| US 7,611,022 B2 | ||
| Upper block | ||
| Steven K. Waisanen, Big Bend, Wis. (US) | ||
| Assigned to MHE Technologies, Inc., Wilmington, Del. (US) | ||
| Filed on Oct. 10, 2007, as Appl. No. 11/869,808. | ||
| Application 11/869808 is a division of application No. 10/967382, filed on Oct. 18, 2004, granted, now 7,293,670. | ||
| Claims priority of provisional application 60/607795, filed on Sep. 08, 2004. | ||
| Prior Publication US 2008/0023682 A1, Jan. 31, 2008 | ||
| Int. Cl. B66C 13/06 (2006.01) | ||
| U.S. Cl. 212—272 [212/274] | 20 Claims |
| 1. A crane having a drum, an upper block, and a lower block, the crane comprising:
a support wall;
a first rope having a first rope end;
a second rope having a second rope end;
an equalizer yoke pivotally mounted to the support wall by a pivot pin and having two load pins, each rope end being coupled
to one of the load pins;
wherein each of the load pins includes a load cell which measures forces carried by the coupled one of the first and second
ropes;
wherein the first and second rope ends are substantially parallel to one another in a direction substantially perpendicular
to a line running through the two load pins;
a yoke pin mounted to the yoke and extending through a slot in the support wall;
wherein the yoke pin is spaced apart from the pivot pin so that the yoke pin pivots about the pivot pin and moves along the
slot when the yoke pivots relative to the support wall to equalize loads between the first and second ropes; and
at least one damper extending between the yoke pin and the support wall to dampen motion of the yoke by providing resistance
on the yoke pin when the yoke pivots relative to the support wall due to failure of one the first and second ropes.
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