WO2002011523A1

WO2002011523A1 - Cage for breeding experimental animals and individually ventilated apparatus for cage rack system

Info

Publication number: WO2002011523A1
Application number: PCT/KR2001/001319
Authority: WO
Inventors: Jae-Jin Jang
Original assignee: Bio Genomics, Inc.
Priority date: 2000-08-03
Filing date: 2001-08-03
Publication date: 2002-02-14
Also published as: TW536381B; AU2001275824A1

Abstract

Disclosed herein is a cage for breeding experimental animals and individually ventilated system for a cage rack system. In the experimental animal cage, a feed bottle and a water bottle can be airtightly and demountably mounted on the cage, so experimental animals are prevented from being infected with various bacteria and the like and dying in a laboratory other than a clean room. In the individually ventilated system, the cage rack system is provided with air supply and exhaust units, so aseptic air can be supplied to a plurality of cages in a forced circulation way.

Description

CAGE FOR BREEDING EXPERIMENTAL ANIMALS AND INDIVIDUALLY VENTILATED APPARATUS FOR CAGE RACK SYSTEM

Technical Field

The present invention relates generally to a cage for breeding experimental animals and individually ventilated apparatus for a cage rack system, and more particularly to a cage for breeding experimental animals in which a feed bottle and a water bottle can be airtightly and demountably mounted on the cage so as to prevent experimental animals from being infected with various bacteria and airborne contaminants and dying in a laboratory other than a clean room, and an individually ventilated system in which the cage rack system is provided with air

^supply and exhaust units so as to supply aseptic air to a plurality of cages in a forced circulation way.

Background Art

In general, while new medicines are developed, validity experiments are indispensably performed to confirm the effect and toxicity of the new medicine in advance. In this case, in order to learn the clinical side effects of the medicines on human beings in advance, animal experiments are performed. For an experimental animal, there is used a mouse that has high fertility.

Mice models must have reliability in experiments when animal experiments are performed in not only large-scale facilities with clean rooms but also the laboratories of universities and small-to-medium-sized enterprises without clean rooms.

That is, in long-term carcinogenicity study or toxicity study experiments, experimental animals should be prevented from dying due to infection from the outside. Additionally, while various kinds of animals, such as a group of germfree animals and gnotobiotic animals, are bred together in the same room,

SPF animals are bred in a clean room, or general animals are bred in a SPF breeding room, animals should be prevented from exerting bad effects on surroundings and being infected from surroundings.

A conventional experimental animal breeding cage having such a use is comprised of a box-shaped container formed of transparent polycarbonate, a stainless steel wire cover having a lattice structure to support a water bottle and to allow feed to be passed through, and a cage lid formed of transparent material to seal the container. Five to six mice are bred in a single conventional cage generally.

As a result, the cage lid is always opened whenever feed is supplied and water bottle are replaced, so there occurs a problem that animals in the conventional trial animal breeding cage may be infected through the openings formed in the latticed wire cover.

In order to prevent infection, there is necessitated a structure that is capable of supplying feed, water and fresh air into a sealed housing from the outside of the sealed housing.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and a first object of the present invention is to provide a cage for breeding experimental animals, in which a feed bottle and a water bottle can be airtightly and demountably mounted on the cage, thereby preventing experimental animals from being infected with various bacteria and airborne contaminants and dying in a laboratory without a clean room, simplifying the structure of the cage and improving the airtightness of the cage.

A second object of the present invention is to provide an individually ventilated apparatus for a cage rack system, in which the cage rack system is provided with air supply and exhaust units so that aseptic air can be supplied to a plurality of cages in a forced circulation way, thereby preventing experimental animals from being infected with various bacteria and the like and dying in a laboratory without a clean room. In order to accomplish the first object, the present invention provides a cage for breeding experimental animals, comprising: a sealed housing comprised of a container having a predetermined interior space required to breed experimental animals and a cage lid detachably attached to the container and provided on one side with a depressed receiving portion; a water bottle comprised of a water bottle body for containing water, a first nozzle for discharging water contained in the water bottle body by sucking, and a connecting member tightly attached to a lower end of the water bottle body and provided with an insertion hole for the first nozzle for connecting the water bottle body to the first nozzle to suck water while airtightness is maintained; a feed bottle comprised of a feed bottle body for containing feed and a second nozzle provided with a plurality of feed discharge holes for discharging feed contained in the feed bottle body in the form of particles, the second nozzle being detachably attached through the cage lid from the outside; inlet and outlet airtight connecting means mounted on the cage lid for airtightly supporting the first nozzle of the water bottle and the second nozzle of the feed canister; first air circulation means for supplying fresh air to an interior of the housing through an air inlet unit, sucking contaminated air in the housing through an air outlet unit, removing contaminants from air, exhausting air to the outside; and second air circulation means for circulating fresh air through the interior of the housing.

The cage further comprises a protector fixedly attached to a lower surface of the depressed receiving portion so as to prevent a lower portion of the depressed receiving portion, in which the water bottle and the feed bottle are accommodated, from being damaged by experimental animals contained in the container. The air inlet unit comprises: a first bracket fitted into a through hole formed on one side of the container and provided on its center portion with a center hole; a second bracket provided on its center portion with a center hole and airtightly interlocked with the first bracket to be fixedly attached to the container while being sealed; a moving member elastically supported in the depressed portion of the first bracket and provided with a plurality of air inlets; and a sealing plate attached to the moving member by a nut through a stem passing through the center hole of the moving member.

The air exhaust unit includes an outlet filter, the outlet filter being comprised of a fixing member fitted into a through hole formed on one side of the container and provided with a fixing projection, a filter container lid provided through it with a plurality of outlet holes and on its circumferential surface with a plurality of connecting slits, a low density filter for filtering large-sized contaminants, and a filter container provided on a circumferential surface of its front portion with connecting projections to be interlocked with the connecting slits of the filter container lid and on a circumferential surface of its rear portion with a fixing recess to be interlocked with the fixing projection of the fixing member and on connecting projections.

The sealing plate is provided on its peripheral portion with a plurality of holes so as to reduce the flow speed of air supplied into the housing through the air supply nozzle and uniformly distribute the air. The second air circulation means comprises: a first circular plate attached to a lower end of the cylindrical portion formed through a through hole of the cage lid and provided with vent holes for preventing experimental animals from approaching a filter; a filter placed on an upper surface of the first circular plate for filtering contaminants included in air circulated through an interior of the cage and its outside; a rotating plate rotatably interlocked with locking pieces projected along a through hole formed on the cage lid to secure the filter and provided with a plurality of vent holes; a sealing ring disposed between the fixed piece and the rotating plate to maintain sealing; and an openable cap detachably attached to an upper end of the cylindrical body so as to prevent contaminated air from entering an interior of the cage.

The cage further comprises a label holder attached to the cage lid, the label holder comprising a holder body for holding a label on which data, such as a name of experimental animals, dates of experiments, etc., are recorded and a holder strip extended from a rear of the holder body and detachable attached to a front of the cage lid.

In the cage for breeding experimental animals of the present invention, the feed bottle and water bottle can be airtightly mounted on the cage, fresh air can be automatically supplied into the cage when the cage is mounted on the cage rack system, and the air inlet and outlet units of the cage can be kept airtight and aseptic air can be circulated in the cage when the cage is not mounted on the cage rack system. Accordingly, while the cage is isolated from the outside, the supply of feed and water can be simply performed without opening the cage lid. Accordingly, while feed and water is supplied to the cage, contaminated air leaks from the cage.

Additionally, the productivity of cage production can be improved by the simplification of the structure of the cage, and, at the same time, the airtightness of the cage can be maintained by the airtight structure of the cage that can prevent outside contaminants from entering the interior of the cage.

Accordingly, experimental animals are prevented from dying due to infection in a laboratory other than a clean room, and the light weight and lost costs of the cage can be achieved, and the cage can be conveyed without infection.

In order to accomplish the second object, the present invention provides an individually ventilated apparatus for cage rack systems holding a plurality of experimental animal cages, comprising: air supply means for forcibly supplying inlet air to the cages after filtering the air while controlling a pressure of the air to maintain a predetermined inlet air pressure; an air supply tube line extending from the air supply means to the cages and forming a passage for guiding the inlet air from the air supply means to the cages; air exhaust means for forcibly exhausting contaminated air from the cages to the outside of the cages; an air exhaust tube line extending from the cages to the air exhaust means and forming a passage for guiding the contaminated air from the cages to the air exhaust means during an operation of the air exhaust means; and an inlet air filtering means and an outlet air filtering means for filtering the inlet air sucked by the air supply means and filtering the contaminated air exhausted by the air exhaust means, respectively.

In the, individually ventilated apparatus the air supply means comprises: a housing supported on a cage rack while being vibration-isolated from the rack, with an airflow rate control unit provided at a top of the housing, the interior of the housing being partitioned into first and second chambers by a partition wall, an air supply duct provided at a side wall of the housing for supplying the inlet air from the first chamber to the cages, and a first checking cover removably mounted to the housing by a plurality of locking members at a position corresponding to the first chamber to close the first chamber while accomplishing sealing effect; an air suction fan installed within the first chamber and generating suction force for supplying the inlet air to the cages through the air supply duct; and an air supply control unit installed within the second chamber and controlling the air suction fan, and informing a user of a requirement to replace the inlet air filtering means with a new one.

The inlet air filtering means comprises: a pre-fϊlter detachably mounted to a filter bracket and primarily filtering the inlet air to remove large-sized impurities from the inlet air sucked into the first chamber through the airflow rate control unit by the suction force of the air suction fan; and a HEPA-filter communicating with the end of the air suction fan and secondarily filtering the primarily filtered inlet air to remove small-sized impurities from the inlet air, thus supplying fresh, clean and aseptic air free from impurities to the cages through the air supply tube line.

The air suction fan is supported by a vibration isolating supporter at its bottom portion, with one end of the air suction fan connected to a connection flange detachably mounted to a locking member of a support bracket, the connection flange allowing a replacement of a HEPA-filter of the inlet air filtering means with a new one.

The air supply control unit comprises: a power switch for driving the air suction fan when it is electrically activated; a pressure gauge for displaying air pressures measured by pressure nozzles respectively arranged in front and back of a HEPA-filter, and allowing a user to set an effective reference air pressure; a filter check lamp for informing the user of a requirement to replace the existing filter with a new one in response to a signal from the pressure gauge; an air pressure check lamp positioned at a right side of the filter check lamp and informing the user of an abnormal air pressure when a sensed pressure of air sucked by the air suction fan is lower than the preset reference pressure; a power check lamp for informing the user of an abnormal operational condition of the air supply means in the case of an application of exceedingly high voltage to the air supply means; an air pressure control switch for allowing the user to control the pressure of air for the animals within the cages in response to the air pressures displayed on the pressure gauge or an operation of the air pressure check lamp; and a power brake switch for allowing the user to control the operation of the air suction fan when the user recognizes an abnormal operation of the air supply means from the power check lamp.

The air supply tube line comprises: a vertical air supply tube communicating with one side of the housing of the air supply means and being downwardly extended to reach a lower end of each rack; a plurality of vertical air supply tubes, first side ends of which communicating with the vertical air supply tube and second side ends of which are closed, the vertical air supply tubes being longitudinally extended to be vertically spaced apart from each other; and a plurality of air supply nozzles, first side ends of which each communicate with each of the horizontal air exhaust tubes and second side ends of which each communicate with each of the outlets of the cages, for supplying air supplied through the vertical air supply tube and the horizontal air supply tubes to an interior of the cage. The air exhaust means comprises: a housing supported on the cage rack at a position opposite to the air supply means while being vibration-isolated from the rack, with the interior of the housing partitioned into third and fourth chambers by a partition wall, an air inlet port provided at a side wall of the third chamber for introducing the contaminated air from the cages into the third chamber, an air exhaust duct discharging the contaminated air from the third chamber to the outside, and a second checking cover removably mounted to the housing by a plurality of locking members at a position corresponding to the third chamber to close the third chamber while accomplishing sealing effect; an air exhaust fan installed within the third chamber and generating suction force for discharging the air from the third chamber to the outside through the air exhaust duct; and an air exhaust control unit installed within the fourth chamber and controlling the air exhaust fan, and informing a user of a requirement to replace the outlet air filtering means with a new one.

In an embodiment of this invention, the outlet air control unit comprises: a pre-filter and a HEPA-filter sequentially arranged inside the housing at a position close to the air inlet port and primarily filtering the contaminated air, introduced from the cages into the third chamber through both the air exhaust tube line and the air inlet port by the suction force of the air suction force and laden with CO₂ gas and ammonia gas generated from the respiration or the excrement of the animals, thus removing odor and large-sized impurities from the contaminated air; and a carbon filter secondarily filtering the primarily filtered air prior to exhausting the air from the third chamber to the outside through the air exhaust duct.

In addition, the air exhaust fan generates a suction force for forcibly discharging the contaminated air from the cages to the outside through the air exhaust duct, the air exhaust fan being supported by a vibration isolating supporter at its bottom portion, with one end of the air exhaust fan connected to a connection flange detachably mounted to a support bracket, the connection flange allowing a replacement of a carbon filter of the outlet filtering means with a new one.

The air exhaust control unit comprises: a delay timer for allowing the air exhaust fan to be operated at a time interval after the start of an air suction fan when a power switch of the air supply means is turned on, thus allowing the air exhaust means to initially discharge the contaminated air from the cages to the outside at a time interval from the start of the air suction fan; a pressure gauge for displaying air pressures measured by pressure nozzles respectively arranged in front and back of a hepa-filter of the outlet air filtering means and allowing a user to set an effective reference air pressure; a filter check lamp for informing the user of a requirement to replace the existing filter with a new one in response to a signal from the pressure gauge; an air pressure check lamp positioned at a right side of the filter check lamp and informing the user of an abnormal air pressure when a sensed pressure of air sucked by the air exhaust fan is lower than the preset reference pressure; a power check lamp for informing the user of an abnormal operational condition of the air exhaust means in the case of an application of exceedingly high voltage to the air exhaust means; an air pressure control switch for allowing the user to control the pressure of air discharged from the cages in response to the air pressures displayed on the pressure gauge or an operation of the air pressure check lamp; and a power brake switch for allowing the user to control the operation of the air exhaust fan when the user recognizes an abnormal operation of the air exhaust means from the power check lamp.

The air exhaust tube line comprises: a vertical air exhaust tube communicating with one side of the housing of the air exhaust means and being downwardly extended to reach a lower end of each rack; a plurality of vertical air exhaust tubes, first side ends of which communicating with the vertical air exhaust tube and second side ends of which are closed, the vertical air exhaust tubes being longitudinally extended to be vertically spaced apart from each other; and a plurality of air exhaust nozzles, first side ends of which each communicate with each of the horizontal air exhaust tubes and second side ends of which each communicate with each of the outlets of the cages, for exhausting contaminated air to the outside by an operation of the air exhaust fan.

As described above, the air conditioning apparatus for the cage rack systems of the present invention includes an air supply means and an air exhaust means. The air supply means always forcibly supplies fresh, clean and aseptic air to the animals within the cages while maintaining a desired air pressure. The air exhaust means discharges contaminated air from the cages to the atmosphere. The air conditioning apparatus thus accomplishes a forcible air circulation for the cages held on a rack system, thus almost completely preventing experimental animals from getting diseased or dying due to the contaminated air. This apparatus also maintains a desired agreeable environment of such cages.

In addition, a user is allowed to easily recognize the air pressures, sensed by two pressure nozzles, from a pressure gauge, thus timely replacing the existing filters with new ones and always supplying fresh, clean and aseptic air to the experimental animals within the cages. Brief Description of the Drawings

Fig. 1 is a schematic perspective view showing a cage rack system for holding multiple cages for breeding experimental animals in accordance with the present invention; Fig. 2 is an enlarged perspective view showing one of the experimental animal breeding cages in accordance with the present invention;

Fig. 3 is a partially exploded perspective view showing the experimental animal breeding cage of Fig. 2;

Fig. 4 is a front view showing the cage shown in Fig. 2; Fig. 5 is a side view showing the cage shown in Fig. 2;

Figs. 6a and 6b are a sectional view showing a water bottle connecting structure for the water bottle of the cage shown in Fig. 2 and a bottom view showing the water bottle connecting structure for the water bottle of the cage shown in Fig. 2, respectively; Fig. 7 is a sectional view showing a feed bottle connecting structure for the feed bottle of the cage shown in Fig. 2;

Figs. 8a and 8b are a side view showing the feed bottle shown in Fig. 7 and a bottom view showing the feed bottle shown in Fig. 7, respectively;

Figs. 8c and 8d are a side view showing the nozzle of the feed bottle shown in Fig. 7 and a bottom view showing the nozzle of the feed bottle shown in

Fig. 7, respectively;

Fig. 9 is a sectional view showing the air circulation unit of the cage shown in Fig. 2;

Fig. 10 is a plan view showing cylindrical member; Fig. 11 is a plan view showing the rotating plate of the ventilation unit shown in Fig. 9;

Fig. 12a is a section view taken along line X-X; Fig. 12b is a front view of a moving member;

Fig. 12c is a perspective view of an air outlet unit showing the installation of a cage exhaust filter; Fig. 12d is an exploded perspective view of the air outlet unit; Fig. 13 is a perspective view showing the passage of air in the cage; Fig. 14 is a front view showing a label holder;

Fig. 15a is a schematic perspective view showing the air conditioning apparatus for the cage rack system mounted on the cage rack system;

Fig. 15b is a schematic front view showing the for the cage rack system; Figs. 16a to 16c are a front view, a plan view and a side view of an air supply means included in the individually ventilated apparatus for the experimental animal cage rack systems in accordance with the present invention; Fig. 17 is a front view of the air supply means' housing, from which a checking cover and air filters are removed;

Fig. 18 is a side view of a checking cover detachably attached to each of the air supply means and an air exhaust means included in the individually ventilated apparatus of the present invention; Figs. 19a to 19c are a front view, a plan view and a side view of an air exhaust means included in the individually ventilated apparatus for the experimental animal cage rack systems in accordance with the present invention, respectively; and

Fig. 20 is a front view of the housing of the air exhaust means with a checking cover and air filters removed.

Best Mode for Carrying Out the Invention

First embodiment: cage for breeding experimental animals

Hereinafter, a cage for breeding experimental animals in accordance with a preferred embodiment of the present invention is described in detail with reference to accompanying drawings.

Fig. 1 is a schematic perspective view showing a cage rack system for holding multiple cages for breeding experimental animals in accordance with the present invention. Fig. 2 is an enlarged perspective view showing one of the experimental animal breeding cages in accordance with the present invention. Fig. 3 is a partially exploded perspective view showing the experimental animal breeding cage of Fig. 2.

Referring to Figs. 1 and 2, in the experimental animal breeding cage 1 of the present invention, five or six experimental animals, for example, mice, are bred together. The experimental animal breeding cage 1 is utilized while being disposed in a cage rack system 10 that is capable of accommodating a plurality of the experimental animal breeding cages 1. However, the experimental animal breeding cage 1 can be utilized alone, while not being disposed in the cage rack system 10.

The cage rack system 10 is comprised of an air supply means 11 for sucking fresh air from the outside, filtering contaminants out of the air and supplying the filtered air to the cage 1, a vertical air supply tube 12 communicating with the outlet of the air supply means 11, a plurality of horizontal air supply tubes 13 communicating with the vertical air supply tube 12, a plurality of air supply nozzles 14 the one-side ends of which each communicate with each of the horizontal air supply tubes 13 and the other-side ends of which each communicate with each of the inlets 6 of the cages 1, an air exhaust means or a return fan box 18 for exhausting the contaminated air in the cages 1 to the outside, a vertical air exhaust tube 17 communicating with the air exhaust means, a plurality of horizontal air exhaust tubes 16 communicating with the vertical air exhaust tube 17, a plurality of air exhaust nozzles 15 one side ends of which each communicate with each of the horizontal air exhaust tubes 16 and the other-side ends of which each communicate with each of the outlets 7 of the cages 1, and a frame 19 for both detachably supporting a plurality of cages 1 at preset positions and supporting the air supply means 11, the air exhaust means 18, the horizontal air supply tubes 13 and the horizontal air exhaust tubes 16.

Accordingly, when the experimental animal breeding cage 1 of the present invention is mounted on the cage rack system 10 and air-conditioned in a forced air circulation method, aseptic, fresh air is supplied by the air supply means 11 through each of the air supply nozzles 14 to the cage 1 and contaminated air is exhausted by the return fan box 18 through each of the air exhaust nozzle 15 from the cage 1.

However, as described below, the experimental animal breeding cage 1 of the present invention can be separately utilized without being mounted on the cage rack system 10.

The experimental animal breeding cage 1 of the present invention is formed of polycarbonate, stainless steel, silicon or the like, which can be sterilized by autoclave, has high durability and high chemical resistance and is harmless. The cage 1 is comprised of a box-shaped container 2, and a cage lid 3 that is engaged with the top of the container 2 to form a sealed housing 20 and to which the nozzles of a feed canister 4 and a water canister 5 are airtightly inserted into the interior of the container 2 through a depressed receiving portion 21.

A ventilation unit 8 is formed on the cage lid 3 of the cage 1 so that when the cage 1 is separately utilized, filtered air can be supplied into the interior of the cage 1 while an air inlet unit 6 and an air outlet unit 7 are closed.

Hereinafter, the detailed construction of the cage 1 of the present invention is described in detail with reference to Figs. 4 to 14.

Fig. 4 is a front view showing the cage shown in Fig. 2. Fig. 5 is a side view showing the cage shown in Fig. 2. Figs. 6a and 6b are a sectional view showing a water bottle connecting structure for the water bottle of the cage shown in Fig. 2 and a bottom view showing the water bottle connecting structure for the water bottle of the cage shown in Fig. 2, respectively. Fig. 7 is a sectional view showing a feed bottle connecting structure for the feed bottle of the cage shown in

Fig. 2. Figs. 8a and 8b are a side view showing the feed bottle shown in Fig. 7 and a bottom view showing the feed bottle shown in Fig. 7, respectively. Figs. 8c and 8d are a side view showing the nozzle of the feed bottle shown in Fig. 7 and a bottom view showing the nozzle of the feed bottle shown in Fig. 7, respectively.

Fig. 9 is a sectional view showing the air circulation unit of the cage shown in Fig.

2. Fig. 10 is a plan view showing cylindrical member shown in Fig 9. Fig. 11 is a plan view showing the rotating plate of the ventilation unit shown in Fig. 9.

Fig. 12a is a section view taken along line X-X. Fig. 12b is a front view of a moving member. Fig. 12c is a perspective view of an air outlet unit showing the installation of a cage exhaust filter. Fig. 12d is an exploded perspective view of the air outlet unit. Fig. 13 is a perspective view showing the passage of air in the cage. Fig. 14 is a front view showing a label holder. Referring to Figs. 4 and 5, a pair of locking units 22a and 22b are attached to both sides of the cage lid 3 so as to prevent the cage lid 3 from being easily separated from the container 2 after the cage lid 3 is airtightly engaged with the container 2. An O-ring 23 is fitted into a groove formed on the bottom surface of the peripheral portion of the cage lid 3 so as to allow the cage lid 3 to be airtightly engaged with the container 2.

In the locking units 22a and 22b, the upper ends of the locking units 22a and 22b are hingedly attached to the peripheral edge of the cage lid 3, and the locking members 22c and 22d of the locking units 22a and 22b inwardly projected from the handles of the locking units 22a and 22b are engaged with the fixing protrusions 2a and 2b.

A protector 3a formed of stainless steel is fixedly attached to the lower surface of the depressed receiving portion 21 so as to prevent the lower portion of the depressed receiving portion 21, in which the water bottle 5 and the feed canister 4 are accommodated, from being damaged by experimental animals contained in the container 2.

A pair of positioning brackets 19a are attached to a pair of opposite frames 19 (refer to Fig. 1), and a pair of positioning guides 24a and 24b are formed on both sides of the container 2 to be interlocked with the positioning brackets 19a. As a result, when the cage 1 is pushed into the frame 19, the positioning guides 24a and 24b are interlocked with the positioning brackets 19a, thereby securing the position of the cage 1.

As a result, the air inlet unit 6 formed on the rear of the cage 1, as shown in Figs. 12a an 12b, is airtightly interlocked with the air supply nozzle 14, and the sealing plates 91 of the air inlet unit 6 is elastically separated from the container 2 of the cage 1, thereby allowing the air supply and exhaust nozzles 14 and 15 to communicate with the interior of the cage 1 through the inlet 95 of a moving member 97 (will be described).

In the air inlet unit 6, a first bracket 93, in the depressed portion of which a center hole 93 a is formed, is airtightly interlocked with a second bracket 96, in which a center hole is formed, through the through hole formed in the container 2. The first and second brackets 93 and 96 are fixedly attached to the container 2 while being sealed.

A moving member 97, partially inserted into the center hole 93a while being supported by an elastic spring 94 and provided with a plurality of air inlets 95 is elastically supported in the depressed portion of the first bracket 93. In such a case, a sealing plate 91 is attached to the moving member 97 by a nut 98 through a stem 91b passing through the center hole 95a of the moving member 97.

In such a case, the sealing plate 91 is provided with a plurality of holes

91a through the peripheral portion of the sealing plate 91, so air supplied from the air supply nozzle 14 has a low flow speed and is widely distributed, thereby eliminating stress that may be exerted on experimental animals when the air is directly forced onto the experimental animals.

As a result, in a normal state in which the cage 1 is not joined with the cage rack system 10, the sealing plate 91 is brought into tight contact with the moving member 97 by the elasticity of the elastic spring 94, thereby sealing the cage 1 from the outside by isolating the cage 1 from the outside.

However, when the cage 1 is mounted on the cage rack system 10, the elastic spring 94 is compressed by the pushing of the air supply nozzle 14. Accordingly, the moving member 97 is brought into contact with the depressed portion of the first bracket 93 and, simultaneously, the sealing plate 91 is moved into the interior of the container 2, thereby breaking sealing. As a result, the air supply nozzle 14 communicates with the interior of the cage 1 through a plurality of air inlet holes 95 formed on the moving member 97, so air is supplied into the interior of the cage 1. Additionally, the air outlet unit 7 formed on the rear of the cage 1 is airtightly interlocked with the air exhaust nozzle 15, so the air supply and exhaust nozzles 14 and 15 communicate with the interior of the cage 1 to exhaust the air in the cage 1 through the inlet holes 102 of an inlet lid 101.

The air outlet unit 7 includes an outlet filter 100. The outlet filter 100, as shown in Figs. 12c and 12d, is comprised of a fixing member 104 fitted into a through hole formed on one side of the container 2 and provided with a fixing projection 105, a filter container lid 101 provided through it with a plurality of outlet holes 102 and on its circumferential surface with a plurality of connecting slits 103, a low density filter 106 for filtering large-sized contaminants, and a filter container 108 provided on the circumferential surface of its front portion with connecting projections 109 to be interlocked with the connecting slits 103 of the filter container lid 101 and on the circumferential surface of its rear portion with a fixing recess 107 to be interlocked with the fixing projection 105 of the fixing member 104 and on connecting projections.

Fresh air enters the interior of the cage 1 through the air inlet unit 6 connected to the air supply nozzle 14, is circulated through the interior of the cage

1, and is exhausted through the air outlet unit 7 connected to the air exhaust nozzle 15.

As described above, since the air outlet unit 7 includes the outlet filter 100, large-sized particles, such as dust from straw that are spread to provide comfort to experimental animals and to reduce stress caused by the excrements of the experimental animals or fur removed from the experimental animals, can be filtered by the low density filter 106. Accordingly, there can be prevented problems that exhausted impurities stop the air exhaust nozzle 15 and are stacked in the horizontal exhaust tube 16 and the vertical exhaust tube 17. In such a case, when the air inlet and outlet units 6 and 7 are diagonally positioned to maximize the distance between them, fresh air supplied from the air inlet unit 6 is uniformly circulated through the interior of the cage 1 as indicated in Fig. 13 and, thereafter, is discharged to the outside through the outlet 7, thereby allowing all experimental animals to desirably breathe fresh air. In the meantime, Figs. 6a and 6b are a sectional view showing the water bottle connecting structure and a bottom view showing the water bottle connecting structure. As depicted in the drawings, the water bottle 5 is comprised of a water bottle body 51 provided on its outer surface with scales indicating the amount of remaining water, a sealing member 52 tightly fitted into the opening 51a of the water canister body 51 and provided with an insertion hole 52a longitudinally passing through the sealing member 52, and a water bottle nozzle 53 tightly fitted into the insertion hole 52a of the sealing member 52 to allow water contained in the water bottle body 51 to be discharged through the water bottle nozzle 53.

The water bottle nozzle 53 is airtightly and detachably fitted into a first airtight connecting unit 50. To this end, the first airtight connecting unit 50 is comprised of a bush 57 formed of rubber, provided with a through hole 57a airtightly receiving the water bottle nozzle 53 and provided with a receiving groove on its circumferential surface, a third bracket member 54 fitted on its inner peripheral portion into the ring member receiving groove of the guide bush 57, twice bent on its middle portion to be zigzaged and tightly fitted on its bent portion 54a into the through hole 4a of the cage lid 3 and brought on its outer peripheral portion into tight contact with the lower surface of the cage lid 3, a fourth bracket member 55 provided with a center hole and tightly fitted on perpendicularly bent outer peripheral portion 55a into a depressed portion formed on the bent portion 54a of the third bracket member 54 from the inside of the cage, a fifth bracket 56 provided on its center with a through hole, tightly fitted on a perpendicularly bent inner peripheral portion 56a into a space between the bent portion 54a of the third bracket member 54 and the through hole 4a of the cage lid 3 and brought on its outer peripheral portion into contact with the upper surface of the cage lid 3, and a sealing cap 59 closing the through hole 57a into which the water bottle nozzle 53 is fitted in such a way that a hinge shaft support bracket 58 is secured to the third bracket member 54 and an extension part 56c is elastically brought into contact with the lower end of the guide bush 57.

The fourth and fifth bracket members 55 and 56 serve as wedges, so the third bracket member 54 supports the guide bush 57 and is fixedly and airtightly attached to the cage lid 3. Additionally, the through hole of the guide bush 57 is sealed by the sealing cap 59, thereby forming an entirely sealed structure. Further, when the sealing cap 59 is opened, the fourth bracket member 55 functions as a protector for preventing the guide bush 57 from being damaged by experimental animals.

As a result, when the water bottle 5 is fitted into the first airtight connecting unit 50, the water bottle nozzle 53 is airtightly fitted into the through hole 57a of the guide bush 57 of the first airtight connection unit 50 and, simultaneously, the lower end of the water bottle nozzle 53 pushes the sealing cap 59 and is lowered down. Accordingly, experimental animals contained in the cage 1 can bring their mouths to the water bottle nozzle 53 and suck water from the water bottle nozzle 53.

Additionally, the water bottle nozzle 53 is connected to the water bottle body 51 by the sealing member 52, so the space between the water bottle nozzle 53 and the water bottle body 51 is airtight, thereby preventing water from leaking through the water bottle nozzle 53 while experimental animals do not drink water. Meanwhile, Fig. 7 is a sectional view showing a feed bottle connecting structure. As depicted in the drawing, the feed bottle 4 is comprised of a cylindrical body 61 formed of transparent polycarbonate, open on its top and bottom to supply feed, and provided with a plurality of locking holes 64 oppositely situated on the peripheral edge of the lower end of the cylindrical body 61, a feed bottle lid 63 for selectively opening or closing the top of the cylindrical body and isolating the interior of the cylindrical body 61 from the outside when joined with the cylindrical body 61 to prevent experimental animals and feed from being contaminated, a base 66 formed of stainless steel, and provided on its circumferential surface with a plurality of locking projections 65 to be interlocked with the locking holes 64 when the locking projections 65 are inserted into the locking holes 64 and rotated, and a feed canister nozzle 62 comprised of a plurality of half rings 67 semispherically shaped and downwardly projected to form a plurality of feed discharge holes 62a.

The feed discharge holes 62a are formed to be smaller than a particle of feed so as to prevent feed from being easily discharged from the feed bottle 4 to the interior of the cage 1. In addition, the feed bottle nozzle 62 is detachably and airtightly fitted into a second airtight connecting unit 60 formed in the depressed receiving portion 21. The second airtight connecting unit 60 is comprised of a guide bush 57 airtightly interlocked with the depressed receiving portion 21 and provided with a through hole 57a, and a first bracket member 59b bent twice to be inclined, attached to the depressed receiving portion 21 and provided with an opening 59a.

The first bracket member 59b is formed of stainless steel to prevent the guide bush 57 formed of silicon from being damaged.

The feed bottle lid 63 is tightly joined with the cylindrical body 61. Accordingly, when the feed bottle 4 is fitted into the second connecting unit 60, the feed bottle nozzle 62 is tightly fitted into the through hole 57a of the guide bush 57 of the second airtight connecting unit 60 and lowered into the interior of the cage 1. Accordingly, experimental animals contained in the cage 1 can eat feed projected through the feed discharge holes 62a. In this case, when the size of a particle of feed is smaller than each of the holes 62a, feed falls into the interior of the cage 1 and experimental animals can eat the feed.

Additionally, in the cage 1 of the present invention, the cage lid 3, as shown in Fig. 9, is provided with the air circulation unit 8. The air circulation unit 8 is used to supply filtered, fresh air to the interior of the cage 1 in the case where the cage 1 is conveyed while containing experimental animals or separately utilized without being mounted on the cage rack system 10.

To this end, the air circulation unit 8 is fitted into the cylindrical portion 3 c that is vertically extended to form a through hole 3b. A fixed plate 81 is attached to the lower end of the cylindrical portion 3 c on which a plurality of vent holes 81 a are formed along a plurality of concentric circles to prevent experimental animals from approaching a filter 82.

Additionally, a rotating plate 83, which is detachably locked through two notches 3e between a pair of locking pieces 3d symmetrically projected along the wall of the through hole 3b formed on the cage lid 3, is positioned on the upper of the fixed plate 81 as shown in Fig. 9 and 10.

In such a case, the rotating plate 83, as depicted in Figs. 9 and 11, is provided through it with a plurality of vent slits 83a and symmetrically at its circumferential edge with locking projections 83b to correspond to the notches 3e. In this case, the rotating plate 83 is secured in such a way that the locking projections 83b are passed through the notches 3e and, thereafter, handles 83c projected from the rotating plate 83 are rotated to position the locking projections

83b under the locking pieces 3d, thereby rotating the rotating plate 83 at a predetermined angle and securing the filter 82.

An openable cap 85 is detachably attached to the upper end of the cylindrical body 3 c so as to prevent contaminated air from entering the interior of the cage 1 is carried. When the openable cap 85 is attached to the cylindrical body 3c, a sealing ring 84 is disposed between the locking pieces 3d and the rotating plate 83 to guarantee airtightness.

As a result, the ventilation unit 8 can supply fresh air to the interior of the cage 1 when the cage is carried and separately used without being mounted on the cage rack system 10, so the ventilation unit 8 can be utilized as occasion arises.

The components of the cage 1 can be formed of polysulphone, which has high strength characteristics, other than polycarbonate.

Additionally, the cage 1 can be generally employed for the use of breeding mice, but can be applied to the uses of breeding rats and rabbits by increasing the size of the cage 1 according to the size of an experimental animal.

Meanwhile, as show in Fig. 14, a label holder 200 is attached to the front of the cage lid 3 to hold a label on which data, such as the name of experimental animals, the dates of experiments, etc., are recorded. The label holder 200 is comprised of a holder body 210 for holding the label on which data are recorded and a holder strip 220 extended from the rear of the holder body 210 and ringed on its upper portion. The upper end of the holder strip 220 is detachably suspended from a rail 230 formed on the circumferential surface of the cage lid 3.

In such a case, a user can record the name of an experiment performed on the experimental animals contained in the cage 1 on a label held in the label holder 200, so the user can easily learn experiments that the experimental animals undergo. Additionally, after experiments are performed on experimental animals while the cage 1 is removed from the cage rack system, a user can easily get data concerning the experimental animals.

Second embodiment: air conditioning apparatus for cage rack system

Hereinafter, the individually ventilated apparatus for a cage rack system in accordance with a preferred embodiment of the present invention is described in detail with reference to accompanying drawings.

Fig. 15a is a schematic perspective view showing the air conditioning apparatus for the cage rack system mounted on the cage rack system. Fig. 15b is a schematic front view showing the individually ventilated apparatus for the cage rack system.

With reference to Figs. 1, 2, 15a and 15b, the schematic construction of the individually ventilated apparatus of the present invention is described hereinafter.

First of all, the construction of the experimental animal breeding cage is described hereinafter. The experimental animal breeding cage 1 is comprised of a sealed housing 20 consisting of a container 2 having a predetermined interior space required to breed experimental animals and a cage lid 3 detachably attached to the container 2 and provided on one side with a depressed receiving portion, a water bottle 5 having a water bottle nozzle airtightly and detachably attached to its body for discharging water contained in the water bottle body by sucking, and a feed bottle 4 airtightly and detachably attached through the cage lid 3 for discharging feed contained in the feed bottle body. Hereinafter, the construction of the cage rack system 10, on which the individually ventilated system of the present invention is mounted, is described.

As shown in Fig. 1, the air supply unit of the cage rack system 10 is comprised of an air supply means 11 for sucking fresh air from the outside, filtering contaminants out of the air and supplying the filtered air to the cage 1, a vertical air supply tube 12 communicating with the lower portion of the air supply means 11, a plurality of horizontal air supply tubes 13 communicating with the vertical air supply tube 12, and a plurality of air supply nozzles 14 the one-side ends of which each communicate with each of the horizontal air supply tubes 13 and the other-side ends of which each communicate with each of the inlets 6 of the cages 1. The air exhaust unit of the cage rack system 10 is comprised of an air exhaust means 18 for exhausting the contaminated air in the cages 1 to the outside, a vertical air exhaust tube 17 communicating with the lower portion of the air exhaust means 18, a plurality of horizontal air exhaust tubes 16 communicating with the vertical air exhaust tube 17, and a plurality of air exhaust nozzles 15 one side ends of which each communicate with each of the horizontal air exhaust tubes

16 and the other-side ends of which each communicate with each of the outlets 7 of the cages 1.

The frame 19 of the cage rack system 10 detachably supports a plurality of cages 1 at preset positions, supports the air supply means 11, the air exhaust means 18, the horizontal air supply tubes 13 and the horizontal air exhaust tubes

16, and positions each of the cages 1 to fit the air inlet 6 and air outlet units 7 of the cage 1 into the air supply nozzle 14 and air exhaust nozzle 15 of the cage rack system 10, respectively.

Figs. 16a to 16c are a front view, a plan view and a side view of an air supply means included in the individually ventilated apparatus for the experimental animal cage rack systems in accordance with the present invention. Fig. 17 is a front view of the air supply means' housing, from which a checking cover and air filters are removed. Fig. 18 is a side view of a checking cover detachably attached to each of the air supply means and an air exhaust means included in the air conditioning apparatus of the present invention.

The construction of the air supply means will be described in detail herein below with reference to Figs. 16a, 16b, 16c, 17 and 18.

As shown in Fig. 15b, the air supply means 11 is provided at the top of the rack system 10. A plurality of rubber isolators 110 are mounted on the bottom surface of the housing 130 of the air supply means 11 as shown in Fig. 16a, and intercept operational vibration of an air suction fan 150 during an operation of the air supply means 11, thus isolating both the rack system 10 and the frame 19 from vibration.

Therefore, it is possible to prevent experimental animals in the cages 1 of the rack system 10 from being ill-affected by vibration. The air supply means 11 comprises the housing 130, of which the interior is partitioned into first and second chambers 133 and 135 by a partition wall 131, the air suction fan 150 set within the first chamber 133, two inlet air filters 152 and 155 for filtering inlet atmospheric air to purify the air, and an air supply controller for controlling the operation of the air suction fan 150. As shown in Fig. 16a, an air supply duct 137 extends from the vertical air supply tube 12 at a side of the housing 130, and supplies inlet air from the first chamber 133 to the cages 1.

The housing 130 is closed by a first removable checking cover 140 at a position corresponding to the first chamber 133. As shown in Fig. 18, a sealing material 141 is arranged on the inner surface of the checking cover's front wall along the edge, thus sealing the gap between the opening of the first chamber 133 and the checking cover 140 when the chamber 133 is fully closed by the cover 140. Two handles 145 are mounted to the front wall of the cover 140, with four elastic locking members 143 provided on the front wall of the cover 140 for removably locking the cover 140 to the housing 130.

An airflow rate control unit 139 is provided at the upper portion of the housing 130 for guiding atmospheric air into the first chamber 133 while controlling the flow rate of inlet air as desired. This control unit 139 has an air inlet hole 139a, with four height adjusting washers 139b positioned around the corners of the air inlet hole 139a as shown in Figs. 16a to 16c. A protection cover 139c is held on the housing 130 by the four washers 139b so as to cover the hole 139a. It is possible to control the flow rate of inlet air by appropriately selecting the washers 139b having desired heights.

In order to primarily filter inlet air which is sucked into the first chamber 133 through the airflow rate control unit 139 by the suction force of the air suction fan 150, a pre-filter 152 is detachably mounted to a filter bracket 151 at a position under the air inlet hole 139a as shown in Fig. 16a.

A HEPA-filter 155 is arranged at the outlet of the air suction fan 150 so as to communicate with the fan 150 and secondarily filter the air from the air suction fan 150. The primarily filtered air from the pre-filter 152 passes through the air suction fan 150, and is secondarily filtered by the HEPA-filter 155 prior to being fed to the cages 1 through the vertical air supply tube 12.

In such a case, the PRE-filter 152 removes large-sized impurities from the inlet air, while the HEPA-filter 155 removes small-sized impurities from the air, thus supplying fresh, clean and aseptic air free from impurities to the animals within the cages. Since the PRE-filter 152 is positioned in front of the HEPA- filter 155 as described above, it is possible to lengthen the life span of the expensive HEPA-filter 155.

The bottom portion of the air suction fan 150 is supported by a vibration isolating supporter 154 mounted on the inner surface of the bottom wall of the first chamber 133, with one end of the fan 150 connected to a connection flange 156 detachably mounted to a support bracket 151.

As shown in Fig. 17, two air pressure nozzles are arranged at opposite sides of the HEPA-filter 155 set in the bracket 151. That is, a first pressure nozzle 171 is provided at a position around the air suction fan 150, while a second pressure nozzle 173 is provided at a position around the air supply duct 137.

The air supply control unit 160 is set within the second chamber 135 of the housing 130 as shown in Fig. 16a. In the control unit 160, a power switch 163 is arranged at the left side of the top portion of a control panel 161 so as to electrically activate and drive the air suction fan 150. A timer 162 is arranged at the left side of the central portion of the control panel so as to count the operational time of the air suction fan 150, while a reset switch 162a is arranged at the right side of the timer 162 so as to reset the timer 162 when necessary.

A pressure gauge 168 is arranged at the lower portion of the control panel

161. This gauge 168 includes an LED display 168a displaying air pressures measured by the first and second pressure nozzles 171 and 173, a plurality of air pressure setting buttons 168b and 168c allowing a user to set an effective reference air pressure, and a plurality of function buttons 168d and 168e.

The control panel of the control unit 160 also includes a filter check lamp 164 used for informing a user of a requirement to replace an existing filter with a new one in response to a signal from the pressure gauge 168. An air pressure check lamp 165 is positioned on the control panel at the right side of the filter check lamp 164 and informs a user of an abnormal air pressure when the sensed pressure of air sucked by the air suction fan 150 is lower than a preset reference pressure. A power check lamp 166 is positioned on the control panel at the right side of the air pressure check lamp 165 and informs the user of an abnormal operational condition of the air supply means 11 due to, for example, an application of exceedingly high voltage to the air supply means.

An air pressure control switch 169 is provided on the control panel for allowing the user to control the pressure of air for the animals within the cages in response to the air pressures displayed on the LED display 168a of the gauge 168 or an operation of the air pressure check lamp 165.

A power brake switch 167 is provided on the rear wall of the housing 130 for allowing the user to control the operation of the air suction fan 150 when the user recognizes an abnormal operation of the air supply means from the power check lamp 166 as shown in Fig. 16b. Figs. 19a to 19c are a front view, a plan view and a side view of an air exhaust means included in the air conditioning apparatus for the experimental animal cage rack systems in accordance with the present invention. Fig. 20 is a front view of the housing of the air exhaust means with a checking cover and air filters removed. As shown in Fig. 16a, the air exhaust means 18 is operated along with the air supply control unit 160 when the power switch for the air suction fan 150 is turned on. In such a case, the air exhaust means 18 discharges air, contaminated due to the respiration and excretion of animals, from the cages 1 to the atmosphere through the vertical air exhaust tube 17 and the horizontal air exhaust tubes 16. As shown in Fig. 19a, the air exhaust means 18 comprises a housing 530 which is partitioned into two chambers by a partition wall 531 in the same manner as that described for the housing 130 of the air supply means 11. Both an air exhaust fan 550 and an air exhaust control unit 560 are set within the housing 530.

That is, the interior of the housing 530 of the air exhaust means 18 is partitioned into third and fourth chambers 533 and 535 by the partition wall 531 as shown in Figs. 19b and 20. An air inlet port 537 is provided at a sidewall of the third chamber 533 for guiding contaminated air, flowing from the air exhaust nozzles 15 communicating with the cages 1 and flowing through the horizontal air exhaust tubes 16 and the vertical air exhaust tube 17, into the third chamber 533. The contaminated air introduced into the third chamber 533 of the housing 530 through the air inlet port 537 is discharged from the chamber 533 into the atmosphere through an air exhaust duct 539.

The housing 530 of the air exhaust means is provided at the top of the rack system 10, with a plurality of rubber isolators 538 mounted on the bottom surface of the housing 530 to intercept operational vibration of the air exhaust fan 550 during an operation of the air exhaust means, thus isolating both the rack system 10 and the frame 19 from the vibration. The housing 530 is also closed by a second removable checking cover 540 at a position corresponding to the third chamber 533. As shown in Fig. 18, a sealing material 541 is arranged on the inner surface of the checking cover's front wall along the edge, thus sealing the gap between the opening of the third chamber 533 and the checking cover 540 when the chamber 533 is fully closed by the cover 540. Two handles 545 are mounted to the front wall of the cover 540, with four elastic locking members 543 provided on the front wall of the cover 540 for removably locking the cover 540 to the housing 530 as shown in Fig. 19a. In order to filter the contaminated air, introduced into the third chamber

533 through the air inlet port 537 and laden with CO gas and ammonia gas generated from the animals, prior to exhausting the air into the atmosphere, a pre- filter 552a and a hepa-filter 555 are sequentially supported by a filter bracket 551 provided inside the housing 530 at a position close to the air inlet port 537 as shown in Fig. 19b.

The air exhaust fan 550 generates a suction force for sucking the contaminated air into the third chamber 533 through the air inlet port 537. The end of the fan 550 is connected to a connection flange 558 of a support bracket 557 as shown in Fig. 19b, with a carbon filter 552b removably set in the bracket 557 and secondarily filtering the primarily filtered air from the fan 550. The above carbon filter 552b filters the contaminated air to remove ammonia gas generated from the excrement of the animals in addition to odor generated from the animals.

Thereafter, the filtered air from the carbon filter 552b passes through an air exhaust duct 539 to the atmosphere through an air exhaust port 536 provided at the rear wall of the housing 530.

In the air exhaust means, two pressure nozzles are arranged at opposite sides of the carbon filter 552b set in the bracket 551. That is, a first pressure nozzle 571 is provided at a position around the air exhaust fan 550, while a second pressure nozzle 573 is provided at a position around the air exhaust port 536. The air exhaust control unit 560 is set within the second chamber 535 of the housing 530. In the control unit 560, a delay timer 563 is arranged on a control panel 561 so as to allow the air exhaust fan 550 to be operated at a time interval after the start of the air suction fan 150 when the power switch 163 of the air supply means of Fig. 16a is turned on. Therefore, the air exhaust means starts to discharge contaminated air from the cages 1 to the atmosphere at a time interval from the start of the air suction fan 150.

A main timer 562 is arranged at the left side of the central portion of the control panel 561 so as to count the operational time of the air exhaust fan 550, while a reset switch 562a is arranged at the right side of the timer 562 so as to reset the timer 562 when necessary.

A pressure gauge 568 is arranged at the lower portion of the control panel

561. This gauge 568 includes an LED display 568a displaying air pressures measured by the first and second pressure nozzles 571 and 573, a plurality of air pressure setting buttons 568b and 568c allowing a user to set an effective reference air pressure, and a plurality of function buttons 568d and 568e.

The control panel 561 of the control unit 560 also includes a filter check lamp 564 used for informing a user of a requirement to replace an existing filter with a new one in response to a signal from the pressure gauge 568. An air pressure check lamp 565 is positioned on the control panel at the right side of the filter check lamp 564 and informs a user of an abnormal air pressure when the sensed pressure of air sucked by the air exhaust fan 550 is lower than a preset reference pressure. A power check lamp 566 is positioned on the control panel at the right side of the air pressure check lamp 565 and informs the user of an abnormal operational condition of the air exhaust means due to, for example, an application of exceedingly high voltage to the air exhaust means. An air pressure control switch 569 is provided on the control panel at the right side of the delay timer 563 for allowing the user to control the pressure of exhaust air from the cages 1 in response to the air pressures displayed on the LED display 568a of the gauge 568 or an operation of the air pressure check lamp 565.

A power brake switch 567 is provided on the rear wall of the housing 530 for allowing the user to control the operation of the air exhaust fan 550 when the user recognizes an abnormal operation of the air exhaust means from the power check lamp 566 as shown in Fig. 19b.

The operational effect of the air conditioning apparatus according to the present invention for supplying fresh, clean and aseptic air to the cages 1 of the rack system 10 and exhausting contaminated air from the cages 1 to the atmosphere will be described herein below.

As shown in Fig. 1, a plurality of cages 1 are arranged on the frame 19 of the rack system in a way such that the air inlet and air outlet of each cage 1 are connected to associated air supply nozzle 14 and air exhaust nozzle 15 of the air conditioning apparatus.

After the arrangement of the cages 1 on the rack system, the power switch

163 is turned on, and so the air suction fan 150 of the air supply means is started.

After a preset time set by the delay timer 563 provided at the air exhaust control unit 560 of the air exhaust means 18 has been elapsed from the start of the air suction fan 150, the air exhaust fan 550 of the air exhaust means is started.

During the operation of the individually ventilated apparatus, the air supply means 11 supplies air into the first chamber 133 of the housing 130 through the airflow rate control unit 139 by the suction force of the air suction fan 150 set in the chamber 133. In such a case, the pre-filter 152 primarily filters the inlet air from the airflow rate control unit 139. The primarily filtered air is, thereafter, introduced into the air supply duct

137, and passes through the connection flange 156 connected to the end of the air suction fan 150 prior to being secondarily filtered by the hepa-filter 155. The secondarily filtered air is, thereafter, is fed to the vertical air supply tube 12 through the air supply duct 137. The secondarily filtered air flows from the vertical air supply tube 12 into the horizontal air supply tubes 13 connected to the vertical air supply tube 12, and is supplied into the cages 1 through the air supply nozzles 14 provided at the horizontal air supply tubes 13. In such a case, the inlet air is primarily and secondarily filtered by the two filters 152 and 155, and so the air is almost free from impurities or bacteria.

During the supply of air into the cages 1 of the rack system using the air supply means of the air conditioning apparatus, when an exceedingly high voltage is applied to the air supply means or an operational error occurs in the air supply means, the power check lamp 166 is turned on to inform a user of the abnormal operational condition of the air supply means due to the application of exceedingly high voltage or the error. When the user recognizes the abnormal operation of the air supply means from the power check lamp 166, he operates the power brake switch 167 to stop the operation of the air suction fan 150 prior to checking the air supply means. Therefore, it is possible to almost completely prevent death of animals from suffocation due to unexpected stop of air supply for the animals within the cages 1.

In the present invention, the air supply means of the individually ventilated apparatus is preferably provided with a signal transmission means capable of transmitting an alarm message to a user's pager phone or cellular phone in place of turning on the power check lamp 166 in the case of occurrence of such an abnormal operation of the air supply means. During the operation of the air supply means, it is possible for a user to check the air pressures measured by the two air pressure nozzles 171 and 173 from the LED display 168a of the pressure gauge 168. In addition, the user can set effective reference air pressures using the air pressure setting buttons 168b and 168c.

In such a case, it is possible for the user to directly control the pressure of air for the cages 1 using the air pressure control switch 169 in accordance with the air pressures displayed on the LED display 168a of the pressure gauge 168 or an operation of the pressure check lamp 165. During the operation of the individually ventilated apparatus of the present invention, the air exhaust means forcibly discharges contaminated air from the cages to the atmosphere using the exhaust force of the air exhaust fan 550 as shown in Figs. 1, 2, 15a, 15b and 19a to 19c. Therefore, the individually ventilated apparatus of this invention accomplishes a desired forcible air circulation for the cages 1 held on the rack system.

In order to exhaust the contaminated air from the cages 1 to the atmosphere, the air exhaust fan 550 inside the housing 530 of the air exhaust means is started, thus forcing the contaminated air from the cages 1 to sequentially pass through the air exhaust nozzles 15, horizontal air exhaust tubes 16 and vertical air exhaust tube 17.

The contaminated air is, thereafter, introduced into the third chamber 533 of the housing 530 through the air inlet port 537. In such a case, the contaminated air is primarily filtered by both the pre-filter 552a and the HEPA- filter 555. Thereafter, the primarily filtered air passes through the air exhaust fan 550 and flows into the air exhaust duct 539. In such a case, the primarily filtered air laden with CO gas and ammonia gas generated from the respiration and excretion of animals is secondarily filtered by the carbon filter 552b installed at a side of the air exhaust fan 550, and so the gases are removed from the air. The air from the carbon filter 552b passes through the air exhaust duct 539 prior to being discharged from the housing 530 of the air exhaust means to the atmosphere through the air exhaust port 536 provided at the rear wall of the housing 530.

When an exceedingly high voltage is applied to the air exhaust means or an operational error occurs in the air exhaust means during an operation of the air exhaust means, the power check lamp 566 is turned on to inform a user of the abnormal operational condition of the air exhaust means due to the application of exceedingly high voltage or the error in the same manner as that described for the air supply means. When the user recognizes the abnormal operation of the air exhaust means from the power check lamp 566, he operates the power brake switch 567 to stop the operation of the air suction fan 550 prior to checking the air exhaust means. Therefore, it is possible to almost completely prevent death of animals from suffocation due to unexpected stop of air circulation within the cages 1.

During the operation of the air exhaust means, it is possible for a user to check the air pressures measured by the two air pressure nozzles 571 and 573 from the LED display 568a of the pressure gauge 568 in the same manner as that described for the air supply means. In addition, the user can set effective reference air pressures using the air pressure setting buttons 568b and 568c.

In such a case, it is possible for the user to directly control the pressure of air for the cages 1 using the air pressure control switch 569 in accordance with the air pressures displayed on the LED display 568a of the pressure gauge 568 or an operation of the pressure check lamp 565.

Industrial Applicability

As described above, the present invention provides a cage for breeding experimental animals, in which a feed bottle and a water bottle can be airtightly and demountably mounted on the cage, thereby preventing experimental animals from being infected with various bacteria and the like and dying in a laboratory without a clean room, simplifying the structure of the cage and improving the airtightness of the cage.

The individually ventilated apparatus includes an air supply means and an air exhaust means. The air supply means always forcibly supplies fresh, clean and aseptic air to the animals within the cages, while the air exhaust means discharges contaminated air from the cages to the atmosphere. That is, the air conditioning apparatus accomplishes a forcible air circulation for the cages held on the rack system, thus almost completely preventing the experimental animals from getting diseased or dying due to the contaminated air. This apparatus also maintains a desired agreeable environment of such cages.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A cage for breeding experimental animals, comprising: a sealed housing comprised of a container having a predetermined interior space required to breed experimental animals and a cage lid detachably attached to said container and provided on one side with a depressed receiving portion; a water bottle comprised of a water bottle body for containing water, a first nozzle for discharging water contained in said water bottle body by sucking, and a connecting member tightly attached to a lower end of said water bottle body and provided with an insertion hole for said first nozzle for connecting said water bottle body to said first nozzle to suck water while airtightness is maintained; a feed bottle comprised of a feed bottle body for containing feed and a second nozzle provided with a plurality of feed discharge holes for discharging feed contained in said feed bottle body in the form of particles, said second nozzle being detachably attached through said cage lid from the outside; inlet and outlet airtight connecting means mounted on said cage lid for airtightly supporting the first nozzle of said water bottle and the second nozzle of said feed bottle; first air circulation means for supplying fresh air to an interior of said housing through an air inlet unit, sucking contaminated air in said housing through an air outlet unit, removing contaminants from air, exhausting air to the outside; and second air circulation means for circulating fresh air through the interior of said housing.

2. The cage according to claim 1, further comprising a protector fixedly attached to a lower surface of said depressed receiving portion so as to prevent a lower portion of said depressed receiving portion, in which said water bottle and said feed bottle are accommodated, from being damaged by experimental animals contained in said container.

3. The cage according to claim 1, wherein said air inlet unit comprises: a first bracket fitted into a through hole formed on one side of said container and provided on its center portion with a center hole; a second bracket provided on its center portion with a center hole and airtightly interlocked with said first bracket to be fixedly attached to said container while being sealed; a moving member elastically supported in the depressed portion of said first bracket and provided with a plurality of air inlets; and a sealing plate attached to said moving member by a nut through a stem passing through the center hole of said moving member.

4. The cage according to claim 1, wherein said air exhaust unit includes an outlet filter, said outlet filter being comprised of a fixing member fitted into a through hole formed on one side of the container and provided with a fixing projection, a filter container lid provided through it with a plurality of outlet holes and on its circumferential surface with a plurality of connecting slits, a low density filter for filtering large-sized contaminants, and a filter container provided on a circumferential surface of its front portion with connecting projections to be interlocked with the connecting slits of the filter container lid and on a circumferential surface of its rear portion with a fixing recess to be interlocked with the fixing projection of the fixing member and on connecting projections.

5. The cage according to claim 3, wherein said sealing plate is provided on its peripheral portion with a plurality of holes so as to reduce the flow speed of air supplied into said housing through said air supply nozzle and uniformly distribute the air.

6. The cage according to claim 1, wherein said second air circulation means comprises: a first circular plate attached to a lower end of said cylindrical portion formed through a through hole of said cage lid and provided with vent holes for preventing experimental animals from approaching a filter; a filter placed on an upper surface of said first circular plate for filtering contaminants included in air circulated through an interior of said cage and its outside; a rotating plate rotatably interlocked with locking pieces projected along a through hole formed on said cage lid to secure said filter and provided with a plurality of vent holes; a sealing ring disposed between said fixed piece and said rotating plate to maintain sealing; and an openable cap detachably attached to an upper end of said cylindrical body so as to prevent contaminated air from entering an interior of said cage.

7. The cage according to claim 1, further comprising a label holder attached to said cage lid, said label holder comprising a holder body for holding a label on which data, such as a name of experimental animals, dates of experiments, etc., are recorded and a holder strip extended from a rear of said holder body and detachable attached to a front of said cage lid.

8. An individually ventilated apparatus for cage rack systems holding a plurality of experimental animal cages, comprising: air supply means for forcibly supplying inlet air to the cages after filtering the air while controlling a pressure of the air to maintain a predetermined inlet air pressure; an air supply tube line extending from said air supply means to said cages and forming a passage for guiding the inlet air from the air supply means to the cages; air exhaust means for forcibly exhausting contaminated air from said cages to the outside of said cages; an air exhaust tube line extending from said cages to said air exhaust means and forming a passage for guiding the contaminated air from the cages to the air exhaust means during an operation of said air exhaust means; and inlet air filtering means and outlet air filtering means for filtering the inlet air sucked by the air supply means and filtering the contaminated air exhausted by the air exhaust means, respectively.

9. The individually ventilated apparatus according to claim 8, wherein said air supply means comprises: a housing supported on a cage rack while being vibration-isolated from the rack, with an airflow rate control unit provided at a top of said housing, the interior of said housing being partitioned into first and second chambers by a partition wall, an air supply duct provided at a side wall of the housing for supplying the inlet air from the first chamber to the cages, and a first checking cover removably mounted to the housing by a plurality of locking members at a position corresponding to the first chamber to close the first chamber while accomplishing sealing effect; an air suction fan installed within the first chamber and generating suction force for supplying the inlet air to the cages through the air supply duct; and an air supply control unit installed within said second chamber and controlling the air suction fan, and informing a user of a requirement to replace the inlet air filtering means with a new one.

10. The individually ventilated apparatus according to claim 9, wherein said inlet air filtering means comprises: a PRE-filter detachably mounted to a filter bracket and primarily filtering the inlet air to remove large-sized impurities from the inlet air sucked into the first chamber through the airflow rate control unit by the suction force of the air suction fan; and a HEPA-filter communicating with the end of the air suction fan and secondarily filtering the primarily filtered inlet air to remove small-sized impurities from the inlet air, thus supplying fresh, clean and aseptic air free from impurities to the cages through the air supply tube line.

11. The individually ventilated apparatus according to claim 9, wherein said air suction fan is supported by a vibration isolating supporter at its bottom portion, with one end of said air suction fan connected to a connection flange detachably mounted to a locking member of a support bracket, the connection flange allowing a replacement of a hepa-filter of the inlet air filtering means with a new one.

12. The individually ventilated apparatus according to claim 9, wherein said air supply control unit comprises: a power switch for driving the air suction fan when it is electrically activated; a pressure gauge for displaying air pressures measured by pressure nozzles respectively arranged in front and back of a hepa-filter, and allowing a user to set an effective reference air pressure; a filter check lamp for informing the user of a requirement to replace the existing filter with a new one in response to a signal from the pressure gauge; an air pressure check lamp positioned at a right side of the filter check lamp and informing the user of an abnormal air pressure when a sensed pressure of air sucked by the air suction fan is lower than the preset reference pressure; a power check lamp for informing the user of an abnormal operational condition of the air supply means in the case of an application of exceedingly high voltage to the air supply means; an air pressure control switch for allowing the user to control the pressure of air for the animals within the cages in response to the air pressures displayed on the pressure gauge or an operation of the air pressure check lamp; and a power brake switch for allowing the user to control the operation of the air suction fan when the user recognizes an abnormal operation of the air supply means from the power check lamp.

13. The individually ventilated apparatus according to claim 8, wherein said air supply tube line comprises: a vertical air supply tube communicating with one side of the housing of said air supply means and being downwardly extended to reach a lower end of each rack; a plurality of vertical air supply tubes, first side ends of which communicating with said vertical air supply tube and second side ends of which are closed, said vertical air supply tubes being longitudinally extended to be vertically spaced apart from each other; and a plurality of air supply nozzles, first side ends of which each communicate with each of the horizontal air exhaust tubes and second side ends of which each communicate with each of the outlets of the cages, for supplying air supplied through said vertical air supply tube and said horizontal air supply tubes to an interior of said cage.

14. The individually ventilated apparatus according to claim 8, wherein said air exhaust means comprises: a housing supported on the cage rack at a position opposite to the air supply means while being vibration-isolated from the rack, with the interior of said housing partitioned into third and fourth chambers by a partition wall, an air inlet port provided at a side wall of the third chamber for introducing the contaminated air from the cages into the third chamber, an air exhaust duct discharging the contaminated air from the third chamber to the outside, and a second checking cover removably mounted to the housing by a plurality of locking members at a position corresponding to the third chamber to close the third chamber while accomplishing sealing effect; an air exhaust fan installed within the third chamber and generating suction force for discharging the air from the third chamber to the outside through the air exhaust duct; and an air exhaust control unit installed within said fourth chamber and controlling the air exhaust fan, and informing a user of a requirement to replace the outlet air filtering means with a new one.

15. The individually ventilated apparatus according to claim 8, wherein said outlet air control unit comprises: a PRE-filter and a HEPA-filter sequentially arranged inside the housing at a position close to the air inlet port and primarily filtering the contaminated air, introduced from the cages into the third chamber through both the air exhaust tube line and the air inlet port by the suction force of the air suction force and laden with CO₂ gas and ammonia gas generated from the respiration or the excrement of the animals, thus removing odor and large-sized impurities from the contaminated air; and a carbon filter secondarily filtering the primarily filtered air prior to exhausting the air from the third chamber to the outside through the air exhaust duct.

16. The individually ventilated apparatus according to claim 14, wherein said air exhaust fan generates a suction force for forcibly discharging the contaminated air from the cages to the outside through the air exhaust duct, said air exhaust fan being supported by a vibration isolating supporter at its bottom portion, with one end of said air exhaust fan connected to a connection flange detachably mounted to a support bracket, the connection flange allowing a replacement of a carbon filter of the outlet filtering means with a new one.

17. The individually ventilated apparatus according to claim 14, wherein said air exhaust control unit comprises: a delay timer for allowing the air exhaust fan to be operated at a time interval after the start of an air suction fan when a power switch of the air supply means is turned on, thus allowing the air exhaust means to initially discharge the contaminated air from the cages to the outside at a time interval from the start of the air suction fan; a pressure gauge for displaying air pressures measured by pressure nozzles respectively arranged in front and back of a HEPA-filter of the outlet air filtering means and allowing a user to set an effective reference air pressure; a filter check lamp for informing the user of a requirement to replace the existing filter with a new one in response to a signal from the pressure gauge; an air pressure check lamp positioned at a right side of the filter check lamp and informing the user of an abnormal air pressure when a sensed pressure of air sucked by the air exhaust fan is lower than the preset reference pressure; a power check lamp for informing the user of an abnormal operational condition of the air exhaust means in the case of an application of exceedingly high voltage to the air exhaust means; an air pressure control switch for allowing the user to control the pressure of air discharged from the cages in response to the air pressures displayed on the pressure gauge or an operation of the air pressure check lamp; and a power brake switch for allowing the user to control the operation of the air exhaust fan when the user recognizes an abnormal operation of the air exhaust means from the power check lamp.

18. The individually ventilated apparatus according to claim 8, wherein said air exhaust tube line comprises: a vertical air exhaust tube communicating with one side of the housing of said air exhaust means and being downwardly extended to reach a lower end of each rack; a plurality of vertical air exhaust tubes, first side ends of which communicating with said vertical air exhaust tube and second side ends of which are closed, said vertical air exhaust tubes being longitudinally extended to be vertically spaced apart from each other; and a plurality of air exhaust nozzles, first side ends of which each communicate with each of the horizontal air exhaust tubes and second side ends of which each communicate with each of the outlets of the cages, for exhausting contaminated air to the outside by an operation of said air exhaust fan.