Patent GB-1420577-A (GB)
Title: Automatic stacking machine for the stacking of layers of bars in particular rolled shapes
IPC: B65G57/18
Filed: 1974-03-04
Abstract: 1420577 Stacking bars; endless chain and roller conveyers CARL KRASNY & ASSOCIATES Inc 4 March 1974 [2 March 1973] 9621/74 Headings B8A and B8C Stacking device.-A device for stacking layers of bars, such as rolled angle irons, comprises parallel spaced first chain conveyers 12 along which the bars are carried into engagement with fixed stops 20. A group of bars is lifted over the stops by traversing carriages 31 on to second chain conveyers 19. Partway along the chain conveyers 19 are withdrawable stops 23 against which the group is consolidated. After consolidation the stops are withdrawn and the group is moved against stops 29 by traversing carriages 44 similar to carriages 31 and is deposited upon a roller conveyer 62, 63, 66, 67. When a stack of groups of the desired height has been formed the stack is moved laterally off the roller conveyer, strapping being applied during removal by a known type of device 87. Pivotal magnetic heads 53 are provided between the conveyers so that selected groups, perhaps alternate groups or just the top group, can be deposited upside down on the stack. During such inversion the traversing carriages 44 are inoperative. The device is of modular construction in that it is split into two halves (about the line A-A in Fig. 1), the drive components of each half being interconnected by clutches B, C, &c. For long bars, e.g. 60 ft., the two halves are used whilst for shorter bars, e.g. 30 ft., only one half is used. Chain conveyers.-Each conveyer 12 is driven intermittently by a drive-shaft 10 so that successive batches of bars are forwarded against the fixed stops 20. Located just in front of the fixed stops are rails 22 which may be raised above the level of the conveyers 22 to support bars which, if only supported by the conveyers, would tend to override when halted by the stops. After every batch has been forwarded against the stops, probes 42 are raised to sense the presence of a bar. Should a bar be sensed then the intermittent movement of the conveyer is halted to allow a group of bars to be transferred on to the second conveyers 19. However, if a bar is not sensed then movement of the conveyers continues until a bar is sensed and movement is halted. A group of bars is then transferred over the stops into the second conveyer by devices 31 each having a plate mounted upon an arm 33 carried by a carriage reciprocated along rails 35 by a link mechanism 39,40 driven by a shaft 38. Vertical movement of each plate is effected by a bracket 33a pivotable by a piston 33b upwardly into engagement with the undersurface of the plate. A group of plates thus transferred on to the second conveyers 19, which also comprise chains driven by a common shaft 17, moves into engagement with stops 23, movement of the conveyer being continued for a time after contact of the bars with the stops to ensure consolidation of the group. The stops are then pivoted by cylinder 26 to a withdrawn position and the conveyers 19 re-started to move  the group into engagement with end stops 29. The group is lifted over the stops by devices similar to devices 31 described above or by magnetic heads 53, each mounted on arms and pivoted between its extreme working positions (see arc 55 in Fig. 9) by a gear 56 which is engaged by a segment 59 pivoted about a shaft 58 by a piston 56. Roller conveyer.-The roller conveyer, on to which the groups of bars are deposited by the devices 31 or heads 53, comprises a series of pairs of horizontal rollers 62, 63 and vertical guide rollers 66, 67. The horizontal rollers are driven through bevel gearing and chains (see Figs. 23, 33, 34 and 35, not shown) and are vertically adjustable by a piston-and-cylinder mechanism (see Fig. 25, not shown). The distance between the guide rollers is adjusted to  accommodate groups of different widths by a threaded rod 68 (see Fig. 36) which engages a frame 69 upon which rollers 67 are mounted.