Patent GB-941222-A (GB)
Title: Data processing equipment
Inventor: TURNER FREDERICK JAMES LESLIE
IPC: H04L17/08
Filed: 1961-11-03
Abstract: 941,222. Selective punching machines. CREED & CO. Ltd. Nov. 3, 1961, No. 39460/61. Heading B4B. In data processing equipment, characters are punched in a tape and each character is read and compared with a character with which it should be in accord, and in the event of disagreement between compared characters punching of characters ceases and the tape is advanced to a position at which the compared character in the tape is erased by overpunching the tape at that position, after which overpunching the punching, reading and comparing functions of the equipment continue. As shown in Fig. 1, characters are punched in a tape T by means of apparatus P and the elements of a punched character are read by photo-electric means R which is connected to a comparator C in turn connected to a control unit CU which responds to electric current signals from the comparator to control the operation of the apparatus P and also of perforating apparatus PA. The apparatus PA, Fig. 2, which is described in Specification 941,223 comprises a die-plate 1 and a stripper plate 2 between which the tape is fed, the plates incorporating holes H and FH arranged in four rows and nine columns. Corresponding to the holes are punches 5 and guide pins 17, Fig. 3, which are reciprocable vertically relative to the die-plate by means of operating bars 8 secured to carriers 9 coupled to a rod 10 which engages in a cam track 11 of a cam plate 12 secured to a rod 13 which is coupled to an operating lever 14 in turn coupled to a solenoid armature SA. The punches have slots S, Figs. 3 and 4, the upper ends of which are engageable by the upper sides of tapered operating bars 8, the arrangement being such that when the bars are moved downwardly, the pins 17 of the rows first engage in the feed holes FH in the tape after which the punches in columns C1 to C8 are engaged successively to effect columnwise perforation of the tape. In operation, the tape is fed in the direction F, Fig. 1, and punched in successive character positions by apparatus P. The elements of successive perforated characters are sensed by the means R. Signals indicative of the condition of elements of a previously-perforated character are applied to the comparator C where they are compared with those of the character intended to occupy that character position. In the event of an error being detected, a signal is generated and applied to the unit CU by the comparator. The unit CU likewise generates signals which are fed to the operating mechanism associated with the apparatus P. As a result, the apparatus P ceases, temporarily, to perforate the tape and feeds blank tape. When the element positions of the character in which the error has been detected and the character last perforated are beneath the punches 5 of the rows of punches R1 and R4, a signal is applied to a solenoid associated with armature SA. In consequence, the lever 14 is pivoted in directions B and C, Fig. 2. In its pivoting movement in direction B, it causes the guide pins 17 to engage feed holes FH in the tape and the punches 5 of rows R1 to R4 to overpunch the elements of the last four characters perforated by the apparatus P. After the overpunching operation, the apparatus P, which has meanwhile been set to punch correctly, perforates the elements of the four characters in succeeding character positions on the tape.