Patent GB-190725377-A (GB)
Title: Improvements in or relating to Train Control Apparatus.
Inventor: MITCHELL EDWARD ALBERT
Filed: 1907-11-15
Granted: 1908-11-16
Abstract: 25,377. Mitchell, E. A. Nov. 15. Brakes.-Relates to means for reducing the speed of vehicles at predetermined points on the route, such as curves and inclines, if the speeds exceed the limits set for the particular points. The apparatus comprises a governor responsive to the speed of the vehicle, and a device on the track or a device carried by the vehicle and influenced by the state of the track. In the arrangement shown in Fig. 1, the sleeve g<1> of the governor g is driven from the motor or axle of the vehicle by gearing h. The rod f is depressed, and, if the speed exceeds the limit for that point, the insulated brush d contacts with a ramp a, which is in electrical connexion with the supply conductor c. An electro-magnet p<2> is energized, pulls over its armature p<1>, and so releases a spring-operated lever p, which puts the members n, n<1> of a clutch into engagement. The shaft m is continuously rotated through gearing k from the sleeve g<1>, and, when the device operates, the threaded shaft o is also rotated. The nut o' is moved axially, and causes the forked rod o<5> to rock the shaft o<6>. This movement may trip a lever, attached to the handle of the motor controller or to a valve communicating with the brake system. The mechanism between the electromagnet and the rock-shaft o<6> may be modified. A guide rail o<2> is provided. The continued travel of the nut o<1> may be utilized to reset the device. A wheel q on the nut engages an arm p<3> and puts the clutch member n' and armature p<1> into their original position. To return the motor controller or brake valve to its original position, the screwed shaft o must be rotated backwards by the wheel r. The energizing current may be supplied by a battery carried by the locomotive. In the modification shown in Fig. 3, the shaft u<1> is rocked by a lever t if this lever is depressed to such an extent by the governor g that its lower end strikes the ramp a. The movement of the shaft u<1> may be used to reduce the speed in any convenient manner. The ramps employed vary in height according to the limits of speed set for the various points. For use on tramways where track ramps would not be permitted, a pendulous inertia device may be arranged to co-operate with the governor. Fig. 5 shows the application to controlling the speed in descending an incline. The end t<2> of the rod t is depressed by the governor into a slot in the weight v. This weight is pivoted at v<1> and swings about this point on an incline. If the speed is too great for the incline the shaft u<1> is rocked as before. Fig. 6 shows a modification of this construction, in which the engagement of the end of the rod t with the pivoted weight v, on the operative conditions as to speed and incline being attained, is electrical instead of mechanical. A sphere w runs on an insulated segment v<2> and completes a circuit when it contacts with plates w<1>. The control may be effected at different speeds for different inclines by stepping the plates w<1>as shown. A recording-instrument may be used for indicating whether the device has come into operation.