| 释义 |
ˈcross-ˌhead, n.
[cross- 4.]
1. a. The bar at the end of the piston-rod of a steam-engine, which slides between straight guides, and communicates the motion to the connecting-rod, etc.
1827Mech. Mag. VIII. 2 Can the cross-head, side rods, cranks, shaft..be reduced? 1861T. L. Peacock Gryll. Gr. xx. 179 Vibrating..with one invariable regulated motion like the cross-head of a side-lever steam engine.
attrib.1850Weale Dict. Terms, Cross-head guides, in locomotive engines, the parallel bars between which the cross-head moves. Cross-head blocks..the parts which slide between the parallel guides.
b. Any beam across the top of a piece of mechanism.
1844H. Stephens Bk. Farm I. 417 The draught shackle..is held in its place upon the cross-head..by the draught⁓bolt. Ibid. II. 134 The handle..terminates in a crosshead. a1884Knight Dict. Mech. Suppl., Cross Head, a cruciform-shaped four-handled bar, at the upper end of a drill-rod or earth-auger. 1884Science III. 314 Two side-screws, carrying the top crosshead. 1888Encycl. Brit. XXIII. 151/1 Thus avoiding torsion of the polar axis at the expense of greatly increased length of the cross-head. 1901Merwin & Webster Calumet ‘K’ xvi. 322 Another endless series of cups was carrying the wheat aloft. It went over the cross-head and down a spout.
2. A heading to a paragraph printed across the page or column in the body of an article.
1888Pall Mall G. 1 Sept. 11/2 In two cases Mr. Knowles allows frequent ‘cross-heads’. 1964Friend 4 Sept. 1067/2 The memorandum continues (and from this point, inserting only crossheads, we quote it in full): We cannot [etc.].
3. Mining. A heading running across a vein.
1877R. W. Raymond Statist. Mines & Mining 197 At the point of connection the eastern limit of the south vein is defined by a cross-head.., and to the east of this cross-head no trace of the fissure has as yet been found.
4. cross-head brasses pl., the brass bearings of the cross-head of a steam or other engine; cross-head pin, the pin by which the connecting-rod is attached to the piston-rod.
1865Daily News 26 July 3/1 No. 80 torpedo boat..broke down owing to a defect in the crosshead brasses. 1887D. A. Low Machine Drawing xii. 51 The cross-head pin need not be drawn separately. 1889Hasluck Model Engin. Handybk. viii. 91 The hole in cross-head must be broached out till the cross-head pin will nearly fit it.
Hence ˈcross-head v., to furnish with a cross-head (sense 2).
1890Pall Mall G. Jan., The Tablet..cross-heads one of its paragraphs ‘The Need of the Confessional’. 1908‘Ian Hay’ Right Stuff iii. 42, I doubt now if I could write out twenty lines of ‘Paradise Lost’ without cross-heading them. |