Rope restraining and selective release device
View Patent ↗A rope restraining and selective release device is provided that may be incorporated with a carabiner or other device for selective interconnection to an anchor. The device employs a selectively rotatable cam lever with a plurality of teeth and gripping geometry that cooperates with the corresponding geometry in a rope cradle to restrain a rope. Tension in the rope will allow it to pass through the device in one direction, but tension in the opposite direction will prevent rope movement through the device.
1. A rope restraining device, comprising:
a hook adapted for interconnection to an anchor;
a cradle rotatably interconnected to the hook, the hook comprising a first side wall and a second side wall that are interconnected by a bottom wall, the first side wall and second side wall comprising a taper near the bottom wall, wherein:
the bottom wall in a lateral direction between the first side wall and the second side wall has a cylindrical profile defined by a linear cross section, and
the bottom wall is an axial direction extending from a proximal end of the cradle to a distal end of the cradle has an arcuate profile relative that extends from a bottom surface of the cradle, wherein the arcuate profile relative to the bottom surface, and wherein portions of the first side wall and the second side wall bound the arcuate profile;
a cam lever positioned within the cradle and configured to rotate relative to the cradle, the cam lever having a grip geometry comprised of a plurality of teeth that faces the arcuate profile, the grip geometry having a first lateral width at a proximal end that and a second lateral width at a distal end that is less than the width of the first lateral width;
wherein the distal end of the cam lever is biased toward the distal end of the cradle; and
wherein rotation of the cam lever separating the distal end of the cam lever from the distal end of the cradle creates an opening between the grip geometry and the bottom wall of the cradle that is adapted to receive ropes of more than one diameter; and
wherein rotation of the cam lever in an operation of the distal end of the cam lever toward the distal end of the cradle decreases the size of the opening, and prevents withdrawal of the rope from the cradle in a direction that generally corresponds with the proximal end of the cradle.
2. The device of claim 1 , wherein the cam lever has proximal hard stops and distal hard stops that cooperate with corresponding proximal hard stops and distal hard stops on the hook that limit cam lever rotation, and wherein the first side wall and second side wall of the cradle have notches that receive portions of the hook that limit cradle rotation.
3. The device of claim 2 , wherein the cam lever and cradle have different rotation limits.
4. The device of claim 1 , wherein the cam lever and cradle are rotatably interconnected to the hook by a pivot pin, wherein rope tension will impart rotation of the cradle and/or cam lever relative to the hook, and wherein the relative rotation of the cradle and the cam lever align a force vector associated with the rope tension with the pivot pin and a centroid of the hook to reduce off-axis loading of the device.
5. The device of claim 1 , wherein the grip geometry possesses a groove extending from the proximal end to the distal end.
6. The device of claim 1 , wherein the plurality of teeth are defined by structures with a short lateral edge and a long lateral edge with a groove therebetween, and wherein the short lateral edge and long lateral edge alternate from one tooth to the next.