Patent GB-190519999-A (GB)
Title: Improvements in Signalling Apparatus specially adapted for use on Railways.
Filed: 1905-10-03
Granted: 1906-10-03
Abstract: 19,999. Lake, H. H., [Hall Signal Co.]. Oct. 3. Signalling-systems; semaphore signals; controlling signals.-Semaphore signals are operated by an electric motor through a roller on a spur-wheel lifting a cam-piece on the thrust-rod, with which it is engaged by an electro-magnetic clutch which serves also to lock the signal. The electro-magnet of the clutch is stationary. When the signal is operated, the motor current is cut off by a rocking switch operated by a cam-roller. An automatic electric system is described in which the apparatus is used. Fig. 2 is an elevation of the signal apparatus for operating the 'home' signal thrust-rod 16 and 'distant' signal thrust-rod 17. The motor 6 through toothed wheels drives the wheel 10, which carries rollers 37, 51 to engage cam-pieces 20, 21 sliding on the thrust-rods 16, 17. Fig. 5 shows the details of the clutch. The roller 37 engages the projection 36 on the piece 20, to which is pivoted a spring-pressed dog 22 to catch the tooth 29 of a latch 27 which is pivoted to the thrust-rod 16 and carries on its lower end a roller 30, which bears against the counterweighted lever 35 when that is pulled inwards by the electromagnet 38; thus the thrust rod 16 is lifted. When it is at the top of its stroke, a tooth 32, mounted on the same shaft as the lever 35, engages a spring- pressed dog 31 on the thrust-rod 16 and so long as the magnet 38 is energized holds the rod in its upper position. When this magnet is de-energized, the lever 35 is swung clear of the roller 30, removing the tooth 32 and allowing the thrust-rod to fall. Should the magnet become de-energized while the rod is resting on the latch 27, the rod would then bear on the tooth 29 of the latch 27, which would swing clear of the dog 22 and allow the thrust-rod to fall. As the thrust-rod 16 approaches its upper position, a roller 50 engages the L-lever 43 and moves it to operate a rod 42, connected to the rocking-arm of a switch which makes and breaks circuits at contacts 46, 47, 48 as described later. Dash-pots 18, 19 are fitted, in which the thrust-rods slide. The thrust-rod 17 is operated by similar means from the roller 51 on the wheel 10, but the corresponding switch has only one contact 60. The electro-magnets 38, 54 also control contacts 41, 61. Fig. 9 is a diagram of the system described, although the apparatus may be used in many other systems. Normally, the signals are at 'safety' and the rail circuits closed, the coil 64 being energized, thus completing the circuit through the coil 38 from the battery 66. A train entering the block 62 de-energizes the magnet 64 and opens the contact 67 and thereby the contact 41, thus allowing the 'home' signal thrust-rod to fall, to bring the signal to 'danger' and to open the contacts 46, 47 and close the contacts 48. As the train clears the section 62, the magnet 64 is energized, closing the circuit to the magnet 38, which in turn closes the motor circuit through the contacts 41, 43. The 'discant' signal 15 is controlled from the magnet 65, which is de-energized by a train on the section 63 and opans contacts 77, which together with contacts 79, 46 are in the circuit of the magnet 54, which controls the contact 61 of the motor circuit for the 'distant' signal 15, which is opened at the contact 60 when the signal is operated.