Thrust-centering crane and method

A thrust-centering pedestal-mounted crane, comprising:

• support means including a vertical kingpost;
• a center pin extending upwardly from said kingpost, said center pin having a lesser circumference than the kingpost circumference;
• upper works revolvable around said kingpost;
• boom means supported by said upper works;
• said upper works including gantry means, said gantry means including gantry vertical members;
• a cross-structure member fixedly attached to said gantry vertical members;
• a bearing retainer comprising a hollow, cylindrical member having an inner retainer surface attached to said cross-structure member;
• a thrust bearing supported on said kingpost;
• a bearing carrier comprising a hollow, cylindrical member having an outer carrier surface, said bearing carrier intermediate said center pin and said bearing retainer;
• said bearing carrier supported on said thrust bearing;
• a radial bearing intermediate said bearing carrier and said center pin;
• said bearing carrier concentrically arranged within said bearing retainer;
• first alignment means including at least one upwardly-extending convex arcuate plate attached to said bearing carrier;
• second alignment means including at least one concave arcuate plate attached to said bearing retainer;
• said second alignment means supported on said first alignment means;
• said at least one convex arcuate plate received within said at least one concave plate;
• said at least one convex arcuate plate having a lesser degree of curvature than the said at least one concave plate;
• the interface of said second alignment means and said first alignment means limited to a predetermined area near the horizontal center of said kingpost;
• and
• said bearing retainer, cross-structure means, gantry means and upper works revolvably supported on said kingpost by said second alignment means.

A thrust-centering pedestal-mounted crane, comprising:

• support means including a vertical kingpost;
• a center pin extending upwardly from said kingpost, said center pin having a lesser circumference than the kingpost circumference;
• upper works revolvable around said kingpost;
• boom means supported by said upper works;
• said upper works including gantry means, said gantry means including two horizontally-spaced gantry vertical members, exterior of and generally parallel to said kingpost, said gantry vertical members extending a predetermined distance above said kingpost;
• a cross-structure member fixedly attached to said gantry vertical members;
• a bearing retainer comprising a hollow, cylindrical member having an inner retainer surface, said bearing retainer attached to said cross-structure member;
• a thrust bearing supported on said kingpost;
• a bearing carrier comprising a hollow, cylindrical member having an outer carrier surface, said bearing carrier intermediate said center pin and said bearing retainer;
• said bearing carrier supported on said thrust bearing;
• a radial bearing intermediate said bearing carrier and said center pin;
• said bearing carrier disposed concentrically within said bearing retainer;
• said inner retainer surface engaging said outer carrier surface at least under load condition of the crane;
• the engagement of said inner retainer surface with said outer carrier surface limited to a predetermined vertical range;
• said outer carrier surface including an outer carrier surface extension engaging said inner retainer surface, said outer carrier surface having a lesser vertical length than said inner retainer surface vertical length;
• first alignment means including two upwardly-extending convex arcuate plates attached to said bearing carrier;
• second alignment means including two concave arcuate plates attached to said bearing retainer;
• said second alignment means supported on said first alignment means, each of said two concave plates aligned with a convex arcuate plate;
• each of said two convex arcuate plates received within an aligned concave arcuate plate;
• each of said at two convex arcuate plates having a lesser degree of curvature than each of said two concave plates;
• the interface of said second alignment means and said first alignment means limited to a predetermined area near the horizontal center of said kingpost;
• said bearing retainer, cross-structure means, gantry means and upper works revolvably supported on said kingpost by said second alignment means.