US3874754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biohazard safety cabinet
Assignee: Kewaunee Scientific Corp
•
Filing: 1972-11-27
•
Granted: 1975-04-01
•
Expires: 1992-11-27
Abstract
Abstract A biological safety cabinet, including a hood structure defining a work chamber, at the bottom of which is a work surface, the cabinet being provided at its front wall with an access opening therein adjacent the work surface, and with means for creating an air flow through said chamber from top to bottom, which air may become contaminated by materials disposed in said chamber, air discharged from said chamber passing through a decontaminating filter disposed below the plane of said work surface, blower means arranged to withdraw decontaminated air passing through said filter and discharge the same in duct means operative to conduct such air to a chamber disposed above said work chamber, from which it is discharged into the latter at the top thereof. Means are also provided for readily effecting in a simple manner decontamination of the filter; for increasing the access opening in the work chamber to accommodate relatively large equipment; with control means, responsive to the size or closure of the access opening, for varying the operation of the blower; and indicating means for ascertaining operating conditions during normal or decontaminating functions. Means is also provided for effecting a relatively uniform distribution of air discharged into the top of said work chamber.
Inventors
- 👤 George T Saunders
- 👤 Joseph S Lattuca
- 👤 Dorman C Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:43
CPC Classifications
B; B01; B01L; B01L1/00; B01L1/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
443 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a hollow base structure, the upper portion of which is constructed to form a work surface, a hood structure extending above said work surface and adapted, in normal operation, to form a chamber enclosing said work surface, with the exception of an access opening adjacent one edge of said work surface, through which air may enter from exteriorly of the cabinet, the wall of said hood structure above said access opening being provided with a transparent window through which the interior thereof may be viewed, said base structure having openings therein adjacent said work surface for the flow of air from the hood interior into the base structure, an air distribution structure extending over the work surface, operative to discharge air in a downward direction toward said work surface, a vertically extending duct structure disposed adjacent the base and hood structures and operatively connecting the air distribution structure and said base structure and therewith forming an air path for the circulatory flow of air from said air distribution structure downwardly through said hood, through said openings in said base structure and said duct structure Back to said air distribution structure, a contaminate filter disposed in said air flow path and positioned in said base structure below the plane of said work surface, operative to intercept and filter the air flowing through said openings in the base structure, air moving means, having an air inlet and an air outlet, disposed in said air flow path intermediate the discharge side of said filter and said air distribution structure, with its air inlet disposed to receive air which has passed through the filter, and its air outlet disposed to effect movement of air through said air distribution structure, said air flow path having an air discharge vent therein, at the air discharge side of said air moving means, through which a portion of the air flow in said path may be discharged from the cabinet, said air moving means being operative to draw all air, entering said chamber from said air distribution structure and from exteriorly of the cabinet, through said openings and through said filter, with the contaminated volume of the cabinet thus being restricted to that portion of the base structure operatively disposed between the work surface and the filter, with the air moving means, the upper portion of the hood and the connecting duct structure all being subjected only to uncontaminated air, the exterior walls of said contaminate-subjected portion of the base structure being of airtight construction with respect to the exterior thereof.
Claim 2
Dependent Claim
443 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a hollow base structure, the upper portion of which is constructed to form a work surface, a hood structure extending above said work surface and adapted, in normal operation, to form a chamber enclosing said work surface, with the exception of an access opening adjacent one edge of said work surface, through which air may enter from exteriorly of the cabinet, the wall of said hood structure above said access opening being provided with a transparent window through which the interior thereof may be viewed, said base structure having openings therein adjacent said work surface for the flow of air from the hood interior into the base structure, an air distribution structure extending over the work surface, operative to discharge air in a downward direction toward said work surface, a vertically extending duct structure disposed adjacent the base and hood structures and operatively connecting the air distribution structure and said base structure and therewith forming an air path for the circulatory flow of air from said air distribution structure downwardly through said hood, through said openings in said base structure and said duct structure Back to said air distribution structure, a contaminate filter disposed in said air flow path and positioned in said base structure below the plane of said work surface, operative to intercept and filter the air flowing through said openings in the base structure, air moving means, having an air inlet and an air outlet, disposed in said air flow path intermediate the discharge side of said filter and said air distribution structure, with its air inlet disposed to receive air which has passed through the filter, and its air outlet disposed to effect movement of air through said air distribution structure, said air flow path having an air discharge vent therein, at the air discharge side of said air moving means, through which a portion of the air flow in said path may be discharged from the cabinet, said air moving means being operative to draw all air, entering said chamber from said air distribution structure and from exteriorly of the cabinet, through said openings and through said filter, with the contaminated volume of the cabinet thus being restricted to that portion of the base structure operatively disposed between the work surface and the filter, with the air moving means, the upper portion of the hood and the connecting duct structure all being subjected only to uncontaminated air, the exterior walls of said contaminate-subjected portion of the base structure being of airtight construction with respect to the exterior thereof.
Claim 3
Dependent Claim
58 words
A cabinet according to claim 1 wherein said transparent wall comprises a vertically extending sash member slidably supported by the associated hood structure and movable to vary the size of said access opening, and means cooperable with said sash, responsive to predetermined positioning of the latter, to effect a change in the operation of said air moving means.
Claim 4
Dependent Claim
78 words
A cabinet according to claim 1, wherein said air distribution structure comprises a pair of perforated plates disposed on spaced relation, between which extends a member of honey-comb configuration dividing the space between said plates into a plurality of passageways extending transversely to the plane of said plates, operative to direct air passing through said plates in substantially a common direction, with such a structure adapted to produce a predetermined pressure head at the air inlet side thereof.
Claim 5
Dependent Claim
51 words
A cabinet according to claim 1 wherein said filter is disposed beneath the work surface and extends substantially parallel thereto approximately coextensive with the cross sectional area of the base structure to provide a maximum filter area, and said air moving means is disposed in the base structure beneath the filter.
Claim 6
Dependent Claim
45 words
A cabinet according to claim 1, comprising in further combination respective releasable means engagable with said base structure at the top thereof and at the outlet of said air moving means for selectively sealing the interior of the base structure during decontamination of said filter.
Claim 7
Dependent Claim
65 words
A cabinet according to claim 5, wherein the sealing means for said outlet comprises a plate member and peripheral gasket means adapted to be mounted in sealing relation on said base structure at the air outlet therein, said duct structure having an access opening therein adjacent said air outlet for facilitating the mounting of such sealing means, and means for operatively closing said access opening.
Claim 8
Dependent Claim
113 words
A biological safety cabinet according to claim 1, wherein said air moving means includes a blower disposed in said base unit at the outlet side of said filter, said base unit having an air outlet opening therein communicating with the air outlet of said blower and the lower portion of said duct structure, and means for sealing said base unit during decontaminating operations, comprising a plate member adapted to extend over said work surface and secured in air-tight relation with respect to the peripheral top portions of said base unit, and a second plate member adapted to cover said air outlet in said base unit and secured to the latter in air-tight relation.
Claim 9
Dependent Claim
175 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a base structure, the top of which is constructed to provide a work surface, a hood structure operatively enclosing said work surface, and having an access opening therein adjacent the front edge of said work surface, means for circulating a flow of air through said work chamber downwardly from top to bottom thereof, including a blower, disposed in said base structure, having an air inlet and an air outlet, and duct means extending from the blower outlet to the top of said hood structure, the blower inlet communicating with the hood interior at the bottom thereof and adapted to withdraw all air entering the hood, decontaminating filter means disposed in the circulating air path for decontaminating all air flowing from the hood interior to the blower inlet, and means disposed adjacent said front edge of said work surface for discharging uncontaminated air generally horizontally inwardly therealong to improve inward air flow adjacent said access opening.
Claim 10
Dependent Claim
175 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a base structure, the top of which is constructed to provide a work surface, a hood structure operatively enclosing said work surface, and having an access opening therein adjacent the front edge of said work surface, means for circulating a flow of air through said work chamber downwardly from top to bottom thereof, including a blower, disposed in said base structure, having an air inlet and an air outlet, and duct means extending from the blower outlet to the top of said hood structure, the blower inlet communicating with the hood interior at the bottom thereof and adapted to withdraw all air entering the hood, decontaminating filter means disposed in the circulating air path for decontaminating all air flowing from the hood interior to the blower inlet, and means disposed adjacent said front edge of said work surface for discharging uncontaminated air generally horizontally inwardly therealong to improve inward air flow adjacent said access opening.
Claim 11
Dependent Claim
198 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a base structure, the top of which is constructed to provide a work surface, a hood structure operatively enclosing said work surface, means for circulating a flow of air through said work chamber downwardly from top to bottom thereof, including a blower, disposed in said base structure, having an air inlet and an air outlet, and duct means extending from the blower outlet to the top of said hood structure, the blower inlet communicating with the hood interior at the bottom thereof and adapted to withdraw all air entering the hood, decontaminating filter means disposed in said base unit for decontaminating all air flowing from the hood interior to the blower inlet, said base unit being adapted to be sealed during decontaminating operations, an air velocity indicator device having an input sensing tube operatively disposed in the decontaminated air flow path from said filter, and means for selectively connecting said input tube to the interior of said base unit when the latter is so sealed for decontaminating purposes, whereby said indicator device will indicate static fluid pressure therein.
Claim 12
Dependent Claim
198 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a base structure, the top of which is constructed to provide a work surface, a hood structure operatively enclosing said work surface, means for circulating a flow of air through said work chamber downwardly from top to bottom thereof, including a blower, disposed in said base structure, having an air inlet and an air outlet, and duct means extending from the blower outlet to the top of said hood structure, the blower inlet communicating with the hood interior at the bottom thereof and adapted to withdraw all air entering the hood, decontaminating filter means disposed in said base unit for decontaminating all air flowing from the hood interior to the blower inlet, said base unit being adapted to be sealed during decontaminating operations, an air velocity indicator device having an input sensing tube operatively disposed in the decontaminated air flow path from said filter, and means for selectively connecting said input tube to the interior of said base unit when the latter is so sealed for decontaminating purposes, whereby said indicator device will indicate static fluid pressure therein.
Claim 13
Dependent Claim
214 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a base structure, the top of which is constructed to provide a work surface, a hood structure operatively enclosing said work surface and constructed to provide an access opening adjacent the front edges of said work surface, means for circulating a flow of air through said work chamber from top to bottom thereof, including a blower, having an air inlet and an air outlet, disposed in said base unit, the latter having an air outlet opening therein communicating with the air outlet of said blower, and an air inlet opening in the top portion thereof through which all air entering the hood is adapted to be withdrawn, decontaminating filter means disposed in said base unit, intermediate the air inlet opening thereof and the air inlet of said blower, for decontaminating all air flowing therethrough, and means for sealing said base unit during decontaminating operations comprising a plate member adapted to extend over said work surface and secured in air-tight relation with respect to the peripheral top portion of said base unit, and a second plate member adapted to cover said air outlet in said base unit and secured to the latter in air-tight relation.
Claim 14
Dependent Claim
214 words
In a biological safety cabinet for preventing contamination externally of the cabinet from a contaminant disposed therein, the combination of a base structure, the top of which is constructed to provide a work surface, a hood structure operatively enclosing said work surface and constructed to provide an access opening adjacent the front edges of said work surface, means for circulating a flow of air through said work chamber from top to bottom thereof, including a blower, having an air inlet and an air outlet, disposed in said base unit, the latter having an air outlet opening therein communicating with the air outlet of said blower, and an air inlet opening in the top portion thereof through which all air entering the hood is adapted to be withdrawn, decontaminating filter means disposed in said base unit, intermediate the air inlet opening thereof and the air inlet of said blower, for decontaminating all air flowing therethrough, and means for sealing said base unit during decontaminating operations comprising a plate member adapted to extend over said work surface and secured in air-tight relation with respect to the peripheral top portion of said base unit, and a second plate member adapted to cover said air outlet in said base unit and secured to the latter in air-tight relation.
References Cited (Backward Citations)
US493321A
Cited
US3186327A
Cited
US3354495A
Cited
US3301163A
Cited
US3284148A
Cited
US3375773A
Cited
US3632180A
Cited
US3547505A
Cited
US3584927A
Cited
US3610716A
Cited
US3626837A
Cited
US3699871A
Cited
US3790347A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |