US2122160A - Resistor - Google Patents

Description

June 28, 1938. H R 2,122,160

RES ISTOR Filed Odt 26, 19:55

IN V EN TOR.

A TTORNEYS.

Patented June 28, 1938 UNITED STATES RESISTOR Harold C. Sherk, Erie, Pa., assignor to Eric Resistor Corporation, Erie, Pa., a corporation of Pennsylvania Application October 26, 1933, Serial No. 695,362

10 Claims.

The present invention is designed to provide a resistor of a form particularly advantageous in avoiding disturbances caused by spark circuits of automobiles in which it is desired to install a radio. In the present invention the resistor is so formed that it may be readily attached to the ordinary standard spark plug. With such resistors it is desirable to include a resistor element of sufiicient length and cross section to assure efficient and uniform operation and at the same time form a structure occupying small space and fully protected from outside contacts. It is also preferable to form the resistor so that it may be attached on the spark plug as close to the gap as possible in order to have as little conductor surface between the gap and the resistor as possible. In the present invention a comparatively long resistor element is provided with a convenient and small space and the structure as a whole is completely protected from outside disturbance. Features and details of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing as follows:

Fig. 1 shows an elevation of a spark plug with the resistor in place thereon.

Fig. 2 an enlarged view, partly in section, of the resistor.

Fig. 3 a section on the line 33 in Fig. 2.

Fig. 4 a section on the line 44 in Fig. 3.

Fig. 5 a plan view of the resistor element.

I marks a spark plug. This may be of any standard form ordinarily having an upper screwthreaded terminal 2 with the usual spark gap la.

The resistor has a sleeve 3 which is adapted to be screwed on to the upper end 2 of the spark plug. This sleeve is provided with a shoulder 4 and a nurled or roughened edge 5. An upper terminal B for the resistor has a shoulder l which is provided with a nurled, or roughened edge 8 and an extension 9 below the shoulder which is of the same diameter and concentric with the sleeve 3.

An insulating ring 10 is arranged around the sleeve and in contact with the shoulder 4. An insulating sleeve H is arranged around the sleeve 3 and extension 9 and has a flange l2 the surface of which opposes the ring It.

A resistor element 13, preferably of a molding composition, is in the form of a split ring. The ends of the split ring are plated with conductor material at H. Ordinarily this is provided by spraying a copper coating on the end of the ring.

A connector I5 is electrically connected with one conductor end M of thesplit ring and the sleeve 3. A similar connector it is electrically connected with the connector end 54 on the opposite end of the ring and this connector is electrically connected with the shoulder l of the terminal 6. Preferably an insulating separating piece I! is provided between the sleeve 3 and the end of the extension 9.

With the parts so far described in assembled position the parts are encased in a material, such as bakelite, and the assembly placed in a mold and a case I8 is formed in the closing of the mold setting of the bakelite under heat and pressure. The case so formed entirely encloses the resistor parts and secures these parts in assembly. In order to more definitely secure the terminals the nurled, or roughened surfaces 5 and 8 are provided which, as the bakelite, or encasing material is molded and subjected to pressure flows into the indentures formed in the metal terminals and thus assures a union. The element in the form of the ring gives a desirable length of resistor element in a very small space. The opening through the ring is utilized for the terminals and the whole assembly has a cylindrical form with the axis of the terminals as a center without obstructions and the bakelite completely insulates as well as encloses the element and parts from any accidental contact from without.

What I claim as new is:

1. In a resistor, the combination of a split ring of composition resistor material; separated and oppositely axially extending terminals for the ring; insulation for the split ring; and electric connections between circumferentially spaced portions of the ring and the terminals, said con nections being within the axially projected area of the ring,

2. In a resistor, the combination of a split ring of composition resistor material; separated and oppositely axially extending terminals for the ring concentric with the ring; insulation for the split ring; and electric connections between circumferentially spaced portions of the ring and the terminals, said connections being within the axially projected area of the ring.

3. In a resistor, the combination of a split ring of composition resistor material; separated and oppositely axially extending terminals for the ring, one of which is screw-threaded; insulation for the split ring; and electric connections between circumferentiallly spaced portions of the ring and the terminals, said connections being within the axially projected area of the ring.

4. In a resistor, the combination of a split ring of composition resistor material; separated and oppositely axially extending terminals for the resistor; connections between the terminals and circumferentially spaced portions of the ring; and means insulating and encasing the ring and connections comprising a case molded to the terminals and uniting the terminal and ring assembly, said terminals and connections being within the axially projected area of the case.

5. In a resistor, the combination of a split ring of composition resistor material; an insulating sleeve Within the ring; axially directed terminals extending into the sleeve; connections between the terminals and circumferentially spaced portions of the resistor ring; and a case secured to the terminals and enclosing the ring and connections and securing the parts in assembly.

6. In a resistor, the combination of a split ring of composition resistor material; an insulating sleeve within the ring; axially directed terminals extending into the sleeve; connections between the terminals and circumferentially spaced portions of the resistor ring; and a case molded to the terminals and enclosing the ring and securing the parts in assembly.

7. In a resistor, the combination of a split ring of composition resistor material; an insulating means comprising a sleeve within the ring and extending portions over the face of the ring; axially directed terminals extending into the sleeve; and connections between circumferentially spaced portions of the ring and the terminals.

8. In a resistor, the combination of a split ring of composition resistor material; an insulating means comprising a sleeve within the ring and extending portions over the face of the ring; axially directed terminals extending into the sleeve; connections between circumferentially spaced portions of the ring and the terminals; and a case secured to the terminals enclosing the ring and securing the terminals, ring and in sulation in assembly.

9. In a resistor, the combination of a split ring of resistor material; an insulating means comprising a sleeve within the ring and extending portions over the face of the ring; axially directed terminals extending into the sleeve, said terminals having shoulders extending over the insulation at the ends of the sleeve; connections between circumferentially spaced portions of the ring and the terminals and a case secured to the terminals enclosing the ring and securing the terminals, ring and insulation in assembly.

10. A resistance device comprising a molded block of non-conductive material, a hollow internally threaded terminal member embedded in one end of the block and having an open end, a second terminal member having an enlarged portion embedded in the block at its opposite end and provided with an integral threaded post projecting from the end of the block, a split annular resistance element within the block intermediate the embedded portions of the terminal members, and conductor elements connecting the ends of the split annular resistance element with the terminal members, said terminal members and resistance element being axially alined and said resistance and conductor elements being embedded in said block of non-conductive material.

HAROLD C. SHERK.

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