Eddy current braking device for rotary systems

Abstract

An apparatus has a first portion of a magnetic braking system with a first element disposed thereon. The first portion rotates about an axis. The position of the first element is a fixed distance from the axis. A second portion of the magnetic braking system has a second element disposed thereon. A spring biases the rotatable first portion a first distance from the second portion. Upon application of a force to one of the portions, the relative position of the rotatable first portion to the second portion is reduced to a second distance less than the first distance.

What is claimed is: 
     
         1 - 22 . (canceled) 
     
     
         23 . An auto belay device comprising:
 a rotatable drum;   a length of material wrapped at least partially around the rotatable drum, wherein a weight is configured to be applied to an end of the length of material; and   an eddy current braking system configured to generate a braking force to slow or stop an unwrapping of the length of material from the rotatable drum, wherein the braking force applied by the eddy current braking system varies with the applied weight and stronger braking forces are generated for heavier applied weights, and wherein the eddy current braking system comprises:
 at least one magnetic element; 
 at least one conductive element; and 
 a biasing element coupled to the rotatable drum, wherein the at least one magnetic element or the at least one conductive element is coupled to the rotatable drum, wherein the rotatable drum is movable from a first distance towards a second distance, and wherein movement of the rotatable drum moves the at least one magnetic element relative to the at least one conductive element based on the application of the weight on the length of material and against a biasing force of the biasing element. 
   
     
     
         24 . The auto belay device of  claim 23 , wherein the biasing force of the biasing element is adjustable. 
     
     
         25 . The auto belay device of  claim 23 , further comprising a transmission rotatably coupling the rotatable drum and the at least one magnetic element or the at least one conductive element. 
     
     
         26 . The auto belay device of  claim 25 , wherein rotation of the rotatable drum and the at least one magnetic element or the at least one conductive element are in the same rotational direction. 
     
     
         27 . The auto belay device of  claim 25 , wherein the transmission includes at least one gear. 
     
     
         28 . The auto belay device of  claim 23 , wherein the biasing element provides the biasing force orientated in a substantially vertical direction. 
     
     
         29 . The auto belay device of  claim 23 , wherein the rotatable drum is mechanically linked with at least a portion of the eddy current braking system. 
     
     
         30 . An eddy current braking system comprising:
 a rotatable drum having a length of material wrapped at least partially around the rotatable drum, wherein a weight is configured to be applied to an end of the length of material;   a biasing element coupled to the rotatable drum, wherein the rotatable drum is moveable from a first distance towards a second distance based on the application of the weight on the length of material against a biasing force of the biasing element;   a first eddy current braking element that includes at least one magnetic element or at least one conductive element;   a second eddy current braking element that includes the other of the at least one magnetic element or the at least one conductive element; and   a linkage coupled between the first eddy current braking element and the rotatable drum, wherein the linkage at least partially transfers movement of the rotatable drum into corresponding displacement of the first eddy current braking element relative to the second eddy current braking element so as to generate an eddy current braking force.   
     
     
         31 . The eddy current braking system of  claim 30 , wherein the first eddy current braking element is rotatable, and wherein the system further comprises a transmission rotatably coupling the rotatable drum to the first eddy current braking element. 
     
     
         32 . The eddy current braking system of  claim 30 , wherein the linkage is pivotable about a fixed pivot point. 
     
     
         33 . The eddy current braking system of  claim 30 , wherein the second eddy current braking element is fixed within the system. 
     
     
         34 . The eddy current braking system of  claim 30 , wherein the biasing element is fixed at an anchor within the system. 
     
     
         35 . The eddy current braking system of  claim 30 , wherein the first eddy current braking element includes the at least one conductive element and the second eddy current braking element includes the at least one magnetic element. 
     
     
         36 . The eddy current braking system of  claim 35 , wherein the at least one conductive elements comprises a plurality of conductive elements and the at least one magnetic element comprises a plurality of magnetic elements, and wherein each of the plurality of conductive elements is received by a corresponding magnetic element of the plurality of magnetic elements. 
     
     
         37 . A method of generating an eddy current braking force comprising:
 biasing a first datum of a magnetic element relative to a second datum of a conductive element at a first distance via a biasing element; and   applying a weight to one of the magnetic element or the conductive element, wherein the applied weight moves the first datum and the second datum towards a second distance relative to one another and against a biasing force of the basing element,   wherein the proximity of the first datum relative to the second datum generates the eddy current braking force, and wherein heavier weights generate stronger braking forces and closer second distances.   
     
     
         38 . The method of  claim 37 , further comprising rotating the conductive element around the second datum. 
     
     
         39 . The method of  claim 38 , further comprising rotating the magnetic element around the first datum. 
     
     
         40 . The method of  claim 39 , wherein a rotation direction of the conductive element is opposite of a rotation direction of the magnetic element. 
     
     
         41 . The method of  claim 37 , wherein magnetic fields form by the magnetic element increase in intensity with closer distances to the first datum. 
     
     
         42 . The method of  claim 37 , wherein the conductive element has a smaller cross-sectional area at farther distances from the second datum.