Methods and apparatus for force management in fall protection apparatus

摘要

Methods of force management for a force management anchor (FMA) include apparatus between a post and a base plate that resist post rotation under fall loads, the apparatus resisting said rotation at a constant torque. A peak constant torque is less than a torsional “tear-out” capacity of a surface for maximizing energy absorption. While the fall force vector remains generally parallel to the base plate during a fall, the post is movable between an upstanding and a lowered orientation resulting in a variable moment arm and a resisting force that also varies for maintaining the torque substantially constant. Apparatus can include devices between the post and the base plate such as a torsion rod, a friction clutch or a cam arrangement. Other approached include designed deformation of the post itself, such as a through tapered post.

主权项

1. A fall management anchor secured to a surface, a fall force vector being applied thereto, comprising:
a base plate secured to the surface and having a threshold tear-off torque; a generally upstanding cantilever post having a post height, a proximal end connected to the base plate and having a distal end forming a moment arm to the base plate, wherein the fall force vector applied adjacent the distal end and multiplied by the post height applies a moment equal to or greater than the threshold tear-off torque, the fall force vector oriented generally parallel to the base plate, the distal end being actuable upon application of the fall force vector to move relative to the base plate between a maximum moment arm and a minimum moment arm in response to the fall force vector; and a constant torque apparatus operative between the distal end and the base plate for applying an increasing resistive force to the post, the resistive force at the maximum moment arm forming a resistive torque being less than or equal to the threshold tear-off torque, the resistive torque remaining generally constant at the base plate as the post's moment arm diminishes from the maximum to the minimum.