In industries which require working in a space, isolated from the external atmosphere, i. e., a sealed confinement enclosure, it is customary to operate the input and the output of the different products and apparatus by means of containers connected to the enclosure with a double-door, sealed transfer device. The industries concerned with this technology are, in particular, the pharmaceutical, medical, food- stuffs and nuclear industries. etc.

It is known to provide isolation chambers or"clean rooms"to provide an aseptic or sterile environment for various purposes. In clean rooms, elaborate precautions are taken to reduce dust particles and other contaminants in the air. The pharmaceutical industry uses the sterile environment provided by the isolating chambers for conducting experiments and tests and for manufacturing drugs. The electronics industry uses clean rooms to manufacture various type of electrical components. Because the clean room must be kept aseptic or sterile in order for the experiments and the testing or manufacturing procedures to be effective, it is desirable to reduce the likelihood that contaminants will be transferred into the isolation chamber. Therefore, problems arise when items must be transferred from a non-sterile environment outside the isolation chamber into the isolation chamber.

A transfer port apparatus and method is disclosed in U. S. Patent No.

5,425, 400 to Szatmary, which disclosure is hereby incorporated by reference herein.

See also the disclosure in U. S. Patent Nos. 4,494, 586; 4,747, 601; 5,263, 521 ; 5, 588, 473; 5,700, 043; 5,226, 781 ; and 4,897, 963, which disclosures are also hereby incorporated by reference herein.

In accordance with the present invention, a transfer port apparatus is provided to enable material to be transferred from an isolation chamber in an isolator

to a canister chamber in a mobile canister. The transfer port apparatus includes a canister portion formed to include a canister passageway and adapted to be coupled to the canister to place the canister passageway in communication with the canister chamber formed in the canister, and an isolator portion formed to include an isolator passageway and adapted to be coupled to the isolator to place the isolator passageway in communication with the isolation chamber formed in the isolator.

A latch is arranged to couple the canister portion to the isolator portion to place the canister passageway in communication with the isolator passageway to establish a transfer conduit through the canister and isolator portions to enable material to be transferred between the canister chamber and the isolation chamber through the transfer conduit. A removable conduit closure is arranged to lie in and occlude the transfer conduit. The canister portion includes a seal support and an expansible seal member mounted on the seal support and arranged to move relative to the seal support from a contracted position to an expanded position to establish a substantially airtight sealing engagement with the removable conduit closure.

In preferred embodiments, wherein the expansible seal member includes an inner ring configured to mate with and seal against the removable conduit closure upon insertion of the removable conduit closure into the canister passageway formed in the canister portion. The transfer port apparatus further includes a pneumatic system for passing a pressurized fluid through an air conduit formed in the seal support to a fluid-receiving space provided between the seal support and the inner ring to move the inner ring away from the seal support to the expanded position against the removable conduit closure.

The removable conduit closure includes a canister door sized to close the canister passageway and the inner ring is positioned to engage an outer surface of the canister door upon movement of the expansible seal member to the expanded position to establish a substantially airtight seal therebetween. The removable conduit closure further includes an isolator door sized to close the isolator passageway and arranged to lie adjacent to the canister door when the canister portion is coupled to the isolator portion.

The transfer port apparatus further includes a valve and conduit system for retaining the pressurized fluid in the fluid-receiving space to maintain the inner ring

in the expanded position engaging the outer surface of the canister door upon decoupling of the canister portion and isolator portion while the canister door is positioned to close the canister passageway and the isolator door is positioned to close the isolator passageway. A valve is coupled to the air conduit formed in the seal support and configured to move between an opened position allowing flow of pressurized fluid into the air conduit to reach the inner ring and a closed position retaining pressurized fluid in the air conduit to maintain the inner ring in the expanded position. This system enables a user to inflate the canister seal and retain that seal in an inflated state even though the canister is uncoupled from the isolator and the pressurized fluid onboard the isolator is no longer communicated to the canister seal.

A vacuum system is provided for removing the pressurized fluid from the fluid-receiving space and applying a suction force to the inner ring in the fluid- receiving space to move the inner ring from the expanded position to the contracted position to disestablish the substantially airtight sealing engagement with the removable conduit closure. The vacuum system includes a vacuum generator and a pressure selector coupled to the vacuum generator, the pressurized fluid source, and the air conduit and configured to move between a seal-establishing position coupling only the pressurized fluid source to the air conduit and a seal-disestablishing position coupling only the vacuum generator to the air conduit.

A distribution conduit is coupled to the pressurized fluid source and a connector coupled to the distribution conduit and configured to be coupled to the air conduit upon coupling of the canister portion to the isolator portion to enable pressurized fluid to pass from the pressurized fluid source into the air conduit through the distribution conduit and the connector. The isolator portion is formed to include a portion of the distribution conduit therein.

Additional features and advantage of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of prepared embodiments exemplifying the best mode of carrying out the invention as presently perceived.

Brief Description of the Drawings The detailed description particularly refers to the accompanying figures in which: Fig. 1 is an exploded perspective view of a transfer port apparatus in accordance with the present invention showing a canister formed to include a canister chamber containing a bottle (in phantom), an isolator formed to include an isolation chamber accessible to a worker by means of two access ports, several components just outside the canister chamber that cooperate to form a canister portion of the transfer port apparatus, and several components in the isolation chamber that cooperate to form an isolator portion of the transfer port apparatus ; Fig. 2 is an exploded, perspective, assembly view of components comprising the transfer port apparatus of Fig. 1 showing (from left to right) a canister gasket, mounting fixture, canister door frame including an inflatable seal member carried on a sturdy ring-shaped seal support, canister door, isolator gasket, isolator door frame including an inflatable seal member carried on a sturdy ring-shaped seal support, and isolator door; Fig. 3A is a sectional view of the components shown in Figs. 1 and 2 after they have been assembled to form the canister and isolator portions and the canister and isolator portions have been mated to form the transfer port apparatus and showing both of the canister door and isolator door in their closed positions closing a transfer conduit providing a passageway extending horizontally through the transfer port apparatus and interconnecting the"left-side"canister chamber and the"right-side" isolation chamber and showing spring-loaded ball detents arranged to couple the isolator door to the canister door to form a removable conduit closure when both doors are mounted in their passageway-closing positions in the transfer conduit of the transfer port apparatus; Fig. 3B is a top plan view of the isolator door showing the arrangement of the spring-loaded ball detents ; Fig. 4 is a perspective view of a"loaded"canister containing a bottle and an"empty"isolator prior to mating engagement of the canister portion (appended to the canister) and the isolator portion (appended to the isolator) to establish the assembled transfer port apparatus and showing both of the canister door and the

isolator door in a closed and sealed position to maintain airtight clean working environments in the canister chamber and the isolation chamber; Fig. 5 is a side elevation view of the apparatus shown in Fig. 4 ; Fig. 6 is a perspective view similar to Fig. 4 showing coupling of the canister portion to the isolator portion to establish the transfer port apparatus; Fig. 7 is a side elevation view of the apparatus shown in Fig. 6 ; Fig. 8 is a perspective view similar to Figs. 4 and 6 showing the isolator door after it has been moved to an opened position to open a passageway formed in the isolator portion of the transfer port apparatus and expose handles on the still- closed canister door to a worker accessing the isolation chamber in the isolator through the two access ports formed in a rear side wall of the isolator ; Fig. 9 is a side elevation view of the apparatus shown in Fig. 8; Fig. 10 is a perspective view similar to Figs. 4,6, and 8 showing the canister door after it has been moved to an opened position to open a passageway formed in the canister portion of the transfer port apparatus and placed above the isolator door in a"nested"position in a cavity formed in the isolator door ; Fig. 11 is a side elevation view of the apparatus shown in Fig. 10; Fig. 12 is a side elevation view similar to Fig. 11, with portions broken away, showing movement of the bottle in the canister chamber into the isolation chamber through the sealed transfer conduit passageway formed in the transfer port apparatus and opened upon removal of the canister door and isolator door from passageway-closing positions in the canister portion and the isolator portion; Fig. 13 is a view similar to Fig. 12 showing movement of the canister door and the isolator door toward their passageway-closing positions after transfer of the bottle into the isolation chamber; Fig. 14 is a view similar to Fig. 13 showing disengagement of the canister portion from the isolator portion after reinstallation of the canister door in the canister portion and the isolator door in the isolator portion; Fig. 15 is an enlarged sectional view of a portion of Fig. 3A showing a set of air conduits formed in the seal supports included in the canister and isolator door frames and filled with pressurized air to flex and expand seal members included in

those door frames to establish airtight sealing engagement with annular perimeter grooves formed in the canister and isolator doors; Fig. 16 is a view similar to Fig. 15 of a system for distributing pressurized air and vacuum through a pneumatic junction or connecter in the canister and isolator door frames to reach the seal members included in the canister door frames; Fig. 17 is a schematic view of the canister, the isolator, the split transfer port apparatus, and a pneumatic system for selectively inflating and deflating seal members provided in the canister and isolator door frames included in the transfer port assembly ; Fig. 18 is a schematic view similar to Fig. 17 showing mating of the canister and isolator door frames and the seal members included therein in their uninflated positions; Fig. 19A is a schematic view similar to Fig. 18 showing movement of a master valve, two isolator slave valves, and two canister slave valves to opened positions and a pressure selector valve to a positive pressure position causing pressurized air to inflate the seal members mounted on the canister and isolator door frames; Fig. 19B is a schematic view similar to Fig. 19A showing movement of the canister and isolator slave valves back to closed positions so that pressurized air at a seal-inflating pressure is maintained in the canister and isolator supply lines to maintain the seal members mounted on the canister and isolator door frames in their inflated positions even when the canister door frame is disengaged from the isolator door frame (as shown in Fig. 20) during separation of the canister from the isolator ; Fig. 20 is a schematic view similar to Figs. 17-19B showing separation of the canister from the isolator without deflation of the seal members mounted on the canister and isolator door frames; Fig. 21 is a schematic view similar to Fig. 20 showing docking of the canister to a second isolator and transfer of a bottle in the second isolator through a sealed passageway in the transfer port apparatus interconnecting the canister and the second isolator after the canister and isolator slave valves have been moved to their opened positions to cause the seal members mounted on the canister and isolator door

frames to be exposed to a vacuum and deflated to permit removal of the canister and isolator doors so as to open the passageway in the transfer port apparatus ; Fig. 22 is a schematic view of the canister and second isolator of Fig. 21 showing inflation of the seal members and undocking of the canister (loaded with the bottle) from the second isolator; Fig. 23 is a schematic view similar to Fig. 22 showing docking of the canister to a third isolator; Fig. 24 is a schematic view similar to Fig. 23 showing transfer of the bottle from the canister into the third isolator through a transfer port apparatus interconnecting the canister and the third isolator; Fig. 25 is a side view of the canister door frame, the isolator door frame, and the pneumatic system coupled to a pneumatic board showing the configuration of the valves, supply lines, and other components of the pneumatic system; Fig. 26 is a perspective assembly view of components in an alternative transfer port apparatus in accordance with the present invention; Fig. 27 is a block diagram showing a control circuit for use in the rapid transfer port of Fig. 17, a proximity sensor wired to the control circuit and a control panel wired to the control circuit; and Figs. 28-31 cooperate to show a schematic of the control circuit of Fig.

27.

Detailed Description of the Drawings A transfer port apparatus 10 is provided to enable a worker to transfer one or more objects through a sealed passageway or transfer conduit provided in the apparatus 10 from one sealed chamber into another sealed chamber without contaminating clean working environments established in the two sealed chambers as shown, for example, in Figs. 4-14. Transfer port apparatus 10 includes several components as shown in Figs. 1-3A and, as shown in Figs. 1 and 3A-5, is adapted to be coupled to a movable canister 12 formed to include a canister chamber 14 and a stationary isolator 16 formed to include an isolation chamber 18. In most cases,

isolator 16 will be stationary but it could also be movable. In the illustrated embodiment, an object 20 is placed in the airtight clean working environment established in canister chamber 14 and later transferred into the airtight clean working environment established in isolation chamber 18 through a sealed transfer conduit or passageway established in transfer port apparatus 10 following coupling of canister 12 to isolator 16 using transfer port apparatus 10 as shown in Figs. 12 and 13.

Canister 12 includes a shell 22 and a canister wall 24 coupled to shell 22 to define canister chamber 14 as shown in Fig. 1. Canister wall 24 is formed to include an opening 26 arranged to communicate with the transfer conduit formed in transfer port apparatus 10. In the illustrated embodiment, transfer port apparatus 10 includes a canister portion 28 coupled to canister wall 24 at opening 26 and a removable canister door 30 normally closing a passageway established in canister portion 28 and arranged to communicate with canister chamber 14 via opening 26 as shown, for example, in Figs. 3A-5. Canister door 30 is made of aluminum.

Isolator 16 includes a shell 32 and an isolator wall 34 coupled to shell 32 to define isolation chamber 18 as shown in Fig. 1. Isolator wall 34 is formed to include an opening 36 arranged to communicate with the transfer conduit or passageway formed in transfer port apparatus 10. In the illustrated embodiment, transfer port apparatus 10 further includes an isolator portion 38 coupled to isolator wall 34 at opening 36 and a removable isolator door 40 normally closing a passageway established in isolator portion 38 and arranged to communicate with isolation chamber 18 via opening 36 as shown, for example, in Figs. 3A-5. Isolator door 40 is made of aluminum. Canister door 30 and isolator door 40 cooperate to define a conduit closure that can be inserted into the transfer conduit formed in transfer apparatus 10 to occlude the transfer conduit as shown, for example, in Figs. 6 and 7 and that can be removed from the transfer conduit as shown, for example, in Figs. 10-12.

Isolator shell 32 includes a top wall 42, a bottom wall 44, and side walls 46 coupled to walls 42 and 44. One side wall 46 is formed to include a pair of access ports or arm holes 48 and another side wall 46 is formed to include an observation window 50. Access devices 51 such as rubber gloves (not shown) and glove rings are attached to side wall 46 at access ports 48 in an air-tight manner and arranged to

extend into isolation chamber 18 to enable a worker (not shown) alongside isolator 16 to handle object 20 or other material inside isolation chamber 18 without communicating air from the surroundings into isolation chamber 18 (and vice versa).

Although isolator 16 is shown as having a rectangular shape and one of the long side walls 46 is shown to have two access ports 48, it is within the scope of the invention as presently perceived for isolator 16 to have some other shape, be defined by more or fewer side walls 46, and be provided with other types or numbers of access devices and/or observation windows.

Canister portion 28 of transfer port apparatus 10 includes a gasket 52 formed to include a central opening 53 and made of a suitable sealing material, an optional mounting fixture 54 formed to include a central opening 58 and adapted to be coupled to canister wall 24 at opening 26, and a canister door frame 56 coupled to mounting fixture 54. Canister door 30 is configured and sized to open and close a central opening 62 formed in canister door frame 56. Once canister portion 28 of transfer port apparatus 10 is assembled and coupled to canister 12 at opening 26 in canister wall 24, central openings 53,58, and 62 cooperate to define a canister passageway having an outlet communicating with canister chamber 14 via opening 26 in canister wall 24 and an inlet that is closable by engagement of canister door 30 and canister door frame 56 and openable by disengagement of canister door 30 and canister door frame 56. In one embodiment, each of gasket 52, mounting fixture 54, canister door frame 56, and canister door 30 have a somewhat rectangular or oblong ring shape.

Mounting fixture 54 includes a somewhat square-shaped body 64, a first flange 66 appended to one edge of body 64 and adapted to abut gasket 52 and be coupled to canister wall 24 by connectors 67, and a second flange 68 appended to an opposite edge of body 64 and adapted to abut canister door frame 56 as shown in Fig. 3. Mounting fixture 54 further includes an annular shroud 65 surrounding body 64 and coupled to tabs 63 appended to second flange 68 by connectors 61.

Canister door frame 56 includes a seal support ring 70 and a seal member 72 carried on seal support ring 70. Seal member 72 is configured to establish substantially airtight sealing engagement with mounting fixture 54, with canister door

30 when canister door 30 is mounted to close central opening 62 in canister door frame 56, and with isolator portion 38 of transfer port apparatus 10 when canister portion 28 is mated with isolator portion 38. Support ring 70 is made of aluminum and seal member 72 is made of a flexible, expansible, plastic material such as HYPALON material.

Seal member 72 includes a back ring 74, a front ring 76 positioned to lie in axially spaced-apart parallel relation to back ring 74, and an inner ring 78 interconnecting inner edges of back and front rings 74,76. Inner ring 78 is configured to mate with and seal against canister door 30 upon insertion of canister door 30 into central aperture 58 formed in canister door frame 56. In the illustrated embodiment, inner ring 78 includes a first frustoconical section providing surface 80, a second frustoconical section providing surface 82, and an annular ledge 81 positioned to lie between and interconnect surfaces 80 and 82.

Likewise, seal support ring 70 includes a back rim surface 75, a front rim surface 77 positioned to lie in axially spaced-apart parallel relation to back rim surface 75, an inner ring surface 79 interconnecting inner edges of back and front rim surfaces 75,77, and an outer ring surface 87 spaced apart from inner ring surface 79.

In the illustrated embodiment, inner ring surface 79 includes a first portion 73, a second portion 83, and an annular groove portion 85 positioned to lie between and interconnect portions 73,83.

Inner ring 78 of seal member 72 completely covers inner ring surface 79 of seal support ring 70 to form a one-piece covering over inner ring surface 79.

Because inner ring 78 provides a one-piece covering, seal member 72 is easy to clean because there are not multiple pieces of material to clean.

In a preferred embodiment, seal member 72 is"inflated"or expanded using pressurized air to urge an inner surface of seal member 72 against canister door 30 to hold door 30 in place in canister door frame 56 as shown, for example, in Fig.

15. Seal member 72 is"deflated"or contracted using a vacuum source to pull the inner surface of seal member 72 away from canister door 30 to release door 30 from a retained position in canister door frame 56 as shown, for example, in Fig. 16. A

pneumatic system 210 for generating and applying pressurized air and vacuum to seal member 72 is described herein and shown, for example, in Fig. 17.

In the illustrated embodiment, back ring 74, front ring 76, and annular ledge 81 of inner ring 78 are bonded to respective back rim surface 75, front rim surface 77, and annular groove portion 85 of inner ring surface 79 of support ring 70.

First and second frustoconical surfaces 80,82 are not bonded to seal support ring 70.

By providing this bonding arrangement and using a flexible material in seal member 72, first and second frustoconical surface 80,82 will respond to pressures applied to the inner surface of seal member 72 as described herein.

Canister door 30 includes a closure plate 84, a pair of handles 86 coupled to an outer surface of closure plate 84, and a rim 88 around an outer edge of closure plate 84. Rim 88 has an outer surface 90 configured to mate with and seal against inner ring 78 of seal member 72 when canister door 30 is mounted to close central opening 58 in canister door frame 56. For example, rim 88 engages second frustoconical surface 82, annular ledge 81, and a portion of first frustoconical surface 80 as shown in Fig. 3A. Outer surface 90 includes concave face 91 which cooperates with first frustoconical surface 80 of seal member 72 to define a chamber 93 therebetween. As described herein, the first frustoconical surface 80 can be exposed to pressurized air and moved in chamber 93 to engage concave face 91 of outer surface 90 to hold canister door 30 in canister door frame 56 and to facilitate establishment of an airtight seal between canister door frame 56 and canister door 30 as shown, for example, in Fig. 15. Second frustoconical surface 82 can also be exposed to pressurized air as shown in Fig. 15 to substantially seal and hold door 30 in frame 56.

Rim 88 on canister door 30 also has an inner surface 92 formed to include a groove 94 sized to engage a spring-loaded ball detent-type latch member 148 mounted on an underside 150 of isolator door 40 as shown in Fig. 3A. Inner surface 92 of rim 88 and closure plate 84 cooperate to define a cavity 96 containing handles 86 and having an opening facing toward isolator portion 38. Rim 88 also includes a front face 97 formed to include an annular channel 98 containing an annular gasket 99 made of sealing material and adapted to mate with and seal against isolator portion 38 upon coupling canister portion 28 to isolator portion 38 as shown, for example, in Fig. 3A.

Isolator portion 38 of transfer port apparatus 10 includes a gasket 110 formed to include a central opening 111 and made of a sealing material, an isolator door frame 112 formed to include a central opening 115 and coupled to isolator wall 34 at opening 36 by connectors 113, and isolator door 40 configured and sized to open and close central opening 115 formed in isolator door frame 112. Central opening 115 defines an isolator passageway communicating with isolation chamber 18. In a presently preferred embodiment, each of gasket 110, isolator door frame 112, and isolator door 40 have a somewhat rectangular or oblong ring shape.

Isolator door frame 112 includes a seal support ring 116, a mounting flange 118 appended to seal support ring 116, and a seal member 120 carried on seal support ring 116. Seal member 120 is configured to establish substantially airtight sealing engagement with isolator door 40 when isolator door 40 is mounted to close central opening 115 in isolator door frame 112 and with canister door frame 56 of canister portion 28 when isolator portion 38 is mated with canister portion 28. Seal support ring 116 and mounting flange 118 are made of aluminum and seal member 120 is made of a flexible, expansible, plastic material such as HYPALON material.

Seal member 120 includes a back ring 122, a front ring 124 positioned to lie in axially spaced-apart parallel relation to back ring 122, and an inner ring 126 interconnecting inner edges of back and front rings 122,124. Inner ring 126 is configured to mate with and seal against isolator door 40 upon insertion of isolator door 40 into central aperture 115 formed in isolator door frame 112. In the illustrated embodiment, inner ring 126 includes first frustoconical section providing section providing surface 128, second frustoconical section providing surface 130, and an annular ledge 129 lying between and interconnecting surfaces 128 and 130.

Likewise, seal support ring 116 includes a back rim surface 123, a front rim surface 125 positioned to lie in axially spaced-apart parallel relation to back rim surface 123, an inner ring surface 127 interconnecting inner edges of back and front rim surfaces 123,125, and an outer ring surface 89 spaced apart from inner ring surface 127. In the illustrated embodiment, inner ring surface 127 includes a first portion 117, a second portion 131, and an annular groove portion 133 positioned to lie between and interconnect portions 117, 131.

Inner ring 126 of seal member 120 completely covers inner ring surface 127 of support ring 116 to form a one-piece covering over inner ring surface 127.

Because inner ring 126 provides a one-piece covering, seal member 120 is easy to clean because there are not multiple pieces of material to clean.

In a preferred embodiment, seal member 120 is"inflated"or expanded using pressurized air to urge an inner surface of seal member 120 against isolator door 40 in place in isolator door frame 112 as shown, for example, in Fig. 15. Seal member 120 is"deflated"or contracted using a vacuum source to pull inner surface of seal member 120 away from isolator door 40 from a retained position in isolator door frame 112 as shown, for example, in Fig. 16. Pneumatic system 210 generates and applies pressurized air and vacuum to isolator seal member 120 as well as to canister seal member 72.

In the illustrated embodiment, back ring 122, front ring 124, and annular ledge 129 of inner ring 78 are bonded to respective back rim surface 123, front rim surface 125, and annular groove portion 133 of inner ring surface 127 of seal support ring 116. First and second frustoconical surfaces 128,130 are not bonded to seal support ring 116. By providing this bonding arrangement and using a flexible material in seal member 120, first and second frustoconical surfaces 128,130 will respond to pressures applied to the inner surface of seal member 120 as described herein.

Isolator door 40 includes a closure plate 132, a pair of handles 134 coupled to an inner surface of closure plate 132, and a rim 136 around an outer edge of closure plate 132. Rim 136 has an outer surface 138 configured to mate with and seal against inner ring 126 of seal member 120 when isolator door 40 is mounted to close central opening 115 in isolator door frame 112. For example, rim 136 engages second frustoconical surface 130, annular ledge 129, and a portion of first frustoconical surface 128 as shown in Fig. 3A. Outer surface 138 includes annular concave face 139 which cooperates with first frustoconical surface 128 of seal member 120 to define a chamber 141 therebetween. As described herein, first frustoconical surface 128 can be exposed to pressurized air and moved in chamber 141 to engage annular concave face 139 of outer surface 138 to hold isolator door 40 in isolator door

frame 112 and to facilitate establishment of an airtight seal between isolator door frame 112 and isolator door 40 as shown, for example, in Fig. 15. Second frustoconical surface 130 can also be exposed to pressurized air as shown in Fig. 15 to substantially seal and hold door 40 in frame 112.

Closure plate 132 and an inner surface 140 of rim 136 cooperate with underside 150 of isolator door 40 to define a closed cavity 142. Underside 150 of isolator door 40 includes a perimeter lip 143 arranged to mate with annular gasket 99 carried on canister door 30 upon mating engagement of doors 30,40 as shown in Fig. 3A. When isolator door 40 is mated with canister door 30, annular gasket 99 provides a substantial seal therebetween to seal off cavity 96 of canister door 90.

A hinge 144 is provided to couple isolator door 40 to isolator 16 to facilitate movement of isolator door 40 in isolation chamber 18 between a closed position in isolator door frame 112 and an opened position away from central opening 115 in isolator door frame 112 as shown, for example, in Figs. 4-14. Hinge 144 includes several hinge links 146 and each hinge link 146 includes one end pivotably coupled to isolator door 40 and another end pivotably coupled to bottom wall 44 of isolator 16. Movement of isolator door 40 toward and away from isolator door frame 112 during opening and closing of isolator door 40 is controlled by hinge links 146 as shown, for example, in Figs. 5,8, and 13. Hinge links 146 aid in repositioning canister door 30 (coupled to isolator door 40 coupled to hinge links 146) in a proper closure position relative to central opening 58 in canister door frame 112 during movement of doors 30, 40 toward closure positions in transfer port apparatus 10 as shown, for example, in Fig. 13.

Latch members 148 are mounted on isolator door 40 and configured to latch isolator door 40 to canister door 30 to retain isolator door 40 in sealing engagement with isolator door frame 112 when canister door 30 is mounted in central opening 62 of canister door frame 56 and isolator door 40 is mounted in central opening 115 of isolator door frame 112. In the illustrated embodiment, each latch member 148 is a releasable spring-loaded detent coupled to underside 150 of isolator door 40 and configured to engage groove 94 formed in inner surface 92 of canister door rim 88 as shown in Fig. 3A.

As shown in Fig. 3A, latch member 148 includes a base 152 fixed to underside 150 of isolator door 40 and a ball retainer 154 coupled to base 152 and formed to include an opening 156 positioned to lie in close proximity and confronting relation to groove 94 in canister door 30 upon placement of isolator door 40 in central opening 115 of isolator door frame 112. Latch member 148 also includes a ball 158 mounted for movement in a passageway formed in ball retainer 154 to communicate with opening 156 and a yieldable spring 160 arranged to bias ball 158 in passageway through opening 156 into groove 94 and engagement with rim 88 of canister door 30 so as to establish a releasable latching connection of isolator door 40 to canister door 30. Ball retainer 154 includes an outer surface end configured to engage threads formed in an aperture 162 formed in base 152 to facilitate adjustment of the position of ball retainer 154 and spring-biased ball 158 relative to groove 94 in canister door 30 during latching of isolator door 40 to canister door 30. Latch members 148 are commercially available ball plungers. The arrangement of latch members 148 on isolator door 40 is shown in Fig. 3B.

Use of transfer port apparatus 10 to transfer object 20 from canister chamber 14 in movable canister 12 into isolation chamber 18 in isolator 16 is shown, for example, in Figs. 4-13 and later disengagement of canister 12 from isolator 16 following such transfer is shown in Fig. 14. Use of a pneumatic system 210 to inflate canister seal member 72 in canister door frame 56 to hold canister door 30 in canister door frame 56 and assist in establishing an airtight seal against canister door 30 and to inflate isolator seal member 120 in isolator door frame 112 to hold isolator door 40 in isolator door frame 112 and assist in establishing an airtight seal against isolator door 40 is shown diagrammatically in Figs. 17-24.

Referring to Figs. 4 and 5, canister 12 containing object 20 in airtight chamber 14 is moved to lie next to stationary isolator 16 having an empty isolation chamber 18. Canister door 30 is mounted in canister door frame 56 included in canister portion 28 of transfer port apparatus 10 to close central opening 62 in canister door frame 56 and establish an airtight seal against canister door frame 56 to maintain an airtight clean environment in canister chamber 14 formed in movable canister 12.

Canister 12 can be moved about easily to enable a worker (not shown) to transport

object 20 in an uncontaminated sterile environment to and from isolator 16. Isolator door 40 is mounted in isolator door frame 112 included in isolator portion 38 of transfer port apparatus 10 to close central opening 115 in isolator door frame 112 and establish an airtight seal against isolator door frame 112 to maintain an airtight clean working environment in isolator chamber 18 formed in stationary isolator 16.

Referring now to Figs. 4,6, and 8, canister portion 28 is coupled to isolator portion 38 to establish transfer port apparatus 10 having one end connected to canister 12 at opening 26 and an opposite end connected to isolator 16 at opening 111.

Both doors 30,40 remain in their closed and sealed positions in their respective door frames 56,112 to close the passageway extending from canister chamber 14 in canister 12 to isolation chamber 18 in isolator 16 through transfer port apparatus 10.

Referring now to Figs. 8 and 9, isolator door 40 has been pivoted on hinge 144 by a worker (not shown) accessing isolator door 40 in isolation chamber 18 through access ports 48 to an opened position lying on bottom wall 44 in isolation chamber 18 to open central opening 115 in isolator door frame 112. Canister door 30 is now accessible to the worker through central opening 115. At this stage, however, canister door 30 remains in its closed and sealed position in canister door frame 56 to close the passageway extending from canister chamber 14 through canister portion 28 of transfer port apparatus 10.

Referring now to Figs. 10 and 11, canister door 30 has been moved to an opened position and coupled to isolator door 40 by latch members 148 to open central opening 62 in canister door frame 56. The transfer conduit or passageway formed in transfer port apparatus 10 is now opened to interconnect canister chamber 14 and isolation chamber 18 in fluid communication to enable a worker to move bottle 20 from canister chamber 14 into isolation chamber 18 through that transfer conduit as shown in Fig. 12. Canister door 30 can also be latched to isolator door 40 and removed simultaneously with isolator door 40.

Once object 20 has been moved into isolation chamber 18 as shown in Fig. 13, canister door 30 and isolator door 40 can be returned to passageway-closing positions in transfer port apparatus 10 to establish an airtight, sealed, working environment in isolation chamber 18. Canister door 30 can be returned separately or

simultaneously with isolator door 40. After seal members 72,120 have been inflated, canister portion 28 can then be disengaged from isolator portion 38 to enable a worker to separate canister 12 from isolator 16 without disrupting the uncontaminated sterile environments in canister chamber 14 and isolation chamber 18 as shown in Fig. 14.

Pneumatic pressure is controlled and delivered to inflate and deflate seal members 72,120 by a pneumatic system 210, a preferred embodiment of which is shown diagrammatically in Fig. 17. Pneumatic system 210 includes a positive pressure (compressed air) supply 212, a vacuum supply 214, a pressure selector valve 216, a master valve 218, a pair of isolator slave valves 220,222, a pair of canister slave valves 224,226, a filter regulator 228, a supply regulator 230, and an electrical circuit 232 for controlling operation of pressure selector valve 216 and master valve 218.

Pressure selector valve 216 and master valve 218 are commercially available solenoid valves and slave valves 220,222, 224,226 are commercially available pilot valves. It is understood, however, that a wide variety of commercially available valves may be used in pneumatic system 210 in accordance with the present invention. Many of the components in pneumatic system 210 are mounted on a pneumatics board 227 shown diagrammatically in Fig. 17 and illustratively in Fig. 25. In a preferred embodiment, electrical circuit 232 is mounted on the backside of pneumatics board 227.

As shown in Fig. 17, pneumatic system 210 further includes a series of pneumatic supply lines fluidly connecting positive pressure supply 212 and vacuum supply 214 to pressure selector valve 216, master valve 218, isolator slave valves 220, 222, canister slave valves 224,226, seal member 72 in canister door frame 56, and seal member 120 in isolator door frame 112. The pneumatic supply lines in pneumatic system 210 include a positive pressure supply line 234 including a main branch 236 that conducts pressurized air from positive pressure supply 212 to a junction 238 through a filter dryer 240 and filter regulator 228 via conduits 242,244, and 246.

Filter regulator 228 regulates the pressure of air discharged through conduit 256 to junction 238 to within an acceptable predetermined pressure range. Filter dryer 240 removes water from pneumatic system 210. The pneumatic supply lines in pneumatic system 210 further include a master branch 248 that conducts pressurized air from junction 238 to master valve 218 and a pressure supply branch 250 that conducts

pressurized air from junction 238 to pressure selector valve 216 through supply regulator 230. The pneumatic supply lines in pneumatic system 210 also include a vacuum supply line 252 that supplies negative pressure from vacuum supply 214 to pressure selector valve 216.

Circuit 232 controls operation of pressure selector and master valves 216,218 to regulate the flow of pressurized air from positive pressure supply 212 and vacuums generated by vacuum supply 214 to seal member 72 in canister door frame 56 and to seal member 120 in isolator door frame 112. Circuit 232 is wired to pressure selector valve 216 through a lead 254 and master valve 218 through a lead 256. A user of transfer port apparatus 10 inputs commands into a control panel 258 coupled to circuit 232 to control the operation of pressure selector and master valves 216,218.

In one embodiment, the series of pneumatic supply lines in pneumatic system 210 further include a slave supply line 260 including a main branch 262 that provides negative pressure from vacuum supply 214 to a junction 264, an isolator branch 266 that provides negative pressure from junction 264 to control ports 267 of isolator slave valves 220,222, and a canister branch 268 that provides negative pressure from junction 264 to control ports 269 of canister slave valves 224,226 through a pneumatic junction 270. As shown in Fig. 16, pneumatic junction 270 includes pneumatic couplings 341, a hollow pin 272, a plurality of O-rings 274 coupled to an exterior wall of hollow pin 272 and a pin-receiving aperture 276 formed in support ring 70 of canister door frame 56. When canister 12 is coupled to isolator 16, pin 272 is aligned with and inserted into pin-receiving aperture 276 so that 0-rings 274 form a seal between pin 272 and support ring 70.

As shown in Fig. 17, the series of pneumatic supply lines in pneumatic system 210 further include a pressure supply line 280 including a main branch 282 that provides pressure from an outlet port 284 on pressure selector valve 216 to a junction 286, an isolator branch 288 that provides pressure from junction 286 to an inlet port 290 on first isolator slave valve 220, and a canister branch 292 that provides pressure from junction 286 to an inlet port 294 on first canister slave valve 224 through a pneumatic junction 296. Pneumatic junction 296 of pressure supply line 192 is similar in construction to pneumatic junction 270 of slave supply line 260.

Referring to Fig. 17, first isolator slave valve 220 is pneumatically coupled to second isolator slave valve 222 from an outlet port 298 on first isolator slave valve 220 to an inlet port 310 on second isolator slave valve 222 through a line 312. Likewise, first canister slave valve 224 is pneumatically coupled to second container slave valve 226 from an outlet port 314 on first container slave valve 224 to an inlet port 316 on second container slave valve 226 through a line 318. First and second isolator slave valves 220,222 are arranged in series so that if one of valves 220,222 fails, the other of valves 220,222 will function. Likewise, first and second canister slave valves 224,226 are arranged in series so that if one of valves 224,226 fails, the other of valves 224,226 will function.

Pressure supply line 280 further includes an isolator seal supply line 320. Supply line 320 provides pressure from an outlet port 322 on second isolator slave valve 222 to isolator seal member 120 through passageways 321 formed in support ring 116 of isolator door frame 112 and a canister seal supply line 324 that provides pressure from an outlet port 326 on second container slave valve 226 to canister seal member 72 through passageways 325 formed in support ring 70 of canister door frame 56. These passageways 321,325 are shown, for example, in Figs.

3A and 1 S.

Air conduits such as passageways 321, 325 are formed in isolator and canister door frames 112, 56 through a series of machining operations to include respective main segments 327, 329 and branch segments 331, 333 as shown in Fig. 15.

Main segments 327,329 are formed by drilling into front rim surface 125 of respective support ring 116 of isolator door frame 112 and back rim surface 75 of support ring 70 of canister door frame 56 to create openings 335. Likewise, branch segments 331, 333 are formed by drilling into outer ring surfaces 89,87 of respective support rings 116, 70 of isolator and canister door frames 112, 56 creating first and second openings 337, 339.

Passageways 321,325 are coupled to pneumatic system 210 by couplings 341 to permit the delivery of pressurized air to canister and isolator seal members 72,120. A coupling 341 is inserted into opening 335 of canister door frame 56 to deliver air from canister seal supply line 324 as shown in Fig. 15. Opening 335

of isolator door frame 112 is welded shut. Another coupling 341 is inserted into second opening 339 of isolator door frame 112 to deliver air from isolator seal supply line 320 as shown in Fig. 15. First openings 337 of canister and isolator door frames 112,56 and second opening 339 of canister door frame 56 are sealed by set screw-like plugs 343.

Each of the valves included in pneumatic system 210 includes a valve body that is movable between first and second positions to couple or decouple certain of the pneumatic supply lines in pneumatic system 210. Each valve body includes two air/vacuum controller segments that are shown diagrammatically in Figs. 17-24. These air/vacuum controller segments are arranged so that a first of the air/vacuum controller segments operate to pass or block flow of compressed air or vacuum through the valve body when the valve body is moved to its first position and a second of the air/vacuum controller segments operate to pass or block flow of compressed air or vacuum through the valve body when the valve body is moved to its second position.

Pressure selector valve 216 includes a first controller segment 330 configured to couple vacuum supply line 252 to main branch 282 of pressure supply line 280 and"cap off'pressure supply branch 250 of positive pressure supply line 234 when pressure selector valve 216 is moved to assume its negative pressure position shown in Figs. 17 and 18. Pressure selector valve 216 also includes a second controller segment 332 configured to couple pressure supply branch 250 of positive pressure supply line 234 to main branch 282 of pressure supply line 280 and cap off vacuum supply line 252 when pressure selector valve 216 is moved to assume its positive pressure position shown in Fig. 19A.

Master valve 218 includes a first controller segment 334 configured to couple main branch 262 of slave supply line 260 to master branch 248 of positive pressure supply line 234 when master valve 218 is moved to assume its opened position shown in Fig. 19A. Master valve 218 also includes a second controller segment 336 configured to decouple main branch 262 of slave supply line 260 and master branch 248 of positive pressure supply line 234, cap off master branch 248, and open main branch 262 to atmosphere when master valve 218 is moved to assume its closed position shown in Figs. 17 and 18.

Each of isolator slave valves 220,222 includes a first controller segment 338 decoupling isolator branch 288 and isolator seal supply line 320 in pressure supply line 280 to block flow of compressed air or vacuum to isolator seal member 120 when either one of isolator slave valves 220,222 is moved to assume its closed (first) position shown in Fig. 17. Each of isolator slave valves 220,222 includes a second controller segment 340 coupling isolator branch 288 and isolator seal supply line 320 to permit flow of compressed air to or apply vacuum to isolator seal member 120 when both of isolator slave valves 220,222 are moved to assume their opened (second) positions shown in Fig. 19A.

Each of canister slave valves 224,226 includes a first controller segment 342 decoupling canister branch 292 of pressure supply line 280 and canister seal supply line 324 to block flow of compressed air or vacuum to canister seal member 72 when either one of canister slave valves 224,226 is moved to assume its closed (first) position shown in Fig. 17. Each of canister slave valves 224,226 includes a second controller segment 344 coupling canister branch 292 to canister seal supply line 324 to permit flow of compressed air or apply vacuum to canister seal member 72 when both of canister slave valves 224,226 are moved to assume their opened (second) positions shown in Fig. 19A.

Initial sterilization of canister 12 when coupled to an empty first isolator 16'and later use of canister 12 to receive an object 20 from a second isolator 16"and transfer that object 20 to a third isolator 16"'is shown diagrammatically in Figs. 17-24.

This sterilization of canister 12 and subsequent transfer of object 20 to and from canister 12 is accomplished through a series of steps. To begin, canister 12 and first isolator 16'are sealed and sterilized as shown in Figs. 17 and 18. Doors 30, 40 are positioned to lie in respective frames 56,112 and sealed as shown in Figs. 19A and 19B. Canister 12 is then uncoupled from first isolator 16'as shown in Fig. 20 and coupled to second isolator 16"containing object 20 as shown in Fig. 21. The transfer port apparatus 10 interconnecting canister 12 and second isolator 16"is opened by removing canister door 30 and isolator door 40 and object 20 is then moved from second isolator 16"into mobile canister 12 through an opened passageway in transfer port apparatus 10 as shown in Fig. 21. After positioning doors 30,40 in respective

frames 56,112, canister 12 (now containing object 20) is then undocked from second isolator 16"as shown in Fig. 22 and moved to dock with third isolator 16"'as shown in Fig. 23. Object 20 is then transferred from mobile canister 12 into third isolator 16"'.

This transfer process is illustrated in Fig. 24. Objects can also be transferred from isolator to isolator by coupling the isolators directly to one another.

As shown in Fig. 17, in the beginning, canister 12 is not coupled to first isolator 16'and isolator door 40 is not coupled to canister door 30. Neither canister 12 nor first isolator 16'have been sterilized. Master valve 218 is in the closed position so that vacuum supply 214 has uninterrupted negative pressure access to slave supply line 260. Vacuum supply 214 through slave supply line 260 applies negative air pressure to control ports 267 of isolator slave valves 220,222 and to control ports 269 of canister slave valves 224,226 so that all slave valves 220,222, 224,226 are in their closed positions blocking flow of pressurized compressed air from positive pressure supply 212 to either canister seal member 72 or isolator seal member 120. Seal members 72,120 are in an uninflated position and canister door frame 56 is thus ready to receive canister door 30 therein and isolator door frame 112 is ready to receive isolator door 40 therein. Pressure selector valve 216 is in the negative pressure position capping off pressure supply branch 250.

Because canister 12 and first isolator 16'are exposed to the atmosphere, potential contaminates (not shown) could have entered canister 12 and first isolator 16'and spoiled the clean environment therein. Therefore, canister 12 and first isolator 16'must be sterilized with a hydrogen peroxide mist or other suitable sterilization process. To sterilize canister 12 and first isolator 16', canister 12 is coupled to first isolator 16'and a latch 57 is placed in a locked position to secure and seal canister door frame 56 to isolator door frame 112 as shown in Fig. 18. While in the locked position, canister 12 and first isolator 16'maintain a substantially air-tight seal therebetween. Isolator door 40 is also coupled to canister door 30 maintaining a substantially air-tight seal therebetween. Next, canister chamber 14 of canister 12 and isolation chamber 18 of first isolator 16'and exposed surfaces of coupled canister and isolator doors 30, 40 and transfer port apparatus 10 are exposed to the hydrogen peroxide mist (not shown) or other suitable sterilizing process.

Having just sterilized canister 12, first isolator 16', and exposed surfaces of canister and isolator doors 30, 40 and transfer port apparatus 10, it is then possible to disengage canister 12 from first isolator 16'and move canister 12 to engage second isolator 16"to enable a worker to transfer object 20 from second isolator 16" into movable canister 12 for transport to third isolator 16"' (or, for that matter, to first isolator 16'). To"undock"canister 12 from isolator 16, pneumatic system 210 is operated to inflate canister seal member 72 and isolator seal member 120 to"hold" canister and isolator doors 30,40 in pressure-locked retained positions in respective canister and isolator door frames 56,112 and canister door frame 56 is unlatched and then disengaged from isolator door frame 112. To"dock"canister 12 to isolator 16, canister door frame 56 is mated and latched to isolator door frame 112 to establish transfer port apparatus 10 between canister 12 and isolator 16 and then pneumatic system 210 is operated to deflate canister seal member 72 and isolator seal member 120 to"release"canister and isolator doors 30,40 from"pressure-locked"retained positions in canister and isolator door frames 56,112.

To retain canister and isolator doors 30,40 in door frames 56,112, seal members 72,120 are inflated using compressed air and moved to the inflated positions as shown in Fig. 19A. In order to move seal members 72,120 to their inflated positions, circuit 232 is operated to move master valve 218 to an opened position conducting compressed air at a positive pressure from positive pressure supply 212 to control ports 267 of isolator slave valves 220,222 and control ports 269 of canister slave valves 224,226 through slave supply line 260. This positive pressure at control ports 267,269 moves all four slave valves 220,222, 224,226 from their closed positions shown in Fig. 18 to their opened positions shown in Fig. 19A.

At approximately the same time as slave valves 220,222, 224,226 are being opened, circuit 232 operates to move pressure selector valve 216 from its negative pressure position shown in Fig. 18 to its positive pressure position shown in Fig. 19A to conduct compressed air from positive pressure supply 212 (1) along a first path to inlet port 290 of first isolator slave valve 220 through main branch 282, junction 286, and isolator branch 288 and on to inlet port 310 of second isolator slave valve 222 through line 312 into isolator seal supply line 320 and (2) along a second

path through main branch 282, junction 286, and canister branch 292 to inlet port 294 of first canister slave valve 224 and on to inlet port 316 of second canister slave valve 226 through line 318 into canister seal supply line 324. The compressed air moving in isolator seal supply line 320 reaches and inflates isolator seal member 120 while the compressed air moving in canister seal supply line 324 reaches and inflates canister seal member 72 as shown in Fig. 19A.

After a short predetermined time delay set by a timer included in circuit 232, master valve 218 is moved to its closed position causing all four slave valves 220, 222,224, 226 to be exposed to vacuum at control ports 267,269 and then moved to their closed positions by the vacuum as shown in Fig. 19B. The pressurized air applied to canister seal member 72 is"locked"in canister seal supply line 324 by closed canister slave valves 224,226. The pressurized air applied to isolator seal member 120 is locked in isolator supply line 320 by closed isolator slave valves 220,222. After the pressurized air is locked in canister seal supply line 324 and in isolator supply line 320, pressure selector valve 216 optionally moves to is negative pressure setting.

Having inflated seal members 72 and 120, latch 57 is moved from a locked position to an unlocked position to enable a worker to move canister 12 away from first isolator 16'as shown in Fig. 20. Isolation chamber 18 in first isolator 16'and canister chamber 14 in canister 12 remain unspoiled because seal members 72,120 are still expanded by positive pressure in respective canister and isolator seal supply lines 324,320 so that doors 30,40 are in the retained and sealed positions in door frames 56,112 and maintain a substantial seal between the environment and respective interior chambers 14,18.

Because canister 12 is separated from first isolator 16', it can be docked to another isolator 16"as shown in Fig. 21. To couple canister 12 to second isolator 16 ", canister door frame 56 of canister 12 and isolator door frame 112 of second isolator 16"must be aligned so that hollow pin 272 in pneumatic junction 270 aligns with and fits into pin-receiving aperture 276 in canister door frame 56 and a hollow pin 295 in pneumatic junction 296 aligns with and fits into a pin-receiving aperture 297 in canister door frame 56.

Having aligned canister 12 with second isolator 16 ", canister 12 is then coupled to second isolator 16"as shown in Fig. 21. This coupling secures isolator door 40 to canister door 30 using plurality of latch members 148 as previously discussed. Latch 57 is also moved from the unlocked position to the locked position.

Having locked and sealed canister 12 onto second isolator 16 ", seal members 72,120 are deflated and are retracted from grooves 91,139 so that isolator and canister doors 40, 30 are no longer retained in door frames 112, 56 as shown in Fig. 21. Seal members 72,120 are retracted from grooves 91, 139 by negative pressure supplied by vacuum supply 214 via respective canister seal supply line 324 and isolator seal supply line 320. In order to move seal members 72,120 to the deflated positions, circuit 232 is operated to move master valve 218 to an opened position providing positive pressure from positive pressure supply 212 to control ports 267,269 of respective slave valves 220,222, 224,226 through slave supply line 260.

This positive pressure at control ports 267,269 moves slave valves 220,222, 224,226 from the closed positions shown in Fig. 20 to the opened positions as shown, for example, in Fig. 21.

At approximately the same time a slave valves 220,222, 224,226 are being opened, circuit 232 moves pressure selector valve 216 to its negative pressure position as shown in Fig. 21 providing negative pressure from vacuum supply 214 to inlet port 290 of first isolator slave valve 220 and to inlet port 294 of first canister slave valve 224. Because first slave valves 220,224 are in the opened position as mentioned above, negative pressure draws air from control lines 320,324 coupled to seal members 120,72 through second slave valves 222,226 to first slave valves 220, 224. Likewise, because first slave valves 220,224 are in the opened position as mentioned above, negative pressure draws air through first slave valves 220,224 to vacuum supply 214 and an exhaust 215. The withdrawal of air from control lines 320, 324 retracts seal members 72,120 to their deflated positions as shown in Fig. 21.

Because latch 57 remains in the locked position, canister 12 remains substantially sealed to second isolator 16"even though seal members 72,120 are deflated. Next, isolator door 40 and canister door 30 are removed into isolation

chamber 18"of second isolator 16"so that object 20 can be placed within canister chamber 14 of canister 12 as shown in Fig. 21.

As shown in Fig. 20, certain exterior portions of mounted isolator door 40 and mounted canister door 30 will be exposed to the atmosphere upon separation of canister 12 from first isolator 16'. However, as shown best in Fig. 3A, these portions will be isolated together inside the annular seal established by mating engagement of seal 99 on canister door frame 56 and perimeter rim 143 on isolator door frame 112 upon coupling of canister and isolator doors as shown in Fig. 21 to block contamination of second isolator 16"upon movement of doors 30,40 from transfer port apparatus 10 into isolation chamber 18"of second isolator 16".

After object 20 is transferred from second isolator 16"into canister 12, doors 30,40 are positive to lie within respective frames 56,112, seal members 72,120 are reinflated, and canister 12 is separated from second isolator 16"as shown in Fig.

22. Canister 12 can then be docked to a third isolator 16"' (or any other isolator) as shown in Fig. 23 and, after seal members 72,120 are deflated and doors 30, 40 are removed, object 20 can be transferred through transfer port apparatus 10 into an isolation chamber 18"'in third isolator 16"'.

An alternative embodiment of transfer port apparatus 10 is shown in a Fig. 26. Apparatus 410 is very similar to apparatus 10 and includes a canister portion 428, an isolator portion 438, a canister door 430, and an isolator door 440. Canister portion 428 includes a gasket 452, a mounting fixture 454, a shroud 465, and a canister door frame 456. Isolator portion 438 includes a gasket 510 and isolator door frame 512. An inflatable seal 472 is mounted on canister door frame 456 and an inflatable seal 520 is mounted on isolator door frame 512.

In a preferred embodiment, when a user actuates circuit 232 to "deflate"or contract seal members 72,120, circuit 232 moves master valve 218 to the open position so that positive pressure is supplied through slave supply line 260 to control ports 267 of isolator slave valves 220,222 and to control ports 269 of canister slave valves 224,226 so that all slave valves 220,222, 224,226 are in their open positions allowing flow of air away from canister seal member 72 and isolator seal member 120. At approximately the same time, circuit 232 moves pressure selector

valve 216 to its negative pressure position providing negative pressure from vacuum supply 214 to inlet port 290 of first isolator slave valve 220 and to inlet port 294 of first canister slave valve 224. Because first slave valves 220,224 are in the opened position as mentioned above, negative pressure draws air from control lines 320,324 coupled to seal members 120,72 through second slave valves 222,226 to first slave valves 220,224. Further, because first slave valves 220,224 are also in the opened position as mentioned above, negative pressure draws air through first slave valves 220,224 to vacuum supply 214 and an exhaust 215. The withdrawal of air from control lines 320,324 retracts seal members 72,120 to their deflated positions.

Electrical circuit 232 is used to control master valve 218 and pressure selector valve 216 based on user input from control panel 258. Control panel 258 includes a switch 610 and an in-process lamp 616 to indicate the current status of the apparatus. Control panel 258 has two normally-high outputs, CL 618 (Fig. 29) and OP 620 (Fig 30). Selecting the"open"position 614 of switch 610 grounds OP 620, and selecting the"close"position 612 grounds CL 618.

The selecting of inputs CL 618 and OP 620 is similar. Consequently, a description of the processing of CL 628 should suffice for an understanding of the processing of OP 620 as well. Figs. 29,30 and 31 utilize similar numbers to denote similar circuits on the two signal paths, with the distinction that the circuit components which process the OP signal at 620 are designated by a prime ('). Once the CL signal at 618 is detected by circuit 232 it first passes through a debounce circuit 624 to clear any switch noise. The illustrated embodiment utilizes a Motorola type MC14490 hex contact bounce eliminator. The output signal from debounce circuit 624 is coupled to a delay circuit to provide a momentary"high"signal. This delay circuit is realized in the illustrated embodiment by supplying the output signal from debounce circuit 624 to a NOR gate 626, and to a delay buffer 628. In the illustrated embodiment, another section of the MC 14490 IC provides the delay buffer 628. The delayed signal is then inverted by an inverter 630. The output of the inverter 630 is coupled to an input of NOR gate 626. The signal from debounce circuit 624 initially forces NOR gate 626 to output a "high"signal. Once the inverted delayed signal reaches NOR gate 626, the output of NOR gate 626 turns off.

The signal from the NOR gate 626 is used to activate a trigger circuit 632, illustrated as a Motorola MC14538 monostable multivibrator configured to be a rising edge trigger. A 100K ohm resistor 634 and a. luF capacitor 636 are utilized to determine the correct trigger timing. Once trigger circuit 632 detects the signal from NOR gate 626, a"high"trigger signal is generated. The output of trigger circuit 632 is coupled to both pressure solenoid driver 646 and master solenoid driver 644 (jointly referred to as"drivers 646,644") inputs to allow the trigger signal to activate both drivers 646,644. A major difference between the CL 618 input path and the OP 620 input path is that the output of trigger circuit 632'for OP 620 is coupled only to an input of master solenoid driver 644.

Both drivers 646,644 are configured to emit a timed signal to control the pressure selector valve 216 and the master valve 218 respectively. In the illustrated embodiment each driver utilizes one half of a Motorola type MC3456 timing circuit 647. The MC3456 timer 647 has only one input pin per half (pins 6 and 8). These inputs are active-low. To allow trigger 632,632'to properly activate the drivers 646,644 a NOR gate 648 is used to input signals from both triggers 632,632' to MC3456 647'. A NOR gate 676 is used to invert the output from trigger 632 for input into MC3456 647. Master solenoid driver 644 is configured to emit a 7 second "high"signal. To select the correct timing for the signal, a 511k ohm resistor 650 and a lOuF capacitor 652 are coupled to pin 12 and between power and ground. Pressure solenoid driver 646 is configured to emit an 8 second "high"signal. To select the correct timing for the signal, a 619k ohm resistor 670 and a lOuF capacitor 652'are coupled to pin 2 and between power and ground. In the illustrated embodiment each driver 646,644 uses a relay 674,656 to provide switched power to valves 216 and 218. The relay is triggered into conduction by the"high"signal from MC3456,647.

LED 668,668'is connected between the relay 674,656 switched power output and ground. Relay 656 on master solenoid driver 644 also includes a second switched power output 666 to provide power to in-process lamp 616 while the master valve 218 is activated.

Both triggers 632, 632' and drivers 644,646 also have RESET terminals which can be activated to disable the possibility of a false signal being sent. Triggers

632,632'have a RESET terminal connected to a proximity sensor 640. Proximity sensor 640 is configured to sense when canister portion 28 is connected to isolator portion 38. The output generated by proximity sensor 640 is"high"if the portions 28, 38 are not connected, while the signal generated is"low"when the portions 28, 38 are connected. In the illustrated embodiment the multivibrators of triggers 632,632', have active-low RESET so the output of the proximity sensor must be inverted by inverter 638 whose output is then coupled to the RESET terminals of triggers 632,632'. This connection to the sensor ensures that the valves will be operated only when the two portions 28 and 38 are connected. The drivers 646,644 have a RESET terminal configured to disable the circuit when neither of the switched positions are selected. In the illustrated embodiment CL input 618 and OP input 620 and coupled to the inputs of a NAND gate 678. The output of NAND gate 678 is coupled to the RESET terminals of MC3456 timer IC 647.

Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.