GB939233A - - Google Patents

Abstract

939,233. Selective printing. POSTMASTER GENERAL. Jan. 19, 1960 [Jan. 23, 1959], No. 2626/59. Class 100 (4). [Also in Groups XIX and XXX] A printing machine for marking codes on letters 1 in a letter-sorting apparatus comprises helices 29 for feeding the letters one-by-one to a coding position B having fourteen hammer rods 12 selectively operated by a keyboard K to transfer a phosphorescent substance carried on a transfer ribbon 19 on to the letter 1. The town destination code, e.g. the first three and last two letters, is translated at T into a binary code and entered in a data store S, from where it is read out to operate certain electromagnets 13. The armatures cause levers 14 to engage the appropriate hammer rods 12 which pass through an aperture 6 in a face-plate 5 and the phosphorescent substance described in Specification 870,504 is transferred. After marking the letters pass in front of a low-pressure ultraviolet source 23 so that the marks are activated and the letter is then passed in front of a slit 24 in the tube of a photo-multiplier housing 25. The code thereby read is compared at 37 with the data stored and if the two are identical the letter is allowed to proceed to the sorting apparatus. The hammer rods are heated by electrical elements in the block 15 controlled by a thermostat. In a modification the hammer rods are mounted in a housing which swings all the hammer rods into contact with the transfer ribbon but only those which are to effect transfer are heated. The hammer mounting blocks are resiliently mounted to accommodate varying letter thicknesses. Specifications 656,873 and 768,504 also are referred to.