| 摘要 |
A mine roof truss and components thereof, the same including end support brackets, mine roof support plates, and associated structure. The truss structure is designed for maximum strength, and its mine roof support plates are designed for improving truss integrity and also for insuring that the stirrups used suitably preserve the integrity of the truss structure as well as provide safety features for stirrups to be placed under stress when such stirrups are loose or in a hanging position. The mine roof support plates utilized include depending horn portions having respective reaction surfaces for engaging stirrups to be placed in tension, and additionally, provide J-shaped lips forming cradles for the stirrups when the latter are in a hanging or loose position. In this way, the stirrups are preserved against dislodgement and free-fall within the mine which might contribute to a dangerous condition to workmen. The stirrups themselves are of hairpin configurement, having a cylinder welded at its sides to opposite end portions of the stirrups. In this way, maximum strength is preserved and, in addition, facility is provided for including within the stirrup elongate bars of the truss that are to be placed in tension.
|
