Collapsible Bilge Pump

Abstract

A collapsible bilge pump includes outer and inner cylinders telescopable between retracted and extended posiions. A piston is movable up and down within the inner cylinder. Check valves in the bottom of the outer cylinder and in the piston permit the pump to take in water at the bottom end of the pump and discharge it from the top end. The collapsible pump is easily stowed, and its short stroke, limited to the length of the inner cylinder, is substantaially easier to perform.

1 . A collapsible bilge pump including:
 a hollow outer cylinder with top and bottom ends, a hollow inner cylinder with top and bottom ends, and a piston axially movable up and down within said inner cylinder;   said cylinders axially movable relative to each other between retracted and extended positions, the top end of said outer cylinder and the bottom end of said inner cylinder adapted for mutual sealing engagement in said extended positions;   said outer cylinder including a fluid inlet check valve on the bottom end thereof to permit fluid intake into said outer cylinder and to prevent fluid backflow from said outer cylinder;   said piston including a lift check valve on said bottom end thereof for fluid transfer from said outer cylinder into said inner cylinder;   whereby, upward movement of said piston closes said lift check valve to draw fluid through said inlet check valve into said outer cylinder, and downward movement of said piston closes said inlet check valve and opens said lift check valve to admit fluid from said outer cylinder into said inner cylinder for discharge from said top end thereof.   
     
     
         2 . A collapsible bilge pump as defined in  claim 1  wherein said engagement of said inner and outer cylinders is by circumferential frictional contact. 
     
     
         3 . A collapsible bilge pump as defined in  claim 1  wherein said inner and outer cylinders are adapted for mating engagement in said extended condition of said pump. 
     
     
         4 . A collapsible bilge pump as defined in  claim 3  wherein said mating engagement of said inner and outer cylinders is threaded. 
     
     
         5 . A collapsible bilge pump as defined in  claim 1 , further including a foam flotation collar surrounding said outer cylinder. 
     
     
         6 . A collapsible bilge pump including:
 an outer cylinder with top and bottom ends, an inner cylinder with top and bottom ends, and a piston rod axially movable in said inner cylinder in reciprocal strokes defined by the height of said inner cylinder;   said cylinders axially movable relative to each other between retracted and extended positions, the top end of said outer cylinder and the bottom end of said inner cylinder adapted for mutual sealing engagement in said extended positions;   said outer cylinder including a fluid inlet check valve on the bottom end thereof to permit fluid intake into said outer cylinder and to prevent fluid backflow from said outer cylinder;   said inner cylinder being open at the bottom end thereof, and including a discharge nozzle on the top end thereof;   said piston rod including a piston within said inner cylinder, and a handle extending from the top end of said inner cylinder;   said piston including a lift check valve to permit fluid transfer therethrough from said outer cylinder into said inner cylinder, and to prevent fluid backflow from said inner cylinder;   whereby, upward movement of said piston closes said lift check valve to draw fluid through said inlet check valve into said outer cylinder, and downward movement of said piston closes said inlet check valve and opens said lift check valve to admit fluid from said outer cylinder into said inner cylinder for discharge therefrom.   
     
     
         7 . A collapsible bilge pump as defined in  claim 6  wherein said engagement of said inner and outer cylinders is by circumferential frictional contact. 
     
     
         8 . A collapsible bilge pump as defined in  claim 6  wherein said inner and outer cylinders are adapted for mating engagement in said extended condition of said pump. 
     
     
         9 . A collapsible bilge pump as defined in  claim 8  wherein said mating engagement of said inner and outer cylinders is threaded. 
     
     
         10 . A collapsible bilge pump as defined in  claim 6 , further including a foam flotation collar surrounding said outer cylinder.