Variable opening seal

A method for tranferring material between a first environment and a second environment in preselected quantities, said method comprising the steps of:

• (a) providing a variable opening seal, said seal comprising:
• a housing, a rigid substantially tubular member, first and second resilient tubular elastomeric elements, and activation means for varying the configuration of said seal;
• said housing having an external surface, a first longitudinal axis, an internal cavity centered on said longitudinal axis, a first end defining a first axial opening connecting said external surface to said internal cavity, a second end defining a second axial opening connecting said external surface to said internal cavity, said second axial opening being disposed in opposing relation to said first axial opening, and a radial opening connecting said internal cavity to said external surface between said first axial opening and said second axial opening;
• said rigid substantially tubular member having a second longitudinal axis, a first end defining a third axial opening and a second end defining a fourth axial opening, with a first longitudinal passageway extending therebetween, said rigid substantially tubular member being co-axially located within said housing cavity between said first end of said housing and said second end of said housing such that (i) said third axial opening is disposed in opposing relation to said first axial opening and said fourth axial opening is disposed in opposing relation to said second axial opening, and (ii) said rigid substantially tubular member is restrained from axial movement within said cavity but is free to rotate about said co-incident first and second longitudinal axes;
• said first resilient tubular elastomeric element having a third longitudinal axis, a first end defining a fifth axial opening and a second end defining a sixth axial opening, with a second longitudinal passageway extending therebetween;
• said second resilient tubular elastomeric element having a fourth longitudinal axis, a first end defining a seventh axial opening and a second end defining an eighth axial opening, with a third longitudinal passageway extending therebetween;
• said first elastomeric tubular element being affixed to said housing and to said rigid substantially tubular member so that said fifth axial opening communicates with said first axial opening and said sixth axial opening communicates with said third axial opening;
• and
• said second tubular elastomeric element being affixed to said housing and to said rigid substantially tubular member so that said seventh axial opening communicates with said fourth axial opening and said eighth axial opening communicates with said second axial opening;
• said first and second resilient tubular elastomeric elements and said rigid substantially tubular member being positioned relative to one another such that when said seal is in a first position, said first and second resilient tubular elastomeric elements are twisted upon themselves in opposite directions so as to form a pair of spaced barriers between said first and second axial openings in said housing;
• and
• said activation means being attached to said rigid substantially tubular member and extending through said radial opening in said housing for rotating said rigid substantially tubular member within said housing cavity, said activation means being biased so as to urge said seal toward said first position and being rotatable relative to said housing so as to move said rigid substantially tubular member between (a) a second position wherein said second longitudinal passageway through said first resilient tubular elastomeric element is open and said second resilient tubular elastomeric element is further twisted and closed upon itself, and (b) a third position wherein said third longitudinal passageway through said second resilient tubular elastomeric element is open and said first resilient tubular elastomeric element is further twisted and closed upon itself;
• (b) sequentially manipulating said activation means in order so as to:
• (1) place said seal in said second position and allow material from said first environment to enter said rigid substantially tubular member and the portions of said first and second resilient tubular elastomeric elements immediately adjacent thereto;
• (2) place said seal in said first position thereby separating a preselected quantity of said material from said first environment from the remainder of said material;
• and
• (3) place said seal in said third position thereby allowing said preselected quantity of said material from said first environment to move toward said second environment.