Pump particularly useful in respirator apparatus and exhalation valve assembly therefor
First Claim
1. A reciprocating pump particularly useful in ventilator apparatus, comprising:
- a pump housing having an inlet at one end, an outlet at another end, and a cylinder between said inlet and outlet;
a piston reciprocatable axially within said cylinder and dividing its interior into an inlet chamber communicating with said inlet, and an outlet chamber communicating with said outlet;
a fixed wall within said inlet chamber and having a passageway therethrough communicating with said inlet;
a drive housing fixed to said wall and including a motor having a rotor rotatable by the energization of said motor;
a nut rotatable within said drive housing and fixed to said rotor to rotate therewith;
and a screw threadedly coupled at one end to said nut and fixed at its opposite end to said piston;
said piston being supported by a single rotatable bearing between said nut and the drive housing and a seal between said piston and the cylinder.
1 Assignment
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Accused Products
Abstract
A reciprocating pump particularly useful in ventilator apparatus includes a piston reciprocatable axially within a cylinder and dividing its interior into an inlet chamber and an outlet chamber, a wall fixed within the inlet chamber, and a drive housing fixed to the wall. The drive housing includes a motor, a rotor rotatable by the motor, a nut rotatable within the drive housing, and a screw threadedly coupled at one end to the nut and fixed at its opposite end to the piston. The piston is substantially unrestrained for axial and rotary movement such that forward and reverse rotation of the nut by the motor reciprocates the screw and the piston axially of the cylinder, and also permits the screw and the piston to rotate with respect to the cylinder to thereby even out wear between the piston and cylinder.
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Citations
10 Claims
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1. A reciprocating pump particularly useful in ventilator apparatus, comprising:
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a pump housing having an inlet at one end, an outlet at another end, and a cylinder between said inlet and outlet; a piston reciprocatable axially within said cylinder and dividing its interior into an inlet chamber communicating with said inlet, and an outlet chamber communicating with said outlet; a fixed wall within said inlet chamber and having a passageway therethrough communicating with said inlet; a drive housing fixed to said wall and including a motor having a rotor rotatable by the energization of said motor; a nut rotatable within said drive housing and fixed to said rotor to rotate therewith; and a screw threadedly coupled at one end to said nut and fixed at its opposite end to said piston; said piston being supported by a single rotatable bearing between said nut and the drive housing and a seal between said piston and the cylinder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification