Screw actuated jack means

Claim 1

A JACK OF THE CHARACTER DISCLOSED COMPRISING IN COMBINATION AN OUTER TUBE, AN INNER TUBE SLIDABLY TELESCOPED IN THE OUTER TUBE, MEANS FOR SECURING THE OUTER TUBE AT A PLURALITY OF SPACED POINTS ON AN OBJECT TO BE RAISED AND LOWERED, AN ELONGATED SCREW IN THE JACK HAVING ITS UPPER END ADJACENT THE UPPER END OF THE OUTER TUBE AND EXTENDING DOWNWARDLY THEREIN AND INTO THE INNER TUBE, A NUT THREADEDLY RECEIVING THE SCREW, THE NUT HAVING A POLYGONAL EXTERIOR AND BEING RIGIDLY MOUNTED IN THE UPPER END OF THE INNER TUBE, A DRIVE MEMBER SECURED TO THE UPPER END OF THE SCREW AND JOURNALLED ON THE UPPER END OF THE OUTER TUBE, SAID DRIVE MEMBER HAVING AN UPWARDLY OPENING POLYGONAL SOCKET, AND A MANUALLY OPERABLE POWER UNIT DETACHABLY MOUNTED ON THE JACK AND HAVING ONE POINT OF CONNECTION WITH THE EXTERIOR OF THE OUTER TUBE AND HAVING A DRIVING ELEMENT DETACHABLY MOUNTED IN SAID SOCKET IN THE DRIVE MEMBER ON THE SCREW MEANS, SAID POWER UNIT HAVING A MANUALLY OPERABLE CRANK MEANS, AND A DRIVE TRANSMITTING ELEMENT BETWEEN THE CRANK MEANS AND THE DRIVING ELEMENT, SAID DRIVING ELEMENT ALSO CONSTITUTING ONE OF THE MEANS FOR RETAINING THE POWER UNIT ON THE REMAINDER OF THE JACK.