Inspection head

摘要

An inspection head to test objects such as plastic bottles for absence of leaks and crushing resistance includes a column having a seal for an aperture in the object which may be applied to the object to exert a crushing force and a fluid supply source to apply a pressure inside the object, which pressure is compared with a reference pressure by means of a movable diaphragm. When the object has an adequate resistance to crushing so that the column does not move beyond a certain point, and the object is free from leaks so that the difference in pressure does not exceed a given value, apertures in sliding members movable according to the positions of the diaphragm and column are in alignment, which fact may be checked by passing a light beam through the apertures. When the apertures are not in alignment the object may be rejected. The head may be used for continuous in-line inspection of objects which are produced successively.