Cage and rack system for housing animals in cages having different widths

A ventilated cage and rack system. An embodiment of the invention may comprise a ventilated rack, the rack including at least one air exhaust plenum and at least one canopy disposed within the rack, the canopy being adapted to position a cage assembly below the canopy while maintaining a gap between the top of the cage assembly so as to permit air to be drawn into the air exhaust plenum from the interior of the cage assembly through the top of the cage assembly and to also permit ambient air to be drawn across the top of the cage assembly into the air exhaust plenum. The cage assembly comprises one of a first cage having a first width and a plurality of second cages having a second width, the second width being less than the first width.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to cage and rack systems for housing animals, and more particularly to a ventilated cage and rack system for housing animals.

2. Description of Related Art

It is well known in the art to house laboratory animals, such as mice and rats, in cages. It is also well known in the art to house the cages on racks. These cages are typically ventilated and, when placed in a rack, environmentally controlled (e.g., air-flow and air-exchange rate) by a fan system of the rack. In general, in such ventilated cage and rack systems, the rack fan system provides air under pressure to each of the cages within the rack, and exhausts air from the cages and the rack.

One such ventilated cage and rack system is disclosed in U.S. Pat. No. 6,158,387, assigned to Lab Products, Inc., in which a rack includes an air exhaust plenum and a canopy. The

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. canopy is capable of supporting a cage within the rack above the canopy, and also positioning another cage below the canopy so as to permit air to be drawn into the air exhaust plenum from the interior of the second cage through the top of the second cage and to also permit ambient air to be drawn across the top of the second cage into the air exhaust plenum. Cages for such systems may be referred to as cage level barrier cages because they provide for a barrier between the interior and exterior of the cage such that contaminants from the interior of the cage do not readily leave the cage, and likewise, contaminants from the exterior of the cage do not readily enter the interior of the cage.

This related ventilated cage and rack system was satisfactory. However, due to the manner in which the cage is positioned within the rack, only a single width of container may be accommodated by the rack.

In some situations, however, personnel may benefit from the use of cages having different widths. This situation may arise when a study is performed using animals of different species or sizes. A larger animal, or different species of animal, may require a larger cage size than another. Additionally, for the purposes of a study, it may be desirable to house a larger number of animals in one cage than in another, consequently requiring different size cages. Furthermore, in some circumstances, a single cage size may be used, with a larger than needed cage being used for containing animals. This strategy, however, typically leads to a waste of valuable space. Additionally, two different racks may be used, each rack accommodating a different size cage, but again, this strategy also tends to lead to the wasting of valuable space. As such, a need exists for an improved ventilated cage and rack system.

SUMMARY OF THE INVENTION

The present invention satisfies this and other needs. Generally, the present invention is directed to a ventilated cage and rack system wherein the rack has canopies that will facilitate placement of, for example, one wide cage, or two narrow cages under each canopy while still maintaining proper air flow into and out of the cages, as well as maintaining proper air flow from the ambient room environment over the top of the cages. By employing the invention, lab personnel may combine both wide and narrow cages within the same rack, thus saving time and space by not having to rely on two separate racks if the use of different sized cages is desired.

An embodiment of the invention may comprise a ventilated cage and rack system having ventilated rack, the rack including at least one air exhaust plenum and at least one canopy disposed within the rack, the canopy being adapted to position a cage assembly below the canopy while maintaining a gap between the top of the cage assembly so as to permit air to be drawn into the air exhaust plenum from the interior of the cage assembly through the top of the cage assembly and to also permit ambient air to be drawn across the top of the cage assembly into the air exhaust plenum. The cage assembly may comprise one of a first cage having a first width and a plurality of second cages having a second width, the second width being less than the first width.

The present invention accordingly comprises the features of construction, combination of elements, arrangement of parts, which will be exemplified in the disclosure herein, and the scope of the present invention will be indicated in the claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention are directed to a ventilated cage and rack system wherein the rack has canopies that will facilitate placement of one relatively wide cage, or two relatively narrow cages, under each canopy while still maintaining a beneficial air flow into and out of the cages, as well as maintaining a beneficial air flow from the ambient room environment over the top of the cages.

Reference is first made toFIGS. 1-3, wherein a ventilated cage and rack system, generally indicated at10, constructed in accordance with the invention is shown. Ventilated cage and rack system10includes an open rack12having a left side wall11and a right side wall13, a top15, and a bottom17. A plurality of posts19are disposed in parallel between top15and bottom17. Vertical posts19are preferably narrow and may comprise walls extending substantially from the front of rack12to the rear of rack12, or may each comprise two vertical members, one at or near the front of rack12and the other at or near the rear of rack12.

Ventilated cage and rack system10also includes a plurality of air supply plena40and air exhaust plena42alternately disposed in parallel between left side wall11and right side wall13substantially in the rear of rack12. Air is forced into air supply plena40by a blower44through an air supply conduit46, said air supply conduit46communicating with each air supply plenum40through a side wall of the rack12. Blower44preferably contains an air filter for supplying filtered air to rack12. Air is withdrawn from air exhaust plena42by a vacuum48through air exhaust conduit50, with each air exhaust conduit50communicating with each air exhaust plenum42through a side wall of the rack12.

A plurality of cage level barrier cages (cages20) may be positioned within rack12. Each cage is formed of a gas impermeable bottom portion22having an upstanding sidewall23and a filter cap24. Filter cap24may have an overhang26which extends over the top end of bottom portion22. Filter cap24is preferably a filter cap as described in more detail below, but may also be a filter cap as known in the art, such as the filter caps disclosed in U.S. Pat. Nos. 4,480,587 and 4,640,228, assigned to Lab Products, Inc.

Cages20are positioned within rack12by canopies generally indicated at30. Each canopy30shrouds one or more cages20bbelow a canopy30. Accordingly, each canopy30is shaped and positioned so as to substantially surround the filter cap24of the cage20bwhile maintaining a short gap h between a top25of filter cap24and canopy30. Gap h should be sufficient to allow movement of gases between canopy30and filter cap24, and in an exemplary embodiment gap h is 3/16 of an inch to ¼ of an inch. Canopy30profiles filter cap24and overlaps overhang26of filter cap24, preferably creating a tension fit against the sidewall23of bottom portion22of cage20b. The rear of canopy30is attached to air exhaust plenum42.

Canopies30are disposed in parallel columns in rack12between each pair of adjacent posts19, or between left side wall11and an adjacent post19, or between right side wall13and an adjacent post19. Each canopy30supports a first cage (or first and second cages)20aabove the canopy30in the rack12and shrouds the filter cap24of a second cage20bbelow the canopy30in the rack12. The bottom portion22of the first cage20arests on top of the corresponding canopy30. Of course, those canopies positioned at the top row of rack12do not support a cage20above them, and those cages20positioned on the bottom row of rack12are preferably supported by bottom17of rack12. When positioned in the rack, each cage20communicates with air supply plenum40through one or more cage couplings52. Generally, in accordance with the invention, if a relatively wide cage is used, a cage20would communicate with two couplings52. If, however, a relatively narrow cage20is used, cage20would typically communicate with a single coupling52. Such cage couplings are known in the art, and are disclosed, for example, in U.S. Pat. Nos. 4,989,545 and 5,042,429 assigned to Lab Products, Inc. Air supply plena40may also include means for delivering a supply of water to cages20through cage coupling52, as is also known in the art. Canopies30are preferably constructed of a lightweight, transparent material which is substantially rigid, such as clear plastic. Such clear plastic canopies provide enhanced visibility of cages20within rack system10and reduce the overall weight of rack system10.

Referring in particular toFIG. 3, a cage20is positioned within rack12and coupled to the air supply plenum40through cage coupling52. Blower44forces air into the air supply plenum40in the direction of arrow A, and air is consequently forced into cage20through cage coupling52in the direction of arrow B to supply air to animals within the cage. Vacuum48withdraws air from air exhaust plenum42in the direction of arrow C, thereby creating a negative pressure within the air exhaust plenum42. Ducts43are formed in air exhaust plenum42below the position at which canopy30is attached and communicating with gap h, permitting air below canopy30in gap h to be drawn into air exhaust plenum42causing a negative pressure within the space defined by canopy30. Thus, air is drawn from the cage20below the canopy30through filter top24in the direction of arrows D and into the air exhaust plenum42. Ambient air from the room in which rack12is situated is also drawn across the top25of filter cap24through the open front of canopy30in the direction of arrow E (this process is also illustrated inFIG. 16).

Because canopy30effectively surrounds filter cap24including overhang26, canopy30effectively isolates filter cap24from the remainder of the cage20which it covers, as well as from the remainder of cages20within the rack12. Accordingly, gases passing from cage20around or underneath overhang26remain within canopy30until removed by air exhaust plenum42through ducts43. Additionally, because overhang26is contained within canopy30when cage20is positioned therein, contamination due to gas exchange between adjacent cages is severely reduced. By providing a ventilated rack and cage system utilizing a negative pressure air exhaust plenum in which air is drawn from a small confined space provided by the canopies30and filter tops24, an open ventilated rack is provided which also provides for personnel protection as well as animal protection.

Referring again toFIG. 3, an embodiment of canopy30, generally indicated at30a, comprises a top plate31a. Top plate31aextends from the air exhaust plenum42above ducts43at least the length of filter cap24of a cage20positioned beneath the canopy30a, as well as at least to the front end of the bottom portion of a cage20positioned above the canopy30a. Top plate31ais preferably as long as a cage20itself, including filter cap24. Canopy30afurther comprises a left side plate33aand a right side plate35awhich each depend substantially perpendicularly from opposite side edges32aand34aof top plate31a. Side plates33aand35aare preferably disposed at a distance from each other which is substantially the same as or slightly greater than the width of filter cap24. Canopy30aalso comprises lips37aand39awhich each extend perpendicularly from side plates33aand35arespectively toward cage20. Lips37aand39aare disposed so as to extend underneath at least a portion of the overhang26of filter cap24. Lips37aand39aare substantially parallel to top plate31aand are each preferably disposed at a distance from top plate31awhich is substantially the same as or slightly greater than the height of filter cap24plus gap h. In this manner, any gases escaping from overhang26are held in the canopy by lips37aand39aand will be drawn away through ducts43in air exhaust plenum42at the rear of canopy30a.

Canopy30ais preferably mounted to air plenum42at the rear and to two posts19at the front of rack12. Each post19preferably comprises a vertical T-beam, with a first face19abeing disposed substantially parallel to the direction of insertion of a cage20into rack12(which is parallel to the direction indicated by arrow E), and a second face19bbeing disposed substantially perpendicular to said direction of insertion. Each side of face19bis provided with notches19cfor supporting canopy30atherein. To maximize horizontal cage density within rack12, notches30apreferably extend as close to face19aas possible, and face19aof post19is preferably made as narrow as possible while still providing structural support for rack12. By providing such a notched T-beam post19on each side of canopy30a, canopy30amay be supported on both sides from the front of rack12. Other means of providing the support of posts19are contemplated by the invention. For example, a notched L-beam post19could be used, thereby providing support to only one side of canopy30afrom the front of the rack, or canopies30acould be screwed to a flat vertical panel disposed parallel the cage insertion direction and extending from the top to the bottom of rack12.

Reference is now made toFIGS. 4 and 5in which an embodiment of a cage is shown. Specifically cage bonnet200includes a retainer210, a top220, a filter240disposed there between, and a shield250affixed to the interior of top220. Top220is again preferably formed of clear plastic which is substantially rigid, but permits a modest degree of flexure when tortional forces are applied thereto. Top220has a perforated top wall222with perforations224forming a grid array. Respective opposed pairs of side walls226depend substantially orthogonally from top wall222. The surface formed on top220for resting bonnet200on cage bottom3includes a continuous lateral peripheral flange238extending generally perpendicularly outwardly from side walls226. A continuous flange230depends from lateral peripheral flange238to encompass the open top16of cage bottom3. In certain embodiments, a hole236is provided through top wall222and is dimensioned to receive a rivet239.

With reference toFIG. 6, there is shown a portion of an embodiment of the ventilated cage and rack system110of the invention. Cage and rack system110has right side wall113, bottom wall117and a top wall115(for sake of clarity, a small rack, or a portion of a larger rack, is shown). Also, only a small portion of vertical post119is shown.

In accordance with an embodiment of the invention, a canopy310is disposed in a vertical array in cage and rack system110. Importantly, a cage assembly comprising a single wide cage123is disposed below a first canopy310, while a cage assembly comprising two narrower cages122is disposed below a second canopy310′ located directly below first canopy310. In certain embodiments, both first canopy310and second canopy310′ are of the same design. In certain embodiments, narrow cage122may have a floor area of substantially 80 square inches, while wide cage123may have a floor area of substantially 210 square inches. In other embodiments, narrow cage122may have a floor area of substantially 75 square inches, while wide cage123may have a floor area of substantially 180 square inches.

As described above with respect an embodiment of a ventilated cage and rack system, air enters into the cages123,122via air supply plena340, and in turn cage coupling52. Air is exhausted out of the bonnets200of cages123,122, under canopies310and310′, and into a duct43in air exhaust plena342. As also described above, air also travels from the ambient room environment across the top of cage bonnet200, and into air exhaust plena342.

As described above, canopies310,310′ are shaped and disposed such that the air leaving cages123,122and the ambient room environment are advantageously channeled to exhaust plena342. Importantly, both canopy310and canopy310′, which are of the same design, can facilitate an advantageous exhausting air flow whether a single wide cage123, or two narrower cages122are disposed thereunder.

Additionally, cage123may be advantageously retained in position by cage lock310, which engages with cage123at one side. In contrast, cages122may be retained in proper position in the rack by cage locks500,502.

Turning toFIGS. 8-10, and in particularFIGS. 7 and 8, canopy310is illustrated in greater detail. Canopy310may have top plate316, and left and right side walls312,314extending orthogonally away therefrom, at opposing edges of top plate316. Lips326,328extend orthogonally from side walls312,314respectively and in a direction substantially parallel to top plate316. Canopy310may also have channeling element330for channeling air away from a region bounded by right channel wall334and left channel wall332of channeling element330.

Canopy310may be secured or attached to air exhaust plena42of rack12by way of tabs346and slots348defined in top plate316. Tabs346are designed and dimensioned to fit into corresponding slots defined in rack12(not shown), preferably in air exist plena42. Likewise, slots348of top plate316are designed and dimensioned to mate with corresponding structures (not shown) on rack12. Accordingly, tabs346and slots348facilitate the securing of canopy310to rack12, in a manner that is known to those skilled in the art.

A reinforcement member344may be disposed on front edge342of canopy310. In an embodiment of the invention, reinforcement member344may be formed of metal or relatively rigid material to increase the overall bending rigidity of top plate316such that canopy310may support the weight of a wide cage123, or two narrow cages122. Reinforcement member344may be formed as an elongated U shape to snugly fit about front edge342and provide bending support to top plate316.

Positioning recesses350,352may be defined in top plate316and extend in a substantially parallel manner from front edge342to a rear edge358of upper surface324of top plate316. Positioning recesses350,352facilitate the sliding placement into and removal from rack12of either a wide cage123or two narrow cages122on top of canopy310.

With reference toFIG. 9, (and continued reference toFIGS. 1 and 6) channeling element330, rear channel wall338and flow tabs354are discussed in more detail. As is discussed above, the invention advantageously controls air flow into and out of cages122,123such that the environments of individual cages as well as that of the ambient room environment may be satisfactorily isolated from each other. To achieve this goal, certain optimum air flow characteristics can be determined for animal cages, based upon the size of the cage, as a matter of application specific design choice.

As will be described in more detail below, canopy310also has rear channel wall338and flow tabs354extending down from lower surface322of top plate316of canopy310. Rear channel wall338and flow tabs354work in conjunction with channeling element330to facilitate proper air flow from and about cage20.

When two narrow cages122are used with a single canopy310′, air is pulled from the room toward air exhaust conduit50, the air passed through the space above cage bonnet200of cage122, and canopy310′. With reference toFIG. 9, channeling element330facilitates the flow of ambient room air in direction H. Channeling element330may also facilitate the positioning of the cages122within the rack. In an embodiment of the invention, channeling element330preferably has a curved or rounded front channel wall336attached to left and right channel walls332,334to facilitate smooth air flow about channeling element330. Channel walls332,334are designed and dimensioned to align with the opposed edges of continuous flange230of filter top bonnets200of the two adjacent cages. Without the use of channeling element330, air would flow into center channel area340between channel walls332,334. If air were permitted to flow in this region, proper air flow from the cages122might not be maintained as some air would not be channeled across the cage122, but would tend to flow in other directions. Additionally, additional vacuum pressure would be required to create the desired air flow characteristics. In addition, flow tabs354and rear channel wall338are likewise designed and dimensioned to align with respective portions of continuous flange230of bonnet200, and facilitate proper air flow by serving to channel air from the room and cages122to air exhaust conduit50. As can be seen with reference toFIG. 10, lips326,328of canopy310′ also may facilitate proper air flow as portions of the air flow that might otherwise escape from under canopy310′ are directed back under the canopy310′.

With reference toFIG. 11-15C, and specifically toFIGS. 11-12B, there is shown an embodiment of a cage bonnet400constructed in accordance with the present invention. Cage bonnet400is similar in form and function to that of cage bonnet200described above (seeFIG. 5), with a difference being that cage bonnet400is designed and dimensioned to be used with a wide cage123and bonnet200is designed and dimensioned to be used with a narrow cage122(seeFIG. 6). Additionally, as may be seen with reference toFIG. 11, bonnet400has a top420having two flow portions428,429at top wall422. Flow portions428,429are separated by channel470, which is defined between and adjacent to flow portions428,429on top wall422of top420. In an embodiment of the invention, each flow portion428,429of top430may be designed and dimensioned to accept retainers210, filters240, and filter shields250of the same size and dimension as that of cage123as described above, a difference being that top420is designed and dimensioned to receive two each of these components, while, as described above, each top220of cage122is only designed and dimensioned to receive one each of these components. A beneficial result of this embodiment is that many of the same components (e.g., retainers210, filters240and filter shields250) may be used within the system for both narrow cages122and wide cages123, thus allowing personnel to reduce storage space for components. Additionally, as described above, a beneficial and consistent air flow dynamic may be achieved with the use of either two narrow cages122, or a single wide cage123under a single canopy310.

Top420may have a pair of securing latches478resiliently extending from the front of continuous flange430such that a handle480may be flexed away from top420, retuning to its original position upon release, and facilitating engagement of latching tab482upon the edge of cage123. Top420may also have perforations424within top wall422, as shown, or relatively smaller perforations as is shown with respect to top220(seeFIG. 5).

With reference toFIGS. 13A and 13B, the top wall422of top420may comprise a lattice of lateral supports488and cross members490. Additionally, top wall422may have two pairs of diagonal members492extending diagonally between opposed corners of flow portions428,429, each pair connecting centrally at a hub portion494. This arrangement of lateral supports488, cross members490and hub portion494with perforations424formed therebetween provides for beneficial structural support of top420while allowing for a beneficial air flow through filters240, as described above.

With reference toFIGS. 14A-15C, there is shown a top420of a cage bonnet400having two filter shields250retained thereunder by retention tabs486. Two filter retainers210are disposed above top420, with two filters240(not shown) sandwiched respectively therein.

Thus, a ventilated cage and rack system has been described having canopies that will facilitate placement of one wide cage, or two narrow cages under each canopy while still maintaining proper air flow into and out of the cages, as well as maintaining proper air flow from the ambient room environment over the top of the cages. By employing the invention, lab personnel may combine both wide and narrow cages within the same rack, thus saving time and space by not having to rely on two separate racks if the use of different sized cages is desired. Additionally, the cage tops for both the wide and narrow cages share many of the same components, thus reducing manufacturing costs and minimizing the need for storage space for components.

With reference toFIG. 17, there is shown an embodiment of a diet delivery module600in accordance with the invention. Diet delivery module600is formed with body602, preferably formed of a clear plastic that is autoclavable so that it can be sterilized or sanitized to provide a clean environment in which the animals can be maintained. Diet delivery module600is formed with two fluid compartments604at opposing sides of diet delivery module600. Fluid compartments604can have rounded bottoms605that facilitate the flow of fluids to apertures607. A sipper tube (not shown) or other fluid dispensing device may be disposed within apertures607such that animals be access fluids disposed within fluid compartments604. A food module606is disposed in the center of diet delivery module600, between the fluid modules604. Body602has an upper peripheral lip608and flanges610extending outward from peripheral lip608at opposing sides of diet delivery module600. Diet delivery module600also has stabilizing flange612extending from peripheral lip608and extending in a longitudinal manner from one end flange610to the other end flange610.

An embodiment of a cage bottom620is illustrated inFIGS. 18 and 19. Recesses622,622′,624,624′ are defined in upper lip621of cage bottom620. Diet delivery module600may be disposed in cage bottom620by aligning each of the flanges610of diet delivery module600in one of the recesses624,624′ or622,622′ of cage bottom620.

With reference toFIG. 20, there is shown another embodiment of a diet delivery module630. Diet delivery module630is similar to the previously described diet delivery module600. Diet delivery module630comprises fluid modules634disposed at opposing ends of diet delivery module630. Feed module636is disposed at a center of diet delivery module630between the opposing fluid delivery modules634. Flanges640extend from the opposing ends of diet delivery module630, extending from peripheral lip631. Diet delivery module630also has recesses644,644′ and646,646′ defined in peripheral lip631.

With reference toFIGS. 21-24, diet delivery module630may be disposed in cage bottom650by disposing the flanges640of diet delivery module630into the recesses652,652′ defined in peripheral lip651of cage bottom650. Wire food module660(seeFIG. 22) may be disposed in feed module636of diet delivery module630. Because, when diet delivery module630is disposed in cage bottom650, diet delivery module630is positioned at a center of cage bottom650, space is free in cage bottom650to the right and left of diet delivery module630. This free space allows for easy, relatively unobstructed viewing of an animal within cage bottom650. Also, when diet delivery module630is positioned at a center of cage bottom650, gases entering cage bottom650through cage couplings662may enter without being obstructed by diet delivery module650. Further, because diet delivery module630may be positioned at a center of cage bottom650, additional modules with flanges adapted for use with the embodiment may be disposed in the pairs of recesses658and638defined in cage bottom650and diet delivery module630respectively. An example of such a module (or modules) that may be so positioned is an animal perch as is described in U.S. patent application Ser. No. 10/683,517, the contents of which are hereby incorporated by reference herein. Accordingly, a system has been shown which provides a flexible environment for positioning an array of modules along with a cage bottom and diet delivery module for an animal.

In certain embodiments, peripheral lib608of cage bottom650may have disposed thereon lifting extensions654disposed on peripheral lip608at opposing sides of cage bottom650. The gripping recesses432of continuous flange430of cage bonnet400(seeFIG. 11), preferably align with the lifting extensions654such that personnel may lift a cage bottom650having a bonnet400disposed thereon without displacing bonnet400from cage bottom650. Accordingly, a cage bottom650and cage bonnet400combination may be lifted by personnel without breaching the seal between the two. In addition, secure lifting of the cage bottom650is facilitated, and consequently, accidental dropping of cage bottom650is made less likely.