Patent ID: 6151840
Filing Date: 2000-11-28
Classification: E04B,E04H,G02B

Abstract:
A combination comprising:(a) a base;(b) a support structure;(c) a first cylindrical section having side walls and upper and lower open ends, the first cylindrical section being vertically movable between a lowermost first cylindrical section position and an uppermost first cylindrical section position;(d) a second cylindrical section having side walls and upper and lower open ends, the second cylindrical section being vertically movable between a lowermost second cylindrical section position and an uppermost second cylindrical section position, the second cylindrical section being disposed in telescope-like relationship with the first cylindrical section;(e) a cover disposed directly above the upper open ends of the first and second cylindrical sections;(f) a driver for moving the first cylindrical section between the lowermost and uppermost first cylindrical section positions and for moving the second cylindrical section between the lowermost and uppermost second cylindrical section positions;wherein, when the first cylindrical section is disposed at the lowermost first cylindrical section position and the second cylindrical section is disposed at the uppermost second cylindrical section position, the base, the first cylindrical section, the second cylindrical section and the cover define an enclosed chamber.