Concrete pumping apparatus

Abstract

Concrete pumping apparatus of the positive displacement type in which primary and secondary pumping units are actuated in a manner such that the pumping discharges from the pumping units overlap in a manner to produce a substantially constant flow delivery, the pumping units having pistons operably connected to a pivoted rocker arm having a driving connection with a main shaft, and another overriding driving connection with the main shaft which varies the driving action of the rocker arm, wherein the pivot of the rocker arm is supported on a swingable lever having its outer end operably engaged with rotatable cam means carried by the main shaft. A manifold housing connected to the similar open ends of the cylinders of the pumping units, contains valve members for controlling the pumping operations so that one pumping unit serves as a primary unit to initially discharge the pumped material concurrently into a delivery line and into the cylinder of the other pumping unit which then operates as a secondary pumping unit to discharge its previously received material into the delivery line. The manifold housing is further provided with access means permitting removal of the valve members for cleaning, replacement, repair, etc., without having to disassemble the manifold housing. The apparatus also includes a hinged material delivery spout on the manifold housing with latching means which may be initially actuated to permit hinged movement of the spot to a partially opened latched position to relieve the pressurized material therein, prior to its being completely unlatched for hinged movement to a fully opened position.