2. Background Art Door beams have long been used to prevent injury in the event of side impact collisions in certain vehicles. Side impact collisions are quite common on today's roads, and, many injuries are the result of side impact collisions.

Side door beams are generally mounted between the door skin and the inner door padding and are designed to absorb energy in an accident, to prevent the collapse of the door into the passenger compartment. Indeed, Federal Guidelines have been imposed relative to the strength and the performance of side door beams.

Current door beams that are installed in passenger vehicles comprise two or more brackets and a center tube that is formed through extrusion, or other process. The center tube is supported by the brackets, which, in turn, are welded to the door itself. Such door beams generally are of a steel material and, as a result are quite heavy. The added weight of such door beams, especially on a four door vehicle or on a full size vehicle, is substantial.

Attempts to use lighter materials, such as aluminum, have been less than satisfactory. These lighter materials have not been able to sufficiently withstand side impact collisions. Specifically, during impact, some door beams composed of these lighter materials have been too ductile, and the door beams deform without absorbing adequate impact energy. Other failures have resulted from the use of materials that are too brittle, and are subject to splitting. Splitting of side door beams is quite dangerous as sharp objects can be introduced into the passenger cabin.

SUMMARY OF THE INVENTION A safety door beam for use in association with a vehicle door comprises means for absorbing and controllably dissipating impact forces imparted to a vehicle door, and, means for attachment of the frame member to the vehicle door. The absorbing means comprises a frame member that includes a base region and at least one extremity region extending from the base region.

in a preferred embodiment, the base region of the frame member is curved between a first and a second end thereof. In such a preferred embodiment, the curve may be substantially uniformly sinusoidal.

In a preferred embodiment, the absorbing and dissipating means further includes at least one member associated with the extremity region. In such a preferred embodiment, the at least one extremity region comprises two extremity regions. The first extremity region is associated with a top end of the base region . The second extremity region is associated with a bottom end of the base region. Preferably, each of the extremity regions are positioned in parallel and substantially perpendicular to the base region.

Further, in such an embodiment, the at least one member is attached to each of the extremity regions, to, in turn, maintain the extremity regions at a predetermined orientation relative to each other. Preferably, the at least one member comprises a tube member. In a preferred embodiment, the at least one member includes a reinforcement member. In such an embodiment, the reinforcement member comprises at least one additional tube member positioned coaxially to the tube member.

In another preferred embodiment, the attachment means comprises a bracket member associated with the frame member and the vehicle door.

In a preferred embodiment, the safety door beam further includes means for controlled fracturing of the frame member. This serves to fracture portions of the frame member in a controlled manner, which, in turn, further absorbs impact energy in a controlled manner. In such a preferred embodiment, the controlled fracture means comprises at least one pop tab region positioned on one of the base region and the extremity region of the frame member.

In a preferred embodiment the frame member comprises an aluminum material. In another preferred embodiment, the frame member comprises a single extrusion.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 of the drawings is a top plan view of the safety door beam according to the present invention; Fig. 2 of the drawings is a cross sectional view of the safety door beam taken generally along lines 2-2 of Fig. 1; and Fig. 3 of the drawings is a partial schematic cross sectional view of the safety door beam taken generally along lines 3-3 of Fig. 1.

DETAILED DESCRIPTION OF THE DRAWINGS While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail, one specific embodiment with the understanding that the present disclosure can be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.

Safety door beam 10 is shown in Figs. 1 and 3 as comprising means 13 for absorbing and controllably dissipating impact forces imparted to a vehicle door, means 75 for controlling the fracturing of the frame member (Fig. 1) and means 1 4 for attachment to a vehicle door. Absorbing and dissipating means 1 3 includes frame member 1 2 and at least one member for maintaining an orientation of the frame member. Frame member 1 2 includes base region 1 6 and at least one extremity region, such as extremity region 1 8. Preferably, frame member 12 is stamped as a single piece of material. Of course, other forms of construction are likewise contemplated. Additionally, while other materials are contemplated, the frame member comprises aluminum alloy 5083- H321 having a thickness of either .118 inches or .138 inches.

Base region 16, as shown in Figs. 1 and 3, comprises first end 80, second end 82, top end 84 and bottom end 86. Base region includes a curved surface extending at least partially between first end 80 and second end 82.

For example, the curved surface may comprise a sinusoidal curved surface, however various other configurations are contemplated. As will be explained, the curved surface facilitates greater deformation of the safety door beam inasmuch as the effective length of the base region along the curve is greater than the distance between the first and second end thereof.

Extremity regions 18, 18' are shown in Figs. 1 through 3. Extremity region 1 8 extends from top end 84 and follows the curved contours of the base region from the first end to the second end thereof. Likewise, extremity region 18' extends from bottom end 86 of the base region. The extremity regions are generally perpendicular to the base region and parallel to each other. Thus, as shown in Fig. 2, the extremity regions and the base region

define a substantially c-shaped channel. Of course, multiple extremity regions, as well as a single extremity region, are contemplated. Additionally, while the extremity regions are shown to be simiiar in configuration, it is likewise contemplated that there may be variations in thickness, and relative sizing of the extremity regions.

The at least one member for maintaining the proper orientation is shown in Fig. 3 as comprising openings 29, 29', inner tube member 30, rigidifying member 31 and lip members 70, 70'. Openings 29, 29' extend through each of extremity regions 18, 18', respectively. The two openings are positioned collinearly and share a common central axis. While openings 29, 29' are shown to be of a circular configuration, other shapes (depending on the shape of the inner tube member) are likewise contemplated.

Inner tube member 30 is shown in Fig. 3 as extending through both of openings 29, 29'. At either end thereof, inner tube member includes means 90 for attaching inner tube member 30 to openings 29, 29', to, in turn, maintain the inner tube in rigid attachment with the frame member proximate the two openings. Attachment means 90 comprises the formation of crimp regions on the inner tube member proximate openings 29, 29'. Such a crimp can be formed through various means, including retrogression heat treatment and subsequent forging, among other methods. While other materials are contemplated, inner tube member 30 comprises aluminum alloy 6061-T4.

Additionally, other attachment means such as welding the inner tube member to the extremity regions is likewise contemplated.

Rigidifying member 31 is shown in Figs. 1 and 2 as comprising outer tube 32. Outer tube 32 extends between extremity regions 18, 18' and around inner tube 30. Outer tube 32 rigidifies the inner tube member to, in turn, prevent the deformation, and, in turn, disengagement of the inner tube from the extremity regions during an impact. Of course, while only one outer tube is shown, the use of several coaxial tubes as well as other rigidifying members is likewise contemplated. Likewise, it is contemplated that in certain applications the use of rigidifying members is not needed.

Additionally, it will be understood that while both inner tube 30 and outer tube 32 are shown to be circular, many other configurations, both those that are uniform and as well as those that are non-uniform are likewise contemplated. Additionally, while a hollow tube is contemplated other hollow, partially hollow or solid configurations are likewise contemplated.

Lip member 70, 70' is shown in Fig. 3 as comprising an upturned outer edge of extremity regions 18, 18'. The lip member increases the rigidity of the respective extremity region, and contributes to extremity region's resistance to buckling during an impact. While lip member comprises an upturned edge, it is likewise contemplated that the lip member may comprise an inwardly turned or flanged edge as well as separate member that is attached to the outer edge of the respective extremity region.

Controlled fracture means 75 is shown in Figs. 1 and 2 as comprising pop tab regions such as pop tab region 26 and channels such as channel 34 both of which are associated with extremity region 18. As will be explained, pop tabs are designed to fracture about channel 34, thereby absorbing energy from an applied load. While shown on extremity region 18, the pop tabs may be positioned on any one of the extremity regions and/or the base region.

Indeed, the particular locations of and the overall quantity of pop tabs as well as the configuration of the channel itself can be determined for each particular application.

Attachment means 14 as shown in Fig. 1 comprises brackets 22, 22' and fasteners such as fasteners 24. Brackets 22, 22' are positioned at either end of frame 1 2. The brackets are attached to the door panels through fasteners 24, 24', respectively. Of course, brackets can be of various lengths, materials and design styles to accommodate individual vehicles. Additionally, other attachment means, such as welding, interference fits, adhesion, among others, are likewise contemplated for use.

In operation, the safety door beam comprises a passive safety feature found within the door panels of the vehicle. During a collision, the safety door beam is design to absorb energy, and to controllably deform to, in turn, prevent

injury to occupants in the vehicle. As the impact occurs, the frame member begins to deform. Specifically, the curved base region begins to straighten and stretch, which, in turn, begins to both deform and stretch each of the extremity regions. As these regions continue to stretch, and, absorb energy from the impact, the channel regions expand and break, and, in turn, at least partially dislodge each of pop tab regions 26. As explained above, the controlled popping of these regions additionally absorb and dissipates impact energy.

As further deformation occurs, integrity maintaining means serves to maintain the relative orientation of the base region and the extremity regions so that the c-shaped channel of the frame member is retained to the extent possibie. Specifically, the greatest absorption of energy occurs when the extremity regions are retained substantially perpendicular to the base region, and the tube members specifically maintain the two extremity regions in such a desired orientation.

Through the foregoing structure, safety door beam 10 is capable of deflecting to a great extent without breaking. Indeed, certain prototypes have during testing deflected up to 14 inches without breaking. Thus, a substantial amount of energy is absorbed by the safety door beam during controlled deformation, while preventing penetration of outside material into the passenger cabin. As such, maximum safety, and, in turn, minimization of injury to the occupants, can be achieved.

The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto, as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.