22
Operation
Steering
Directional control of the pedestal is achieved by turning the steering
ring mounted at the top of the column. The steering system is geared
so that the skid wheels turn by the same amount as the steering
ring. This ensures, for example, that with the pedestal set to crab,
turning the steering ring by 90° will also cause the pedestal to change
direction by 90°. The steering ring is fitted with two movable indicators
(4) which can be used to mark the straight-ahead position of the ring
and will provide a reference point when steering.
The skid has a crab/steer arrangement with a foot-operated
changeover mechanism, which provides a steer setting i.e. one wheel
steering, two fixed; or a crab setting, where all three wheels turn
together.
Movable indicators
Pushing the foot-button (16) operates a changeover mechanism
which toggles the pedestal between crab and steer. The button can
be pressed with the wheels in any position, but the changeover will
not occur until the wheels are all facing forward, so the steering
ring may have to be turned by up to 180° before the changeover
mechanism engages. This arrangement ensures that the rear wheels
will always lock in the straight-ahead position when changing from
crab to steer.
A clutch in each wheel unit disconnects that wheel from the steering
in the event of the wheel striking an obstacle. To reconnect the wheel,
hold the steering ring stationary and turn the wheel unit until the clutch
re-engages.
!
WARNING
!
To ensure maximum stability, particularly
when moving over uneven ground, reduce pedestal
height to a minimum.
Position 1 for one wheel steering with two fixed wheels.
Position 3 for Crab steer, all three wheels turn together.
