20,872. Belfield, R., [Doyle, J. S., and Brown, T. R.]. Oct. 12. Couplings, automatic; slipping vehicles. - In an automatic coupling of the type in which twin coupler heads engage by an horizontal swinging movement and are clamped together by pivoted latches 5, Fig. 1, engaging vertical plane faces on projections 3 formed on the heads, the latches 5 are held in the engaging position by springs and are withdrawn, for releasing the coupling, by fluid pressure admitted behind the pistons 7. The brake-pipe couplings are formed on the car coupling, the joint being made tight by gasket rings 15 which meet when the cars are coupled, the valves 16 being at the same time opened by contact of their stems with each other. The valves 16 are prevented from reclosing, if the cars should separate accidentally, by spring detents which are, however, withdrawn by pneumatic pressure when the cars are uncoupled by the admission of compressed air to the latch pistons through the pipes 10; or instead of the spring detents the valves may be held open by the pressure of compressed air on pistons fitted at the ends of their stems and controlled to permit the valves to close, when the cars are uncoupled, either by hand operation of an exhaust cock or by the automatic operation of a valve associated with the coupler latch releasing-mechanism. Valve mechanism for supplying fluid to the pipe 10 to release the coupling is shown in Fig. 10. It comprises an admission valve 26 and an exhaust valve 28 having abutting stems so that one is opened when the other is closed. When a solenoid 31 is energized its core closes the exhaust valve 28 and opens the valve 26 so as to admit air from a suitable source 27 to the pipe 10. The solenoid is energized by movement of a switch lever 35 so as to bring the arm 34 over a contact 38, and the switch arm is automatically locked in that position by a notched bar 45 attached to the core of the solenoid. When the unlatched couplings become fully disengaged by separation of the cars the electric coupling for the circuit through the solenoid is also disengaged and the solenoid is de-energized. The valves 26, 28, and the solenoid core are then raised by a spring 32 and the switch arm 34 returns automatically to the position shown by the action of a spring 46. The switch contacts are so arranged that when the switch arm 34 on any car is turned to unlatch the car couplings the propelling-circuit between that car and others in rear of it is broken while the propelling-circuit on that car is still closed to enable the motor to move the car away from the others. A coupling for the electric conductors between the cars is bolted to the lower side of the car coupling. It comprises a casing consisting of an upper portion 53, Fig. 9, fitted with fixed contact fingers 55, 57 and a lower portion 54 containing a spring-pressed slide 58 carrying a series of cross-connected contact bars 59, 60 adapted to engage the fingers 55 to close the main circuits through the train when the cars are coupled, and carrying also contact bars .61 adapted to engage the fingers 57 to close local circuits on the cars when uncoupled. The slide is attached to the piston-rod of a pneumatic cylinder fitted below it in the casing. A sliding rod projecting slightly from the casing impinges on a similar sliding rod projecting from the casing of the adjacent car coupling when the cars meet. One of the rods is pushed in by the impact and operates valve mechanism admitting compressed air to the cylinder, which then forces the slide 58 into the casing of the adjacent car and completes the coupling of the conductors as shown. Gasket packing 79 between the casings excludes dust.