Patent Publication Number: US-11389674-B2

Title: Method and device for connecting a protective cover to a safety cover sealed against the environment

Description:
FIELD OF THE INVENTION 
     The invention relates to a method for connecting an at least partially flexible protective cover, which forms a barrier between a contaminated area and an uncontaminated area, to an at least partially flexible safety cover sealed against the environment. Furthermore, the invention relates to a device for sealing the connection of a protective cover to a safety cover against the environment, in particular for performing such method. 
     Such method can be used to transfer a content situated in a protective cover, which is protected against contamination by the protective cover, from a contaminated area to an area protected against contamination, such as a clean room or a manipulator room. The transfer shall be performed in an environmentally sealed manner, i.e. without any risk of contamination of the content inside the protective cover, in particular without the introduction of germs and pathogens, such as viruses. The protective cover may be a coverall for the transfer of a person or a protective packaging for sterile objects, which are secured against contamination by the packaging and which are to be transferred sealed against the environment, i.e. protected, for instance into a manipulator room. 
     DE 100097514 B1 discloses a process of the type mentioned above. This process provides for a zipper to be used on the docking or transfer area, both on the protective cover, such as a coverall or packaging, and on the safety cover, for instance the enclosure of a protective space, to form an opening permitting the transfer. The zip fasteners are covered by respective sheetings, which sheetings are held in the covering position by interacting hook-and-loop fastener elements. From the covering position, the sheetings can be folded over by pulling the hook-and-loop fastener connection apart such that they can come into binding engagement with the corresponding hook-and-loop fastener parts on the matching other cover and thereby create a sealed connection between the protective cover and the safety cover, after which the transfer opening can be created by opening both zip fasteners. 
     The connection established by the known method does not provide sufficient protection against contamination. To perform the docking procedure, the covering sheetings of both zippers have to be lifted from the closed position exposing the zipper concerned until the hook-and-loop connection is restored on both covers. Because the respective zipper does not form an environmentally sealed barrier, at this stage of the process the joint is unprotected. Even after the hook-and-loop fastener connection between both covers has been established, protection is insufficient because a connection between the hook-and-loop fastener elements is not completely sealed against the environment. 
     SUMMARY OF THE INVENTION 
     Based on this state of the art, the invention addresses the problem of specifying a process of the type mentioned above, permitting a particularly safe connection to be established between the two covers in question, which process also provides protection against microbiological contamination. 
     Accordingly, the invention provides for at least the following process stages when covers are used, which covers are formed at least partially of a film material, which can be sealed to produce at least one film joint:
         a) arranging a receiving end of the safety cover opposite from an end of the protective cover penetrating into the end of the former in a docking area;   b) bringing the ends of the two covers together in the docking area;   c) severing the ends and sealing adjacent film parts of the two covers along a joint seal, which shall delimit the joint seal after a passage opening is opened; and   d1) transferring the protective cover out of the contaminated area
           by inverting the protective cover over the opening such that its inside is turned out and then severing it from the safety cover and closing the opening; or   
           d2) transferring the protective cover out of the contaminated area by sheathing the protective cover with the safety cover as it is pulled through the passage and subsequently severing of both covers from the safety cover and closing the sheathing; or   d3) pulling the protective cover back into the contaminated area and then sealing the ends to sever the safety cover by forming a further sealed joint between adjacent film parts.       

     The docking process is performed in the docking area between the safety cover and the protective cover in accordance with the stages a and b. The docking area, which is preferably located on the outer wall of a protective space or on an airlock chamber of a manipulator room, has a passage for the transfer of the contents of the protective cover to the protective space or airlock chamber. During all process stages a) to d3), the safety cover forms the hermetic seal of this passage. The safety cover is attached to the edge of the passage in the form of a closed, expandable hose, the closed end of which spans the passage over its entire surface before the docking stages a) and b) have been completed. The docking procedure can be performed such that the area of the safety cover forming the receiving end is moved away from the surface, forming a connecting area for the end of the protective cover, into which connecting area this end of the protective cover can penetrate to bring the ends of both covers together in stage b). Corresponding to stage c), the adjacent ends of the two covers are sealed. The sealing operation is a cut and seal process, such that the end parts lying beyond the sealing line are cut off as waste, and such that the sealed joint is manufactured in a peelable manner. An opening then can be formed between the two pairs of films of the protective cover and the safety cover, which are interconnected to transfer the contents of the protective cover to the outside. 
     This method can be performed in accordance with stage d1) by inverting the protective cover over the opening such that the inside of the protective cover including the contents is turned outwards. Then both the connection area of the safety cover is hermetically sealed again by cutting and sealing, and the unit having the inverted protective cover is severed for disposal. Alternatively, the transfer according to stage d2) can be performed such that the protective cover is sheathed by the safety cover when the safety cover is pulled through the passage. Then both covers are severed from the safety cover while simultaneously closing the sheath. Again, a unit is available for disposal, in which unit a contaminated area is completely closed towards the outside by the surrounding safety cover. In comparison to variant d1), where the inverted protective cover with the non-contaminated inside itself forms the enclosure of the contaminated area, the required film surface area for the safety cover is greater in the variant according to d2). However, this situation is countered by the advantage of a simplified sequence of the process because the inversion process is omitted. 
     In variant d3) the protective cover is pulled back into the contaminated area and subsequently the ends are sealed to sever the safety cover by forming a further sealed joint between adjacent film parts. This variant results in the advantage that the contaminated covers, the safety cover and the protective cover are returned from the uncontaminated area into the contaminated area and can remain there. 
     When performing the procedure according to variant d1), a contaminated area is enclosed inside the inverted protective cover thereby closing the passage opening. In the procedure according to variant d2), a closed intermediate area is formed as the contaminated area when the safety cover is used to sheath the protective cover thereby closing the sheathing. Where the technical term sealing is used, this includes the production of peelable closure parts. 
     The subject matter of the invention is also a device for connecting a protective cover to a safety cover in a manner sealed against the environment, in particular for performing the method according to the invention. Advantageous features of the invention are provided. 
     A device according to the invention for sealing a protective cover to a safety cover against the environment comprises a dispensing device for a sealable film material which, dispensed as a film tube, comprises a passage for a transfer from a contaminated area into an uncontaminated area using a protective cover. The at least partially flexible safety cover hermetically seals the contaminated area from the uncontaminated area. At least one sealing device produces at least one preferably peelable film connection between layered sheeting parts of the safety cover and the relevant protective cover. One end of the protective cover, during transfer from the contaminated area to the uncontaminated area in a docking area, penetrates into a receiving end of the safety cover. 
     Advantageously, the safety cover is designed in the manner of a film tube, the free end of which remains closed in the docking area before the passage opening is produced and after the protective cover is dispensed. The film tube, while enclosing the passage and hermetically sealing the contaminated area from the uncontaminated area, is stored in a cassette, in particular stacked or rolled, to permit a continuous tube removal for several transfer operations of protective covers. 
     The protective cover is preferably designed to be peelable at least at its penetrating end having layered sheeting parts. The sheetings, which have been sealed against each other in this respect, are then pulled away from each other to open the passage opening. 
     A coverall for the transfer of a person sealed against the environment can be formed by the protective cover. After pulling the at least one peelable sheeting or its sheeting parts apart, the coverall can be put on or taken off by opening the passage opening. 
     Particularly advantageously, the closed sheeting is rolled up and stored in a preferably closable breast pocket of the coverall after the coverall has been put on and the associated passage opening has been closed by placing the peelable sheeting or parts of the sheeting against each other to form the penetrating end of the protective cover. 
     For an environmentally sealed transfer process of objects contained in a protective cover, the docking area can be installed in front of a manipulator room, in which work can be performed, preferably from the outside wearing gloves. The docking area is separated from the manipulator room by an airlock. 
     With particular advantage the docking area in front of the manipulator room can be designed as an airlock chamber, in conjunction with the cassette for the film tube and at least one sealing device. 
     Advantageously, the individual sealing device can be formed by two sealing jaws, which can be moved against each other and which preferably simultaneously permit a fusing or sealing of the film material. In addition to the formed joining seam, simultaneously the sealing jaws may perform a cutting or severing of the film material. 
     Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the drawings, discloses preferred embodiments of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings that form a part of this disclosure: 
         FIG. 1  is a highly schematically simplified and sketched perspective view of a protective cover in the form of a coverall and a part of the outer wall of a protective space having a docking area for the protective cover located thereon; 
         FIG. 2  a functional side view sketch, which is even more simplified than  FIG. 1 , of the docking area of the outer wall having a transfer passage closed by the safety cover and a connecting end of the protective cover before it is joined to the receiving end of the safety cover; 
         FIG. 3  is a side view sketch of the docking area of  FIG. 2 , wherein the joined state of the ends of both covers is shown; 
         FIGS. 4 and 5  are side view sketches of the docking area of  FIG. 2  wherein the state of joining and closing of the joined ends of the covers by cut-off sealing and the cutting off of protruding ends of the covers, respectively, are shown; 
         FIG. 6  is a side view sketched of the docking area of  FIG. 2  of the process of forming an opening between the joined ends of the covers; 
         FIG. 7  is a side view sketch of the docking area of  FIG. 2  of the state after the protective cover has been inverted and before the opening is closed; 
         FIG. 8  is a side view sketch of the docking area of  FIG. 7  with a severed, closed protective cover; 
         FIG. 9  is a side view sketch of the docking area with the open protective cover sheathed in the safety cover; 
         FIG. 10  is a side view sketch of the docking area of  FIG. 9  with a safety cover closed by cutting and sealing; 
         FIG. 11  is a side view sketch of the docking area with the cut protective cover sheathed by the safety cover; and 
         FIG. 12  is schematically simplified, side view in section of an airlock chamber forming a docking area installed in front of a manipulator room. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 1 to 11 , the invention is illustrated based on examples in which a protective cover  2 , in the form of a coverall, is formed from sealable sheetings. The protective cover  2  forming the coverall has a passage opening to be put on or taken off by a person  4 , which passage opening is formed by two layered sheeting parts  6  and  8 . Sheeting parts  6  and  8  are sealed in a peelable manner at the free end  10  such that they can be pulled apart to open the passage opening. When the passage opening is closed, hermetic enclosure protects the person  4  against external contamination. A docking area  16  having a passageway  18  is provided for the safe transfer of the person  4 , who is located in a contaminated area  12  in  FIG. 1 , such as the infection or quarantine station of a hospital, to a protective space protected against contamination, of which only part of its outer wall  14  is shown in  FIG. 1 . 
       FIGS. 1 to 5  illustrate the docking process and the creation of a connection between the protective cover  2  and a safety cover  20  sealed against the environment. Before docking, the sheeting parts  6  and  8 , which form the peelable sealed passage opening  10  of the coverall at the free end  10 , are folded and rolled up in a sealable breast pocket  22  of the coverall. From pocket  22 , sheeting parts  6  and  8  can be pulled out for the docking procedure and brought into the position shown in  FIGS. 1 and 2 . The safety cover  20  is formed of a tube of sealable film material. The closed bottom  24  of safety cover  20  forms a hermetic seal of a passage  18 , which is intended for the transfer in the outer wall  14 . The protective cover  2  then separates the contaminated area  12  from an uncontaminated area. The open end of the tube forming the safety cover  20 , opposite from the bottom  24 , is stored, when rolled up, in a cassette  26  surrounding the edge of the transfer passage  18  of the outer wall  14 . The protective cover  2  in  FIG. 2  can be pulled out to the right from the hose store and is available from the store for several transfer operations.  FIG. 2  shows that the safety cover  20  is pulled slightly to the right for the docking and connecting procedure such that the penetrating end  10  of the protective cover  2  can be accommodated in a receiving end  28  of the safety cover  20  as shown in  FIG. 3 , where the adjacent sheeting sections  6  and  8  of the protective cover  2  are situated between sheeting sections  30  and  32  of the safety cover  20 .  FIG. 4  shows the subsequent sealing of the adjacent sheeting parts. This sealing is done by cutting and sealing using movable sealing jaws  34 . As shown in  FIGS. 4 and 5 , a protruding end piece  36  is severed and disposed of. Sealing bars known as sealing jaws  34  are provided for cut and seal processes, which sealing bars extend over the entire width of the hoses of the covers  2 ,  20  to be sealed. Such sealing bars for electrical heat impulse sealing are available, for instance, from JOKE Folienschweißtechnik GmbH, Asselborner Weg 14 bis 16, DE 51429 Bergisch Gladbach. 
       FIG. 6  illustrates the subsequent stage of forming a passage opening  40  by peeling, i.e. lifting the sheeting parts  6  and  8  from each other. When the opening  40  has been formed, the protective cover  2  can be inverted across the opening  40 , such that the inside of the protective cover  2  is turned inside out and in that way the contents of the protective cover  2 , i.e. when the protective cover  2  is formed as a coverall, the person  4 , is transferred out to the clean side behind the outer wall  14 . As  FIGS. 7 and 8  show, the inverted protective cover  2  is closed and severed from the safety cover  20  by a cut and seal process, as it is also performed in  FIG. 4  using the sealing jaws  34 . While in  FIGS. 4 and 5  the end piece  36  is produced as severed waste, the closed protective cover  2  with the contaminated interior  42  is now severed for waste disposal, see  FIG. 8 . The person to be protected against contamination can, in reverse order from the described, basically also enter a contaminated room via the corresponding passage opening  18  into the coverall and detach from the docking area  16  accordingly. However, it is also possible to put on the coverall in a normal airlock area before entering the contaminated room via a separate airlock entrance. 
       FIGS. 9 to 11  illustrate a variant in which, starting from the state of  FIG. 6  where the opening  40  is formed, the protective cover  2  is not turned over, but is pulled through the transfer passage  18  of the outer wall  14  in the direction indicated by the arrow  44  in  FIG. 9 . The safety cover  20  connected to the protective cover  2  at the sealing point  38  is pulled out as well, and thus, forms a sheathing  46  of the protective cover  2 . By closing the sheathing  46  by the sealing jaws  34  performing a cut and seal process, a contaminated intermediate space  48  is formed between the protective cover  2  and the sheathing  46  as a closed area, as shown in  FIGS. 10 and 11 , such that the separate, closed unit can be disposed of as shown in  FIG. 11 . The coverall is then taken off via the opening left open at the front (not to scale). 
       FIG. 12  shows an example, in which the docking area  16  is formed by an airlock chamber  50 , which is installed in front of a manipulator room (not shown), of which only a partition  52  between the airlock chamber and the manipulator room is indicated. In the manipulator room, which forms a clean room or sterile room, located to the right of the partition  52  in  FIG. 12 , work can be performed from the outside by slipping into gloves as per usual.  FIG. 12  shows the docking procedure for the contamination-free transfer of the protective cover  2  from a contaminated area  12  through the airlock chamber  50  into the manipulator room. Here the protective cover  2  forms the hermetically sealed packaging for objects  54 . In the same way as shown in  FIG. 3 , the peelably sealed penetrating end  10  of the protective cover  2  is inserted into the receiving end  28  of the safety cover  20  and is peelably sealed in the same way as shown in  FIG. 4  by the sealing jaws  34 . Because the sealing point is located within the enclosed area of the airlock chamber  50 , which is connected to the manipulator room as the clean room of the airlock chamber  50 , the sealing jaws  34  are arranged outside an elastically yielding partition wall  54   a  enclosing this clean room. The partition wall  54   a  wall is formed, for instance, by a tubular silicone layer, the flexibility of which permits the sealing jaws  34  to be moved towards each other from the outside for the purpose of cutting and sealing. After the sealing process, in which the adjacent sheeting parts of the protective cover  2  and the safety cover  20  are peelably sealed in the same way as shown in  FIG. 4 , the protective cover  2  is pulled through in the direction of the arrow  44  and thereby sheathed by the safety cover  20 . As shown in  FIG. 9  during the corresponding pulling-through process of the protective cover  2 , the protective cover is provided with the sheathing  46 . At the end  56 , which is pulled into the airlock chamber  50  in the direction of the arrow  44 , the same cutting and sealing operation as shown in  FIGS. 10 and 11  can now be performed for the sheathed unit. Because the contaminated interspace  48  located on the outside of the protective cover  2  is hermetically sealed by the sheathing  46 , the objects  54  in the manipulator chamber can be removed after the passage opening  40  has been formed by peeling the sealing point at the penetrating and receiving ends  10  and  28 , respectively. 
     While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the claims.