Patent GB-389506-A (GB)
Title: Improvements relating to traffic controlling apparatus for railways and the like
IPC: B61L23/24
Filed: 1931-09-17
Abstract: 389,506. Token systems for railwaytraffic control. ROBERTS, W. S., Newby, Ruff Lane, Ormskirk, Lancashire, and RAILWAY SIGNAL CO., Ltd., 40, Broadway, Westminster. Sept. 17, 1931, No. 26068. [Class 105.] An auxiliary token forming an authority for occupation by a trolley working party or for controlling swing bridges, level-crossing gates, or branch line traffic, may be inserted in any one of a number of auxiliary control instruments located along the section, or in the main control instruments at the ends of the section, to permit return to the normal control by the main instruments. When the auxiliary token is removed from the main or auxiliary instrument it alters the normal connection through the section transmission line so that the main instruments are out of phase and cannot now be used to permit normal working. The auxiliary token may control the release of the working-party trolley or its power drive. The auxiliary instrument is similar to the control instruments described in Specification 260,010, [Class 105, Railway signals &c.], and is shown in Fig. 2 with a detail thereof in Fig. 7. The auxiliary token is of key form such as described in the Specification referred to or in Specification 367,451, and is adapted, when inserted in the auxiliary instrument, to actuate a pin tumbler lock barrel 5 whereby a commutator 10 is rotated to restore the transmission line connection between the main instruments to normal. The auxiliary token can only be withdrawn from the auxiliary instrument if the main instruments are normal so as to give the proper polarity of transmission line current to energize a release magnet for a locking disc 7 fixed to the pin tumbler lock barrel 5 ; withdrawal of the auxiliary token actuates the commutator 10 to alter the line connection and so to put the main instruments out of phase. The locking disc is shown in Fig. 7 in the free position ; when the auxiliary key token is inserted and turned the locking projection 27 on the magnet armature drops behind the disc abutment 23, being positively forced down by a tooth 26 on the disc 7. The disc 7 carries a cam 8 with a depression 22 which permits the pivoted electromagnet 14 to approach its armature 20 which is thus brought within range and, if the current polarity is correct, lifted to permit the reverse rotation of the look barrel for withdrawing the auxiliary token. A spring device 13 urges the commutator 10 to each of its limit positions. A telephone can be plugged in at 30 to be connected with the line through condensers. The auxiliary key token may control the release of a trolley by being inserted into a duplex lock fixed on the trolley or attached thereto by a chain, and then being operated to free the other key which can then be withdrawn from the lock ; this other key is chained to a fixed post. The trolley must be therefore removed from the track to permit this other key to be re-inserted in the duplex look to release the auxiliary token which can then be inserted in the auxiliary or main instruments to restore normal working. The auxiliary token may comprise two parts screwed together each having a key portion which may be used to free a trailer and a trolley respectively. The auxiliary instrument then, as shown in Fig. 2, has two interlocked lock barrels 5, 46, which must have the two key portions inserted before the auxiliary instrument can be operated to restore normal working. The chained keys are slidingly retained in collars chained to the posts and the collars are engaged by shoulders on the duplex lock, so that the key and lock barrel cannot be subjected to any stress. In a modification a portable auxiliary instrument, similar to the above auxiliary instrument but having some additional mechanism in its base, is used which is adapted to be placed on any one of a number of posts in the section, each post having a commutator device controlled by two pin tumbler lock barrels. Fig. 18 shows a sectional plan through the lower portion of the portable instrument, and Fig. 23 a rear view of the commutator device on the post. In the normal state the segments 77 of these commutator devices bridge the fingers 76 to complete the transmission line of the section directly, but when the auxiliary portable instrument has been locked on a post the fingers 76 are engaged by segments 74 which are in connection through plug pins 50 with the commutator 10 of the portable instrument so that the transmission line is completed through the commutator of the auxiliary instrument. The base of the instrument contains a slide 64, with handle 65 whereby a rod 55 is longitudinally displaced by the slide 64 engaging a disc 58 fixed to the rod 55 ; the disc is notched to slide over a fixed rib and cannot therefore be rotated until the rib is cleared. The rod is slotted and towards the end of its movement displaces a plunger 51 carrying the plug pins 50 which are thus projected to engage the look barrel 69 of the commutator apparatus on the post. The projecting end of the sliding rod 55 is formed as a key to fit the pin tumbler lock barrel 69 on the fixed post while the other end is fitted with a lug 62 to engage a slot 61 in a sleeve which can be rotated by the milled head 63. The lock barrel 69 is however interlocked with a lock barrel 70 and cannot be rotated until the auxiliary token has been inserted through the opening 68 in the base of the portable instrument and operated the lock barrel 70 ; the milled head 63 is then turned to rotate the rod 55 and plunger 51, the pins 50 of which turn the lock barrel 69 and so alter the transmission line connection. The lock barrel 70 is restored to its first position and the auxiliary token withdrawn therefrom so as to lock the barrel 69 in its new position and the auxiliary token is now inserted in the portable instrument proper and actuating the commutator 10 thereof is locked therein to restore the main instruments for normal working.