Patent GB-245425-A (GB)
Abstract: 245,425. Invernairn (W. Beardmore), Lord, and Chorlton, A. E. L. Jan. 5, 1925, [Convention date]. Automatic speed or power control; hydraulic transmission.-In an internal-combustion engine locomotive a fluid-pressure system controlling the variable speed gear is itself controlled independently by hand and by means actuated automatically in accordance with the road speed of the locomotive. An automatic control of the fluidpressure system dependent on the engine speed may be imposed upon the road speed control. As described in Specification 245,426, reversing gear control is interlocked with the change-speed control and means are provided for ensuring that (1) the reversing gear control cannot be operated unless the brakes are applied and the locomotive is stationary, and (2) the brakes cannot be released unless the reversing gear is in an operative position. A pump A, Fig. 1, supplies the fluid for controlling purposes drawing it from a tank A' and delivering it past a regulating device A<6> to a valve B. When a valve port B<1> is in line with a port B<4> the fluid passes to an automaticallycontrolled valve C through which the fluid passes t) a hand-controlled valve E and from thence to pipes P' - - P<4> controlling the friction clutches of an epicyclic variable gear which may be that described in Specification 236,545, [Class 80 (ii), Gearing, Variable-speed &c.]. The valve casing C contains two concentric rotatable members V, W, the positions of which are governed respectively by the road speed and the engine speed. The pressure fluid enters the interior of the member W through a pipe C<5> and ports are so formed in the members V, W that, according to their positions, the fluid passes to one of the four passages C<1> - - C<4> leading to the hand-controlled valve E. Each of these passages corresponds to one of the positions of the change-speed gear and can be put into communication, in turn, through the valve E with the pipes P<1> - - P' in various combinations. The positions of the members V, W are determined by the similar mechanisms shown in Figs. 14 and 19. A shaft V<1>, driven from one of the non-driving wheels of the locomotive, drives the shaft X<1> of a centrifugal governor X and also reciprocates a plunger X<13> through worm gearing X<10> and an eccentric X<12>. The plunger bears against the base of a block X<8> carried by an arm X<6> controlled by the governor, the point of this block bearing against two toothed arms Y<2>, Y<3> swinging freely on a shaft Y<4>. Each arm carries a sector plate Y<5> having bevel teeth gearing with a bevel pinion V<15> on a rocking shaft geared at V<13> to the valve member V. When the road speed alters the governor 'sleeve moves and raises or lowers the block X<8>, the reciprocating movement imparted to the block by the plunger X<13> causing the block temporarily to disengage from the teeth Y<2>, Y<3> and so permit vertical movement of the block. As the sectors Y<5> are geared together by the pinion V<15> they rotate in opposite directions to allow both the arms Y<2>, Y<3> to engage the block in its new position. The pinion V<15> and therefore the valve member V are thereby rotated to take up a new position corresponding to the altered road speed. The member W is controlled in a similar manner from an engine-driven shaft W<10>. When the locomotive is at rest and the valve E is moved to the first gear position pressure fluid is supplied from the valve C through port C<1> and the valve E to the first gear clutches and the locomotive is driven. The valve members V, W are rocked to positions corresponding respectively to the road and engine speeds. When the usual road speed indicator shows the driver that a change can be made to second speed he moves the valve E to the corresponding position and slows down the engine. This rocks the member W relatively to the member V and admits pressure fluid to the port C<2>, thus actuating through the valve E the clutches for the second speed. The same procedure is followed for the other speeds. In a modification in which the valve C is controlled simply by the road speed this valve comprises a sliding piston moved to admit pressure fluid to the ports C<1> - - C<4> by a governor driven from a non-driving wheel. A valve B which directs the pressure fluid either to the change-gear valves C, E or to a valve H controlling the reversing gear G, a cylinder B<10> connected to the brakes, and a valve F controlled by a moving part of the locomotive are all described in Specification 245,426.