Device for fixing rods in selected relative position

Claim 1

Clamping means for securing coaxial, axially telescoping rods together, the clamping means comprising: a first part for attachment to the end of one of the rods adjacent the other rod; an annular bushing supported to the first part and extending around the other rod; the bushing being open along one circumferential side for defining an axial gap through the bushing; the bushing including first and second terminal portions on opposite sides of the gap in the bushing, such that drawing the terminal portions together reduces the gap and tightens the bushing around the other rod, and permitting the terminal portions to move apart loosens the bushing from around the other rod; a shaft extending from the second terminal portion past the first terminal portion; a clamp connected with the shaft for drawing the second terminal portion toward the first terminal portion; the first part blocking the first terminal portion from moving away from the second terminal portion as the second terminal portion is drawn toward the first terminal portion, whereby operation of the clamp draws the terminal portions together to clamp the bushing on the other rod; said clamp comprising a cam connected with the shaft; the cam being movable between a clamping position at which the clamp draws the shaft to move the second terminal portion toward the first terminal portion and a releasing position at which the cam permits the shaft to shift to move the second terminal portion away from the first terminal portion to release the bushing from securing the other rod; said first part comprising a case extending around the bushing; the shaft extending from the second terminal portion past the first terminal portion and out of the case past the first terminal portion; the cam being located outside the case beyond the first terminal portion; the cam engaging the case beyond the first terminal portion upon movement of the cam between the clamping and released positions thereof; the cam being shaped for moving the shaft for moving the second terminal portion with respect to the first terminal portion as the cam moves between the clamped and released positions; the case being shaped for being engaged by the first terminal portion as the shaft draws the second terminal portion toward the first terminal portion; and said cam being journaled to the shaft at a pivot axis across the shaft; the cam including a first cam surface which is at a relatively greater distance from the pivot axis and a second cam surface which is at a relatively lesser distance from the pivot axis; wherein with the first cam surface engaging the case, the shaft being drawn to move the second terminal portion toward the first terminal portion, and with the second cam surface engaging the case, the shaft being permitted to shift to permit the first and second terminal portions to separate.