Abstract: A vehicle suspension lock system for a tree feller-buncher comprising a pair of pivot arms extending transversely from a vehicle frame. Track pods are mounted on the outer end of each pivot arm and a hydraulic cylinder is extensibly disposed between the frame and the pivot arm. A pilot-operated check valve in each cylinder prevents upward movement of the rod in its associated cylinder when the check valve is closed. The pilot port of each check valve is pressurized responsive to hydraulic fluid pressure used to drive the vehicle track pods thereby permitting fluid flow into and between the cylinders when the vehicle is moving and checking the flow from each cylinder when the vehicle is stationary to effect locking of the pivot arms for logging operations.

Abstract: A four track vehicle especially adapted for logging on steep slopes includes a running unit and an upper unit. The upper unit is articulated relative to the lower unit to maintain a center of gravity within the four tracked pods upon which the running unit is mounted. Sensing systems are utilized to alert the operator when the machine is in an incipient tipping condition. Moreover, a unique suspension system combining a torsion frame and swingable pod mounting arms are employed. The pods are locked in position when the vehicle is in an operating mode and are unlocked when the vehicle is in a travel mode.

Abstract: A four track vehicle especially adapted for logging on steep slopes includes a running unit and an upper unit. The upper unit is articulated relative to the lower unit to maintain a center of gravity within the four tracked pods upon which the running unit is mounted. Sensing systems are utilized to alert the operator when the machine is in an anticipitated tipping condition. Moreover, a unique suspension system combining a torsion frame and swingable pod mounting arms are employed. The pods are locked in position when the vehicle is in an operating mode and are unlocked when the vehicle is in a travel mode.

Abstract: An extensible lifting spreader frame for handling cargo containers comprises a pair of oppositely extending beam arms slidably received within a central pair of side-by-side connected sleeve beams. Beam cross arms at the outer ends of the sleeve beams mount twist-lock latching hooks at their opposite ends for attachment to the four socketed top corners of a cargo container for lifting the same. The frame is suspended from an overhead crane by four flexible suspension cables connected to the opposite ends of the cross arms. A pair of actuating cables operated from the crane operates mechanical cam-operated latch actuating mechanism. A pull cable, also operated from the crane, operates with pulleys on the sleeve beams to extend the beam arms from their retracted positions. Manually operable mechanism, also on the sleeve beams, inserts locking pins into aligned holes in the sleeve beams and beam arms to lock the arms in adjusted positions.