US1739118A

US1739118A - Spark gap and shield

Info

Publication number: US1739118A
Application number: US168143A
Authority: US
Inventors: Earl E Bidwell
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-02-14
Filing date: 1927-02-14
Publication date: 1929-12-10
Anticipated expiration: 1946-12-10

Description

Dec. 10, I929. E. E. BIDWELL SPARK GAP AND SHIELD Filed Feb. 14, 1927 INVENTOR. EARL E. BIDWELL Maw A TTORNE Y.

Patented Dec. 10, 1929 EAR-L E. BIDVELL, OF WICHITA, KANSAS SPAR-K GAP AND SHIELD AppIication filed February 14, 1527. Serial 230. 188,143.

This invention relates to engines and the primary object thereof is to provide a combined intensifier and moistureshedding hood to be associated with the spark plug so that theintensity of the spark at the point of ignition willbe enhanced and whereby the device will act as a shedding means to prevent short circuiting' -between the positive electrode and the shell due to the accumula- 'tion of moisture along the insulating porcelain. In those plugs to the electrodes of which the saidwire'sare directly attached, there is always danger of short circuiting because rain or other moisture may flow along 1.5 the insulation on to the plug shell to thereby form a short path for the current with practically no resistance. My invention eliminates the possibility of'this, due to the fact that no water or other moisture can "pass di- 2o rectly from the electrode to the shell, The hood efficiently sheds the water away from contact with the electrode and since the gap between the hood and the shell is greater than thegap between the hood and the elec- 2 trode, the spark will always jump across the intensifier gap'which is the space between the edge of an opening in the hood and the electrode. I have provided means for maintaining a uniform distance between the hood or intensifier elementand the electrode so that the proper intensifying gap can be maintained. V

Other objects and advantages of the invention will be apparent by reference to the following description in connection with the accompanying drawings in which:

' Figfl is an elevation of a spark plug showing the-shield in position, parts removed for convenience of illustration.

' Fig. 2 is a top end view of Fig. 1.

Fig. 3 is a sectional View through the shield and insulations connected therewith.

The device is illustrated as comprising a metallic hood 1 in the form of an inverted cup having a central aperture 2 through which the upper end of the positive electrode 3 extends. The aperture has a greater crosssectional area than that of the electrode so that a spark gap is provided between the edgeiof the aperture and the electrode. Un-

der the top B of the hood is an insulating disc a of porous lnsulating material. The diameter of the disc is equal to the inner diameter of the cup-shaped hood and the orifice through which the electrode extends is of substantially the same diameter as that of the electrode so that the hood is rigidly held against the jam nut of the spark plug to thereby maintain a uniform annular spacing between the electrode and the edge of the opening 2 so that the spark gap between the edge of the opening 2 and the electrode is equally spaced entirely around the electrode. On the outer face (that is, on top of the hood) is an insulating disc 5 overlapping the edge of the opening 2 and snugly fitting about the electrode so that when the nut 6 is screwed on to the electrode 3, the hood will be protected against liability of moisture entering the spark gap to form a short circuit. On the hood is a binding post 7 to which may be fastened the said wire 8 in the usual man ner. C is the insulator or porcelain for the electrode 3 and D is a spark plug shell. It will be observed that the inner diameter of the hood is considerably greater than the outer diameter of the porcelain and that there is a considerable space between the bottom edge of the hood and the nut A of the spark plug so that danger of the spark umping from the lower edge of the hood to the shell of the spark plug will be entirely eliminated. Since the wall of the hood is spaced a considerable distance from the porcelain C and since the disc 5 prevents moisture from passingthrough the opening 2, it will be apparent'that danger of rain or moisture filming along the porcelain and thereby forming a short circuit will be eliminated.

In some cases I may desire to dispense with the intensifier feature of my invention and still retain the advantages of the moisture shed or protector, in which event, the disc 4; may be removed from the interior of the cup and it together with the disc 5 may be held against the upper face B of the cup by the nut 6, then the current will pass directly from conductor 8, through the binding post '7 to hood 1, through the jam nut of the spark plug to electrode 3 without having an intensifying effect. The device can be read ily applied to any conventional spark plug, so I have shown it applied to a common type of plug now generally used.

What I claim and desire to secure by Letters-Patent is: I

1. In a spark gap and shield, in combination with a spark plug, a hood having an aperture in the top thereof to receive the electrode of the plug, said aperture being greater in diameter than the electrode, an insulation member positioned in the top of the hood, an insulation member to engage on the outside of the top of the hood, apertures through said insulations in registry with each other and concentrically positioned to the aperture in the hood to receive the electrode snugly, a binding post attached to the exterior and near the top of the hood, means for connecting the current wire to the post. 7

2. In a spark gap and shield, in combination with a spark plug for an internal combustion engine, a hood having an aperture concentrically positioned in the top thereof to engage on the electrode of the plug with the contact to "form a gap peripherally around the electrode, an insulation member to fit snugly in the top of the hood, an aperture centrally positioned in said insulation to snugly engage on the electrode as centering means therefor in the aperture of the hood, an apertured insulation for the exterior of the hood to engage with the electrode, and a nut threadedly engaging on the electrode as binding means therefor to the hood, means for connecting the electric current to the hood in close proximity to the top thereof, all as, and for the purpose described.

3. In combination with a spark plug having an electrode extending therefrom, of a combined spark gap and moisture shedding hood associated therewith, the hood having an opening of greater diameter than the electrode,the edge of the opening surrounding the electrode, an insulating disc within the hood, the periphery of which bears against the outer wall of the hood and through the center of which the electrode extends so that the edge of the opening of the hood will be uniformly spaced about the electrode and a binding post on the hood.

4. Incombination with a spark plug having an electrode extending therefrom, of a combined spark gap and moisture shedding hood associated therewith, the hood having an opening of greater diameter than the electrode, the edge of the opening surrounding the electrode, an insulating disc within the hood, the periphery of which bears against the outer wall of the hood and through the center of which the electrode extends so that the edge of the opening of the hood will be uniformly spaced about the electrode, a washer on the outer face of the hood overlapping the edge of the opening and snugly fitting the electrode, a nut on the electrode bearing against the second mentioned washer for binding the hood to the spark plug and a binding post on the hood.

5. In combination with a spark plug having an electrode extending therefrom, of a cup-shaped hood associated therewith, said hood having a central opening in its top of greater diameter than that of the electrode so that the edge of the opening is spaced from the electrode, a washer within the hood, the edge of which bears against the inner face of the hood to centralize it with respect to the electrode so that the edge of the opening will be spaced a uniform distance from the electrode, a washer on the electrode bearing against the outer face of the hood overlapping the edge of the opening, a nut on the electrode binding the washer against the hood and a binding post on the hood.

6. In a spark gap and shield, in combination with a spark plug, a metal hood having an aperture concentrically positioned in the closed end thereof, the aperture being larger in diameter than the electrode of the plug, whereby a spark gap is formed, an insulation fitting snugly on the inside of the closed end of the hood and having an aperture centrally positioned, the aperture to fit snugly on the electrode as closing means for the gap, and a nut threadedly engaging on the electrode as securing means for the hood to the outer end of the plug, a binding post integrally connected near the closed end of the hood.

7. In a spark gap and shield, in combination with a spark plug having an electrode axially extending theret-hrough, 'a metal hood having an aperture concentrically positioned in the closed end of the hood, the aperture being larger in diameter than the electrode of the plug, the inner end of the hood being spaced longitudinally from the the metal body of the plug, a binding post integrally connected to the hood in close proximity to the closed end, an insulation fitting snugly on the inside of the closed end of the hood and having an aperture centrally positioned and snugly fitting on the electrode as means to concentrically position the hood to the outer end of the plug, an insulation positioned on the outside, of the closed hood as concealing means for the aperture in the metal hood, and means to bind said insulations firmly together and simultaneously the hood to the spark plug, all as and for the purpose described.

8. A current-intensifying device compris ing a cup-shaped member of current-conducting mater1a=l and containing an aperture, a disk of current-lnsula'ting material snugly fitting in said i'nember and containing an aperture-in registration with the aperture 1n said member, said'apertures being provided to receive the upper end of the central electrode of a spark plug, the aperture in said member being of greater diameter than the aperture in said disk.

9. A current-intensifying device comprising a cup-shaped member of current-conducting material for connection with one terminal of an electric ignition circuit and the mounting thereof on the central electrode of a spark plug, and means engaging said electrode for securing said member on said electrode in spaced relation to the latter and insulating said member from said electrode.

10. In combination with a spark plug having an electrode projecting outwardly therefrom, a spark-gap device comprising an inverted cup-shaped member of currentconducting material for connection with one of the current-conducting wires and containing an opening therethrough of greater diameter than the diameter of said electrode and through which said electrode extends but out of contact with the wall of said opening, an insulating disk within said member and containing an opening concentric with the opening in said member but of smaller diameter than the latter and through which said electrode extends.

11. In combination with a spark plug having an electrode projecting outwardly therefrom, a spark-gap device comprising an inverted cup-shaped member of currentconducting material for connection with one of the current-conducting wires and containing an opening therethrough of greater diameter than the diameter of said electrode and through which said electrode extends but out of contact with the wall of said opening, and an insulating disk Within, and closely fitting, said member and containing an opening concentric with the opening in said member but of smaller diameter than the latter and through Which said electrode extends.

In testimony whereof I aflix my signature.

EARL E. BI'DWELL.