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, a curve of double curvature, or a twisted curve. See Plane curve, under Curve. -- Skew gearing, or Skew bevel gearing (Mach.), toothed gearing, generally resembling bevel gearing, for connecting two shafts that are neither parallel nor intersecting, and in which the teeth slant across the faces of the gears. -- Ske…

which the exhaust steam passes. It is situated in the steam chest, and moved by the valve gear. It is sometimes called a D valve, -- a name which is also applied to a semicylindrical pipe used as a sliding valve. In the illustration, a is the cylinder of a steam engine, in which plays the piston p; b the steam chest, r…

pieces; as, a casting forming the hub and spokes to which the rim of a fly wheel or large gear is bolted; the body of a piston head; a frame for strengthening a core or mold for a casting, etc. Spider ant. (Zoöl.) Same as Solitary ant, under Solitary. -- Spider crab (Zoöl.), any one of numerous species of maioid crabs…

Of or pertaining to a spiral; like a spiral. Spiral gear, or Spiral wheel (Mach.), a gear resembling in general a spur gear, but having its teeth cut at an angle with its axis, or so that they form small portions of screws or spirals. -- Spiral gearing, a kind of gearing sometimes used in light machinery, in which spi…

perdix, allied to the jungle fowl. The males have two or more spurs on each leg. -- Spur gear (Mach.), a cogwheel having teeth which project radially and stand parallel to the axis; a spur wheel. -- Spur gearing, gearing in which spur gears are used. See under Gearing. -- Spur pepper. (Bot.) See the Note under Capsi…

g a series of offsets or parts resembling the steps of stairs; as, a stepped key. Stepped gear, a cogwheel of which the teeth cross the face in a series of steps.

Any instruments of action; an apparatus by which an object is moved or operated; gear; as, fishing tackle, hunting tackle; formerly, specifically, weapons. "She to her tackle fell." Hudibras.

A hydraulic device by which the movement of the wheel on the bridge operates the steering gear at the stern.

Dress; gear; ornaments. Seeing him just pass the window in his woodland trim. Sir W. Scott.

Designating, or pert. to, a gear for reducing or increasing a velocity ratio two to one.

To strip of harness; to loose from harness or gear; as, to unharness horses or oxen. Cowper.

that part of the surface of a valve which comes in contact with the valve seat. -- Valve gear, or Valve motion (Steam Engine), the system of parts by which motion is given to the valve or valves for the distribution of steam in the cylinder. For an illustration of one form of valve gear, see Link motion. -- Valve sea…

gle] soaring through his wide empire of the air To weather his broad sails. Spenser. This gear lacks weathering. Latimer.

, Spinning wheel, etc. See under Bevel, Brake, etc. -- Core wheel. (Mach.) (a) A mortise gear. (b) A wheel having a rim perforated to receive wooden cogs; the skeleton of a mortise gear. -- Measuring wheel, an odometer, or perambulator. -- Wheel and axle (Mech.), one of the elementary machines or mechanical powers,…