Adjustable desk and chair

Claim 1

AN ADJUSTABLE HEIGHT MECHANISM FOR TABLES AND CHAIRS HAVING AT LEAST TWO LEGS COMPRISING AN UPPER LEG PORTION AND A LOWER LEG PORTION FOR EACH LEG, THE UPPER PORTION BEING TELESCOPICALLY DISPLACEABLE RELATIVE TO THE LOWER PORTION; A SCREW SPINDLE ROTATABLY ATTACHED WITHIN THE UPPER LEG PORTION AT ITS UPPER END AND EXTENDING INTO THE LOWER LEG PORTION, THE SPINDLE BEING THREADEDLY MOUNTED ON A NUT FIXED TO THE UPPER END OF THE LOWER LEG PORTION; SHAFT PIN RECEIVING MEANS AT THE UPPERMOST END OF SAID SPINDLE; AND A REMOVABLE TRANSMISSION MECHANISM ENCLOSED IN A SEPARATE CASING AND COMPRISING AT LEAST TWO SHAFT PINS PROJECTING FROM BELOW SAID CASING FOR SIMULTANEOUS ENGAGEMENT WITH THE RESPECTIVE PIN RECEIVING MEANS OF THE SPINDLES, AND POWER TRANSMITTING MEANS WITHIN THE CASING FOR SIMULTANEOUS ROTATION OF THE PINS, THE POWER TRANSMITTING MEANS COMPRISING A SHAFT FIXED TO EACH OF THE SHAFT PINS AT ONE END THEREOF, BUSHINGS ROTATABLY ATTACHING EACH SHAFT TO THE CASING, EACH SHAFT BEING LONGITUDINALLY DISPLACEABLE IN THE CASING, A SPROCKET WHEEL FIXED TO EACH SHAFT, A CHAIN DRIVE JOINING THE SPROCKET WHEEL, CRANK RECEIVING MEANS AT THE OTHER END OF AT LEAST ONE SHAFT, AND CATCH MEANS PREVENTING ROTATION OF THE PINS WHEN THE TRANSMISSION MECHANISM IS REMOVED.