Patent GB-850342-A (GB)
Title: Improvements in the manufacture of magnetic core arrays
IPC: H01F27/00
Filed: 1956-11-16
Abstract: 850,342. Construction of magnetic information-storage apparatus. INTERNATIONAL BUSINESS MACHINES. Nov. 16, 1956 [Nov. 21, 1955], No. 35147/56. Class 40 (9). A magnetic core memory array comprises an assembly of moulded combs 2, Figs. 14, 15, 18, 19 each of which accommodates annular magnetic cores 240 in core receiving pockets 13 located along opposite edges, the pockets being separated by comb teeth 14 and arranged to open alternately on opposite surfaces of the comb so that when a number of pre-wired cores is fitted, the wiring 171 passes in zig-zag fashion as shown over and between the core teeth. The comb is formed with wiring apertures 243 for circuits not required to pass through the cores, and has grooves 15 for accommodating the core wiring where it passes over the comb teeth. A comb fitted with its cores and wiring has terminal units 8, 10 carrying terminals 11, 12 secured to its ends, and a group of combs is held together in assembled relationship by rods passed through holes 16, 16a. Mounting cores and wiring on a comb. A machine is described, Figs. 1 to 5, which automatically mounts the cores and associated wiring in the required manner along an edge of a comb. The comb 2 is secured to a support member 26, Fig. 1, which rotates with shafts 22, 24. and is so positioned that the comb core pockets 13 along one edge are coaxial with the shafts. The cores are initially stacked in a magazine 170 with the associated wiring 171 passing through the core centres and between two teeth of the comb. Shafts 22 and 24 are arranged to move axially and are biased to the left by a spring 31, the axial movement proceeding step-by-step under the control of a pawl 40 and a rack 38 the teeth spacing of which correspond to the distance between adjacent core pockets. The rack is also arranged to move to the right over a distance corresponding to onethird of the rack tooth interval and is normally biased to the left by a spring 52. The machine is driven from a shaft 108 which carries gears 118, 119 toothed over only one-half of their periphery so that shafts 70 and 90 rotate alternately. Shaft 70 drives cam shaft 86 through gears 78, 84 while shaft 90 causes shafts 22, 24 to rock the comb backwards and forwards through an angle of 240 degrees by means of a link mechanism 140 and gears 36, 142, the latter feature enabling the cores to be inserted alternately into core pockets on opposite surfaces of the comb. In operation shaft 70 is first to rotate, and a horseshoe magnet 100 is lowered to a horizontal position adjacent wire 171 by disengagement from a cam 72 on the shaft. A cam 76 also on shaft 70 then releases a spring bell-crank 178, 180 which draws back a slide member, Fig. 8, so that a single core 196 passes down the wire 171 and the next core in the magazine drops on to a fixed platform 193. The released core is arrested and held by the field of the horseshoe magnet 100. At this stage the comb rests in the horizontal position as shown in Fig. 5. The released core is then seated into a core pocket by a vertical core seating element 98 which is released by a cam 74 also on shaft 70. Final seating of the core is effected by an arm 170 which moves the core horizontally into an undercut recess 217, Fig. 17, in the core pocket. This arm is deflected by a cam 88 on shaft 86 which operates a forked rocking arm 94 in the manner shown in Fig. 6, the arrangement being such that arms 150 and 148 act in turn as horizontal seating members when the comb rocks backwards and forwards and presents the comb teeth alternately in opposite directions. The magnet 100, the core seating element 98, the arm 150 and the slide member 188 are then restored to their initial positions, the latter member feeding the core on the fixed platform into a release position in preparation for the next operating cycle. At this stage the drive is transferred from shaft 70 to shaft 90 by the half-toothed gears 118, 119 and the comb commences to rotate in the anti-clockwise direction as viewed in Fig. 5. After the comb turns through an angle of 30 degrees, the link mechanism 140 reverses the direction of rotation. At this point a cam 92 on shaft 90 disengages from a pivoted crank 226 and permits the rack 38 to move to the left under the action of spring 52. In consequence the comb is displaced in the same direction by a distance of one-third of the core pocket interval. As the wire is positioned in the longitudinal direction of the comb by a forked guide member 220, Fig. 10, it is laid against the right side of the core pocket adjacent to the comb groove 15. This guide member is carried by a partially apertured disc 164 which rotates with the comb but is mounted on a spline on shaft 22 so that it always remains in a position adjacent the magazine. The comb is next moved to the left by a complete pocket interval so that the guide member lays the wire in the groove 15. This movement is initiated by a cam 124 on shaft 90, Fig. 3, which deflects a pivoted arm 106 so that a part 126 rocks a lever 128 and frees dog 40 from the teeth of rack 38, the period of release being timed so that the shafts 22, 24 and the comb are moved to the left by one rack tooth only under the action of spring 31 before the dog re-engages. The next core pocket is thus moved to the load position, and the wire is then passed between the comb teeth and the other surface of the comb brought adjacent the magazine by rotation of shaft 22 through 210 degrees. The wire is next brought to the centre of the core pocket by movement of the rack to the right by one-third of a core pocket interval, this restoration of the rack to its original position being effected by cam 92 and crank 226. At this stage the drive is transferred from shaft 90 to shaft 70 and the loading operation is repeated in the same manner except that horizontal positioning of the core is carried out by arm 148. Formation of memory array.-The wires threaded through the cores on the combs, Figs. 19 and 33, may each comprise several conductors which are separately connected to terminals 11, 12 by dip soldering and usually form the X co-ordinate and inhibit windings. Additional terminals are used in the Fig. 19 arrangement to provide two conductors for each X co-ordinate winding, this being necessary where unidirectional drives e.g. transistors, are used for read and write purposes. The combs are assembled in groups by through bolts with terminal blocks, Fig. 30, for the Y co-ordinate and sense windings fitted to each end. The Y coordinate windings are then threaded through axially aligned cores for connection to the terminal blocks. The cores on the two edges of a comb form two separate matrix planes when a comb group is assembled. The number of cores in the X co-ordinate may be increased by connecting groups of combs end to end with their terminals 11, 12 bent as shown in Fig. 19 so as to effect electrical connections between the groups..The read-out or sensing winding is arranged to alternate in direction through the cores in the usual manner and is fitted before the combs are finally assembled by aligning subgroups of combs with cores in different rows coaxial, threading with the sensing wire, moving one sub-group relatively to the other and threading in the reveise direction. The operation is repeated until the wiring is complete and may be carried out in a sliding jig. When completed the group is assembled, the wiring tightened, and the end loops cut and individually terminated. The wiring operation is illustrated diagrammatically in Figs. 35 and 36. Arrangements of combs and windings to form double plane 20 x 38, 16 x 16 and 6 x 80 memory arrays are described, the latter array including a buffer store having a capacity of one-twentieth of the total storage space. Specification 784,549 is referred to.