US3822699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instrument for measuring maximum expiratory flow rate
Assignee: Individual
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Filing: 1973-02-28
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Granted: 1974-07-09
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Expires: 1993-02-28
Abstract
Abstract An instrument for measuring maximum expiratory flow rate having a vertically-disposed cylinder with a plurality of equal sized orifices distributed along its length, a floating piston disposed in the cylinder having a guide rod passing through a closure on the top of the cylinder, a self-actuating brake means mounted on the guide rod above the piston and actuatable against the side of the cylinder, a holdback clip mounted on the cylinder closure and operatively engaging the guide rod to prevent the guide rod from moving downwardly once the piston has moved upwardly in the cylinder and a suitable, flexible air tube having a mouthpiece at one end and connected in open communication with the bottom of the cylinder at its other end. The instrument can also be provided with a check valve at the lower end of the cylinder to prevent backflow of air through the air tube and adjustable port means adjacent the base of the cylinder to adjust the range of the instrument.
Inventors
- 👤 J Cleary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:47
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/08; A61B5/083; A61B5/087; A61B5/0871
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
143 words
Apparatus for measuring a patient''s maximum expiratory flow rate, comprising; a cylinder having a central bore of equal diameter throughout its length, one end closed and the other end provided with an air inlet means to form a closed chamber except for said air inlet, air tube means having one end in open communication with said air inlet and the other end provided with a sanitary mouth piece, restricted air outlet means in said chamber to permit regulatEd amounts of air to escape from said chamber, piston means slidably mounted in said cylinder and moveable toward said closed end in response to the pressure of air passing through said air inlet and brake means carried by said piston means selectively engaging said bore to decelerate and stop the upward movement of said piston means as the air pressure moving said piston means decreases.
Claim 2
Dependent Claim
143 words
Apparatus for measuring a patient''s maximum expiratory flow rate, comprising; a cylinder having a central bore of equal diameter throughout its length, one end closed and the other end provided with an air inlet means to form a closed chamber except for said air inlet, air tube means having one end in open communication with said air inlet and the other end provided with a sanitary mouth piece, restricted air outlet means in said chamber to permit regulatEd amounts of air to escape from said chamber, piston means slidably mounted in said cylinder and moveable toward said closed end in response to the pressure of air passing through said air inlet and brake means carried by said piston means selectively engaging said bore to decelerate and stop the upward movement of said piston means as the air pressure moving said piston means decreases.
Claim 3
Dependent Claim
32 words
Apparatus in accordance with claim 1 wherein the air outlet means is a plurality of equal-diameter orifices passing through the wall of the cylinder and spaced along the length of said cylinder.
Claim 4
Dependent Claim
32 words
Apparatus in accordance with claim 1 wherein guide rod means has one end thereof attached to the piston means and the body thereof slidably passing through the closed end of the cylinder.
Claim 5
Dependent Claim
63 words
Apparatus in accordance with claim 3 wherein holdback means is mounted in operative relation with the guide rod and adjacent the closed end of the cylinder to releasably hold said guide rod and prevent said guide rod and piston from sliding toward the air inlet while permitting free movement of said guide rod and said piston toward said closed end of said cylinder.
Claim 6
Dependent Claim
55 words
Apparatus in accordance with claim 1 wherein the brake means includes a flat flexible element having a maximum dimension such as to frictionally contact the wall of the cylinder when fully extended in an unflexed condition and to be free of said wall of said cylinder when flexed and means for flexing said flexible element.
Claim 7
Dependent Claim
17 words
Apparatus in accordance with claim 5 wherein the means for flexing the flexible element is a weight.
Claim 8
Dependent Claim
56 words
Apparatus in accordance with claim 6 wherein guide rod means has one end thereof attached to the piston and the body thereof slidably passing through the closed end of the cylinder and the flexible element and the weight are freely slidably mounted on said guide rod between said piston and said closed end of said cylinder.
Claim 9
Dependent Claim
24 words
Apparatus in accordance with claim 6 wherein the mass of the weight is greater than the mass of the guide rod plus the piston.
Claim 10
Dependent Claim
23 words
Apparatus in accordance with claim 1 wherein the cylinder is transparent and calibrated to indicate the position of the piston within said cylinder.
Claim 11
Dependent Claim
35 words
Apparatus in accordance with claim 1 wherein the holdback means is a spring type clip having an aperture therethrough through which the guide rod passes and is bent toward the closed end of the cylinder.
Claim 12
Dependent Claim
28 words
Apparatus in accordance with claim 1 wherein the air inlet includes a base and said base has an air passage therein connecting said cylinder and the air tube.
Claim 13
Dependent Claim
43 words
Apparatus in accordance with claim 11 wherein the air passage in the base has a check valve formed therein to prevent passage of air from the cylinder to the air tube while permitting passage of air from said air tube to said cylinder.
Claim 14
Dependent Claim
34 words
Apparatus in accordance with claim 12 wherein the check valve comprises a valve seat formed in the base adjacent the open end of the cylinder and a free floating ball disposed above said seat.
Claim 15
Dependent Claim
30 words
Apparatus in accordance with claim 1 wherein the cylinder has operatively associated therewith means for changing the amount of air which can pass out of said cylinder below the piston.
Claim 16
Dependent Claim
68 words
Apparatus in accordance with claim 14 wherein the air inlet includes a base and said base has an air passage therein connecting said cylinder and the air tube, the cylinder is rotatably mounted in said base and the means for changing the amount of air which can pass out of said cylinder is an orifice through the wall of said cylinder registerable with an orifice through said base.
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) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |