Safety chain

1.

(Railroads) A normally slack chain for preventing excessive movement between a truck and a car body in sluing. Safety arch (Arch.) a discharging arch. Safety belt a belt made of some buoyant material, or which is capable of being inflated, so as to enable a person to float in water; a life preserver. Safety buoy a buoy to enable a person to float in water; a safety belt. Safety cage (Mach.) a cage for an elevator or mine lift, having appliances to prevent it from dropping if the lifting rope should break. Safety lamp (Mining) See under Lamp. Safety match a match which can be ignited only on a surface specially prepared for the purpose. Safety pin a pin made in the form of a clasp, with a guard covering its point so that it will not prick the wearer. Safety plug See Fusible plug, under Fusible. Safety switch See Switch. Safety touchdown (Football) the act or result of a player's touching to the ground behind his own goal line a ball which received its last impulse from a man on his own side; - distinguished from touchback. See Touchdown. Same as safety Safety tube (Chem.) a tube to prevent explosion, or to control delivery of gases by an automatic valvular connection with the outer air; especially, a bent funnel tube with bulbs for adding those reagents which produce unpleasant fumes or violent effervescence. Safety valve a valve which is held shut by a spring or weight and opens automatically to permit the escape of steam, or confined gas, water, etc., from a boiler, or other vessel, when the pressure becomes too great for safety; also, sometimes, a similar valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, to prevent collapse.