Patent ID: 6305916
Filing Date: 2001-10-23
Classification: F04B,Y10S

Abstract:
A concrete pump comprising:a frame,a hydraulic pump mounted on the frame,a pair of parallel concrete pumping cylinders mounted on the frame, each of the pumping cylinders having an outlet end,a valve and a hopper assembly pivotally mounted on the frame for movement between open and closed positions, the valve and hopper assembly including a hopper having an outlet opening and a front wall with a pair of pump openings which are aligned with the outlet ends of the pumping cylinders when the hopper assembly is in the closed position, an S-shaped valve tube pivotally mounted in the hopper and having a first end aligned with the outlet opening of the hopper and a second end which is movable between a first position in which the second end is aligned with one of the pumping openings and a second position in which the second end is aligned with the other of the pumping openings, a mounting plate on the second end of the valve tube, a shaft connected to the mounting plate and extending through the front wall of the hopper, and a crank arm attached to the shaft outside of the hopper,a hydraulic piston mounted on the valve and hopper assembly and connected to the crank arm for moving the valve tube between the first and second positions,a hydraulic hose connecting the hydraulic piston to the hydraulic pump, anda pair of O-rings on the frame, each of the O-rings surrounding the outlet end of one of the pump cylinders and being engageable with the hopper when the hopper is in the closed position for providing seals between the pumping cylinder and the pump.