Patent GB-380843-A (GB)
Title: Improvements in or relating to printing mechanism particularly applicable to statistical or like machines
Filed: 1931-06-25
Abstract: 380,843. Typewriters &c. BRITISH TABULATING MACHINE CO., Ltd., Victoria House, Vernon Place, Southampton Row, London.-(Assignees of Carroll, F. M. ; 1080, Warburton Avenue, Yonkers, New York, U.S.A.) June 25, 1931, No. 18380. Convention date, June 26, 1930. [Class 100 (iv).] Relay type-wheel actions.-In actions particularly for record-card controlled statistical machines of the kind comprising, as described for instance in Specification 289,071, [Class 100 (iv), Typewriters &c.], a rotary drum carrying pivoted type-bars, and a stationary callmechanism for causing a selected type-bar to swing towards the platen, the type-bars swing forwardly in relation to the drum. The arrangement enables the machine to work at a high speed since the type-bars have a low velocity relatively to the drum, and moreover the devices for swinging the type-bars may include means such as cams for regulating the velocity. In the action shown in Figs. 3 and 4, a rotary drum 10 is provided with a number of rings of pivoted type-bars 61, each ring being associated with a call mechanism which is mounted on a stationary support 19 and comprises a magnet 41 controlling a sliding interponent 54. Each type-bar is provided with a pivoted latch 63 formed with a tail 72 and a cam 70 co-operating with a finger 71 on the type-bar and the interponent respectively, another finger 68 normally co-operating with the latch to hold the typebar in contact with a cushion 67. The armature 42 of the magnet is connected to a pawl 45 which is carried by a rocking arm 47 and cooperates with a ratchet-wheel 39, a spring 49 normally disengaging the pawl. The arm 47 is held in normal position by a detent 50 and carries a pivoted member 51 abutting on a bell crank 52 which supports a rod 53 abutting on the interponent. On energization of the magnet, the pawl is coupled to the ratchet wheel and the interponent is raised and is struck by the tail of the adjacent latch, the latch being thereby rapidly swung and by means of the cam 70, causing the type-bar to be swung rapidly into contact with the platen 60. The cam is preferably so designed that the type-bar is initially accelerated and then moves at a constant velocity. After impression, the type-bar rebounds from the platen and is again held by the latch. The interponent is returned immediately by one of a series of inclines 69 on the drum, the member 51 yielding to permit movement of the bell-crank 52. The ratchet wheel is formed with a cam 40 which co-operates with a bell crank 55 to return the arm 47. The ratchet wheel is formed also with a dwell for releasing the pawl. The drum 10 comprises a head 11, Fig. 4, mounted on a bearing 15 and coupled by a spring pin 28 to a head 13 mounted on a stud 18 secured to a frame 22 having rods 23, passing through sleeves 24. The head 11 supports slotted bars 12 provided with pivots 62, 63 for the typebars and latches and provided also with the cushions 67 and inclines 69. The head 11 is provided with a driving pinion 14. The stationary frame supporting the call mechanism consists of endplates 19, 20 and cross-bars 21, 31 and is supported by the bearing 15 and stud 18. Parts of the call mechanisms are mounted on plates 30 which are inserted in slots in the bars 21 and are arranged in offset tiers. The ratchet wheels 39 are secured to shafts 33 mounted on the plates 19, 20 and geared to a pinion 17 on the head 13. Upon removal of a pin 26 the frame 22 together with the head 13 and the frame 19, 20, can be moved towards the right to render accessible the call mechanism. The cross-bars 31 support conduits 56 for the leads of the magnets, and contacts 57 adapted to engage contacts 58 on the plates 30. The leads branch from cables 27 which have sufficient slack to permit movement of the head 13 towards the right.