Abstract: A forklift truck having a fork assembly connected to a telescopic auxiliary boom articulated to a telescopic main boom. The telescopic and articulating features of the auxiliary boom in conjunction with the telescopic feature of the main boom increases the range and reach of the fork assembly to above ground heights and to below ground depths.

Abstract: An extremely massive mobile crain counterweight requiring demounting from the crane rotary superstructure for separate transport or storage has self-contained raising and lowering mechanism which may be powered from the crane carrier and which forms a part of the counterweight mass. The internal counterweight mechanism is shielded from ballast, such as shot, which fills the interior of the counterweight. A foot plate forming a part of the raising and lowering mechanism of the counterweight is lockable in extended and retracted positions and is constructed for interlocking engagement with a locator structure on the crane carrier. An efficient and simplified sequence of counterweight manipulating steps is enabled.

Abstract: Fluid links are interposed between manual levers which control the motions of a machine such as a construction crane and associated spool valves which regulate the machine motions. In normal operation within predetermined safe limits of machine motions, pressurized fluid delivery valve means connected with the fluid links is conditioned by a normal signal from a safe machine motion sensing means and delivers pressurized fluid to the fluid links rendering the links "hard" so that the manual levers are enabled to effect safe machine motions. When an unsafe machine motion is sensed by the sensing means, the valve means responds to the interruption of the normal signal from the sensing means and is conditioned to interrupt delivery of pressurized fluid to the fluid links thus rendering the links "soft" and thus disabling the manual levers from causing machine motions beyond safe limits.