Positions 1, 3 and 4 are isolated from position
2 by the means of a lock over the vertical axis of the
switch actuator. The actuator has to be pushed in to
unlock (approx. 4.5mm, maximum travel 6mm), only
then positions 1, 3 and 4 can be selected. This locking
feature is spring loaded - the switch actuator returns
to locked position when released by the operator
and the current switch position is 2.
Position 1 is spring loaded to return to position 2 when selected and the switch is released. The spring return position can be held in place by a holding solenoid, until the power to the solenoid is cut and the switch returns to position 2.
Those features completely replicate the behaviour of the Boeing 737 engine start switches.
For complete technical specification and usage guidance please download the product datasheet.