Rope Grab
20230226382 · 2023-07-20
Inventors
Cpc classification
International classification
Abstract
The rope grab uses friction to control movement along the rope. A brake has an eye at one end and a foot at the other that extends away at an angle to a rounded toe. Optionally, the eye and foot are attached so as to swivel. A cam has an oval rocker and a lever that extends from the rocker opposite the rocker surface. The rocker surface curves eccentrically about an axis, so the rocker behaves like a cam to modulate friction on the rope. The rope extends through a slot and is pinched between an operative surface of the rocker surface and the toe. The brake and cam are held in the correct position relative to each other between two parallel walls of a housing with the eye and lever extending in generally opposite directions outside the housing. Optional springs bias the brake toe and operative surface into the slot.
Claims
1. A rope grab comprising: (a) a housing with a first wall and a second wall parallel to the first wall; (b) a brake having a beam with a beam axis, a foot angled from a foot end of the beam, and an eye at an eye end of the beam, the foot having a brake surface with a rounded toe opposite the beam, the brake mounted between the first wall and the second wall to pivot on a brake axis at the beam end and perpendicular to the beam axis; (c) a cam having a rocker and a lever extending from the rocker, the rocker having a surface generally opposite the lever that curves about a cam axis to form an operative surface, the cam mounted to pivot between the first wall and the second wall on the cam axis parallel to the brake axis; and (d) a rope slot between the toe and operative surface having a proximal end and a distal end; (e) whereby when a rope extending through the rope slot is pulled toward the distal end of the slot, the rope is pinched and captured between the toe and the operative surface by friction with the toe and operative surface, and when either the lever pivots toward the distal end of the rope slot and/or the housing rotates such that the eye pivots toward the distal end of the rope slot, the friction can be modulated to control how the rope slides through the rope slot.
2. The rope grab of claim 1 wherein the foot and eye swivel relative to each other on the beam axis.
3. The rope grab of claim 1 wherein the toe is textured.
4. The rope grab of claim 1 wherein the foot has a shallow rounded cutout extending between the toe and the beam.
5. The rope grab of claim 1 wherein the operative surface has a shallow rounded groove.
6. The rope grab of claim 1 wherein the rocker surface is on a cap removably attached to a rocker base.
7. The rope grab of claim 6 wherein the cap can be reoriented such that a different portion of the rocker surface is the operative surface.
8. The rope grab of claim 6 wherein the rocker base has an operative surface.
9. The rope grab of claim 1 wherein the brake has a stop to limit the amount of brake pivot.
10. The rope grab of claim 1 wherein the cam has a stop to limit the amount of cam pivot.
11. The rope grab of claim 1 further comprising a brake spring to bias the toe toward the operative surface.
12. The rope grab of claim 1 further comprising a cam spring to bias the operative surface toward the toe.
13. The rope grab of claim 1 further comprising a bridge that spans the first wall and the second wall.
14. The rope grab of claim 1 wherein the second wall can pivot on the brake axis away from the cam axis to provide access to the rope slot.
15. The rope grab of claim 1 wherein the cam is mounted to pivot by a first screw through a hole in the first wall turned into a first threaded hole on the cam axis in the rocker and a second screw through a hole in the second wall turned into a second threaded hole on the cam axis in the rocker.
16. The rope grab of claim 15 wherein the first screw is removable, and the wall rotates on the brake axis to provide access to the rope slot.
17. The rope grab of claim 1 wherein the cam is mounted to pivot by a cam axle through a hole in the first wall and press fit into a hole on the cam axis in the rocker and a screw through a hole in the second wall turned into a threaded end of the cam axle.
18. The rope grab of claim 17 wherein the screw is removable, and the second wall rotates on the brake axis to provide access to the rope slot.
19. The rope grab of claim 1 wherein the brake is mounted to pivot by an axle through a hole in the first wall, a hole through the brake on the brake axis, and a hole through the second wall.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a fuller understanding of the nature and object of the present invention, reference is made to the accompanying drawings, wherein:
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DETAILED DESCRIPTION OF THE INVENTION
[0037] The rope grab 10 of the present invention uses friction on a rope to control movement along the rope. As shown in
[0038] The brake 14, shown in
[0039] The foot 32 extends away from the foot end 64 of the beam 36 at an approximately 48° angle to the beam axis 38, as shown in
[0040] Optionally, the foot 32 is constructed so that the toe 60 is on a separable component 92, as in
[0041] Optionally, the eye 30 and foot 32 are attached so as to swivel with respect to each other on the beam axis 38. Any acceptable swivel 34 can be implemented. In the illustrated swivel 34, shown in
[0042] Optionally, the foot aperture 70 has a smaller diameter than the eye aperture 50 and the bolt 76 has a corresponding difference in diameter separated by a shoulder 82. The shoulder 82 abuts the foot flat surface 70. The shoulder 82 against the brake flat surface 70 keeps the bolt 76 from clamping the flat surfaces 48, 70 together, which would lock up the swivel 34.
[0043] The cam 16, shown in
[0044] The lever 102 extends radially from the side of the rocker 100 opposite the rocker surface 110. The lever 102 is generally straight. Optionally, it is curved, as at 120, for ergonomics and/or avoiding interference with the rope.
[0045] The curve of the outer rocker surface 110 is eccentric about the axis 104 of the rocker 100, which makes the rocker 100 behave like a cam. The half of the outer rocker surface 110 adjacent to the toe 60 is the operative surface 138 of the outer rocker surface 110. The rope 3 is pinched between the operative surface 138 and the toe 60, as described below.
[0046] Optionally, the rocker 100 is designed to operate with ropes of different structures (diameters and/or constructions). To that end, in one changeable configuration, the rocker surface 110 is on a removable cap 124, as in
[0047] The cap 124 is secured to the rocker base 126 by whatever means works. In the illustrated configuration, the cap 124 is secured by the mechanism that pivotally mounts the cam 16 to the housing 12, as described below.
[0048] The eccentricity of the surface 110 is such that both ends 116, 118 of the surface 110 independently operate as the operative surface 138 depending on the orientation of the cap 124. The end 116, 118 that is adjacent to the toe 60 is the operative surface 138.
[0049] Optionally, the rocker base 126 has a rocker base surface 132 with a similar curvature as the cap rocker surface 110. When the cap 124 is not installed, the operative surface 138 is on the rocker base surface 132.
[0050] Optionally, each end 116, 118 of the cap rocker surface 110 is shaped for ropes of different structures. At the end 116 for a larger rope, the operative surface 138 is closer to the axis 104, as in
[0051] A second changeable configuration is shown in
[0052] The cap 308 is attached to the rocker base 310 by whatever means works. In the illustrated configuration, notches 316 on the edges 318 of the cap ends 312 snap onto cylindrical surfaces 320 extending from the rocker base ends 314. In the present design, the cylindrical surfaces 320 are on dowels 322 that are attached to the rocker base 310 in holes 324. Alternatively, the cylindrical surfaces 320 can be molded as part of the rocker base 310.
[0053] The eccentricity of the surface 330 is such that both ends 332, 334 of the surface 330 independently operate as the operative surface 138 depending on the orientation of the cap 308. The end 332, 334 that is adjacent to the toe 60 is the operative surface 138.
[0054] Optionally, as with configuration of
[0055] Optionally, each end 332, 334 of the rocker surface 330 is shaped for ropes of different structures, as in the configuration of
[0056] A third changeable configuration is shown in
[0057] Optionally, as with the cap 230 described above, each end 260, 262, 264, 266 of the rocker surfaces 232, 234 is shaped for ropes of different structures, as in
[0058] In the illustrated configuration, the cap 230 is secured in the cradle 236 by a pair of pins 256. The pins 256 extend through holes 252 in one cradle wall 238, through an aligned hole 250 in the cap 230, and through an aligned hole 254 in the other cradle wall 240.
[0059] In another configuration that is applicable to all of the changeable configurations, the cap 230 is secured in the cradle 236 by ball plungers mounted within the cap 230. Spring-biased spheres in the cap 230 pop into holes in the cradle walls 238, 240. Alternatively, the ball plungers are mounted to the cradle walls 238, 240 and the cap 230 has the holes that the plungers pop into.
[0060] The brake 14 and cam 16 are held in the correct position relative to each other by the housing 12. The housing 12 has a first wall 20 and a second wall 22 parallel to the first wall 20 between which the foot 32 and rocker 100 reside. The brake 14 is mounted to pivot on a brake axis 90 and the cam 16 is mounted to pivot on the cam axis 104 which is parallel to the brake axis 90. The eye 30 and lever 102 extend in generally opposite directions outside the walls 20, 22. The toe 60 and operative surface 138 form a rope slot 24 therebetween. The rope slot 24 has two ends through which a rope 3 extends. The end at the toe 60, on the left in
[0061] The optional U-shaped bridge 18 serves as a place to rest the heel of the hand when squeezing the lever 102 to release the cam 16 and/or turning the rope grab 10 to release the brake 14, as described below. Lateral ridges 156 texture the bridge body 150 to provide grip so the user's hand is less likely to slip off when applying pressure.
[0062] For the brake 14, in the configuration shown in
[0063] In the configuration shown in
[0064] Any configuration that provides an axle where the brake 14 can pivot relative to the housing 12 is contemplated by the present invention. Examples include an axle with swaged ends, an axle with a cotter pin, a long rivet, an axle with externally threaded ends and nuts, an axle with internally threaded ends and screws.
[0065] An optional spring 164 biases the brake toe 60 toward the operative surface 138, as at 178 in
[0066] Optionally, a stop prevents the brake 14 from rotating too far in either direction. The stop includes a pin 212 in a hole 214 in the foot 32. Alternatively, the pin 212 is formed integrally with the foot 32. The pin 212 rides in a curved slot 216 in the first wall 20, where the ends of the slot 216 dictate the rotation limit of the brake 14.
[0067] As indicated above, the cam 16 is mounted to pivot on the cam axis 104 within the walls 20, 22. In the one configuration, shown in
[0068] In the configuration shown in
[0069] Any configuration that provides an axle where the cam 16 can pivot relative to the housing 12 is contemplated by the present invention. Examples include an axle with swaged ends, an axle with a cotter pin or clevis pin, a long rivet, an axle with externally threaded ends and nuts, an axle with internally threaded ends and screws.
[0070] An optional spring 192 biases the operative surface 138 toward the toe 60, as at 220 in
[0071] If the rocker 100 has the cap 124 of
[0072] Optionally, a stop prevents the cam 16 from rotating too far in either direction. The stop includes a pin 222 in a hole 224 in the rocker 100. Alternatively, the pin 222 is formed integrally with the cam 16. The pin 222 rides in a curved slot 226, where the ends of the slot 226 dictate the rotation limit of the cam 16.
[0073] Optionally, the second wall 22 can swing open by pivoting on the brake axis 90 so that the user can load/unload the rope and/or to remove/swap/reverse the cap 124. To permit this, that fastener at the second wall end of the cam axle is removable. In the configuration of
[0074] The housing 12, brake 14, cam 16, and bridge 18 are composed of rigid, robust materials, such as a plastic, composite, or metal. Preferably, the surfaces that contact the rope are composed of a material that does not wear significantly during use. For example, if the cam 16 has a cap 124, 230, 308, the cap can be composed of a metallic material, while the remainder of the cam 16 is composed of a plastic, and if the brake 14 has a removable toe 92, the removable toe 92 can be composed of a metallic material, while the remainder of the brake 14 is composed of a plastic.
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[0076] The rope grab 10 is installed on the rope 3 as shown in
[0077] Opening the side wall 22 also allows the user to reconfigure the operative surface 138 of the cap 124, 230 based on user preference of line compatibility and user weight. The cap 124 of
[0078] In typical use, the eye 30 is attached to one side of the user's harness with a carabiner 8 or other connector. The distal end 4 is wrapped around a tree, anchor or other fixed object and connected to the opposite side of the user's harness by a carabiner 5. Optionally, the distal end 4 is directly clipped to an anchor or choked around an anchor point and connected back to the rope 2 with the carabiner 5 and the eye 30 is attached to a centered connection point on the user's harness.
[0079] When force is applied to the eye 30, the brake 14 rotates about the brake axis 90 until the foot 32 pinches the rope 3 against the operative surface 136. At the same time, the distal end 4 of the rope 3 is tensioned, rotating the rocker 100 to pinch the rope 3 against the toe 60. Now the rope grab 10 can be used to adjust the length of the rope 3.
[0080] To release slack and lengthen the rope 3, the lever 102 is squeezed toward the distal end 28 of the rope slot 24, as at 270 in
[0081] The curve of the operative surface 138 allows the pinching force against the rope 3 to be modulated by the user so that the length can be adjusted while under load.
[0082] To take up slack and shorten the distal end 4 of the rope 3, the proximal end 6 of the rope 3 is held and pushed toward the distal end 4, causing the rocker 100 to rotate. Rotating the rocker 100 eases the pinching pressure on the rope 3. At the same time, the user must reduce the force being applied to the brake 14 via the eye 30, which eases the pinching pressure so the rope 3 can slide through the rope slot 24 toward the proximal end 6.
[0083] Thus, it has been shown and described a rope grab. Since certain changes may be made in the present disclosure without departing from the scope of the present invention, it is intended that all matter described in the foregoing specification and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.