Patent GB-190600902-A (GB)
Title: Improvements in Pneumatic and like Railway Signalling Systems and Apparatus therefor.
Inventor: WOODMAN ARTHUR
Filed: 1906-01-12
Granted: 1907-01-10
Abstract: 902. Woodman, A., [Cosserat, W. A. P.]. Jan. 12. Points and switches.-A non-automatic system for operating, locking, and detecting railway points and operating signals in connexion therewith, which is an improvement on that described in Specification No. 16,277, A.D. 1904, comprises improved pointoperating cylinders, Fig. 2, improved point locking and detecting apparatus, Fig. 3, and an arrangement of valves of the type described in Specification No. 183, A.D. 1900, and in the abovementioned Specification, improved hand-levers, Fig. 11, for connecting the operating-pipes to the source of pressure, which levers may be provided with locking - cylinders of the type described in Specification No. 27,624, A.D. 1902; and an improved main controlling hand-lever, Fig. 13, which may be interlocked with a ground frame or the like by removable key so _ as to close the hand-lever frame and allow the key to be used for unlocking aground frame or the like. The hand-lever frame L consists of a series of levers a ... h, shown in detail in Fig. 11, interlocked by tappets 63, and operated by pulling out a slide 51 which has an enlarged part 57 normally butting against a seating and so shutting off the operating-pipe 56 from the channel 49, which is connected through the valve X to the pressure reservoir X<1>. In its normal position, the lift valve 54<a> is in its low position and closes the pipe 56 and opens the chamber 48 to atmosphere, thus preventing operation of any apparatus by leakage pressure. When the slide 51 is pulled out, the valve 54<a> is lifted by the inclined face 52, and the plug 57 passes to the right of the port 49. The. volume of air in the chamber 58 is exhausted through the ports .62, 60, 61, of which the last opens to atmosphere after the plug 57 has passed the port 49. Two slightly different arrangements of conduits and valves are shown at the left and right hand ends of Fig. 1. To set a road on the through line from right to left, the lever f is pulled, and pressure passes through the pipe line to the cylinder 2 of the locking-apparatus for the points,' shown in detail in Fig. 3, forcing the piston 27 to the left if it is in its right-hand position, and unlocking the stretcher bar 30 through the bar 3, which is connected to the bar 4 and also to the locking-bar 7 and the selector valve 5. When the points are unlocked, pressure passes along the pipe 19 to the point-operating cylinder 1, Fig. 2, which, if required, moves the points over, and pressure then passes to the pipe 15 and to the underside of the relay valve 13. The piston 27 is then forced to the end of its stroke and locks the points in their required position, and pressure passes through the pipe 35 to the underside of the relay valve 17. The lever c is next operated to set the points at the left-hand end of the section, and, after the points are set, the relay valves 13, 17 are lifted. At this end one relay valve is shown in conjunction with a three-way plug valve instead of two relay valves at the right-hand end. The home-signal lever g is next operated and passes air to the cylinders f<1>, b<1>, locking their respective levers f, e, b, and to the selector valve 5 described in Specification No. 183, A.D. 1900, through a relay valve 13 to the cylinder 20 of the home signal, through the latter and the plug valve 42 to the cylinder 21 of the outer home signal, and through this to the relay valve 16. The distant signal h is then operated, and pressure passes through the relay valve 17 and the relay valve 16 to the cylinder 22 of the distant signal. Similar operations are gone through for the points and signals of the loop line and for transits from left to right. The lever frame L may be put out of action by means of the mastervalve X, Fig. 12, which may be locked in this position ; the key may be used to unlock a ground frame or the like. The end of the slide 67 carries a plug 68 which shuts off the port 50<a> from the chamber 58<a> and-the annular port 49 when the slide is pulled out. The projections 73, 73<a> on the slide 67 move in longitudinal grooves in the valve casing which prevent turning of the spindle until the valve is pulled completely forward so that they may enter transverse grooves 75<a>. The spindle is normally held against turning by a spring pawl 76 entering a notch 72<b>, from which it is lifted by the key 7l,which then turns the spindle until the pawl 76 enters the notch 77<a> and so secures the spindle in its new position, in which position the key 71 maybe removed for use at a ground frame or the like. The key is locked in the lock housing when the spindle 67 is turned into its normal position.