Improvements in or relating to apparatus for stopping run-away trams in mines and other places

摘要

214,713. Hadfields, Ltd., and Rodgers, I. Jan. 24, 1923. Track apparatus for stopping trains. - Railroad vehicles travelling above a predetermined speed, e.g. trucks running away on a gradient, are stopped by means of a hook a, which is automatically raised into engagement with a truck axle p, the hook being connected to a cable v drawn from a storage drum x to which an increasing brake-pressure is applied as the cable unwinds. Normally, the hook a is in a lowered or inoperative, position, supported on a table b carried by the upper end of a cylinder c slidably mounted on a hollow pillar d and retained in its lowered position, against the pressure of a spring housed within the pillar d, by a pivoted detent g the lower end of which engages a nose h on the cylinder c. A pivoted arm o the lower end of which carries an adjustable weight s extends into the path of the axles &c. of the truck. At normal speeds the impacts of the axles give the arm o a limited idle swinging movement, but when the speed exceeds the predetermined limit the arm o is moved to an extent whereby its lower end is driven against the upper end of detent g. The cylinder c is thus released and is raised by the spring to bring the hook a into operative position. As the cable v is drawn from the drum x, a worm gear 5, 6 driven through gear wheels 2, 3 from the drum axle, causes an arm 13 to exert an increasing pressure on a brake-band 8 which retards unwinding of the cable. A contact arm 14, also operated by the worm gear 5, 6, closes an alarm circuit 15 to give a warning to the engineman and to the station nearest to the apparatus.