Patent GB-1501300-A (GB)
Title: Materials storage apparatus
IPC: B65G1/04
Filed: 1976-03-29
Abstract: 1501300 Storage and retrieval apparatus STOPA STAHLBAU GmbH & CO 29 March 1976 [23 April 1975] 12528/76 Heading B8W Materials storage apparatus comprises a row of storage racks of which two 1, 2 are shown, the racks being arranged transversely to the longitudinal direction of the row and each being provided with horizontally-extending bearer arms 3 which define compartments for storing material such as bars 4, a mobile gantry crane 45 being movable along the row so that a cross beam 7 thereof can be lowered into and raised from an access gangway 6 provided between any two racks. Mounted on the cross beam 7 is a plurality of parallel lifting forks 8, each of which is formed of two flanges 11, 12, each fork 8 being mounted on a respective carrier arm 14 at a pivot bearing 21 so that either of its flanges can assume a substantially horizontal orientation, its other flange being substantially vertical. Each carrier arm 14 is movable on rollers 15 along a respective rail 13 located on the underside of, and extending transversely to, the cross beam 7 under the action of a motor (16), Fig. 3 (not shown), which drives a lead screw 17 on which a follower nut 20 on the carrier arm 14 is received. A tilting lever 22 is pivotally mounted at 23 on each carrier arm 14, the lever 22 having a projecting pin 24 and roller 26 at its upper end as well as projecting pegs 27, 28 at its pivot mounting and lower end respectively. The pin 24 is received in a slot 25 in the carrier arm 14. In the condition of the apparatus shown in Fig. 2 the flange 11 of the fork 8 is in position to retrieve a load from a storage rack, the fork 8 being prevented from rotating anti-clockwise by the engagement of its flange 12 with the peg 27. The pin 24 is at one end of the slot 25 due to the engagement of the roller 26 with an end stop 18 provided on the lower side of the rail 13. When the carrier arm 14 is driven by the lead screw 17 to the right in Fig. 2 it arrives at the position shown in Fig. 3 (not shown) in which it is retracted relative to the cross beam 17, this being the travelling position of each fork 8, and the roller 26 now engages an end stop (19) at the other end of the rail 13 and tilts the lever 22 until the pin 24 engages the other end of the slot 25, and the peg 28 pushes on the flange 12 and thus tilts the flange 11 slightly upwards, so that bars 4 resting on flange 11 are prevented from falling off the fork 8 during movement of the gantry crane 45. The storage racks may be fixed, with a gangway between each pair thereof or alternatively the racks may be relatively movable to provide a gangway between two adjacent selected racks. In the embodiment of Figs. 4, 5 (not shown) each fork (8) is pivotally mounted on a lever (36) which is pivotally mounted at (37) to a respective carrier arm (35), the top of the lever (36) being connected to the pin (24) and thus to the tilting lever (22). A peg (28) at the lower end of the lever (22) prevents anti-clockwise rotation of the fork in its extended condition, Fig. 4, while in the retracted condition of Fig. 5 the same peg (28) pushes on the substantially vertical flange (12) to prevent the material rolling off the substantially horizontal flange (11). In the embodiment of Figs. 6, 7 (not shown) each tilting lever (39) is articulated, comprising an arm (40) and a pivot plate (41) which carries the peg (24) and roller (26) at its upper end, while the lower end of the arm (40) carries the peg (28) for the same purpose as in the embodiment of Figs. 4 and 5.