Patent ID: 6234774
Filing Date: 2001-05-22
Classification: F04B

Abstract:
A double-acting pump, especially for use with a rubber dinghy, comprising a main cylindrical body (11) having an internal volume (12), a piston (13) which slides in said internal volume, and end chambers (60, 61) closed by flat bodies, said flat bodies comprising heads (24), each head including a seal-valve (31, 26) and an internal face with holes that communicate with the atmosphere, such that movement of the piston in one direction automatically causes opening of the valve (31) in the head from which the piston is moving away, and closure of the valve (31) in the head which the piston is approaching, which produces suction in the chamber (60, 61) created by departure of the piston and simultaneous compression in the chamber (60, 61) which the piston is approaching, suction and compression being reversed when the piston changes direction, each said valve comprising an elastic diaphragm which adheres to the internal face of the head in an area in which the holes (30) in said head communicate with the atmosphere, the suction distorting the valve (31) and pressing it away from the internal face of the head, causing it to free the holes (30), and open the valve for entry of air, and compression causing the valve to adhere against the internal face of the head to keep said valve closed.