US1544630A - Spark plug - Google Patents

Description

July 7, 1925.

c. L. BRADEN Filed N 7, 19

m ,4 5 a M 2 Patented July 7, 1925.

UNITED STATES i A 1,544,630 PATENT OFFICE.

CLEMENT L. BRADEN, OF ANDERSON,'INDIANA.'

SEAR]! PLUG.

Application filed November 7, 1923. Serial No. 678,8?1.

To all whom it may concern:

Be it known that I, CLEMENT L. BRADEN, a citizen of the United States, residing at Anderson, in the county of Madison and State of Indiana, have invented or discovered certain new and useful Improvements in Spark Plugs, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention has for its object to provide a spark plug, for internal combustion engines, which will be of such construction that the lower part of the casing or shell of the spark plug, and which extends into the combustion chamber of the engine, will serve as a guard to prevent oil from coming in contact with the central electrode of the plug, as also to provide an eflicient spark gap construction and a heating chamber adjacent thereto, as will hereinafter more fully appear. I

The accompanying drawing is a vertical section of the improved spark plug.

Referring to the drawing, 12 denotes the spark plug shell or casing having an externally screw-threaded portion 13 to be screwed into the engine cylinder. The up per part of the casing or shell 12 is screwthreaded internally for the reception of a nut 14 by which the insulation member 15 is secured in place in the usual manner. The

positive electrode is in the form of a pin 16 provided at its top with a screw-threaded part on which the nuts 17 and 18 are mounted and by which the said electrode. is secured in place. The parts thus far described are or may be of any preferred or usual construction, and the novel features of the improved spark plug will now be described.

The lower part of the shell or casing 12 is' formed with an annular downwardly tapering thin part 19 preferably formed concave, as shown, and below the said tapering part is formed an outwardlyv extending flange 20, which is preferably curved, as shown. Within the wall 19 is a heating chamber 21. As is well known many spark plugs are fixed in the engine cylinders in inclined positions, and the construction just described serves as a guard to prevent oil from, dripping onto the positive electrode 16, such guard being more efficient, for the purpose ust referred to, when the spark plug is in an inclined position.

The inner lower end of the wall 19 is constructed as a thin inwardly extending flange 22 which serves as the negative electrode of the plug, the spark gap 23 being located between said flange 22 and the positive electrode 16. It will be noted that the wall of the chamber 21 is formed thin so that it will readily become heated and will thus serve to heat the chamber 21 so as to heat and dry out the gas mixture which may enter said chamber.

The bottom part of the casing, having the inwardly extending negative electrode flange 22 and the outwardly extending oil guard flange 20, is formed flat, as shown, so that oil will not readily, creep inward.

The positive electrode 16 is of a proper length to extend below the spark gap 23, so that any oil which might by any possibility come in contact with the said electrode will be below the spark gap and will thus naturally drip off the said electrode into the chamber of the engine cylinder. Thus this downwardly extending lower end of the positive electrode will serve as a guard for the negative electrode afl'orded by the flange 22.

From the foregoing it will be apparent that the novel construction above described of the lower end of the spark plug will serve as effective guards to prevent oil and carbon from lodging on the electrodes of.

the plug at the sparking or firing point, while the chamber above the spark gap will readily become heated to facilitate combustion of the gas, and only a dry mixture of gas can enter said chamber.

Having thus described my invention I claim and desire to secure by Letters Patent:

A spark plug comprising a shell or casing formed with a downwardly tapering lower ,part having a thin wall and a flat bottom,

said thin wall terminating in a thin, inwardly extending flange, serving as a negative electrode, and an outwardly extending flange serving as an oil guard, combined with a ositive electrode insulatingly sup ported in said casing and extending below said negative electrode flange, with a spark gap between said electrodes.

In testimony whereof I affix my signature.

CLEMENT L. 'BRADEN.

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