What is "universal joint"

Joint \Joint\ (joint), n. [F. joint, fr. joindre, p. p. joint. See Join.]

1. The place or part where two things or parts are joined or united; the union of two or more smooth or even surfaces admitting of a close-fitting or junction; junction; as, a joint between two pieces of timber; a joint in a pipe.

2. A joining of two things or parts so as to admit of motion; an articulation, whether movable or not; a hinge; as, the knee joint; a node or joint of a stem; a ball and socket joint. See Articulation.

   A scaly gauntlet now, with joints of steel, Must glove this hand.
   --Shak.

   To tear thee joint by joint.
   --Milton.

3. The part or space included between two joints, knots, nodes, or articulations; as, a joint of cane or of a grass stem; a joint of the leg.

4. Any one of the large pieces of meat, as cut into portions by the butcher for roasting.

5. (Geol.) A plane of fracture, or divisional plane, of a rock transverse to the stratification.

6. (Arch.) The space between the adjacent surfaces of two bodies joined and held together, as by means of cement, mortar, etc.; as, a thin joint.

7. The means whereby the meeting surfaces of pieces in a structure are secured together.

8. [ Jag a notch.] A projecting or retreating part in something; any irregularity of line or surface, as in a wall. [Now Chiefly U. S.]

9. (Theaters) A narrow piece of scenery used to join together two flats or wings of an interior setting.

10. a disreputable establishment, or a place of low resort, as for smoking opium; -- also used for a commercial establishment, implying a less than impeccable reputation, but often in jest; as, talking about a high-class joint is an oxymoron. [Slang]

11. a marijuana cigarette. [Slang]

12. prison; -- used with ``the''. [Slang] `` he spent five years in the joint.'' Coursing joint (Masonry), the mortar joint between two courses of bricks or stones. Fish joint, Miter joint, Universal joint, etc. See under Fish, Miter, etc. Joint bolt, a bolt for fastening two pieces, as of wood, one endwise to the other, having a nut embedded in one of the pieces. Joint chair (Railroad), the chair that supports the ends of abutting rails. Joint coupling, a universal joint for coupling shafting. See under Universal. Joint hinge, a hinge having long leaves; a strap hinge. Joint splice, a re["e]nforce at a joint, to sustain the parts in their true relation. Joint stool.

    1. A stool consisting of jointed parts; a folding stool.
       --Shak.

    2. A block for supporting the end of a piece at a joint; a joint chair.

       Out of joint, out of place; dislocated, as when the head of a bone slips from its socket; hence, not working well together; disordered. ``The time is out of joint.''
       --Shak.

Universal \U`ni*ver"sal\, a. [L. universalis: cf. F. universel, OF. also universal. See Universe.]

1. Of or pertaining to the universe; extending to, including, or affecting, the whole number, quantity, or space; unlimited; general; all-reaching; all-pervading; as, universal ruin; universal good; universal benevolence or benefice. ``Anointed universal King.''
   --Milton.

   The universal cause Acts not by partial, but by general laws.
   --Pope.

   This universal frame began.
   --Dryden.

   Note: Universal and its derivatives are used in common discourse for general and its derivatives. See General.

2. Constituting or considered as a whole; total; entire; whole; as, the universal world.
   --Shak.

   At which the universal host up dent A shout that tore Hell's concave.
   --Milton.

3. (Mech.) Adapted or adaptable to all or to various uses, shapes, sizes, etc.; as, a universal milling machine.

4. (Logic) Forming the whole of a genus; relatively unlimited in extension; affirmed or denied of the whole of a subject; as, a universal proposition; -- opposed to particular; e. g. (universal affirmative) All men are animals; (universal negative) No men are omniscient.

   Universal chuck (Mach.), a chuck, as for a lathe, having jaws which can be moved simultaneously so as to grasp objects of various sizes.

   Universal church, the whole church of God in the world; the catholic church. See the Note under Catholic, a., 1.

   Universal coupling. (Mach.) Same as Universal joint, below.

   Universal dial, a dial by which the hour may be found in any part of the world, or under any elevation of the pole.

   Universal instrument (Astron.), a species of altitude and azimuth instrument, the peculiarity of which is, that the object end of the telescope is placed at right angles to the eye end, with a prism of total reflection at the angle, and the eye end constitutes a portion of the horizontal axis of the instrument, having the eyepiece at the pivot and in the center of the altitude circle, so that the eye has convenient access to both at the same time.

   Universal joint (Mach.), a contrivance used for joining two shafts or parts of a machine endwise, so that the one may give rotary motion to the other when forming an angle with it, or may move freely in all directions with respect to the other, as by means of a cross connecting the forked ends of the two shafts (Fig. 1). Since this joint can not act when the angle of the shafts is less than 140[deg], a double joint of the same kind is sometimes used for giving rotary motion at angles less than 140[deg] (Fig. 2).

   Universal umbel (Bot.), a primary or general umbel; the first or largest set of rays in a compound umbel; -- opposed to partial umbel. A universal involucre is not unfrequently placed at the foot of a universal umbel.

   Syn: General; all; whole; total. See General.

n. A coupling that allows different parts of a machine not in line with each other some freedom of movement at the same time as transmitting rotary motion.

n. coupling that connects two rotating shafts allowing freedom of movement in all directions; "in motor vehicles a universal joint allows the driveshaft to move up and down as the vehicle passes over bumps" [syn: universal]

A universal joint, (universal coupling, U-joint, Cardan joint, Spicer or Hardy Spicer joint, or Hooke's joint) is a joint or coupling in a rigid rod that allows the rod to 'bend' in any direction, and is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, connected by a cross shaft. The universal joint is not a constant-velocity joint.