[ad. G. spanner (also spänner, Sw. spännare), f. spannen SPAN v.2]
† 1. An instrument by which the spring in a wheel-lock firearm was spanned or wound up. Obs.
Phillips (ed. Kersey, 1706) has ‘Spanner, the Cock of a Carbine or Fusee’; hence in later Dicts., as Bailey (1721), Johnson (1755), with ‘Lock’ in place of ‘Cock.’
1639. R. Ward, Animadv. Warre, I. 293. A case of good Firelocke Pistolles,… with his Spanner and flaske boxes.
1644. Howell, England’s Tears for Pres. Wars, in Dodona’s Grove, 169. My Prince his Court is now full of nothing but Buff-Coats, Spanners, and Musket Rests.
1688. R. Holme, Armoury, III. xx. (Roxb.), 243/2. The second is called a Spanner; it is a thing made of Iron, haueing a square hole in the bending part of it, by which the springs of wheele locks are wound vp.
[1863. W. Thornbury, True as Steel, II. 29. He then took the spanner … and bent the spring which communicated with the axis-pin of his wheel-lock.]
2. A hand-tool, usually consisting of a small bar of steel, having an opening, grip or jaw at the end that fits over or clasps the nut of a screw, a bolt, coupling, etc., and turns it or holds it in position; a wrench.
There are several makes of spanner, and they vary greatly in shape and size, some having one opening, others two; some taking one size of nut, etc., others being adjustable to nuts of different sizes.
1790. W. H. Marshall, Rur. Econ. Midl., II. 443. Spanner; a wrench; a nut screw-driver.
1831. J. Holland, Manuf. Metal, I. 215. A screw attached to a spanner or lever.
1858. Greener, Gunnery, 101. Wood carriage complete, with wrought iron screw and spanner for elevating mortar.
1888. Rutley, Rock-Forming Min., 22. A nut which screws on to the end of the spindle and is tightened up by means of a spanner.
attrib. and Comb. 1830. G. R. Ainslie, Anglo-French Coinage, 66. Two spanner-like towers.
1902. Marshall, Metal Tools, 69. The small worm shown in the spanner head.
3. Mech. a. A bar or lever for opening the valves of a steam-engine (see quots.).
1773. W. Emerson, Mechanics (ed. 3), 230. The horizontal piece h3, called the spanner; so that moving h back and forward, moves the plate 45 over the hole 2, and back again.
1824. ‘R. Stuart,’ Hist. Steam Engine, 175. Two valves, which are moved alternately by levers acted on on the outside from the revolution of a spanner or lever attached to the hollow axle.
1869. Rankine, Machine & Hand-tools, Pl. F 1. 2. Lower down on this spindle … is keyed a duplex spanner or rocking lever 1, one end of which is attached … to the valve rod of the small engine.
b. In a parallel-motion steam-engine (see quots.)
1846. A. Young, Naut. Dict., 306. The lever e is called the Spanner or Lever of Parallel Motion.
1867. Smyth, Sailor’s Word-bk., 640. Spanner.… An important balance in forming the radius of parallel motion in a steam-engine, since it reconciles the curved sweep which the side-levers describe with the perpendicular movement of the piston-rod, by means of which they are driven.
