Three piece knob assembly including a cap

Claim 1

A knob assembly comprising a knob having a top end and a bottom end, said knob defining an aperture including a first bore in said bottom end and including a second bore in said top end, said knob defining a seat around the upper end of said first bore and a shoulder around the lower end of said second bore; said knob having an intermediate interior surface with a non-circular configuration defining an intermediate portion of said aperture connecting said first and second bores, said knob intermediate interior surface terminating at one end along the inner periphery of said shoulder and at the other end along the outer periphery of said seat; nut means for mounting the knob assembly and having a configuration corresponding to, and disposed in, said intermediate aperture portion of said knob against said seat to prevent relative rotation between said knob and said nut means; a cap having a cylindrical top end received in said second bore, said cap having a cylindrical bottom end with a bottom surface extending into said intermediate aperture portion for being positioned above said nut means in said intermediate aperture portion, said cap cylindrical bottom end having an outside diameter not exceeding the smallest cross-sectional dimension of said intermediate aperture portion, said cap top end defining a flange having an outside diameter about equal to that of said second bore, said cap further including a plurality of walls extending radially outwardly and depending from said cap flange, each said wall defining a bearing surface, said cap being disposed in said knob with said bottom surface of said cap bottom end engaging said nut means in said intermediate aperture portion and with said cap flange positioned in said second bore with said depending wall bearing surfaces supported on said shoulder; and means for securing said cap to said knob whereby said cap positively holds said nut means in position within said knob.