Patent ID: 8739988
Filing Date: 2014-06-03
Classification: B66C,Y10T

Abstract:
1. A crane having an upper works rotatably mounted on a lower works, the crane including at least one column member, the column member comprising: a) at least a first and a second column segment each with a longitudinal axis and a first and a second end, the second end of the first segment being coupled to the first end of the second segment; b) at least a first, a third and a fifth connector on the second end of the first segment respectively mating with at least a second, a fourth and a sixth connector on the first end of the second segment; c) each of the connectors comprising at least a first extension having a through-hole there through, the through-hole having an axis perpendicular to said longitudinal axis and positioned in the extension such that the through-holes of mating connectors are aligned when the column segments are aligned; d) each of the connectors comprising a compressive load bearing surface, the compressive load bearing surfaces being positioned to carry compressive loads between the first and second column segments when the column segments are aligned; e) a first pin manufactured to fit tightly through the through-hole of the first extension on the first connector and the through-hole of the first extension on the second connector to hold the first and second connectors together; and a second pin manufactured to fit loosely through the through-hole of the first extension on the third connector and the through-hole of the first extension on the fourth connector on the first end of the second segment to hold the second and fourth connectors together; f) wherein the inside diameters of all holes through which the first pin extends are the same as one another, and the inside diameters of all holes through which the second pin extends are the same as one another; and g) wherein the ratio of N to M is at least 2, where: