Vacuum brake
Vacuum Vac"u*um, n.; pl. E. {Vacuums}, L. {Vacua}. [L., fr. vacuus empty. See {Vacuous}.] 1. (Physics) A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the interior of a closed vessel, which has been exhausted to a high or the highest degree by an air pump or other artificial means; as, water boils at a reduced temperature in a vacuum. [1913 Webster]

2. The condition of rarefaction, or reduction of pressure below that of the atmosphere, in a vessel, as the condenser of a steam engine, which is nearly exhausted of air or steam, etc.; as, a vacuum of 26 inches of mercury, or 13 pounds per square inch. [1913 Webster]

{Vacuum brake}, a kind of continuous brake operated by exhausting the air from some appliance under each car, and so causing the pressure of the atmosphere to apply the brakes.

{Vacuum pan} (Technol.), a kind of large closed metallic retort used in sugar making for boiling down sirup. It is so connected with an exhausting apparatus that a partial vacuum is formed within. This allows the evaporation and concentration to take place at a lower atmospheric pressure and hence also at a lower temperature, which largely obviates the danger of burning the sugar, and shortens the process.

{Vacuum pump}. Same as {Pulsometer}, 1.

{Vacuum tube} (Phys.), a glass tube provided with platinum electrodes and exhausted, for the passage of the electrical discharge; a Geissler tube.

{Vacuum valve}, a safety valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, in order to prevent collapse.

{Torricellian vacuum}. See under {Torricellian}. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Vacuum brake — The vacuum brake is a braking system used on trains. It was first introduced in the mid 1860s and a variant, the automatic vacuum brake system became almost universal in British train equipment, and in those countries influenced by British… …   Wikipedia

  • vacuum brake — noun : a brake using a partial vacuum in its operation; specifically : an automobile brake in which the braking pressure applied by the operator is augmented by the negative pressure of the suction on the intake manifold …   Useful english dictionary

  • vacuum brake — /ˈvækjum breɪk/ (say vakyoohm brayk) noun a type of brake used on railway trains, motor vehicles, etc., operated by a vacuum system …   Australian English dictionary

  • vacuum brake — noun a railway vehicle brake operated by changes in pressure in a pipe which is kept exhausted of air …   English new terms dictionary

  • Vacuum brake — Вакуумный тормоз …   Краткий толковый словарь по полиграфии

  • vacuum brake booster — A device directly connected to the master cylinder and mounted on the engine side of the bulkhead, which uses engine manifold vacuum to produce additional braking force …   Dictionary of automotive terms

  • Vacuum — Vac u*um, n.; pl. E. {Vacuums}, L. {Vacua}. [L., fr. vacuus empty. See {Vacuous}.] 1. (Physics) A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the interior of a …   The Collaborative International Dictionary of English

  • Vacuum pan — Vacuum Vac u*um, n.; pl. E. {Vacuums}, L. {Vacua}. [L., fr. vacuus empty. See {Vacuous}.] 1. (Physics) A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the… …   The Collaborative International Dictionary of English

  • Vacuum pump — Vacuum Vac u*um, n.; pl. E. {Vacuums}, L. {Vacua}. [L., fr. vacuus empty. See {Vacuous}.] 1. (Physics) A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the… …   The Collaborative International Dictionary of English

  • Vacuum tube — Vacuum Vac u*um, n.; pl. E. {Vacuums}, L. {Vacua}. [L., fr. vacuus empty. See {Vacuous}.] 1. (Physics) A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the… …   The Collaborative International Dictionary of English

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”