Abstract:
An arm portal for ingress and egress within an enclosed, controlled environment, such as an incubator, employs asymmetric orifices to obtain superior arm mobility. The hand/arm portals along with the pass box can be manufactured into a one-piece injection molded assembly that is easily attached to the front face of an enclosed anaerobic environment.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to scientific research and medical equipment. More particularly, the present invention relates to chambers which are provided with a controlled interior atmosphere such as an anaerobic incubator. 
     Various designs for anaerobic incubators exist, but all at the very least share these features: an enclosure with means for inducing and maintaining a prescribed environment; hand/arm access portals for manipulation of items within the controlled environment; and a pass box for moving samples in an out of the controlled environment. Prior art has dictated two designs for the shape of hand/arm portals, one design being circular as shown and described in U.S. Pat. No. 6,100,083 and the second design being best described as an elongated circle as shown and described in U.S. Pat. No. 5,861,305. In the &#39;305 patent, the hand/arm portals are vertically elongated as compared to the circular portals, with their tops and bottoms remaining curved but with the sides only displaying a slight curvature. 
     Both the circular and elongated circular designs limit the scientist&#39;s movement within the controlled environment. Often samples are stored in the back of the enclosure or are introduced to the controlled environment via side pass boxes. Should the scientist or technician be small in stature and as such have a smaller reach, obtaining samples in the back of the enclosure is extremely difficult. Both the circular and elongated circular portals do not allow the scientist to get his/her upper arm and shoulder into the enclosure. Additionally, for anaerobic incubators where the pass boxes are located on the side of the incubator, all scientists have mobility issues, because human elbows are not designed to bend away from the body (i.e. backwards). Moving samples to/from side pass boxes or enclosures is extremely awkward. Due to the shape of the hand/arm portals it is extremely difficult to maneuver one&#39;s left arm to reach a sample contained within a pass box on the right-hand side of the enclosure, because the distance is simply too great; while reaching the sample with one&#39;s right-hand is also difficult due to the elbow&#39;s inability to move in backward. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, superior arm mobility within the anaerobic environment is achieved with a novel geometry for the hand/arm portals that arises from the spatial ergonomics of arm movement within the enclosed environment under standard conditions. Additionally, the hand/arm portals along with the pass box can be manufactured into a one-piece injection molded assembly that is easily attached to front face of the enclosed anaerobic environment. The combination of these novel elements allows a superior working environment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of the arm portal and pass box assembly; 
         FIG. 2  is a back perspective view of the arm portal and pass box assembly; 
         FIG. 3  is a top view of the arm portal and pass box assembly; 
         FIG. 4  is a front view of the arm portal and pass box assembly; 
         FIG. 5  is a right side view of the arm portal and pass box assembly; 
         FIG. 6  is a left side view of the arm portal and pass box assembly; 
         FIG. 7  is a back view of the arm portal and pass box assembly; 
         FIG. 8  is a bottom view of the arm portal and pass box assembly; 
         FIG. 9  is a perspective view of the front panel of an incubator hood; 
         FIG. 10  is an exploded view of the arm portal and pass box assembly with the front panel of an incubator hood; 
         FIG. 11  is a perspective view of the arm portal and pass box assembly mechanically affixed to the front panel of an incubator hood; 
         FIG. 12  in a partial enlarged view of the right-hand side of the arm portal and pass box assembly; 
         FIG. 13  is a top view of the front seal plate of the pass box; 
         FIG. 14  is a front perspective view of the front seal plate of the pass box; 
         FIG. 15  is a front view of the front seal plate of the pass box; 
         FIG. 16  is a right side view of the front seal plate of the pass box; it should be noted that the left side view is a mirror image of the right side view; 
         FIG. 17  is a back perspective view of the front seal plate of the pass box; 
         FIG. 18  is a top view of the back seal plate of the pass box; 
         FIG. 19  is a front perspective view of the back seal plate of the pass box 
         FIG. 20  is a back view of the back seal plate of the pass box; 
         FIG. 21  is a right side view of the back seal plate of the pass box; it should be noted that the left side view is a mirror image of the right side view 
         FIG. 22  is a back perspective view of the back seal plate of the pass box. 
     
    
    
     DETAILED DESCRIPTION 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting. 
     Looking at  FIGS. 1 and 2  the arm portal and pass box assembly  10  is comprised of a unitary or monolithic portal body  12 , a pass box front seal plate assembly  14  and a pass box rear seal plate assembly  16 . The portal body  12  has a left portal  20  and a right portal  18  formed therethrough. These portals are defined by a stepped left portal interior wall  24  and a stepped right portal interior wall  22 . Looking at  FIG. 2 , it can be seen that the rear or inner section of these interior walls  24  and  22  are stepped into a larger diameter that follows the same axial profile as the front or outer inner wall&#39;s axial profile. This step serves to establish a left plug seal face  29  and a right plug seal face  31  that acts as a raised flange for the elastomeric seal of a plug plate that may optionally be inserted from the inside of the chamber. 
     Turning now to  FIGS. 3-6 , each portal,  20  and  18 , is made up of two conjoined rings. The left portal  20  is made of a left single walled outer ring  26  and an enclosed left double walled inner ring  28 . The right portal  18  is made of a right single walled outer ring  25  and an enclosed right double walled inner ring  27 . The exterior side of the left outer ring  26  has a slight outward rear bevel away from its midpoint and has left front flange  32  formed about its front edge. The exterior side of the right outer ring  25  has a slight outward rear bevel away from its midpoint and has left front flange  30  formed about its front edge. 
     These single walled outer rings  25  and  26  have a uniform depth The side walls of the inner rings  28  and  27  do not have a uniform depth but rather are angled such that the depth of the inner rings  28  and  27  increases from the bottom of the ring to the top of the ring. Only the back edge of the inner rings  28  and  27  has a taper. In this manner the front transparent panel of the incubator hood may be angled away from the user&#39;s head to accommodate increased visibility. The inner rings  28  and  27  and the outer rings  26  and  25  have the identical geometric profiles in axial cross section but the outer rings  26  and  25  have a smaller diameter. The two rings transition together at the non-tapered front edge of the inner ring and the smaller diameter rear edge of the outer ring. This is where the left plug seal face  29  and right plug seal face  31  are formed. The space created on the exterior surface of the outer rings  26  and  25  between their front flanges and the transition interface to the inner rings  28  and  27  forms a left glove recess  41 , see  FIG. 8 , and a right glove recess  43  about the periphery of the outer rings  26  and  25 . This allows the retention of an elastic glove assemblies and sealing belt. 
     The axial cross sectional profile of all sections of the portals have a complex geometric configuration made up of several sections of different diameter circles. Each portal,  20  and  18 , has no axis of symmetry. This is best illustrated in  FIG. 12  and explained in the accompanying table. The right portal  18  configuration only will be discussed. The left portal  20  is a mirror image of the right portal  18 . Looking at  FIG. 12 , it can see that the arc segments of right portal  18  have been numbered 1-8, beginning approximately at the two o&#39;clock position, and progressing clockwise around right portal  18  and are described in terms of their arc length in degrees and their root circle&#39;s radius in arbitrary units. 
     
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Right Portal Configuration 
               
             
          
           
               
                   
                   
                 Root Circle Radius 
               
               
                 Arc Segment 
                 Arc Length (degrees*) 
                 (arbitrary units) 
               
               
                   
               
             
          
           
               
                 1 
                 20 
                 8.889 
               
               
                 2 
                 20 
                 7.888 
               
               
                 3 
                 68 
                 2.638 
               
               
                 4 
                 12 
                 14.889 
               
               
                 5 
                 78 
                 2.638 
               
               
                 6 
                 27 
                 8.889 
               
               
                 7 
                 27 
                 7.888 
               
               
                 8 
                 108 
                 2.988 
               
               
                   
               
               
                 *The number of degrees of each arc segment is measured from the center of the root circle for that specific arc segment not from the centroid of the portal configuration. 
               
             
          
         
       
     
     As can be seen the portals are mirror images of each other taken about a vertical line passing through the midpoint of the portal body  12 . Equidistant between the two portals is a pass box section  48 , which is illustrated in  FIGS. 7-8 . All of these elements are held in their spaced configurations by the connection flange portion  38  of the portal body  12 . The flanged portion  38  extends from the rear exterior back edge  40  of the double walled inner rings  28  and  27  and spans the area around the pass box section  48 . This makes a generally planar surface for the placement of a sealing gasket between the portal body  12  and the transparent front panel  44  of the incubator hood. Around the entire flanged portion is formed an O ring groove  42  for the retention of a second sealing mechanism (preferably a compressible O-ring.) 
     The pass box section  48  is a generally rectangular double walled cylinder open on either end. A pass box front seal plate assembly  14  and a pass box rear seal plate assembly  16  are used to seal this chamber from both the outside ambient air and the anaerobic environment within the hood. The front seal plate  14  has an front elastomeric seal groove  50  formed about its inside perimeter and a front transparent panel  52  mechanically affixed about a viewing orifice formed there through ( FIGS. 13-17 ). The rear seal plate  16  has an rear elastomeric seal groove  51  formed about its inside perimeter and a transparent panel  53  mechanically affixed about a viewing orifice formed there through. There is a first and second lock mechanism orifice  54  and  56  formed through the pass box front seal plate assembly  14  and a pass box rear seal plate assembly  16 . 
     To vent out purge gas, when it is introduced into the pass box  48 , there resides a small group of venting orifices  60  on the front seal plate  14  in order to remove any oxygen from the pass box  48  prior to opening the back seal plate assembly  16  to transfer working material into the incubator hood. 
       FIGS. 7 and 8  illustrate the mechanical connection orifices  46  formed through the flanged portion  38  between the exterior edge  40  of the outer wall of the double walled inner rings  22  and  24  and the O ring groove  42  for the attachment of the portal body  12  to the chamber. 
     The benefits and obvious advantages of the improved arm portal and pass box flange  10  are best explained in a description of the operation. Three openings are cut through a planar front transparent panel  44  ( FIG. 11 ) to the approximate dimensions of the interior face of inner rings  27  and  28  as well as the inner cylinder walls of the pass box section  48  as illustrated in  FIG. 9 . A series of holes are drilled in the panel  44  that align with the mechanical connection orifices  46  of the improved arm portal and pass box assembly  10 . A sealing gasket or material may optionally be placed between the flanged portion  38  of the portal body  12  and the panel  44  and an O-ring is placed in the O-ring groove  42  between the flanged portion  38  of the portal body  12  and the panel  44 . Mechanical fasteners such a nuts and bolds are used to connect the panel  44  and the body  12 , see  FIGS. 10-11 . The pass box front seal plate assembly  14  and pass box rear seal plate assembly  16  each have a elastomeric seal inserted into their groove  50  and  51  which are compressed to make a seal with the open ends of the pass box section  48 . The front and rear pass box seal plates  14 ,  16  are attached to portal body  12  via hinge assemblies (not illustrated), that are connected to portal body  12  via hinge mounting holes  62  illustrated in  FIGS. 4 and 8 . 
     The shape of both the left and right arm portals were designed to have a almost flat bottom so that the user could comfortably rest his or her arms on the bottom of the arm portals. The lead in edge, or lip, of each arm portal has a large smooth radii so that the user can comfortably rest his or her arms. The arm portals will accommodate 10″ diameter sleeves and are taller than they are wide in order to accommodate a user of smaller stature; enabling him or her to reach high shelves located at the back of the controlled environment/work space. 
     Additionally, the shape of the arm portals are angled outwards so that all users can easily reach the left and right walls of the controlled environment/work space, and are located as close to the pass box as possible so that the user can put his or her hands together and work directly in front of him/her on the work surface. This specific configuration of the arm portal and pass box assembly maximize the work space, creating the most efficient work area possible. 
     The pass box is sized for holding a stack of five large petri dishes, and contains windows in each door (front and back) for visibility. The height of the bass box is minimized to maximize visibility of the most efficient work area. 
     The above description will enable any person skilled in the art to make and use this invention. It also sets forth the best modes for carrying out this invention. There are numerous variations and modifications thereof that will also remain readily apparent to others skilled in the art, now that the general principles of the present invention have been disclosed. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. 
     It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.