Retractable undercarriage for airplanes

Claim 1

FOR USE WITH AN AIRPLANE FIXED STRUCTURE, AN UNDERCARRIAGE UNIT WHICH COMPRISES, IN COMBINATION, A RIGID MEMBER PIVOTED TO SAID AIRPLANE STRUCTURE ABOUT A SINGLE FIRST AXIS TRANSVERSE TO THE FORE-AND-AFT DIRECTION OF THE AIRPLANE, A WHEEL, A RIGID WHEEL SUPPORT, A SHOCK ABSORBING STRUT PIVOTED AT ONE END TO SAID RIGID MEMBER ABOUT A SINGLE SECOND AXIS AND AT THE OTHER END TO SAID WHEEL SUPPORT ABOUT A SINGLE THIRD AXIS, RESPECTIVELY, BOTH OF SAID SECOND AND THIRD AXES BEING TRANSVERSE TO THE FOREAND-AFT DIRECTION OF THE AIRPLANE, SAID STRUT EXTENDING ALONG A LINE INTERSECTING SAID FIRST AND SECOND AXES TRANSVERSELY THERETO WHEN THE UNDERCARRIAGE UNIT IS IN THE DOWN POSITION, A HYDRAULIC ACTUATOR FOR RETRACTING SAID STRUT, SAID ACTUATOR INCLUDING TWO ELEMENTS TELESCOPICALLY MOVABLE WITH RESPECT TO EACH OTHER, ONE OF SAID ELEMENTS BEING PIVOTED TO SAID AIRPLANE STRUCTURE AND THE OTHER OF SAID ELEMENTS BEING PIVOTED TO SAID RIGID MEMBER ABOUT A FOURTH SINGLE AXIS AND A FIFTH SINGLE AXIS, RESPECTIVELY, BOTH TRANSVERSE TO THE FORE-AND-AFT DIRECTION OF THE AIRPLANE, SAID WHEEL SUPPORT BEING A LEVER PIVOTABLE ABOUT SAID THIRD AXIS, SAID WHEEL BEING JOURNALLED IN SAID LEVER AT ONE END THEREOF, A ROD PIVOTED AT ONE END TO THE SAID LEVER AND AT THE OTHER END DIRECTLY TO SAID AIRPLANE STRUCTURE ABOUT RESPECTIVE AXES TRANSVERSE TO THE FORE-AND-AFT DIRECTION OF THE AIRPLANE, AND A RIGID LINK PIVOTED AT ONE END TO AN INTERMEDIATE POINT OF SAID ROD AND AT THE OTHER END TO SAID RIGID MEMBER ABOUT RESPECTIVE AXES TRANSVERSE TO THE FORE-AND-AFT DIRECTION OF THE AIRPLANE.