US914540A - Spark-plug. - Google Patents

Description

F. J. WATT.

SPARK PLUG. APPLICATION Hum SEPT. 9,1908.

Patented Mar. 9, 1909.

9 10 Fig. 8. 13% 3.

WITNESSES: INVENTOR 0mm 00. Frank J. Watt a 2%. 99W By ATTORNEY/5' UNITED STATES PATENT oFFioE.

FRANK J. WATT, OF DETROIT, MICHIGAN.

SPARK-PLUG.

To all whom it may concern:

Be it known that I, FRANK J. WATT, a citi- I zen of the United States of America, residing part of-the bushing and the nipple.

at Detroit, in the county of Vi ayne and State of Michigan, have invented'certain new and useful Improvements in Sp ark-Plugs, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to spark plugs for explosive engines, and more especially to means therein whereby leakage and breakage from unequal expansion is avoided, and the construction greatly simplified.

The invention consists in the matters hereinafter set forth, and more particularly pointed out in the appended claims.

In the d ti'ally in elevation and Specification of Letters Patent. Application filed September 9, 1908.

i i i i i I i i i i Patented March 9, 1909. Serial No. 452,245.

The head is proportioned to leave an annular air space between it and the insulating bushing. The upper projecting end of the stem is screw-threaded for a clam ing nut 9 which bears against a spring was or 10 and soft washer 11 of asbestos or the like. The spring washer has a plurality of inner arms 12 bent alternately in opposite directions and a solid rim. A ca) 16 is seated on the washer rim over the camping nut and a hand nut 13 forming with the cap a binding post is placed on the stem outside the cap.- There is a sparking terminal 14 on the nipple and an axial one 15 on the stem in operative relation thereto. By this arrangement, the insulating bushing is held in place without the use of an outer clamping collar or cap, as in the rawiiigs, Figure 1 is a view, par-i usual construction, and is free to expand partially in section of without liability to fracture.

The stem is yieldingly seated against the inner bushing a spark plug embodying features of the invention. Fig. 2 is a view in detail of a spring by the spring washer so that expansion or conwasher. Fig. 3 is a view in section of the traction does not affect it. Furthermore, Washer. the joint between this bushing and the stem screw-threaded portion, a washer 5 of pro er material insuring a tight joint and there eing an annular air space between the lowfiar T e ead of the bushing extends well above the nipple and is enlarged to overhang and protect the nipple rim. The axial aperture of the bushing is counterbored from the lower end and a metal bushing 6 cemented therein or otherwise pro of the bushing 6 eing screw-threaded, corrugated or roughened to anchor it firmly in the cement which adheres closely to the unglazed inner surface of the porcelain. The lower end of the bushing 6 is turned or faced off square.

A metal stem 7 extends axially through the bushing 3 and has'a head 8 shouldered to seat itself closely on the lower end of the inner bushing and form a tight joint therewith.

erly secured, the periphery I head is readily made air tight by roper dressing of the metals, the diflioulty of making a close fit between metal and the vitreous, irregularly surfaced insulating bushing being avoided.

hat I claim as my invention is 1. A spark plug for an explosive engine comprising a tubular metal nipple, a bush ing of insulating material screw-threaded into the iii ple, a metal bushing secured in the bore of the insulating bushing mediate its ends, a metal stem extending through the insulating bushing having a head seated on the inner metal bushing, a spring Washer on the stem, a clam ing nut foroin the washer against the insulating bushing liead, a terminal on the stem and one on the nipple in operative relation thereto.

2. A spark plug for an explosive engine comprisin a tubular metal nipple, an insulating bus ing of refractory material screwthreaded into the nipple having a counterbored lower end, a metal bushing seated in the counterbore, a metal stem extending through the inner bushing having a head ada ted to be seated on the end of the inner busliingand a screw-threaded upper end extending above the insulating bushing head, a spring washer on the stem and bushing head, a c'lamping nut on the stem engaging the spring washer, a cap on the stem over the clamping nut bearing against the Washers, a

' {terminal on the stem osite directions a clamping nut on the stem eating a t: the spring arms, a ca over the nut seated on the rim, a nut on t e stem outside the cap, a terminal on the head of the stem, and a terminal on the nipple in operative relation thereto.

5. A spark plug for an explosive engine comprising an lnteriorly screw-threade a ternately in op on the stem beyond the ca the lower end of the nipp e and ead. 3. A spark plug for an explosive engine" comprising an interiorly screw; threaded metal nipple, an insulatmg bushing of refractory material having an exteriorly screwthreaded portion engaging the nipple screwhand nut minal on throu h the mner ada te to be seated bus ing and a screwabove the ininetal stem 'extendin lating Washer g head on the end of the inner threaded upper end extending sulating bushing head, an on the stem and bushing msu head, a spr ng threads, a lower portion of less diameter than metal nipple, an insulating bushing of rethe nipple extendin concentrically therefractory material having an exteriorly screw throug and a hea projecting above the threaded portion engaging the nipple screw- 1e, a metal bushing permanently secured threads, a lower portion of less diameter than n e insulating bushing mediate its ends, a the hi ple extending concentrically there metal stein extendingthroughtheinnerbushthroug and a hea projegting above the lng havin a eadadapted to be seated on nippnle', a metal bushing per anently secured the end of the inner bushing and a screwin t e insulating bushing mediate its ends, a

washer on the insulating Washer, a clam ing threaded uppelrk end extending above thoinnut on the stem engaging the spring was er, sulating bus g head, a washer of insulating a ca on the stem overthe clamping nut material on the upper end of the bushing, a bearing against the washers, a hand nut on 'sprin washer having a solid rim an inner comprising a tubu the stem v stem head,

the upper end rim and inner radial spring arms beyond the cap, a terminal on the alternately in oppolower end of the nipple, and a terminal on the 4. A spark plug for an explosive engine ar metal nipple, abushjng of insulating material screw-t the nipple, a metal bushingsecured in-the bore ofthe insulating bushing mediate its ends, a metal stem extending through the insulating bushing having a head seated on the innernietalbushing, a spring washer on of the bushing having a solid bent alter- Witnesses; O'r'ro FJBARTHEL, C.R.;STIOKNEY.\

on the stem two Witnesses.

FRANK J. WATT.

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