Adjustment tool for rotatable instrumentalities

An adjustment tool for a rotatable preset potentiometer used in television receivers, or the like, is formed of one-piece, molded plastic material and is insertable into the hollow rotatable hub of the potentiometer. The tool has a shaft which extends into and through the hub of the potentiometer. A resilient, deformable locking member which normally expands to a size greater than the hole in the hub, is carried on one end of the shaft. The locking member is compressible upon insertion into and removal from the hub, and is located to expand outside the hub when the tool is inserted into place. Drive slots are formed in the end of the hub. The tool has a pair of drive slot engaging members at its other end which limit the depth to which the tool can be inserted. These members engage the slots in the hub to permit the tool and the hub to be rotated together. An enlarged head is formed on the end of the shaft having the slot engaging members on it and is of a size to permit it to be grasped for manual rotation. The head also includes a screwdriver receiving slot in it, and has cammed surfaces sloping toward the slot to facilitate the location of a screwdriver blade into the slot, so that the adjustment of the potentiometer can be easily effected.