US2666423A

US2666423A - Radiation shield for spark plugs

Info

Publication number: US2666423A
Application number: US210044A
Authority: US
Inventors: Jr Guy D Johnson
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-02-08
Filing date: 1951-02-08
Publication date: 1954-01-19
Anticipated expiration: 1971-01-19

Description

Jan. 19, 1954 a. o. JOHNSON, JR

RADIATION SHIELD FOR SPARK PLUGS Filed Feb. 8. 1951 INVENTOR V GUY 0. JCHNSON, JR. BY

flf/ar/Itj Patented Jan. 19, 1954 2,666,423 RADIATION SHIELD FOR, SPARK PLUGS Guy D. Johnson,

the United States of A the Secretary of the Ar Jr., Red Bank, N. J., assignor to merica as represented by Application February 8, 1951, Serial No. 210,044

1 Claim.

(Granted under Title 35, U. S. Code (1952),

' sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment of any royalty thereon.

This invention relates to radiation suppression shields for the high voltage sparking systems of internal combustion engines and particularly to shielding the spark plugs therefor.

The suppression of radiation is only one characteristic which such shields must possess. The present invention has to do not only with prevention of radiation but is particularly directed to providing such a shield having maximum mechanical ruggedness coupled with greatly facilitated means for installing upon and removing from all types of internal combustion engines.

The invention also provides for tightly sealing the shielding system against moisture, which not only prevents internal corrosion thereof but also maintains the electrical system at its top eniciency.

The shield is composed of a top section and abase section. The top section may have any suitable construction adapted to enclose the upper portion of the spark plug and has provision for the reception of the end of the high voltage sparking cable connected to the spark plug electrode. Desirably provision should also be made for connection of the spark plug shield to the shielding system for the remaining elements of the engine sparking system.

The base section of the shield is of special construction and is generally cup shaped. The bottom wall thereof desirably is made relatively thin and has an aperture therein for the reception of the threaded nipple on the spark plug. The side wall of the base section extends upward to embrace the hexagonal wrench receiving portion of the spark plug and is provided with means to rotatably couple the base section to the plug. The base section thus serves as a drive nut when installing the spark plug. Desirably also the base section is provided with screw threads for securing and sealing it to the top member of the shield.

It is an object of the invention to provide a spark plug shield offering effective radiation suppression together with superior structural char acteristics.

A still further object of the invention is to provide a spark plug shield having means for installing which is adapted to the design of conventional spark plugs especially with respect to their installation upon engines of conventional design.

Another object of the invention is to provide a spark plug shield having a base portion interengaging with and acting as the driving means for the spark plug when it is installed or removed.

A still further object of the invention is to provide a spark plug shield which can be installed and. serviced with conventional tools and standardized equipment.

Other objects and features of the invention will more fully appear from the following description taken in connection with the accompanying drawings and will be particularly pointed out in the claims.

To provide a better understanding of the invention, a particular embodiment thereof will be described herein and illustrated by the accompanying drawings in which:

Fig. 1 is the vertical cross sectional view of a preferred embodiment of the invention showing a spark plug in operative position within the shield;

Fig. 2 is a cross section on line 22 of Fig. 1;.

and

Fig. 3 is a cross section of line 3-3 of Fig. l.

A shield constructed under the principles of the invention is extremely compact and for that reason may be applied to engines having limited space areas for the reception of spark plugs. The shield is composed of two main sections, a relatively short base section I and a top section 2. The top section is secured to the base section in any desired manner such as by screw threaded means.

A convenient manner of tightly uniting the members I and 2 is to provide screw threads 3 upon the upper end of the base I. The screw threads receive a complementary threaded clamping member 4, having a flange 5 arranged to overlie an outwardly extending flange 6 upon the lower end of the member 2.

To establish a tight connection between the members a compressible electrically conducting gasket 1 may be interposed between the top of the member I and the flange 6.

The member 2 as shown is substantially of hollow cylindrical form having an internal diameter sufficient to receive the upper portion of the spark plug 8 and is provided with an internal insulating member 9 secured to the inner surface thereof. The member 2 is made of imperforate metal, as shown, to form a complete inclosure for the plug.

Any suitable means may be used to admit the spark plug cable ID to the interior of the shield.

A desirable means is shown in the drawing wherein an aperture is provided in the top wall of the member 2 and the insulating member 9 through which the cable extends to be connected to the electrode II of the spark plug. The member 2 is also provided with an integrally formed sleeve l2 through which the cable extends and which is provided with screw threads I3 for connection to a cable shielding system I4.

The base member I is constructed to impart to the whole shield a maximum of rigidity and durability coupled with a high degree of convenience for installation and servicing. With these ends in view the base is generally cup shaped having its side wall extending upward to embrace the lower portion of the spark plug and its hexagonal wrench receiving portion Ii. It will be noted that the member I closely embraces the spark plug and thus maybe made to present a small external diameter to enable it to be. readily received in. small areas such as the spark plug wells or other limited space provided therefor in conventional engines.

The upper portion of the base member i is made relatively heavy to withstand the stress imposed thereon by the. application of wrenches during installing :and removing operations. As shown herein the chamber within the base I has a cross sectional shape complementary to that of the hexagonal portion of the spark plug. The chamber may, however, have any convenient contour which will effectively rotatably couple the base member to the plug. The external face of the side wall of the base member is provided with wrench receiving areas I6 of any form or the external face of the side wall may have a conventional hexagonal conformation. The upper portion of the base member is made cylindrical and has screw threads formed thereon for engagement with the thread upon the clamping member 4-.

Thewrench re'ceiving'areas I6 are formed upon the relatively thick and rigid side wall of the base I thereby to withstand the excessive torsional stress resulting from the application of installing wrenches while the bottom wall thereof is made relatively thin to be clamped beneath theshoul der I1 of the plug.

The construction of the base member I may be modified by lengthening the side wall thereof and forming the wrench receiving areas thereon at a point a substantial distance above the base of the plug. This modified structure may be ading upon the cylinder block l9 of the engine and are bothrotated until the plug seats itself in opcrating position with the annular portion 20 of the "bottom" wall of the base member I clamped between the plug and the cylinder block of the engine. A conventional gasket 2| may be insertedto morenompletely seal the plug to the engine. The top portion 2 is then secured in place by tightening the locking member 4.

It will be particularly noted that standard wrenches may be used toinstall, remove and service the plug and its shield. Servicing of. the system is readily" accomplished by removing. the locking member '4 between the top section [and the base I whi'chpermits removal of the top section 2 thus exposing substantiallythewholeiplug and shield forinspecti'onand to perform. any required servicing operation.

I claim: 7

A cup shaped radiation'shield member'ior. a

spark plug having awrench receiving portion and a threads d attaching nipple "ending; in a shoulder, said member having a thin bottom wall withja hole through which the nipple maybe inserted with the shoulder against said wall; and a side wall having an innersurf'acein thei'orm: 'o'f'a Wrench to "be coupled to the wrench receiving portion oi the spark plug and a" corresponding outer surface in-the form of a wrench receiving means, and means on said side wall forattachihg a further shielding member to enclosetiie'spark plug.

GUY D. JOHNSON"; Hi1;

References; "Cited? in.- the. file of this patent UNITED STATES PATENTS Number Name Date 2,303,389 Rabezzana- -l. Dec; 11,. 1942 FOREIGN PATENTS Number Country Date 1,475 Great Britain c Feb. "24,1900 227,408 Great Britain d. Feb. 19. 1 925