资料来源 : Webster's Revised Unabridged Dictionary (1913)

Valve \Valve\, n. [L. valva the leaf, fold, or valve of a door:
   cf. F. valve.]
   1. A door; especially, one of a pair of folding doors, or one
      of the leaves of such a door.

            Swift through the valves the visionary fair
            Repassed.                             --Pope.

            Heavily closed, . . . the valves of the barn doors.
                                                  --Longfellow.

   2. A lid, plug, or cover, applied to an aperture so that by
      its movement, as by swinging, lifting and falling,
      sliding, turning, or the like, it will open or close the
      aperture to permit or prevent passage, as of a fluid.

   Note: A valve may act automatically so as to be opened by the
         effort of a fluid to pass in one direction, and closed
         by the effort to pass in the other direction, as a
         clack valve; or it may be opened or closed by hand or
         by mechanism, as a screw valve, or a slide valve.

   3. (Anat.) One or more membranous partitions, flaps, or
      folds, which permit the passage of the contents of a
      vessel or cavity in one direction, but stop or retard the
      flow in the opposite direction; as, the ileocolic, mitral,
      and semilunar valves.

   4. (Bot.)
      (a) One of the pieces into which a capsule naturally
          separates when it bursts.
      (b) One of the two similar portions of the shell of a
          diatom.
      (c) A small portion of certain anthers, which opens like a
          trapdoor to allow the pollen to escape, as in the
          barberry.

   5. (Zo["o]l.) One of the pieces or divisions of bivalve or
      multivalve shells.

   {Air valve}, {Ball valve}, {Check valve}, etc. See under
      {Air}. {Ball}, {Check}, etc.

   {Double-beat valve}, a kind of balance valve usually
      consisting of a movable, open-ended, turban-shaped shell
      provided with two faces of nearly equal diameters, one
      above another, which rest upon two corresponding seats
      when the valve is closed.

   {Equilibrium valve}.
      (a) A balance valve. See under {Balance}.
      (b) A valve for permitting air, steam, water, etc., to
          pass into or out of a chamber so as to establish or
          maintain equal pressure within and without.

   {Valve chest} (Mach.), a chamber in which a valve works;
      especially (Steam Engine), the steam chest; -- called in
      England {valve box}, and {valve casing}. See {Steam
      chest}, under {Steam}.

   {Valve face} (Mach.), 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 seat}. (Mach.)
      (a) The fixed surface on which a valve rests or against
          which it presses.
      (b) A part or piece on which such a surface is formed.

   {Valve stem} (Mach.), a rod attached to a valve, for moving
      it.

   {Valve yoke} (Mach.), a strap embracing a slide valve and
      connecting it to the valve stem.



   14. (Paint.)
       (a) The representation or reproduction of the effect of
           the atmospheric medium through which every object in
           nature is viewed. --New Am. Cyc.
       (b) Carriage; attitude; action; movement; as, the head of
           that portrait has a good air. --Fairholt.

   15. (Man.) The artificial motion or carriage of a horse.

   Note: Air is much used adjectively or as the first part of a
         compound term. In most cases it might be written
         indifferently, as a separate limiting word, or as the
         first element of the compound term, with or without the
         hyphen; as, air bladder, air-bladder, or airbladder;
         air cell, air-cell, or aircell; air-pump, or airpump.

   {Air balloon}. See {Balloon}.

   {Air bath}.
       (a) An apparatus for the application of air to the body.
       (b) An arrangement for drying substances in air of any
           desired temperature.

   {Air castle}. See {Castle in the air}, under {Castle}.

   {Air compressor}, a machine for compressing air to be used as
      a motive power.

   {Air crossing}, a passage for air in a mine.

   {Air cushion}, an air-tight cushion which can be inflated;
      also, a device for arresting motion without shock by
      confined air.

   {Air fountain}, a contrivance for producing a jet of water by
      the force of compressed air.

   {Air furnace}, a furnace which depends on a natural draft and
      not on blast.

   {Air line}, a straight line; a bee line. Hence

   {Air-line}, adj.; as, air-line road.

   {Air lock} (Hydr. Engin.), an intermediate chamber between
      the outer air and the compressed-air chamber of a
      pneumatic caisson. --Knight.

   {Air port} (Nav.), a scuttle or porthole in a ship to admit
      air.

   {Air spring}, a spring in which the elasticity of air is
      utilized.

   {Air thermometer}, a form of thermometer in which the
      contraction and expansion of air is made to measure
      changes of temperature.

   {Air threads}, gossamer.

   {Air trap}, a contrivance for shutting off foul air or gas
      from drains, sewers, etc.; a stench trap.

   {Air trunk}, a pipe or shaft for conducting foul or heated
      air from a room.

   {Air valve}, a valve to regulate the admission or egress of
      air; esp. a valve which opens inwardly in a steam boiler
      and allows air to enter.

   {Air way}, a passage for a current of air; as the air way of
      an air pump; an air way in a mine.

   {In the air}.
       (a) Prevalent without traceable origin or authority, as
           rumors.
       (b) Not in a fixed or stable position; unsettled.
       (c) (Mil.) Unsupported and liable to be turned or taken
           in flank; as, the army had its wing in the air.

   {To take air}, to be divulged; to be made public.

   {To take the air}, to go abroad; to walk or ride out.