Apparatus for raising and lowering a heavy weight

Claim 1

Apparatus for raising and lowering a heavy weight comprising a column, a floatable working platform adapted to be moved along said column, an upper outer ring surrounding said column, a lower outer ring surrounding said column and having a spaced distance from said upper outer ring, each of said outer rings having a tapered inner surface, a plurality of upper and lower wedges each of which has a tapered outer surface which may be engaged with the corresponding tapered surface of either of said outer rings, frames for holding said upper and lower wedges, several cylinders for operating said wedges, upper and lower inverted tapered blocks disposed on said upper and lower outer rings respectively, upper and lower inverted tapered wedges which may be engaged with the corresponding tapered surfaces of said inverted tapered blocks, frames for holding said upper and lower inverted wedges, cylinders for operating said upper and lower inverted wedges, guide means for moving said upper and lower inverted wedge holding frames in the direction parallel to the inverted tapered surface, main cylinders coupling said upper and lower outer rings and adapted to move said working platform and column, and tie rods passing through the upper and lower outer rings and connected to the working platform with the top end of said tie rod being projected, each said tie rod having means for preventing the upper outer ring from removing from the tie rod at the top end and having a step portion for receiving the lower outer ring.