US1407761A - Electric-arc-striking mechanism - Google Patents

Description

C. M. LANGFELD.

ELECTRIC ARC STRIKING MECHANISM.

APPLICATION FILED MAY 13, I9I9.

Patented Feb. 28, 1922.

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usual arc lamp construction the negative is UNITED STATES 'PATENT OFFICE.

CLARENCE M. LANG-FEED, OF BALTIMORE, MARYLAND.

ELECTRIG-ARC STRIKING MEGHANISM 1,4omo1.

Application filed May 13,

Specification of Letters Patent.

Patented Feb. 28, 1922.

1919. Serial No. 296,925.

(FILED UNDER. THE ACT 01 MARCH 3, 1883, 22 STAT. L, 325.)

To all whom it ma concern:

Be it known that I, CLARENCE M. LANG- rnnn, a citizen of the United States, and a resident of Baltimore, in the county of Baltimore and State of Maryland, have invented alty thereon.

My invention relates to electric arc mechanisms for light projectors or searchlights and has for its object to provide a simple and reliable device by means of which the arc'may be struck.

In the 00:]P8I1d111g application of Lyman C, Josephs, r., Serial Number 302,313, filed January 5, 1919, there is shown and described an electric arc mechanism in which the negative carbon is adapted to be manually operable towards the positive gar-bin n t e adapted to be normally held away from the positive carbon by means of a spring but experience has demonstrated, if the operator holds the negative carbon in contact with the positive carbon too long or draws the are too slowly, the heavy rush of current following the short circuit between the carbons is liableto blow the circuit breakers in the electrical supply circuit or otherwise damage thegenerating apparatus.

By my invention, I provide a device in which the arc is automatically drawn as soon as the carbons touch, regardless of the manner in which, the are striking rod may be manipulated by the operator, and while I have shown my are striking and release device as applied to the arc mechanism shown and described in the above mentioned copending patent application, it is to be understood that it may be as well applied to any other form of arc mechanism.

In the accompanying 'drawings;

Fig. is a transverse sectional view of an electric arc mechanism embodying my invention.

Fig. 2 is a sectional view along the line 2-2 of Fig. 1.

Fig. 3 is a detail view of my device after the are is drawn.

Referring to the drawings, the lamp mechanism comprises a hollow cylindrical casing 1 that fits within a suitable breech casting 2 that extends through a central opening 3 of a mirror 4.

A tube 9 is centrally supported within the casing 1 by means of end plates 10 and 11, preferably composed of insulating material. The plate 10 is provided with a socket 12 electrically connected to tube 9 by means of conductor 13 and brush 14:. The tube 9 is closed at one end by an annular plate 15 having a central opening 16 to accommodateportion 22, the latter having an operating handle 23 and being suitably supported by a bushing 24. A cylindrical sleeve 25 is located within the portion 21 and is adapted to be moved longitudinally therein by a rod 26 extending through portion 22 and provided at its end with a handle 27 An arc striker rod 28 housed by tube 18 is provided at one end with a carbon holder embodying an externally threaded union 29, and ampple 30 threaded thereon and formed with a socket 31 to receive the negative carbon 32. The hereinabove described are mechanism forms no part of this invention, and is referred to for descriptive purposes only.

My are striking and release device comprises a sleeve 33 designed to engage the inner end j of the rod 28 and is centrally formed with a transverse recess 34 within which are pivotally mounted radially acting pawls 35. To permit radial movement of awls 35 rod 28 is tapered as at 28*. Normal y pawls 35 project exterior of the sleeve 33 to engage detents 36 'pivotally mounted in opposing recesses in the sleeve 25 and normally forced I inwardly into the path of pawls 35 by springs 37. Pawls 35 are maintained in extended position by spring 38 which bears against the inner end of rod 28 and normally postions its tapered portion in advance of the pawls so that they bear upon the unre- E duced portion of the rod andare thus prevented from moving inward to released position until the rod has been moved inwardly to properly position its tapered portion beneath the inner edges of the pawls.

Having described the structural arrangement of this invention, its operation is as follows :Assuming the various parts of the. arc mechanism to be in their normal position as shown in Figure 1, to strike the arc, handle 27 is pushed inwardly to bring the electrodes into contact which is accomplished through the instrumentality of sleeve 25, cooperating pawls 35 and 36, sleeve 33 and rod 28, by which he ative electrode 32 and operating handle 2 are indirectly connected.

en the movement of the negative is arrested by contact with the positive electrode, sleeve 33 continues to move along the rod. 28, compressing spring 39, until pawls 35 reach portion 28 of the rod 28, the tapered configuration of which permits depression of awls 35 and releasement of sleeve .33. under the influence of spring 39, is caused to move rapidly to the rear until its movement is arrested by the shoulder 20. This retrograde movement of sleeve 33 withdraws negative electrode 32 and thus'very efl'ectively strikes the arc. After the arc has been struck, sleeve 25 is returned to its initial position. The negative carbon 32 may be then moved longitudinally by handle 23 reviously referred to.

h rom the foregoing, it is apparent that I have provided an are striking device by means of which the carbons are brought together and the are automatically drawn b a single movement of the operator, thus e iminating the possibility of a prolonged short circuit between the'carbons. While I have shown my invention in a simple and 'pon being released, sleeve 33 preferred form, as applied to a particular are mechanism, it is not so limited but is susceptible of various modifications within the scope of the appended claims.

I claim as my lnvention:

1. Tn an electric arc mechanism, the combination with a positive carbon and a negative carbon, a holder for said negative carbon and operating means for effecting longitudinal movement of said negative toward said positive carbon, of a release device interposed between said carbon holder and said operating means for automatically drawing an are between said carbons.

2. In an electric arc mechanism, the combination with a positive carbon and a negative carbon, a rod carrying said negative carbon, a sleeve slidably mounted on said rod, an operating rod provided with a sleeve portionsurrounding said first-named sleeve, and a device between said sleeve portions whereby said negative carbon rod and said operatin rod are adapted to move together in the direction of said positive carbon, of means for permitting relative movement of said rods in adirection away from said positive carbon.

3. In an electric arc mechanism the combination with a positive'and negative electrode including manually operable means for moving the negative in the plane of the positive electrode until contact of the electrodes has been effected; of a releasing device in connection with said means for automatically reversing the courseof the negative electrode concomitant with the determinatlon of its contact making movement, to produce an arc.

4. In an electric arc mechanism the combination with a positive and negative electrode including manually operable means for longitudinally movin the negative until contact with the positive electrode has been made; of a releasing device in connection with said means for automatically reversing the action of the negative electrode concomitant with the determination of its contact makin movement to roduce an arc.

C ARENCE M. ANGFELD.

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