Patent GB-189921561-A (GB)
Title: Automatic Safety Blocking Apparatus for Railways.
Inventor: SACEK JOHANN
Filed: 1899-10-28
Granted: 1900-08-18
Abstract: 21,561. Sacek, J., and Bachmayr, J. J. Oct. 28. Brakes.-Relates to automatic signalling and train-stopping mechanism for preventing railway trains, travelling in the same direction or in opposite directions, from approaching each other within block section limits. Fig. 1 shows the arrangement of the apparatus for a single line. At each block station I, II, &c. are arranged a rubbing contactmaker m and two mercury or other liquid contactmakers g, h, Fig. 4, which are connected, as shown, with the relay f, the batteries i, k, and the needle indicator l, adapted to show line clear' and line ' blocked.' The lead L from the battery i and indicator l is connected to the corresponding lead of the third station in advance. The contacts m are arranged alternately on either side of the central line of the track, and are adapted to make contact with one or other of the brushes d', d<2> on the engine, the brushes being connected up to a battery or other current generator a. The arrangement of the brushes is reversed for trains travelling in opposite directions. The lead from the brush d' is adapted to operate the electromagnet b of a steam whistle, the magnet being also arranged to close the steam regulator and apply the brakes by known means. The contact g, Fig. 4, is operated by the train depressing the rail, which, acting through the plunger t on the diaphragm s, forces the mercury &c. into the chamber u, to connect the insulated contacts 1, 2. The contact h has three chambers u, the central chamber being filled with mercury &c., which connects the contacts 3, 4. In this case, the depression of the rail causes the air in the first chamber to force the liquid in the second chamber partly into the third chamber, so breaking the contact. When a train passes over the contact g in the direction of the arrow, the circuit of the battery k is closed through the relay f, the needle n of which is moved to the contacts q, r. The needle is held in this position by a local circuit from the battery i, until the brush d<2> passes over the contact m at the station IV, on which a current from the battery a passes in the reverse direction through the indicator l and the electromagnet f, and restores the apparatus to its normal or ' line clear ' condition. If, while the relay is closed, another train approaches the station I or IV, its brush d<1> in making contact with m closes a circuit through the electromagnet b, which then actuates the whistle and the stopping-mechanism. If the second train approaches the station IV, the first train also will be stopped at the station III, owing to the previous operation of the apparatus at the station VI by the second train. The apparatus at the station I also serves to release the blocking-mechanism set by a train passing the station IV in the opposite direction to the arrow. In this case, the contact h is first operated, and breaks the connecting-circuit, so that the operation of the contact g produces no effect. The arrangement of apparatus for double lines, for which the contacts g, h may be replaced by insulated lengths of rail, is also described.