Power adapter for landing gear of semi-trailers

Claim 1

IN A POWER ADAPTER, (A) A CASING, (B) AN UPPER SPROCKET JOURNALED IN AN UPPER PORTION OF THE CASING FOR ROTATION IN A SUBSTANTIALLY VERTICAL PLANE, (C) A LOWER SPROCKET IN THE LOWER PORTION OF THE CASING IN SUBSTANTIALLY VERTICAL ALINEMENT WITH THE UPPER SPROCKET, (D) A STUD HAVING A SUBSTANTIALLY HORIZONTAL AXIS ON WHICH THE LOWER SPROCKET ROTATES, (E) A CONTROL SHAFT ALSO HAVING A SUBSTANTIALLY HORIZONTAL AXIS BUT SPACED BELOW THE AXIS OF THE STUD, (F) A ROCKER ARM AFFIXED AT ITS LOWER PORTION TO THE CONTROL SHAFT, UPSTANDING FROM THE CONTROL SHAFT AND CARRYING THE STUD AT ITS UPPER PORTION, (G) A FLEXIBLE CHAIN CONNECTING THE SPROCKETS AND IN THE LOWER PORTION OF WHICH THE LOWER SPROCKET IS ADAPTED TO BODILY SWING IN AN ARC HAVING THE AXIS OF THE CONTROL SHAFT AS ITS CENTER OF MOTION, (H) A DRIVE PINION, (I) AN IDLER PINION, (J) MEANS TO ROTATE SAID PINIONS IN OPPOSITE DIRECTIONS, (K) SAID LOWER SPROCKET HAVING AN INTERNAL RING OF GEAR TEETH ADAPTED TO BE BROUGHT SELECTIVELY INTO MESH WITH THE TEETH OF THE DRIVE AND IDLER PINIONS UPON MOVEMENT OF SAID LOWER SPROCKET IN ITS ARC OF MOVEMENT, AND (L) MEANS TO IMPART MOVEMENT TO THE CONTROL SHAFT TO ACTUATE SAID ROCKET ARM SO THAT SAID LOWER SPROCKET IS SWUNG IN ITS ARC OF MOVEMENT.