US1965534A - Ignition mechanism - Google Patents

Description

July 3, 1934 E. B. Nowosu-:LsKl

IGNITION MEGHANISM Filed Nov. 18. 1952 INVENTR. Edward NowoS/'e/skl' Patented July 3, 1934 UNITED STATES IGNITION MECHANISM Edward B. Nowosielski, Bloomfield, N. J'., assignor, by mesne assignments, to Eclipse Aviation Corporation, East Orange, N. J., a corpora-k tion of New Jersey Application November 18, 1932, Serial No. 643,285 3 Claims. (Cl. 12S-169) This invention relates to ignition devices for internal combustion engines, and particularly,4

though not exclusively, to ignition devices wherein a heating coil is included for rst heating the combustion chamber of an engine to expedite the attainment of ignition temperature, whereupon ignition is produced by means of a jump spark.

An object of the invention is the provision of a novel combined spark and glow plug of the type involving the use of a pair of electrodes separated by a small airgap, with one of the electrodes electrically connected to a glow coil of suitable resistance to produce high heat radiation. In one embodiment of the invention herein illustrated, the said electrodes, as well as the glow coil, are disposed in coaxial relationship, while in the second embodiment herein illustrated the glow coil and one of the electrodes are in coaxial relationship while the second electrode is disposed adjacent the rst, and, although forming a single unit therewith, is spaced therefrom by a slight distance which provides the desired air gap. p

Another object of the invention is to provide a combined spark and glow plug adaptedfor the above described purposes and embodying in its construction novel features of practical advantage, including novel means for housing the glow coil so that the coil and the leads thereto are protected from exposure to the products of combustion.

These and other objects and advantages of the invention will be more apparent from the following detailed descriptiomtaken in connection with the accompanying drawing wherein two embodiments of the inventionfare shown. It is to be expressly understood, however, that the drawl ing is for the purpose of illustration only, and

is not designed as a denition of the limits of,

the invention, reference being had for this pur-v pose to the appended claims.

In the drawing,

Fig. 1 is a longitudinal section through a device embodying the invention;

Fig. 2 is a transverse sectional view along the line 2-2 of Fig. 1'; and

Fig. 3 is a longitudinal section of the second embodiment above described. i "f Referring rst to the embodiment shown in Figs. 1 and 2, the invention is therein shown as incorporated in a compact, symmetrical unit having a shell portion 5 of current conducting material adapted to constitute the negativeelectrode of the plug. As shown, the shell 5 includes an upper polygonal portion 6 adapted for engagement by the usual socket type of wrench for attachment of the unit, and a central externally threaded portioniI 7 adapted to engage corresponding threads cut in a member 8 which, as' shown, has an integral extension 9 of suilicient length to receive and enclose substantially the entire length of the lower Unthreaded and thinner Wall section 11 of the shell. The member 8 may be a part of the engine cylinder or it may be an adapter member attachable to the engine cylinder by suitable means adapted to be inserted through the openings 13 and 14.

At its lower end the extension 9 is shown as provided with an inwardly extending portion 16 providing an annular ledge 17 on which a sealing washer 18 rests and is in turn engaged by a flange 19 formed on the sectionll of the rshell just above the spherical lower end 21 thereof. Preferably the lower end `21 is apertured centrally 75 as shown at 22 to` permit the lower end 24 of the positive velectrode 26 to project therethrough. Just above the lower end 24 the electrode is of a larger diameter, as indicated at 27, and the upper `surfaceof the enlarged portion 27 constitutes a seat andV support for a plurality of insulating discs 29 of gradually yincreasing diameter; the upper discsof the 'series being separated from the electrode byI the interposition of the usual insulating wrapper'Sl which surrounds almost the entire length of the electrode 26. A second series of insulating discs 34 surround the upper portion of the insulatingwrapper 31, and these are held in assembled relation' by the usual cap 36 having its upper surface countersunk as indicated at 37, to receive the upset end 38 of the electrode, while the lower set of insulating discs 29 are held in assembled relation by the provision of a sleeve 41 threadedly engaging the shell 5, as indicated at 42, the head 43 being separated from the head 6 of the shell 5 by suitable means 46.

The parts thus far described will be understood as functioning in the manner of the conventional K, spark plug to cause a spark to jump across the 100 air gap between-the lower end 24 of the positive electrode and the spherical end 21 of the negative electrode which, as indicated, is grounded on the cylinder wall through'its contact with the member 8, it being understood that a high ten- 105 sion lead is attached to the cap 38.

There remains to be described the novel manner in which the negative electrode 21 achieves the double function of conducting the high tension spark current and also the current which 110 y of the upper portion of the shell 5 from which point the lead 56 extends to a suitable source of current for energization of the coil.

The embodiment of the invention shown in Fig. 3 is substantially the same as that shown in Figs. 1 and 2 with respect to the construction of the spark producing portion ofthe unit, but differs in the construction of the heat radiating,

or glow coil, portion thereof. As shown in this embodiment, the glow coil 149 is wound about an insulating wrapper/'151 which in turn surrounds a center electrode 152, the upper end of which is threaded for reception of suitable means 153 by which the lead 156 from the source of current is attached. At its lower end the electrode is apertured to receive end 150 of the coil 149, the other end of the coil being'embedded in the downwardly extended end 159 of a nut 161, insulated from the electrode by reason of the interposition of the insulating wrapper 151'; the insulation with respect to the nuts 153 being effected by the provision of an insulating disc 163. As shown, the threaded end of the nut 161 engages the corre- VAsponding upper end of the shell 164, the latter -being disposed adjacent the shell 105 of the spark producing portion of the unit and, together with said shell 105, being received in an obliquely apertured base 167 which in turn is held fast to the cylinder wall by suitable means 168.

This second embodiment also differs from the embodiment rst described in that the lower end 124 of the positive electrode of the spark producing unit terminates adjacent the lower end 121 of the shell 164 and the latter constitutes the grounded or return electrode for both the high tension spark current and the heating radiating current passing through the glow coil 149.

While the embodiment of the invention shown in Figs. 1 and 2 is preferred for certain installations, and that of Fig. 3 for certain others, depending upon the conditions encountered and the service required, it`is to be understood that the invention may be embodied in other constructions differing from each of those shown, provided the essential features, as outlined in the broadest of the appended claims are maintained. For claims directed -to the embodiment shown in Figs.

1 and 2, reference to be had to my co-pending :'ipplicatirn filed June 2nd 1934, the claims in this application being directed to the embodiment Ain Fig. 3 only.

It will be noted that in both embodiments herein illustrated; the glow coil is effectively 'sealed and protected from contact with the products of combustion in the cylinder, and as a. consequency of this protection there is no danger of breaking down of the insulation separatingA said coil (andA the lead thereto) from the other current con` ducting parts of the plug. In the form of the invention shown in Fig. 1, the effective seal is assured by the provisionhof a washer 18 which is preferably made of copper or some material having the ductility and heat conductivity of copper so that the tightening of the nut 6 will insure a firm seating of the washer and prevent seepage of any of the products of combustion into the annular space occupied by-the coil 49. A high heat conductivity for the washer 18 is desired in order to provide effective radiation of the heat transferred from the grounded end 53 of the glow coil to the lower end of the extension 9, such heat transfer being to a largel extent by way the washer 18. In the embodiment shown in Fig. 3, the effective sealing of the chamber containing the glow coil 149 is assured by reason of the fact tha't the lower end 121 of the shell 164 is integral with said shell so that the only means of access to the coil containing chamber is by way of the opening at the upper end of said chamber and said opening is effectively sealed by the gasket indicated at Similar gaskets 172 and 173 prevent the escape to the atmosphere of any of the products of combustion; and as above stated, theintegral construction of the shell 164prevents any access whatever of the gases into the coil containing l chamber.

It will be further noted that in both embodiments there is one electrode common to both the spark producing and glow producing currents.

In the embodiments shown in Figs. 1 and 2, this v electrode is indicated by the reference character 21, while in Fig. 3 this common electrode is indicated by the reference character 121. In each embodiment this common'electrode is disposed in coaxial relationship with the glow coil, it being disposed within said coil in one embodiment, and surrounding said coil in-the other. It is to be understood, however, as above suggested, that changes may be made in the relative arrangement of partsl as well as in other features of construction and the method of installation.

What is claimed is: j r

1.'\In` a combined spark and glow plug, a pair of electrodes separated by an air gap adapted to be traversed by high tension current to produce ignition of the fuel charge, and means for heating the fuel charge prior to such ignition, said heating means comprising a current conducting coil mounted within one of said elecy-trdes, said latter electrode serving to protect said coil from Ithe deleterious effects of the products of combustion of the fuel y 2. In a combined spark and glow plug, a pair .of converging electrodes separated by an air gap adapted to be traversed by high tension current to produce ignition of the fuel charge, and means for heating the fuel charge prior to such ignition, said heating means comprising a current conducting coil, one end of which is in electrical con- A tact with one of said electrodes, and a third elec'.

trode extending into one of said converging electrodes to energize said coil.

3. In a combined spark and glow plug, a pair of electrodes separated by an air gap adapted

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