toggle mechanism

Combination of solid, usually metallic links (bars), connected by pin (hinge) joints arranged so that a small force applied at one point can create a much larger force at another point. Seealso linkage.

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Form of materialism that holds that all natural processes can be explained in terms of laws of matter in motion. Upholders of mechanism were mainly concerned with eliminating from science all occult entities, such as substantial form, that could not be empirically observed or mathematically treated. It thus opposed the use of teleological assumptions as explanatory principles in natural science (see teleology). Seealso atomism.

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Arrangement of mechanical parts used to obtain a reciprocating straight-line motion from a rotating shaft. It serves the same purpose as a slider-crank mechanism and is particularly useful when the required stroke of the reciprocating motion is small in comparison with the dimensions of the driving shaft. Because an eccentric can be attached anywhere along a shaft, it is unnecessary to form any part of the shaft into a crank. Eccentrics are seldom used to transmit large forces because friction loss would be high; they are commonly used to drive the valve gears of engines.

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In psychoanalytic theory, an often unconscious mental process (such as repression) that makes possible compromise solutions to personal problems or conflicts. The compromise generally involves concealing from oneself internal drives or feelings that threaten to lower self-esteem or provoke anxiety. The term was first used by Sigmund Freud in 1894. The major defense mechanisms are repression, the process by which unacceptable desires or impulses are excluded from consciousness; reaction formation, a mental or emotional response that represents the opposite of what one really feels; projection, the attribution of one's own ideas, feelings, or attitudes (especially blame, guilt, or sense of responsibility) to others; regression, reversion to an earlier mental or behavioral level; denial, the refusal to accept the existence of a painful fact; rationalization, the substitution of rational and creditable motives for the true (but threatening) ones; and sublimation, the diversion of an instinctual desire or impulse from its primitive form to a more socially or culturally acceptable form. Seealso ego; neurosis; psychoanalysis.

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Mechanism may refer to:

• Mechanism (biology), explaining how a feature is created.
• Mechanism (chemistry), explaining a reaction pathway.
• Mechanism (philosophy), a theory that all natural phenomena can be explained by physical causes
• Mechanism (sociology), a set of rules designed to bring about a certain outcome
• Mechanism (technology), a device of which a mechanical joint is used
• Mechanism (engineering), a rigid bodies connected by joints inorder to accomplish desired force and motion transmission

See also

• Mechanism design, the art of designing rules of a game to achieve a specific outcome
• Mechanism of action, the means by which a drug exerts its biological effects
• Defence mechanism, unconscious mechanisms aimed at reducing anxiety
• Reaction mechanism, the sequence of reactions by which overall chemical change occurs
• Antikythera mechanism, an ancient Greek analog computer