Animal waste pumping system

In an animal waste pumping system of the type including (1) a hopper for the collection of waste material (2) a lower housing attached to the hopper, (3) a pumping chamber within the lower housing, (4) a hollow piston reciprocable within the pumping chamber, and (5) drive means for reciprocating the hollow piston (a) through a pumping stroke during which waste material is pumped out of the hopper into discharge piping connected to receive waste material from the pumping chamber and (b) through a return stroke during which waste material from the hopper enters into and flows through the hollow piston for subsequent pumping, the hollow piston having a first end with pivotable gate means extending thereacross that close during the pumping stroke and open during the return stroke and an open second end, and the drive means including a pair of spaced driving arms connected to the hollow piston through the open second end thereof,

• the improvement wherein:
• the pumping chamber includes
• (1) a rear mounting plate adapted for attachment to the lower housing,
• (2) a cylindrical tube attached to and extending from the rear mounting plate,
• (3) a spacer plate secured to the cylindrical tube remote from the rear mounting plate and adapted to contact the interior of the lower housing to space the tube therefrom, and
• (4) backflow gate means pivotally mounted on the spacer plate and adapted to open during the pumping stroke of the hollow piston and close during the return stroke thereof, and
• the pumping chamber is removable from the lower housing as a unitary assembly including the rear mounting plate, cylindrical tube, spacer plate and backflow gate means.

In an animal waste pumping system of the type including (1) a hopper for the collection of waste material, (2) a lower housing attached to the hopper, (3) a pumping chamber within the lower housing, (4) a hollow piston reciprocable within the pumping chamber, and (5) drive means for reciprocating the hollow piston (a) through a pumping stroke during which waste material is pumped out of the hopper into discharge piping connected to receive waste material from the pumping chamber and (b) through a return stroke during which waste material from the hopper enters into and flows through the hollow piston for subsequent pumping, the hollow piston having a first end with pivotable gate means extending thereacross that close during the pumping stroke and open during the return stroke and an open second end, and the drive means including a pair of spaced driving arms connected to the hollow piston through the open second end thereof,

• the improvement wherein:
• (A) a plurality of paddles are connected across the driving arms of the drive means and adapted to agitate waste material in the hopper and aid in transfer of waste material into the hollow piston;
• (B) the pumping chamber includes,
• (1) a rear mounting plate adapted for attachment to the lower housing,
• (2) a cylindrical tube attached to and extending from the rear mounting plate,
• (3) a spacer plate secured to the cylindrical tube remote from the rear mounting plate and adapted to contact the interior of the lower housing to space the tube therefrom, and
• (4) backflow gate means pivotally mounted on the spacer plate and adapted to open during the pumping stroke of the hollow piston and close during the return stroke thereof;
• and
• (C) the hollow piston is a cylindrical element reciprocable within the cylindrical tube of the pumping chamber and includes,
• (1) antifriction bearing rings attached to its outer surface and along which the hollow piston is journalled inside the cylindrical tube, and
• (2) annular sealing means along its outer surface and arranged to reduce sprayback of waste material between said outer surface and the cylindrical tube of the pumping chamber.