US1606620A

US1606620A - Spark plug

Info

Publication number: US1606620A
Application number: US19822A
Authority: US
Inventors: Finch George
Original assignee: AXEL W MEIER; CLINTON MCGREGOR; MARION SISCO; T M GULLICK; VERLIN K AGAL; WILLIAM M SISCO
Current assignee: AXEL W MEIER; CLINTON MCGREGOR; MARION SISCO; T M GULLICK; VERLIN K AGAL; WILLIAM M SISCO
Priority date: 1925-04-01
Filing date: 1925-04-01
Publication date: 1926-11-09
Anticipated expiration: 1943-11-09

Description

Nov. 9 1926.

G. FINCH SPARK PLUG Filed April 1. 1925 nch.

MMMZ 1 Patented Nov. 9, 1926.

UhllThU STATES ater GEORGE FINCI-I, OF LONG BEACH, CALIFORNIA, ASSIGNOR, BY DIRECT AND MESNE A EiE-GNIVIENTS, OF TWO AND ONE-HALF PER CENT TO AXEL W. MEIER, FZFTEEN PER GENT TO VERLIN K. AGAL, TVJO PER- CENT IO CLINTON MGGREGOB, ONE AND ONE- IIALF PER CENT TO WILLIAM M. SISGO AND MARION SISGO, AND FOUR PER CENT TO T. M. GULLIOK, ALL LONG BEACH, CALIFORNIA.

seam: PLUG.

Application filed April 1,1 1925. Serial No. 19,822.

This invention relates to improvements in spark plugs.

The primary object of the invention is to provide an improved spark plug having a hollow central electrode and a check valve therein, whereby air may be. admitted through the hollow electrode to the interior of a cylinder of an internal combustion engine. The admission of air in thismanner not only serves to re'duce'the partial vacuum formed in the cylinder during the suction stroke, but also provides for a more complete combustion therein, and will especially cause a complete combustion about the electrodes of the spark plug so as to keep them dry and clean.

it further object of the invention is to provide a spark plug having a core formed of insulating material in which is disposed a central electrode, and to provide an attaching means for fastening an electrical conductor to the spark plug, which attaching means is disposed in spaced relation to the central electrode so that a spark gap will be formed upon the spark plug between the points of its electrodes and also between the fastening means for the electrical conductor and the central electrode.

lVith the foregoing and other objects in view which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had tothe accompanying drawings for an illustrative embodiment of the ing means which is'adapted to be associated invention, wherein Figure 1 is a side elevation of the im proved spark plug; F 2 is a vertical section taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a perspective view illustrating the central hollow electrode;

Fig. is a perspective view of the cap or valve seat which is mounted upon the central electrode;

Flg. 5 1s a perspective new of the retalnwith the valve seat shown in Fig. 4 for maintaining the ball adjacent its seat; and

Fig. 6 is a horizontal section taken substantially on the line 6-6 of Fig. 2.

Referring to the accompanying drawings wherein similar reference characters destoward the central electrode.

ignate similar parts throughout, the improved spark plug consists of a'body 10 provided with an annular flange 11, which body is threaded exteriorly below the flange, as indicated at 12. A shoulder 13 is formed upon the interior of the body, and the body is interiorly threaded, as at 14, above the shoulder. A core '15 having a bore 16 formed therein is provided with a shoulder 17 adapted to engage the shoulder 13 upon the'body 10. The core is maintained within the body 10 by means of a gland or sleeve 18 which is adapted to be threaded or screwed into the body about the core above the shoulder 17.

The body 10 is provided with an annular grounded. electrode 19, which extends inwardly from the bottom edge of the body The central electrode is hollow and is shown at 20 as consisting of a small section of seamless tubing which has formed upon its lower end a tip 21 having lateral apertures or passages 22 which communicate with the interior of the tubing. The tip 21 also provides a point 23 which is disposed adjacent the end of the grounded electrode 19. The tip 21 provides a shoulder upon the electrode and a sleeve of insulating material 24 is disposed about the central electrode about the aperture 29 extends from the groove inwardly into the chamber 30 in which the ball 27 is disposed. A. ring 31 formed of spring wire or the like has one end bent radially inward, as indicated at 82.- This ring is adapted to be placed about the cap and occupy thegroove 28 with the end32 extending through the aperture 29 into the chamber below the ball 27 so as to maintain the ball adjacent its seat, and thus prevent the ball from falling and closing the bore 33 which is formed in the central electrode. The cap 25 may have a flange 34 formed ill) adjacent its top which rests upon the top of the core 15. It will be understood that by tightening the cap 25 upon the electrode 20, the electrode will be rigidly held within the core 15.

Upon the top of the core there is mounted a second cap having a stem 36 extending upwardly therefrom and which is exteriorly threaded to receive a thumb nut 37. An aperture 38 is formed in the stem 36 and permits air to enter therethrough past through the aperture 26 and to be drawn downwardly through the bore 33 ant the lateral passages 22. It will be noted that the cap is disposed in spaced relation tothe cap so as to form a spark gap between the cap 35 and the central electrode. The thumb nut 37 serves as a fastening means for connecting an electrical conductor, such as a wire, to the spark plug.

The operation of the spark plug is as follows: Upon the downward or suction stroke of the piston, a partial vacuum is formed in the cylinder. Air is drawn through the aperture 38 and escapes past the check valve provided by the ball 27 and flows downwardly through the central electrode. Upon the other strokes of the piston in which pressure is developed within the cylinder, the ball check valve 27 is held against its seat, so as to close the aperture 26. The tip 21 is preferably formed of Monel metal, so that it cannot be easily burned. By using the mica sleeve 24:, the expansion of the central electrode is taken care of, as the mica is capable of being slightly compressed and in this manner the expansion of: the central electrode will not crack the core 15 which is preferably formed of porcelain or the like. By providing the spark gap between the cap 25 and the cap 35, the electric current is caused to jump between the caps and also between the electrodes. The spark gap between the caps serves to control the current when of high voltage. It the current is of too great voltage, the spark gap tends to break it down.

On the other hand, if the current is of lowv voltage, it tends to build up before jump ing the gap, and in this manner a very eflicient spark plug is produced. The break ing of the vacuum in the cylinder of an internal combustion engine reduces the pumping of the oil, and the additional supply of oxygen derived from the admission of air aids in causing a complete combustion of the fuel within the cylinder. By the use of the mica sleeve 24, if the porcelain core 15 should become cracked, a short across the plug is prevented, which might otherwise occur by the creation of the spark between the central electrode 20 and the body 10 or the gland 18.

It will be understood that various changes in the detail of construction may be made without departing from the spirit or'scope of the invention as defined by the appended claims.

I claim:

1. A spark plug having a core formed of 1 second cap having an upwardly extending stem in which a passage is formed which is also in alignment with the bore in said electrode, and means associated with said stem for securing an electrical conductor thereto.

2. A spark plug having a core formed of insulating material, a central electrode disposed within said core, said electrode having a bore extending longitudinally therethrough, a cap threaded onto the upper end of the electrodehaving an aperture therethrough in alignment with the bore in the electrode, a valve seat upon the under side of said cap, a ball disposed within said cap adapted to seat upon said seat, means for maintaining said ball adjacent said seat, a second cap mounted upon said core in spaced relation to the cap on the electrode, said second cap having an upwardly extending stem in which a passage is formed which is also in alignment with the bore in said electrode, means associated with said stem for securing an electrical conductor thereto, the bottom of the electrode being provided with a tip having lateral passages therethrough communicating with the bore in the electrode and providing a point for the electrode, and a mica sleeve disposed between the electrode and the core.

In testimony whereof I have signed my name to this specification.

GEORGE FINCH.