Dynamic load-absorbing materials and articles

• US 9,839,250 B2
• Filed: 03/06/2013
• Issued: 12/12/2017
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Original Assignee: Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Inventors: Nauman, Eric, Breedlove, Evan Louis, Zakrajsek, Anne Dye, Talavage, Thomas Michael
• Primary Examiner(s): Hurley, Shaun R
• Assistant Examiner(s): Sutton, Andrew W
• Application Number:
  US13/787,749
• Publication Number:
  US 20140068840A1
• Time in Patent Office: 1,742 Days
• CPC Class Codes: A42B 3/06 Impact-absorbing shells, e.g. of crash helmets
• CPC Class Codes: A42B 3/064 with relative movement between layers
• CPC Class Codes: A42B 3/128 with zones of different density
• CPC Class Codes: A43B 13/188 Differential cushioning regions
• CPC Class Codes: A61G 5/1045 for the seat portion
• CPC Class Codes: A61G 7/05715 with modular blocks, or inserts, with layers of different material
• CPC Class Codes: A61G 7/05723 with cut-outs or depressions in order to relieve the pressure on a part of the body mattresses with cavities A47C27/142

Abstract

A double-shell helmet is disclosed. The double-shell helmet includes an outer shell, an impact absorbing material layer affixed to the outer shell on a first side of the impact absorbing material layer, an inner shell affixed to the impact absorbing material layer on a second side of the impact absorbing material layer opposite the first side of the impact absorbing material layer, and a foam layer affixed to the inner shell.

Claims

1. A double-shell helmet, comprising:

an outer shell;

an impact absorbing material layer affixed to the outer shell on a first side of the impact absorbing material layer, the impact absorbing material layer including

a matrix material including at least three sizes of stress-concentrating features and further including;

a plurality of first features having a first average characteristic dimension of between ten microns and two hundred microns,

a plurality of second features having a second average characteristic dimension that is at least one order of magnitude larger than said first average characteristic dimension, and

a plurality of third features having a third average characteristic dimension that is at least one order of magnitude larger than said second average characteristic dimension,

wherein the material proximate to said first, second, and third features progressively buckles upon application of a load, such that material proximate said third features tends to deform before the deformation of material proximate to said second and first features, and material proximate said first features tends to deform after the deformation of material proximate to said second and third features;

an inner shell affixed to the impact absorbing material layer on a second side of the impact absorbing material layer opposite the first side of the impact absorbing material layer; and

a foam layer affixed to the inner shell.

2. The double-shell helmet of claim 1, the outer shell is composite.

3. The double-shell helmet of claim 1, the inner shell is composite.

4. The double-shell helmet of claim 1, further comprising:

at least one link member connecting the outer shell to the inner shell.

5. The double-shell helmet of claim 4, the at least one link member provides a non-linear force-displacement profile.

6. The double-shell helmet of claim 5, the at least one link member is longer than a distance defined by spacing between the outer shell and the inner shell.

7. The double-shell helmet of claim 1, the impact absorbing material layer configured to substantially absorb rotational energy between the outer shell and the inner shell.