| 释义 |
shear-legs
[shear n.1]
A device consisting of three poles of wood or iron bolted together at their upper ends and extended below, carrying tackle for raising heavy weights for machinery; cf. shear n.1 4.
1860Engl. & For. Mining Gloss., Newcastle Terms (ed. 2) 62 Shear-legs. 1875J. H. Collins Metal Mining 49 The boring tools are sometimes worked simply by a rope passed over a shearlegs or triangle. 1900Engineering Mag. XIX. 675 At the Chicago yard there is a steel sheer-legs 100 feet high and of 100 tons capacity. |