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A pump primarily intended for use in a portable ventilator. The pump includes a piston-cylinder arrangement in which the piston is reciprocally moved within the cylinder by rotating a shaft. The shaft is threaded and mounted for rotation within the cylinder at a fixed location along the axis of the

A pump primarily intended for use in a portable ventilator. The pump includes a piston-cylinder arrangement in which the piston is reciprocally moved within the cylinder by rotating a shaft. The shaft is threaded and mounted for rotation within the cylinder at a fixed location along the axis of the cylinder. The piston has an aperture through its center and the shaft extends substantially between the end walls of the cylinder and through the center of the piston. The piston is held against rotation relative to the shaft and cylinder by a collapsible hinge and is attached to the shaft by an arrangement including a ball nut and sealing nut. The piston forms a variable volume, working chamber with one end of the cylinder and in operation, the shaft is selectively rotated to move the piston toward and away from the end wall. This positioning of the shaft within the cylinder reduces the overall size of the pump and specifically adapts it for use in a portable ventilator in which size limitations are critical.

대표청구항 ▼

A pump comprising: a cylinder capable of containing a fluid and having at least one end wall, said cylinder having fluid inlet and outlet ports; a piston disposed substantially within said cylinder for substantially, longitudinally reciprocating within said cylinder, the external diameter of said pi

A pump comprising: a cylinder capable of containing a fluid and having at least one end wall, said cylinder having fluid inlet and outlet ports; a piston disposed substantially within said cylinder for substantially, longitudinally reciprocating within said cylinder, the external diameter of said piston being substantially equal to the internal diameter of said cylinder, and said piston provided with an aperture substantially, longitudinally therethrough; a rotatable shaft extending substantially longitudinally through said cylinder and through the aperture in said piston; means disposed substantially within said cylinder for reciprocating said piston within said cylinder in response to the rotation of said shaft, said means including means for substantially preventing the rotation of said piston during its reciprocation within said cylinder wherein said rotation preventing means includes a collapsible hinge, and, means for substantially preventing the flow of any fluid with in said cylinder from one longitudinal side of said piston to the other longitudinal side of said piston when said piston reciprocates within said cylinder. A pump comprising: a cylinder capable of containing a fluid and having at least one end wall, said cylinder having fluid inlet and outlet ports; a piston disposed substantially within said cylinder for substantially, longitudinally reciprocating within said cylinder, the external diameter of said piston being substantially equal to the internal diameter of said cylinder, and said piston provided with an aperture substantially, longitudinally therethrough; a rotatable shaft extending substantially longitudinally through said cylinder and through the aperture in said piston; means disposed substantially within said cylinder for reciprocating said piston within said cylinder in response to the rotation of said shaft; means for substantially preventing the flow of any fluid within said cylinder from one longitudinal side of said piston when said piston reciprocates within said cylinder; and, said pump further includes an electric motor for selectively rotating said shaft, a primary electric circuit, a secondary electric circuit operatively connected to said electric motor, and a transformer for transferring energy from said primary circuit to said secondary circuit by magnetic induction, said transformer disposed adjacent to an end wall of said cylinder wherein said transformer is fashioned substantially in the shape of a toroid and wherein siad transformer substantially surrounds said shaft. A pump comprising: a cylinder capable of containing a fluid and having at least one end wall, said cylinder having fluid inlet and outlet ports; a piston disposed substantially within said cylinder for substantially, longitudinally reciprocating within said cylinder, the external diameter of said piston being substantially equal to the internal diameter of said cylinder, and said pion provided with an aperture substantially, longitudinally therethrough; a rotatable shaft extending substantially longitudinally through said cylinder and through the aperture in said piston, said rotatable shaft being provided with a threaded exterior surface; means disposed substantially within said cylinder for reciprocating said piston within said cylinder in response to the rotation of said shaft, said reciprocating means including a ball nut coupled to said piston and mounted on said shaft such that the ball nut translates along said shaft in response to the rotation of said shaft; and means for substantially preventing the flow of any fluid within said cylinder from one longitudinal side of said piston to the other longitudinal side of said piston when said piston reciprocates within said cylinder, said flow preventing means including a second nut mounted on said shaft and having a threaded interior surface conforming substantially identically with the shaft threaded surface such that fluid flow along said shaft, between the second nut and said shaft, is substantially prevented and means for mounting said second nut to said ball nut wherein the second nut correspondingly translates integrally with the ball nut as a unit along said shaft in response to the rotation of said shaft.