Patent GB-247988-A (GB)
Title: Improvements in and relating to automatic printing machines
Filed: 1926-02-19
Abstract: 247,988. Hilditch, E., and Str÷m, U., (Representatives of Bull, F. R.). Feb. 20, 1925, [Convention date]. Statistical machines; printing totals. - In selective printing mechanism controlled by a perforated strip or cards and comprising typewheels mounted on a shaft rotating synchronously with a device for feeding the cards or strip past contacts, the type-wheels are arrested momentarily when impression is effected. The typewheels may be controlled for printing the total of a series of statements by means of adding-wheels set progressively by the passage of the cards or strip. Type-wheels 2. Fig. 1, usually ten in number and bearing numeral types t‹ t<9>, are carried by a shaft 1 rotating synchronously with rollers 27, Fig. 2, for feeding cards 126 past contacts 28, 28<1>, 28<11> - - in circuit with magnets 14. 14<1>, 14<11> - - controlling hammers 7 which are connected to actuating- springs 11 and have arms 10 normally latched by the armatures 13 of the magnets. The types print on a web 18 which passes from a roll 20 to feed-rollers 19 and is led through a guide 21, an ink ribbon 22 being arranged between the hammers and the web. When a perforation in the card passes a contact, the associated magnet attracts its armature and the hammer is swung to print from the type corresponding to the perforation. The arms 10 are provided with springs 16 which co-operate with pins 17 to retract slightly the hammers after impression. The hammers are periodically restored by means of a bar 23 actuated by arms 24 on the shaft 1. To permit momentary arrest of the type-wheels during impression, the type-wheels are coupled to the shaft 1 by means of springs 5 connected to pins 6, 3 on the type-wheels and shaft the pins 3 passing through slots 4 in the type-wheels. The typewheels and hammers are controlled for total printing by means of adding-apparatus, for instance that described in Specification 194,832, the adding-wheels 42, 42<1>, 42<11> being loosely mounted on a shaft 43, Fig. 3, and engaging pinions 44 which co-operate with nine-toothed pinions 40 on a shaft 41 rotating synchronously with the shaft 1. The pinions 40, 44 are normally disengaged, spring-urged rock-arms 45 carrying the pinions 44 being held by the armatures 47 of magnets 48, 48<1>, 48<11> - - which are in circuit with the magnets 14, 14<1>, 14<11>- -. When a perforation in the card passes a contact, the associated pinions 44, 40 are permitted to engage, and the adding-wheel is rotated through an arc proportional to the number represented by the perforation. The adding-wheels 42 have pawls which rest in a notch in the shaft when the adding-wheels are in zero position, the pawls receding from the notch when the adding-wheels are operated. The adding-wheels co-operate with spring plungers 49 adapted to close contacts 54, 54<1>, 54<11> - - in circuit through normally open contacts 56, 56<1>, 56" - - with the magnets 14, 14<1>, 14<11> - -. To print a total, the contacts 56, 56<1>, 56" - - are closed and the shaft 43 is coupled to the shaft 1 and rotated through one revolution to zeroize the adding-wheels. The adding- wheels are differentially coupled by the pawls to the shaft and thereupon by means of the plungers 49 close the contacts 54, 54<1>, 54<11> - -, the magnets 14, 14<1>, 141<SP>1> - - being thereby energized and causing the hammers to print the total.