Self-leveling device with clamping means for adjusting initial spring tension

Claim 1

IN A SELF-LEVELING DEVICE COMPRISING, A BASE MEMBER, AN UPRIGHT FRAME SUPPORTED BY SAID BASE MEMBER, VERTICALLY MOVABLE CARRIAGE MEANS RETAINED WITHIN SAID FRAME, A PLATFORM SUPPORTED BY SAID CARRIAGE MEANS FOR THE RECEIPT OF ARTICLES THEREON, ROTATABLE MEANS ASSOCIATED WITH SAID UPRIGHT FRAME, CARRIAGE SUPPORTING CARRIER MEANS DISPOSED UPON SAID FRAME, A ROTATABLE SHAFT HOUSED WITHIN SAID CARRIAGE SUPPORTING CARRIER MEANS, A PULLEY AFFIXED TO SAID ROTATABLE SHAFT, A FLEXIBLE BAND SUPPORTING SAID CARRIAGE, SAID BAND COMMUNICATING BETWEEN SAID ROTATABLE MEANS AND SAID PULLEY, A COILED TORSION SPRING DISPOSED ON SAID SHAFT TO BIAS THE LATTER AND DRUM MEANS IN WHICH SAID SHAFT IS MOUNTED FOR ROTATION, THAT IMPROVEMENT WHICH COMPRISES MEANS INCLUDING SAID SPRING FOR EFFECTING AN OPERATIVE CONNECTION BETWEEN SAID SHAFT AND SAID DRUM MEANS, MEANS MOUNTING SAID DRUM MEANS FOR ROTATION RELATIVE TO SAID SHAFT FOR IMPARTING AN INITIAL DEFLECTION TO SAID SPRING, AND MEANS FOR RELEASABLY CLAMPING SAID DRUM MEANS IN A ROTATABLY ADJUSTED POSITION THEREOF FOR RETAINING SAID INITIAL DEFLECTION OF SAID SPRING.