Abstract: An interlock arrangement for use with a sideloader fork lift truck includes a solenoid valve which when electrically energized is "open" to dump to sump hydraulic fluid from the output line of the hydraulic pump, whereby to prevent passage to the clutches of the power shift transmission of the pressurized hydraulic fluid from the pump, thereby rendering the power shift transmission ineffective to transmit motive power from the engine to the drive wheels of the sideloader vehicle. A limit switch is stationarily mounted contiguous the piston portion of each stabilizing jack, each limit switch being a normally closed switch which is adapted to be open only when the piston portion is in a predetermined properly retracted position.

Abstract: A side loader main frame includes front and rear sections which are rigidly interconnected by a bridge to form a pocket for a laterally traversing mast. The bridge is a boxlike torque tube with openings in the laterally inner vertical wall through which transversely extending guide structures for the traversing mast extend. The traversing mast has a pair of supports with rollers which extend into the openings upon lateral retraction of the mast, thereby permitting the uprights of the mast to be closely adjacent to the bridge. The bridge includes a pair of laterally spaced and longitudinally extending vertical walls, horizontally disposed top and bottom walls and a pair of horizontal intermediate walls spaced above and below the openings, respectively. The frame is constructed to obtain great strength and yet keep the bridge relatively narrow in lateral width.