US1465978A - Sparking plug - Google Patents

Description

5 FISHER ET AL SPARRING PLUG Flled March 30 1920 qk S i Patented Aug. 28, 1923.

STANLEY FISHER, '01 EALING, AND WINWOOD PRIDDEY, OF MARYLEBONE, LONDON, ENGLAND.

'sranxmo PLUG.

Application filed March 30, 1920. Serial No. 369,899.

new and useful Improvements in Sparking- Plugs, of which the following is a specification.

This invention relates to sparking plugs of the kind. having the central portion readily removable from the threaded base or outer portion for the purpose of cleaning and adjusting the sparking points or of substituting a new central portion for an old defective one but held in position with sufiicient pressure to maintain a gas-tight joint bymeans of an adjustable member which is independent of or separate from the removable central portion.

According to the present invention, the adjustable member is formed with a .slotted flange and may have interposed between it and the central portion a retaining ring or the like. This ring or the central portion itself is formed with lugs or projections which engage in corresponding slots in the base portion of the plug and the slots in.

the flange of' the adjustable member are formed to correspond with the slots in the base portion of the plug. When these slots are caused to coincide or register, the central portion consisting of the electrodes and insulator, together with the retaining ring when such is employed may be removed from or inserted into the base portion of the plug as a separate self-contained unit without detaching the adjustable member. The latter may be in the form of a cap connected to the base portion of the plug by screw threads or any other suitable joint. \Vhen the removable central portion is inserted in place, a partial turn of the cap causes the flange ofthe latter topress downwards upon the retaining rinand exert pressure on the central portion or compressing a suitably arranged washer or wasliers and making a gas-tight joint. 'In order to facilitate the removal and re-insertion of the central portion a stop maybe provided to ensure the slots are in register. g

In order that the said inventionmay be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawings,'in which c Figure 1 is an elevation, and

Figure 2 a vertical section of the improved sparking plug.

Figure 3 is an elevation partly in section, and

Figure 4 a plan of the base portion of the plug that screws into the engine cylinder in the usual manner.

- Figure 5 is a vertical section and Figure 6 a plan of the retaining ring.

Figure 7 is a vertical section, and

Figure 8 a plan of the locking member or cap.

Figure 9 is an elevation partly insection of the central portion comprising the two electrodes, insulator and retaining ring.

Figure 10 shews in vertical section 'a modified form of the device, in which the negative electrode, instead of being in the form of a thimble, is a plain rod passing through the plug body and fitting tightly into a hole drilled in the part d.

Figure 11 is an elevation of a modified .rial such as orcelain, fused quartz, mica and so forth. 0th electrodes are preferably tipped with nickel inthe neighbourhood of their sparking points. d isthe retaining ring which is formed with two diametrically opposite vertical lugs 6. These parts,.a, b, c and d constitute the removable central portion. The ring d is shown cut away internally to allow the insulator 0 to have as much cooling surface in contact with the air as possible. f is the base portion of'the sparking plug formed with vertical slots 9 corresponding to the lugs e. The portion, f, usual, has a standard thread at its lower end for screwin into the cylinder of the engine and has t e usual hexagonal portion upon which a spanner may be used. is is the flanged cap. The up er end of the portion f is formed with an external square screw-thread h, for the reception of a similar thread on the cap k whichwhen inplace presses upon the ring (1 This cap is has,

plug for inspection or repair.

1 compress-the washer n thus obtaining a gastight joint. A washer m is also pressed be tween the ring d and the insulator 0.

o is a stop pin which is mounted in a hole in the base portion f and pressed upwards by' a spring 10 against an inclined 'face 0 on the cap k. The cap 70 may be unscrewed until it is stopped by the vertical surface or shoulder 1- on the cap coming against the pin 0. Then the slots 9 are in register with the 2 slots Z and the central portion may be withsulator c.

drawn with the ring d. Any other suitable form of stop may be used for this purpose.

The central electrode a is square in crosssection and fits in a square hole in the in- Tt makes-a gas-tight joint at the packing s when the nut t is screwed down and cannot rotate when the terminal nut u is tightened. up. V The electric conductor is gripped between the nuts t and u. The lower end of the said central electrode a is made ball-pointed so that any drops of oil which tom thereof instead of becoming corbonised between the sparking points. The

earthed electrode 6 is in the formof a thin being spun or pressed into a small groove 0 in the insulator a or instead it may have a small inward protuberance suchas a depression made by a punch which protuberance fits into a shallow bayonet groove in the lower part of the insulator c. The electrode 5 has internally projecting parts at m which form its sparking points and are of proper size to provide the requisite spark gap between them and the central electrode.

Referring to Figure 10, in this modification the insulator c is made in two parts 0 and c, the latter being added after placing the ring (Z in position. ll 'he negative electrode 7) is a rod fitting tightly into a hole in the ring (Z. The cap is may be provided with a short laterally extending handle 3 where preferred.

Referring to Figures 11 and '12. a ring 2 below the ring 03 is employed to secure the negative electrode 6, the latter fitting into a Lea ers perforation in a protuberance on the ring 2, and theinsulator being grooved to accommodate the" protuberance .on the ring and also the'part 0f the rod which projects from the ring.

Various modifications may be made in the ternal lugs and separated from'the central electrode by a number of mica wrappings. There are then more mica washers and the whole is firmly heldby the top nut.

Yet again, the cap is maybe externally screw-threaded and may screw into the base portion f or again it may be secured thereto by means of a bayonet or any other appropriate form of joint suitable for this purose. a

p The removable central portion of the sparking plug consists essentially of the insulator the rin d and the two electrodes,

a b and'one o 'ect of the invention is to render thlS POItIOII simple, cheap and e sy to manufacture. In using thesparking p 11g,

the base portion f and the cap k do not require tobe detached in order to remove thecentral portion for inspect-ion'or'repair.

What we claim and desire to secure by Letters Patent of the United States is may reach it Will tend-to drip from the bot- 1. In a sparking plug for an internal combustion engine, a base attachable to the engine cylinder, a removable portion comprising an insulator, electrodes and projecting lugs, a cap adjustably mounted on the said base and having a flange normally engaging the said projecting lugs, the said flange being provided with slots adapted to be brought into register with the said projectin lugs for'the purposes specified.

2. n a sparking plug for an internal combustion engine, a base attachable to the engine cylinder, a removable portion comprising an insulator, electrodes and a retaining ring having projecting lugs, a ca adjustably mounted on the said base an having a flange normally engaging the said projecting lugs, the said flange being provided with slots adapted to be brought into register with the said projecting lugs for the purposes specified.

3. In a sparking plug for an internal combustion engine, a base attachableto the engine cylinder, a removable portion comprising an insulator. electrodes, one of which electrodes is ball-pointed and projecting lugs, a cap adjustably mounted on the said base and having a flange normally engaging the said projecting lugs, the said flange bein provided with slots adapted to be brought into register with the said projecting lugs for the purposes specified.

4. In a sparking plug for an internal oombustion engine, a base attachable to the engine cylinder, a removable portion comprising an insulator, electrodes the earthed electrode being fitted to the inner end of the said removable portion and provided with an internally projecting part, and projecting lugs, a cap adjustably mounted on the said base and having a flange normally engaging the said projecting lugs, the said fiangebeiug provided with slots adapted to be brought into register with the said projecting lugs for the purposes specified.

5. In a sparking plug for an internal combustion engine, a base attachable to the engine cylinder, a removable portion comprising an insulator, electrodes and projecting lugs, a nut adjust-ably mounted on the said base and having a part normally engaging the said projecting lugs, the said part being provided with slots-adapted to be brought into registration with the said projecting lugs for the purpose specified.

STANLEY FISHER. WINWOOD PRIDDEY.

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