| 释义 |
sprocket, n.|ˈsprɒkɪt|
Also 6 sprokett, 6, 9 sproket.
[Of obscure origin.]
1. Carpentry and Building. A triangular piece of timber used in framing, esp. one fastened on the foot of a rafter in order to raise the level of the eaves.
1536MS. Acc. St. John's Hosp., Canterb., To Nycoles & Horton for makyng sprokettis & a grunsyll att Arnoldes, ij d. 1593MS. Churchw. Acc. St. Andrew's, Canterb., For setting vp a forme, nayles and sproketes, xiij d. 1703[R. Neve] City & C. Purchaser 121 A Coving-cornish..has a great Casement, or Hollow in it, which is commonly Lathed and Plaister'd upon Compass, Sprockets, or Brackets. 1880J. Leaning Quantity Survey. 61 Sprockets.—State what size two are cut out of.
2. a. A projection (either forked or simple) from the rim of a wheel, engaging with the links of a chain.
1750T. R. Blanckley Naval Expos. 126 Sprockets are made not unlike a large Horse Shoe, drove into the Wheel, and the Chain works on them. 1875Knight Dict. Mech. 522/1 The sprockets on the wheel are adapted to receive the links of the chain successively. Ibid. 2292/2 The sprockets may be forked, and thus made to partially embrace the links of the chain. 1897C.T.C. Monthly Gaz. Jan. 21 A roller-chain passing over ordinary sprockets.
b. attrib. and Comb., as sprocket-wheel; sprocket hole, each of a line of holes along film or paper tape with which sprockets can engage to propel it or keep it correctly aligned.
1910F. H. Richardson Motion Picture Handbk. 101 Old, dry films jump because..the *sprocket holes are shrunken. 1931B. Brown Talking Pictures viii. 182 Bad tracking produces a loud hum due to either the picture or the sprocket holes running across the light beam. 1960M. G. Say et al. Analogue & Digital Computers ix. 263 A row of holes across the tape consists of one sprocket hole, 0·043 in. diameter.., and up to five information holes, 0·072 in. diameter. 1971Southerly XXXI. 138, I could print those four or five with the sprocket holes still on the film. 1980S. Hockey Guide Computer Applic. Humanities ii. 25 It is normally necessary to leave a foot or so of blank tape with only the sprocket holes punched at each end of a paper tape.
1769Falconer Dict. Marine (1780) s.v. Pump, The *sprocket-wheels, employed to wind it up from the ship's bottom. 1792J. Townsend Journ. Spain I. 170 It [the noria] consists of a band or girdle passing over a sprocket wheel. 1846A. Young Naut. Dict. 239 Above the upper extremities of these tubes there is fixed a sproket-wheel worked by crank-handles. c1860H. Stuart Seaman's Catech. 54 It is rove round the sprocket-wheel of the capstan. 1896Westm. Gaz. 21 Nov. 7/2 The chain, instead of acting direct on the driving wheel, passes from the sprocket wheel to another at the back of the saddle.
c. ellipt. A sprocket-wheel, esp. that of a cycle; and (Cinemat.), one that propels film by engaging with perforations along its edge.
1886J. M. Caulfeild Seamanship Notes 3 Parts of the Capstan. Drum head, barrel, sprocket. 1893Fortn. Rev. No. 314. 241 The elliptical sprocket, or lower chain-wheel, has caused much discussion. 1910F. H. Richardson Motion Picture Handbk. 110 The intermittent sprocket..should be watched and promptly renewed when there are signs of serious wear. 1925R. V. Johnson Mod. Picture Theatre Electrical Equipment & Projection 67 The intermittent sprocket pulls the film through the gate, and the bottom sprocket carries the film to the lower spool box. 1953L. J. Wheeler Princ. Cinemat. vi. 181 It is reasonable to expect the sprocket dimensions to be different to those in the camera mechanism. 1977D. MacKenzie Raven & Kamikaze vi. 77 Slade unwound the film from the sprockets and put it back in the can.
attrib.1897Outing XXX. 277/2 A wheel, from handle-bar to sprocket-chain. Ibid. 370/2 A sprocket-lock, which was guaranteed to prevent any sprocket from revolving. Ibid. 371/1, I snapped in its place my sprocket-guard. 1910F. H. Richardson Motion Picture Handbk. 102 A machine with worn intermittent sprocket teeth. 1935Discovery Nov. 325/2 Disturbances such as sprocket-tooth ripple.
3. Naut. One of the teeth of a pawl-rim.
1903Speaker 7 Feb. 452/1 The Hermione capstans are of the dangerous old-fashioned type, fitted with the antiquated pawls and sprockets. 1906Temple Bar Jan. 59 The little iron pawls..begin to click and clatter, as they pass over their sprockets.
Hence ˈsprocketed a., furnished with sprockets or sprocket holes.
1895Queenslander 7 Dec. 1071/1 The chain runs on and engages sprocketed wheels. 1967P. Grosset Compl. Bk. Amateur Film Making viii. 143/2 You will need to use..sprocketed tape (which cannot slip, shrink or stretch). 1978[see next]. |