Ventilated animal caging system with cage racks and filter covers including valves operable by rack

• US 5,044,316 A
• Filed: 03/28/1990
• Issued: 09/03/1991
• Est. Priority Date: 03/28/1990
• Status: Expired due to Term

• Current Assignee: Thoren Caging Systems, Inc.
• Original Assignee: Thoren Caging Systems, Inc.
• Inventors: Thomas, William R.
• Primary Examiner(s): WEISS, JOHN
• Application Number:
  US07/500,068
• Time in Patent Office: 524 Days
• Field of Search: 119/15, 119/17
• US Class Current: 119/419
• CPC Class Codes: A01K 1/031 Cages for laboratory animals; Cages for measuring metabolism of animals

Abstract

A ventilated caging system of the type having ducted shelves with lower planar surfaces for box-like animal enclosures, the shelves having duct openings for powered supply and exhaust of air to the animal cages, has valved filter covers operable to isolate the animal enclosure from ingress and egress of airborne particles. The filter cover has a frame sealingly engaging a perimeter of the cage, the frame carrying a filter membrane with at least one opening. A support web integral with the frame extends inwardly of the perimeter within the frame to support a valve. A movable valve body in the form of a leaf spring is mounted on the support web, the valve body including a blocking portion resiliently urged to block the opening in the filter membrane, and a contact portion protruding through the opening by an opening displacement of the valve body, the blocking portion being displaced by the contact portion when the cage is fitted in the ventilating rack, whereupon the valve is opened, and the blocking portion being resiliently released to cover the opening when the cage is removed from contact with the ventilating rack, whereupon the valve is closed.

Claims

1. A cover for an animal cage of the type having an enclosure body opening at a perimeter residing in a plane, the cage being removably fittable in a ventilating rack with the perimeter disposed against mean associated with the rack providing powered airflow through the animal cage, the cover comprising:

a frame dimensioned to sealingly engage the perimeter of an area of the cage, the frame having a minimal thickness in the perimeter of the cage, whereby the cage can be fitted into the ventilating rack with the frame in place on the perimeter;

a support web attached to the frame, the support web extending inwardly of the perimeter within the frame;

a filter membrane sealed to the frame, the filter membrane

blocking passage of airborne particles, the filter membrane having an opening adjacent the support web; and

,

a movable valve body mounted on the support web, the valve body including a blocking portion resiliently urged to block said opening in the filter membrane, and a contact portion protruding through the opening by an opening displacement of the valve body, the blocking portion being displaced by the contact portion when the cage is fitted in the ventilating rack, whereupon the valve is opened, and the blocking portion being resiliently released to cover the opening when the cage is removed from contact with the ventilating rack, whereupon the valve is closed.

2. The cage cover according to claim 1, wherein the frame includes a plurality of webs disposed across the perimeter of the cage, said support web being attached to at least one of the frame and the plurality of webs.

3. The cage cover according to claim 2, wherein the plurality of webs include at least one web substantially crossing the perimeter, and wherein the support web extends between the frame and said at least one web.

4. The cage cover according to claim 1, wherein the filter membrane is bonded to the frame along substantially the entire said perimeter on a side directed outwardly of the cage toward the ventilating rack.

5. The cage cover according to claim 2, wherein the filter membrane is bonded to the frame, the support web and the plurality of webs

6. The cage cover according to claim 2, wherein the valve body includes a spring strip attached to the support web at a space from the opening in the filter membrane, the spring strip being normally disposed coplanar with the frame, the contact portion being attached to the spring strip at a space from an attachment thereof to the support web, the contact portion protruding through the opening in the filter membrane.

7. The cage cover according to claim 6, wherein the support web laterally encloses the spring strip, the support web having an extension inwardly of the cage that is less than the opening displacement of the valve body.

8. The cage cover according to claim 7, wherein the filter membrane is bonded to the frame and to the support web along all surfaces thereof directed outwardly of the cage.

9. The cage cover according to claim 8, wherein the frame is plastic resin and the filter membrane is spunbonded polyester resin and is heat bonded to the frame.

10. The cage cover according to claim 9, wherein the frame, support web and plurality of webs are integrally molded plastic resin and wherein the plurality of webs include webs crossing centrally over the perimeter of the enclosure body, the support web extending from at least one of the central webs to the frame.

11. A valved cover for an animal cage having a box-like airtight body opening at a perimeter, the perimeter to be placed in proximity with a duct means for establishing air communication with the animal cage, the valved cover comprising:

a frame engageable with the perimeter of the animal cage;

a valve body movably disposed over the opening, the valve body including a strip attached to the frame at a space from the opening, the strip at rest residing across the opening to block airflow through the opening; and

,

a contact member dimensioned to protrude from the valve cover, the contact member being operative when depressed perpendicular to a plane defined by said perimeter to press the strip back from the opening, the contact member being disposed between the strip and an opening in a member attached to the frame.

12. The valved cover according to claim 11, wherein the contact member is attached to the strip.

13. The valved cover according to claim 11, wherein the contact member is captive between the strip and the opening in said member by means of the opening being tapered to engage the contact member.

14. The valved cover according to claim 13, wherein the contact member is a ball member.

15. The valved cover according to claim 11, wherein the valved cover has an air passing filter material disposed across areas of the cover adjacent the opening.

16. The valved cover according to claim 15, wherein the contact member is a ball member and is captured between the strip and a tapering opening in said member attached to the frame.

17. The valved cover according to claim 16, wherein the ball is disposed between the opening and a point of attachment between the strip and the cover.

18. A ventilated caging system, comprising:

at least one ducted body with a planar surface having duct openings for supply and exhaust of air;

powered ventilating means supplying air and exhausting air

a plurality of animal cages, each of the cages having substantially airtight walls defining five sides of an animal enclosure and having an open planar side to be fitted against said planar surface of the ducted body;

support means operable to urge the cages into a position wherein the open planar side is fitted against the planar surface of the ducted body;

a valved filter cover operable to isolate the animal enclosure from ingress and egress of airborne particles, the filter cover including a frame dimensioned to sealingly engage a perimeter of the open planar side of the cage;

a support web attached to the frame, the support web extending inwardly of the perimeter within the frame;

a filter membrane sealed to the frame, the filter membrane blocking passage of airborne particles, the filter membrane having an opening adjacent the support web; and

,

a movable valve body mounted on the support web, the valve body including a blocking portion resiliently urged to block said opening in the filter membrane, and a contact portion protruding through the opening by an opening displacement of the valve body, the blocking portion being displaced by the contact portion when the cage is fitted in the ventilating rack, whereupon the valve is opened, and the blocking portion being resiliently released to cover the opening when the cage is removed from contact with the ventilating rack, whereupon the valve is closed.

19. The cage cover according to claim 18, wherein the frame includes a plurality of webs disposed across the perimeter of the cage, said support web being attached to at least one of the frame and the plurality of webs, at least one said web substantially crossing the perimeter, the support web extending between the frame and said at least one web, the filter membrane being bonded to the frame along substantially the entire said perimeter on a side directed outwardly of the cage toward the ventilating rack.

20. The cage cover according to claim 19, wherein the valve body includes a spring strip attached to the support web at a space from the opening in the filter membrane, the spring strip being normally disposed coplanar with the frame, the contact portion being attached to the spring strip at a space from an attachment thereof to the support web, the contact portion protruding through the opening in the filter membrane.