Patent GB-191212815-A (GB)
Title: Improvements in and relating to Apparatus for Locking and Unlocking Doors of Railway Carriages.
Inventor: WILSON JOHN
IPC: E05B65/38
Filed: 1912-05-31
Granted: 1912-12-19
Abstract: 12,815. Wilson, J., [Wilson, J. H.]. May 31. Pneumatically-operated fastenings.-The invention relates to means for simultaneously locking and unlocking railway-carriage doors, as described in Specifications 6800/09, 4031/11, 17,945/11, and 17,946/11 and comprises improvements in the vacuum-operated motor, in the arrangement of the levers that communicate the motion of the piston-rod to the fastening- devices, and in the latch employed, and also provides an emergency unlocking-means. In a motor of the type shown in Fig. 1, a slidable piston-like member c is mounted on the main piston-rod a<10>, whereby the valve a' at the head of the cylinder a is kept open during the greater part of the outward stroke and closed for the greater part of the inward stroke, and is only closed or opened respectively near the ends of the strokes, thus securing a more powerful operation of the piston than heretofore. When a vacuum is established in the train-pipe, which communicates with the cylinder a through the passage a<11>, the atmospheric pressure maintained above the piston a' by means of the open valve a<5> forces the piston down over the rolling piston-ring a<2>. The valve a<5> is maintained open until near the end of the stroke by means of an abutment on the subsidiary piston-rod c, the space above which is at the same low pressure as the space a<9>, being connected therewith by the passage c<5>; while the reverse side is still at atmospheric pressure, being in communication with the space a<7> through the passage c<8>. Near the end of the stroke, the part c'of the subsidiary piston engages with the part d<2> of the piston a, and as the hole a<4> comes below the rolling piston-ring a<2> immediately afterwards, the space above the piston a<1> is exhausted and the valve a<5> closed by the external pressure. On breaking the vacuum in the train-pipe, the main piston moves upwards, the valve being kept open in a similar manner until near the end of the stroke. Instead of being in the form of a piston, the part c may be a spring-pressed sliding rod mounted upon the main piston-rod, the valve operation being similar to that described. The downward movement of the piston-rod a<10>, through the intermediary of the pivoted cranked levers i, ,j shown in Fig. 7, communicates a downward movement to the lever h<1> pivoted on the longitudinal shaft h, a projection on which thereby lowers the sliding bolt l, Fig. 16, whose lateral projection l<6> engages with the latch m' of the lock m and so locks the door. On destroying the vacuum in the train-pipe, the piston-rod moves upward and the sliding bolt l is raised, thus removing the obstruction l<6> to the opening of the door. In a modification, the motor is trunnioned with its piston-rod upwards, and a modified arrangement of levers is then employed to effect the movements of the sliding bolt l; or by another arrangement of levers, the downward movement of the motor piston-rod is used for operating locking-devices on both sides of the carriage. For the emergency unlocking of the doors, a vent-valve o, Fig. 18, of the type in which a pivoted flap is held down upon the end of a pipe by the vacuum in the pipe, is provided on a branch g<*> from the train-pipe, this valve being operated by means of a projection o<1> on a rod o<2> running across the carriage and adapted to be rotated by means of the chain o<7 >of the usual emergency communication. By pulling the chain, the rod o<2> is partly rotated, thus opening the valve o, whereby the vacuum throughout the train-pipe is destroyed and the doors unlocked. Another valve is provided when a train-pipe for each side of the carriage is employed. Striking-plates. - In connexion with the, handleless lock, Figs. 16 and 17, the projection l<6> has its lower surface bevelled, and a spring- pressed latch-lock r is provided so that when the sliding-bolt l is down and the door is afterwards slammed, the latch-lock r is depressed, to enable the latch m' to return to its horizontal position, and then rises to prevent any further rotation of the latch.