Patent Publication Number: US-6210183-B1

Title: Spark plug and spark plug boot combination

Description:
This application is based on a Provisional Patent Application filed on Mar. 17, 1999, Ser. No. 60/124,837, having a title of “SPARK PLUG AND SPARK PLUG BOOT COMBINATION” by the subject inventor. 
    
    
     BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     This invention relates to spark plugs and spark plug boots and more particularly, but not by way of limitation, to an improved spark plug and spark plug boot combination for improved engine performance and ease in installation and removal of the plug and removal of the boot from the plug. 
     (b) Discussion of Prior Art 
     Today&#39;s vehicles have larger and larger engines with various engine accessories mounted on top and on the sides of the engines. This situation leaves little room for installing spark plugs in the engine block along with attaching spark plug boots with spark plug wires to the end of the sparks spark plugs. One vehicle manufacture provide “no” room for changing out spark plugs and the engine literally has to be removed to the engine mounts in order to change spark plugs. 
     There is a wide variety of spark plugs on today&#39;s market for different models and manufactures of vehicle engines. Also, there are different designs of spark plug boots and spark wire terminals for connecting spark plug wires to the spark plugs. None of the prior art spark plug manufactures have addressed a problem of a spark plug boot, over a period of time, sticking to the sides of a spark plug making it difficult to remove the boot from the plug. Further, spark plug manufactures have not addressed a problem of threading a spark plug boot on a spark plug when there is little room for installation next to the engine. 
     The subject invention addresses the problem of limited working space when working on a vehicle engine and installing spark plug boots on spark plugs and removing spark plug boots from the plugs. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is a primary object of the subject invention to provide an improved spark plug and spark plug boot combination used with an internal combustion engine for overall improved engine performance. 
     Another object of the invention is the new spark plug and spark plug boot combination provides for ease in snugly securing the spark plug boot to the spark plug when space is limited next to the engine. 
     Still another object of the plug and boot combination is to provide for ease in removing the spark plug boot from the spark plug which heretofore was difficult to remove because of the boot sticking to the sides of the plug. 
     A further object of the invention is the plug and boot combination reduces “flash over” and static electricity with improved engine performance and fuel economy. 
     Yet another object of the invention is the spark plug boot includes a plug wire connector with plug wire swivel which allows a spark plug wire to swivel on the plug wire connector for ease in attaching the boot to the spark plug when working in tight conditions. The plug wire connector also includes quick release snap-in connector ribs for releasing the plug wire connector from an end of the spark plug boot. 
     The spark plug and spark plug boot combination includes a spark plug having external threads formed in a ceramic housing of the plug. The boot includes internal threads formed inside a boot housing for releasable engagement of the external threads on the ceramic body of the spark plug. The boot also includes a spark plug wire connector having “snap-in” connector ribs. The connector ribs are used for releasable receipt in one end of the boot housing. The connector has a plug wire swivel in a connector housing which allows a spark plug wire to be pivoted on the spark plug wire connector when the boot is attached to the spark plug or removed from the spark plug. Along the exterior sides of the boot are longitudinal splines which are used for gripping the boot during installation and removal from the spark plug. 
     These and other objects of the present invention will become apparent to those familiar with spark plugs, spark plug boots and spark plug wire terminals used with internal combustion engines when reviewing the following detailed description, showing novel construction, combination, and elements as herein described, and more particularly defined by the claims, it being understood that changes in the embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate complete preferred embodiments of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which: 
     FIG. 1 is a perspective view of the new spark plug with external threads formed in a ceramic housing of the spark plug. A spark plug boot is positioned above the spark plug with a portion of the spark plug boot cut away to expose internal boot threads for engaging the external threads in the ceramic housing. Disposed above the spark plug boot is a spark plug wire connector positioned for connection in an upper end of the spark plug boot. 
     FIG. 2 is a front cut away view of the spark plug boot attached to the sides of the ceramic housing of the spark plug. Also, a portion of the spark plug wire connector is shown cut away and received in the upper end of the spark plug boot. A spark plug wire terminal is shown attached to a spark plug cap of the spark plug for making an electrical connection to the spark plug. 
     FIG. 3 is a perspective view of the subject invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, a perspective view of a new spark plug having general reference numeral  10  is illustrated with a spark plug boot having a general reference numeral  12  position above the spark plug  10 . Also illustrated in this drawing is a spark plug wire connector  14  disposed above the spark plug boot  12  and positioned for connection thereto. 
     The new spark plug  10  is characterized by having four-lead threads  16  in a ceramic housing  18  of the spark plug  10 . The spark plug  10  also includes a metal housing  20  with a twelve-point nut  22  therearound for threading engine block threads  24  into an engine block. The engine block is not shown in the drawings. Further, the spark plug  10  includes an electrode  26 , electrode ground  28  and spark plug cap  30 . 
     The new spark plug boot  12  is shown positioned above the spark plug  10  and ready for threading onto the ceramic body  18  as indicated by arrow  32 . A portion of a spark plug boot housing  34  with housing opening  35  has been cut away to expose four-lead internal boot threads  36  around the sides of the opening  35 . Also around an upper portion of the sides of the opening  35  are a pair of internal grooves  37 . The internal boot threads  36  are used for engaging the four-lead external threads  16  on the ceramic housing  18  and snugly securing the spark plug boot  12  on the spark plug  10 . It should be mentioned that heretofore, a prior art spark plug boot was received around the ceramic body of a spark plug in a press fit. With time, the inside of the boot would adhere to the spark plug and when changing the spark plug, the boot would be difficult to remove. 
     When using the subject invention, the spark plug boot  12  is threaded onto the spark plug  10  for ease in a secure fit when installing the boot. Also, the threaded spark plug boot  12  provides for ease in removing the boot  12  from the spark plug  10 . Further, the threading of the spark plug boot  12  onto the spark plug  10  reduces spark plug “flashover” thereby improving the plug performance. The boot  12  also includes a plurality of longitudinal splines  38  along the length of the boot housing  34 . The splines  38  are used for gripping the sides of the boot  12  and rotating the boot when removing it from the spark plug  10 . 
     Disposed above the spark plug boot  12  is the spark plug wire connector  14 . The connector  14  is positioned for connection in an upper end  40  of the spark plug boot  12  as indicated by arrow  42 . The connector  14  includes a connector housing  44  with a plug wire swivel  46  pivotally mounted thereon as indicated by arrows  47 . The plug wire swivel  46  is attached to a lower end  48  of a spark plug wire  50 . The lower end  48  of the spark plug wire  50  is attached to a plug wire terminal  52  which is received around a top portion of the spark plug cap  30 . The plug wire terminal  52  is received insides a lower portion  54  of the connector housing  44 . The plug wire terminal  52  is shown in FIG.  2 . 
     The lower portion  54  of the connector housing  44  includes a pair of external ribs  56  therearound which are used for a quick release connection inside the upper end  40  of the boot housing  34 . The external ribs  56  of the connector housing  44  are secured in a press fit in the internal grooves  37  of the boot housing  34 . 
     In FIG. 2, a front cut-away view of the spark plug boot  12  is illustrated and attached to the sides of the ceramic housing  18  of the spark plug  10 . Also, a portion of the spark plug wire connector  14  is shown cut-away and received in the upper end  40  of the spark plug boot  12 . In this view, the spark plug wire terminal  52  is shown attached to the spark plug cap  30  of the spark plug  10  for making an electrical connection from the spark plug wire  50  to the spark plug  10 . The terminal  52  includes an internal threaded screw  58  for securing the lower end  48  of the spark plug wire  50  thereto. The plug wire swivel  46  is designed to rotate the spark plug wire  50  on the terminal  52  and allow the spark plug wire  50  to be rotated upward to 180 degrees on the connector housing  44  for ease in working in tight conditions when installing or removing the spark plug boot  12 . 
     Also shown in FIG. 2, is the metal housing  20  of the spark plug  10  cut-away to expose the entire length of the ceramic housing  18 . A lower portion  60  of the ceramic housing  18  includes external buttress threads  62  for threaded attachment to internal threads  64  around an opening  66  in the metal housing  20 . When the external buttress threads  62  are secured to the internal threads  64  in the metal housing, a ceramic epoxy is applied under pressure through a fill port  68  in the side of the metal housing  20 . In this manner, the metal housing  20  is securely attached to the ceramic housing  18  and spark plug “flash over” and radio static is reduced. 
     In FIG. 3, a perspective view of the spark plug  10 , the spark plug boot  12  and the spark plug wire connector  14  are illustrated. 
     While the invention has been shown, described and illustrated in detail with reference to the preferred embodiments and modifications thereof, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention as claimed, except as precluded by the prior art.