Patent GB-534032-A (GB)
Title: Improvements relating to printing mechanism for accounting machines
IPC: G06C11/04
Filed: 1939-08-22
Abstract: 534,032. Calculating-apparatus. UNDERWOOD ELLIOTT FISHER CO. Aug. 22, 1939, No. 24144. Convention date, Dec. 30, 1938. [Class 106 (i)] In a machine with printing mechanism having a plurality of type supports with character, zero and digital type elements and in which means are provided for printing zero instead of characters to the right of the highest significant digit, the character type are mounted on auxiliary supports movable relatively to the main type supports for enabling the printing of the zeros. The invention is shown applied to a machine as described in Specification 401,904. The type elements are carried on bars 3, Figs. 3 and 6. the vertical movement of which is controlled, during a machine operation, by the engagement of rods 13, attached to the bars, with pins 11 projected by depression of the amount keys 12. The impression hammers 23 are held by latches 38 with overlapping projections 44 so that when the left hand latch is tripped during a normal operation of the machine all the hammers are released. The tripping action is effected by a lever 28 pivoted on a rod 27 supported by arms 25, 26 from a shaft 24 and operatively connected by means (not shown) to the main operating shaft 18. The lever 28 is formed with a projection 31 which bears on the overturned end of a lever 32, the other end of which normally engages the lower surface cf an arm 34 pivoted on the shaft 36. By this means special type characters such as asterisks are printed to the left of an amount. The printing of special characters is desirable when printing amounts upon bank cheques but is unnecessary when tabulating on journal sheets. To prevent printing to the left a release key 51 is depressed to rock an arm 54 about its pivot 53 which strikes a pin 62 on a link 55 connected to the cranked end of the shaft 36 thereby rocking the shaft 36 which displaces the arm 34 to bring a step 63 thereon over the end of the lever 32 which rocks under the action of the spring 37 and lowers the operative end of the lever 28 to ineffective position. Tripping of the hammers corresponding to the digits of an amount set up is effected in the known manner by spring controlled arms 64, pivoted on rod 27, normally engaging studs 65 on the type bars ; when the type bars are raised the arms 64 move to bring shoulders 66 thereon into engagement with the hammer latches 38. The function of the release key may be performed automatically under control of the travelling carriage 2. For this purpose a stop 68 on the carriage co-operates with a lever 72 to operate a linkage 74, 58 to displace the link 55. Controlling printing of zeros.-To substitute zeros for the asterisks in those denominations where zero appears in the amount to be printed the type bars with the exception of the three lowest denominations, each carry a bracket 76 supported for limited movement and provided with an arm 81, Figs. 8 and 9, on which the asterisk 82 is mounted. The arm 81 is bent to lie between the zero type and the platen and its boss 83 is shaped to conform to the cavity in the face of the zero type. Each bracket has a stud 88 supported on an arm 86 pivoted on a shaft 87 and formed with a flange 91 resting upon a stud 92 of the arm of next higher denomination. The shaft 87 also carries a series of spring- controlled arms 93 each provided with a roller 94 supporting its arm 86 and normally held by the stud 96 on the type bar. When one of the higher denomination type bars is raised beyond its zero printing position the stud 92 of its arm 86 raises the lower denomination arms 86 and through their connection with the studs 88 lift the brackets 76, in those denominations where zero is to be printed, so as to move the asterisk type 82 out of the path of movement of said zero type.