GB491190A - A flap device for skips and hoppers - Google Patents

Abstract

491,190. Guided skip hoists; ships; delivering material from hoppers. AUTOMATIC COAL CLEANING CO., Ltd. Jan. 24, 1938, Nos. 2275 and' 2276. Convention dates, Feb. 22, 1937 and Aug. 28; 1937. [Classes 78 (i), 78 (iii), and 78 (iv)] The hinged bottom door 3 of a skip, which is pivoted at 4, is normally held closed by pivoted links 5 carrying rollers 7 bearing against the outer ends of slots 9. As the raised skip approaches the dumping point, the rollers engage fixed guides 15 and are moved towards the left until the links pass the vertical position and allow the door to open. In the meantime the upper end of the door has passed the fixed stops 16, and the rollers 13 drop on to these stops and support the door so that it opens gradually as the lifting continues until finally it forms a delivery slot approximately in line with the surface 32. During the latter part of the opening movement the depending links 5 are dragged by the door until the rollers are again at the right-hand ends of the slots, in which position they support the open door just clear of the stops 16. On lowering the skip, the stops 16 initiate the closing movement of the door and the guides 15 complete it. Similar apparatus may be used to open and close the door of a fixed bunker for charging skips. In this case the link is hauled in both directions by a motor so that the roller is displaced from end to end of the slot. Fig. 5 shows the means adopted to prevent interference with the closing of the door by jamming at the hinge. The door plate 33 is bent right round the hinge 4 and terminates in a curved portion 38 that co-operates with the tapered end of the fixed wall 32 to remove collected material as the door closes. For narrow shafts the door is formed with a tailpiece extending below the hinge and the link and roller are fitted thereto. Fig. 7 shows a modified construction in which the door is supported by the spring 61 in the open position, and the slot 51 is made long enough to allow the door to compress the spring and move down to the position 63 if the roller 59 strikes the upper guide 57a in the event of an overwind. In the position 63 the door can slide over the inner surface of the guide without being fractured. In a modification of the construction shown in Fig. 7, the link and slot are below the door instead of above it. In a further modification, the door is moved to its lowest position on overwind, by a cam which normally supports it in the open position but is rotated by contact with a fixed stop in the shaft so that it allows the door to fall to the position in which it is free of obstructions.