发明名称 |
Portable and collapsible derrick structure |
摘要 |
A pickup truck derrick assembly includes a base frame, a derrick A-frame pivotally mounted on the base frame, a derrick frame erection subassembly, a frame support and locking subassembly and a cable compensation system. The frame erection subassembly includes an elongated track. A roller or carriage subassembly rides on the track and engages the A-frame. Movement of the carriage along the track raises and lowers the A-frame. The A-frame is held in an erected position by support braces pivotally connected at one end to the base frame. Each brace slidably engages a sleeve mounted on the A-frame. A locking mechanism automatically secures the braces to the sleeves when the A-frame is erected. A pulley and cable arrangement including a compensation pulley on a support arm fixed to the A-frame compensates for hoist cable slackening when the A-frame is pivoted to its storage position.
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申请公布号 |
US4615450(A) |
申请公布日期 |
1986.10.07 |
申请号 |
US19840621154 |
申请日期 |
1984.06.15 |
申请人 |
KENNARD, JR., DWIGHT C.;KENNARD, JAMES C. |
发明人 |
KENNARD, JR., DWIGHT C.;KENNARD, JAMES C. |
分类号 |
B66C23/36;(IPC1-7):B66C23/42 |
主分类号 |
B66C23/36 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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