US 4,493,614 A · Pump for a portable ventilator

Abstract

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.

Claims24

Dependent claims

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.

2 more elements

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.

4 more elements

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.

3 more elements

A pump primarily intended for use in a ventilator, said pump comprising:

a substantially cylindrical member extending along an axis and having at least one end wall, said cylindrical member having fluid inlet and outlet ports,
a piston member and means for reciprocally moving said piston member along said axis toward and away from said end wall, said piston member having a first side extending about said axis with an external diameter substantially equal to the internal diameter of the cylindrical member, said piston member further having a second side spaced from the first side along said axis and an aperture extending through said piston member between said first and second sides,
said moving means including a shaft, means for rotatably mounting said shaft with at least a portion thereof at a fixed location along said axis, said portion extending substantially longitudinally within said cylindrical member and extending through the aperture of said piston member, means for rotating said shaft, and means attached between said piston member and said shaft portion for moving said piston member relative to and along said shaft portion within said cylindrical member in response to rotation of said shaft, said means for rotating said shaft including an electric motor, said electric motor having a power source comprising a primary electric circuit, a secondary electric circuit directly connected to said motor, and a transformer whereby electrical power from said primary circuit is transferred to said secondary circuit by magnetic induction so that said electric motor is not directly connected to said primary electric circuit and wherein said transformer is substantially toroid-shaped and said pump includes means for mounting said transformer substantially about said shaft, and
means for substantially preventing any flow of fluid within said cylindrical member through said aperture between the first and second sides of said piston member as said piston member is moved within the cylindrical member whereby said cylindrical member and piston member form a variable volume, working chamber between the first side of the piston member and the end wall of the cylindrical member wherein fluid enters and exits said working chamber through said ports in response to the reciprocal movement of said piston member within said cylindrical member.

1 more element

A pump primarily intended for use in a ventilator, said pump comprising:

a substantially cylindrical member extending along an axis and having at least one end wall, said cylindrical member having fluid inlet and outlet ports,
a piston member and means for reciprocally moving said piston member along said axis toward and away from said end wall, said piston member having a first side extending about said axis with an external diameter substantially equal to the internal diameter of the cylindrical member, said piston member further having a second side spaced from the first side along said axis and an aperature extending through said piston member between said first and second sides,
said moving means including a shaft, means for rotatably mounting said shaft with at least a portion thereof at a fixed location along said axis, said portion extending substantially longitudinally within said cylindrical member and extending through the aperature of said piston member, means for rotating said shaft, and means attached between said piston member and said shaft portion for moving said piston member relative to and along said shaft portion within said cylindrical member in response to rotation of said shaft, said shaft portion having a threaded exterior surface and said means attached between said piston member and said shaft portion including a ball nut and means for mounting said ball nut on said shaft portion whereby said ball nut and piston member move relative to and along said shaft portion within said cylindrical member in response to rotation of said shaft, and
means for substantially preventing any flow of fluid within said cylindrical member through said aperature between the first and second sides of said piston member as said piston member is moved within the cylindrical member whereby said cylindrical member and piston member form a variable volume, working chamber between the first side of the piston member and the end wall of the cylindrical member wherein fluid enters and exits said working chamber through said ports in response to the reciprocal movement of said piston member within said cylindrical member and wherein said flow preventing means includes a second nut having a threaded interior surface conforming substantially to the threaded exterior surface of said shaft portion and forming a substantially fluid-tight seal therewith, and means for mounting said second nut to said ball nut for movement integrally therewith as a unit in response to rotation of said shaft.

1 more element

Dependencies are inferred from the claim text.

Pump for a portable ventilator

Life of this patent

Pump for a portable ventilator

Life of this patent

Abstract

Claims24