Underfloor lathe for reconditioning railway vehicle wheels

Claim 1

IN A UNDERFLOOR LATHE FOR MACHINING THE PERIPHERAL SURFACE OF A WHEEL OF A RAILWAY VEHICLE IN ASSEMBLED CONDITION, THE COMBINATION COMPRISING A ROLLER HOLER, A PAIR OF ROLLER MOUNTED THEREON FOR ROTATION ABOUT PARALLEL HORIZONTAL AXES TO ENGAGE AND SUPPORT SAID WHEEL, DRIVING MEANS CONNECTED WITH SAID ROLLERS FOR IMPARTING ROTATION THERETO TO THEREBY TURN SAID WHELL, A TOOL HOLDER DISPOSED BETWEEN SAID ROLLERS FOR SUPPORTING A CUTTING TOOL SO AS TO ENGAGE SAID WHEEL BELOW ITS AXIS, A MOVABLE JACK CARRYING ONE OF SAID HOLDERS FOR VERTICAL MOVEMENT, ADJUSTABLE MEANS FOR KEEPING THE OTHER ONE OF SAID HOLDERS AT A FIXED BUT ADJUSTABLE LEVEL, A STATIONARY BRACKET, SENSING MEANS MOUNTED ON SAID BRACKET AND COORDINATED TO THE AXLE OF SAID WHEEL FOR SENSING THE LEVEL AT WHICH THE ROTARY AXIS OF SAID WHEEL IS LOCATED, AND MEANS CONTROLLED BY SAID SENSING MEANS AND CONNECTED WITH SAID JACK TO EFFECT MOVEMENT OF SAID JACK THEREBY TO MOVE SAID ONE OF SAID HOLDERS SO AS TO MAINTAIN THE VERTICAL DISTANCE BETWEEN SAID CUTTING TOOL AND SAID LEVEL CONSTANT, WHILE SAID WHEEL IS TURNED BY SAID ROLLERS, IRRESPECTIVE OF A NON-CIRCULAR CONDITION OF THE PERIPHERY OF SAID WHEEL.