Patent GB-816152-A (GB)
Title: Method of and apparatus for sorting letter mail
IPC: B07C3/02
Filed: 1956-03-07
Abstract: 816,152. Sorting letters. POSTMASTER GENERAL OF CANADA. March 7, 1956 [April 15, 1955], No. 7221/56. Class 78 (1). Apparatus for sorting letters comprises means for imposing upon each letter a pattern code interpretation of its destination, means for reading electrically the imposed codes and effecting automatically a primary sorting of the letters according to major political or geographical subdivisions, means for conveying the letters which need further sorting to secondary sorting stations provided with means for reading electrically the codes and effecting a further sorting of the letters. All letters are passed initially through coding stations 2, Fig. 1, of the kind described in Specification 757,824 where coded abbreviations of the addresses are printed on them by operators. The letters are then distributed among a number of primary sorters 3 each of which consists of a sensing device 4 and a 16-outlet conveyer 5 of the kind described in Specifications 750,422, [Group XIX], and 776,034, respectively. The terminus 7a of a branch conveyer 7 is disposed adjacent each sorter 3. The conveyers 7 feed a conveyer 9 which extends to a secondary sorting area 10. In this area sixteen branch conveyers 11 extend from the conveyer 9 to termini 11a. The conveyers 7, 11 are connected to a main return conveyer 12 by branch conveyers 13. Letters are conveyed from the sorters 3 to the termini 11a by trays 8 connected to a moving chain. Each tray carries a battery of sixteen pins, any one of which can be depressed by an operator at the terminus 7a to engage a deflecting member at a junction of the conveyers 9, 11 to divert the tray to the appropriate terminus 11a. An operator at this terminus feeds the letters into a secondary sorter which may be one of three kinds 16a, 16b or 16c. The letters passed into the sorter 16a are read by an electronic sensing device 17 and the impulses excited therein are applied to an electronic memory 18 preferably of the kind described in Specification 757,824. This memory is scanned later and effects the actuation of mechanism which directs each letter to the appropriate box. A sorter 16b is used when a terminus 11a is allocated to a large area having a number of delivery points which is too many for a single sorter 16a to deal with, but the volume of letters is not too great to be handled by a single terminus 11a. The letters are read by an electronic sensing device 17 and then passed through a high-speed printer 19 which imposes a coded box number on each letter. Thereafter sorting is effected by direct-action sensing devices 20 which divert the letters to either one or the other of the sorters 16b where further sorting is effected by direct-action sensing devices 20a. One of the sorters 16c is used when the volume of the mail for a particular area is too large to be handled by a single conveyer at a terminus 11a and the total number of delivery points within the area is larger than that which can be sorted by a single sorter 16a. After passing a printer 19 and a sensing device 20, the letters are distributed by all but one of the devices 20 among conveyers 39b, each of which leads to a storage and transfer device 39. Each device 39 transfers the letters to one of four conveyers 39a, each of which leads to a sorter 16c controlled by a direct action sensing device 20. The remaining device 20 distributes the letters directly between the conveyers 39a. A storage and transfer device is shown in Fig. 7 which transfers letters from a conveyer 55 to a conveyer 67 at a controlled rate. It consists of a series of narrow boxes 56 held on edge between two sets of parallel tracks 57, 58 and propelled by a rubber driving belt 61. Each box has an open end 59 and a hinged bottom 60 which is held closed by a plate 69 extending between the tracks. Each box is stopped by a lock pin 63 when its open end 59 is in register with the end of the conveyer 55. The position of the lock pin is controlled by photo-electric cell apparatus 64, 65. As each letter passes into a box an impulse is excited in cell 64 which is adapted to withdraw the pin 63 for a length of time sufficient for the box to move from the end of the conveyer, but not sufficient for the next box of the series to pass beyond it. The boxes move along the tracks 57, 58 until stopped by a pin 66 which is slightly in advance of a gap 70 in the plate 69. This pin is withdrawn when a signal received from photo-electric cell apparatus 71 indicates that there is space on the conveyer 67 for a letter. As the leading box moves forward its bottom opens and the letter contained therein is transferred to the conveyer 67. Reference has been directed by the Comptroller to Specification 757,824.