US2071254A - Spark plug - Google Patents

Description

c. G. CRAMER- SPARK PLUG Filed July 1, 1956 III I (YR/L G. (FAME/P,

Patented Feb. 16, 1937 UNITED STATES PATENT OFFICE SPARK PLUG Cyril G. Cramer, Binghamton, N. Y. Application July 1, 1936, Serial No. 88,457 2 Claims. (01.123-169) My invention relates to spark plugs and mpre particularly to a plug so constructed as to pro: duce a plurality of sparks, and it consists in the constructions, arrangements and combinations herein described and claimed.

It is an object of my invention to provide a spark plug in which the positive electrode of the plug is formed as a series. of spark-gaps, a spark occurring at each of the gaps, thereby assuring" perfect ignition of the fuel.

It is a. further object of the invention to provide a plug which may be readily assembled and dismantled for cleaning. a

It is a still further object of the invention to provide a plug in which the plug shell, the insulater and the plug head are so formed interiorly as to produce anignition chamber.

Additional objects, advantages and features of invention will be apparent from the following description considered in conjunction with the accompanying drawing, wherein,

Figure 1 is a vertical sectional view of a plug constructed in accordance with my invention.

Figure 2 is a cross section on the line 2- 2 of Fi ure 1.

Figure 3 is a plan view of an insulator employed in the plug. r g

In carrying out my invention I provide a metallic shell III having a threaded nipple II, atone end, for securement of the plug in an engine head, as is customary. The upper portion of the shell is preferably hexagonal in cross section,-for ready manipulation by the use of a wrench.

The nipple I I includes a bore I2, the surface of "which is flared outwardly as at I3, and thence extended in a horizontal plane forming an annu-, lar seat I40 From the seat I4 the surface extends longitudinally of the shell I0, as at I5, forming an annular well, being interiorly threaded at its upper termination for reception of a packinggland I6.

Upon the seat of which stops flush with flared outer circumference of which is slightly less the annular well. An annular, insulator I8 is positioned upon the gasket I'I, anda similar gasket I9 is disposed upon the upper face of the insu- I4, I provide a gasket I1, the bore wall I3, and the lator against which the gland I3 may engage.

The bores of the insulator and the last named gasket are the same as the gasket II so that a smooth uninterrupted surface is presented, and

. the gland I6 is undercut as at 20 and aligned with the bore of the gasket I 9. It willthus be seen that a chamber, generally indicated at 2|, is provided which functions as a firing chamber.

than

. a suitable point is provided with a shoulder 23 is of slightly less length stroke of the pistons of tended inwardly of the forming a seat for the enlarged portion 24 of an elongated insulator 25. A screw-threaded gland 26 is engaged. with the threads of the bore 22 for maintaining the insulator 25 in position, andpreferably packing rings 21 are employed in conjunction with the enlargement 24, the shoulder 23 and gland 26, to effect a gas-tight connection.

The insulator 25 includes an electrode 28, the lower end of which terminates approximately medially of the height of the insulator I8, for a purpose as will presently appear, and the upper end of the electrode includes a binding screw and nut 29 whereby connectionmay'-be made with a wire of an ignition system.

Referring now to Figures ing; particularly, the shell II] has a lug 30, ex-

annular'well I adapted to engage within a complemental notch 3| formed in the outer face of the insulator I8. The lug 30 than-the depth of the notch 3|, thusstopping short of the inner wall 2 and 3 of the draw of the notch.

An electrode 32 is embedded in the insulator I8 extending axially therefromand stops short of the electrode 28' a necessary distance to form a' spark gap. The insulator I8 further includes; a series of electrodes 33, suitably spaced in annular formation, each of which comprises a right angularly disposed arm 34, extended in the direction of the next adjacent arm, but stopping short of contacting relation therewith. Thus, it

will be apparent that a spark gap is formed between each arm '34 and the next adjacent electrode. Any desired number of electrodes 33 may be included but the last electrode designated 33a. must be positioned so as to align medially of the notch 3|. This latter electrode must project a short distance inwardly of the notch so as to readily contact the lug 30 in order to complete the circuit'through the plug.

The operation The operation will be readily understood from the following description, assuming that an engine is equipped with my plugs. The suction an engine will draw in the explosive mixture; the next action occurring will be the compression of the charge in the compression chamber of the engine, but compression of the gas also occurs in the chamber 2| of the plugs. .Thus there is a highly ignitible mixture around the electrodes 28, 33 and 33a. When will occur between each electrode, thereby producing a circular formation of fire which is highly efiective upon the explosive mixture in the explosive space of the motor, consuming the mixture thoroughly, thereby causing the power stroke. Then the exhaust stroke occurs, as customary, completing the cycle of the engine.

It will be apparent that with the use of my plug, the motor as well as the plug itself will be kept free of carbon accumulations, due to the efi'icient and ample spark producing thorough burning of all combustible fuel as well as residue which may be present. Also by providing a plug with a series of sparks a quicker starting of a motor is made possible as Well as efi'ecting economy in fuel consumption and obviously produces increased power.

While I have shown and described a preferred form of the invention, this is by way of illustration only, and I consider as my own all such variations in construction as fairly fall within the scope of the appended claims.

I claim:

1. A spark plug having a casing, an insulator ring therein, a gland for securing the ring in position, said casing ring and gland having an interior structure defining a chamber, a positive electrode carried by the gland, said electrode termiignition occurs, it will be apparent that a spark hating medially of the. chamber, a plurality of electrodes mounted in the insulator ring disposed axially therefrom and spaced with respect to one another to define spark-gaps, one of said electrodes extending into close relation with the positive electrode to define a spark-gap, and one of said second named electrodes having contacting relation with the casing.

2. A spark plug comprising a casing having a Well medially thereof, an insulator ring seated in the well, a gland cooperable with the casing for securing the ring in position, said casing and gland having portions shaped for cooperation with the walls of the ring to define a chamber,

the periphery of said ring having an inwardly directed notch, a lug on the interior of the casing and projecting into the notch, a positive electrode carried by the gland, said electrode terminating medially of the chamber, a plurality of electrodes mounted in the insulator ring disposed axially therefrom, each electrode having a right angular portion stopping closely adjacent the next electrode to define a spark gap, the first of said electrodes extending into close relation with the positive electrode to define a spark gap, and the last of said second named electrodes having contacting relation with the lug of the-casing.

CYRIL G. CRAMER.

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