GB1312591A - Door latching mechanism - Google Patents

Abstract

1312591 Latching devices for doors; door operating mechanism COAL INDUSTRY (PATENTS) Ltd 17 Dec 1971 [5 Jan 1971] 487/71 Headings E2A and E2M A door latching mechanism comprises a pivotally mounted latching arm member 21, a latch 25 carried by the arm, a keeper part 31 on a door 3 to be latched, an operating device 12 including a reciprocating drive member, a guide member 15 connected to the drive member, the guide member co-operating with a guide part 9 on the door, and the operating device also including a release part 34 having a profiled camming surface 35 adapted to engage the latching arm member and to move it from a latching to a non-latching position. As shown, hinged doors 3, 4 at the bottom of a hopper 1 have flanged plates 7, 8 provided with studs 9, 10 which move in slots 17, 18 of guide bars 15, 16 pivoted on a cross-bar 14. The latter is pivotally connected to a shaft 13 driven through gearing by an electric motor and provided with an extension 34 formed with camming surfaces 35, 36. The shaft is first driven downwards to relieve the guide bars of the weight of the doors and then further driven downwards so that the surfaces 35, 36 are introduced between the rollers 37, 38 on latching members 21, 22 which are pivoted outwardly against the bias of a spring 33 and released from engagement with keepers 31, 32 on the doors, the latter then swinging downwardly about the hinges 5, 6. On upward movement of the drive shaft, the cross-bar 14 and guide bars 15, 16, the bottom of the slots 17, 18 engage the studs 9, 10 to draw up the doors and allow the latches to engage the keepers 31, 32. The device may be used to operate one or more doors, and two latching mechanisms, one at each end of a hopper, may be operated in unison.