Self-leveling bottom block assembly
US7963579B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 2007 |
| Grant date | Jun 21, 2011 |
| Priority date | — |
| Expiry date | Oct 31, 2029 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66D3/04
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A bottom block assembly includes a block having a central vertical axis, a hook secured to the block for attaching a load to the block, a first pair of sheaves rotatably attached to the block, a first rope reeved about the first pair of sheaves, a second pair of sheaves rotatably attached to the block, and a second rope reeved about the second pair of reeves. The first and second pairs of sheaves are each equally spaced about the central vertical axis. The first pair of sheaves are located higher on the block than the second pair of sheave so that a portion of the first rope located between the first pair of sheaves crosses over a portion of the second rope located between the second pair of sheaves. If either rope fails, the other rope ensures the block remains level with a full load attached to the hook.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.