Energy-absorbing element and related pretensioning flange

• US 9,133,899 B2
• Filed: 03/01/2011
• Issued: 09/15/2015
• Est. Priority Date: 03/01/2010
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Airbus Helicopters
• Inventors: Delage, Vincent, Sibottier, Catherine, Dhermand, Julien
• Primary Examiner(s): Momper, Anna
• Assistant Examiner(s): AUNG, SAN M
• Application Number:
  US13/581,339
• Publication Number:
  US 20130038007A1
• Time in Patent Office: 1,659 Days
• Field of Search: 267/179, 267/165, 267/160, 267/164, 267/145, 267/103, 267/158
• US Class Current: 1/1
• CPC Class Codes: F16F 1/13 comprising inserts and spacers between the windings for changing the mechanical or physical characteristics of the spring F16F1/122 takes precedence
• CPC Class Codes: F16F 2228/08 pre-stressed
• CPC Class Codes: F16F 2236/06 Tension
• CPC Class Codes: F16F 3/02 with springs made of steel or of other material having low internal friction

Abstract

The invention essentially relates to an energy-absorbing element (1′) comprising:

• • an absorbing portion (2),
  • a first (3) and second anchoring point (4),
  • a first (2′) and second (2″) distal ends of said absorbing portion (2) being respectively secured to the first and second anchoring points (3, 4),
  • characterized in that it also comprises:
  • a pretensioning flange (12) installed between the first (2′) and second (2″) distal ends, the length (L) of said flange (12) exceeding the gap (E) between the two distal ends (2′, 2″) in order to pretension said absorbing element.

Claims

1. An energy-absorbing element comprising:

an absorbing portion having two filiform elements oriented symmetrically about an axis of symmetry, each deformable filiform element having at least two successive straight segments connected by an arc-shaped segment;

a first and second anchoring point,

a first and second distal ends of the absorbing portion being respectively secured to the first and second anchoring points, and

a solid pre-tensioning rod installed between the first and second distal ends along the axis of symmetry, the length of the pre-tensioning rod maintains the absorbing portion in an extended position thereby elastically deforming the absorbing portion and defining a gap dimension between the two distal ends in order to pretension the energy absorbing element such that the gap dimension between the two distal ends when the energy-absorbing element is not pre-tensioned is less than the length of the pre-tensioning rod,

wherein the pre-tensioning rod is configured not to buckle under compressive forces exerted on the energy absorbing element and the pre-tensioning rod applies a tensile force to the absorbing portion equal to a predetermined threshold,

wherein the absorbing portion plastically deforms when the absorbing portion experiences tensile forces above the predetermined threshold.

2. The absorbing element according to claim 1, wherein the thickness of the rod is dependent on the compressive forces exerted by the absorbing portion on the rod to ensure the rod does not buckle.

3. The absorbing element according to claim 1, wherein pre-tensioning rod includes ends, each with two edges defining a basin for receiving the distal ends of the absorbing portion.

4. The absorbing element according to claim 1, wherein the absorbing portion is connected to the first and second distal ends thereby forming a single-piece continuous loop.

5. An energy absorbing element comprising:

first and second primary segments;

first and second anchor points fixedly secured to the first and second primary segments respectively; and

two energy absorbing portions oriented symmetrically about a longitudinal axis of symmetry and connecting the first and second primary segments in an elevation direction, each of the energy absorbing portions having a filiform shape formed by a plurality of straight-line segments each connected by an arcuate segment, the straight-line segments oriented at a pre-tensioned angle to one another;

a solid pre-tensioning rod inserted between the first and second primary segments along the axis of symmetry, wherein the length of the rod maintains the plurality of straight-line segments in an extended position thereby elastically deforming the energy absorbing portions to define the pre-tensioned angle,

wherein the pre-tensioning rod is configured not to buckle under compressive forces exerted on the energy absorbing element and the pre-tensioning rod applies a pretension force to the energy absorbing portions equal to a predetermined threshold,

wherein the energy absorbing portions deform plastically when a tensile force above the predetermined threshold is exerted on the first and second anchor points.

6. The absorbing element according to claim 5, wherein the two energy absorbing portions are connected to the first and second primary segments thereby forming a single-piece continuous loop.

7. The absorbing element according to claim 5 wherein the two energy absorbing portions are mirror images of each other and disposed symmetrically about the longitudinal axis of symmetry being parallel to the elevation direction.

8. The absorbing element according to claim 5, wherein pre-tensioning rod includes two basins for receiving each of the primary segments of the absorbing element.

9. An energy absorbing element comprising:

an energy absorber including;

first and second primary straight-line segments defining first and second distal ends of the energy absorber;

two energy absorbing connection portions oriented symmetrically about a longitudinal axis of symmetry and connecting the first and second primary segments in an elevation direction, each of the connection portions having an undulating filiform shape formed by a plurality of straight-line segments each connected by an arcuate segment, the straight-line segments oriented at a non-parallel pre-tensioned angle to one another and to the primary segments,

wherein the two energy absorbing portions are each connected to the first and second primary segments to define the energy absorber as a single-piece continuous loop;

first and second anchor points fixedly secured to the first and second distal ends respectively; and

a solid pre-tensioning rod inserted between the first and second primary straight line segments along the axis of symmetry, wherein the length of the rod extends and maintains the plurality of straight-line segments of the energy absorbing portions in an extended position thereby elastically deforming the energy absorbing portions to define the pre-tensioned angle,

wherein the pre-tensioning rod is configured not to buckle under compressive forces exerted on the energy absorbing element and the pre-tensioning rod applies a pretension force to the energy absorbing portions equal to a predetermined threshold,

wherein the energy absorber deforms plastically when a tensile force above the predetermined threshold is exerted on the first and second anchor points.

10. The absorbing element according to claim 9 wherein the two energy absorbing portions are mirror images of each other and disposed symmetrically about the longitudinal axis of symmetry being parallel to the elevation.

11. The absorbing element according to claim 9, wherein pre-tensioning rod includes two basins for receiving each of the primary segments of the energy absorber.