Patent GB-190408064-A (GB)
Title: Improvements in or relating to the Working of Single Lines of Railway on the Electric Staff or Other Electric Systems.
Inventor: JACOBS CHARLES MARK
Filed: 1904-04-07
Granted: 1905-03-02
Abstract: 8064. Jacobs, C. M. April 7. Controlling traffic on railways, staff and ticket systems for. - A special " occupation " instrument is described for use in a system allowing occupation of sections by trolleys for repairing and other operations on single lines worked on the electric staff, tablet, or other electrical system, such as the electric locking-system. A portable occupation key d, Fig. 3, fits into a disc and a cylindrical commutator a, which it can turn into three positions indicated by notches p, q, r in the disc to set up different conditions of circuit. The key can only be withdrawn when in the position r. A projection f on the commutator engages with a catch g attached to the armature c of an electromagnet b, and prevents further rotation of the commutator than from the position p to the position q, unless the magnet b is energized and raises the catch g. The magnet consists of two coils b<1>, b', the cores of which form a closed magnetic circuit with poles i, i<1> for the armature c. Fig. 1 shows diagrammatically a system employing two such instruments k, k<1> between two staff instruments, the line-wire j being looped into each occupation instrument, and a special line-wire l passing from earthed batteries n at each occupation instrument to an electromagnetic switch o, which retains the staff instrument circuit closed in the position shown when the occupation instrument discs are in the positions p, r, respectively. If now the commutator of the instrument k is turned to the position q, and two positive or two negative currents are sent from the staff instruments S, S<1> (only possible when all the staffs are in the instruments S, S<1>), the electromagnet of the instrument k is energized, and the catch g withdrawn, allowing an occupation key to be withdrawn by turning the armature and disc of the instrument k to the position r. The circuit through the switch o is then broken, and the communication between the staff instruments S, S' broken thereby. Only one occupation key is of course used, and this must be in either occupation instrument before a staff may be withdrawn at either end. Indicators may be employed at the occupation instruments and at the staff instruments to show when the lock is withdrawn from the occupation instrument, a d when the occupation key is in an instrument. Telephones or indicators are employed for ordinary communication between staff and occupation instruments. Similarly, several occupation keys may be employed in one section with two or more instruments for each key with similar precautions and arrangements as above. A special line-wire is employed with each set of instruments, and includes an electromagnetic switch at a staff instrument. In a further modification, a key is provided for each occupation instrument, and only one key may be used at once in a section. Here the special linewire and electromagnetic switch are dispensed with, and the staff instrument line-wire looped into each occupation instrument is broken whenever a key is withdrawn. In a further modification employing several sets of instruments, each set with a special line-wire as before, keys are provided for each instrument with only one battery for each set.