Shock Absorbers For Protective Body Gear

Abstract

A shock absorber includes a bottom rim, a top wall comprising a raised central portion and a top rim, a side wall extending between the top and bottom rims, and a corrugation surrounding a periphery of the raised central portion that (i) connects the raised central portion to the top rim, (ii) descends to a depth below half a height of the side wall, and (iii) is separated by a distance from a surface. Impact forces imparted on the shock absorber are attenuated by a first amount in a first stage by resistive yielding of the side wall; by a second amount in a second stage by depression of the central portion and resistive yielding of the corrugation associated therewith; and by a third amount in a third stage by resistive yielding of the corrugation in response to a force applied to the top rim upon contact with the surface.

What is claimed is: 
     
         1 . A shock absorber for attenuating impact forces imparted thereto in stages of differing attenuation, the shock absorber comprising:
 a top wall comprising a raised central portion and a top rim;   a bottom rim;   a side wall extending between the top and bottom rims; and   a corrugation surrounding a periphery of the raised central portion that (i) connects the raised central portion to the top rim, (ii) descends to a depth below half a height of the side wall, and (iii) is separated by a distance from a surface,   wherein the shock absorber is configured to attenuate impact forces imparted on the shock absorber by a first amount in a first stage by resistive yielding of the side wall, by a second amount in a second stage by depression of the central portion and resistive yielding of the corrugation associated therewith, and by a third amount in a third stage by resistive yielding of the corrugation.   
     
     
         2 . The shock absorber of  claim 1 , wherein the first amount is less than the second amount. 
     
     
         3 . The shock absorber of  claim 2 , wherein the second amount is less than the third amount. 
     
     
         4 . The shock absorber of  claim 1 , wherein the side wall comprises a first region having a first angle with respect to a vertical reference line and a second region having a second angle with respect to the vertical reference line, the second angle being different from the first angle. 
     
     
         5 . The shock absorber of  claim 4 , wherein the first angle and the second angle are acute angles, the first angle having a value less than that of the second angle, the first region being closer to the bottom rim than the second region. 
     
     
         6 . The shock absorber of  claim 4 , wherein the first region and the second region meet at a point disposed at approximately half the height of the side wall. 
     
     
         7 . The shock absorber of  claim 1 , wherein the shock absorber is configured to cause overlap in time between the first, second, and third stages. 
     
     
         8 . The shock absorber of  claim 1 , wherein the shock absorber is substantially cylindrically symmetric. 
     
     
         9 . The shock absorber of  claim 1 , wherein the bottom rim has a diameter equal to or greater than that of any portion of the side wall. 
     
     
         10 . The shock absorber of  claim 1 , wherein the corrugation is configured to yield in response to a force applied to the shock absorber when the top rim contacts the surface. 
     
     
         11 . A method for attenuating impact forces imparted to a shock absorber in stages of differing attenuation, the method comprising:
 attenuating the impact forces by a first amount in a first stage by resistive yielding of a side wall of the shock absorber, the side wall extending between a top rim and a bottom rim of the shock absorber;   attenuating the impact forces by a second amount in a second stage by depression of a raised central portion of the shock absorber and resistive yielding of a corrugation of the shock absorber associated therewith, the corrugation surrounding a periphery of the raised central portion, connecting the raised central portion to the top rim; and   attenuating the impact forces by a third amount in a third stage by resistive yielding of the corrugation in response to a force applied to the top rim upon contact with a surface initially separated by a distance from the corrugation.   
     
     
         12 . The method of  claim 11 , wherein the first amount is less than the second amount. 
     
     
         13 . The method of  claim 12 , wherein the second amount is less than the third amount. 
     
     
         14 . The method of  claim 11 , wherein the side wall comprises a first region having a first angle with respect to a vertical reference line and a second region having a second angle with respect to the vertical reference line, the second angle being different from the first angle. 
     
     
         15 . The method of  claim 14 , wherein the first angle and the second angle are acute angles, the first angle having a value less than that of the second angle, the first region being closer to the bottom rim than the second region. 
     
     
         16 . The method of  claim 14 , wherein the first region and the second region meet at a point disposed at approximately half a height of the side wall. 
     
     
         17 . The method of  claim 11 , wherein the occurrence of at least one of the first, second, and third stages overlaps the occurrence of another of the first, second, and third stages. 
     
     
         18 . The method of  claim 11 , wherein the bottom rim has a diameter equal to or greater than that of any portion of the side wall. 
     
     
         19 . The method of  claim 11 , wherein the shock absorber is substantially cylindrically symmetric. 
     
     
         20 . The method of  claim 11 , wherein the corrugation descends to a depth below half a height of the side wall.