Adjustable stretcher

Claim 1

A STRETCHER COMPRISING AN UPRIGHT FRAME, A BED ABOVE SAID FRAME, COMBINED SUPPORT AND ADJUSTMENT MEANS FOR SAID BED INCLUDING VERTICALLY DISPOSED SCREW SHAFTS CONNECTED TO SAID BED AND DEPENDING THEREFROM, A NUT HAVING A SPROCKET WHEEL RIGID THEREWITH AND IN SCEW THREADED ENGAGEMENT WITH EACH SCREW SHAFT, MEANS TO MOUNT EACH NUT UPON SAID FRAME AND RETAIN SOME AGAINST AXIAL MOVEMENT, MEANS FOR SELECTIVELY ROTATING SAID AGAINST TO EFFECT BED ADJUSTMENT, SAID LAST MEANS COMPRISING SPROCKET AND CHAIN CONNECTIONS TO SAID SPROCKET WHEELS, DRIVING MEANS FOR SAID SPROCKET AND CHAIN CONNECTIONS COMPRISING A PAIR OF DRIVING SPROCKET WHEELS, CHAINS CONNECTING EACH DRIVING SPROCKET WITH NUT CARRYING SPROCKET WHEELS ARRANGED RESPECTIVELY FORE AND AFT OF THE STRETCHER BED SO THAT ROTATION OF ONE DRIVING SPROCKET WHEEL IN ONE DIRECTION RAISES ONE END OF THE BED AND IN THE OPPOSITE DIRECTION LOWERS SAID END OF THE BED, AND ROTATION OF THE OTHER DRIVING SPROCKET WHEEL RAISES OR LOWERS THE OPPOSITE END OF THE BED IN ACCORDANCE WITH THE DIRECTION OF ROTATION, AND CONJOINT ROTATION OF BOTH DRIVING SPROCKET WHEELS RAISES OR LOWERS THE BED IN THE POSITION TO WHICH IT HAS PREVIOUSLY BEEN ADJUSTED, AND COMMON MEANS FOR ACTUATING SAID DRIVING SPROCKET WHEELS TOGETHER OR FOR ACTUATING ONE OR THE OTHER OF SAID DRIVING SPROCKET WHEELS.