Patent ID: 7976402

Claim:
An adjustable shaft, comprising: an upper shaft member having an elongated bore therein with a fixed upper bushing positioned within an upper end of the elongated bore therein; a lower shaft member having an elongated bore therein with a middle bushing fixed within an upper end of the elongated bore therein, the middle bushing having an elongated bore extending through the middle bushing; a helical inner rod having a lower bushing fixed to a lower end thereof, the bore of the middle bushing having a helical shape to accommodate the inner rod therethrough and to move the middle bushing relative to the upper bushing upon rotating the helical inner rod within the middle bushing; and a locking mechanism adapted to prevent the helical inner rod from rotating within the middle bushing, to thereby fix a total length of the shaft, wherein the locking mechanism comprises a threaded screw, which is positioned within an upper portion of the upper shaft member and prevents the helical inner rod from rotating relative to the upper bushing upon tightening thereof.