for supplying energy thereto, an operators key for controlling said energy, an electromagnet associated with said key for permitting its return to normal position only at or near the instant of minimum current, and a phase-shifting device associated with the winding of said electromagnet.

6. In a wireless signaling system, aradiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, an operators key for controlling said energy, an electromagnet associated with said key for permitting lts return to normal position only at or near the instant of minimum current, and a closed-circuited winding associated with the winding of said electromagnet.

7. In a wireless signaling system, a radiat.-

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ing-conductor, a source of fluctuating or alternating current for supplying energy thereto, an operators key for controlling said energy, lan electromagnet associated with said key for permitting its return to normal position only at or near the instant of minimum current, and a condenser associated with the Winding of said electromagnet.

8. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, an operators key for controlling said energy, and an electromagnet, having its Windin connected in shunt to the circuit controlled by said key, for permitting the return of the key to normal position only at or near the instant of minimum current.

9. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, a key for controlling said energy, an electromagnet associated with said key for holding it closed until at or near the instant of minimum cu'rrent, and a closed circuit associated With the magnetic circuit of said magnet.

10. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, a key for controlling said energy, an electromagnet associated with said source of energy and key for holding said key closed until at or near the instant of minimum current, and a conducting-sleeve associated With the magnetic circuit of said magnet.

11. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, a key for controlling said energy, an electromagnet associated with said key for holdin it closed until at or near the instant of minimum current and a phase-shifting device associated With a Winding of said magnet.

12. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, a key for controlling lsaid energy, an electromagnet associated with said key to hold it closed until at or near the instant of minimum current, a Winding of said magnet being connected in shunt to the circuit including said source of energy, and a phase-shifting device associated-With said Winding.-

13. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, a key for controlling said energy, an electromagnet associated With said key to hold it closed until at or near the instant of minimum current, a Winding o f said magnet being connected in shunt to the circuit includin said source of ener y ary; controlled by saicgl key, and a phase-s iftigA g device associated Said '53.5'

14. In a Wireless signaling system, a radiating-conductor, a source of fluctuating or alternating current for supplying energy thereto, a key for controlling said energy, and an electromagnet associated with said key for holding it closed until at or near the instant oi minimum current, a Winding of said magnet being connected in shunt to the circuit ilpcluding said source and controlled by said 15. In a Wireless signaling system, a radiating-conductor, a source of fiuctuating or alternating current for supplying energy thereto, a key for controlling said energy, an electromagnet associated With said key to hold it closed until at or near the instant of minimum current, a winding of said magnet being connected in shunt to the circuit includino said source of energy, and a closed circuit and a condenser associated with said magnet- Winding.

In testimony affixed my signature in the two subscribing Witnesses.

HARRY SHOEMAKER.

whereof I have hereunto presence of the Witnesses:

ALICE S. MARSH, AGNES Rim).

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