Patent GB-653313-A (GB)
Title: Improvements in or relating to statistical record sensing devices
Inventor: BALDWIN RICHARD EVEREST
Filed: 1947-03-25
Abstract: 653,313. Photo-electric control systems. POWERS-SAMAS ACCOUNTING MACHINES, Ltd. March 25, 1947, No. 25854/49. Divided out of 653,312. [Class 40 (iii)] In a statistical record sensing apparatus in which rows of slots are examined photoelectrically while the record is moving in a direction perpendicular to the rows, a beam of light traversed across row in the line taken by the record to travel one row pitch and is simultaneously advanced a pitch distance in the direction of travel of the card. In the embodiment described in the Complete Specification (Fig. 4, Comp.), each card is ejected in turn from a magazine 20 by a picker 21, and is passed with a long edge leading between rollers 36 where it is sensed and rollers 38 to a magazine 49. The complete system of which the invention forms part is described in Specification 653,312. Sensing mechanism.-Each card passes beneath a plate 57 which has a group of eighteen apertures inclined as shown in the direction of card travel, Fig. 5 (Comp.), for each half of the row, selected apertures being blanked out as desired. Each half of the templet is scanned by the image of the filament of a lamp 51, one only of which can be seen in the Figure, positioned above a rotating disc 58 on which are circumferentially mounted a number of lenses. This lens carrier rotates at such a speed that as the card passes beneath the templet the beam of light passes through each successive perforation on the templet and, if a perforation exists in the card, is passed from reflectors 56 beneath the card to one of a pair of photocells. The lens carrying discs are driven by gearing from the main shaft 30 at such a speed that as the beam from one lens completes its scanning of one row so the beam from the next lens commences to scan the next row. The position of the photo-cell output pulse in the scanning cycle represents the value of the digit scanned and the photo-cell is switched by a cam in the main shaft during the scanning cycle to feed an amplifier. The output of the amplifier is then fed through commutator switches driven by the main shaft to the wipers of contact drums which convert the values of the digit into binary and quinary sub-denominations. The speed of the wipers is such that when a station representing a particular digit value is being sensed the wiper is in engagement with contacts representing the value of the digit in the binary-quinary rotation. In the embodiment described in the Provisional Specification (Fig. 1), a picker similar to that described in the previous embodiment feeds cards singly from a magazine and through rolls 11 narrow edge first and is fed, wide edge first over a sensing mechanism 51 to rolls 18 which feed the card to a punching mechanism and then to a receiver. The sensing mechanism comprises a mirror drum the sides of which are eight trapezium shaped mirrors on to which a beam of light is focused. The mirrors are rotated by a skew shaft 50 driven from the main shaft 63 through skew gearing. The speed of the rotation of the mirrors is such that as each card passes over the drum the reflected beam of light travels across the card and, due to the skew mounting of the mirrors with respect to the direction of card travel of is advanced a distance equal to one pitch. The light passing through the apertures is focused by cylindrical lenses 61 on a photo-cell 60. The outlet of the photo-cell is fed through a D.C. amplifier to distributer drums similar to those described above.