U.S. patent application number 10/765321 was filed with the patent office on 2005-03-31 for animal isolation and caging system.
Invention is credited to Campbell, Neil, Dietrich, Rick, Gabriel, George S., Gabriel, Richard, Gerringer, Rodney, Irwin, Lynn, Murray, Dale R., Park, Chin Soo.
Application Number | 20050066909 10/765321 |
Document ID | / |
Family ID | 24834246 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050066909 |
Kind Code |
A1 |
Gabriel, George S. ; et
al. |
March 31, 2005 |
Animal isolation and caging system
Abstract
An animal isolation and caging system which maximizes cage
density within a ventilated rack is provided. The rack includes at
least one air exhaust plenum, and at least one canopy disposed
within the rack for ventilation of the cages housed in a rack
system. The rack is capable of supporting a first cage within the
rack below a first canopy, and also positioning a second cage below
a second canopy. The filter top of the first cage provided by the
invention also provides a filter retainer having a filter top
retainer wall designed to be in contact with a first canopy unit
forming an enclosed space so configured as to create an enclosed
space from which the animal isolation and caging system of the
invention creates a zone of negative pressure so as to permit air
to be drawn into an air exhaust plenum or duct from the interior of
the first cage through the top of the first cage.
Inventors: |
Gabriel, George S.;
(Seaford, DE) ; Campbell, Neil; (Eden, MD)
; Park, Chin Soo; (Salisbury, MD) ; Irwin,
Lynn; (Seaford, DE) ; Gerringer, Rodney;
(Belcamp, MD) ; Murray, Dale R.; (Elkton, MD)
; Gabriel, Richard; (Laurel, DE) ; Dietrich,
Rick; (Woodbine, MD) |
Correspondence
Address: |
Steven B. Pokotilow
Stroock & Stroock & Lavan LLP
180 Maiden Lane
New York
NY
10038
US
|
Family ID: |
24834246 |
Appl. No.: |
10/765321 |
Filed: |
January 26, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10765321 |
Jan 26, 2004 |
|
|
|
09705617 |
Nov 3, 2000 |
|
|
|
6729266 |
|
|
|
|
Current U.S.
Class: |
119/419 |
Current CPC
Class: |
A01K 1/031 20130101 |
Class at
Publication: |
119/419 |
International
Class: |
A01K 001/03 |
Claims
What is claimed is:
1. A filter cap for an open-top cage comprising: a substantially
rigid filter frame adapted to cover said open top of said open top
cage, said filter frame having a body portion with a perforated top
wall and side walls extending therefrom forming an open bottom end,
a substantially rigid filter retainer sized to fit upon filter
frame and to substantially cover said perforated top wall of said
filter frame, said filter retainer having an upper surface with
perforations substantially coextensive with the perforations on the
top of said filter frame top wall, said filter retainer also having
side walls extending from its upper surface forming an open bottom
end, the perforations in said filter retainer being substantially
in alignment with the perforations in said filter frame when said
filter retainer is mounted on the top of said filter frame; a chew
shield being detachably secured to the undersurface of said filter
frame so as to prevent animals within said open top cage from
damaging said filter cap, said chew shield being sized to
substantially cover the interior dimensions of said open top of
said open top cage and having a lower surface with perforations
substantially coextensive with the perforations found in said
filter frame; a first attachment means for detachably securing said
chew shield to said filter frame; and a second attachment means for
detachably securing the filter retainer to said filter frame to
permit enclosure of a sheet of filter material therebetween, said
attachment means being integrally formed in said filter frame and
said filter retainer.
2. The filter cap of claim 1, wherein said first attachment means
comprises a plurality of snap rivets utilized to affix said chew
shield to said filter frame.
3. The filter cap of claim 2, wherein said first attachment means
is further comprised of a material selected the group consisting
of: a). nylon; b). metal; c). high impact plastic; and d).
ceramic.
4. The filter cap of claim 1, wherein said second attachment means
comprises at least one detent formed on at least one side wall of
said filter retainer, and at least one slot formed in at least one
side wall of said filter frame disposed so as to receive said
detent therein when said filter retainer is mounted on said filter
frame.
5. The filter cap of claim 1, wherein said second attachment means
comprises at least one detent formed in at least one side wall of
said filter frame, and at least one slot formed in at least one
side wall of said filter retainer disposed so as to receive the
detent therein when said filter retainer is mounted on said filter
frame.
6. The filter cap of claim 1, wherein said perforations on the
lower surface of said chew shield are sufficiently small to prevent
an animal within said cage body from causing s substantial damage
to said filter material enclosed between said filter frame and said
filter retainer.
7. The filter cap of claim 1, wherein said filter retainer, said
filter frame and said chew shield have sufficient flexure to allow
said filter retainer, said chew shield and said filter frame to
flex relative to each other.
8. The filter cap of claim 1, wherein said chew shield is composed
of machined metal.
9. The filter cap of claim 1, wherein said filter cap and said
filter frame are made of transparent material.
10. An animal isolation and caging system comprising: a ventilated
rack, said rack including at least one air exhaust plenum; at least
one canopy attached to said rack for ventilation of cages housed in
a said caging system wherein said rack is capable of supporting at
least one cage level barrier cage within said rack below said at
least one canopy while maintaining a gap between the top of said at
least one cage and said at least one canopy so as to permit air to
be drawn into said air exhaust plenum from the interior of said at
least one cage through a top wall of the top of said at least one
cage; and a filter cap for an open-top cage, said filter cap
comprising: a substantially rigid filter frame adapted to cover
said open top of said open top cage, said filter frame having a
body portion with a perforated top wall and side walls extending
therefrom forming an open bottom end, a substantially rigid filter
retainer sized to fit upon filter frame and to substantially cover
said perforated top wall of said filter frame, said filter retainer
having an upper surface with perforations substantially coextensive
with the perforations on the top of said filter frame top wall,
said filter retainer also having side walls extending from its
upper surface forming an open bottom end, the perforations in said
filter retainer being substantially in alignment with the
perforations in said filter frame when said filter retainer is
mounted on the top of said filter frame; a chew shield being
detachably secured to the undersurface of said filter frame so as
to prevent animals within said open top cage from damaging said
filter cap, said chew shield being sized to substantially cover the
interior dimensions of said open top of said open top cage and
having a lower surface with perforations substantially coextensive
with the perforations found in said filter frame; a first
attachment means for detachably securing said chew shield to said
filter frame; and a second attachment means for detachably securing
the filter retainer to said filter frame to permit enclosure of a
sheet of filter material therebetween, said attachment means being
integrally formed in said filter frame and said filter retainer.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a Division of co-pending application
Ser. No. 09/705,617, filed Nov. 3, 2000, entitled "Animal Isolation
and Caging System," presently allowed, the contents of which are
hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates generally to an animal isolation and
caging system, and more particularly to an open rack system which
maximizes both cage density within the rack and useful volume
within each cage while providing protection for both personnel
attending to the system and the animals contained within the cages
from the contamination of the cages themselves and from the release
of allergens, dander or other contaminants from an individual cage
or rack system housing a plurality of cages through the use of a
canopy capture system.
BACKGROUND OF THE INVENTION
[0003] Animal isolation and caging systems are well known in the
art. Such systems include the animal isolation and caging systems
provided for in the ventilated rack systems disclosed in U.S. Pat.
Nos. 5,349,923 and 5,165,362 assigned to Lab Products, Inc., in
which an open rack system including a plurality of shelves, each
formed as an air plenum, is provided. Air ventilation is provided
directly to animals within each cage assembly by allowing air to
travel within each shelf to a plurality of predetermined positions
within the rack. At least one cage level barrier having a filter
cap is positioned in a rack, so that the rack and the air conduits
integral within it removes air disposed adjacent the filter cap. A
cage guide is formed in substantially the same shape as the filter
cap and is affixed to the bottom of a shelf of the rack holding a
cage so that when the barrier cage is placed within the ventilated
rack, it is positioned within the cage guide. The cage guide is
separated from the filter cap of a cage by a distance. The air
plenum shelf is provided with a vacuum to partially remove gases,
dander, allergens and other compounds that originated in one or
more cages and moving to a location outside the cage.
[0004] The prior art animal isolation and caging systems are
satisfactory. However, because each shelf acted as an air plenum,
each shelf required a certain height within the rack to allow for
air to travel therethrough, and due to a lack of a enclosed canopy
or other gas capture system, animals as well as workers maintaining
cages could be exposed to high levels of allergens, disease causing
agents, inappropriate chemical signaling agents (e.g., pheromones),
dander or other undesirable compounds released from the animal
cages themselves or present in the air in proximity to the cages.
The answer provided by the prior art was to proportion the combined
height of each shelf and the cage guides mounted below each shelf
to maximize vertical cage density, thereby maximizing the effect of
negative pressure removal of contaminants, without providing for a
means of creating a capture system for contaminants. Another
problem provided by such prior art systems is the use of large
amounts of opaque material or metal that hinder visual inspection
of a high cage density rack system. A system that provided a "see
through" system that would allow an operator to more easily
determine the condition of individual animals and the environment
in individual cages.
[0005] Filter cap assemblies for animal cages used within animal
isolation and caging systems are also well known in the art. One
such filter cap is disclosed in U.S. Pat. No. 4,640,228, assigned
to Lab Products, Inc., in which a top body with a perforated filter
cap top wall is provided. A sheet of filter material is sandwiched
between a retainer and the lower surface of the perforated filter
top wall of the top body. The retainer is detachably mounted inside
the filter body in flush abutment with the filter material placed
against the lower surface of the filter top wall of the top body.
The retainer comprises a narrow border portion and flat cross arms
which intersect at an integral central portion.
[0006] This prior art filter top was satisfactory. However, because
the retainer was secured to the filter cap body on the interior of
the filter cap body, changing a filter with an animal within the
cage was inhibited because the entire filter cap required removal
from the cage to remove the retainer and change the filter.
Moreover, because the retainer was substantially open, the bottom
side of the filter was substantially exposed to animals within the
cage who might damage the filter, rendering it ineffective and
resulting in contamination or requiring additional an structure
such as a wire bar lid for protection of the filter.
[0007] Another solution to the filter changing problem is found in
U.S. Pat. No. 5,797,349, assigned to Lab Products, Inc., in which a
filter changing station is provided in which the filter protecting
an individual cage can be changed without opening the entire cage.
The changing station disclosed in this prior art is, however,
difficult to operate and often results in the ripping of a used
filter or the improper placement of a new filter in the filter
cap.
[0008] Another such filter cap is disclosed in U.S. Pat. No.
4,480,587, assigned to Lab Products, Inc., in which a cap body with
an open top portion provided with a ledge and cross arms is
provided. A filter is detachably secured to the cap body by an
overlaying protective plate member which is fastened over the ledge
and cross arms using a plurality of fasteners, such as threaded
bolts which pass through holes in the plate member, filter and cap
body and secured by respective nuts.
[0009] This prior art filter cap was also satisfactory. However,
because separate threaded bolt fasteners were used to mount the
protective plate to the filter cap body, personnel changing a
filter were required to use special tools to remove the protective
plate to release the filter. The use of such tools required
additional resources and was time-consuming. Moreover, because the
cap body had a substantially open top and no specific filter frame,
the bottom side of the filter in this design was also unprotected
from animals within the who might damage the filter and render it
ineffective during a filter changing operation. In addition, the
substantially open top inhibited changing a filter with an animal
within the cage because of the possibility that the animal could
escape through the open top of the cage body during a filter
changing procedure.
[0010] Typically, the cages in a rack system must be removable from
the rack system to provide access to the animals for feeding and
testing, and to the cages for cleaning, maintenance and transport.
However, it also required that the rack air source and/or water
source mate with the cage to provide air and water to the cage. To
accommodate this requirement it is known in the art to provide a
structure so that the valve in each cage is connected to an air
and/or water plenum on the rack by a coupling system. In such a
system, each cage is connected to the plenum by pushing the cage
into a rack until the coupling at the rear of the cage is connected
to the coupling provided on the plenum to make mating contact with
a valve system containing connections to water and air sources. The
couplings are disengaged by simply pulling the cage out of the
rack, which closes a valve within the plenum coupling to prevent
the escape and contamination of water and air.
[0011] In the prior art, cages designed for ventilated cage and
rack systems also failed to provide for securely dividing a cage
between two or more animals. The designs provided in the prior art,
as typified by U.S. Pat. No. 6,041,741, assigned to Lab Products
Inc., disclose only one source of food and water respectively
within a given cage. This may be undesirable in those situations
where it is desirable to more effectively utilize a cage footprint
in compliance with appropriate federal guidelines and increase
occupancy of a given caging system, or in situations where dividing
animals is necessary for research ends' or the animals' welfare.
Accordingly, it is desirable to provide a double-sided ventilated
caging system including a cage-level barrier cage with a specific
footprint that complies with appropriate federal guidelines while
simultaneously being available to house a multiplicity of different
animals typically used in scientific studies and separate them into
at least two compartments through use of a removable divider
element that is contoured to the cage system and will prevent any
caged animals from gaining purchase on the divider and chewing
through it or otherwise damaging it. The compartments formed as a
result of the removable divider element being provided with
individual food and water sources.
[0012] Filter top locking mechanisms have also been designed to
prevent an individual cage from being opened from within by an
animal held there or accidentally opening when a worker uncouples a
cage from the plenum and the rack in which it is located. However,
these prior art designs have been large, cumbersome and expensive.
Accordingly, it is desired to provide a simple, self-contained
animal cage locking mechanism which enables an operator to lock a
cage and keep it securely sealed yet easily manipulated by a worker
handling individual cages who needs to maintain the cages and/or
the animals within them. Such a locking mechanism should maintain
engagement despite bumping, jarring or improper removal of an
individual cage, and which should also be less cumbersome and more
easily replaced if lost or damaged.
[0013] Accordingly, it is desired to provide a animal isolation and
caging system which maximizes the stacking density of cages within
the rack, while providing for the removal of unwanted contaminants
from circulating in a laboratory environment, in the rack system
itself, and among cages. It is also desirable to provide a
double-sided ventilated caging system including cage-level barrier
cages that minimize the use of opaque materials or metal which
hinder visual inspection of a animal isolation and caging system.
It is also desired to provide a modified filter cap for animal
cages used in a animal isolation and caging system which permits
easy changing of the filter while an animal is within the cage and
which protects the filter in use and the filter top itself from
damage caused by animal(s) housed in an individual cage. It is also
desired to provide a cage design footprint that will house up to
two full grown rats in compliance with appropriate federal
regulations, such a cage design also providing for a divider
element that securely divide the cage into at least two equal
compartments, each compartment having an individual food and water
source. It is further desired to provide a simple animal cage
locking mechanism which enables an operator to securely move,
transport, or manipulate an individual cage that is itself easily
and inexpensively replaced.
SUMMARY OF THE INVENTION
[0014] Generally speaking, in accordance with the instant
invention, an animal isolation and caging system which maximizes
cage density while minimizing the use of opaque materials and metal
within a ventilated rack is provided. The rack includes at least
one air exhaust plenum, and at least one canopy disposed within the
rack for ventilation of the cages housed in a rack system. The rack
is capable of supporting a first cage within the rack below a first
canopy, and also positioning a second cage below a second canopy.
The filter top of the first cage provided by the invention also
provides a filter retainer having a filter top retainer wall
designed to be in contact with a first canopy unit forming an
enclosed space so configured as to create an enclosed space from
which the animal isolation and caging system of the invention
creates a zone of negative pressure so as to permit air to be drawn
into an air exhaust plenum or duct from the interior of the first
cage through the top of the first cage.
[0015] Generally speaking, in accordance with the instant
invention, a filter cap for an open-top cage is further provided.
The filter cap includes a substantially rigid filter frame bonnet
adapted to cover the open top of the open-top cage. The filter
frame bonnet includes a body portion with a perforated top, and
side-walls extending therefrom forming an open bottom end. The
filter cap also includes a substantially rigid filter retainer
sized to fit upon the filter frame bonnet and to substantially
cover the perforated top of the filter frame bonnet, the filter
retainer also having a filter top retainer wall. The filter
retainer includes a top end with perforations so as to allow the
passage of air, and side walls extending from the top end of the
filter retainer forming an open bottom end, the perforations in the
filter retainer being substantially in alignment with the
perforations in the filter frame bonnet when the filter retainer is
mounted on the top of the bonnet. The filter cap further includes
attachment means for detachably securing the filter retainer to the
rest of the filter cap body to permit enclosure of a sheet of
filter material therebetween, the attachment means being integrally
formed in the bonnet and the filter retainer, typically, being
configured as snap rivets and or detents formed in a molded cage
body.
[0016] Generally speaking, in accordance with the instant
invention, the filter cap is further configured to provide for a
detachable filter top lock designed to secure the filter cap to the
cage body of the invention. The filter top lock being easily
released by an operator, it being readily apparent as to whether a
cage is properly secured. The filter top lock of the invention
enabling an operator to securely move, transport, or manipulate an
individual cage. The filter cap of the current invention also
includes a chew shield configured to securely attach to the filter
cap through the use of a plurality of snap rivets. The chew shield
being designed to cover the open top of the cage body and able to
prevent animals from having access to and/or damaging the filter
frame, filter or filter retainer. The chew shield further having
perforations substantially in alignment with the perforations in
the filter frame.
[0017] Accordingly, it is an object of the invention to provide a
animal isolation and caging system which maximizes the density of
cages and animals housed within a ventilated rack system. To
maximize animal density the current invention provides for a
double-sided ventilated caging system including a cage-level
barrier cage with a specific footprint that complies with
appropriate federal guidelines while simultaneously being available
to house at least two large rats of the type used in scientific
studies and separate them into at least two compartments through
use of a removable divider element that is contoured to the cage
system and will prevent any caged animals from gaining purchase on
the divider and chewing through it or otherwise damaging it. The
compartments formed as a result of the removable divider element
being provided with individual food and water sources.
[0018] Another object of the current invention being to provide a
double-sided ventilated caging system including cage-level barrier
cages that minimizes the use of opaque materials or metal which
hinder visual inspection of the animal isolation and caging system
of the invention.
[0019] Another object of the invention is to provide a animal
isolation and caging system which does not require distinct
shelving for positioning and supporting cages within the rack and
which thereby maximizes the proportion of space within the rack
which may be occupied by cages.
[0020] Another object of the invention is to provide for a
rotatable dosage feeder for an animal cage which selectively
provides multiple exact dosages of food to an animal within a cage
of the invention. The feeder has a frame dividing a cage interior
side from a cage exterior side. A food holding member is rotatably
mounted on the frame and holds a plurality of measured dosages of
food. At least a portion of the food holding member extends within
the cage to the cage interior side of the frame. In a preferred
embodiment the food holding member is a carousel.
[0021] A further object of the invention is to provide a animal
isolation and caging system with canopies which position and
support cages within the rack without additional shelving and
which, through canopy capture system, guide exhaust air drawn from
cages within the rack through a canopy capture system into an air
exhaust duct to remove exhaust air from the rack without
contamination of operating personnel or cross-contamination between
cages within the rack.
[0022] Still another object of the invention is to provide a filter
cap for an open-top cage which permits a filter to be securely
mounted yet easily and quickly changed with a filter removal device
easily utilized by an operator.
[0023] A still further object of the invention is to provide a
filter cap for an open-top cage which permits replacement of a
filter while animals are within the cage and which prevents such
animals from escaping during filter replacement.
[0024] Yet another object of the invention is to provide a filter
cap for an open-top cage which protects the filter from damage
caused by animals within the cage through the use of a chew
shield.
[0025] Still other objects and advantages of the invention will in
part be obvious and will in part be apparent from the
specifications and drawings. The invention accordingly comprises
the features of construction, combination of elements, and
arrangement of parts which will be exemplified in the constructions
hereinafter set forth, and the scope of the invention will be
indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] For a fuller understanding of the invention, reference is
had to the following description taken in connection with the
accompanying drawings, in which:
[0027] FIG. 1 is an exploded perspective view, of a single cage of
the animal isolation and caging system constructed in accordance
with the present invention;
[0028] FIG. 2 is a plan front view of a cage of the current
invention showing the diet delivery system water bottle, and cage
coupling;
[0029] FIG. 3 is a top plan view of a filter cap in accordance with
the current invention;
[0030] FIG. 4 is a side view of a cage of the current invention
showing the proximity of the diet delivery system and the cage
coupling;
[0031] FIG. 5 is a top plan view of a cage body of the current
invention;
[0032] FIG. 6 is a side plan view of a cage body of the current
invention;
[0033] FIG. 7 is a perspective view of a cage body of the current
invention;
[0034] FIG. 8 is a side view of a cage body of the current
invention;
[0035] FIG. 9 is a top plan view of a diet delivery system of the
invention;
[0036] FIG. 10 is a front plan view of a diet delivery system of
the invention;
[0037] FIG. 11 is a perspective view of a diet delivery system of
the invention, including water bottle with sipper tube;
[0038] FIG. 12 is a side plan view of a diet delivery system of the
invention;
[0039] FIG. 13 is a top plan view of a filter cap of the current
invention including a secured filter top lock;
[0040] FIG. 14 is a side plan view of a filter cap of the current
invention including a rear lock tab;
[0041] FIG. 15 is a perspective view of the filter cap of the
current invention showing the an attached filter top lock of the
invention;
[0042] FIG. 16 is a front view of the filter cap of the current
invention with the filter top lock of the current invention;
[0043] FIG. 17 is a plan top view of the filter top lock portion of
the animal isolation and caging system of the invention;
[0044] FIG. 18 is a plan front view of a filter top lock element of
the current invention detached from the filter cap and cage body of
the current invention;
[0045] FIG. 19 is a perspective view of the filter top lock element
of the current invention;
[0046] FIG. 20 is a plan side view of the filter top lock element
of the current invention;
[0047] FIG. 21 is a front view of a cage of the current invention,
including a partial cutaway of the filter cap, and diet delivery
system, also showing a divider element separating a cage of the
invention into two compartments;
[0048] FIG. 22 is a top view of a cage of the current invention
with detents for holding the filter retainer of the cage top onto
the filter frame of the invention;
[0049] FIG. 23 is a side view of a cage of the current invention
with a partial phantom of the divider element embodiment of the
invention used to separate a cage of the animal isolation and
caging system of the present invention, including a view of the
diet delivery systems put in place for multiple animals when the
divider element is utilized;
[0050] FIG. 24 is a plan top view of a divider element embodiment
of the current invention;
[0051] FIG. 25 is a plan side view of a divider element embodiment
of the current invention, with directional arrow A indicating the
front of the cage body of the current invention;
[0052] FIG. 26. is a perspective view of a divider element of the
current invention;
[0053] FIG. 27 is a partial cross-sectional and cutaway view of a
divider element of the current invention;
[0054] FIG. 28 is a plan top view of a double-sided rack system
embodiment of the animal isolation and caging system of the present
invention;
[0055] FIG. 29. a plan side view of a double-sided rack system
embodiment of the animal isolation and caging system of the present
invention;
[0056] FIG. 30a is a plan side view of a single-sided rack system
of the cage level barrier cage constructed in accordance with the
present invention;
[0057] FIG. 30b is a front view of a single-sided rack system of
the cage level barrier cage constructed in accordance with the
present invention;
[0058] FIG. 30c is a front view of a single-sided rack system of
the cage level barrier cage constructed in accordance with the
present invention;
[0059] FIG. 31 is a plan side view of a cage locking system for
securing the cages of the current invention to a double-sided rack
system of the animal isolation and caging system constructed in
accordance with the present invention;
[0060] FIG. 32 is a plan front view of a cage locking system for
securing the cages of the current invention to a double-sided rack
system of the animal isolation and caging system constructed in
accordance with the present invention;
[0061] FIG. 33 is a plan top view of a double-sided rack system of
the animal isolation and caging system constructed in accordance
with the present invention;
[0062] FIG. 34 is a side view of a cage locking system for securing
the cages of the current invention to a single-sided rack system of
the animal isolation and caging system constructed in accordance
with the present invention;
[0063] FIG. 35 is a front view of a cage locking system for
securing the cages of the current invention to a single-sided rack
system of the animal isolation and caging system constructed in
accordance with the present invention;
[0064] FIG. 36 is a plan top view of a cage locking system for
securing the cages of the current invention to a single-sided rack
system of the animal isolation and caging system constructed in
accordance with the present invention;
[0065] FIG. 37 is a plan top view of a double-sided rack system of
the animal isolation and caging system constructed in accordance
with the present invention indicating the emphasis on the use of
see through materials for enhanced visual observation of the caging
system and animals held therein;
[0066] FIG. 38 is a plan side view a double-sided rack system of
the animal isolation and caging system constructed in accordance
with the present invention indicating the emphasis on the use of
see through materials for enhanced visual observation of the caging
system and animals held therein;
[0067] FIG. 39 is a plan front view of a double-sided rack system
of the animal isolation and caging system constructed in accordance
with the present invention indicating the emphasis on the use of
see through materials for enhanced visual observation of the caging
system and animals held therein;
[0068] FIG. 40 is a front view of a cage body and diet delivery
system of the current animal isolation and caging system indicating
the emphasis on the use of see through materials;
[0069] FIG. 41 is a top view of a cage body and diet delivery
system of the current animal isolation and caging system indicating
the emphasis on the use of see through materials, without the
presence of a filter cap to enclose the interior of the cage
body;
[0070] FIG. 42 is a side view a cage body and diet delivery system
of the current animal isolation and caging system indicating the
emphasis on the use of see through materials, without the presence
of a filter cap to enclose the interior of the cage body;
[0071] FIG. 43 is a perspective view of a cage body and diet
delivery system of the current animal isolation and caging system
indicating the emphasis on the use of see through materials,
without the presence of a filter cap to enclose the interior of the
cage body, also showing indents in cage body configuration for a
rear locking tab and filter top lock respectively;
[0072] FIG. 44 is a front view of a cage body and diet delivery
system of the current animal isolation and caging system indicating
the emphasis on the use of see through materials, without the
presence of a filter cap to enclose the interior of the cage body,
also showing a divider element separating a cage of the invention
into two compartments;
[0073] FIG. 45 is a plan top view of a cage body and diet delivery
system of the current animal isolation and caging system indicating
the emphasis on the use of see through materials, without the
presence of a filter cap to enclose the interior of the cage body,
also showing a divider element separating a cage of the invention
into two compartments;
[0074] FIG. 46 is a plan side view cage body and diet delivery
system of the current animal isolation and caging system indicating
the emphasis on the use of see through materials, without the
presence of a filter cap to enclose the interior of the cage body,
also showing a divider element separating a cage of the invention
into two compartments;
[0075] FIG. 47 is a perspective view of a cage body and diet
delivery system of the current animal isolation and caging system
indicating the emphasis on the use of see through materials,
without the presence of a filter cap to enclose the interior of the
cage body, also showing a divider element separating a cage of the
invention into two compartments;
[0076] FIG. 48 is a front view of a second embodiment of the cage
of the animal isolation and caging system of the invention
providing a rotatable feeding mechanism, also including the
optional presence of a diet delivery system of the current
invention;
[0077] FIG. 49 is a top view of a second embodiment of the cage of
the animal isolation and caging system of the invention providing a
rotatable feeding mechanism, also including the optional presence
of a diet delivery system of the current invention;
[0078] FIG. 50 is a side view, with a partial cutaway, of a second
embodiment of the cage of the animal isolation and caging system of
the invention providing a rotatable feeding mechanism, also
including the optional presence of a diet delivery system of the
current invention;
[0079] FIG. 51 is a perspective view of a second embodiment of the
cage of the animal isolation and caging system of the invention
providing a rotatable feeding mechanism, also including the
optional presence of a diet delivery system of the current
invention;
[0080] FIG. 52 is a front view of a filter removal device
constructed in accordance with the present invention;
[0081] FIG. 53 is a top view of a filter removal device constructed
in accordance with the present invention;
[0082] FIG. 54 is a side view of a filter removal device
constructed in accordance with the present invention;
[0083] FIG. 55 is a perspective view of a filter removal device
constructed in accordance with the present invention;
[0084] FIG. 56 is a front view of a valve charging station
constructed in accordance with the present invention;
[0085] FIG. 57 is a plan top view of a valve charging station
constructed in accordance with the present invention, including the
valve charging stations location within the cage body of the
current invention;
[0086] FIG. 58 is a side view of a valve charging station
constructed in accordance with the present invention, including the
valve charging stations location within the cage body of the
current invention;
[0087] FIG. 59 is a partial cutaway view of the canopy capture
system of the current invention including indications for the flow
of unwanted gases and contaminants from above a cage body through a
canopy capture channel into a exhaust duct;
[0088] FIG. 60 is a side view of a canopy element for the rack of
the animal isolation and caging system of the invention;
[0089] FIG. 61 is a perspective view a canopy for the rack of the
animal isolation and caging system of the invention, including
attachment elements for connection to a ventilated rack system of
the invention;
[0090] FIG. 62 is a front view of a canopy element for the rack of
the animal isolation and caging system of the invention;
[0091] FIG. 63 is a top view of a canopy element for the rack of
the animal isolation and caging system of the invention;
[0092] FIG. 64 is a cross-sectional view of a canopy capture
channel constructed in accordance with the present invention;
[0093] FIG. 65 is a top view of a canopy capture channel
constructed in accordance with the present invention;
[0094] FIG. 66 is a front view of a canopy capture channel
constructed in accordance with the present invention; and
[0095] FIG. 67 is a perspective view of a canopy capture channel
constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0096] Cage Body
[0097] Reference is first made to FIGS. 1-8, wherein a single cage
of an animal isolation and caging system, generally indicated at
10, constructed in accordance with the invention is shown. The cage
assembly incorporates a filter retainer 15, a filter frame 20, a
filter top lock 25, a chew shield 30, a plurality of snap rivets
35, a water bottle 40, a bottle cap 45, a sipper tube 50, a diet
delivery system 55, a plurality of diet delivery components 60, and
a cage body 65. Cage body 65 comprises a box-like animal cage with
a combination diet delivery system 55 capable of providing both
food and water to animals within cage 10. A reusable filter 70 is
also generally provided with caging system 10 sandwiched between
filter retainer 15 and filter frame 20.
[0098] Cage body 65 is formed with integral side walls 80, a bottom
wall or floor 82 and a open top end. The walls are preferably
formed of a clear transparent plastic such as polycarbonate, which
is rigid, durable, permits observation of animals, has a high
impact strength, and is machine washable or autoclavable at
temperatures under 250 degrees Fahrenheit. Such a cage is
conventional, commercially available, and widely used. A standard
absorbent flooring of particulate matter such as wood chips (not
shown) may be spread on floor 82 of cage body 65. The open top of
cage body 65 is bordered by peripheral lip 83 which extends
continuously therearound. Cage body 65 may also include a plurality
of corner structural reinforcements 84 for added structural support
for cage 10. When included in a rack system 100 cage 10 may include
a cage coupling valve 75 designed to attach cage 10 integrally into
rack system 100 and provide water and air for animals located in an
individual cage 10.
[0099] Referring now to FIGS. 21-27, another embodiment of the
current invention provides for the placement of a removable divider
element 105 whose peripheral edge 106 is contoured to the cage
system 10 and will prevent any caged animals from gaining purchase
on divider element 105 and chewing through it or otherwise damaging
it. Each of the compartments 105a and 105b formed as a result of
the removable divider element 105 being provided with individual
food and water sources in the form of a plurality of diet delivery
components 60. Specifically referring to FIGS. 24-27, it can be
seen that divider element 105 is precisely contoured and molded to
fit into cage body 65 and cage system 10 (not shown) without
disturbing the integrity of the "petri dish" configuration between
filter cap 11 and cage body 65 to form an enclosed caging system 10
capable of housing at least one animal in each of compartments 105a
and 105b. Divider element 105 is configured so as to accept the
placement of at least two diet delivery systems 55 (not shown) in
divider grooves 104. Though divider element 105 may be constructed
of any suitable material it is preferably formed out of opaque
plastic material, the material chosen is rigid, durable, permits
observation of animals, has a high impact strength, and is machine
washable or autoclavable at temperatures under 250 degrees
Fahrenheit.
[0100] Divider element 105, when placed in cage body 65 has
peripheral edge 106 in flush contact with floor 82 and at least two
opposing side-walls 80 (see FIGS. 21 and 23) and upper edge 14 that
will be in contact with the undersurface of filter cap 11 when cage
assembly 10 is closed. Divider element 105 has divider lips 107
that are contoured to fit within indents 108 in cage body 65 when
divider 105 is positioned along the line indicated by arrow D in
FIG. 25 from the front to rear of cage assembly 10 such that the
integrity of the "petri dish" configuration between filter cap 11
and cage body 65 to form an enclosed caging system 10 is not
altered. Though cage body 65 may be have a variety of dimensions
provided to house individual laboratory animals in compliance with
the provisions of the Animal Welfare Act ("AWA")(enacted in 1966)
and the Institute of Laboratory Animal Resources ("ILAR")
Guidelines (1996) specify certain space parameters for specific
animal species and for animals at specific developmental stages or
weights. ANIMAL WELFARE ACT 9 C.F.R. .sctn..sctn. Chapter 1 et seq.
(1966), and as amended 7 U.S.C. .sctn..sctn. 2131 et seq.; and see,
GUIDE FOR THE CARE AND USE OF LABORATORY ANIMALS, Institute of
Laboratory Animal Resources (ILAR); National Academy Press
Washington, D.C. (1996)(both incorporated herein by reference), the
use of divider element 105 cage body 65 would be divided into
compartments 105a and 105b each of sufficient size to house a
variety of animals also in compliance with AWA and ILAR. In one
embodiment of cage assembly 10 the dimensions of cage body 65 would
be sufficient to provide a footprint of at least 140 square inches,
preferably 140.8 square inches. This footprint is sufficient to
house to large rats within the confines of a cage assembly 10 with
or without divider 105. Rack system 100 may be configured such that
80 cages providing 140.8 square inches of floor space each may be
provided in a double-sided rack system and 36 cages of a similar
dimension in a single-sided rack system. It should be remembered
that the mobile rack systems envisioned by the invention are
dimensioned so as to be movable through the typical and well known
dimensions of doors in terms of width and height. Mobile rack
systems are also capable of continuously providing air and water to
cages placed within and attached to the rack systems 100. It is
also envisioned that other animals, including mice, would be housed
within the confines of cage assembly 10 with any needed changes to
cage size or dimension, including changes to divider grooves 104 or
peripheral edge 106 to conform to changes in cage dimensions.
[0101] Referring now to FIGS. 9-12, the current invention provides
for the use of a diet delivery system 55 for providing food and
needed liquids to laboratory animals in cage assembly 10. Diet
delivery system 55 is composed of a water bottle 40 that typically
contains water for animals consumption but may be used to provide
liquids other than pure water, and diet delivery components 60.
Components 60 may be utilized to provide solid food to animals
within cage assembly 10. Diet delivery system 55, bottle 40, and
components 60 may be composed of any material or combination of
materials, typically plastics with some machined metal features
such as a metal wire food holder element 61 or bottle holder
element 62. Diet delivery system 55 has flanges 63 that fit within
cage body grooves 64 to securely hold diet delivery system within
cage body 65 and above the floor 82 (not shown) so that food and
water are accessible to animals within cage 10. Cage body grooves
64 are contoured such that when flanges 63 of diet delivery system
55 are placed therein filter cap 11 of cage assembly 10 can be
easily closed and sealed with filter top lock 25 (not shown).
[0102] In alternate embodiment according to the invention diet
delivery system 55 and bottle 40 may be made of clear plastic such
that observation of animals in cage assembly 10 is optimized. In
this instance holder elements 61 and 62 may still be composed of
machined metal but in this embodiment the machined metal portions
of holder elements 61 and 62 are reduced to the lower portions of
components 60 with the upper body 66 of components 60 made of clear
or non-metallic material.
[0103] Referring now to FIGS. 31-47, another embodiment of cage
assembly 10 and rack system 100 is construction of a cage assembly
10 and rack system 100 that emphasizes the use of clear materials
that would allow an operator to more easily determine the condition
of individual animals and the environment in individual cages. In
this embodiment the plastics utilized by a manufacturer to produce
cage assembly 10 and rack system 100 would be clear, not opaque,
and metallic components would be limited as possible, including
chew shield 30 and cage coupling 75. Moreover, rack system 100
would utilize high impact plastics materials in air supply plena
110, air exhaust plena 120, and open rack 115.
[0104] Rack System
[0105] Referring now to FIGS. 28-39, an animal isolation and caging
rack system 100 of the invention includes an open rack 115 having a
left side wall 125 and a right side wall 130, a plurality of rack
coupling stations 16, a top 135, and a bottom 140. A plurality of
posts 145 are disposed in parallel between top 135 and bottom 140.
Vertical posts 145 are preferably narrow and may comprise walls
extending substantially from the front of rack 115 to the rear of
rack 115, or may each comprise two vertical members, one at or near
the front of rack 115 and the other at or near the rear of rack
115. Rack system, in accordance with the embodiments of the current
invention, may be a one-sided rack system with regard to cage
assemblies placed therein as seen in FIGS. 30a-c and 34-36 or
two-sided as seen in FIGS. 31-33 and 37-39.
[0106] Animal isolation and caging rack system 100 also includes a
plurality of air supply plena 110 and air exhaust plena 120
alternately disposed in parallel between left side wall 125 and
right side wall 130 in rack 115. Air is forced into air supply
plena 110 by at least one control unit 150 through an air supply
conduit 151, said air supply conduit 151 communicating with each
air supply plenum 110 through a side wall of the rack 115. A
control unit 150 preferably communicates with a blower 155 (not
shown) and at least one rack air filter 158 for supplying filtered
air to rack 115 and a plurality of cage level barrier cage
assemblies 10. Air is withdrawn from air exhaust plena 120 by a
vacuum 160 through air exhaust conduit 165, said air exhaust
conduit 165 communicating with each air exhaust plenum 120 through
a side wall of the rack 115. A plurality of cage level barrier
cages (cages 10) may be positioned within rack 115. Each cage is
formed of a gas impermeable floor 82 having an upstanding sidewall
80 and a filter cap 11.
[0107] Now referring to FIGS. 13-16 and 59-67, a plurality of cage
assemblies 10 are positioned within rack 115 by canopies generally
indicated at 170. Each canopy 170 shrouds a cage assembly 10a below
a canopy 170. Accordingly, each canopy 170 is shaped and positioned
so as to come into substantial contact with peripheral lip 83 which
extends from the upper wall 23 of filter retainer 15 from a cage
assembly 10a. Accordingly, with the substantial contact between lip
83 and a canopy 170 there is the creation of an exhaust zone 175
above filter cap 11 of cage assembly 10a. Unwanted gasses and
contaminants including allergens, dander, dust and ammonia moving
into exhaust zone 175 from cage assembly 10a are moved from exhaust
zone 175 through exhaust channel 95 across canopy capture element
90 forming a canopy capture channel "C" into an exhaust duct 165 or
exhaust duct 165a. This movement is initiated through the creation
of a negative pressure in exhaust zone 175 by a vacuum 160 (not
shown). The placement of a cage assembly 10a in rack 115 causes an
engagement between the upper surface of filter cap 11 and canopy
capture element 90. This exhaust of contaminants or unwanted gasses
protects animals in each of the cage assemblies 10 present in a
rack 115 through the individual venting of exhaust zone 175 and
also protects operators utilizing the animal isolation and caging
system of the invention from exposure to allergens or other
contaminants.
[0108] Canopy capture element 90 maintains a short gap h between
the top 23 of filter cap 11 and canopies 170. Gap h should be
sufficient to allow movement of gases between canopy 170 and filter
cap 11, and in an exemplary embodiment gap h is {fraction (1/16)}
of an inch to 1/4 of an inch. Canopy 170 profiles filter cap 23 and
overlaps overhangs lateral peripheral flange 88 of filter cap 11,
preferably creating a tension fit against the sidewall 80 of cage
body 65. The rear of canopy capture element 90 is attached to air
exhaust duct 165 or air exhaust plenum 120.
[0109] Canopies 170 are disposed in parallel columns in rack 115
between each pair of adjacent posts 145, or between left side wall
125 and an adjacent post 145, or between right side wall 130 and an
adjacent post 145. Each canopy 170 supports a first cage 10a above
the canopy 170 in the rack 115 and shrouds the filter cap 11 of a
second cage 10b below the canopy 170 in the rack forming a exhaust
zone 175 with peripheral lip 83. The floor 82 of a cage assembly 10
of the first cage 10a rests on top of the corresponding canopy 170.
Of course, those canopies positioned at the top row of rack 115 do
not support a cage assembly 10 above them, and those cages 10
positioned on the bottom row of rack 115 are preferably supported
by bottom 116 of rack 115. When positioned in the rack, each cage
assembly 10 communicates with air supply plenum 120 through a cage
coupling 75. Such cage couplings 75 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 plena 120 may also
include means for delivering a supply of water to cage assemblies
10 through cage coupling 75, as is also known in the art. Canopies
170 are preferably constructed of a lightweight, transparent
material which is substantially rigid, such as clear plastic. Such
clear plastic canopies provide enhanced visibility of cage
assemblies 10 within rack system 100 and reduce the overall weight
of rack system 100.
[0110] Referring in particular to FIG. 28, a cage 10 is positioned
within rack 115 and coupled to an air supply plenum 110a through
cage coupling 75. Blower 155 forces air into the air supply plenum
110a in the direction of arrow A, and air is consequently forced
into cage 10 through cage coupling 75 in the direction of arrow B
to supply air to animals within the cage assembly 10. Vacuum 160
withdraws air from air exhaust plenum 120 through canopy capture
channel C into exhaust channel 95, thereby creating a negative
pressure within the exhaust zone 175. Ducts 166 are formed in air
exhaust plena 120 below the position at which canopy 170 is
attached and communicating with gap h, permitting air in exhaust
zone 175 to be drawn into air exhaust plena 120 causing a negative
pressure within the space defined by peripheral lip 83 and canopy
170.
[0111] Referring to FIGS. 60-63, a first embodiment of canopy 170,
generally indicated at 170a, comprises a top plate 171. Top plate
171 is attached to canopy capture element 90 and is in
communication rack 115 (not shown) at an air exhaust plenum 120
(not shown). Top plate 171 has canopy capture sidewalls 172 which
extend below the filter frame outer edge 33 of filter cap 11.
Sidewalls 172 are disposed so as to extend underneath at least a
portion of the overhang of outer edge 33 and filter cap 11.
[0112] Canopy 170a is preferably mounted to air plenum 120 at the
rear and to two posts 145 at the front of rack 115. Each post 145
preferably comprises a vertical T-beam, with a first face 145a
being disposed substantially parallel to the direction of insertion
of a cage assembly 10 into rack 115, and a second face 145b being
disposed substantially perpendicular to said direction of
insertion. Each side of face 145b is provided with notches 145c for
supporting canopy 170a therein. To maximize horizontal cage density
within rack 115, notches 145a preferably extend as close to face
145a as possible, and face 145a of post 145 is preferably made as
narrow as possible while still providing structural support for
rack 115. By providing such a notched T-beam post 145 on each side
of canopy 170a, canopy 170a may be supported on both sides from the
front of rack 115. Other means of providing the support of posts
145 are contemplated by the invention. For example, a notched
L-beam post 145 could be used, thereby providing support to only
one side of canopy 170a from the front of the rack, or canopies
170a could be screwed to a flat vertical panel disposed parallel
the cage insertion direction and extending from the top to the
bottom of rack 115.
[0113] Accordingly, because each canopy 170 acts as both a support
for the cage assembly 10 above it in rack 115 as well as a shroud
over the filter cap of the cage 10 below it in rack 115 which
guides exhaust air into exhaust conduit 165 from the cage 10 as
well as ambient air into the air exhaust plenum 120, additional
shelving is not needed to position and support cages 10 within rack
115. As a result, cages 10 may be vertically positioned closer
together in rack 115 than in a rack having distinct shelving,
thereby advantageously increasing the stacking density of cages 10
within rack 115.
[0114] Now referring to FIGS. 56-58, an embodiment of the current
invention includes a valve charging station 400 connected to rack
system 100 through a air conduit 401. Charging station 400 provides
for the consistent movement of pressurized air for the cage
assemblies 10 of an open rack 115, through a plurality of air
supply plena 110. Air moves through nozzle assembly 402. Charging
station 400 may also be located integral to a rack system 100.
[0115] Filter Cap
[0116] Reference is now made to FIGS. 13-16, in which a filter cap,
generally indicated at 11, for an open-top cage, such as cage 10
described above, and fitting within rack system 100 constructed in
accordance with the invention is shown. Filter cap 11 is configured
to cover the top of a cage floor 82 (not shown). Filter retainer 15
has a top ridge 85 which extends substantially around the top of
filter retainer 15, having an exhaust channel 95 moving in the
direction of Arrow D, for canopy capture element 90 to remove
unwanted gases and contaminants from the cage 10 when cage 10 is
incorporated in rack system 100 (not shown). Cage floor 82 may also
include corner structural reinforcements 84 for added structural
support and for stacking a plurality of cages bottoms (not
shown).
[0117] Filter cap 11 may be formed as a layered construction
including a filter retainer 15, a reusable filter 70, a filter
frame 20, a chew shield 30 of layered construction 11 held together
to filter frame 20 by a plurality of snap rivets 35. Snap rivets 35
may be constructed of many materials but must be durable,
preferably snap rivets 35 are constructed of nylon or metal. Filter
retainer 15 is preferably formed of clear plastic which is
substantially rigid but permits a modest degree of flexure when
torsional forces are applied thereto. As shown in FIGS. 13-16,
filter retainer 15 has a perforated top wall 21 which is integrally
molded with a top ridge 85 extending substantially around the top
of filter cap 11. Top wall 21 is provided with a plurality of
perforations 23, preferably of generally square configuration and
forming a grid array. Respective opposed pairs of filter side walls
24 depend substantially orthogonally from top wall 21. The surface
formed on filter retainer 15 for resting filter cap 11 on cage
floor 82 includes a continuous lateral peripheral flange 88
extending generally perpendicularly outwardly from side walls 24.
Lateral flange 88 serves to encompass and detachably secure to
filter frame 20. Ribs 91 extend from flange 88 to allow stacking of
the filter retainer 15.
[0118] Referring to FIGS. 1 and 13-16, Filter cap 11 is also
provided with a filter frame 20. Filter frame 20 is preferably
formed of material having the same properties as those of filter
retainer 15 described above but with a different rigidity. Filter
frame 20 detachably and securely maintains an air filter 70 (not
shown) to the undersurface of top wall 21. Filter frame 20 includes
a generally flat perforated top wall 31. Top wall 31 includes a
substantially rectangular body portion 32. An outer flange 33 of
body portion 32 depends from filter frame 20. A continuous
peripheral flange 34 depends from outer peripheral flange 33.
[0119] In FIG. 16, flange 33 is spaced from, encompasses and
overhangs lip 83 of cage body 65 (not shown). Thus, filter cap 11
cannot be inadvertently dislodged from cage body 65 and must be
lifted off to be removed. It should also be noted that the
clearance space between flange 33 and lip 83 should permit only a
slight movement of filter cap 11 on cage body 65. However, outer
flange 33 is preferably of sufficient lateral extent to remain in
contact with lip 83 despite any relative lateral movement between
filter cap 11 and cage body 65, thereby maintaining the integrity
of the "petri dish" configuration between filter cap 11 and cage
body 65 to form an enclosed caging system 10 capable of housing at
least one animal.
[0120] To prevent animals placed within cage assembly 10 from
damaging the cage or any of filter cap 11's components the current
invention provides chew shield 30 integrally connected to the
underside of filter frame 20 by the use of a plurality of snap
rivets 35. Chew shield 30 is designed to allow the passage of air
and other gasses but to prevent any animals from within cage 10
from gaining purchase on other components of the filter cap 11.
Chew shield 30 is preferably constructed of metal and extends into
the upper area of cage body 65 inside sidewalls 80 to reduce any
lateral movement of filter cap 11 relative to cage body 65.
[0121] In a preferred embodiment, air filter 70 is a thin sheet of
spun-bonded polyester of the type sold by DuPont under the
trademark REEMAY 2024. A filter thickness of between 10 and 15
millimeters has been found adequate for a filter having an area
approximately equivalent to the area of filter retainer top wall
21. Air filter 70 is mounted on the top surface of filter frame 20
and is held in place by filter retainer 15 in a manner to be now
described. REEMAY 2024 is used by way of example only and any
filter medium having at least its properties or similar properties
may be utilized.
[0122] Filter cap 11, air filter 70 is placed against the top wall
31 of filter frame 20 of filter cap 11. Thereafter, filter retainer
15 is mounted atop filter frame 20. Top wall 31 of filter frame 20
is provided with perforations 34 which are preferably substantially
coextensive and in alignment with perforations 23 in top wall 21 of
filter retainer 15 when filter frame 15 is mounted atop filter
frame 20. The mesh structure of top wall 31 serves to prevent air
filter 70 from sagging and holds air filter 70, while filter frame
20 holds filter 70 securely in place against the top surface of top
wall 21. In the assembled filter cap 11, perforated top wall 21
overlies filter 70 to protect the filter 70 against damage during
handling and prevent its movement or buckling, while filter 70
rests flush upon perforated top wall 31 of filter frame 20 which
supports and protects air filter 70 in its mounted position.
Additionally, touching the filter 70 with fingers may destroy the
filter integrity, and therefore the perforated walls 21 or 31
respectively on either side of the filter 70 prevent contact with
the filter by the technician during handling and also prevents
contact with the filter by the animal. The lower region of filter
cap 11 is further protected from animal damage by the use of chew
shield 30. Chew shield 30 being attached to filter frame 20 through
the use of a plurality of snap rivets 35 (not shown).
[0123] Filter retainer 15 is held in place by means of small
projections or detents 51 which are integrally molded on the outer
surface of filter frame body 32. Four spaced detents 51 are molded
on each long side filter frame body 32 of filter cap 11, and two
spaced detents 51 are molded on each shorter filter frame body 32.
Each of the detents 51 has a convex or arcuate free end. Similarly,
apertures or slots 52 are formed in filter frame body 32 of filter
frame 20 which are positioned and dimensioned so as to snugly
receive detents 51 when filter retainer 15 is mounted on filter cap
11. In an alternative embodiment, detents 51 could be formed on the
inner surface of filter frame body 32 of filter frame 20, while
slots 52 would be formed in side walls 53 of filter cap 11. It is
also possible to dimension filter retainer 15 to be held to filter
frame 20 by a tension fit.
[0124] Detents 51 are precisely molded on filter frame 20 and are
spaced from the top surface of peripheral flange 88 by a distance
slightly greater than the height of integral peripheral flange 88
of the filter frame 20. After air filter 70 has been positioned
against the bottom surface of top wall 21, filter retainer 15 is
moved downwardly upon filter frame 20 toward the perforated top
wall 21 thereof to permit detents 51 to engage slots 52. Filter
frame body 32 of filter frame 20 flex outwardly to the mounted
position. At the same time, the meshed structure of perforated top
wall 31 of filter frame 20 engages the lower surface of air filter
70 and presses filter 70 firmly against the lower surface of top
wall 21 of filter retainer 15. Air filter 70 is thus sandwiched
between filter retainer 15 and the top surface of top wall 32 of
filter frame 20, and may be retained in this mounted position by
the engagement of detents 51 with filter retainer 15.
[0125] Filter retainer 15, filter frame 20 and air filter 70 may
thus be firmly locked in a mounted position so that they cannot be
accidentally dislodged during autoclaving or handling. An assembled
filter cap 11 can thus be lifted and removed from cage body 65 for
all normal functions such as feeding, treating or examining animals
therein without disturbing or dislodging air filter 70.
[0126] Filter Removal Device
[0127] Referring to FIGS. 52-55, when it becomes necessary to
replace or remove filter 70 from filter cap 11, another of
embodiment of the current invention provides a filter removal
device 200, constructed in accordance with the invention is shown.
Filter removal device 200 includes a base board 201, and a first
guide support 205 and a second guide support 210 mounted thereon in
facing relationship. A respective separator 202, 203 is mounted on
an outer surface of a respective guide support 204, 206.
[0128] Base board 201 is formed with left slots 215 and right slots
220. A plurality of screws 225 (of which one is shown) extend
through a respective one of slots 215, 220 or 221 and affix guide
support 205 and guide support 210 to base board 201. Slots 215 and
slots 220 extend for a length along the width of base board 201 to
allows screw 225 to slide within slots 215, 220 to adjust the
position of guide supports 205, 210 relative to each other. In a
preferred embodiment, each of slots 215, 220 and 221 has a length
of 1/8 of an inch allowing each guide support 205 and guide support
210 to be moved towards the other or away from the other by 1/8 of
an inch to accommodate a variety of filter caps 11 and cage bodies
65. Mounting holes 226 may be formed within base board 201 to mount
base board 201 at a desired location of a work bench, table or the
like. In a preferred embodiment, base board 201 is formed of
bakelite.
[0129] Guide supports 205 and 210 are substantially L-shaped when
viewed on end and have a side wall 227 and 228 respectively. A
slide surface 230 is formed at the top of side walls 227 and 228.
An inner guide surface 229 extends substantially orthogonally from
slide surface 230 to provide a corner along the length of guide
support 205. Similarly, guide support 205 has a side wall 227, a
slide surface 230 and an inner guide surface 229.
[0130] A separator 231 includes a top 232 and a tapered surface 233
extending towards top 232 to form a substantially rectangular front
end 234 of separator 231. Separator 231 is affixed to side wall 227
by screws 199 at a position in which top 232 is substantially
co-planar with slide surface 230. Separator 231 is affixed in a
similar manner. Guide supports 205, 210 define a slide path for a
cage top from which a filter retainer is to be separated. Guide
supports 204, 205 are positioned so as to define a distance
therebetween substantially equal to the width of the filter
retainer. In a preferred embodiment, support guides 205, 210 are
made of plastic while separators 231, are made of machined
aluminum.
[0131] During operation, a filter cap is placed on guide support
205 and guide support 210 in an inverted position so that the
filter cap 11 is in facing relationship with base board 201 (not
shown). The skirt of the cage top rests on slide surfaces 230, 240.
The cage top is slid along slide surfaces 230, 240 in the direction
of arrow B towards the separating edge 241 of separators 231, 242.
Because the skirt slides along slide surface 230, 240 and because
separators 231, 242 are substantially coplanar with slide surface
230, 240 separator edge 241 is substantially disposed at the
position where the filter retainer meets the cage top, acting as a
wedge to separate the filter retainer from the cage top as the cage
top is slid along the cage top slide path. Once a complete pass has
been made by the cage top, the filter retainer will fall to the
surface of base board 201 allowing for easy removal of the filter
which had been previously retained between the filter retainer and
cage top.
[0132] In providing a filter frame for an open-top cage with a
perforated filter retainer which snaps onto a similarly perforated
filter frame, a filter cap for an animal cage top provides a filter
that may be easily and quickly changed. By providing the filter
above the perforated top wall of the filter frame, the filter may
be replaced while the filter frame is on the cage to ensure that
animals within the cage are not permitted to escape while the
filter is being replaced. In addition, the substantially rigid chew
shield attached to the underside of the filter frame protects the
filter cap from damage caused by animals within the cage. Moreover,
by securing the filter retainer to the filter frame and thusly to
the chew shield with an integrally formed attachment means, such as
tabs and slots, no special tools are necessary to remove the filter
retainer or for replacing the filter.
[0133] Cage Dimension
[0134] Reference is now made to FIGS. 3 and 14, in which a
particular configuration of an animal cage is shown which serves to
maximize the number of animals which may be maintained in a cage
rack system of a given size. Each cage is required to provide a
predetermined square area per animal contained in the cage. It is
possible to increase the area within the cage by extending the
length of the cage, the depth of the cage. By providing increasing
the bottom area by extending the cage, it is possible to increase
the number of animals within the cage without increasing the
associated width or height so that rack and canopy systems as
described above can accommodate both the conventional cage and the
new larger cage. Preferably, the cage assembly 10 of the current
invention has a square area of at least 140 square inches and is
capable of supporting two large rats while remaining in compliance
with the ILAR and AWA regulations. Most preferably, the cage
assembly 10 of the current invention has a square area of 140.8
square inches.
[0135] Filter Cap Top Lock
[0136] Reference is now made to FIGS. 13-14 and 17-20, wherein a
locking mechanism, generally indicated at 25, constructed in
accordance with the present invention to secure a variety of sized
cages is depicted. Locking mechanism 25 locks a cage assembly 10
and includes a base member 250 a releasable latching member 251.
Latching member 251 is integrally attached to base member 250 and
when securing a filter cap 11 to a cage body 65 is disposed in a
locking position such that foot 252 and shoulder member 254 of
latching member 251 are in close locking contact with the lower
surface of filter cap 11 and peripheral lip 83 (not shown). Filter
lock 25 provides a secure seal for cage assembly 10 through tension
from foot 252 and the lower surface of filter cap 11 and peripheral
lip 83. This tension can be easily released by an operator by
pushing in a downward direction on latching member 251. By further
providing a locking mechanism with a base member which is easily
detachable by an operator between a locking and unlocked position,
a simple mechanism is provided which easily and quickly allows
secure locking and unlocking of a cage within a rack system with a
minimum of effort and a minimum number of parts. In addition, by
providing a locking mechanism which is mounted to a post of a rack
system accessible from the front of the rack system, a readily
visible locking mechanism is provided which allows an operator to
easily determine whether a cage is properly secured within the rack
system.
[0137] Rotatable Feeder
[0138] Now referring to FIGS. 48-51, a second embodiment of cage
assembly 10 employing a rotable multiple dosage feeder 300 for a
cage body 65 is also provided. The rotatable multiple dosage feeder
300 includes a frame 301 having a cage-interior side, a food
holding member 302 rotatably mounted on the frame 301, and a food
presentation member 303 disposed on the cage-interior side of the
frame 301. The food holding member 302 holds a plurality of
measured dosages of food or other substances, and at least a
portion of the food holding member 302 extends to the cage-interior
side of the frame 301. The food presentation member 303 permits
access to a single dosage of the plurality of dosages by an animal
within the cage 10. At least a portion of the food holding member
302 is rotatable within the food presentation member so as to
expose the single dosage of the plurality of dosages, while the
food presentation member 303 prevents access to any remaining
dosages on the cage-interior side of the frame 301. With carousel
feeder the floor area is 124 sq. inches excluding carousel.
[0139] It will thus be seen that the objects set forth above, among
those made apparent from the preceding description, are efficiently
attained and, since certain changes may be made in the above
construction without departing from the spirit and scope of the
invention, it is intended that all matter contained in the above
description or shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
[0140] 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.
* * * * *