Apparatus for Operating Railway Signals, Train Stops, Train Brakes and Crossing Gates.

摘要

24,261. Johnson, A. H. Nov. 12. Brakes-Relates to means for operating railway signals, train brakes, &c. and consists in improvements in connexion with the apparatus described in Specification No. 11,005, A.D. 1905, [Abridgment Class Railway signals &c.]. The signals &c. are operated from an electric motor m in a casing j, which motor drives a Roots' blower or similar type of rotary pump enclosed in an inner casing r, to pump oil, which fills the casing to the level h-h past the non-return valve d1 into a chamber V1. The oil passes through the duct f to the cylinder c, thus lifting the piston p, to which is attached the operating-rod p1 for the signal &c. to be moved. A partly balanced gate-valve V pivoted at z is held closed by the armature n of an electro-magnet o in parallel with the motor, but, when the motor circuit is broken at the main switch, the valve is opened by the pressure of oil under the piston p, which is thus allowed to drop quickly. The motor circuit is alone broken, however, when the switch s is opened on the completion of the necessary movement of the operating-rod p1, at which time a pawl t mounted on a pivoted lever y, which normally holds the contact s' up to close the circuit, is forced over by the spring w1 acting on the roller w to open the switch quickly, the movement being allowed by the driver u, which normally holds the switch closed, moving above the pawl. On the return of the member p1 after the motor circuit is broken, the pawl is first forced out by the lower end of the driver u without moving the lever y, as shown in Fig. 4 ; but, as soon as the corner formed by surfaces t1, t11 is passed, the spring quickly snaps the pawl up to its normal position and closes the switch s. To prevent the signal &c. from sticking in its operated position, a constant leakage is allowed past the piston p, or a leak port is provided therein, whereby a constant movement is given to the member p1, which first drops with leakage until the switch s is closed, whereupon the motor m pumps more oil until the switch again opens. Should the valve V fail to open when the main switch is opened, this leakage allows a gradual return of the operated member. To prevent the raising of the piston by means, other than by pressure of oil, a detent x is pivoted to the rod p1 and normally engages in a recess x1 in the casing, from which recess it is moved by air pressure on the plug x11. Instead of the piston, a diaphragm, ram, or equivalent device may be used, and the action may be radial instead of straight, while the pawl t may be mounted on a slide. To operate a home and a distant signal from one motor, the rod of the home arm is operated as before, thus opening the port l, Fig. 7, to raise the distant signal rod, the motor being cut out when this has risen and the two signals are at safety. The distant signal has a port b1 leading to a separate controlling-valve to allow the signal to be returned when necessary.