Pneumatically driven hydraulic pump

Abstract

A pneumatically driven hydraulic pump in accordance with the present invention is comprised of a cylindrical body, a front end cap, a rear end cap, a division wall, a piston, a control valve, a pneumatic valve, an air bladder and a pedal. The pneumatically piston and the air bladder also connected to the air source are used to quickly pump hydraulic fluid to an external hydraulic lifting device. Consequently, a heavy object can be lifted or lowered quickly.

What is claimed is:  
     
         1 . A pneumatically driven hydraulic pump comprising: 
 a cylindrical body ( 10 ) with a center, a front end, a rear end, a top, a bottom and two sides;    a pedal ( 11 ) with a first end and a second end pivotally mounted on the top of the cylindrical body ( 10 );    a division wall ( 12 ) with an upper portion, a central portion, a lower portion and a front and rear side mounted at the center of the cylindrical body ( 10 ), the division wall ( 12 ) having a hydraulic fluid discharge passage ( 15 ) define therein, an hydraulic fluid discharge opening ( 151 ) define at an end of the hydraulic fluid discharge passage ( 15 ), a check valve and a control valve ( 153 ) provided in the hydraulic fluid discharge passage ( 15 ), the control valve ( 153 ) extending out from the cylindrical body ( 10 ) to abut the first end of the pedal ( 11 ), and a hydraulic fluid return passage ( 154 ) in communication with the hydraulic fluid discharge passage ( 15 ) through the control valve ( 153 );    a connector mounted on one side of the cylindrical body ( 10 ) and having an hydraulic fluid discharge port ( 152 ) define in the connector communicating with the hydraulic fluid discharge passage ( 15 );    a hydraulic fluid reservoir ( 14 ) defined in the cylindrical body ( 10 ) at the front side of the division wall ( 12 ), the hydraulic fluid reservoir ( 14 ) communicating with the hydraulic fluid discharge passage ( 15 ) by the hydraulic fluid discharge opening ( 151 );    a piston chamber ( 13 ) defined in the cylindrical body ( 10 ) at the rear side of the division wall ( 12 ), the piston chamber ( 13 ) in communication with the hydraulic fluid discharge passage ( 15 );    a piston ( 17 ) longitudinally movably mounted in the piston chamber ( 13 ), the piston ( 17 ) having a piston rod ( 171 ) extending in a central channel of a piston seat beside the division wall ( 12 ), and a piston spring ( 172 ) provided outside the piston rod ( 171 ), wherein the central channel communicates with the inclined channel of the hydraulic fluid discharge passage ( 15 );    a rear-end cap ( 102 ) with an inside surface and an outside surface mounted on the rear end of the cylindrical body ( 10 ) to enclose the piston chamber ( 13 );    an air passage ( 16 ) uprightly defined in the rear-end cap ( 102 ) on the cylindrical body ( 10 ), the air passage ( 16 ) having an air inlet ( 161 ), an air discharge port ( 162 ) and an air vent ( 163 ) in turn defined on the outside surface of the rear-end cap ( 102 ) from bottom to top, and an air port ( 164 ) defined in the inside of the rear-end cap ( 102 ) and communicating between the air passage ( 16 ) and the piston chamber ( 13 );    a pneumatic valve ( 165 ) mounted in the air passage ( 16 ), the pneumatic valve ( 165 ) having a valve stem ( 166 ) with an upper end and a lower end slidably mounted in the air passage ( 16 ), the upper end of the valve stem ( 166 ) extending out from the air passage ( 16 ) and abutting the second end of the pedal ( 11 ), and a resilient member ( 167 ) mounted in the air passage ( 16 ) at the lower end of the valve stem ( 166 );    a front-end cap ( 101 ) with an inside surface and an outside surface mounted on the front end of the cylindrical body ( 10 ) to enclose the hydraulic fluid reservoir ( 14 ); and    an air bladder ( 18 ) mounted on the inside surface of the front-end cap ( 101 ) in the hydraulic fluid reservoir ( 14 ) and in communication with the air discharge port ( 162 ) through a tube ( 19 ), hydraulic fluid ( 141 ) received in the hydraulic fluid reservoir ( 14 ) but outside the air bladder ( 18 ).    
     
     
         2 . The pneumatic hydraulic pump as claimed in  claim 1 , wherein the tube ( 19 ) connects to the air bladder ( 18 ) through a joint on the front-end cap ( 101 ).