5678. Dewson, E. H., and Brown, T. R. April 15. Couplings, automatic; couplings, operating from engine or train.-Relates to automatic couplings of the twin interlocking type in which fluid-pressure actuated mechanisms are provided for releasing the coupler locks. The main improvements are as follows: (a) A connexion is provided between the fluid-pressure conduits on the two coupled vehicles such that the release of both locks can be effected by operation of the controlling-valve on either vehicle. (b) The coupling is so combined with a coupling for electric train-line circuits of the type having a sliding contact-carrier that the carrier may be withdrawn before the locks are released, thus preventing injurious sparking when the vehicles are separated. (c) A locking- device is provided for each carrier to prevent its accidental withdrawal due to leakage of pressure fluid. (d) Shutters operated by the movements of the carriers are provided to close the openings in the face of the coupler-head when the carrier is withdrawn. (a) Fig. 1 shows part of draught coupling in sectional plan, and an electric coupling partly in vertical section. The draught-coupling members 3 engaging by horizontal swing, are clamped together when coupled by a pivoted lock 4 on each coupler-head bearing against a surface 5 on the opposing member 3. Each lock 4 is connected by a rod 7 to a piston 6, behind which is a spring 8 serving to hold the parts in the locking position until fluid at a sufficient pressure is admitted to the front of the piston through passages 10, 11, 12 by operation of a controlling valve 9. The passages 11 in the two coupler-heads communicate through hollow tappets 31. (b) The opposing casings 15 of the electric coupling, each supported below the draught coupler-head are guided into position in coupling by spigots 79 engaging sockets 78, Fig. 4. Within each casing is provided a single or double row of contacts 16 each connected with a corresponding wire of the train-line circuits, other contacts 17 being provided for closing local circuits on each vehicle. The contacts 16 on two coupled vehicles are adapted to be connected by one or other of two sliding contact-carriers 18, one mounted in each casing. In the construction shown in Figs. 1 and 4, the carriers are moved into operative position automatically, when the vehicles meet, by the action of the tappets 31. For this purpose, each carrier 18 is operated through arms 25, 24, from a piston 23 in a cylinder 22 communicating by a passage 28 with an exhaust valve 29 and with a valve 26 for admitting fluid pressure through a passage 27 from a passage 48 in communication with the train-pipe. The valve 26 is normally held closed by a spring 30 and abuts on the stem of the valve 29 mounted on an inner portion of the tappet rod 31 telescoping in the outer portion against a spring 32. When two vehicles meet, one of the rods 31 yields before the other to close the corresponding valve 29 and to open the valve 26, whereupon fluid-pressure is admitted to the cylinder 22 to operate the carriers 18 against the action of springs 40. In this position the contacts 16 engage with cross-connected contacts 19, 20 on the projected carrier, as shown in Fig. 1. In the inoperative position, the contacts 17 engage with contacts 21 on the carriers. When the valve 9 is operated to release the locks 4, such release is preceded, owing to the restricted nature of the passages 11, 12, by the movement of a piston 50 to close a valve 41 connecting the passages 27, 48, and to open the passage 27 to exhaust through a port 49, thus exhausting the cylinder 22 and allowing the spring 40 to withdraw the carrier 18. By operating the valve 9 to admit fluid at a pressure insufficient to release the locks 4, the carrier may be withdrawn without releasing the locks. (c) In case of leakage of pressure fluid from the passage 48, a piston 54 in communication therewith is moved by a spring 58 to allow a spring catch 59 to engage a notch 64 in the stem of the piston 23, which, with the carrier 18 connected to it, is thus locked in operative position. At the same time a shoulder on the rod of the piston 54 presses a clamping-arm on the stem 62 of the valve 29 to prevent its opening. (d) Shutters 65. 66, carried by arms 67, 68 pivoted to the side walls of the casing 15, are adapted to take the positions shown in Figs. 1 and 8 by the action of cam-surfaces on the arms and on the carriers 18, or the shutters may be spring-controlled in one direction. Various modified arrangements of the mechanism are described. In one form, the valve controlling the withdrawal of the carrier 18 is located between the valve 26 and the cylinder 22, and release of the locks 4 is prevented until the carrier has been withdrawn, by providing the passage leading to the piston 6 with a valve closed by a piston which is spring-pressed against the carrier, until, when the carrier is withdrawn, the piston enters a recess in the carrier and opens the valve. Fig. 11 shows a modified arrangement with the connections from a controlling-valve 113 for effecting the various operations. The valve has ports 115, 116, 117 adapted, in the neutral position, to connect pipes 112, 118 with an exhaust port 119, and has a cavity 120 for connecting a fluid-pressure supply pipe 121 to the pipe 112 or to the pipe 118. The pipe 112 leads to a chamber 110 in front of a piston 109 and thence communicates by a passage 125 with a chamber 124 fitted with a hollow sliding tappet 122 adapted to abut on a corresponding tappet on the other vehicle to place the two chambers 124 in communication through the tappet orifices and through ports 129. The pipe 118 leads to the cylinder 95 for controlling the contact-carrier 91. The cylinder 95 communicates by a pipe 128 with the chamber 124 through a valve 127 under the control of the spring of the tappet 122. When the vehicles meet and the draught couplings have engaged automatically, one of the carriers 91 is projected by operating the corresponding valve 113 to connect the pipes 121, 118, thus admitting fluid pressure to the cylinder 95. The carrier 91 is locked in its projected position by the horizontal arm of a pivoted member 106, of which the vertical arm engages in a slot in a rod 108 mounted to slide under spring control in a chamber 140 behind the piston 109, the rod carrying a valve 141 connecting the two sides of the piston. A tappet rod 111 carried by the piston may be manually pressed to release the carrier 91 from the member 106 when the valve 113 has been returned to neutral position. To effect the release of the carrier, and subsequently also of the coupler locks, the valve 113 is operated to connect the pipes 121, 112, thus admitting fluid-pressure to both chambers 110 and releasing the projected carrier 91. Each carrier is then returned by its springs to normal position, in which a projection 143 on the carrier engages a projection 142 on the member 106 and the valves 141 are held open to admit fluid pressure from the chambers 110 to the chambers 140 and thence through pipes 139 to the coupler-lock releasing-mechanism. When the vehicles separate, the valves 127 are free to open to vent fluid from the pipes 128 to the atmosphere. Fig. 23 shows a further modified control svstem in conjunction with means for isolating the fluid-pressure brake system of a vehicle or train section in the act of releasing the coupler locks. The controlling valve 172 has ports 180, 181, 182, shown in neutral position in Fig. 24, adapted to connect a pipe 187 with a pipe 171 or with a pipe 186, and the valve stem carries a switch arranged to close the electric train-line circuits only when the valve is in the neutral position. The pipe 171 leads to the cylinder 167 for controlling the contact-carrier, and the pipes 186, 187 lead respectively to passages 195, 197 in a valve device 188, the passage 197 communicating by a pipe 191 with a fluid-pressure reservoir 192, and the passage 195 by a pipe 196 and a check-valve 199 with a pipe 178 leading to the tappets 122. To project the carrier, the controlling valve is operated to connect the 'pipes 171, 187. The carrier is locked in the projected position by a spring-controlled lever 173, adapted to be operated against the spring action by admitting fluid pressure to a piston chamber 177 in communication with the pipe 178. To withdraw the carrier and subsequently to release the coupler locks, the controlling-valve 172 is operated to connect the pipes 186, 187, thus admitting fluid pressure to the pipe 178 to operate the lever 173, whereupon the carriers are returned by their springs to normal position, a projection 174 on each carrier operating the lever 173 to open a valve 205, thus admitting fluid pressure from the pipe 178 to a pipe 206 leading to the coupler-lock releasing mechanism. The fluid pressure is maintained in the pipes 196, 178 after the controlling-valve 172 has been returned to neutral position by the opening of a valve 190 connecting the pipes 191, 196 by the action of the fluid pressure in the pipe 195 on a piston 189. In a modification, the controlling valve 172 is incorporated in the casting of the valve 188. The fluid pressure in the pipe 196 acts on piston 200 to close a valve 201 connecting the brake-pipe 202 on that vehicle with the train-pipe 203. The valves 156 of the brake-pipe coupling are opened against the action of springs 157 by abutting tappets 158 when two vehicles come together, and are each locked in the open position by a spring-pressed piston 159 normally balanced as to fluid pressure. The fluid pressure behind the piston is arranged to be vented by the act of releasing the coupler-locks, and the valves 156 are then free to be closed by their springs. In case of accidental separation of the vehicles, the valves are held open by the pistons 159, and an automatic application of the brakes is effected.