Force distribution and attenuation device for use in a roof anchor safety system

Abstract

An anchor-to-lanyard adjustable riser cable with a choke and bearing plate. The device is positioned between a roof truss and a safety anchor system to better distribute the weight of a roofer on the truss in the event the roofer falls. The bearing plate is configured to engage a portion of the truss and to distribute forces into this structural member, thereby leading to attenuation of those forces. The bearing plate is provided with a non-skid surface to resist movement of the same along the structural member. Guide channels are provided on the bearing plate to receive portions of the cable from the cable choke therethrough. The bearing plate aids in protecting the structural member from being damaged by a lanyard extending to the safety harness in response to forces generated by the falling roofer.

1 . A force distribution device for securement between a structural member disposed a distance vertically above the ground and a safety harness lanyard worn by a person, said device comprising;
 a cable choke adapted to engage the safety harness lanyard; and   a bearing plate engaged with the cable choke and adapted to engage a portion of the structural member; said bearing plate being configured to distribute forces into the structural member that are generated by the weight of the person falling toward the ground.   
     
     
         2 . The force distribution device as defined in  claim 1 , wherein the bearing plate is a bracket having a first leg and a second leg, wherein the first and second legs are disposed at an angle to each other, and wherein the second leg is adapted to abut the structural member. 
     
     
         3 . The force distribution device as defined in  claim 2 , further comprising:
 a first face provided on the second leg and adapted to abut the structural member; and   a non-skid surface provided on the first face.   
     
     
         4 . The force distribution device as defined in  claim 3 , wherein the non-skid surface comprises at least one groove or ridge provided on the first face. 
     
     
         5 . The force distribution device as defined in  claim 4 , wherein the bearing plate has a longitudinal axis that is adapted to be aligned with a longitudinal axis of the structural member, and wherein the at least one groove or ridge is disposed substantially at right angles to the longitudinal axis of the bearing plate. 
     
     
         6 . The force distribution device as defined in  claim 4 , wherein the second leg extends outwardly from the first leg and terminates in an edge disposed substantially parallel to the first leg, and a plurality of alternating grooves and ridges are provided in the first face of second leg between the first leg and the edge thereof. 
     
     
         7 . The force distribution device as defined in  claim 6 , wherein the plurality of grooves and ridges cover substantially the entire first face. 
     
     
         8 . The force distribution device as defined in  claim 4 , wherein the second leg extends outwardly from the first leg and terminates in an edge disposed substantially parallel to the first leg, and wherein the second leg further has opposing sides extending between the first leg and the edge, and wherein the at least one groove or ridge extends for at least a partial distance between the opposing sides. 
     
     
         9 . The force distribution device as defined in  claim 3 , wherein the non-skid surface comprises a gripping compound or an abrasive compound applied to the first face of the second leg. 
     
     
         10 . The force distribution device as defined in  claim 2 , further comprising:
 a first guide channel provided on the first leg of the bearing plate, and   a cable provided in the cable choke, and wherein a first portion of the cable is received through the first guide channel.   
     
     
         11 . The force distribution device as defined in  claim 10 , wherein the first guide channel comprises one of a first aperture defined in the first leg and a first tubular element disposed on the first leg, where the first aperture extends between a first face and a second face of the first leg, and the first tubular element is disposed on the second face of the first leg and generally parallel to a longitudinal axis of the bearing plate. 
     
     
         12 . The force distribution device as defined in  claim 10 , further comprising:
 a second guide channel provided on the first leg of the bearing plate a spaced distance from the first guide channel, and wherein a second portion of the cable is received through the second guide channel.   
     
     
         13 . The force distribution device as defined in  claim 12 , wherein the second guide channel comprises one of a second aperture defined in the first leg and a second tubular element disposed on the first leg, where the second aperture extends between the first face and the second face of the first leg, and the second tubular element is disposed on the second face of the first leg and generally parallel to the longitudinal axis of the bearing plate. 
     
     
         14 . The force distribution device as defined in  claim 10 , further comprising:
 a second guide channel provided on the second leg of the bearing plate, said second guide channel being generally aligned with the first guide channel on the first leg, and wherein a second portion of the cable is received through the second guide channel.   
     
     
         15 . The force distribution device as defined in  claim 14 , further comprising:
 a third guide channel provided on the first leg of the bearing plate a spaced distance from the first guide channel, and wherein a third portion of the cable is received through the third guide channel; and   a fourth guide channel provided on the second leg of the bearing plate, said fourth guide channel being generally aligned with the third guide channel on the first leg, and wherein a fourth portion of the cable is received through the fourth guide channel.   
     
     
         16 . The force distribution device as defined in  claim 15 , wherein the third guide channel comprises a third aperture defined in the first leg and extending between the first and second faces thereof; and the fourth guide channel comprises a fourth aperture defined in the second leg and extending between the first and second faces thereof. 
     
     
         17 . The force distribution device as defined in  claim 15 , wherein the third guide channel comprises a third tubular element provided on the second face of the first leg and the fourth guide channel comprises a fourth tubular element provided on the second face of the second leg 
     
     
         18 . The force distribution device as defined in  claim 3 , wherein the first leg of the bearing plate further comprises:
 a first arm disposed generally at right angles to the second leg of the bearing plate;   a second arm disposed generally at right angles to the second leg of the bearing plate; and   a gap defined between the first and second arms, and wherein the bearing plate is adapted to receive a portion of the structural member in the gap.   
     
     
         19 . A safety anchor system for a person comprising:
 a harness adapted to be worn on the body of the person;   a force distribution device adapted to engage a structural member disposed a distance vertically above the ground; and   a lanyard extending between the harness and the force distribution device; and wherein the force distribution device comprises:
 a cable choke selectively engageable with the lanyard; and a bearing plate engaged with the cable choke and adapted to engage a portion of the structural member; said bearing plate being configured to distribute forces into the structural member that are generated by the weight of the person falling toward the ground. 
   
     
     
         20 . In combination,
 a roof truss including a truss rafter, said roof truss being disposed a distance above the ground;   an anchor plate secured to the roof truss;   a harness adapted to be worn on the body of a roofer;   a force distribution device selectively engageable with a portion of the roof truss; said force distribution device comprising:
 a cable choke secured to the anchor plate; 
 a bearing plate engaged with the cable choke and disposed in abutting contact with truss rafter; and 
 a lanyard extending between the harness and the force distribution device; wherein said bearing plate is configured to distribute forces into the truss rafter that are generated by the roofer falling toward the ground. 
   
     
     
         21 . The combination as defined in  claim 20 , further comprising a non-skid surface provided on the bearing plate, said non-skid surface resisting movement of the bearing plate along the truss in the event the roofer falls toward the ground. 
     
     
         22 . The combination as defined in  claim 21 , wherein the cable choke and bearing plate transfer a load on the lanyard from the anchor plate to a top region of the truss rafter.