Patent GB-245426-A (GB)
Title: Improvements in or relating to internal combustion engine locomotives
IPC: B61C17/12
Filed: 1925-11-26
Abstract: 245,426. Invernairn (W. Beardmore), Lord, and Chorlton, A. E. L. Jan. 5, 1925, [Convention date]. Interlocking and guarding against wrong movements .and the like; hydraulic transmission. - In a locomotive for road or rail propelled by an internal-combustion engine through a change-speed gear and a reversing gear the fluid - pressure controlling means for the two gears are interlocked. Means are also provided for ensuring that (1) the reversing gear cannot be shifted from one operative position to the other unless the brakes are applied and the locomotive is stationary, and (2) the brakes cannot be released unless the reverse gear is in one of its operative positions. In the construction shown the change-speed gear is controlled by a valve M and the reversing gear by a valve L. The handle L<7> of the reversing valve carries a plate L<9> having two holes L<10>, L<11> corresponding to the forward and reverse drives. The fixed cover plate E<5> of the change-speed gear -valve carries a sliding pin O<5> pressed by a spring against the plate L<9>. When the reversing valve is in one of the gear positions the pin O<5> enters ,one of the holes L<10>, L<11> and its other end bears against a disc 0 carried by the valve handle 0'. Before the reversing valve can be rotated the valve M must be turned to its neutral position when a hole in the disc 0 is opposite the pin which can then be raised by a lever O<6> to clear the plate L<9> and free the reversing valve. The pin having entered the disc 0 locks the valve M, which cannot be moved until the reversing valve is left in one of the gear positions and the pin has entered the plate L<9>. The fluid controlling the valves passes from a pump A through an automatic pressure-regulating device A<7> to a distributing valve B leading either by pipe B<12> to the reversing valve L or by pipe B" to an automatic valve S and the hand-controlled gear valve M. The valve B is rotated by a rack B<8> on a member connected to the brakes, so that the fluid can only pass to the pipe B<12> and the reversing valve when the brakes are " on " and the parts are in the position shown in Fig. 1. From the pipe B<12> the fluid passes to a locking cylinder H<2> through a device F, which affords a passage only when the locomotive is stationary. The piston of the locking cylinder H<2> carries a pin H which normally locks a bar G<5> controlling the bevel reversing gear G. When pressure is applied under the piston the pin is raised and the bar released. However, this pressure cannot be applied unless a passage from a port H<5> through a plunger part of the bar G<5> is sealed. There are three of these passages G", G<12>, G<13> each adapted when in line with the port H<5> to be connected with one of three pipes (not shown) leading to the reversing valve L. When the valve position corresponds to the gear position of the bar G' the valve allows a free passage from the port H<5> back to the pump so that there is no pressure under the piston H<1>. When the valve is moved to another position this passage is sealed, the piston H' rises and frees the bar G<5>, and fluid passes through a pipe H<9> to the reversing valve and also to a cylinder B<10>, thus holding the brakes " on." The reversing valve has four ports J<5> - - J<8> controlling pipes leading to the ends of two cylinders K, K<2>, the pistons of which are connected to a floating lever K<4> operating the bar G<5> of the reversing gear. In the neutral position shown the ports J<6>, J' are open to pressure and the ports J<5>, J<8> to exhaust. If the valve is rotated clockwise the ports J', J<8> will be under pressure so that the piston K<3> will be moved to the right, the bar G<5> will be moved forward and the gear G<2> will engage with the gear G. When the bar G has moved to its new position the position of the bar will correspond to that of the valve and there will be a free passage for fluid through the port E<5>, the plunger G<6>, a pipe (not shown), and the valve L. The piston H<1> will accordingly be depressed by a spring H<3>, the pin H will lock the reversing gear in its new position, and a relief passage H<10> through the piston will be open for fluid from the reversing valve and the brake-locking cylinder B<10>, allowing the brakes to be released and the valve B to be rotated to supply fluid to the valves controlling the change-speed gear. The device F obstructing the pipe B<12> unless the locomotive is stationary comprises a fixed casing F<9>, a central part F driven by a rotating part of the locomotive and carrying a disc F<4>, and an annular part F<2> carrying a fly-wheel F<5> driven from the disc F<4> through springs F<6>. Ports in the parts F, F<2> are in line when the locomotive is stationary, but when the locomotive moves the part F is driven and the part F<2> lags behind during the accelerating period so that the fluid passage is closed. At a certain speed centrifugally-actuated weights F<7> clutch the two parts together with the ports out of line. During deceleration the flywheel overruns the disc F<4> and the ports are still kept out of line until the locomotive stops. In a modification, the device F comprises a pump driven from the locomotive wheels and acting on a spring- loaded piston affording a passage for the fluid only when the pump is stationary. As described in Specification 245,425, the valve S is controlled automatically by a centrifugal governor driven from a non-driving wheel, and controls the passage of fluid to the hand-operated valve M so that the gear ratio cannot be changed unless the speed of the locomotive is suitable. The four pipes D<1> - - D<4> leading from the valve S to the valve M, and the four pipes P<1> - - P<4> leading from the valve M to the change-speed gear, may each control one of the friction clutches of the epicyclic change-speed gear described in Specification 236,545, [Class 80 (ii), Gearing, Variablespeed &c.].