US 3051163 A
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Description (OCR text may contain errors)
Aug. 28, 1962 P. c. TREXLER ISOLATING DEVICE 2 Sheets-Sheet 1 Filed May 1, 1957 INVENTOR. P/r/z /P 6? 7kx4 2.
BY M C. 7 W ATTOEA/EX Aug. 28, 1962 P. c. TREXLER ISOLATING DEVICE 2 Sheets-$heet 2 Filed May 1, 1957 5 1' E 5 I I 3? q ,1 IIIIIII-VIILUII I NVENTOR. F/afi. PH/L/P C. 7fea 5e.
3&5 1,163 Patented Aug. 28, 1962 3,051,163 ISOLATING DEVICE Philip C. Trexler, Niles, Mich, assignor to University of Notre Dame du Lac, Notre Dame, Ind., a corporation of Indiana Filed May 1, 1957, Ser. No. 656,396 10 Claims. (Cl. 128-1) This invention relates to improvements in isolating devices, and more particularly to a device providing an enclosure for use to confine contamination while experiments and tests involving contamination of test specimens are being made, or to exclude contamination from a space within which tests and experiments are conducted. Contamination, as herein mentioned, may be biological or radiological or chemical.
The primary object of the invention is to provide a device of this character which is transparent to permit full visibility thereof and of contents thereof, which is inexpensive, and which is light in weight.
A further object is to provide a device of this character which is collapsible and which can be erected in a place of use quickly and easily and with a minimum requirement for tools, so that the device can be used easily in disaster areas and other temporary locations where it is desired to conduct biological tests or other operations, such as the growth of cultures for vaccines and like purposes.
A further object is to provide a device of this character having a rigid collapsible frame to which is supportingly secured an enclosure formed of film material which is of light weight and flexible character.
A further object is to provide a device of this character including an enclosure having walls formed of plastic film, with novel means for detachably mounting gloves and sleeves in apertures thereinin sealed relation and without danger of damaging the plastic film or for mounting movable parts to extend through the film and into the device.
A further object is to provide a device of this character having walls formed of plastic film which can be readily tested for leaks by the electrostatic method.
A further object is to provide a device of this character having a metal frame and metal glove-mounting rings which are so protected from corrosive atmospheric conditions within the chamber by the film material forming the chamber as to be completely free from corrosion.
In the drawings:
FIG. 1 is a perspective view illustrating one form of this device;
FIG. 2 is a fragmentary vertical sectional view taken on line 2-2 of FIG. 1;
FIG. 3 is a fragmentary horizontal sectional view taken on line 3-3 of FIG. 1;
FIG. 4 is a detail sectional view taken on line 44 of FIG. 1;
FIG. 5 is a vertical sectional view taken on line 5-5 of FIG. 1;
FIG. 6 is a detail sectional view taken on line 66 of FIG. 5;
FIG. 7 is a fragmentary face view illustrating the connection between a drawbolt and a mounting bar, as viewed from the left in FIG. 5;
'FIG. 8 is a schematic view illustrating the manner employed to electrostatically test the device for the presence of leaks;
FIG. 9 is a sectional view illustrating a modification of the invention; and
FIG. 10 is a sectional view illustrating a modification of the invention useful when the enclosure is to confine air under positive pressure.
Referring to the drawings, and particularly to FIGS.
1 to 7 which illustrate an embodiment of the invention particularly suitable for confining sub-atmospheric pressures, the numeral 10 designates the side walls of a sealed chamber or enclosure which also has a top wall or walls 12, end walls 14, and a bottom wall 16. The walls are continuously marginally and sealingly cemented together to define an enclosure or chamber within which biological or other specimens can be treated, raised, tested or ma nipulated under controlled conditions in which pressure is controlled. The walls 10, 12, 14 and 16 are preferably formed of flexible sheet material, such as a plastic film.
A frame, preferably of collapsible character and rigid skeleton construction, may be provided to mount and support the chamber. The frame will preferably comprise a pair of end structures which are interconnected by longitudinal bars, the connection of the parts preferably being detachable, although the frame structure may be permanently assembled c-r erected and not collapsible. Each of the frame end structures preferably includes upright members 20, bottom member 22., converging upper members 24, and intermediate transverse member 26. The members 20, 22, 24- and 26 are preferably formed of metal tubing which is of rigid character and may be assembled and connected in any manner found suitable. As here shown in FIG. 1, the various parts 20, 22, 24, 26 are formed separately and are interconnected by fittings 28, each of which joins together the end frame parts cooperating therewith in a substantially common plane. Each of the fittings includes a socket portion projecting substantially perpendicularly to the plane of the end frame and adapted to receive, and preferably detachably secure, an end portion of a longitudinally extending frame member 30, of which five are provided in the construction of the shape and contour illustrated in FIG. 1. It will be understood that the end frames at the two ends of the device are preferably similar and are preassembled so that the composite or complete frame may be erected therefrom by the simple expedient of connecting the longitudinal frame members 30 to the end frames.
The plastic film of which the walls 10, 12, 14 and 16 are formed may be of any type found suitable. Thus the film may be of the vinyl type or of the polyester type. The film may be of any thickness found suitable and preferably will be of a thickness in the range from .002 of an inch to .015 of an inch or possibly more. The film is preferably transparent and flexible and may be chosen of a type to possess desired vapor and moisture transmission characteristics. The film selected will depend upon the service to which the device is to be put, and in some such services air and moisture impervious film may be desired, while in other services the film selected may be moisture pervious but impervious to air.
The (film is preferably supported upon the frame in the manner best illustrated in FIGS. 2 and 3. Thus the side walls 10, the top walls 12, and the bottom wall 16 are preferably formed from a single endless belt or strip of the plastic material which is looped at 32 at proper locations to fit around the longitudinal frame members 30 by means of longitudinal seals thereof at 34, as illustrated in FIG. 2. The longitudinal seals 34 may be formed by cohering contacting folds of the film by heat and pressure, or the contacting folds of the film may be cemented or otherwise adhered. It is important that the adhesion at 34 be continuous so as to provide a seal between the adjacent wall portions 10, 12 and 16, as illustrated in FIG. 2, and between the interior of each loop and the interior of the chamber. The end walls 14 are marginally continuously cohered or adhered to the Walls 10, 12 and 16 at 36, as illustrated in FIG. 3, as by the use of cement, heat sealing apparatus or any other means found suitable. As shown in FIGS. 1 and 3, the margin w) 36 will preferably extend adjacent to but spaced from the adjacent end frame members 20, 22, 24 and 26. The size of the plastic parts will preferably be such that walls 10,- 12, 14 and 16 will have the desired degree of tautness when applied over the frame.
In order to work with an manipulate speciments contained within the enclosure, which specimens may be animals, bacteria cultures, plants or any other types of specimens under test, it is necessary for the operator to be able to reach into the interior of the enclosure without danger of destroying or altering the desired atmospheric condition within the enclosure. Long flexible rubber gloves 40 having their open ends marginally sealed at openings in the walls of the enclosure, accomplish this access. The means by which such gloves are mounted with a sealed joint at the flexible film walls of the enclosure may be of the type illustrated in FIG. 4. Thus a rigid metal ring, such as an aluminum ring 42, located at the outer face of the film wall within which the opening 44 is formed, cooperates with a second rigid clamping ring 46 located at the inner face of the wall 10. The two rings are secured together at spaced points by securing members 48. The inner ring 46 preferably has a circumferential groove 50 in the face thereof confronting the outer ring 42 and located in outwardly spaced relation to the securing members 48 to receive the bead ring 52 upon the free end of the sleeve portion 54 of the glove 40. The sleeve portion 54 is preferably of a normal circumferential dimension less than the outer circumferential dimension of ring 46 and is stretched or extended around the outer periphery of the inner ring 46 in a position with its head ring 52 seated in the groove 50. Thus a portion 56 of the sleeve adjacent the bead ring 52 is clamped in continuous sealing face contact with the film wall of the enclosure at the outer marginal portions of the rings 42 and 46 to effect a continuous seal around the opening 44 in the film wall 10.
If it is desired to withdraw the glove 40 for inspection, as illustrated at the left in FIG. 1 and in full lines in FIG. 4, the sleeve is passed around the inner ring 46 and thence through the opening therein and through the outer ring 42. Observe that the flexible glove, which is preferably formed of rubber, serves as a means to protect the metal rings 46 and 42 from exposure to the atmosphere within the enclosure at all times, so that if a corrosive atmosphere is contained therein it cannot attack the metal rings. The same protection against corrosion is provided by the seals 34 and 36 of the film walls with respect to the metal frame structure. Removal of the gloves for replacement is simple inasmuch as the securing members 48 can be manipulated easily from the exterior of the device to permit separation of rings 42, 46 for release of the glove 40 and application of a new glove thereto, followed by reassembly of the structure.
In the event it is desired to maintain a controlled atmospheric condition within the enclosure, conduits may be connected in a sealed manner to supply air and steam or other fluids to the enclosure and to discharge the same from the enclosure. A sealed joint for such a conduit is illustrated in FIG. 9, wherein the closure wall has been designated 10 and is gripped around an opening 60 therein by an outer ring 62 and an inner ring 64. The outer ring 62 preferably includes a projecting neck portion 66 which is internally screw-threaded for connection with a conduit 68. Securing members 70 connect the rings 62 and 64 to clamp the wall 10 around the opening 60 and, if desired, a gasket ring 72 may be provided to facilitate this seal. It will be understood that the construction shown in FIG. 9 may be used for other pur- 7 poses, such as a journal for a rotating or reciprocating shaft, by constructing the rings 62 and 64 with bore-s to serve as journals.
It is necessary in some uses of the apparatus to provide means for access thereto for the purpose of introducing or withdrawing material, or for connection thereof to other enclosures, to permit transfer of material between connected enclosures. This necessitates the provision of a releasable closure for an opening in the device which may provide access to atmosphere or may lead to an autoclave, a tube leading to another enclosure, or the like. One manner in which this may be accomplished is illustr-ated in FJGS. 1 and 5.
Assuming that the access opening is to be formed in the end wall 14, the part of the frame adjacent to that end wall will include a rigid portion 80, such as a ring, secured by members 82 to the adjacent parts of the frame structure, as at the members 20. The ring and the members 82 may be formed of metal tubing or any other suitable material, and the ring 80 will be positioned substantially concentrically with the access opening in the end wall 14. Drawbolts 84 pass freely through openings in the ring 80 and also through openings 86 in the film wall 14. A sealed connection between the shank of each drawbolt 84 and the film wall is provided, as by means of an elongated flexible plastic sleeve 88 having a continuous sealed circumferential connection at one end with the film wall 14 and a continuous sealed circumferential connection with the shank of 'drawbolt 84 at its opposite end. The drawbolt 84 preferably has an enlarged head 90 at its inner end and mounts a nut 92, such as a thumb nut, at its outer end. Two or more drawbolts are provided and serve as means to position a crossbar or spider member 94, the ends of which are preferably slotted at 96, as illustrated in FIG. 7, for readily detachable con nection with the d'rawbolt.
The crossbar 94 has a flexible connection with a closure plate 98 adapted to seal the access opening. This connection is preferably effected by a body of rubber or other flexible material 100 anchored to the crossbar 94 and the closure plate 98 as by the imbedding therein of studs 102 carried by said members 94 and 98 as illustrated in FIG. 6.
The access opening is outlined by an outer ring 104 and an inner ring 106 clamping there'between the portion of the enclosure wall at the margin of the opening. The rings may also clamp in sealing face engagement with the wall of the enclosure around the access opening one end of a flexible sleeve 108 which may be formed of rubber or plastic material. In the construction shown, the sleeve 108 passes through the opening in the rings 104 and 106, thence around the inner ring 106 and its end margin extends between the rings 104 and 106. An annular pad 110 of sponge rubber or other compressible or yieldable material may be provided at the inner face of the inner ring 106. A tubular member 112 is shown in FIGS. 1 and 5 which may constitute either a connecting tube leading to a similar enclosure unit or an autoclave housing which may mount a removable closure (not shown) at its free outer end as well understood in the art and as generally exemplified in 'Reyniers' Patent No. 2,244,082, dated June 3, 1941. The connecting member is preferably in the nature of -a rigid metal tube 112 having a circumferentially sealed connection with the outer end of sleeve 108. It will be understood, however, that the members 108 and 112 are not necessary in each instance and that they may be omitted if desired. In any event, the access opening is sealed by the closure plate 98 which marginally continuously sealingly contacts either the inner ring 106, its facing 110 or the member '108.
It will be observed that the closure 98 is manipulated from the exterior of the device by manipulating the nuts 92 either to position the crossbar 9'4 and the closure plate 98 for sealing engagement of closure 98 will the interior structure outlining the margin .of the access opening, or to release said draw-bolts to permit opening movement of the closure plate 98 relative to the structure outlining the access opening. The members 88 which seal the drawbolts are preferably slack in the sealed or closed position of the parts so that endwise movement of the drawbolts 84 in an inward direction may be accomplished without destroying the seal. It will be apparent that when the drawbolts have been loosened, an operator may reach through a glove 40 and the crossbar 94 may be disengaged from the drawbolts, thus completely freeing the door or closure 98 carried thereby for movement relative to the enclosure part adjacent to the access opening to a position permitting free access through tubular memher 112 to the interior of the structure. It will be understood, of course, that closure 98 may be carried by the crossbar 94 in any other manner found suitable and not necessarily requiring release of the crossbar from the drawbolts to move the closure member to a position clear of the access opening.
The device lends itself particularly to testing for leaks therein by an electrostatic method, such as the method now commonly used in testing electric linemens gloves. One such method is illustrated in FIG. 8, wherein an electrolyte is sprayed to cover the interior and exterior surfaces of the film walls of the enclosure. One electrolyte which may be employed for this purpose constitutes a ten percent calcium chloride solution containing a detergent as a wetting agent. The electrolyte coatings are designated 120 and 122 in FIG. 8. An insulated electrode will be passed through an opening in the plastic film prior to the application of the electrolyte, said electrode preferably constituting an insulated or sheathed portion 124 which is cemented and sealed to the film wall 10. A bared end 126 of the electrode is then adhered to the film at its inner surface in such a manner that it will have electrical contact with the electrolyte 120 at the inner faceof the film wall. A second electrode 128, such as a wire having a bared end portion, is adhered to the film 10 at the outer face thereof in such a manner that it will have electrical connection with the etxernal electrolyte coating 122. A testing circuit as illustrated in FIG. 8 is provided within which a meter 130 is connected, the same preferably being a milliammeter. A transformer 132 may provide connection with a source of current, and the electrode 128 will preferably be grounded.
In conducting the test after the electrolyte has been sprayed on the interior and exterior surfaces of the enclosure to establish electric connection with the electrodes 126 and 128, the procedure is as follows: An electrical current is first applied to the circuit at low voltage. The reading of the milliammeter 130 is then observed to ascertain Whether or not any leakage or flow of current occurs in the circuit. It will 'be apparent that such leakage may occur if any openings exist in the film walls of the closure which permit the two coatings 120 and 122 to merge and thus close the circuit. If the initial test at low voltage indicates no leakage or fiow of current, the voltage is increased progressively until it reaches a desired maximum value, for example, approximately 5,000 volts. If no leakage or current flow is indicated by the milliammeter under those conditions of applied electrical potential, the operator is assured that the film enclosure is completely sealed and that the device is safe for use to maintain a sterile atmosphere, to contain and confine a contaminated atmosphere, or to maintain a desired pressure condition.
It will be evident from the foregoing that the device is characterized by low cost as compared to the cost of apparatus formed of metal or other materials. It is further characterized by the inherent transparency of the film material which permits vision of the contents of the enclosure at any time and eliminates the need for provision of sight openings in the device. The collapsibility of the device renders it readily portable and enables its use at locations of disasters or other emergency conditions. Also, the collapsibility .of the film enclosure permits enclosures formed of some films to be folded for insertion into an autoclave for sterilization thereof. The device possesses a wide range of flexibility with respect to the uses to which it may be put and the conditions under which it is used, assuming, of course, that materials are selected which will meet those conditions. Thus in some instances where a sterile condition is desired to be maintained within the enclosure, the film must be selected of a material which is impervious to both air and moisture. In some instances, where contamination is to be confined, it may be immaterial whether the structure is moisture pervious but important that it be impervious to air.
In order to minimize the strain on the structure at the points at which connections for gloves or closures or the like are provided, it is desirable to make the rings which clamp the film around the openings of a light weight metal, such as aluminum. These rings must in each instance, however, be sufficiently rigid to continuously marginally clamp and seal the film when drawn together. Furthermore, the structure at all joints and connections must be arranged to distribute uniformly and radially the stresses of the connection and the rings and other parts or, in the case of the closure 98, must be constructed to transmit stresses to the supporting frame to protect the plastic film of which the wall is formed.
In cases where the enclosure is to contain air under positive pressure and hence be inflated, so that collapse of the flexible walls is not a problem, the frame may be omitted, or a simpler connection between the enclosure and a frame or support than above described may be provided. In such cases it may be desirable to insert a rigid panel in the enclosure as shown in FIG. 10, to assist in controlling the shape of the inflated enclosure and to hold it in desired location.
While the preferred embodiments of the invention have been illustrated and described, it will be understood that changes in the construction may be made within the scope of the appended claims without departing from the spirit of the invention.
1. An isolating device comprising an enclosure formed of flexible film material, said enclosure having an opening, a flexible access glove having a sleeve portion, inner and outer rigid registering rings, securing means drawing together said rings for clamping said film material therebetween continuously around said opening, said glove sleeve extending around the inner ring with its open end portion inturned and clamped between said rings, said glove having elasticity to accommodate flat positioning of said inturned end portion in continuous sealed wrinkle-free engagement with said film material and with the clamping surface of said outer ring around said opening outwardly of said securing means.
2. An isolating device as defined in claim 1, wherein the open end of the internal portion of said sleeve is defined by a bead ring, and the clamping face of said inner ring has an endless bead-receiving groove therein.
3. An isolating device comprising an enclosure formed of flexible film material, said enclosure having an opening, a pair of registering rings having complementary cooperating film-clamping surfaces confronting opposite faces of said film material continuously around said opening and securing means connecting inner portions of said rings to draw them into film-clamping relation.
4. An isolating device comprising a frame, an enclosure supported by said frame and formed of flexible film material, said enclosure having an opening, a rigid ring unit clamping said film concentrically with and continuously and uniformly surrounding said opening and consisting of concentric rings at opposite sides of said film and draw bolts connecting said rings at their inner margins to draw said rings into clamping relation to said film.
5. An isolating device as defined in claim 4, and a removable closure spanning said opening, and means releasably supporting said closure in continuous sealing relation to said ring unit.
6. An isolating device comprising a support, an enclosure connected to said support and formed of flexible film material, said enclosure having an opening, a rigid ring unit carried by said film concentrically with and surrounding said opening, a closure spanning said opening, and
. means carried by said support and releasably supporting said closure in continuous sealing relation to said ring unit, said ring unit including an annular yielding member engaged continuously by the marginal portion of said closure.
8. An isolating device comprising a support, an enclosure connected to said support and formed of flexible film material, said enclosure having an opening, a rigid ring unit carried by said film concentrically with and surrounding said opening, a closure spanning said opening, means carried by said support and releasably supporting said closure in continuous sealing relation to said ring unit, said closure being located within said enclosure and said closure supporting means including a drawbolt extending through an opening in said enclosure, and a flexible elongated tubular member encircling and sealed to said bolt at one end and sealed around said last named opening at its opposite end.
9. An isolating device as defined in claim 1, wherein said enclosure is substantially air tight and electrolytic coatings cover the inner and outer surfaces of said enclosure, means for adhering conductors to the inner and outer surfaces of said enclosure in contact with said coatings,
means connecting said conductors in an electric circuit.
normally broken by said coated film material positioned in the atmosphere, means for electrically charging said circuit, and means for measuring flow of electrical current in said circuit.
10. An isolating device as defined in claim 1, wherein said enclosure is substantially air tight and electrolytic coatings cover the inner and outer surfaces of said enclosure, conductors adhering to the inner and outer surfaces of said enclosure in contact with said coatings, means for imposing an electric potential on said conductors while said enclosure is positioned in the atmosphere, and means for measuring flow of electrical current between said coatings and conductors.
References (Iited in the file of this patent UNITED STATES PATENTS 2,243,999 Chapple June 3, 1941 2,496,175 Perry Jan. 31., 1950 2,497,832 Fairlamb Feb. 14, 1950 2,503,992 Becker Apr. 11, 1950 2,624,333 Dixon et al. Jan. 6, 1953 2,646,057 Blanchard July 21, 1953 2,652,047 Luck et al Sept. 15, 1953 2,659,364 Bruckman Nov. 17, 1953 2,664,890 Wallace Jan. 5, 1954 2,695,608 Gibbon Nov. 30, 1954 2,702,546 Gilroy et al Feb. 22, 1955 2,778,362 Pollock et a1 Jan. 22, 1957 2,786,740 Taylor et a1 Mar. 26, 1957 2,810,390 Wallace Oct. 22, 1957 2,811,164 Ames Oct. 29, 1957 2,822,803 Huxley Feb. 11, 1958