Adjustable clamp

In a bar clamp having a bar and a pair of opposed work-engaging jaws mounted thereon with at least one of the jaws mounted on a jaw carrier slidable on the bar, at least one jaw carrier brake key apertured for both sliding and tilting movement on the bar and mounted on the bar in braking relationship with said jaw carrier;

• and spring means biasing said jaw carrier brake key into a tilted braking position on the bar in which it grips the bar and brakes the jaw carrier against sliding movement in one direction on the bar while permitting said jaw carrier to slide on the bar in the opposite direction, said jaw carrier brake key being manually tiltable so as to temporarily release its grip on the bar,
• the improvement which comprises, a one-way jaw carrier drive mechanism comprising, a jaw carrier drive lever having an apertured jaw carrier drive portion slidably and tiltably mounted on the bar independently of said jaw carrier and an operating handle, an apertured carrier drive lever brake key tiltably disposed on the bar in braking relationship with said apertured jaw carrier drive portion, a compression spring surrounding the bar and slidable thereon with one end engageable with said carrier drive lever brake key, and a compression spring retainer having a portion which engages the end of said compression spring opposite said first-mentioned one end thereof and an attaching portion which removably attaches said retainer to said jaw carrier and retains said compression spring in a compressed condition against said carrier drive lever brake key and thereby biases said apertured jaw carrier drive portion of said jaw carrier drive lever against said jaw carrier, said apertured jaw carrier drive portion being pivotable on the bar by means of its operating handle between a non-operating position into which it is biased by said compression spring and pivoted driving positions in which it drives said jaw carrier to shift on the bar, the compression spring biasing said carrier drive lever brake key into a tilted gripping relationship with the bar in which it brakes said jaw carrier drive lever from shifting o the bar when said jaw carrier drive lever is in its pivoted driving positions, said bar clamp being operable as a bar clamp when said jaw carrier drive lever, said apertured carrier drive lever brake key, said compression spring and said compression spring retainers are removed therefrom.