Technical paper . verhead outof the way. Each wire trips the levers on its side of the entry. Thewires from the set of advance vanes ahead of the barrier connectto the upper ends of the tripping levers, 7, and those from the advancevanes behind the barrier connect to the lower ends of the trippinglevers. By means of this arrangement, if a comparatively lightexplosion pressure reaches the vanes which are ahead, with referenceto a point in the entry, the weight of the vanes behind the barrierwill not have to be overcome by the wires in pulling the trippinglevers, as indicated in Plate XIV, A and
Technical paper . verhead outof the way. Each wire trips the levers on its side of the entry. Thewires from the set of advance vanes ahead of the barrier connectto the upper ends of the tripping levers, 7, and those from the advancevanes behind the barrier connect to the lower ends of the trippinglevers. By means of this arrangement, if a comparatively lightexplosion pressure reaches the vanes which are ahead, with referenceto a point in the entry, the weight of the vanes behind the barrierwill not have to be overcome by the wires in pulling the trippinglevers, as indicated in Plate XIV, A and B. The terms aheadand behind are merely explanatory, as the barrier is symmetricaland an explosion approaching from either direction will operate it. The weight carried on each supporting lever is about 150 pounds,and as the leverage is in the ratio of 2 to 1, the upward pressure onthe tripping lever is 75 pounds. The sliding frictional resistance of BUREAU OF MINES TECHNICAL PAPER 84 PLATE XIV k/lA-J rtocu fluit. A. ELEVATION OF TROUGH BARRIER WITH SIDE FRAME REMOVED, AND END VIEW.
Size: 2713px × 921px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
