What is "air spring"

Spring \Spring\, n. [AS. spring a fountain, a leap. See Spring, v. i.]

1. A leap; a bound; a jump.

   The prisoner, with a spring, from prison broke.
   --Dryden.

2. A flying back; the resilience of a body recovering its former state by its elasticity; as, the spring of a bow.

3. Elastic power or force.

   Heavens! what a spring was in his arm!
   --Dryden.

4. An elastic body of any kind, as steel, India rubber, tough wood, or compressed air, used for various mechanical purposes, as receiving and imparting power, diminishing concussion, regulating motion, measuring weight or other force.

   Note: The principal varieties of springs used in mechanisms are the spiral spring (Fig. a), the coil spring (Fig. b), the elliptic spring (Fig. c), the half-elliptic spring (Fig. d), the volute spring, the India-rubber spring, the atmospheric spring, etc.

5. Any source of supply; especially, the source from which a stream proceeds; an issue of water from the earth; a natural fountain. ``All my springs are in thee.''
   --Ps. lxxxvii. 7. ``A secret spring of spiritual joy.''
   --Bentley. ``The sacred spring whence right and honor streams.''
   --Sir J. Davies.

6. Any active power; that by which action, or motion, is produced or propagated; cause; origin; motive.

   Our author shuns by vulgar springs to move The hero's glory, or the virgin's love.
   --Pope.

7. That which springs, or is originated, from a source; as:

   1. A race; lineage. [Obs.]
      --Chapman.

   2. A youth; a springal. [Obs.]
      --Spenser.

   3. A shoot; a plant; a young tree; also, a grove of trees; woodland. [Obs.]
      --Spenser. Milton.

8. That which causes one to spring; specifically, a lively tune. [Obs.]
   --Beau. & Fl.

9. The season of the year when plants begin to vegetate and grow; the vernal season, usually comprehending the months of March, April, and May, in the middle latitudes north of the equator. ``The green lap of the new-come spring.''
   --Shak.

   Note: Spring of the astronomical year begins with the vernal equinox, about March 21st, and ends with the summer solstice, about June 21st.

10. The time of growth and progress; early portion; first stage; as, the spring of life. ``The spring of the day.''
    --1 Sam. ix. 26.

    O how this spring of love resembleth The uncertain glory of an April day.
    --Shak.

11. (Naut.)

    1. A crack or fissure in a mast or yard, running obliquely or transversely.

    2. A line led from a vessel's quarter to her cable so that by tightening or slacking it she can be made to lie in any desired position; a line led diagonally from the bow or stern of a vessel to some point upon the wharf to which she is moored. Air spring, Boiling spring, etc. See under Air, Boiling, etc. Spring back (Bookbinding), a back with a curved piece of thin sheet iron or of stiff pasteboard fastened to the inside, the effect of which is to make the leaves of a book thus bound (as a ledger or other account or blank book) spring up and lie flat. Spring balance, a contrivance for measuring weight or force by the elasticity of a spiral spring of steel. Spring beam, a beam that supports the side of a paddle box. See Paddle beam, under Paddle, n. Spring beauty.

       1. (Bot.) Any plant of the genus Claytonia, delicate herbs with somewhat fleshy leaves and pretty blossoms, appearing in springtime.

       2. (Zo["o]l.) A small, elegant American butterfly ( Erora l[ae]ta) which appears in spring. The hind wings of the male are brown, bordered with deep blue; those of the female are mostly blue.

          Spring bed, a mattress, under bed, or bed bottom, in which springs, as of metal, are employed to give the required elasticity.

          Spring beetle (Zo["o]l.), a snapping beetle; an elater.

          Spring box, the box or barrel in a watch, or other piece of mechanism, in which the spring is contained.

          Spring fly (Zo["o]l.), a caddice fly; -- so called because it appears in the spring.

          Spring grass (Bot.), vernal grass. See under Vernal.

          Spring gun, a firearm discharged by a spring, when this is trodden upon or is otherwise moved.

          Spring hook (Locomotive Engines), one of the hooks which fix the driving-wheel spring to the frame.

          Spring latch, a latch that fastens with a spring.

          Spring lock, a lock that fastens with a spring.

          Spring mattress, a spring bed.

          Spring of an arch (Arch.) See Springing line of an arch, under Springing.

          Spring of pork, the lower part of a fore quarter, which is divided from the neck, and has the leg and foot without the shoulder. [Obs.]
          --Nares.

          Sir, pray hand the spring of pork to me.
          --Gayton.

          Spring pin (Locomotive Engines), an iron rod fitted between the springs and the axle boxes, to sustain and regulate the pressure on the axles.

          Spring rye, a kind of rye sown in the spring; -- in distinction from winter rye, sown in autumn.

          Spring stay (Naut.), a preventer stay, to assist the regular one.
          --R. H. Dana, Jr.

          Spring tide, the tide which happens at, or soon after, the new and the full moon, and which rises higher than common tides. See Tide.

          Spring wagon, a wagon in which springs are interposed between the body and the axles to form elastic supports.

          Spring wheat, any kind of wheat sown in the spring; -- in distinction from winter wheat, which is sown in autumn.

Air \Air\ ([^a]r), n. [OE. air, eir, F. air, L. a["e]r, fr. Gr. 'ah`r, air, mist, for 'a[digamma]hr, fr. root 'a[digamma] to blow, breathe, probably akin to E. wind. In sense 10 the French has taking a meaning fr. It. aria atmosphere, air, fr. the same Latin word; and in senses 11, 12, 13 the French meaning is either fr. L. aria, or due to confusion with F. aire, in an older sense of origin, descent. Cf. A["e]ry, Debonair, Malaria, Wind.]

1. The fluid which we breathe, and which surrounds the earth; the atmosphere. It is invisible, inodorous, insipid, transparent, compressible, elastic, and ponderable.

   Note: By the ancient philosophers, air was regarded as an element; but modern science has shown that it is essentially a mixture of oxygen and nitrogen, with a small amount of carbon dioxide, the average proportions being, by volume: oxygen, 20.96 per cent.; nitrogen, 79.00 per cent.; carbon dioxide, 0.04 per cent. These proportions are subject to a very slight variability. Air also always contains some vapor of water.

2. Symbolically: Something unsubstantial, light, or volatile. ``Charm ache with air.''
   --Shak.

   He was still all air and fire. [Air and fire being the finer and quicker elements as opposed to earth and water.]
   --Macaulay .

3. A particular state of the atmosphere, as respects heat, cold, moisture, etc., or as affecting the sensations; as, a smoky air, a damp air, the morning air, etc.

4. Any a["e]riform body; a gas; as, oxygen was formerly called vital air. [Obs.]

5. Air in motion; a light breeze; a gentle wind.

   Let vernal airs through trembling osiers play.
   --Pope.

6. Odoriferous or contaminated air.

7. That which surrounds and influences.

   The keen, the wholesome air of poverty.
   --Wordsworth.

8. Utterance abroad; publicity; vent.

   You gave it air before me.
   --Dryden.

9. Intelligence; information. [Obs.]
   --Bacon.

10. (Mus.)

    1. A musical idea, or motive, rhythmically developed in consecutive single tones, so as to form a symmetrical and balanced whole, which may be sung by a single voice to the stanzas of a hymn or song, or even to plain prose, or played upon an instrument; a melody; a tune; an aria.

    2. In harmonized chorals, psalmody, part songs, etc., the part which bears the tune or melody -- in modern harmony usually the upper part -- is sometimes called the air.

11. The peculiar look, appearance, and bearing of a person; mien; demeanor; as, the air of a youth; a heavy air; a lofty air. ``His very air.''
    --Shak.

12. Peculiar appearance; apparent character; semblance; manner; style. It was communicated with the air of a secret. --Pope. 12. pl. An artificial or affected manner; show of pride or vanity; haughtiness; as, it is said of a person, he puts on airs. --Thackeray. 14. (Paint.)

    1. The representation or reproduction of the effect of the atmospheric medium through which every object in nature is viewed.
       --New Am. Cyc.

    2. 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.

       1. An apparatus for the application of air to the body.

       2. 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.

          1. Prevalent without traceable origin or authority, as rumors.

          2. Not in a fixed or stable position; unsettled.

    3. (Mil.) Unsupported and liable to be turned or taken in flank; as, the army had its wing in the air.

       on the air, currently transmitting; live; -- used of radio and television broadcasts, to indicate that the images and sounds being picked up by cameras and microphones are being broadcast at the present moment.

       Note: In call-in programs where individuals outside a radio or television studio have telephoned into the station, when their voice is being directly broadcast, the host of the program commonly states ``You're on the air.'' as a warning that the conversation is not private.

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

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

n. a mechanical device using confined air to absorb the shock of motion [syn: air cushion]