US1650779A - Testing electrode - Google Patents

Description

N(W. 29, 1927. r 1,650,779

A. F. WILLIAMS T E' STING ELECTRODE.

Filed Jan. 25. 1924 I III/Ii777'7 i 'ing shield'whi'ch Patented Nov. 29, 1927..

UNITED ANTHONY F. WILLIAMS, ROCHESTER, NEW YORK, ASSIGNOR TO NORTH EAST ELEC- TRIO COMPANY, OF ROCHESTER, NEW YORK, 'A CORPORATION OF NEW. YORK.

'rns'rrne ELECTRODE.

Application filed January 25, 1924. Serial No. 688,486.

This invention relates to electrodes of the I kind used for testingelectric apparatus for defects such as short-circuits, and defective insulation. For this purpose it is customary to use manually operated electrodes which are connected with a source of electricity, i-n series with a lampor other indicator, and thetests are made by touching the contactmembers of the electrodes to the commutatorbars, terminals andother parts of the apparatus under test;

For the-purpose necessary to use high that accidental contact of the testingin question it is often electrodes with the person'of the user or with other conductors may cause serious shocks or discharges, and the electrodes musttherefore be handled with great caution. 5

The. object of I the present inventionis to provide means. whereby the contact-members of the electrodes are so shielded that accidental contacts are rendered. "practically impossible, while at the'same time the use of the electrodes is not made. in any degree inconvenient. To this end it' is proposed to provide a testing-electrode with an'insulat- .contact member whenever the electrode is not in actual use, but which is automatically withdrawn and held sequence of the act of for the purpose of using it;

' The idea in question may be embodied in out of the way in convarious ways, but the preferred embodiment is illustrated in the accompanying drawings, inwhichz. 4. r I Fig. 1 is a-longitudin'al sectional view of a testing-electrode, with the parts in the posiend-elevation, I d Fig. 1-; and Figs.- 3 and 4 are enlarged sectional views on the lines 3-3 and in Fig. 1.

.In the illustrated electrode thec'ont-act- .member is a metal. rod 5 with a pointed end;

and'the. guard'has the insulating-material such as vulcanized-fiber.

. The electrode-is handled and controlled by i fiber 9r et g-mater el; is

STATES in the sleeve .12 and it passes through the an 'electromotiveforce so conductor 15 has its conductive core soldered screwed .home the cable 15 is firmly gripped 'eration the bushing 18" is pressed against a is in position to guard the members are grasped they grasping the electrode g of convenient form, and the electrode can tion occupied'when' not in use; Fig. 215 an looking from left to right inwhich it is shielded'by the guard; a spring formof a tube 6'of" lar guard of insulating-material; a contact- 1,650,779 PATENT OFFICE. v

rear end of the contact-rod 5, thus connectnng this rod with the grip-member 8. A coiled spring 13, attached to the rear end of the rod 5, serves both to retract the rod within the guard, and to connect it with an electric conductor. A metal nipple 14 is screwed into the rear end of the guard-tube 6, and a cap 16 is threaded upon the rear end of the nipple, this cap being of insulatingmaterial. A loose metal bushing 18, with a conical rearwardly-opening socket, is enclosed by the cap, and a flexible cable or or otherwise connected with this bushing. A sphtconioal bushing 17 cooperates with thebushlng 18-, so that when the cap 16 is and clamped in place. By the same opcross-pin 19 to'twhich the rear end of the spring 13 is attached, thus completing the conductive connections between the contactrod 5 and the cable 15.

When the electrodeis not in use the spring acts to hold the contact-rod retracted withi in the guard, as shown, but when the grip-- v are thereby drawn together, thus sliding the rod v'lt'orwardly so that its end protrudes from the uard. In this position the two grip-members constitute substantially a single handle be used precisely the same as the ordinary unguarded electrode. The moment the electrode is dropped or laid down, however,'the contact-rod is automatically withdrawn into a position of safety.

The invention claimed is: 1. -A testing-electrode comprising: a guard; a. contact-member movable, relatively to the guard, into and out of a position in tending to move the contact-member into shielded position; and grasping-means, suit- 1 able for manipulating the electrode, con-v nected with'the guard'and the contact-member and movable, in consequence of being ed in the hand of the user, to cause movement of the contact-member into erative, unshielded position.

2. A testing-electrode comprising: a; tuburod slidably mounted. in therguard; a spring tendi g o re ract he con 4 trod m, 1 1* guard; and a handle connected with the rod and movable in consequence of being grasped in the hand of the user, to cause the rod to protrude from the guard.

3. A testing-electrode, as set forth in claim 2, in which the said handle'comprises two grip-members attached, respectively, to the guard and the contact-rod and movable toward each other when grasped.

4. A testing-electrode comprising: a tube, of insulating material, with a transverse slot ,near its rear end; a contact-rod 'slidable within said tube; a sleeve slidable upon the outside of the tube; a pin connecting said rod and sleeve through said slot; a grip member projecting laterally from the sleeve;

a second grip-member fixed to the tube; and a spring for movmg the contact rod in a direction to retract it within the tube and to separate the grip-members.

' 5. A testing-electrode comprising: a tube tube of insulating material; a contact-rod normally housed, at its forward end, within said tube but slidabl'e therein to cause said end to protrude from the tube; a grip-member rigidly attached to the tube and extending substantially at a right angle therefrom;

a member attached to the rod, slidably:

guided by the tube and provided with a second grip-member substantially parallel with the first said grip-member; and a spring interconnecting the tube and the slidable members and acting to retract the rod within the tube.

ANTHONY F. WILLIAMS.

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