US2164591A - Radio shielded spark plug lead - Google Patents

Description

s 3939- I M. F. PETER$ ET AL 9 5 RADIO SHIELDED SPARK PLUG LEAD Filed Jan. 10, 1958 34 L/fl INVENTORS 25 W W m/QM;

Patented July 1939 -UNI'TEDSTATESD PATENT OFFICE 2.104.591 namo SHIELDED sraax PLUG LEAD Melville F. Peters, Beltsville, Md., and a. Harry Stone, Bound Brook, N. 5.

Application January 10, 1938, Serial No. 184,306

Claims. (cr es-14s) This invention relates to an improved structure of radio shielded spark plug lead for internal combustion engines.

As is well known, a shielded ignition system for 5 an internal combustion engine has comprised an are shaped structure embracing the engine shaft,

through which pass all the ignition conductors leading fromthe magneto to the spark plugs. Such are shaped structure serves, especially in in connection with radial engines such as commonly used on aeroplanes, to guide and support the conductors about the engine shaft and also constitutes a radio shieldabout them, and is commonly known as a manifold. At suitable points 15 on the manifold, conduits and conductors extend to the magneto-and also extending from the manifold at certain suitable'points are spark plug leads, to the various spark plugs, each of said spark plug leads comprising a. suitable conductor and a radio shielding conduit therefor.

The main-object of the presentinvention is to provide an eilicient and simple construction of spark plug lead.

'I'he conductors of spark plug leads are often injured by heat of the engine or otherwise so as to require renewal.

It is a further object of the invention to provide a spark plug lead whereof the conductor can be removed or replaced with minimum trouble,

delay and expense.

The renewal or replacement of a-radio shielded spark plug lead has heretofore involved a joint permitting the disassembly of its conduit from the manifold. This detachability however involves the insecurity of connection of such structures and affords a joint at which water leakage may occur. Moisture within the conduit cannot be tolerated for obvious reasons.

It is therefore a further object of the invention to provide a spark plug lead wherein the conduit may be permanently connected with the manifold and the conductor nevertheless be removed or replaced.

' Other and ancillary objects of the invention will appear hereinafter.

In the accompanying drawing which illustrates plug end of the lead of Fig. 1, the remainder being broken away; 7

Fig. 3 is an axial section to the same scale as Fig. 2 of the manifold end of the spark plug lead, the remainder being broken away. 5

Referring to the drawing, the conductor-encasing longitudinally arc-shaped manifold I of metal, has at suitable intervals outlet openings 2, one for each sparkplug. Each of such openings has a nipple 3 integralwith the manifold and 10 surrounding the opening. Mounted in the nipple 3 is a contact support 4 of suitable insulation having a central socket like opening 5 in the bottom of which is the metal terminal plate 6 for the manifold conductor 1 which extends through 18 the end of the support 4 and the contact plate 6 and has its end riveted or peened over tightly against the plate 6, the plate 6 and peened over and of the conductor constituting the terminal. The parts are so joined and fitted at the nipple go that a fluid tight barrier is formed between the conduit for the spark plug lead and the interior of the manifold. The conductor I is connected through the manifold and suitable leads, with the magneto as is well understood. Within the manifold the conductor 1 has a suitable insulating covering 8.

The shielded spark plug lead comprises the metal tube 8 constituting the radio shielding con-' duit for the conductor I 0 from the manifold to 30 the spark plug, such conductor being bare adjacent its ends but otherwise having an insulating covering Ii. At the manifold end of the lead the bare end .30 of the conductor has the metal washer 3i threaded upon it, the washer bearing against the end of the insulation H and secured in position by bending over the end of the conductor and soldering or not as may be desired. soldered to the washer 3| isa spiral metal spring 32 adapted to press against and have flrm elec- 40 trical contact with the terminal of the conductor 7 when the conductor I0 is in operative position in the lead.

a One end of the tube 9 is permanently and securely joined with the nipple 3 by abutting its 5 end against the nipple, placing a metal band it" about'the nipple and tube to bridge the joint and securely, tightly and fixedly welding or soldering the whole together. I

The other end of the tube 9 has a flange i3 59 engaged by a flange ll of a nut i5 screw-threaded upon the end of the elbow l6, such nut serving to draw the ends of the tube 9 and "elbow IE tightly and firmly together, a gasket being interposedbetween the tube and elbow if' desired,

' to insure fluid tightness, This "elbow commonly so called, is the curved portion of the metal shielding conduit connecting with the spark plug.

The spark plug end of the elbow has screwed upon it the metal member I I having the flange l8 engaged by the flange IS on the threaded nut 20 adapted to be screwed onto the spark plug shield to secure the elbow tightly and securely thereto as is well understood.

Screwed into the member I! is a tubular mounting 2| of insulation into the bore 22 of which extends the insulation covered conductor l0, and also in the bore 22 is the metal contact washer 24 threaded on the conductor and bearing against the end of the insulation II. The washer is held in position by bending over the end of the conductor on the outside and soldering or not as desired. Also in the bore 22 is the disk 25 bearing at one side against the end of the conductor l and to the. other side is soldered one end of a metal spring 26 adapted to hear at its other end against the central electrode of the spark plug.

The spring thus acts to connect the conductor Ill with the electrode of the sparkplug and is of such dimensions and resilience as to tightly press the conductor Ill, disk 25 and spark plug contact together so that there will be good and firm electrical connection between them. The other end (that adjacent the manifold) of the conductor in bears through the spring 32 against the contact plate 6 or the riveted end of the conductor i so that firm electrical connection is established from the conductor 7 to the spark plug electrode.

If now it be desired to remove the conductor because of injury, or for any reason, the elbow" may be separated from the tube 9 by unscrewing the nut l when the conductor being unsecured to the contacts at its ends may be withdrawn from the tube and elbow by simply pullingit out, or the elbow may be separated from the spark plug shield by unscrewing the nut 29 and then the conductor can be pulled out through the spark plug end of the elbow.

A new conductor may be inserted, where the elbow and tube 9 are separated by pushing one end of the conductor endwise into the tube until the spring at its manifold end is compressed and bears firmly against the terminal of the manifold conductor and pushing the other end of the in-.

serted conductor into the elbow and securing the elbow in position when the spring 26 will be compressed and securely connect the conductor in with the spark plug electrode. Preferably the conductor is solid rather than stranded but any type may be used having the desired characteristics as indicated.

When the parts are disassembled at the nut 26 instead of at the nut l5, the new conductor may be'pushed endwise inwardly from the spark plug end of the elbow, through the elbow and conduit tube 9 so that its inserted end bears against the terminal contact of themaniiold conductor and the parts then assembled as described.

While the invention has been illustrated in what-is considered its best application it may have other embodiments without departing irom its spirit and is not therefore limited to the structures shown in the drawing.

What we claim is:

1. In an engine ignition system, the combination with a'manifold having an opening, of a radio shielding conduit permanently secured at one end to said manifold adjacent said opening, means at the other end of said conduit for connecting it with the spark plug radio shield and providing a radio shielded passage from said conduit to said spark plug shield, a conductor in said manifold, a terminal for said conductor mounted adjacent said opening and a conductor in said conduit insulated from the metal thereof and adapted at one end to be connected with the electrode of a spark plug and at the other end bearing against said terminal but being unsecured thereto against a Dull tending to withdraw said conductor from said conduit.

2. In an engine ignition syste the combination with a manifold having an opening, of a radio shielded conduit permanently secured to said manifold adjacent said opening, a conductor in said manifold, terminals for said conductor adjacent said opening and a conductor in said conduit bearing against said terminal in conducting engagement therewith. and adapted to be connected and disconnected therefrom by the inser-, tion in and withdrawal of the last mentioned conductor from said conduit.

3. In an engine ignition system, the combination with a manifold having an opening, of a radio shielding conduit permanently secured at one end. to said manifold adjacent said opening,

a radio shielding elbow at the other end of said conduit, means for connecting said elbow with the spark plug radio shield, a conductor in said manifold, a terminal for said conductor mounted adjacent said opening and a conductor in said conduit insulated from the metal thereof and adapted at one end to be connected with the electrode of a spark plug and at the other end bear-. ing against said terminal, but being unsecured thereto against a pull tending to withdraw said conductor from said conduit.

4. In an engine ignition system, the combination with a manifold having an opening, of a radio shielding conduit permanently secured at one endto said manifold adjacent said opening, means at the other end of said conduit for connecting it with the spark plug radio shield and providing a radio shielded passage from said conduit to said spark plug shield, a conductor in said manifold, a terminal for said conductor mounted adjacent said opening and an insulated covered conductor in said conduit and adapted at one end to be connected with the electrode of a spark plug and at the other end bearing against said terminal but being unsecured thereto against a pull tending to withdraw said conductor from said conduit.

5. In an engine ignition system, the combination with a manifold having an opening, of a radio shielding conduit permanently secured at one end to said manifold adjacent said opening,

' electrode of a spark plug and at the other end bearing against said terminal but being unsecured thereto against a pull tending to withdraw said conductor from said conduit, there being at the spark plug end of the conductor in the conduit a spring-pressed terminal against which the last mentioned conductor detachably bears.

6. In an engine ignition system, the combination with a manifold having an opening, of a conductor therein, a radio shielding conduit permanently secured to said manifold adjacent said opening, a terminal for the manifold conductor adjacent said opening and a conductor in said conduit separate from but electrically connected with said terminal.

7. In an engine ignition system, the combination with a manifold having an opening, of a conductor therein, a radio'shielding conduit permanently secured to said manifold adjacent said opening, a terminal for the manifold conductor adjacent said opening and a conductor in said conduit detachably connected with said terminal and means forming a fluid-tight barrier between said conduit and said manifold.

8. In an engine ignition system, the combination with a manifold having an opening, of a conductor therein, a radio shielding conduit permanently secured to said manifold adiacent.

said opening, a terminal for the manifold conductor adjacent said. opening and a conductor in said conduit detachably connected with said terminal and means forming a fluid-tight barrier between said conduit and said manifold; the said terminal being mounted in said barrier.

9. In an engine ignition system, the combination with a manifold having an opening, of a radio shielding conduit tly secured to said manifold adjacent said opening. a conductor in said manifold, terminals for said conductor adjacent said opening and a conductor in said conduit bearing against said terminal in conducting engagement therewith and adapted to be connected and disconnected therefrom by the insertion in and withdrawal of the last mentioned conductor from said conduit, the last mentioned. conductor having at its end aspring secured to it and compressed against said terminal.

10. In an engine ignition system, the combination with a manifold having an opening, of a radio shielding conduit permanently secured to said manifold adjacent said opening, a conductor in said manifold, terminals for said conductor adjacent said opening'and a conductor in said conduit bearing against said terminal in conducting engagement therewith and adapted to be connected andrdisconnected therefrom by the insertion in and withdrawal of the last mentioned conductor from said conduit, the last mentioned conductor having at its end a spring secured to it and compressed against said terminal and a spring at the spark plug end of the conductor adapted to be compressed against a spark plug electrode.

MILVIILE I". PETERS. R. HARRY STONE.

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