Patent GB-419149-A (GB)
Title: Improvements in track-actuated train control apparatus
IPC: B61L3/10
Filed: 1933-05-03
Abstract: 419,149. Track apparatus for train control. HASLER AKT.-GES. VORM. TELEGRAPHEN-WERKSTATTE VON G. HASLER, Berne, Switzerland. May 3, 1933, No. 12938. Convention date, May 3, 1932. [Class 105.] A train passing over an electrified ramp at a control point, such as at a signal, or at the approach to a level crossing to a sharp gradient or curve, or to a gang working on the line, where the driver must be alert, has a polarized brake-actuating relay operated to release a brake valve unless an attention switch is manually operated such attention switch however not being effective with a signal at danger. Figs. 1 and 2 show an arrangement in which track batteries are used; ramps Ku at various fixed warning locations are permanently connected to the positive side of the battery Sb while the ramps Ka at the signals are positively or negatively energized accordingly as the signal is at clear or danger. With positive battery applied over the engine contact to the lead 6 and with the attention switch Wo-Js operated to open a contact 15, the winding 7 of the relay BA is energized by an upward flow current and so maintains the rod 9 closing the brake valve Bv ; if the attention switch Wo-Js is not operated then winding 8 is also energized but by a downward flow current so that the rod 9 drops and opens the braking valve Bv. Fig. 15 shows the arrangement for the control of the rod 9 by the polarized relays 7, 8. With a signal at danger negative battery is applied to the lead 6 so that the winding 7 is reversely energized and, whether or not the attention switch is operated to cut out or leave in the winding 8, the rod 9 drops to open the brake valve Bv. Figs. 3 and 4 show an arrangement in which only a locomotive battery Fb is used. At fixed warning locations ramps Ku are connected to the rails while at signals there is one ramp Kal permanently connected to the rails and a second laterally spaced ramp Ka<11> so connected if the signal is at danger. At a fixed warning location and the attention switch not being operated the winding 8 is energized from + Fb over Hz in the dotted position, 17, 18, the rails Fs, the ramp Ku, the engine contact, the lead 6, and the non-operated attention switch arm Js on contact 15. The winding 8 is energized by a downward flow current and so the rod 9 drops to open the brake valve Bv. If the attention switch Wo-Js is operated the above circuit is opened at contact 15 and so the rod 9 is not dropped. The same actions occur at a clear signal but at a danger signal a parallel energizing circuit for the winding 8 is completed over the second ramp Ka<11> a corresponding second engine contact, and lead 19, so that the operation of the attention switch Wo-Js to open the contact 15 will not now prevent downward energization of the winding 8 and therefore the rod 9 drops to open the brake valve. The contact arm Hz is operated by the brake air or steam pressure to ensure the apparatus being put into readiness when starting up ; the contact 20 on being swept over gives a test braking. A dual arrangement, Fig. 5 (not shown) is described combining the above two arrangements. The switches 5 connect the engine contacts for forward or reverse running. A recording strip is marked by pins Bk, Wk, Jk when the brake control rod drops, when the attention switch is operated, and when the ramp current pulse is received with the driver alert. To prevent the driver permanently maintaining contact 15 of the attention switch open a device such as shown in Fig. 7 is provided wherein a handle 22, provided with a spring locking catch 23<1>, actuates by means of a pawl 28, tripped by an abutment 32 after 60‹ movement, a spring-returned disc 30 which drives a toothed wheel 36 by a pawl 33 engaging a disc 31. The 60‹ movement of the wheel 36 causes a smaller wheel 37 to make one rotation and so to tilt and return a mercury switch device 40 which has a slow return flow through a capillary 43 during which time the contact 6-15 is open permitting the prevention of the braking. Another such device, Figs. 8-14 (not shown), comprises a push which is only operative when a distance piece is located in front of a switch operating rod.. On operating the push this distance piece is moved away from a stop which prevents radial inward movement whereupon the distance piece is moved by a spring out of the operating position and can only be returned thereto by a 180‹ rotation of the cover disc in which the push is mounted.