Abstract:
A closure mechanism and seating controls in combination with use with a hyperbaric chamber are described. The closure mechanism in combination with a hyperbaric chamber includes a door opening, a chamber door with dimensions larger than the door opening, a ring of sealing material secured to either the outer surface of the door or the inner surface of the chamber, a means for positioning the door adjacent the door opening and a means for pressurizing the chamber to effect a seal. The closure mechanism also includes an upper rail and pivoting carriers that may slide along the rail and a lower track mounted adjacent the floor and door guides that may slide within the track. The carriers and door guides are mounted to the interior surface of the door. The door and chamber walls may be flat, or curved in one or more planes. A locking mechanism is provided that employs a sliding wedge-shaped member that engages a retaining bar to secure the door in a closed position and a stop for securing the door in an open position. The seating controls in combination with a hyperbaric chamber provide means to swivel a seat support bracket about a base secured to the chamber floor and means rotate a seat about the bracket so that a patient can be easily and comfortably positioned within the chamber. Means are provided to lock the seat in a variety of positions including inclining the seat back.

Description:
FIELD OF INVENTION 
     The invention pertains to accessories in combination with pressure vessels. More particularly, the invention relates to closure mechanisms and seating controls in combination with a hyperbaric chamber. 
     BACKGROUND OF THE INVENTION 
     Various types of closure mechanisms have been developed in combination with hyperbaric chambers; incorporating a number of different technologies. U.S. Pat. No. 5,327,904 issued to Hannum employs a transparent rectangular door sliding on a pair of rods to seal the chamber. Hannum also discloses a sliding seat arrangement that incorporates a pair of rails to permit the seat to slide forward and back within the chamber. 
     U.S. Pat. No. 5,398,678 issued to Gamow, incorporates an airtight zipper attached to an inflatable hyperbaric chamber to provide ingress and egress for the chamber. U.S. Pat. No. 4,573,286, issued to Farvel et al. discloses a device for suspending and guiding a movable panel. This invention incorporates a tubular channel with a ball-bearing mounted spherical roller positioned inside of the channel from which the panel is suspended. U.S. Pat. No. 5,433,334 issued to Reneau employs an outwardly hinged door with rotary locking mechanism to secure the opening of a hyperbaric chamber. U.S. Pat. No. 5,857,739 issued to Smith describes a swivel-recliner chair providing a variety of adjustment mechanisms. 
     While other variations exist, the above-described designs for closure and seating controls in combination with hyperbaric chambers are typical of those encountered in the prior art. It is an objective of the present invention to provide a reliable means for sealing a hyperbaric chamber opening. It is a further objective to provide a closing mechanism that is simple to operate and that provides for easy entrance and egress from the hyperbaric chamber. It is a further objective of the invention to provide a closing mechanism that may be easily manufactured, at a reasonable cost and with the required precision. It is yet a further objective that the closing mechanism be easily adjustable for wear at the sealing surfaces. It is still another objective of the invention to provide a seat control mechanism that allows for convenient and precise positioning of the patient within the chamber. It is yet another objective to provide a seat control that may be easily locked and unlocked in a variety of positions. 
     While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified. 
     SUMMARY OF THE INVENTION 
     The present invention addresses all of the deficiencies of prior art closure and seating control inventions in combination with hyperbaric chambers and satisfies all of the objectives described above. 
     A closure mechanism in combination with a hyperbaric chamber providing the desired features may be constructed from the following components. A floor, a ceiling, a surrounding wall sealably joined to said floor and said ceiling an inner surface, an outer surface and a door opening having first predetermined dimensions. A ring of malleable sealing material is provided. The sealing material is located on the inner surface of the chamber at a first predetermined distance from the door opening. A means is provided for affixing the sealing material to the inner surface of the chamber. 
     A hyperbaric chamber door is provided. The door has an inner surface, an outer surface, an upper end and a lower end. The door has second predetermined dimensions that are larger than the first dimensions such that the perimeter of the door extends beyond the ring of the sealing material. Means are provided for positioning the door within the chamber in a first position such that the outer surface of the door abuts the sealing material and in a second position permitting entry into the chamber. Means are provided for pressurizing the chamber. 
     When the door is located in the first position and the chamber is pressurized, the door will be urged against the sealing material. This action will seal the outer surface of the chamber door to the inner surface of the chamber and permit the pressure within the chamber to be increased above ambient. 
     In a variant of the invention, the door opening of the hyperbaric chamber is curved in at least one plane and the chamber door is curved in at least one plane such that the door may be sealed in position adjacent the door opening. 
     In another variant, the hyperbaric chamber door has an inner surface, an outer surface, an upper end and a lower end and has second predetermined dimensions. The second dimensions are larger than the first dimensions such that the perimeter of the door extends beyond the chamber door opening. 
     A ring of malleable sealing material is provided. The sealing material is located on the outer surface of the chamber door at a second predetermined distance from the door perimeter. A means is provided for affixing the sealing material to the outer surface of the door. Means are provided for positioning the door within the chamber in a first position such that the sealing material abuts the inner surface of the chamber and in a second position permitting entry into the chamber. Means are provided for pressurizing the chamber. 
     When the door is located in the first position and the chamber is pressurized, the door and the affixed sealing material will be urged against the inner surface of the chamber. This action will seal the outer surface of the chamber door to the inner surface of the chamber and permit the pressure within the chamber to be increased above ambient. 
     In a variant on this embodiment, the door opening of the hyperbaric chamber is curved in at least one plane and the chamber door is curved in at least one plane such that the door may be sealably positioned adjacent the door opening. 
     In yet another variant of the invention, means for locking and unlocking the chamber door are provided that include the following components. At least one locking shaft is provided. The shaft has a first end, a second end, a wedge-shaped portion located at the first end and a connecting means located adjacent the second end. The locking shaft is slidably mounted to the inner surface of the chamber door. Means attached to the connecting means of the locking shaft for moving the locking shaft from a first, retracted position to a second extended position are provided. A retaining bar is provided that is mounted to the inner surface of the chamber and located so as to engage the wedge-shaped portion of the locking shaft when the shaft is in the second, extended position and located so as to be disengaged from the wedge-shaped portion when the shaft is in the first, retracted position. 
     When the chamber door is moved to the first position adjacent the door opening and the locking shaft is moved is moved from the first position to the second position, the wedge-shaped portion will bear against the retaining bar. This action urges the door against the inner surface of the chamber and compresses the ring of sealing material to form an airtight seal between the door and the chamber. 
     When the pressure is reduced in the chamber and the locking shaft is moved from the second position to the first position, this action disengages the wedge-shaped portion from the retaining bar. The chamber door may now be moved to the second position to permit entry and exit from the chamber. 
     In still another variant, the means for affixing the sealing material to the inner surface of the chamber includes a groove. The groove is sized and shaped to accept a first, inner portion of the ring of malleable sealing material and located on the inner surface of the hyperbaric chamber at the first predetermined distance from the door opening. Means for attaching the ring of malleable sealing material to the groove are provided. 
     In yet another variant of the invention, the means for affixing the sealing material to the outer surface of the chamber door includes a groove. The groove is sized and shaped to accept a second, outer portion of the ring of malleable sealing material and located on the outer surface of the chamber door at the second predetermined distance from the door perimeter. Means are provided for attaching the ring of malleable sealing material to the groove. 
     In still a further variant, the means for positioning the door within the chamber in a first position such that the outer surface of the door abuts the sealing material and in a second position permitting entry into the chamber further includes an L-shaped lower track. The lower track has a first section and a second section. Each of the sections has a first end and a second end and is located adjacent the floor of the chamber. The first section is substantially parallel to the door opening and the second section extends away from the door opening and into the chamber. 
     First and second lower door guides are provided. The lower guides are affixed to the inner surface of the chamber door adjacent its lower end and are sized, shaped, and located to fit slidably within the lower track. First and second upper carrier rails are provided. Each of the rails has a first end and a second end. The first rail is fixedly attached at its first and second ends to the ceiling of the chamber. The first rail is substantially parallel to door opening and the first section of the lower track. The second rail is fixedly attached at its first and second ends to the ceiling of the chamber. The second rail extends from the second end of the first rail away from the door opening and into the chamber. The second rail is substantially parallel to the second section of the lower track. 
     A first door carrier is provided. The first carrier is rotatably mounted to the inner surface of the chamber door adjacent its upper end. The first carrier is sized, shaped, and located to move slidably along the first rail. A second door carrier is provided. The second carrier is rotatably mounted to the inner surface of the chamber door adjacent its upper end and is sized, shaped, and located to move slidably along the second rail. 
     When the chamber door is located in the first position, the first door guide will be located adjacent the first end of the first section of the lower track and the second door guide will be located adjacent the second end of the first section of the lower track. The first door carrier will be located adjacent the first end of the first upper carrier rail and the second door carrier will be located adjacent the first end of the second upper carrier rail. When the carriers and guides are so positioned, it allows the chamber door to be sealed to the chamber. 
     When the chamber door is located in the second position, the first door guide will be located adjacent the second end of the first section of the lower track and the second door guide will be located adjacent the first end of the second section of the lower track. The first door carrier will be located adjacent the second end of the first upper carrier rail and the second door carrier will be located adjacent the second end of the second upper carrier rail. When the carriers and guides are so positioned, entry into the chamber is possible. 
     In yet a further variant of the invention, the means for positioning the door within the chamber in a first position such that the sealing material abuts the inner surface of the chamber and in a second position permitting entry into the chamber further includes an L-shaped lower track. The lower track has a first section and a second section. Each of the sections has a first end and a second end and is located adjacent the floor of the chamber. The first section is substantially parallel to the door opening and the second section extends away from the door opening and into the chamber. 
     First and second lower door guides are provided. The lower guides are affixed to the inner surface of the chamber door adjacent its lower end and are sized, shaped, and located to fit slidably within the lower track. First and second upper carrier rails are provided. Each of the rails has a first end and a second end. The first rail is fixedly attached at its first and second ends to the ceiling of the chamber. The first rail is substantially parallel to door opening and the first section of the lower track. The second rail is fixedly attached at its first and second ends to the ceiling of the chamber. The second rail extends from the second end of the first rail away from the door opening and into the chamber. The second rail is substantially parallel to the second section of the lower track. 
     A first door carrier is provided. The first carrier is rotatably mounted to the inner surface of the chamber door adjacent its upper end. The first carrier is sized, shaped, and located to move slidably along the first rail. A second door carrier is provided. The second carrier is rotatably mounted to the inner surface of the chamber door adjacent its upper end and is sized, shaped, and located to move slidably along the second rail. 
     When the chamber door is located in the first position, the first door guide will be located adjacent the first end of the first section of the lower track and the second door guide will be located adjacent the second end of the first section of the lower track. The first door carrier will be located adjacent the first end of the first upper carrier rail and the second door carrier will be located adjacent the first end of the second upper carrier rail. When the carriers and guides are so positioned, it allows the chamber door to be sealed to the chamber. 
     When the chamber door is located in the second position, the first door guide will be located adjacent the second end of the first section of the lower track and the second door guide will be located adjacent the first end of the second section of the lower track. The first door carrier will be located adjacent the second end of the first upper carrier rail and the second door carrier will be located adjacent the second end of the second upper carrier rail. When the carriers and guides are so positioned, entry into the chamber is possible. 
     In another variant of the invention, a seat pivoting system in combination with a hyperbaric chamber includes the following components. A hyperbaric chamber is provided. The chamber has a floor, a ceiling, a surrounding wall sealably joined to said floor and said ceiling an inner surface, an outer surface and a door opening having first predetermined dimensions. A base is provided that is fixedly attached to the chamber floor adjacent the door opening. 
     A seat support bracket is provided. The bracket has a first end and a second end and is rotatably mounted at the first end to the base. Means are provided for controlling the rotation of the bracket about the base. A seat-mounting platform is provided. The platform is rotatably mounted to the second end of the bracket. Means are provided for controlling the rotation of the platform about the bracket. A lower seat portion is fixedly attached to the seat-mounting platform. A seat back portion is pivotally mounted to the lower seat portion. Means are provided for adjusting the inclination of the seat back portion with respect to the lower seat portion. In use, the means for controlling the rotation of the bracket about the base is loosened so that the bracket may pivot about the base. The means for controlling the rotation of the platform about the bracket is loosened to permit the seat portions to pivot about second end of the bracket. The seat portions may now extend outwardly toward the chamber door opening with the seat portions facing the door opening to assist a patient to be placed upon the seat. The seat portions may now be pivoted upon the seat-mounting platform to allow a patient to face into the chamber. The seat support bracket may now be pivoted upon the base to center the patient within the chamber; the seat portions and support bracket may be then secured in place. 
     In yet another variant of the invention, the means for locking and unlocking the chamber door includes at least one means for pivotally mounting the retaining bar. The retaining bar is so mounted to provide clearance for the ring of malleable sealing material, the first carrier and the first door guide when moving the chamber door from the second, open position to the first, closed position. 
     In yet a further variant of the invention, at least one means for engaging the wedge-shaped portion of the locking shaft so as to retain the door in the second position is provided. In still a further variant, a doorstop formed of resilient material is provided. The doorstop serves to limit the motion of the door when moving from the second position to the first, closed position. 
     In still another variant, the means for positioning the door within the chamber in a first position such that the outer surface of the door abuts the sealing material and in a second position permitting entry into the chamber further includes a means for pivotally mounting the second end of the first upper carrier rail to the ceiling of the chamber. Means for adjusting the height of the first and second upper carrier rails above the chamber floor are provided. A means for providing sliding support for the first end of the first upper carrier rail is provided. The means permits the first carrier rail to move toward and away from the chamber door opening. 
     A first relief notch is provided. The relief notch is located at the first end of the first section of the L-shaped lower floor track and extends at a right angle to the first section toward the chamber door opening. A second relief notch is provided. This relief notch is located at the second end of the first section of the L-shaped lower floor track and extends from the first end of the second section of the L-shaped track at a right angle to the first section toward the chamber door opening in line with the second track section. 
     When the door is positioned in the first, closed position and the locking shaft is moved to the second, extended position, thereby causing the wedge-shaped portion to engage the retaining bar, the door may move toward the door opening to seal against the opening. 
     In still a further variant, the means for positioning the door within the chamber in a first position such that the sealing material abuts the inner surface of the chamber and in a second position permitting entry into the chamber further includes a means for pivotally mounting the second end of the first upper carrier rail to the ceiling of the chamber. Means for adjusting the height of the first and second upper carrier rails above the chamber floor are provided. A means for providing sliding support for the first end of the first upper carrier rail is provided. The means permits the first carrier rail to move toward and away from the chamber door opening. 
     A first relief notch is provided. The relief notch is located at the first end of the first section of the L-shaped lower floor track and extends at a right angle to the first section toward the chamber door opening. A second relief notch is provided. This relief notch is located at the second end of the first section of the L-shaped lower floor track and extends from the first end of the second section of the L-shaped track at a right angle to the first section toward the chamber door opening in line with the second track section. 
     When the door is positioned in the first, closed position and the locking shaft is moved to the second, extended position, thereby causing the wedge-shaped portion to engage the retaining bar, the door may move toward the door opening to seal against the opening. 
     In a final variant of the invention, the seat pivoting system in combination with a hyperbaric chamber further includes a control member. The control member has a first end and a second end and is rotatably mounted at its first end to the first end of the seat support bracket. The control member is rotatably mounted at its second end to the seat-mounting platform. When the seat support bracket is rotated about the base the seat-mounting platform will rotate so as to maintain the orientation of the lower seat portion and seat back portion to the chamber door opening. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the preferred embodiment of the closure mechanism of the invention in the closed position; 
     FIG. 2 is a perspective view of the FIG. 1 embodiment of the closure mechanism in the open position; 
     FIG. 2 a  is a perspective view of a second embodiment of the closure mechanism attached to a hyperbaric chamber in the open position illustrating a curved chamber door and door opening; 
     FIG. 3 a  is a plan view of the FIG. 2 a  embodiment illustrating the attachment of the seal to the outer surface of the chamber door and the door in a closed position; 
     FIG. 3 b  is a plan view of the FIG. 2 a  embodiment illustrating the attachment of the seal to the outer surface of the chamber door and the door in an open position; 
     FIG. 3 c  is a plan view of the FIG. 1 embodiment illustrating the attachment of the seal to the inner surface of the chamber and the door in a closed position; 
     FIG. 4 is a perspective view of the FIG. 1 embodiment taken from the interior of the chamber and illustrating the upper means for positioning the door within the chamber; 
     FIG. 5 is a perspective view of the FIG. 1 embodiment taken from the interior of the chamber and illustrating the lower means for positioning the door within the chamber; 
     FIG. 6 is a partial cross-sectional side elevation of the first door carrier and first upper carrier rail; 
     FIG. 7 is a cross-sectional end view of the first upper carrier rail and a partial cross-sectional end view of the first door carrier; 
     FIG. 8 is a cross-sectional side elevation of the means for providing sliding support for the first end of the upper carrier rail; 
     FIG. 9 is a side elevational view of the means for locking and unlocking the chamber door; 
     FIG. 10 is a partial enlarged side elevational view of the means for locking and unlocking the chamber door illustrating the locked position; 
     FIG. 11 is a partial enlarged side elevational view of the means for locking and unlocking the chamber door illustrating the unlocked position; 
     FIG. 12 is a perspective view of the seat pivoting system and seat portions in combination with the hyperbaric chamber; and 
     FIG. 13 is a plan view of the seat pivoting in combination with the hyperbaric chamber; 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-5 illustrate a closure mechanism  10  in combination with a hyperbaric chamber  14  providing the desired features. A  14  floor  18 , a ceiling a surrounding wall sealably joined to said floor and said ceiling  22 , an inner surface  26 , an outer surface  30  and a door opening  34  having first predetermined dimensions. As illustrated in FIGS. 2,  3   a ,  3   b  and  3   c , a ring of malleable sealing material  42  is provided. As illustrated in FIG. 3 c , the sealing material  42  is located on the inner surface  26  of the chamber  14  at a first predetermined distance  46  from the door opening  34 . A means  50  is provided for affixing the sealing material  42  to the inner surface  26  of the chamber  14 . 
     As illustrated in FIGS. 3 c ,  4 , and  5 , a hyperbaric chamber door  54  is provided. The door  54  has an inner surface  58 , an outer surface  62 , an upper end  66  and a lower end  70 . The door  54  has second predetermined dimensions that are larger than the first dimensions such that the perimeter  78  of the door  54  extends beyond the ring of the sealing material  42 . Means  82  are provided for positioning the door  54  within the chamber  14  in a first position such that the outer surface  62  of the door  54  abuts the sealing material  42  and in a second position permitting entry into the chamber  14 . Means (not shown) are provided for pressurizing the chamber  14 . 
     When the door  54  is located in the first position and the chamber  14  is pressurized, the door  54  will be urged against the sealing material  42 . This action will seal the outer surface  62  of the chamber door  54  to the inner surface  26  of the chamber  14  and permit the pressure within the chamber  14  to be increased above ambient. 
     In a variant of the invention, also illustrated by FIG. 1, the door opening  34  of the hyperbaric chamber  14  is curved in at least one plane and the chamber door  54  is curved in at least one plane such that the door  54  may be sealed in position adjacent the door opening  34 . 
     In another variant, as illustrated in FIGS. 3 a  and  3   b , the hyperbaric chamber door  54   b  has an inner surface  58   b , an outer surface  62   b , an upper end  66   b  and a lower end  70   b  and has second predetermined dimensions. The second dimensions are larger than the first dimensions such that the perimeter  78   b  of the door  54   b  extends beyond the chamber door opening  34   b.    
     A ring of malleable sealing material  42   b  is provided. The sealing material  42   b  is located on the outer surface  62   b  of the chamber door  54   b  at a second predetermined distance  86  from the door perimeter  78   b . A means  90  is provided for affixing the sealing material  42   b  to the outer surface  62   b  of the door  54   b . Means  82   b  are provided for positioning the door  54   b  within the chamber  14   b  in a first position such that the sealing material  42   b  abuts the inner surface  26   b  of the chamber  14   b  and in a second position permitting entry into the chamber  14   b . Means (not shown) are provided for pressurizing the chamber  14   b.    
     When the door  54   b  is located in the first position and the chamber  14   b  is pressurized, the door  54   b  and the affixed sealing material  42   b  will be urged against the inner surface  26   b  of the chamber  14   b . This action will seal the outer surface  62   b  of the chamber door  54   b  to the inner surface  26   b  of the chamber  14   b  and permit the pressure within the chamber  14   b  to be increased above ambient. 
     In a variant on this embodiment, as illustrated in FIG. 2 a , the door opening  34   a  of the hyperbaric chamber  14   a  is curved in at least one plane and the chamber door  54   a  is curved in at least one plane such that the door  54   a  may be sealably positioned adjacent the door opening  34   a.    
     In yet another variant of the invention, as illustrated in FIGS. 9,  10  and  11 , means  90  for locking and unlocking the chamber door  54   b  are provided that include the following components. At least one locking shaft  94  is provided. The shaft  94  has a first end  98 , a second end  102 , a wedge-shaped portion  106  located at the first end  98  and a connecting means  110  located adjacent the second end  102 . The locking shaft  94  is slidably mounted to the inner surface  58   b  of the chamber door  54   b . Means  114  attached to the connecting means  110  of the locking shaft  94  for moving the locking shaft  94  from a first, retracted position to a second extended position are provided. A retaining bar  118  is provided. The retaining bar  118  is mounted to the inner surface  26   b  of the chamber  14   b . The retaining bar  118  is located so as to engage the wedge-shaped portion  106  of the locking shaft  94  when the shaft  94  is in the second, extended position (FIGS. 9 and 10) and located so as to be disengaged from the wedge-shaped portion  106  when the shaft  94  is in the first, retracted position (FIG.  11 ). 
     When the chamber door  54   b  is moved to the first position adjacent the door opening  34   b  and the locking shaft  94  is moved is moved from the first position to the second position, the wedge-shaped portion  106  will bear against the retaining bar  118 . This action urges the door  54   b  against the inner surface  26   b  of the chamber  14   b  and compresses the ring of sealing material  42   b  to form an airtight seal between the door  54   b  and the chamber  14   b.    
     When the pressure is reduced in the chamber  14   b  and the locking shaft  94  is moved from the second position to the first position, this action disengages the wedge-shaped portion  106  from the retaining bar  118 . The chamber door  54   b  may now be moved to the second position to permit entry and exit from the chamber  14   b.    
     In still another variant, as illustrated in FIG. 3 c , the means  50  for affixing the sealing material  42  to the inner surface  26  of the chamber  14  includes a groove  122 . The groove  122  is sized and shaped to accept a first, inner portion  126  of the ring of malleable sealing material  42  and located on the inner surface  26  of the hyperbaric chamber  14  at the first predetermined distance  46  from the door opening  34 . Means (not shown) for attaching the ring of malleable sealing material  42  to the groove  122  are provided. 
     In yet another variant of the invention, as illustrated in FIGS. 3 a  and  3   b , the means  90  for affixing the sealing material  42   b  to the outer surface  62   b  of the chamber door  54   b  includes a groove  122   b . The groove  122   b  is sized and shaped to accept a second, outer portion  130  of the ring of malleable sealing material  42   b  and located on the outer surface  62   b  of the chamber door  54   b  at the second predetermined distance  86  from the door perimeter  78   b . Means (not shown) are provided for attaching the ring of malleable sealing material  42   b  to the groove  122   b.    
     In still a further variant, as illustrated in FIGS. 4 and 5, the means  82  for positioning the door  54  within the chamber  14  in a first position such that the outer surface  62  of the door  54  abuts the sealing material  42 , and in a second position permitting entry into the chamber  14 , further includes an L-shaped lower track  138 . The lower track  138  has a first section  142  and a second section  146 . Each of the sections  142 ,  146  has a first end  150 ,  154  and a second end  158 ,  162  and is located adjacent the floor  18  of the chamber  14 . The first section  142  is substantially parallel to the door opening  34  and the second section  146  extends away from the door opening  34  and into the chamber  14 . First  166  and second  170  lower door guides are provided. The lower guides  166 ,  170  are affixed to the inner surface  58  of the chamber door  54  adjacent its lower end  70  and are sized, shaped, and located to fit slidably within the lower track  138 . 
     First  174  and second  178  upper carrier rails are provided. Each of the rails  174 ,  178  has a first end  182 ,  186  and a second end  190 ,  194 . The first rail  174  is fixedly attached at its first  182  and second  190  ends to the ceiling  22  of the chamber  14 . The first rail  174  is substantially parallel to door opening  34  and the first section  142  of the lower track  138 . The second rail  178  is fixedly attached at its first  186  and second  194  ends to the ceiling  22  of the chamber  14 . The second rail  178  extends from the second end  190  of the first rail  174  away from the door opening  34  and into the chamber  14 . The second rail  178  is substantially parallel to the second section  146  of the lower track  138 . 
     A first door carrier  198  is provided. The first carrier  198  is rotatably mounted to the inner surface  58  of the chamber door  54  adjacent its upper end  66 . The first carrier  198  is sized, shaped, and located to move slidably along the first rail  174 . A second door carrier  202  is provided. The second carrier  202  is rotatably mounted to the inner surface  58  of the chamber door  54  adjacent its upper end  66  and is sized, shaped, and located to move slidably along the second rail  178 . 
     When the chamber door  54  is located in the first position, the first door guide  166  will be located adjacent the first end  150  of the first section  142  of the lower track  138  and the second door guide  170  will be located adjacent the second end  158  of the first section  142  of the lower track  138 . The first door carrier  198  will be located adjacent the first end  182  of the first upper carrier rail  174  and the second door carrier  202  will be located adjacent the first end  186  of the second upper carrier rail  178 . When the carriers  198 ,  202  and guides  166 ,  170  are so positioned, it allows the chamber door  54  to be sealed to the chamber  14 . 
     When the chamber door  54  is located in the second position, the first door guide  166  will be located adjacent the second end  158  of the first section  142  of the lower track  138  and the second door guide  170  will be located adjacent the first end  154  of the second section  146  of the lower track  138 . The first door carrier  198  will be located adjacent the second end  190  of the first upper carrier rail  174  and the second door carrier  202  will be located adjacent the second end  194  of the second upper carrier rail  178 . When the carriers  198 ,  202  and guides  166 ,  170  are so positioned, entry into the chamber  14  is possible. 
     In yet a further variant of the invention, as illustrated in FIGS. 3 a  and  3   b , the means  82   b  for positioning the door  54   b  within the chamber  14   b  in a first position such that the sealing material  42   b  abuts the inner surface  58   b  of the chamber  14   b  and in a second position permitting entry into the chamber  14   b  further includes an L-shaped lower track  138 . As illustrated in FIG. 5, the lower track  138  has a first section  142  and a second section  146 . Each of the sections  142 ,  146  has a first end  150 ,  154  and a second end  158 ,  162  and is located adjacent the floor  18  of the chamber  14 . The first section  142  is substantially parallel to the door opening  34  and the second section  146  extends away from the door opening  34  and into the chamber  14 . 
     As illustrated in FIG. 4, first  166  and second  170  lower door guides are provided. The lower guides  166 ,  170  are affixed to the inner surface  58  of the chamber door  54  adjacent its lower end  70  and are sized, shaped, and located to fit slidably within the lower track  138 . First  174  and second  178  upper carrier rails are provided. Each of the rails  174 ,  178  has a first end  182 ,  186  and a second end  190 ,  194 . The first rail  174  is fixedly attached at its first  182  and second  190  ends to the ceiling  22  of the chamber  14 . The first rail  174  is substantially parallel to door opening  34  and the first section  142  of the lower track  138 . The second rail  178  is fixedly attached at its first  186  and second  194  ends to the ceiling  22  of the chamber  14 . The second rail  178  extends from the second end  190  of the first rail  174  away from the door opening  34  and into the chamber  14 . The second rail  178  is substantially parallel to the second section  146  of the lower track  138 . 
     As further illustrated in FIGS. 6 and 7, a first door carrier  198  is provided. The first carrier  198  is rotatably mounted to the inner surface  58  of the chamber door  54  adjacent its upper end  66 . The first carrier  198  is sized, shaped, and located to move slidably along the first rail  174 . A second door carrier  202  is provided. The second carrier  202  is rotatably mounted to the inner surface  58  of the chamber door  54  adjacent its upper end  66  and is sized, shaped, and located to move slidably along the second rail  178 . 
     When the chamber door  54  is located in the first position, the first door guide  166  will be located adjacent the first end  150  of the first section  142  of the lower track  138  and the second door guide  170  will be located adjacent the second end  158  of the first section  142  of the lower track  138 . The first door carrier  198  will be located adjacent the first end  182  of the first upper carrier rail  174  and the second door carrier  202  will be located adjacent the first end  186  of the second upper carrier rail  178 . When the carriers  198 ,  202  and guides  166 ,  170  are so positioned, it allows the chamber door  54  to be sealed to the chamber  14 . 
     When the chamber door  54  is located in the second position, the first door guide  166  will be located adjacent the second end  158  of the first section  142  of the lower track  138  and the second door guide  170  will be located adjacent the first end  154  of the second section  146  of the lower track  138 . The first door carrier  198  will be located adjacent the second end  190  of the first upper carrier rail  174  and the second door carrier  202  will be located adjacent the second end  194  of the second upper carrier rail  178 . When the carriers  198 ,  202  and guides  166 ,  170  are so positioned, entry into the chamber  14  is possible. 
     In another variant of the invention, as illustrated in FIGS. 2,  12  and  13 , a seat pivoting system  204  in combination with a hyperbaric chamber includes the following components. A  14  is provided. The chamber has a floor  18 , a ceiling (not shown), a surrounding wall sealably an joined to said floor and said ceiling inner surface  26 , an outer surface  30  and a door opening  34  having first predetermined dimensions. A base  208  is provided that is fixedly attached to the chamber floor  18  adjacent the door opening  34 . 
     A seat support bracket  212  is provided. The bracket  212  has a first end  216  and a second end  220  and is rotatably mounted at the first end  216  to the base  208 . Means  224  are provided for controlling the rotation of the bracket  212  about the base  208 . A seat-mounting platform  228  is provided. The platform  228  is rotatably mounted to the second end  216  of the bracket  212 . Means  232  are provided for controlling the rotation of the platform  228  about the bracket  212 . A lower seat portion  236  is fixedly attached to the seat-mounting platform  228 . A seat back portion  240  is pivotally mounted to the lower seat portion  236 . Means  244  are provided for adjusting the inclination of the seat back portion  240  with respect to the lower seat portion  236 . 
     In use, the means  224  for controlling the rotation of the bracket  212  about the base  208  is loosened so that the bracket  212  may pivot about the base  208 . The means  232  for controlling the rotation of the platform  228  about the bracket  212  is loosened to permit the seat portions  236 ,  240  to pivot about second end  220  of the bracket  212 . The seat portions  236 ,  240  may now extend outwardly toward the chamber door opening  34  with the seat portions  236 ,  240  facing the door opening  34  to assist a patient to be placed upon the seat. The seat portions  236 ,  240  may now be pivoted upon the seat-mounting platform  228  to allow a patient  248  to face into the chamber  14 . The seat support bracket  212  may now be pivoted upon the base  208  to center the patient  248  within the chamber  14 , the seat portions  236 ,  240  and support bracket  212  may be then secured in place. 
     In yet another variant of the invention, as illustrated in FIGS. 9,  10  and  11 , the means  90  for locking and unlocking the chamber door  54   b  includes at least one means  252  for pivotally mounting the retaining bar  118 . The retaining bar  118  is so mounted to provide clearance for the ring of malleable sealing material  42   b , the first carrier  198  and the first door guide  166  when moving the chamber door  54   b  from the second, open position to the first, closed position. 
     In yet a further variant of the invention, as illustrated in FIG. 5, at least one means  256  for engaging the wedge-shaped portion  106  of the locking shaft  94  so as to retain the door  54  in the second position, is provided. In still a further variant, as illustrated in FIG. 4, a doorstop  260  formed of resilient material is provided. The doorstop  260  serves to limit the motion of the door  54  when moving from the second position to the first, closed position. 
     In still another variant, as illustrated in FIGS. 4 and 6, the means for positioning the door  54  within the chamber  14  in a first position such that the outer surface  62  of the door  54  abuts the sealing material  42  and in a second position permitting entry into the chamber  14  further includes a means  264  for pivotally mounting the second end  190  of the first upper carrier rail  174  to the ceiling  22  of the chamber  14 . Means  268  for adjusting the height of the first  174  and second  178  upper carrier rails above the chamber floor  18  are provided. A means  272  for providing sliding support for the first end  182  of the first upper carrier rail  174  is provided. The means  272  permits the first carrier rail  174  to move toward and away from the chamber door opening  34 . 
     As illustrated in FIG. 5, a first relief notch  276  is provided. The relief notch  276  is located at the first end  150  of the first section  142  of the L-shaped lower floor track  138  and extends at a right angle to the first section  142  toward the chamber door opening  34 . A second relief notch  280  is provided. This relief notch  280  is located at the second end  158  of the first section  142  of the L-shaped lower floor track  138  and extends from the first end  154  of the second section  146  of the L-shaped track  138  at a right angle to the first section  142  toward the chamber door opening  34  in line with the second track section  146 . 
     When the door  54  is positioned in the first, closed position and the locking shaft  94  is moved to the second, extended position, thereby causing the wedge-shaped portion  106  to engage the retaining bar  118 , the door  54  may move toward the door opening  34  to seal against the opening  34 . 
     In still a further variant, as illustrated in FIGS. 3 a  and  3   b , the means for positioning the door  54   b  within the chamber  14   b  in a first position such that the sealing material  42   b  abuts the inner surface  26   b  of the chamber  14   b  and in a second position permitting entry into the chamber  14   b , as illustrated in FIG. 4, further includes a means  264  for pivotally mounting the second end  190  of the first upper carrier rail  174  to the ceiling  22  of the chamber  14 . Means  268  for adjusting the height of the first  174  and second  178  upper carrier rails above the chamber floor  18  are provided. A means  272 , as illustrated in FIGS. 4 and 8, for providing sliding support for the first end  182  of the first upper carrier rail  174  is provided. The means  272  permits the first carrier rail  174  to move toward and away from the chamber door opening  34 . 
     As illustrated in FIG. 5, a first relief notch  276  is provided. The relief notch  276  is located at the first end  150  of the first section  142  of the L-shaped lower floor track  138  and extends at a right angle to the first section toward the chamber door opening  34 . A second relief notch  280  is provided. This relief notch  280  is located at the second end  158  of the first section  142  of the L-shaped lower floor track  138  and extends from the first end  154  of the second section  146  of the L-shaped track  138  at a right angle to the first section  142  toward the chamber door opening  34  in line with the second track section  146 . 
     When the door  54  is positioned in the first, closed position and the locking shaft  94  is moved to the second, extended position, thereby causing the wedge-shaped portion  106  to engage the retaining bar  118 , the door  54  may move toward the door opening  34  to seal against the opening  34 . 
     In a final variant of the invention, as illustrated in FIGS. 12 and 13, the seat pivoting system  204  in combination with a hyperbaric chamber  14  further includes a control member  284 . The control member  284  has a first end  288  and a second end  292  and is rotatably mounted at its first end  288  adjacent the first end  216  of the seat support bracket  212 . The control member  284  is rotatably mounted at its second end  292  adjacent the seat mounting platform  228 . When the seat support bracket  212  is rotated about the base  208  the seat-mounting platform  228  will rotate so as to maintain the orientation of the lower seat portion  236  and seat back portion  240  to the chamber door opening  34 . 
     The door system  10  and seat pivoting system  204  in combination with a hyperbaric chamber have been described with reference to particular embodiments. Other modifications and enhancements can be made without departing from the spirit and scope of the claims that follow.