METHOD AND APPARATUS FOR SIMULATING HEAD IMPACTS FOR HELMET TESTING

• US 20120247178A1
• Filed: 03/31/2011
• Published: 10/04/2012
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Fraser Worden Saunders, Martin William Ten Hove, Mihaly Kis Jr, Mihaly Kis Sr
• Original Assignee: Fraser Worden Saunders, Martin William Ten Hove, Mihaly Kis Jr, Mihaly Kis Sr
• Inventors: Kis, Mihaly Jr., Kis, Mihaly Sr., Saunders, Fraser Worden, ten Hove, Martin William
• Granted Patent: US 9,140,637 B2
• Time in Patent Office: Days
• US Class Current: 73/12.04
• CPC Class Codes: A42B 3/0433 Detecting, signalling or lighting devices
• CPC Class Codes: G01M 17/0078 Shock-testing of vehicles
• CPC Class Codes: G01N 2033/008 sport articles (balls, skis, rackets)
• CPC Class Codes: G01N 2033/0086 clothes; hosiery
• CPC Class Codes: G01N 3/30 by applying a single impulsive force, e.g. by falling weight

Abstract

An apparatus is disclosed that includes a frame, an impact delivery unit for delivering an impact force and at least one head form. The head form is adapted to be mounted to the frame such that the impact delivery unit can deliver an impact force to a designated location on the head form. The head form is configured to have a helmet installed thereon. The head form is selectively rotatable about each of a plurality of different axes of rotation, wherein movement of the head form is constrained to be able to move only in rotation and in rotation about only one axis of rotation of the plurality of axes at any time. A measuring system provides an indicator of the rotational acceleration of the head form when rotated about each of the plurality of axes. Also disclosed are methods for comparing the degree of protection afforded by first and second helmets.

Claims

1. An apparatus comprising:

a frame;

an impact delivery unit for delivering an impact force;

at least one head form adapted to be mounted to said frame such that said impact delivery unit can deliver an impact force to a designated location on said at least one head form;

said head form being configured to have a helmet installed thereon;

said at least one head form being selectively rotatable about each of a plurality of different axes of rotation, wherein movement of said at least one head form is constrained to be able to move only in rotation and in rotation about only one axis of rotation of said plurality of axes at any time;

a measuring system for providing an indicator of the rotational acceleration of said at least one head form when rotated about each of said plurality of axes;

wherein, when said impact delivery unit delivers a plurality of impact forces to said designated location on said at least one head form, such that said at least one head form rotates separately about each axis of rotation of said plurality of axes, and wherein said measurement system provides indicators of rotational accelerations about each of said plurality of axes of rotation of said at least one head form during separate rotations about each axis of said plurality of axes of rotation.

2. An apparatus as claimed in claim 1 wherein said at least one head form comprises a plurality of head forms and each of said plurality of head forms is rotatable only about a single respective axis of rotation of said plurality of axes of rotation, and wherein each of said plurality of head forms is adapted to be selectively mounted to said frame such that said impact delivery unit can respectively deliver an impact force to designated locations on each head form of said plurality of head forms and wherein when said impact delivery unit delivers an impact to said designated locations on said each head form, said each head form rotates about a selected single axis of rotation of said plurality of axes, and wherein said measurement system provides indicators of rotational acceleration about each of said plurality of axes of rotation during separate rotations of each of said plurality of head forms about each of said plurality of axes of rotation.

3. An apparatus as claimed in claim 2 wherein each of said plurality of head forms may be selectively configured on said frame for rotation about a different axis of rotation of said plurality of axes of rotation.

4. An apparatus as claimed in claim 2 wherein said impact force is a substantially constant impact force that can impact upon each of said plurality of head forms.

5. An apparatus as claimed in claim 1 wherein said at least one head form comprises a plurality of head forms each being adapted to be mounted to said frame such that said impact delivery unit can deliver an impact force to each said head form, and wherein each one of said plurality of head forms is adapted to be interchangeably mounted to said frame so as to be rotatable about a single respective axis of rotation of said plurality of different axes of rotation.

6. An apparatus as claimed in claim 2, wherein said measurement system comprises a measurement device associated with each of said plurality of head forms, each measurement device for measuring an acceleration of a different one of said plurality of head forms, wherein when said impact delivery unit delivers an impact to designated locations on each of said plurality of head forms, each said measurement device associated with each said head forms measures the acceleration of each said head form.

7. An apparatus as claimed in claim 1 wherein measurement system provides indicators of peak rotational accelerations about each of said plurality of axes of rotation.

8. An apparatus as claimed in claim 2 wherein measurement system provides indicators of peak rotational accelerations about each of said plurality of axes of rotation.

9. An apparatus as claimed in claim 6 wherein measurement system provides indicators of peak rotational accelerations about each of said plurality of axes of rotation.

10. An apparatus as claimed in claim 1 wherein said impact delivery unit comprises a piston device operable to impact a head form.

11. An apparatus as claimed in claim 10 wherein said impact delivery unit further comprises a piston assembly mounted to said frame, said piston assembly adapted to support said piston device.

12. An apparatus as claimed in claim 2 wherein said plurality of axes of rotation comprises a first axis of rotation and a second axis of rotation.

13. An apparatus as claimed in claim 12 wherein said plurality of axes of rotation further comprises a third axis of rotation.

14. An apparatus as claimed in claim 13 wherein said each of said first, second and third axes of rotation is associated with a respective one of a corresponding plurality of different planes of rotation, whereby said at least one head form is constrained to rotate in alignment with only one of said different planes of rotation at any time.

15. An apparatus as claimed in claim 14 wherein said plurality of planes of rotation comprise a sagittal plane through one of said plurality of head forms.

16. An apparatus as claimed in claim 15 wherein said plurality of planes of rotation further comprise a coronal plane through one of said plurality of head forms.

17. An apparatus as claimed in claim 8 wherein said plurality of head forms comprise first, second and third head forms, and wherein said plurality of different axes of rotation comprise first, second and third axes of rotation, said first axis being perpendicular to a sagittal plane, said second axis being perpendicular to a coronal plane, and said third axis being perpendicular to an axial plane, and wherein said first head form is rotatable only about said first axis, said second head form is rotatable only about said second axis, and said third head form is rotatable only about said third axis.

18. An apparatus of claim 1, wherein said at least one head form is adapted to have a helmet mounted thereon.

19. An apparatus as claimed in claim 2 wherein each of said plurality of head forms is adapted to receive a helmet.

20. An apparatus as claimed in claim 1, wherein said measurement system comprises a plurality of measuring devices each for measuring acceleration along a respective axis of rotation of said plurality of axes of rotation.

21. An apparatus as claimed in claim 2 wherein said measurement system comprises a separate measuring device for each of said plurality of head forms, each measuring device for measuring acceleration along a respective axis of rotation of said plurality of axes of rotation.

22. An apparatus as claimed in claim 21 wherein each said separate measuring device comprises an accelerometer for measuring an acceleration of said head form.

23. An apparatus as claimed in claim 19, wherein said impact delivery unit for delivering an impact force comprises a piston assembly having a piston operable to respectively impact said helmet when said helmet is received on said each head form at said designated locations.

24. An apparatus as claimed in claim 20 further comprising a positioning and support apparatus for adjusting the position in 3-D space of said piston relative to said helmet received on said each head form to thereby be able to adjust each point of impact of said plurality of points of impacts.

25. An apparatus as claimed in claim 24, wherein said positioning and support apparatus is operable to adjust said position of said piston in height, longitude and latitude of said piston relative to said helmet received on said each head form.

26. An apparatus as claimed in claim 25, further comprising a z-direction scale, an x-direction scale, and a y-direction scale for measuring height, longitude and latitude coordinates of said piston;

and a display adapted to display said height, longitude and latitude coordinates.

27. An apparatus as claimed in claim 1 further comprising a data device in communication with said measuring system for receiving and processing the indicator of the acceleration of said at least one head form when rotated about each of said plurality of axes to generate a rotational acceleration about each of said plurality of axes.

28. A method of testing a helmet, said method comprising:

providing an impact delivery unit having a force actuator for delivering an impact force;

providing at least one head form such that said impact delivery unit can deliver an impact force to said at least one head form;

impacting said at least one head form with said force actuator so as to rotate said at least one head form about a plurality of different axes of rotation in sequence, wherein movement of said at least one head form during each rotation is constrained to be able to move only in rotation and only about one axis of rotation of said plurality of axes at any time;

obtaining an indicator of each acceleration of said at least one head form when rotated about each of said plurality of axes;

from the indicators of acceleration, determining the rotational acceleration of each said head form during rotations about each of said plurality of axes of rotation.

29. A method as claimed in claim 29 wherein said indicators are indicators of peak rotational accelerations.

30. A method for testing a helmet, said method comprising:

selecting a first head form from a plurality of head forms, each of said plurality of head forms each being configured to rotate only about a different axis of rotation of a plurality of axes of rotation;

installing a helmet on said first head form;

exerting a force against said helmet at a designated location to thereby cause said selected head form to rotate about a first axis of rotation;

measuring an indicator of rotational acceleration about said first axis of rotation of said selected head form;

determining a rotational acceleration of said selected head form about said corresponding first axis of rotation;

selecting a second head form from a plurality of head forms;

installing said helmet on said second head form;

exerting a force against said helmet at a designated location to thereby cause said selected head form to rotate about said second axis of rotation;

measuring an indicator of rotational acceleration about said second axis of said selected head form;

determining a rotational acceleration of said selected head form about said second axis of rotation.

31. A method as claimed in claim 30 wherein said indicators are indicators of peak rotational accelerations.

32. A method as claimed in claim 30 further comprising:

selecting a third head form from a plurality of head forms;

installing said helmet on said third head form;

]

exerting a force against said helmet at a designated location to thereby cause said selected head form to rotate about said third axis of rotation;

measuring an indicator of rotational acceleration about said third axis of said selected head form;

determining a rotational acceleration of said selected head form about said third axis of rotation

33. A method as claimed in claim 32 wherein said indicators are indicators of peak rotational accelerations.

34. A method as claimed in claim 31 wherein each of said plurality of axes of rotation is associated with a different corresponding one of a plurality of planes of rotation

35. A method as claimed in claim 32 wherein said first, second and third axes of rotation are orthogonal to each other.

36. A method for testing a helmet, said method comprising:

i. selecting a head form adapted and constrained to rotate about a first axis of rotation of a plurality of axes of rotation;

ii. impacting the head form at a first designated location with a force actuator operable to exert a constant force against said head form to thereby cause said selected head form to rotate about said one axis of rotation;

iii. measuring an indicator of rotational acceleration in relation to said first axis of said head form;

iv. determining a baseline rotational acceleration in relation to said first axis of said head form;

v. installing a helmet on said head form;

vi. impacting the helmet installed on said head form at said first designated location with a force actuator operable to exert said constant force against said head form to thereby cause said selected head form to rotate about said one axis of rotation;

vii. measuring an indicator of rotational acceleration in relation to said first axis of said head form;

viii. determining a rotational acceleration of said selected head form when said helmet is installed on said head form; and

ix. determining a degree of protection against rotational acceleration in relation to said first axis afforded by the helmet for said impact point;

x. selecting a head form adapted and constrained to rotate about a second axis of rotation of a plurality of axes of rotation;

xi. impacting the head form at a second designated location with a force actuator operable to exert a constant force against said head form to thereby cause said selected head form to rotate about said second axis of rotation;

xii. measuring an indicator of rotational acceleration of said head form;

xiii. determining a baseline rotational acceleration in relation to said second axis of said head form;

xiv. installing said helmet on said head form;

xv. impacting the helmet installed on said head form at said second designated location with a force actuator operable to exert said constant force against said head form to thereby cause said selected head form to rotate about said one axis of rotation;

xvi. measuring an indictor of rotational acceleration in relation to said second axis of said head form;

xvii. determining a rotational acceleration in relation to said second axis of said selected head form when said helmet is installed on said head form; and

xviii. determining a degree of protection against rotational acceleration in relation to said second axis afforded by the helmet for said impact point.

37. A method as claimed in claim 36 wherein said indicators are indicators of peak rotational accelerations.

38. A method as claimed in claim 36 further comprising:

a. selecting a head form adapted and constrained to rotate about a third axis of rotation of a plurality of axes of rotation;

b. impacting the head form at a third designated location with a force actuator operable to exert a constant force against said head form to thereby cause said selected head form to rotate about said third axis of rotation;

c. measuring an indictor of rotational acceleration of said head form;

d. determining a baseline rotational acceleration in relation to said third axis of said head form;

e. installing a helmet on said head form;

f. impacting the helmet installed on said head form at said third designated location with a force actuator operable to exert said constant force against said head form to thereby cause said selected head form to rotate about said third axis of rotation;

g. measuring an indictor of rotational acceleration of said head form;

h. determining a rotational acceleration in relation to said third axis of said selected head form when said helmet is installed on said head form; and

i. determining a degree of protection against rotational acceleration in relation to said third axis afforded by the helmet for said impact point.

39. A method as claimed in claim 38 wherein said indicators are indicators of peak rotational accelerations.

40. A method as claimed in claim 38 further wherein said first, second and third axes are orthogonal to each other.

41. A method as claimed in claim 38 wherein each of said first, second and third axes are orthogonal to a different one of a sagittal plane, a coronal plane and an axial plane of said head from.

42. A method as claimed in claim 36 wherein said head from is impacted multiple times at said designated location such that steps ii and iii and are repeated said multiple of times to generate the baseline rotational acceleration in relation to said first axis.

43. A method as claimed in claim 42 further comprising obtaining an acceptable degree of variance in the baseline rotational acceleration in relation to the first axis.

44. A method as claimed in claim 43 wherein said head from is impacted multiple times at said designated location such that steps xi and xii are repeated said multiple of times to generate the baseline rotational acceleration in relation to said second axis.

45. A method as claimed in claim 44 further comprising obtaining an acceptable degree of variance in the baseline rotational acceleration in relation to the second axis.

46. A method as claimed in claim 45 wherein with said helmet installed on said head form, said helmet installed on said head from is impacted multiple times such that steps vi, vii and viii are repeated multiple times to determine the degree of protection against rotational acceleration in relation to said first axis.

47. A method as claimed in claim 46 wherein with said helmet installed on said head form, said helmet installed on said head from is impacted multiple times such that steps xv, xvi and xvii are repeated multiple times to determine the degree of protection against rotational acceleration in relation to said second axis.

48. A method as claimed in claim 47 wherein said indicators are indicators of peak rotational accelerations.

49. A method as claimed in claim 47 wherein mean acceleration measurements for both baseline accelerations and helmet attached head form accelerations in relation to said first axis are compared to determine said degree of protection in relation to said first axis.

50. A method as claimed in claim 49 wherein mean acceleration measurements for from both baseline accelerations and helmet attached head form accelerations in relation to said second axis are compared to determine said degree of protection in relation to said second axis.

51. A method as claimed in claim 37 wherein said head from is impacted multiple times at said designated location such that steps ii and iii and are repeated said multiple of times to generate the baseline rotational acceleration in relation to said first axis.

52. A method as claimed in claim 51 further comprising obtaining an acceptable degree of variance in the baseline rotational acceleration in relation to the first axis.

53. A method as claimed in claim 52 wherein said head from is impacted multiple times at said designated location such that steps xi and xii are repeated said multiple of times to generate the baseline rotational acceleration in relation to said second axis.

54. A method as claimed in claim 53 further comprising obtaining an acceptable degree of variance in the baseline rotational acceleration in relation to the second axis.

55. A method as claimed in claim 54 wherein with said helmet installed on said head form, said helmet installed on said head from is impacted multiple times such that steps vi, vii and viii are repeated multiple times to determine the degree of protection against rotational acceleration in relation to said first axis.

56. A method as claimed in claim 55 wherein with said helmet installed on said head form, said helmet installed on said head from is impacted multiple times such that steps xv, xvi and xvii are repeated multiple times to determine the degree of protection against rotational acceleration in relation to said second axis.

57. A method as claimed in claim 56 wherein said head from is impacted multiple times at said designated location such that steps b and c and are repeated said multiple of times to generate the baseline rotational acceleration in relation to said third axis.

58. A method as claimed in claim 42 further comprising obtaining an acceptable degree of variance in the baseline rotational acceleration in relation to the third axis.

59. A method as claimed in claim 45 wherein with said helmet installed on said head form, said helmet installed on said head from is impacted multiple times such that steps f, g and h are repeated multiple times to determine the degree of protection against rotational acceleration in relation to said third axis.

60. A method as claimed in claim 59 wherein said indicators are indicators of peak rotational accelerations.

61. A method as claimed in claim 55 wherein mean acceleration measurements for from both baseline accelerations and helmet attached head form accelerations in relation to said first axis are compared to determine said degree of protection in relation to said first axis.

62. A method as claimed in claim 56 wherein mean acceleration measurements for from both baseline accelerations and helmet attached head form accelerations in relation to said second axis are compared to determine said degree of protection in relation to said second axis.

64. A method as claimed in claim 49 further comprising

generating a baseline rotational acceleration in relation to said third axis of said head form;

generating a rotational acceleration in relation to said third axis when said helmet is installed on said head form; and

determining a degree of protection against rotational acceleration in relation to said second axis afforded by the helmet.

63. A method for testing a helmet, said method comprising:

providing a head form adapted and constrained to rotate separately about a first axis of rotation and a second axis of rotation;

generating a baseline rotational acceleration in relation to said first axis of said head form;

generating a rotational acceleration in relation to said first axis when said helmet is installed on said head form;

determining a degree of protection against rotational acceleration in relation to said first axis afforded by the helmet;

generating a baseline rotational acceleration in relation to said second axis of said head form;

generating a rotational acceleration in relation to said second axis when said helmet is installed on said head form; and

determining a degree of protection against rotational acceleration in relation to said second axis afforded by the helmet.

65. A method for comparing first and second helmets, said method comprising:

providing a head form adapted and constrained to rotate separately about a first axis of rotation and a second axis of rotation;

generating a rotational acceleration in relation to said first axis when said first helmet is installed on said head form;

generating a rotational acceleration in relation to said first axis when said second helmet is installed on said head form;

comparing the rotational acceleration in relation to said first axis and the second axis between when the first and second helmets are installed on the head form.

66. A method for comparing first and second helmets, said method comprising:

i. selecting a first head form adapted and constrained to rotate about a first axis of rotation of a plurality of axes of rotation;

ii. installing a first helmet on said first head form;

iii. exerting a first force on said first helmet installed on said first head form at a first designated location to thereby cause said first head form to rotate about said first axis of rotation;

iv. measuring an indicator of rotational acceleration in relation to said first axis of said first head form;

v. determining a rotational acceleration in relation to said first axis of said first head form when said first helmet is installed on said first head form; and

vi. installing a second helmet on said first head form;

vii. exerting said first force on said second helmet installed on said first head form at said first designated location to thereby cause said first head form to rotate about said second axis of rotation;

viii. measuring an indicator of rotational acceleration in relation to said second axis of said first head form;

ix. determining a rotational acceleration in relation to said second axis of said first head form when said second helmet is installed on said first head form; and

x. comparing the rotational accelerations in relation to said first axis between said first and second helmets;

xi. selecting a second head form adapted and constrained to rotate about a second axis of rotation of a plurality of axes of rotation;

xii. installing said first helmet on said second head form;

xiii. exerting a second force on said first helmet installed on said second head form at a second designated location to thereby cause said second head form to rotate about said second axis of rotation;

xiv. measuring an indicator of rotational acceleration in relation to said second axis of said second head form;

xv. determining a rotational acceleration in relation to said second axis of said second head form when said first helmet is installed on said second head form;

xvi. installing a second helmet on said second head form;

xvii. exerting said force on said second helmet installed on said second head form at said second location to thereby cause said second head form to rotate about said second axis of rotation;

xviii. measuring an indicator of rotational acceleration in relation to said second axis of said second head form;

xix. determining a rotational acceleration in relation to said second axis of said second head form when said second helmet is installed on said head form;

xx. comparing the rotational accelerations in relation to said first axis between said first and second helmets.

67. An apparatus comprising:

at least one head form;

a helmet configured for attachment to said at least one head form;

an impact delivery unit for delivering an impact force to said helmet at at least one designated location when said helmet is attached to said at least one head form;

said at least one head form being selectively rotatable about a plurality of different axes of rotation, wherein movement of said at least one head form is constrained to be able to move only in rotation and only in rotation about one axis of rotation of said plurality of axes at any time;

a measuring system for providing an indicator of the acceleration of said at least one head form when rotated about each of said plurality of axes;

wherein when said impact delivery unit delivers an impact to said at least one head form, said measurement device associated with each said head from measures the acceleration of each said head form during rotations about each of said plurality of axes of rotation.