James C Abraham

US Patent:

RE295396, Feb 14, 1978

Filed:

Dec 6, 1976

Appl. No.:

5/747802

Inventors:

Herbert L. Willke - Houston TX
James G. Abraham - Palos Verdes Peninsula CA

Assignee:

Armco Steel Corporation - Middletown OH

International Classification:

B66F 712

US Classification:

254 89R

Abstract:

In offshore platforms and the like of the type comprising a structure, such as a hull, and a plurality of upright legs for supporting the structure on the floor of a body of water, the invention provides an improved rack-and-pinion type jacking apparatus for connecting the structure to the legs in vertically adjustable fashion. For each leg, at least one dual rack bar is employed, the rack bar having two opposed sets of rack teeth each extending along a different one of the two edges of the bar. A jacking unit is mounted on the structure adjacent each rack bar and includes at least one pair of drive pinions with the pinions of the pair each meshed with a different one of the two sets of rack teeth, so that the two pinions are opposed across the rack bar. When the legs each comprise a number of tubular column members, one of the dual rack bars is provided for each of a plurality of the column members of each leg. Alternatively, when the legs are made up of a single tubular member, one or more of the dual rack bars are secured to the single tubular member of each leg.