Self-locking hydraulic pivot device for interconnecting a support cage to a boom

摘要

A hydraulic pivot device for pivotally connecting a support housing to a boom of the type secured to a vehicle. The hydraulic pivot device comprises a main housing having a gear-engaging piston which is axially displaceable in a piston cylinder provided therein. The piston has opposed piston heads and is sealingly displaced placed in the piston cylinder by fluid pressure applied at a selected one of opposed ends of the piston cylinder. The piston is also positively interlocked by the use of lock valves which are port-mounted at each end of the piston cylinder. A drive shaft having a drivable pinion gear is supported within the housing with a drivable pinion gear being in toothed engagement with a toothed section of the piston so that axial displacement of the piston wall impact axial rotation to the drive shaft. The drive shaft has a connection section exteriorly of the housing which is in engagement with a connector element which is secured to the support housing for imparting controlled displacement thereof.