Collapsible and adjustable trestles

Claim 1

A TRESTLE CONSISTING OF TWO UPRIGHTS AND A BAR, EACH UPRIGHT BEING FORMED OF TWO LIKE SPACED FRAME MEMBERS EACH CONSISTING OF A HORIZONTAL PORTION AND A DOWNWARDLY EXTENDING PORTION AND AN INTERMEDIATE ARCUATE PORTION, THE HORIZONTAL PORTIONS BEING MUTUALLY PARALLEL, VERTICALLY SPACED RIGID TRANSVERSE MEMBERS JOINING THE LEG PORTIONS, EACH UPRIGHT HAVING ALIGNED DEPENDING BRACKETS EXTENDING FROM SAID HORIZONTAL PORTIONS THEREOF, A CROSS-MEMBER SUPPORTED BY THE ALIGNED BRACKETS OF EACH UPRIGHT, ONE OF SAID TRANSVERSE MEMBERS BEING POSITIONED AT SUBSTANTIALLY THE UPPER EXTREMITIES OF THE LEG PORTIONS AND ON THAT SIDE OF THE LEG PORTIONS WHICH FACES SAID CROSS-MEMBER, SAID ONE OF SAID TRANSVERSE MEMBERS HAVING A FIRST VERTICAL CLAMP JAW EXTENDING UPWARD THEREFROM AND SPACED BETWEEN SAID HORIZONTAL PORTIONS, A SUPPORT SECURED TO SAID ONE OF SAID TRANSVERSE MEMBERS AND HAVING A SCREW ROTATABLY MOUNTED THEREIN AT RIGHT ANGLES TO SAID JAW, A SECOND UPWARDLY EXTENDING VERTICAL CLAMP JAW POSITIONED BETWEEN SAID HORIZONTAL PORTIONS SLIDABLY MOUNTED ON SAID SUPPORT AND THREADED ON SAID SCREW AND TOGETHER WITH SAID FIRST JAW FORMING A CLAMP, AND AN ADDITIONAL RIGID TRANSVERSE MEMBER SECURED TO THE ENDS OF THE HORIZONTAL PORTIONS, THE ENDS OF SAID BAR BEING POSITIONED ON EACH UPRIGHT BETWEEN SAID ONE TRANSVERSE MEMBER AND SAID ADDITIONAL MEMBER AND BETWEEN SAID JAWS OF THE CLAMP AND RESTING ON SAID ONE TRANSVERSE MEMBER AND ON SAID CROSSMEMBER.