Patent GB-1030919-A (GB)
Title: Improvements relating to document sorting apparatus
IPC: B07C3/00
Filed: 1964-09-02
Abstract: 1,030,919. Statistical apparatus; digital data stores. INTERNATIONAL BUSINESS MACHINES CORPORATION. Sept. 2, 1964 [Sept. 4, 1963], No. 35901/64. Headings G4C and G4M. In a document sorting machine, data identifying which pocket a document is to be sorted into is entered in a first register 320, Fig. 1, and is transferred to successive registers 350-500 in accordance with the movement of the document through the machine, the contents of the registers being examined and used to operate associated sorting deflectors when appropriate. The pocket identifying data may be obtained from a magnetic read head 26 sensing the documents 10 or from a computer 200. First embodiment.-The sort control data for the first document is entered in register 305 (the detailed operation of registers 240-305 is given below) from buffer 225 when the leading edge of this document is detected by document detector DD0 The sort control data for second, third and fourth documents are similarly stored in respective registers 295, 285, 240 by the time the leading edge of the first document arrives at DD1. At this point, the sort control data for the first document is transferred from register 305 to register 320, and a 3-bit Gray-code counter 325 is started and performs one counting cycle under control of a trigger 270 which is continuously switched by impulses from an emitter 275. The sort control data for the second, third and fourth documents are shifted into registers 305-285 to make room for the sort control data for the next document. The most significant bit of the sort control data determines whether the upper or lower branch path is to be selected, and this bit is examined in register 320 to operate deflector 50 to direct the first document to the appropriate branch. By the time the first document reaches point C or I, counter 325 has reached 7, causing transfer of the data from register 320 to register 350 and starting counter 355. If the document is to be sorted into pocket 1, it will have been directed to the upper branch, and a decode circuit 351 which examines the contents of register 350, energizes magnet M1 to operate deflector 61. If the document is to be sorted into pocket 6 in the lower branch, however, magnet M1 will not be operated, but when the document reaches point J, counter 355 will cause transfer of the sort control data to register 375 and decode circuit 376 will operate magnets M2 and M6. Since documents cannot be simultaneously at points D and J, E, K &c., pairs of pockets 2, 6; 3, 7; 4, 8; 5, 9 have the same coded identity except for the most significant bit, thereby allowing the use of common decode and magnet driver circuits. The sort control data for the first and subsequent documents continue to step through the registers 320-500. A detector DD2 enables AND gate 482 if a document enters pocket 0, and if the sort control data in register 475 does not correspond with this selection an alarm circuit is energized. Similarly, if a document enters pocket 12 (also acting as a reject pocket) a detector DD3 enables AND gate 503, and if the data in register 500 does not correspond another alarm circuit is energized. Second embodiment.-The buffer 225 and detector DD1 of Fig. 1 are dispensed with. The sort control data for a document may enter register 240 at any time while the document is passing detector DD0, Fig. 16 (not shown). Passage of the leading edge of the document past DD0, however, starts a Gray-code counter 241, which on attaining a count of 7 transfers the data to register 285 and starts a counter 286. Similar counters transfer the data in turn to registers 295, 305 and thence to register 320, the operation then proceeding as in the first embodiment. Synchronization with the document movement is thus achieved by DD0 alone. Operation of registers 240-305.-Each register comprises four bi-stable stages L1, L2, L4, L8, Fig. 2a, sort control data being entered from complementary inputs through gates 241-244 and 246-249 when the associated trigger 260, 290, 300 or 310 is in the reset state. Data from the first document sets buffer 225, Fig. 1, and simultaneously enters each of registers 240-305, triggers 260-310 being reset at this time. When DD0 detects the leading edge of the document, one-shot circuit 33 conditions the set input of trigger 260, and when trigger 270 is next reset by emitter 275, trigger 260 is set. Setting of trigger 260 resets buffer 225 and conditions the set input of trigger 290, this trigger being set when trigger 270 is next set. Setting of trigger 290 resets trigger 260 and conditions trigger 300. Since buffer 225 has been reset, resetting of trigger 260 causes register 240 to be reset. Resetting of registers 285, 295 follows in a similar manner before the second document is sensed. Entry of data from the second document is similar except that, with trigger 310 set, register 305 retains the data from the first document, and after resetting of registers 240, 285, register 295 retains the data from the second document, trigger 300 also remaining set. The operation for the third and fourth documents is similar. When DD1 detects the leading edge of the first document, the corresponding sort control data is transferred from register 305 to register 320 as above described. The pulse used to gate the data into register 320 is also applied on line 324 to an inverter 323 which subsequently resets trigger 310 and thus transfers the contents of register 295 to register 305. Shortly after, trigger 310 is again set by trigger 270 and trigger 300 is therefore reset, allowing the data in register 285 to be transferred to register 295. Similar transfer from register 240 to register 285 follows, trigger 260 being reset to allow entry of data from the fifth document into register 240.