Pump for semi-fluid materials

Claim 1

A pump comprising a supply hopper and a pair of pump cylinders each having a front end with an opening thereat and a piston operable during its charging strokes to induct material from the hopper into its cylinder through said opening, and operable during its discharge strokes to expel material from its cylinder through said opening, characterized by: A. the pump cylinders being mounted side by side with their axes substantially horizontal and their front ends adjacent to the underside of the hopper; B. a manifold connected with the front ends of the cylinders and having the hopper mounted thereon, said manifold having 1. a pair of outlet passages, one for each cylinder and communicating with said opening thereof to conduct material expelled from the cylinder to delivery means, 2. and a pair of inlet passages, one for each cylinder and communicating with said opening thereof, each of said inlet passages opening upwardly to the interior of the supply hopper; C. valve means rotatable on an axis which is inclined upwardly and forwardly with respect to the cylinder axes, and passes through said manifold D. said manifold having a forwardly facing surface that is substantially perpendicularly intersected by the upwardly and forwardly inclined axis about which said valve means turns and which has a pair of apertures therein each defining the forward ends of said inlet and outlet passages For one of the cylinders, said manifold surface being intersected by the cylinder axes; and E. said valve means having passage blocking lobe structure in surface-to-surface contiguity with said surface on the manifold.