Kinetic energy absorbing pad

• US 4,227,593 A
• Filed: 11/25/1977
• Issued: 10/14/1980
• Est. Priority Date: 10/04/1976
• Status: Expired due to Term

• Current Assignee: Centria, Inc. (Cornerstone Building Brands, Inc.)
• Original Assignee: H.H. Robertson Co. (Cornerstone Building Brands, Inc.)
• Inventors: Ting, Raymond M. L., Bricmont, Robert J., Hamilton, Philip A.
• Primary Examiner(s): Kazenske, Edward R.
• Application Number:
  US05/855,074
• Time in Patent Office: 1,054 Days
• Field of Search: 188/1 C, 293/70, 293/71 R, 293/97, 293/98, 293/99, 293/DIG. 3, 293/133, 428/73, 428/116, 52/167, 52/662, 49/9, 256/13.1
• US Class Current: 188/377
• CPC Class Codes: F16F 7/121 the members having a cellular, e.g. honeycomb, structure
• CPC Class Codes: F16L 55/005 Devices restraining ruptured tubes from whipping
• CPC Class Codes: G21D 1/02 Arrangements of auxiliary equipment
• CPC Class Codes: Y02E 30/00 Energy generation of nuclear origin
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A pad adapted to sustain an impact load by stepwise absorption of kinetic energy. The pad incorporates a collapsible, i.e., crushable core adapted to undergo stepwise deformation under the force of the impact load. Stepwise deformation of the core provides, during impact load application, a significant lowering of the peak dynamic load sustained by the pad and applied to the pad support. The normally encountered high buckle-initiating peak loads are entirely avoided by the present pad.

Claims

1. An energy absorbing pad providing stepwise absorption of the kinetic energy of an impact load, comprising:

a face plate adapted to be positioned transversely of and in confronting relation with said impact load;

a base plate spaced-apart from and substantially parallel with said face plate; and

a crushable core positioned between said face plate and said base plate and adapted to buckle under the force of said impact load, said core including a first set and a second set of profiled sheet metal elements having corrugations normal to said face plate, said profiled sheet metal elements being assembled in pairs, each of said pairs constituting a metal cellular unit which buckles independently of each other said unit under the force of said impact load,

the elements of said first set and of said second set presenting first end faces adjacent to one said plate and residing substantially in a first common plane which extends generally parallel with said one said plate,

the elements of said first set presenting second end faces adjacent to the other said plate and residing substantially in a second common plane which extends generally parallel with said other said plate, and

the elements of said second set presenting third end faces spaced-apart from said other said plate and residing substantially in a third common plane which extends between and is generally parallel with the first and second common planes,

the distance between the second and third end faces ranging from a minimum of 0.25 inch to a maximum of 0.75 inch;

said face plate being adapted to distribute the force of said impact load initially to said first set of said profiled elements through the first and second end faces thereof, and subsequently and simultaneously to said second set of said profiled elements through the first and third end faces thereof and to said first set of profiled elements, thereby to initiate axial buckling of said second set of profiled elements after initiation of the axial buckling of said first set of profiled elements thereby to significantly lower the dynamic peak loads sustained by said pad and said base plate without significantly reducing the energy absorbing capacity of said pad.

2. The pad of claim 1 wherein the second and third end faces are provided by separate ones of said profiled sheet metal elements.

3. The pad of claim 1 wherein the second and third end faces are provided by separate ones of said metal cellular units.

4. The pad of claim 1 wherein the thickness of the profiled sheet metal elements of said second set is less than that of the profiled sheet metal elements of said first set.

5. The pad of claim 1 wherein the second and third end faces are alternately presented.

6. The pad of claim 1 wherein the profiled elements provided on opposite sides of said crushable core present said second end faces.

7. In combination, a source of anticipated dynamic impact loads, a structure confronting said source of anticipated dynamic impact loads and a pad interposed between said structure and said source and adapted to sustain dynamic impact loads from said source by stepwise absorption of the kinetic energy of said dynamic impact loads, said pad comprising:

a base plate adjacent to said structure;

a face plate confronting said source and extending substantially parallel with said base plate; and

a crushable core positioned between said face plate and said base plate and adapted to buckle under the force of said dynamic impact loads, said core including a first set and a second set of profiled sheet metal elements having corrugations normal to said face plate, said profiled sheet metal elements being assembled in pairs, each of said pairs constituting a metal cellular unit which buckles independently of each other said unit under the force of said dynamic impact loads,

the elements of said first set and of said second set presenting first end faces adjacent to one said plate and residing substantially in a first common plane which extends generally parallel with said one said plate,

the elements of said first set presenting second end faces adjacent to the other said plate and residing substantially in a second common plane which extends generally parallel with said other said plate, and

the elements of said second set presenting third end faces spaced-apart from said other said plate and residing substantially in a third common plane which extends between and is generally parallel with the first and second common planes,

the distance between the second and third end faces ranging from a minimum of 0.25 inch to a maximum of 0.75 inch;

said face plate being adapted to distribute the force of said dynamic impact loads initially to said first set of said profiled elements through the first and second end faces thereof, and subsequently and simultaneously to said second set of said profiled elements through the first and third end faces thereof and to said first set of profiled elements, thereby to initiate axial buckling of said second set of profiled elements after initiation of the axial buckling of said first set of profiled elements thereby to significantly lower the dynamic peak loads sustained by said pad and said base plate without significantly reducing the energy absorbing capacity of said pad.

8. The combination of claim 7 wherein the second and third end faces are provided by separate ones of said profiled sheet metal elements.

9. The combination of claim 7 wherein the second and third end faces are provided by separate ones of said metal cellular units.

10. A crushable core adapted for stepwise absorption of the kinetic energy of an impact load, said core comprising:

profiled sheet metal elements assembled in pairs, each of said pairs constituting a metal cellular unit which undergoes axial buckling independently of each other said unit under the force of said impact load;

a first set of said elements having a first axial length;

a second set of said elements having a second axial length which is less than the said first axial length;

the difference between said first axial length and said second axial length ranging from a minimum of 0.25 inch to a maximum of 0.75 inch;

the elements of said first set and of said second set presenting first end faces residing substantially in a first common plane extending normal to the axial length of said elements;

the elements of said first set having opposite second end faces residing substantially in a second common plane generally parallel with said first common plane;

the elements of said second set having opposite third end faces residing substantially in a third common plane positioned between and extending generally parallel with said first common plane and said second common plane;

whereby axial buckling of said second set of profiled elements will be initiated after initiation of the axial buckling of said first set of profiled elements thereby to significantly reduce the dynamic peak loads sustained by said core without significantly reducing the energy absorbing capacity of said core.

11. The crushable core of claim 10 wherein the second and third end faces are provided by separate ones of said profiled sheet metal elements.

12. The crushable core of claim 10 wherein the second and third end faces are provided by separate ones of said metal cellular units.

13. The crushable core of claim 10 wherein the thickness of the elements of said second set is less than that of the elements of said first set.

14. The crushable core of claim 10 wherein the second and third end faces are alternately presented.

15. The crushable core of claim 10 wherein the elements positioned on the opposite sides of said crushable core are of said first axial length.