Patent GB-190714518-A (GB)
Title: Improvements in or relating to Signalling or Alarm Apparatus for Railways.
Inventor: BOULT ALFRED JULIUS
Filed: 1907-06-24
Granted: 1908-06-24
Abstract: 14,518. Boult, A. J., [Zorge Safety Railway Equipment Co.]. June 24. Detonator apparatus; semaphore signals; signalling-systems ; fog signals. - An apparatus for warning the driver of a locomotive of his approach to an open switch point comprises a rotary detonator carrier and an ejector, controlled by electric track circuits and driven by a motor, the ejector being weightoperated. Fig. 1 shows the track circuits and connexions to the detonator mechanism, Fig. 2 is a section of this mechanism, Fig. 5 shows the rotary carrier, and Figs. 9 and 10 show details of the detonator mechanism. The r o t a r y carrier b<7>, Figs. 2 and 5, comprises a disk having projecting arms b<57> provided with guides b<58> on their upper surface to receive the detonator or holder b<10>, and on their lower surfaces with slots b<59> and radial flanges connected by curved portions, thus affording cam-surfaces for engagement with the crank b<40> which serves to actuate the carrier. Each slide b<10> has an inner depending lug b<62> for engagement with the ejector-member b<14> ; these lugs lie normally within the ring b<53> which has an opening opposite the slot b<56> in the disk b<5> to allow of the detonators being placed on the rail. The outer ends of the holders have lateral lugs b<63> normally resting on flanges b<64>, and when a detonator is ejected with its slide, the lugs ride off the flanges and allow the holder to fall slightly so that the flanges b<64> will be in position to prevent the complete return of the holder unless its detonator has been exploded and the lugs b<63> shattered. The detonators b<65>, with their holders, are ejected by a weightactuated rock arm b<14> made up of two telescopic sections, Fig. 9, one loosely mounted on the rockshaft b<15>, Figs. 2 and 9, and actuated through projections b<67>, b<68> of the member b<16> rigidly connected to the shaft b<15>, and the other pivotally connected to the slide b<70> supported on the guide b<71>. The working of the apparatus is as follows. A train approaching the open points A<5>, Fig. 1, de-energizes the magnet 16, thus breaking the circuits B', de-energizing the magnets b<44>, b<45>, Fig. 2, which are in parallel in the circuit 12, and allowing the semaphore 7 to fall to 4, 8, and 12, 'danger.' The armature rod b<18> of the magnet b<45> is thus released and the weight b<41> allowed to actuate the ejector-arm b<14> to project a detonator into position over the rail ; at the same time, the switch b<43>, which is the armature of the magnet b<44>, is moved by a weight to complete the motor circuit through a disk b<42>. The motor b<26> actuated the gear-segment b<20> through a gear-train and causes the eccentrically fixed magnet b<45> to slide upon its armature rod b<18>. The disk b<42> is also turned until the switch b<43> makes contact with an insulation block thereon, thus breaking the motor circuit. Immediately before the circuit is broken, a cam on the gear b<20> causes a shunt circuit to be completed, so that the motor stops as soon as its current is cut off ; this occurs when the gear b<20> has made one-third of a revolution and the magnet b<45> has been brought into re-engagement with its armature, and is locked thereto by the pawl b<81>, Fig. 10. When the switch-point A<5> is shifted, the circuits B<1>, B<2> are closed, thus re-establishing the circuits 4, 8, and 12 and re-energizing the magnets b<44>, b<45>. The switch b<43> is thereby moved to complete the motor circuit again. The disk b<42> is then turned as before until its second insulation block makes contact with the switch ; previous to this the shunt circuit has been completed. The magnet b<45> and its armature are also returned to their normal positions when a pin b<83> attached to the frame acts on the pawl b<81> to unlock the armature ; if a detonator has been exploded, the arm b<14> makes a complete return, in which case the arm b<72> of the slide b<70> strikes the rod b<38> and throws the clutch member b<34> into engagement with the members b<33>. At the same time, the movement of the mutilated gear b<20> first causes the pin b<94> to engage the projection b<93> of the locking-member b<88> to unlock the gear-wheel b<29> which is then turned by the meshing of the gears b<20>, b<29>, the movement being assisted by a pin b<84> striking one of the projections b<85> on the cam b<86>. The movement of the gear b<29> is communicated through the clutch members b<33>, b<34>, by means of bevel-gearing, to the crank b<40>, which thereupon turns the carrier one step to place a fresh detonator in position to be ejected. If the first detonator is not exploded on the retraction of its holder, the movement of retraction is rendered incomplete by the engagement of the lugs b<63> and the flanges b<64>, the rock-shaft h<15> being permitted by a spring to make an idle movement, while the gear-wheel. b<20> completes its movement. The clutch member b<34> is therefore not brought into engagement by the rod b<35>. A train passing over the track in the reverse direction breaks the circuit B <5> before breaking the circuit B<4>. The armature 25 therefore falls back and locks the armature 17 in position, its pin 19 engaging with the top of the armature 25, so that the circuit B<3> cannot be broken by the short circuiting of the circuit B<4>. The whole of the detonator placing mechanism is fitted in the box B, having a hinged lid, the driving- mechanism being supported on the hinged plate b<5> and bearing-plates attached thereto, the electric connexions being taken through two angled terminals, as shown in Fig. 2, to allow of the swing- ing-out of the mechanism for inspection when the rotary carrier has first been removed. The shanks of the detonators are weakened by perforations so that the shank may be readily broken by the explosion.