US 3,937,427 A · Cab signal control circuits for railroad interlockings

Abstract

In a railroad interlocking, a cab signal transmitter is coupled to the rails at each exit location and at such other locations as are necessary to supply continuous cab signal energy to trains traversing any possible route through the interlocking. Where train shunts prevent the reception of cab signal energy, wire loops laid adjacent the rails carry the cab signal energy for train pickup. Each rail coupled transmitter is finally activated to supply energy when a train occupies an associated track section. However, the control circuit network for each transmitter also checks, as pertinent for the established route, that a route has been established and the approaching train authorized to traverse that route, that any succeeding track sections along the route are unoccupied, that the transmitter for a preceding section has been activated, and that transmitters for opposing or conflicting routes are not active. A loop transmitter is activated if the corresponding track stretch is included in the established route, the preceding transmitter is active, and the succeeding section is unoccupied. Thus, a train which overruns an entry signal receives no cab signal energy since neither a route nor train authority has been established. For similar reasons, a train which inadvertently enters a conflicting route receives no cab signal energy intended for the authorized train. Finally, if an insulated joint at the interlocking limits fails, a train waiting outside these limits cannot receive cab signal energy intended for a train traversing an established route.

Claims10

Dependent claims

A cab signal control arrangement for railroad interlockings comprising in combination,

a. an interlocking control system connected for establishing routes and authorizing train movements through said interlocking,
b. occupancy detection means connected to rails at selected points for individually detecting the train occupancy of prefixed track sections within said interlocking,
c. a plurality of cab signal transmitters coupled to the rails at selected locations within said interlocking and operable when activated for transmitting cab signal control energy through the rails of an associated track section, and
d. a control circuit means coupled to each cab signal transmitter and controlled by said interlocking control control system, by said occupancy detection means, and by other cab signal transmitter control means for selectively activating the associated transmitter only when a train is authorized to traverse an established route, any remaining advance section of the route is unoccupied, any preceding transmitters along the route have been activated, and the train has occupied the corresponding section.

1 more element

In a railroad interlocking control system, through which interlocking move trains equipped with cab signal control apparatus, the combination comprising,

a. a cab signal energy transmitter coupled to the rails at the exit end of each possible route through said interlocking for supplying cab signal control energy to a train traversing the route toward the exit end,
b. each route including one or more train detector sections,
c. other cab signal transmitters coupled to rails of selected stretches within the interlocking layout for also supplying cab signal energy to trains traversing established routes,
d. an actuating means for each cab signal transmitter coupled to activate the associated transmitter when energized,
e. a separate energizing circuit for each transmitter actuating means jointly controlled by said interlocking control system, said train detection sections, and other transmitter actuating means, for activating the associated transmitter only when a route is established including the associated exit or stretch of track, a train occupies the associated detection sections of that route in sequence, and other transmitters associated with conflicting routes are not activated.

2 more elements

A cab signal control arrangement, for use with a railroad interlocking control system operable for establishing selected routes including one or more detector track sections through a railroad interlocking, comprising in combination,

a. a cab signal energy transmitter coupled to the rails at each exit point of said interlocking for supplying cab signal energy through said rails when activated at selected times,
b. a multi-circuit control network for each transmitter coupled for selectively activating the associated transmitter and including,
1. at least one contact closed when an interlocking route is established with its exit at the associated transmitter rail couplings,
2. a contact closed when the opposite direction transmitter is not activated,
3. a contact closed when the track section including the associated exit end is occupied by a train, and
4. one or more contacts responsive to train detection in other track sections included in the established route,
c. a circuit path coupled for activating the associated transmitter being completed only when a train authorized to traverse the established route and having occupied any preceding sections occupies the section including the associated exit end.

4 more elements

Dependencies are inferred from the claim text.

Cab signal control circuits for railroad interlockings

Life of this patent

Cab signal control circuits for railroad interlockings

Life of this patent

Abstract

Claims10