US 5,606,131 A · Piston manometer with spring constant dependent upon position

Abstract

A manometer for use in a patient's breathing circuit, comprising a housing forming a bore and a slider movably mounted within the bore. The slider is movable between an at-rest position, an expanded pressure range, and a contracted pressure range. A spring is connected to the slider for urging the slider toward the at-rest position, while allowing movement of the slider in the two ranges due the pressure in the breathing circuit. The housing is connectable to the breathing circuit such that the gas pressure moves the slider from the at rest position and into at least the expanded pressure range. At relatively low pressures, the slider is moved into the expanded pressure range and at higher pressures, the slider is moved into the contracted pressure range against the force of the spring. The spring is formed by a relatively short tension spring and a relatively long tension spring.

Claims8

Dependent claims

Apparatus for providing an indication of the magnitude of a device air pressure present in a device relative to a reference air pressure, said apparatus comprising

(a) a housing forming an internal bore, said bore having first and second end portions;
(b) said first end portion being connectable to said device such that said device air pressure is present in said first end portion, and said second end portion being exposed to said reference air pressure;
(c) a slider movably mounted in said bore and exposed to said device air pressure, said slider being at an at-rest position when said device air pressure is substantially equal to said reference air pressure;
and
(d) first and second tension springs connected between said slider and said housing, each of said springs having one end thereof connected to said slider and another end thereof connected to said housing, said slider being movable in two ranges of movement, said first range being adjacent said at-rest position and said second range being displaced from said at-rest position, only said first spring restraining movement of said piston in said first range and both said first and second springs restraining movement of said piston in said second range.

2 more elements

Dependencies are inferred from the claim text.

Piston manometer with spring constant dependent upon position

Life of this patent

Piston manometer with spring constant dependent upon position

Life of this patent

Abstract

Claims8