Patent GB-764655-A (GB)
Title: Improvements in or relating to record card controlled printing mechanisms
Inventor: ASH DENIS JOHN
Filed: 1955-02-14
Abstract: 764,655. Record-card controlled printing mechanism. BRITISH TABULATING MACHINE CO., Ltd. Feb. 14, 1955, No. 4295/55. Class 100(4) A printing mechanism has a type wheel (not shown) mounted on a plate which may be swung towards a platen to effect printing of the selected character in a manner similar to that described in Specification 704,764. It is positioned under joint control of a digit selection means and a zone selection means to select a character for printing, the digit and zone selection means being operated in response to differentially timed digit and zone impulses derived from the sensing of a record card and has means operated by the occurrence of one of digit impulses in conjunction with any preceding digit impulse, and means also for providing a further zone impulse at a different time to the card impulse times when said digit impulse means is operated. Type characters may be arranged on the type wheel in groups, one character of each group being selected in response to a digit impulse, two or more being selected in response to a digit and a zone impulse together and a further character selected in response to a digit impulse together with a special zoning impulse which occurs if the latter digit impulse precedes and occurs in conjunction with a chosen one of the digit impulses. In the apparatus shown, a type wheel with gashes in its periphery, is mounted on a plate 7 and is rotatable by a gear 3 through a gear train which includes gear 70. The cycle of the printing mechanism bay have twenty-five equal intervals in the first nine of which digit impulses 9...11 may be received, and zone impulses may occur in intervals 10...13, thus allowing for a maximum of fourty characters on a card. The digit position 1 in combination with the other digit positions is used to represent an extra group of characters such as fractions. The cards to be sensed are fed by a motor which also drives a shaft 71, Fig. 3, which makes one revolution for each cycle, and drives a gear 50 through a mutilated gear 51 through half a revolution, and after a period of rest, through the other half revolution. Gear 49 integral with gear 50 drives gear 48 fast on shaft 1 and having half number of teeth of gear 49, so that shaft 1 makes two revolutions per cycle, comes to rest during interval 10, Fig. 5 (which is a schematic timing diagram), and starts to revolve again just before end of interval 15. The type wheel is coupled to the shaft 1 for rotation normally in one direction by digit selection means comprising a pawl 13 pivoted on outer face of gear 3 and urged into slot 17 in shaft 1 with an extension 18 of pawl adjacent a stud 12. A zoning sector 19 may be coupled to the type wheel for rotation in the opposite direction, both the digit and zone selection means being controlled by a single operating electromagnet. The gear 3 and a latch plate 5 are mounted concentrically on the shaft 1 and the gear and plate 5 move together when the gear is driving the type wheel in one direction or when the plate 5 is being driven in the opposite direction, the gear being coupled to and uncoupled from the shaft by a digit selection pawl 14 mounted on the zoning section 19 and normally engaged by an operating latch 30 and notches in the latch plate 5. The pawl is released to engage the latch plate by the energization of an operating magnet 73 by a digitimpulse from the sensing of a record card or by movement of the zoning sector 19. A zoning bail 22 may be coupled to thezoning sector 19 to move concentrically to shaft 1 and is uncoupled when the magnet 73 is energized by a zone impulse. An auxiliary zoning plate 37 is attached to zoning sector 19 so as to have limited relative movement and a zone selecting pawl 45 carried by the bail 22 and engageable with one of a number of notches in the zoning sector is disengaged from the notch by the plate 37 if a notch in the plate is engaged by a zone selection pawl. A first electromagnetic relay, which may have means for mechanical latching the contacts of the relay in operative position, is operable by any of the digit impulses except the further zone impulse, and a second electromagnetic relay is operable by the said zone impulse.