US1174618A - Spark-plug and method of forming the same. - Google Patents

Description

` A. SCHMIDT. SHARK PLUG' AND METHOD OF FORNHNG THE SAME. APPLICATION FILED AUGJT, 1913.

1,174,61S- Patented Mar. 7,1915.

UNITED STATES ALBERT SCHMIDT, 0F FLINT, MICHIGAN, SSIGNOR TO CHALIGN GNTN CCNE' fil/HY,

OF FLINT, MIGHGAN, A CORPGRATSN GLF MCHGN.

SPARK-PLUG AND METHOD 0F FORMING THE SAME.

Application le August 21, 1913.

To all whom t may concern:

Be it known that l, ALBERT SCHMIDT, a citizen of the Republic of France, residing at Flint, in the county of Genesee and State of Michigan, have invented certain new and useful Improvements in Spark-Plugs and Methods of Forming the Same, ot which the following is a. specification, reference being had therein to the accompanying drawings.

The invention relates to spark plugs, and has for its object the simplilication of the method of manufacture and reduction in cost or" same.

ln the present state of the art, it is usual to form spark plugs with an outer metallic easing having a hexagonal portion for engagement of a wrench and an integral threaded nipple of reduced diameter for engagement with the aperture in the engine casing. lt is also usual to provide a shoulner within the metallic casing, against which the insulator bears, and a threaded bushing between the insulator and the case for hold ing the former to its seat upon said shoulder.

lilith my improvedv construction the threaded bushing may be entirely dispensed with by forming a threaded'engagement loetween the nipple portion and the hexagonal portion of the casing. Furthermore, the construetionlis one which may be manuvfactured vby a different method, viz. one in which the hexagonal and nipple portions are cut .from separate pieces oi' stock, wherehy waste is eliminated.

ln thepdrawings: Figure l is a central longitudinal section through the easing ot the spark plug, showing the insulator secured thereto; and Fig. 2 is a perspective view of the two-memhers of the casing detached, and illustrating the manner in which they are out from the stock.

With my improved method of manufao4 ture, I proceed as follows: A har of hei:- ag'onal stockof suitable dimensions, indicated by dotted lines at A, Fig. 2, is bored, internally threaded and 'otherwise 'fashioned to form the member l5. This ine-ailier Specification of Letters Patent.

relation.

Patented Mar. i2

Serial No. 786,601.

H being placed between the should .l on this insulator and an opposed sh der l termed by the inner end oi' the t* lf desired an inner bushing may he placed between i the member i3, after which ne n'iemhers B and l" are relatively rotated to clamp the shoulder l upon the shoulder lVhen the parts are thus assembled, ay 'lo spark plug is formed which dispenses 'with the usual threaded bushing, and which is in every way as strong and gas proof.

The nipple is secured into the engine easing hy engaging the hexagonal portion 'with the wrench or other tool, and to prevent relative movement of the members B and F". some loc such a set screw L is r these parte in fixed The oost' ot the construction reduced, both hy reason ot the method at manufacture and amount et stool-1 which is wastes.

lt will he noted that with the. tion or" plug as describen inserted the metallic ci side and bears against an upon said ca heretofore quires ado device for securing in position.

What claim a." my invent-ion is:

ola. casing comprising' con nipple portion adapted easing, and aal separat-e members navto engage an e'Y portion,

ing a. threaded engagement with each other, sadpolygonal portion forming the head for said nipple portion, a locking means to prevent relative movement of said members, and an insulator clamped between said Y members.

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