US 3293352 A
Description (OCR text may contain errors)
Dec. zo, 1966 R. G. LIVINGSTON SPARK PLUG ATTACHMEN1 FOR GROUNDING SHEATHED WIRES Filed April 24, 1964 IN VENT 0R. 6. UWA/6570# Stfa Pgs @j ,4 fram/.5y
United States Patent O 3,293,352 SPARK PLUG ATTACHMENT FOR GROUNDING SHEATHED WIRES Russell G. Livingston, Los Angeles, Calif., assignorto Hallett Manufacturing Company, Los Angeles, Calif., a corporation of California Filed Apr. 24, 1964, Ser. No. 362,403 Claims. (Cl. 174-35) The present invention relates to a wire support and a sheath connector for sheathed ignition wires and more particularly to a device adapted for effecting a ground connection between a metallic sheath of a spark plug wire so as to assist in the elimination of the transmission of signals causing interference or static in a radio in a motor vehicle.
Interference in two-way radios which are employed in automobiles and the like and which transmit on the low frequency ranges is a problem particularly when the receiver is some distance from the transmitter, so that the broadcast signal is weak. Ordinarily, under such cir` cumstances it is necessary to shut off the engine to eliminate engine ignition noise.
It is known that predominantly the engine ignition signals which cause the above noted interference emanate from the ignition wires. Accordingly, the present invention contemplates means for simply and effectively connecting and grounding a metallic sheath or shield which may be disposed upon the ignition wire which extends between the engine ignition distributor and the spark plugs.
The present invention contemplates a device mountable upon a spark plug so as to make a ground connection with the spark plug base, the device including means for connection to an end of the metallic sheath.
Obviously, the spark plug wire shielding may be grounded and anchored at its end remote from the spark plug by means of the support and grounding device as more particularly described and claimed in my co-pending application filed concurrently herewith, Serial No. 362,404 entitled Sheathed Ignition Wire Support and Sheath Connector.
In a specific sense, it is an object of the present invention to provide means for clampingly and electroconductively engaging the hexagonal wrenching portion of a spark plug, said means carrying a `support arm projecting therefrom, the arm being bendable so as to assume any desired inclination or disposition relative to the clamping means as may be desired or necessary in connection with any given spark plug location as related to the location of the distributor from which the spark plug wire extends. This support arm has means at its outer extremity for enabling the anchoring of the end of a metallic shielding sheath extending along the spark plug wire.
Other objects and advantages of the invention will be hereinafter described or will become apparent to those skilled in the art, and the novel features of the invention will be defined in the appended claims.
In the accompanying drawing:
FIG. 1 is a view in perspective illustrating a spark plug attachment having means for electroconductive anchorage of a metallic sheath, and made in accordance with the present invention.
FIG. 2 is a longitudinal sectional view illustrating the spark plug attachment of FIG. l and showing in broken lines various positions which may be assumed by the support arm of the attachment and also showing in broken lines a spark plug embraced within the attachment;
FIG. 3 is an enlarged fragmentary sectional view as taken on the line 3-3 of FIG. 2;
FIG. 4 is a bottom plan of the assemblage of FIG. 2; and
FIG. 5 is a view generally corresponding to FIG. 2 but illustrating a modified form of the spark plug attachment.
Like reference characters in the several views of the drawings and in the following description designate corresponding parts.
In the illustrative embodiment of FIG. 1, the spark plug attachment of the present invention is seen to comprise an elongated metallic member 1 having at its lower extremity oppositely extended arcuate sections 2 and 3 terminating in mutually confronted relation and defining therebetween a slot 4, and having at its upper extremity means for anchoring and electroconductively connecting a metallic spark plug wire sheath to the member 1 and thence to a spark plug through the arcuate portions '2 and 3.
As seen in FIG. 2, the arcuate portions 2 and 3 constitute means for gripping the hexagonal body portion 6 of a spark plug S. The attachment is preferably comprised of sheet metal having resilience so that the arcuate portions 2 and 3 will normally be resiliently biased into tight engagement with the corners of the hexagonal plug portion 6.
The member 1 is of such length as to project upwardly beyond the upper extremity or cap 7 of the spark plug S and as shown in broken lines in FIG. 2 is adapted to be bent to any selected disposition relative to the clamping means and relative to the spark plug S so as to support the spark plug wire SW in a desired relation to the distributor from which the spark plug wire extends.
The sheath anchoring means previously referred t0 and as best seen in FIG. 3 in the embodiment thus far described, comprises a metallic grommet 8 carried by an end flange 9 at the upper extremity of the member 1. The grommet and means for anchoring the end of the metallic sheath 10 to the grommet are the subject matter of the above noted co-pending patent application, but 1n general it will be noted that the grommet is provided with an outer peripheral groove 11 into which an end of the sheath 10 which has been turned back about the outside of the grommet is clamped by a split snap ring 12, the clamped end of the sheath and the grommet being encased within a rubber boot 13 which closely fits about the grommet and which has a section 14 which closely fits upon the spark plug wire SW.
Referring to FIG. 5, it will be observed that this modified version of the spark plug attachment like that first described has an elongated member 1 and the clamping means comprising arcuate sections 2 and 3 forming the slot 4 whereby the spark plug S is clampingly engaged as described above. However, at its upper extremity the member 1 of FIG. 5 is provided with means which anchor the end of the spark plug wire sheath 10, but otherwise the attachment affords no support for the spark plug wire SW. In this embodiment the sheath 10 is in a known manner provided with a pigtail 10a by passing the spark plug wire SW through an opening formed by spreading apart the side wall of the mesh to form a spark plug wire opening. The pigtail 10a is secured electroconductively to the member 1 by fastener means 12a engageable with the end of the pigtail and with an out-turned end flange 9a on the member 1.
In each of the embodiments described, it is apparent that the member 1 is sufficiently laterally displaced from the spark plug S as to preclude arcing across the gap between the connector cap 7 of the spark plug and the ground attachment, but in any event, the spark plug S is preferably covered by a typical rubber boot 15 in each embodiment.
Inasmuch as the metallic base of the spark plug is threadedly engaged in the cylinder head of an engine and inasmuch as the clamping means 2 and 3 of the attachment are in electroconductive engagement with the hexagonal portion 6 of the spark plug While the member 1 is electroconductively connected to the sheath 10, it will be apparent that the metallic sheath 10 will be eifectively grounded adjacent the spark plug, while at its other end the sheath 10 may be grounded by connection to the sheathed ignition wire support and sheath connector of the above referred to co-pending patent application. As a result,the grounded shielding sheath effectively shields the spark plug wire against the transmission therefrom of signals which would otherwise result in objectionable ignition noise in a radio forming part of the equipment of a vehicle in which the spark plug is employed.
While 'specic structural detailshave been shown and described, it should be understood that changes and alterations may be resorted to without departing from the spirit of the invention as defined in the appended claims.
1. Shield means for grounding the metallic sheath of a spark plug wire comprising in combination: a spark plug for an internal combustion engine and having a metal base; a wire connected to said plug for supplying electrical energy thereto; an electrically conductive sheath on said wire; an elongate metal shield member having a length greater than that of said plug; said shield mernl plug; and metal clamp means on said other end of said arm engaging and making electrical connection with said sheath.
2. The shield means as set forth in claim 1, wherein said clamp means on said other end of said arm includes a grommet surrounding and supporting said wire.
3. The shield means as set forth in claim 1, wherein said arcuate clamp includes a pair of resilient arcuate members that terminate in mutually confronting portions with a slot therebetween and engageable With said metal base of said plug.
4. The shield means as set forth in claim 1, wherein said arm constitutes means bendable at any point between its ends to dispose said clamping means and said other end in different positions With respect to said plug best for effecting an electrical connection of said clamp means to said sheath.
5. The shield means as set forth in claim 1, wherein said wire extends through a side of said sheath, said sheath having a pigtail projecting from said wire and connected to said clamp means.
References Cited by the Examiner UNITED STATES PATENTS 2,730,562 l/l956 Marden 174-35 3,128,139 4/1964 Estes 174-35 X FOREIGN PATENTS 324,402 l/ 1930 Great Britain.
LEWIS H. MYERS, Primary Examiner.
D. L. CLAY, Assistant Examiner.