Patent ID: 6182575
Filing Date: 2001-02-06
Classification: B61K,F16F

Abstract:
An adjustable stop-wagon retarder with locking function for a wagon at high speed including a sliding cylinder assembly and a housing assembly having an exhaust unit, the sliding cylinder assembly comprising a cylinder having an upper end and a lower end; a piston slidably housed in said cylinder and dividing the cylinder into an upper chamber and a lower chamber; a pressure valve and a locking control valve both disposed coaxially with said piston; an unlocking unit; at least one uni-directional return unit installed on the piston and a sealing gland mounted on the lower end of the cylinder; said sliding cylinder assembly being charged with hydraulic oil and nitrogen and can longitudinally reciprocate between an upper position and a lower position, a portion of said sliding cylinder being disposed in the path of a wheel of said wagon for retarding the speed of said wagon when said wheel engages said portion,said uni-directional unit comprising a sealing valve plate and at least one adjustable throttle valve, the sealing valve plate and a pressure valve seat being mounted coaxially on the upper part of the piston with an adjustable gap between the valve plate and the valve seat, the adjustable throttle valve being disposed under the valve plate for controlling the speed of the hydraulic oil returning to the upper chamber from the lower chamber of the cylinder, the sealing valve plate being longitudinally movable along the axis of the piston between the valve seat and adjustable throttle valve; said adjustable throttle valve comprising a throttle orifice, a ball removably disposed in the throttle orifice, and a biasing member removably disposed in the throttle orifice between the ball and the sealing valve plate biasing the ball towards a closed position, the biasing member having a spring force selected to control the speed of movement of the cylinder from the lower position to the upper position;said locking control valve comprising a switch valve and at least one positioning unit, said control valve being disposed around the piston between the head of the piston and the sealing gland and rotatable between an unlocked position in which at least one flowing orifice on the switch valve is aligned with the adjustable throttle valve and a locked position in which the flowing orifice is shut off from the throttle orifice, said unlocked position and said locked position being limited by at least one positioning unit; the switch valve comprising at least one locking oblique, an unlocking oblique, the flowing orifice and a leaking orifice, the locking oblique being impacted by the hydraulic oil from a piston outlet so that the switch valve rotates in one direction towards the locked position when the wagon travels at a speed higher than a predetermined value; the leaking orifice being aligned with the adjustable throttle valve in the locked position so that the hydraulic oil can slowly return to the upper chamber from the lower chamber, and therefore, the cylinder can slowly return to its upper position; and the unlocking oblique cooperating with said unlocking unit so that the switch valve rotates in a direction opposite said one direction towards the unlocked position.