Manually operated pump assembly

Abstract

A manually operated pump exhibiting numerous improvement over existing such pumps is described. The pump can include a cylinder that is removeably mounted to a molded valve box of unitary construction. The valve box can feature a valve plate covering a valve chamber and housing an inlet valve and an outlet valve. In some instances, the pump includes a molded piston of unitary construction to which a pair of opposing piston cups is mounted. In some cases, the pump includes a filler cap forming an inlet adapted to deliver a priming fluid into the cylinder. In some cases, the pump includes a stopper cap adapted to prevent a pump shaft from being fully pulled out of the cylinder.

What is claimed is: 
     
         1 . A manually operated pump comprising:
 a base;   a molded valve box of unitary construction pivotally mounted to the base, the valve box comprising:
 a valve chamber forming an inlet and an outlet and including a divider disposed therebetween; and 
 a valve plate comprising an inlet valve in flow communication with the inlet and an outlet valve in flow communication with the outlet; 
   a cylinder removeably mounted to the valve box; and   a piston assembly at least partially disposed within the cylinder, the piston assembly comprising:
 a pump shaft comprising a distal end proximate the valve box and a proximal end, the pump shaft comprising;
 a handle at the proximal end; 
 a molded piston of unitary construction at the distal end; and 
 a pair of opposing piston cups mounted to the piston. 
 
   
     
     
         2 . The manually operated pump of  claim 1 , wherein the valve chamber comprises:
 an inlet angled surface adapted to direct fluid through the inlet valve; and   an outlet angled surface adapted to direct fluid through the outlet.   
     
     
         3 . The manually operated pump of  claim 1 , wherein the valve plate further comprises a pair of shaped apertures adapted to accept a corresponding part of the inlet valve and the outlet valve, the part having a shape complementary to the shaped apertures, so as to secure the inlet valve and the outlet valve to the valve plate using no structural support beyond the shaped aperture. 
     
     
         4 . The manually operated pump of  claim 1 . wherein the inlet valve and the outlet valve are separate parts. 
     
     
         5 . The manually operated pump of  claim 1 , wherein the inlet valve and the outlet valve are formed in a single molded part of unitary construction. 
     
     
         6 . The manually operated pump of  claim 1 , wherein the cylinder is removeably mounted to the valve box with a threaded interface. 
     
     
         7 . The manually operated pump of  claim 1 , wherein the handle forms a T shape. 
     
     
         8 . The manually operated pump of  claim 1  further comprising a stopper cap disposed at a proximal end of the cylinder and adapted to prevent the pump shaft from being fully pulled out of the cylinder.  9 . The manually operated pump of  claim 8 , wherein the stopper cap comprises:
 an outer diameter greater than an outer diameter of the cylinder; and 
 a rim adapted to block a portion of a lumen formed by the cylinder. 
 
     
     
         10 . The manually operated pump of claim  9 , wherein the rim is adapted to engage at least one of the opposing piston cups to prevent the pump shaft from being fully pulled out of the cylinder. 
     
     
         11 . The manually operated pump of  claim 1  further comprising a filler cap forming an inlet disposed at the proximal end of the pump shaft and adapted to deliver a priming fluid into the cylinder to the piston assembly. 
     
     
         12 . The manually operated pump of  claim 11 , wherein the inlet comprises a frustoconical shape. 
     
     
         13 . The manually operated pump of  claim 11 , wherein the priming fluid is delivered to the pair of opposing piston cups through at least one weep hole formed in the piston. 
     
     
         14 . The manually operated pump of  claim 1 , wherein, at 1650 meters altitude, the pump is adapted to pump fluid from at least 6 meters below the pump to at least 6 meters above the pump. 
     
     
         15 . The manually operated pump of  claim 14 , wherein the pump is further adapted to pump fluid at an average flow rate of at least about 0.225 liters per second. 
     
     
         16 . A method of assembling a manually operated pump, the method comprising the steps of:
 providing a base;   pivotally mounting a molded valve box of unitary construction to the base;   attaching a valve plate to cover a valve chamber of the valve box;   inserting an inlet valve and an outlet valve into the valve plate;   mounting a molded piston of unitary construction to a distal end of a pump shaft;   mounting a pair of opposing piston cups to the molded piston;   disposing a cylinder about at least a portion of the pump shaft; and   removably mounting the cylinder to the valve box.   
     
     
         17 . The method of  claim 16 , wherein removeably mounting the cylinder to the valve box comprises threading the Cylinder onto the valve box a threaded interface. 
     
     
         18 . The method of  claim 16 , further comprising installing a stopper cap at a proximal end of the cylinder, the stopper cap being adapted to prevent the pump shaft from being fully pulled out of the cylinder. 
     
     
         19 . The method of  claim 16 , further comprising installing a filler cap forming an inlet at a proximal end of the pump shaft, the filler cap being adapted to deliver a priming fluid into the cylinder. 
     
     
         20 . The method of  claim 16 , further comprising installing a handle at a proximal end of the pump shaft.