Specifications

RailCorp Infrastructure Engineering Manual – Signalling

Maintenance Manual

Electric Point Machine Westinghouse Style M70 MKIII TMG E1583

4.3 Points Throw and Lock Mechanism

4.3.1 Description

The points throw and lock mechanism, Figure 4.3.1, consists of the slide bar, the throw

bar, the main crank, the lock box and lock slides. The main crank, driven by the gear

train, operates the throw and slide bars to throw and lock the points. The position of

the switch points is checked and secured by the lock box, which rests on and is

operated by an extension of the slide bar. The lock box and lock slides are so

arranged that the point machine may be installed on the right or left of the points

without internal changes to the machine.

4.3.2 Adjustment of Lock Slides

Adjustment should be conducted under manual operation (Section 4.e).

1. Throw points to close switch adjacent to the point machine.

2. Loosen clamp bolts.

3. Adjust rod connection so that locking dog in lock box engages notch in lock slide

and in doing so, holds point blade against stock rail.

4. Wind the points to close the opposite switch.

5. Move the second lock slide into correct position so that the other locking dog in

the lock box engages notch in lock slide. Engage serrations and tighten bolts

clamping slides together at each end.

6. Test adjustments in the following manner:

(a) Insert a 1.6mm (1/16") gauge between the point of the switch and stock rail.

The lock should be adjusted such that locking is completed.

(b) Insert a 3.2mm (1/8") gauge between the point of the switch and the stock

rail. The lock should be adjusted so that locking cannot be completed. Re-

adjust if necessary and repeat step (a).

Note: The locking action may be observed through holes in the casting covering the

lock box. When adjusting the slide with the notch on the bottom, marks made on top

edge are used as a guide.

Issue Date: 1 December 2009 Uncontrolled when Printed