an adjustable surgical retractor system for clamping system to an operating table . the clamping mechanism includes an upper jaw , lower jaw , a drive member , an adjustable frame support post and releasable locking mechanism for adjusting the height of the surgical retracting frame . the releasable locking mechanism can be a mechanism that includes a sleeve in close sliding relationship to the upper portion of lower jaw member . the upper portion of the lower jaw has a plurality of sockets for receipt of a plurality of balls . the sleeve can have a first position which positions an internal shoulder in alignment with the sockets and urges the balls into engagement with circumferential grooves in post member to lock the post at desired height . in a second position , an internal groove in the sleeve can align with the sockets to allow the balls to move partially out of the sockets and out of engagement with the groove in the post so that the post can be longitudinally adjusted relative to the clamping mechanism .