Patent GB-190902382-A (GB)
Title: Improvements in Railway Signalling.
Inventor: MARDON JOHN WILLIAM
IPC: B61L13/02
Filed: 1909-02-01
Granted: 1910-01-27
Abstract: 2382. Mardon, J. W., and Hudson, J. G. Feb. 1. Track apparatus actuating signals other than on trains ; visual outdoor signals ; audible signals ; crossing-gate signals.- A. mechanically operated crossing - gate signal comprising a semaphore 53, Fig. 1, and a bell f o r g i v i n g warning of the approach of trains, is operated by three sets of treadle apparatus, two of which 1, 1<a> are situated some distance away on opposite s i d e s of the signal, and are actuated by an approaching train to set the signal to 'danger,' the third 80 being situated near the s i g n a l for the purpose of resetting it to 'safety' when the train passes. The outer t r e a d l e s are designed to be operative when the train passes in one direction only. Each treadle apparatus for setting the signal to 'danger' comprises inclined contact bars 1, 2, Figs. 10 and 12, the outer end of the bar 1 having a pin-and-slot connexion with the rail ; and the outer end of the bar 2 is pivoted to the rail. Upon their inner ends, the bars overlap and have a pin- and-slot connexion. A part 20 is pivoted at 21 to a part 19, the bottom of which is pivoted to an horizontal tilting lever 13 which pulls the signaloperating rope. The bars 1, 2, are connected to the part 20 in such a manner that when a train passing in the direction of the arrow depresses the treadle-bars 1, 2, the part 20 is thrust downwards, thereby depressing the part 19 and tilting the lever, but when a train passes in the opposite direction the part 20 turns clockwise about the pivot 21 and the part 19 is not moved. The treadle apparatus for resetting the signal to ' safety' is similar to the above, but of simpler construction, as it is not required to be inoperable at any time. It comprises bars 80, 81, Fig. 13, pivoted to a vertical bar 87 hinged to a tilting lever 88. The semaphore and bell-operating device is shown in Fig. 2. Rope sheaves 28, 34, Figs. 2 and 17, are mounted side by side at the foot of the signal post 44. They are connected together by a ratchet so that either of the sheaves may revolve freely in one direction, but, when revolved in the other direction, it operates the other sheave. A rocking shaft 43, Fig. 2, operates the semaphore and bell rods 51, 57, and carries a weighted cam 46. A lever 45 is also mounted upon the shaft 43. The weight 46 is held in its upper position, as shown in Fig. 2, by one or other of a pair of counterbalanced pawls 47, 48. The signal is then in the 'safety' position. The pawls 47, 48, have downwardly-projecting pieces which engage projections 50, Fig. 17, attached to the barrel formed integral with the sbeave 34. Ropes 25, 33, from the treadle devices 1, 1<a>, Fig. 1, pass round the sheaves 28, 34 respectively, and are thence led over suitable pulleys to counterweights 31, 37. When either of the ropes 25, 33 are pulled by the treadle apparatus, one of the projections 50, Fig. 17, disengages the pawl 47 or 48 from the weight 46, whereupon the semaphore is raised and the bell rung, thereby giving warning of the approach of a train. As the train passes the treadle apparatus 80, the rope 90, Fig. 2, is pulled. This moves a frame 92 to the left against the action of a spring 97. A projection 95 engages the lever 45 and the weight 46 is raised, the signal thereby being set to the 'safety' position. The bell is operated as follows : The rod 57, Fig. 6, slides through a rack frame 58 and has threaded upon it a series of weights 59. The rack frame has teeth 61, which operate a suitable train of wheels driving a toothed wheel 75, adapted to engage a detent 76 projecting from the hammer 77, which thereby sounds an alarm upon the bell 78. The frame 58 and the weights 59 are normally held raised by a collar 79 on the rod 57. When this rod is lowered, the rack frame falls by gravity and sounds the bell. When the rod is again raised, the rack frame is reset, the wheel train being provided with a suitable free-wheel mechanism.