US3862628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Peak flow meters
Assignee: Ferraris Development and Engineering Co Ltd
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Filing: 1972-05-02
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Granted: 1975-01-28
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Expires: 1992-05-02
Abstract
Abstract A peak flow meter for determining the maximum flow of air exhaled by a person. The meter comprises a piston or a vane which is housed within a casing so as to be moved within the casing against the action of a spring by air blown into the casing. The piston or vane moves alongside a uniform width slot in the casing so as to expose a portion of the slot to the space within the casing into which air is blown, the slot portion so exposed increasing in length with movement of the vane or piston. The position relative to the slot at which the piston or vane comes to rest is an indication of the rate of flow of air blown into the casing. The improvement comprises providing a gap between the piston or vane and the casing wall, the cross-sectional area of the gap varying for different positions of the piston or vane within the casing so that the sensitivity of the meter varies correspondingly.
Inventors
- 👤 Garnet Montague Evele Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:46
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/28; A; A61; A61B; A61B5/00; A61B5/08; A61B5/087; A61B5/0871; G01F1/22
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
245 words
A peak flow meter for determining the maximum flow of air which a person can produce when exhaling air, comprising a casing having a mouthpiece and defining a chamber, a member having an inoperative position and movable relative to the casing within the chamber and carrying an indicator movable relative to scale markings on the casing, resilient means acting upon the movable member to oppose movement of the movable member away from the mouthpiece and retain it in contact with abutment means, and a slotted area extending through the casing into the chamber arranged to receive the movable indicator, the width of the slot being uniform, the arrangement being such that air blown into the mouthpiece by a person acts upon the movable member to urge it away from the mouthpiece against the action of the resilient means, such movement of the movable member away from the mouthpiece increasing the length of the slot portion which opens into that part of the chamber between the mouthpiece and the movable member and through which air blown into the chamber can escape, in which the improvement comprises providing a frustoconical chamber wall surrounding the movable member, said frustoconical wall extending beyond said abutment means and in the direction of movement of the movable member, said indicator being movable into an operative position by air blown into the mouthpiece with the degree of movement of the indicator partly dependent upon the direction in which the frusto-conical wall extends.
Claim 2
Dependent Claim
245 words
A peak flow meter for determining the maximum flow of air which a person can produce when exhaling air, comprising a casing having a mouthpiece and defining a chamber, a member having an inoperative position and movable relative to the casing within the chamber and carrying an indicator movable relative to scale markings on the casing, resilient means acting upon the movable member to oppose movement of the movable member away from the mouthpiece and retain it in contact with abutment means, and a slotted area extending through the casing into the chamber arranged to receive the movable indicator, the width of the slot being uniform, the arrangement being such that air blown into the mouthpiece by a person acts upon the movable member to urge it away from the mouthpiece against the action of the resilient means, such movement of the movable member away from the mouthpiece increasing the length of the slot portion which opens into that part of the chamber between the mouthpiece and the movable member and through which air blown into the chamber can escape, in which the improvement comprises providing a frustoconical chamber wall surrounding the movable member, said frustoconical wall extending beyond said abutment means and in the direction of movement of the movable member, said indicator being movable into an operative position by air blown into the mouthpiece with the degree of movement of the indicator partly dependent upon the direction in which the frusto-conical wall extends.
Claim 3
Dependent Claim
20 words
A peak flow meter as claimed in claim 1, wherein the frusto-conical wall diverges in its extent toward said mouthpiece.
Claim 4
Dependent Claim
45 words
A peak flow meter as claimed in claim 1, wherein said casing includes a sleeve member, wherein said abutment means includes an abutment at the terminus of said sleeve member, and wherein said frusto-conical wall is arranged to encompass a portion of the sleeve member.
Claim 5
Dependent Claim
21 words
A peak flow meter as claimed in claim 1, wherein said frusto-conical wall diverges in its extent away from the mouthpiece.
Claim 6
Dependent Claim
244 words
A peak flow meter for determining the maximum flow of air which a person can produce when exhaling air, comprising a casing having a mouthpiece and bottom, side and top walls defining a chamber having an inner wall, a member movable relative to the casing within the chamber and carrying an indicator movable relative to scale markings on the top wall of the casing, resilient means acting upon the movable member to oppose movement of the movable member away from the mouthpiece, and a slot extending through the bottom wall of the casing and into the chamber, the width of the slot being uniform, the arrangement being such that air blown inTo the mouthpiece by a person acts upon the movable member to urge it away from the mouthpiece against the action of the resilient means, such movement of the movable member away from the mouthpiece increasing the length of the slot portion which opens into that part of the chamber between the mouthpiece and the movable member and through which air blown into the chamber can escape, wherein the casing is cylindrical, the movable member is a vane which extends radially from an axle mounted within the cylindrical casing for rotation about the axis of the casing, the slot follows an arcuate path, and said vane and the inner wall define a gap which increases in width as said vane moves further away from the mouthpiece against the action of the resilient means.
Claim 7
Dependent Claim
244 words
A peak flow meter for determining the maximum flow of air which a person can produce when exhaling air, comprising a casing having a mouthpiece and bottom, side and top walls defining a chamber having an inner wall, a member movable relative to the casing within the chamber and carrying an indicator movable relative to scale markings on the top wall of the casing, resilient means acting upon the movable member to oppose movement of the movable member away from the mouthpiece, and a slot extending through the bottom wall of the casing and into the chamber, the width of the slot being uniform, the arrangement being such that air blown inTo the mouthpiece by a person acts upon the movable member to urge it away from the mouthpiece against the action of the resilient means, such movement of the movable member away from the mouthpiece increasing the length of the slot portion which opens into that part of the chamber between the mouthpiece and the movable member and through which air blown into the chamber can escape, wherein the casing is cylindrical, the movable member is a vane which extends radially from an axle mounted within the cylindrical casing for rotation about the axis of the casing, the slot follows an arcuate path, and said vane and the inner wall define a gap which increases in width as said vane moves further away from the mouthpiece against the action of the resilient means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |