Crash dummy viscous neck

[57] ABSTRACT

A simulated neck construction and arrangement is provided for coupling a head structure to a torso structure of an anthropomorphic dummy of the type used in vehicular crash testing. The simulated neck construction and arrangement comprises a plurality of interconnected swivel units interposed between the head and torso structure. The swivel units permit fore and aft tilting movement, rotary movement about an axis lying in a vertical plane of the torso structure and substantially lateral tilting movement. A viscous damping means is housed within the swivel unit permitting fore and aft tilting movement to control the rate of deceleration of the head structure during such movements.

Claims, 4 Drawing Figures

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Patented Aug. 21, 1973

Sheets-Sheet 1

3,753,301

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Patented Aug. 21, 1973

Sheets-Sheet 2

3,753,301

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3,753,301

CRASH DUMMY VISCOUS NECK

BACKGROUND OF THE INVENTION

During crash testing of vehicles, anthropomorphic dummies, as disclosed in U.S. Pat. No. 3,557,471 issued Jan. 26, 1971, to P. R. Payne et al., are utilized in an attempt to analyze what might happen to a human occupant of the vehicle under similar conditions. The anthropomorphic dummies are articulated structures which provide for movement of the head and limbs relative to the torso. The neck structures currently available on most crash test dummies for supporting the head structure on the torso structure are so constructed and arranged that under crash conditions the head structure snaps violently backward or forward, creating excessive head decelerations not found in human biomechanic testing.

In U.S. application Ser. No. 259,093, filed June 2, 1972, in the name of R. J. Berton et al., entitled “Crash Dummy Viscous Neck,” there is disclosed a neck structure incorporating a hydraulic mechanism or control unit. The purpose of the viscous or hydraulic mechanism is to provide test results which will more nearly 25 approximate the results obtained from human biomechanical testing.

It is an object of the present invention to provide a crash dummy viscous neck structure utilizing a different form of viscous or hydraulic mechanism for controlling the rate of deceleration of the head structure and also to incorporate additional rotary and pivotal movements so that the movements of the dummy head during a crash test will more nearly simulate the movements of a human head under similar conditions.

SUMMARY OF THE INVENTION

DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will be made more apparent as this description proceeds, reference being had to the accompanying drawings, wherein:

FIG. 1 is a front view of an anthropomorphic dummy with a portion of the neck area surface removed in order to illustrate the environment in which the present invention is utilized;

FIG. 2 is a side elevation view also with a portion removed for clarity of illustration;

FIG. 3 is an enlarged vertical section through the vertically stacked swivel units; and

FIG. 4 is a section view on the line 4—4 of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, FIGS. 1 and 2 represent front and side views of an anthropomorphic dummy 11 of a type generally used in vehicle crash testing. The present invention is concerned with the interconnection between the head structure 12 and the upper torso structure 13 of the dummy. This interconnection takes the form of a swivel mechanism or control unit, generally designated 14, and shown in greater detail in FIGS. 3 and 4.

The swivel mechanism or control unit 14 comprises a plurality of swivel units 15, 16 and 17. The first unit 15 is supported on a bracket 18 the base 19 of which is adapted to be secured on the upper end 21 of the structure forming the spine and rib cage 22 of the dummy.

The bracket 18 has spaced upstanding legs 23. Each leg 23 has a square aperture 24 at its upper end which receives the square end 25 of a nonrotatable shaft 26. The shaft 26 is held in place by clamp screws 27, as best seen in FIG. 3.

This invention relates to a neck simulation device for coupling the head structure to a torso structure of an anthropomorphic dummy. The neck simulation device comprises a plurality of interconnected swivel units interposed between the torso structure and the head structure. A first one of the swivel units has pivot means positioned to provide for forward and backward tilting movements of the head structure about an axis substantially normal to the vertical axis of the torso structure. A viscous damping means is housed within this first one of the swivel units to control the rate of deceleration of the head structure during forward and rearward tilting movement. An intermediate one of the swivel units has pivot means supporting the head structure for pivotal movement about an axis normal to the first swivel unit axis. The axis normal to the first swivel unit axis lies in a vertical plane of the torso structure. A last one of the swivel units supports the head structure for tilting movement about an axis normal to the pivotal axis of the second swivel unit.

A damping means, preferably comprising a fluid filled chamber, is located within the first one of the swivel units. A braking member is relatively movable within the chamber. Orifice means in the braking member meters flow of fluid from one side of the braking member to the other side as the head structure undergoes tilting movements.

A housing 28 having a longitudinally extending chamber 29 extending therethrough is swingably journalled on bearings 31 carried on shoulder portions 32 of the shaft 26. The housing 28 is shown as a two-piece structure having a base section 33 and a cap portion 34 bolted thereon by bolts 35. Suitable sealing rings 36 and 37 are strategically placed to make the chamber 29 leakproof.

The chamber 29 is filled with a viscous fluid. A braking or paddle member 38 welded to the nonrotatable shaft 26 projects into the chamber 29, see FIG. 4. The ₅₀ braking or paddle member 38 has a pair of spaced threaded inserts 39 each having an aperture 41 extending from one end to the other. The apertures 41 are calibrated orifices the size of which may be changed by changing the inserts. The function of the orifices is to 5₅ regulate the flow of viscous fluid from one side to the other of the braking or paddle member 38. This fluid flow occurs as the housing swings about the pivot shaft 26, as will be explained.

The intermediate swivel unit 16 may be considered 60 as comprising a rectangular plate 42 bolted to the top of the housing 28. The plate 42 has an upstanding circular boss 43 which is a pilot for a friction washer 44 and a plate 45. The plate 45 is rectangular but has a circular recess 46 which fits over the friction washer 44. 65 The plate 45 is held in rotary relationship to the housing by a washer and bolt assembly 47.

Projecting upwardly from the plate 45 are a pair of spaced legs 48. Each leg 48 supports a pivot stud 49

3,753,301 which is threadedly engaged with threaded apertures 51 in spaced legs 52 depending from a plate 53. The plate 53 is the base plate of the swivel unit 17, as will be explained.

Interposed between each contiguous pair of legs 48 and 52 is a friction washer 54. Between the head of each pivot stud 49 and the adjacent surface of a leg 48 is a stack of Belleville washers 50. The pivot joint provided by the foregoing structure comprises a controllable friction joint by which the resistance of swiveling movement of the upper swivel unit 17 about the pivot studs 49 may be controlled.

In addition to the plate 53, the upper swivel unit 17 comprises a plate 55 separated from and bonded to the plate 53 by a rubber isolation material 56. The upper plate 55 is provided with a threaded bolt receiving hole 57 to which the frame structure 58 of the head structure 12 of the dummy is bolted. Because of the isolation material 56, there is no metal to metal contact between the head structure and torso structure of the dummy. 20

The swivel mechanism or control unit 14 embodying the present invention supports the head structure 12 on the torso structure 13 for movement about a plurality of axes. As described above, this is accomplished through the series of vertically stacked swivel units 15, 25 16 and 17. The base unit 15 permits the head structure to tilt about a substantially horizontal axis relative to the normal upright position of the torso structure. The tilting movement is in a forward and rearward direction about the axis of the pivot shaft 26. When a test vehicle ³⁰is subjected to a barrier crash test, the head 12 of the dummy is snapped violently backward or forward, creating excessive head decelerations not found during human biomechanics testing. As the swivel housing 15 swings about the shaft 26, the viscous fluid in the cham- ³⁵ber 29 acts to dampen the violent swinging movement of the head structure. The rate of deceleration is controlled by the flow of viscous fluid through the orifices 41 in the paddle member 38. It is thus possible to simulate to a greater degree of accuracy the reaction of the ⁴⁰human head under similar crash conditions.

There are, of course, other forces acting on the head structure during the decelerations resulting from the crash. There may be a force tending to twist the head structure about a vertical axis. The intermediate swivel ⁴⁵unit 16 provides for such twisting or rotary movement about the vertical axis. The swivel unit is mounted on the upper surface of the base swivel unit 15. Its resistance to rotary movement about the vertical axis defined by the pivot stud 47 is controlled by the friction washer 44 ans also by the amount of torque that has been placed on the pivot stud 47 in tightening the intermediate swivel unit base plate 16 to the plate 42 carried by the base swivel unit 15.

There also may be forces acting on the head structure tending to tilt the latter laterally or in a side to side swinging movement. This is accommodated by the upper swivel unit 17 which is supported on the pivot studs 49 which define a pivot axis that is normal to the vertical plane of the pivot axis of the stud 47. This pivot axis lies in a plane which is parallel to the plane of the axis defined by the shaft 26. Although in the “at rest” position shown in the drawing the pivot axis defined by the studs 49 is normal to the pivot axis defined by the shaft 26, it will be understood that this relationship may not be maintained as the intermediate swivel unit permits the head structure to rotate about the vertical axis

47. The pivot studs 49 provide a friction joint the resistance of which to lateral movement of the head structure may be controlled by the degree of tightness in the joint. That is, by tightening the bolts 49 the pressure on the Belleville washers 50 and the friction disk 54 may be increased or decreased as described thereby increasing or decreasing the frictional resistance of the swivel unit to lateral movement of the head structure 12.

It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the following claims: