Locking type gasket for spark plugs having fully threaded shanks and tool therefor

In a combination spark plug and captive gasket therefore, in which said spark plug includes a plug body having a threaded shank extending outwardly therefrom, said threaded shank having threads thereon extending substantially the entire lenght of said shank, said gasket including a plurality of mutually compressible sealing flanges and a locking flange extending inwardly of said sealing flanges, said threaded shank having a given pitch and defining a continuous spiral recess between adjacent convolusions of said thread, the improvement comprising:

• said locking flange including a plurality of locking tabs, each tab including a main body portion lying inwardly of said sealing flanges, and generally longitudinally oriented with respect to the principal axis of said threaded shank, and a transversely extending portion interconnecting said longitudinally extending main body portion to one of said sealing flanges;
• said tabs having an effective length along said longitudinal axis substantially equal to the combined thickness of said sealing flanges in compressed condition, and being disposed within the area encompassed by said plurality of sealing flanges, whereby said longitudinally extending portions and sealing flanges define an arcuately-shaped interstice for the insertion of a staking tool therein;
• said locking tabs, in installed condition overlying portions of said thread, and being deformed to a degree wherein the radially inward surfaces thereof at least partially conform to the configuration of said thread.