CPC B66B 9/08 (2013.01) [B66B 9/083 (2013.01); B66B 9/0815 (2013.01); B66B 9/16 (2013.01); B66B 9/193 (2013.01); F16D 13/12 (2013.01); F16D 49/04 (2013.01); F16D 51/04 (2013.01); F16D 59/00 (2013.01)] | 7 Claims |
1. An overspeed braking apparatus for use in slowing and ultimately stopping a moving load exceeding a pre-set operating speed, comprising:
a band brake comprising:
a circular brake drum having an axis;
one or more windings of a band wound circumferentially about the brake drum, opposing ends thereof being connected to the moving load; and
an escapement operatively arranged intermediate the moving load and the band brake for latching at speeds exceeding the pre-set operating speed and engaging the band brake to limit impact loading and to slow the moving load to a controlled stop, wherein the escapement comprises:
a toothed gear rotatably supported concentrically and coaxially within the brake drum and operatively connected to the moving load for rotation with movement thereof;
a rocking pawl pivotally supported in the brake drum, the pawl engaging teeth on the toothed gear; and
biasing means for biasing the pawl into engagement with the toothed gear, wherein at or below the pre-set operating speed, the pawl rocks reactively as the teeth on the gear engage the pawl, the biasing means acting to move the pawl toward the brake drum for preventing the pawl from latching to the gear; and
wherein at the speeds exceeding the pre-set operating speed, the biasing means cannot bias the pawl quickly enough to move the pawl away from the teeth and the pawl latches thereto, causing the toothed gear to rotate with the brake drum and apply tension to the band for slowing and stopping movement of the moving load.
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