Abstract: A pull out step assembly is provided to assist in climbing into or out of a cab of a crane, excavator or similar vehicle. The step assembly includes a pair of brackets carrying forward and rearward rollers and a step having support guides for embracing the rollers to prevent the step from shifting laterally during use. A locking mechanism positively secures the step in place in both the extended and retracted positions. The locking mechanism includes an operating shaft having a pivotal handle positioned below the step for easy access and a dual crank. The crank receives the ends of a pair of reciprocal locking rods that extend transversely to engage corresponding pairs of forward and rearward slots formed in the brackets. A compression spring supplies a biasing force to keep the rods engaged in the slots. To shift the step, the handle is manually rotated either clockwise or counterclockwise to overcome the biasing force and disengage the rods from the respective slots.

Abstract: A suspension system for a heavy duty crane, excavator or the like is provided with a transverse rear axle and semi-independent suspension by hydraulic cylinders. The cylinders are pivotally attached adjacent the ends of the axle to allow oscillation in a traveling mode simulating a bolster, center pinned type system. The extend sides of the cylinders transfer hydraulic oil through an exchange line to accommodate true oscillation movement. In a working mode, locking valves block the flow of oil between the cylinders to establish a stabilized platform. A hydraulic/pneumatic accumulator communicates with the exchange line in the travel mode for cushioning of the ride. A third locking valve in a bypass return line communicating with the retract sides of the cylinders blocks the oil flow back to the reservoir in the working mode, but upon release by the control circuit is opened to communicate with the reservoir and maintain back pressure to enhance oscillation and prevent cavitation.

Abstract: A flameless heater for operator's cab having automatic heat control. A hydraulic pump provides pressurized fluid which flows through a fluid restrictive orifice to produce thermal energy and raise fluid temperature as a result of a drop in hydraulic pressure. The heated fluid flows through a heat exchanger where a fan blows air over the exchanger to provide hot air for the operator's cab. A spool valve connected in parallel with the orifice bypasses fluid around the orifice to limit the rise in fluid temperature. A temperature sensor selectively opens and closes the spool valve to keep fluid temperature within a high temperature limit and a low temperature limit.

Abstract: An aerial platform attachment for a crane having an extensible boom including a basket pivotally suspended from the boom tip. A loop on the bucket is engaged by a projection secured to the boom when the bucket is pivoted adjacent the boom and the boom is then fully retracted. A brake which is applied by a hand lever movable in either direction from a central release position locks the bucket relative to the boom when in a working position.

Abstract: This invention relates to aerial platforms capable of accommodating two occupants, and more particularly, to such devices which are especially suited for use with a hydraulic crane.