air governor (arguvernor)

A device, attached to pneumatic apparatus and machinery, for regulating the pre ure or delivery of air. air-grating (ar'grating), n. A grating protecting or forming a ventilating orifice in a wall or partition. See air - brick. air-gun (ar'gun), n. A gun in which condensed air is used as the propelling agent. The bore of the barrel is connected with a reservoir inclosed within or attached without the stock, into which air is forced by a piston or plunger fitted to the bore, or by an independent. Air-gun. condenser. When the trigger is pulled it operates a valve which permits the sudden escape of the whole or of a portion of the condensed air into the barrel at the rear of the ball or dart, thus projecting the latter. In some forms the propelling agent is a compre ed spring freed by the trigger. The reactive force of the spring com pre es the air which interposes between it and the projectile, and the air acts upon and projects the ball. air-heading (ar'hed ing), n. An excavation in a mine through which air is made to pa for ventilation. op 124 in part of a piston moving in a cylinder would become between the piston and the cylinder-head, so as to prevent the piston from making its full stroke. air-hoist (ar'hoist), n. Hoisting machinery (ar hoist), n. Ho erated by compre ed air, or by the creation of air- logged if air should enter the cylinder and remain a partial vacuum. It consists of a cylinder fitted with a piston, which is connected by ropes pa ing over pulleys with the platform of the hoist. See elevator and hoist.