GB757851A - Improvements in and relating to the generation of electrical impulses corresponding to apertures in a punched card - Google Patents

Abstract

757,851. Photo-electric record sensing. MITHRA, AKT.-GES. Aug. 19, 1954 [June 23, 1954], No. 24173/54. Class 40 (3). A device for generating electrical impulses representative of information on a punched card comprises a rotatable hollow cylinder on the surface of which is clamped a conventional punched card 136 the cylinder being provided with apertures corresponding to the possible positions of holes on the card, a light source inside the cylinder and photo-electric converters outside so arranged that each receives light from one of the apertures arranged along a generator of the cylinder through a separate light passage. As shown, the cylinder 121 on which the card 136 is arranged has end-pieces 122, 123 which overlap the edges of the card and hold it in place. A pair of pins on the cylinder co-operate with special holes in the card to assist in locating the card. Endpieces 122 carry flanges which co-operate with similar flanges on a driving member 110 to enable the cylinder to be coupled to or withdrawn from the member. The cylinder is positioned so that its flanges enter the spaces between those on member 110 and is then rotated so that its flanges engage behind those on the member. Member 110 is attached to a ring 107 which rotates on ball and roller bearings 105, 106 on a central hub 104. The outside of the ring 107 carries teeth 108 which enable both the ring and, through the coupling, cylinder 121 to be rotated. Spring-loaded balls 130 mounted in ring 107 press against the flanges of cylinder 121 maintaining those flanges in engagement with those on driving ring 110. The internal surface of cylinder 121 has longitudinal slots; the outside surface circumferential. These slots are of such depth that they intersect forming apertures corresponding to those on the card. Fixed central hub 104 on which bearings 105, 106 are mounted carries fixed cylinder 113 having a single slot 119 along its generator. Inside the fixed cylinder are lamps 114. Alternatively, a single tubular lamp may be used. Connections to the lamps are brought through the central hollow hub as also is a supply of cooling air for the lamps. Reflectors 118 are mounted one at each side of the row of lamps. Above the surface of the rotating cylinder is a block 146 consisting of a number of sections 147 bolted together. Above the sections is block 148 of resilient material for example sponge rubber in which are mounted in suitable recesses twelve photo-electric cells in three rows of four each (Fig. 2). Each cell is associated with an aperture 150 in block 148 so as to receive light from one of the twelve possible positions along a generator of cylinder 121. Thus as the cylinder rotates all possible positions for apertures in the card are examined.