Improvements in or relating to article-gauging apparatus

897,420. Photo-electric gauging and sorting apparatus. GENERAL ELECTRIC CO. Ltd. Dec. 3, 1959 [Dec. 3, 1958], No. 39006/58. Class 40(3). An apparatus for gauging in turn at least one dimension of each of a plurality of articles fed to it in sequence includes means for engaging each article in turn and holding it in a predetermined gauging position, at least one pair of mutually spaced receivers, each of which incorporates a photoresponsive device arranged to receive light from an associated one of a pair of mutually spaced light projectors with the projectors and receivers arranged so that only narrow beams of light from the projectors are measured in the direction in which the light beams are spaced apart, are permitted to reach the respective photo-responsive devices, and so that the beams define at the gauging position a pair of boundary positions corresponding to different sides of the part of the article to be gauged, whereby when the article is held in the gauging position the projection of said part beyond a boundary position cuts off the light from the respective photo-responsive device, in combination with a control circuit coupled to both of the photo-responsive devices and giving an output signal which depends on the change of the illumination of one or both of the photoresponsive devices by the projectors in relation to the illumination of the devices at the boundary positions, and directing means responsive to the output of the control circuit and arranged to direct each article from the gauging position to a particular one of two or more reception channels predetermined by the conditioning of the control circuit by the photo-responsive devices whilst the article is in the gauging position. In the arrangement shown, bottles 2 of rectangular shape on reaching a gauging position are automatically clamped by positioning members 3 and a sensing unit 4 is automatically lowered to its operative position. The principal dimensions of the bottle are sensed in each of three planes by an arrangement, shown in Fig. 4, comprising two pairs of projectors 5 including lightsources 7 and associated photo-responsive receiver members 6 incorporating photosensitive cells 13. Provided that the dimension of the bottle is less than a prescribed maximum in each of two directions in the three planes, the beams from the sources 7 can pass to the associated photo-cells, each of which is arranged to produce a signal if the associated light beam is interrupted by an overs