Patent GB-190108883-A (GB)
Title: Improvements in or relating to Electric Signals for Railways
Inventor: NETTER JACQUES AUGUSTE
Filed: 1901-04-30
Granted: 1902-06-30
Abstract: 8883. Netter, J. A., and Queyroul, B. A. April 30. Signals on engines and trains ; indicators and repeaters, signal ; contacts, electric ; accidents, signalling in case of; signalling &c. between trains. -For indicating to the driver and guard when a train passes a 'danger ' signal, the battery x on the engine is connected to earth at z, and also at g<111> through the engine frame &c., the circuit including a resistance r and a fragile conductor g, while a branch y<11> earthed at y<111> includes a bell s on the engine and a second bell s' in the guard's van. The conductor g may consist of a stick of carbon, or a glass tube metal-plated or containing a conducting-liquid, &c., the bell circuit being made of such resistance that the bells are not operated so long as the conductor g is unbroken. The conductor is carried on a pivoted fork, and is normally elevated, as shown, so that, when a 'danger' signal is passed, a rod on the signal breaks the conductor and so causes the bells s, s' to ring. The pivoted fork is lowered automatically to enable it to pass under bridges, tunnels, &c., its operating-rod being actuated by a solenoid h connected to a brush b, which makes contact with the contact-rail B at the entrance to the bridge &c. At the exit from the bridge &c. is a second rail A, which by making contact with the brush a energizes the solenoid g', and restores the fork to its normal position. A locking-catch for the operating-rod is controlled by the solenoid d' in the circuits of the solenoids h, g<1>, either of which may be energized by the driver by means of the switch m, thus enabling him to lower the fork when he sees a ' danger' signal in time &c. When the fork is lowered, the earth connection gill is broken, and the circuit through the conductor g is completed at the contact k<1> through a bell k in the guard's van, this bell ringing until the fork is raised again. The fork can also be turned to the other side of the engine, when the latter is run tender foremost &c., the contacts g<111>, k<1> being duplicated. In order to warn the driver of his approach to a 'danger' signal, the signal, when at ' danger,' may close a contact connected to a contact-rail C, which, on engagement by the brush c, completes the circuit of the bell g<11>. This bell will also ring when the brush c engages any contact connected to earth. The Provisional Specification also describes the following arrangements :-To protect a train stopped or blocked on the line, insulated contacts fixed at suitable distances apart on the line are connected in overlapping groups of three by insulated wires supported on the telegraph poles. To protect the stopped train, the driver or guard connects the proper wire to earth by a flexible wire connected to the locomotive, so that an approaching train passing over the corresponding contacts will receive an alarm. Where great snowfalls are probable, the contacts are replaced by short posts provided with hammers, which are operated by electromagnets connected with the line-wires for breaking the fragile conductors. To form an automatic block system, insulated contact-studs are arranged along the track about seven yards apart, and connected to form block sections, each locomotive having a brush about eight yards long, which connects the studs to earth. The brush may be replaced by a perforated tube discharging jets of vapour or streams of liquid, to make contact with the studs, or the studs may be replaced by a suspended wire earthed by a jet of vapour from the funnel of the locomotive. These contacts may also be replaced by hammers operated by electromagnets for breaking the fragile conductors.