| 摘要 |
<p>762,416. Boring earth and rock. KINNEAR MOODIE & CO., Ltd., and FOSTER CONSTRUCTIONAL ENGINEERS, Ltd., A. Sept. 16, 1955 [June 18, 1954], No. 17915/54. Class 85. In a Greathead or like shield a head is rotatably mounted and driven so as to leave a central area to the rear of the head for accommodation of conveyor means for removal of the spoil. The head 7 has a rearwardly projecting drum 16 rotatably supported by rollers 19, 20 running on tracks 17, 18 supported in the shield 1. Motors 24 and reduction gearings 23 are supported around the internal periphery of the shield and drive pinions 22 engaging a gear ring 21 on the outside of the drum 16. The head 7 has digging tools 8 and ploughs carried on diametrical arms, the spoil being conveyed by shoots 13 into the interior of the drum 16 where inwardly projecting fins 14a project it into trucks 14 running on rails 15 supported cantilever fashion in the shield, or on to an endless band conveyor. Hydraulic jacks 4 may bear against the last erected tunnel lining section. Rotation of the shield 1 may be prevented by exterior radial fins or forwardly projecting ploughs 2b mounted on the shield 1.</p> |
