Parts are orientated by tooling, inside or outside of the bowl
feeder. In-bowl tooling tends to be passive and relies on the
probability of a correctly orientated part moving along the conveyor
track. Incorrectly orientated parts are detected by the bowl
tooling and deflected back to the bowl base. Correctly orientated
parts are accepted by the tooling and presented to the workhead.
Active tooling accepts parts in more than one orientation and
re-orientates them correctly for the workhead. This method of
tooling gives a 100% 'first time through' rate and can be used outside
the bowl.
It's important to make parts as symmetrical as possible. Higher
feed rates are obtained with parts having greater degrees of
symmetry. This is achieved by duplicating non-productive
features. If it is not feasible to make a part symmetrical then
it must be designed to be definitely asymmetrical. Features which
are too small to be detected by bowl tooling must be exaggerated, for
them to be detected. The use of cylinders having a length to
diameter ratio of unity and rectangles having slightly dis-similar
sides should be redesigned to give greater asymmetry.
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