초록

A cushion valve for a hydraulic piston. The valve includes two inlet ports each connected into the same end of the cylinder. One port leads directly to an outlet while the second port feeds to the outlet through a floating, restricted flow orifice to provide a cushioning effect for the piston.

대표청구항 ▼

In a cylinder having a fluid actuated piston therein, said piston being shiftable longitudinally within said cylinder by the operation of said fluid, the improvement wherein said cylinder includes two ports at one end for evacuating fluid from in front of said piston as it is urged toward said one c

In a cylinder having a fluid actuated piston therein, said piston being shiftable longitudinally within said cylinder by the operation of said fluid, the improvement wherein said cylinder includes two ports at one end for evacuating fluid from in front of said piston as it is urged toward said one cylinder end and for introducing fluid at the rear of said piston to urge it away from said one cylinder end, said cylinder ports being spaced longitudinally apart along the direction of travel of said piston within said cylinder with one port nearer said cylinder end than the other port, said piston being shiftable over said other cylinder port, a valve for evacuating and introducing fluid from and into said one cylinder end, said valve having first, second and third passages, each of said first and second passages in spaced communication with said third passage in the valve, a fluid flow restrictor means within said third valve passage and shiftable therein in response to fluid flow from a non-operative position to an operative position between said first and second passages for reducing the rate of fluid flow from said first valve passage into said third valve passage, said first valve passage in communication with said one cylinder port, said second valve passage in communication with said other cylinder port whereby fluid will first flow through both said first and second valve passages and out said third valve passage as the piston approaches said one cylinder end and then flow only through said first and third valve passages at a reduced rate after said piston shifts over said other cylinder port to provide a cushioning resistance to the movement of said piston.