176 



CONTINUOUS IlAfLWAY BKAKES. 



working them in dorivcd from tlie manual powor of the 

 guard, applied to a hand-wheel in the guard's van, the power 

 being applied by suitable gearing, with a certain mechanical 

 advantage, to the " brake rigging," by which the blocks are 

 brought into frictional contact with the tiros of the wheels, 

 a resistance being thus set up which serves to disperse the 

 " accumulated work " of the train. 

 A second class, — 



Glaus IT. 

 Contains those brakes in which the " force " for working 

 the "brakes" is the "kinetic energy" of the train, which, 

 by means of suitable gearing, worked from a friction roller 

 on the rear axle of the tail brake-van, is made to revolve 

 a drum, on the shaft of which a chain is wound ; the shorten- 

 ing of the chain raises a pulley, fitted to the etid of a bell- 

 crank lover on each carriage, under which pulley the chain 

 is passed ; inclined thrust rods, linked to the vertical arm 

 of the bell-crank lever, transmit the motion to the levers 

 carrying the brake blocks, which are- thus applied to the 

 tires of the wheels. 



In order to apply the brakes, it is only necessary to bring 

 the friction drum, on whose shaft the chain is coiled, into 

 frictional contact with the friction roller on the brake-van 

 axle, for which the device shown on the " friction rollers " 

 of Clark's brake is provided. 



It will bo seen, that should the train become parted, and 

 the chain broken, the moans of applying the brake is gone, 

 as the chain would have nothing to tighten against. 



Class III. 

 Colli ains those brakes in which the force for working the 

 brakes is obtained by destroying a certain condition of 

 " air pressure," of " liquid pressure," or of vacuum, which. 



