device for beruehrungslosen laengenmessung a luminous object

摘要

913,049. Photo-electric gauging. GENERAL ELECTRIC CO. April 20, 1960 [May 4, 1959], No. 14007/60. Class 40 (3). A gauging device for measuring the dimension of an object comprises a scanning head including a rotatable member with a plurality of equi-spaced portholes disposed in a line around its periphery and a plurality of counter marks formed adjacent each porthole for providing an indication of the dimension of an object viewed through the portholes. The scanning head 11, Figs. 4, 5, is formed by a drum member having eight portholes 13 each provided with a lens 16 and effectively traversing a length indicated by A, B, C, Fig. 1, spanning or including the object 12 which may be a white-hot slab of steel and from which light is passed to a photo-transistor 17 mounted near the axis 21 of the drum. The plane end-surface 22 of the drum is provided with eight circularly arranged and equally spaced holes 23 which allow light to pass from sources 27, 28, 29 to photo transistors 24, 25, 26 disposed within the drum and positioned so that they are actuated in succession as the lines 13a, 13b, 13c from the axis of the drum through the centre of a porthole 13, are directed to the points A, B, C respectively on the member carrying the object 12. Screens 33 provided with counter marks disposed axially of the line of portholes 13 and lying between each pair of portholes are associated with a light source 37 anda photo-transistor 36. The marks are arranged on the screens 36 to allow for the non-linearity of the scan and for different thicknesses of the objects 12, and the scanning head 36, 37 can be moved axially of the drum by a shaft 38 actuated by a servomotor to allow for different conditions. Pulses from the transistors 24, 25, 26 control an " inzone " detector 41, Fig. 7, passing a pulse to a read-out gate 42 providing an input to an " AND " gate 77. A pulse from the photo transistor 17 corresponding to the length of the object 12 provides a second input to the gate 77 so that pulses from the photo transistor 36 associated with the marker screen can pass to a binary counter 89 and thence to a circuit 123 for conversion to a decimal basis, and display on a screen device 124. The added result of eight determinations is displayed and this total may, if desired, be divided automatically to indicate the measured length of the object 12. Each pulse from the detector 41 in response to a pulse from the transistor 26 effects illumination of the display device 124, and after eight of these pulses the counter 89 is reset to zero.