| 摘要 |
A double-acting regeneratively controlled piston-cylinder device or tilt cylinder for tilting a spring-supported truck cab relative to the truck chassis to permit access to the truck engine positioned below the cab embodies means therein which enable slight relative reciprocating movement of the piston and cylinder from an "at rest" position in response to slight relative bouncing movement of the cab with respect to the chassis as the truck operates over-the-road. The piston-cylinder device is of the double-acting type and embodies means to provide an oil passage around the piston over part of the piston stroke. The oil passage may take the form of a concentric chamber, an eccentric chamber, a helical groove, or a longitudinal groove, each formed in the cylinder wall or may be a separate tube on the cylinder for by-passing the piston. Relative piston-cylinder motion results because, if the piston is pushed inwardly of the cylinder by cab bounce, oil can escape from the base end of the cylinder via the passage to the rod end of the cylinder. Or, if the piston is pulled outwardly of the cylinder by cab bounce, oil can flow from the rod end of the cylinder via the passage to the base end of the cylinder. |
