Abstract:
A bumper bar construction, as for use with automobiles to absorb collision impact energies, has a closed trapezoidal cross-sectional shape. The bumper bar construction includes a broad flange on one broad side of the trapezium and a narrow flange on the opposite, narrow side of the trapezium. The broad and narrow flanges extend generally in mutually parallel planes. The bumper bar construction further includes two mutually convergent webs which join the two flanges together.

Description:
CONTINUING APPLICATION DATA 
     This application is a continuation-in-part of International Patent Application No. PCT/SE95/00054 filed on Jan. 20, 1995 and published on Aug. 3, 1995, which claims priority from Swedish Patent Application No. 9400227-6 filed on Jan. 26, 1994. International Patent Application No. PCT/SE95/00054 was pending as of the filing date of this application and designated the United States of America as a designated state. 
    
    
     CONTINUING APPLICATION DATA 
     This application is a continuation-in-part of International Patent Application No. PCT/SE95/00054 filed on Jan. 20, 1995 and published on Aug. 3, 1995, which claims priority from Swedish Patent Application No. 9400227-6 filed on Jan. 26, 1994. International Patent Application No. PCT/SE95/00054 was pending as of the filing date of this application and designated the United States of America as a designated state. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a bumper bar construction which is primarily intended for use with automobiles to absorb collision impact energies, although it will be understood that the use of the inventive bumper bar construction is not limited to automobiles, but can be used in all cases in which impact energy is to be absorbed by deformation of the bumper bar. 
     2. Background of the Invention 
     The inventive bumper bar construction has a closed trapezoidal cross-sectional shape and includes a broad flange on one broad side of the trapezium and a narrow flange on the opposite narrow side of the trapezium, said broad and said narrow flanges extending generally in mutually parallel planes, and further includes two mutually convergent webs which join the two flanges together. 
     OBJECT OF THE INVENTION 
     The object of the present invention is to provide a bumper bar construction of the type defined in the introduction which when subjected to impact will absorb impact energy by controlled deformation of the bumper bar up to the point at which the bar possibly collapses. 
     SUMMARY OF THE INVENTION 
     The inventive bumper bar construction is characterized in that the respective webs of the trapezium cross-section have at least one bend guide, such as a fold, which extends along the bumper bar, and in that a part of the web that is located proximal to the broad web on the bar is bent outwards from the centre line of said bar. The bumper bar is intended to be mounted on either end of e.g. an automobile, with the aid of fastener means attached to one of the two flanges. When the bumper bar is subjected to a force which acts at right angles to the flanges, the bend guides function to cause the webs of the bumper bar to bend successively towards the broad flange. The webs will continue to bend and to absorb energy until the two flanges are contiguous with one another. If the force continues to act on the bumper, the flanges will thereafter deform and the bumper beam will totally collapse. 
     The bend guide in respective webs will preferably have the form of a sharp fold, although it may also have other forms of course. 
     Further details and characteristic features of the inventive bumper bar construction will be apparent from the following claims and also from the following description made with reference to the accompanying drawings. 
     The above discussed embodiments of the present invention will be described further hereinbelow with reference to the accompanying figures. When the word &#34;invention&#34; is used in this specification, the word &#34;invention&#34; includes &#34;inventions&#34;, that is, the plural of &#34;invention&#34;. By stating &#34;invention&#34;, the Applicant does not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintains that this application may include more than one patentably and non-obviously distinct invention. The Applicant hereby asserts that the disclosure of this application may include more than one invention, and, in the event that there is more than one invention, that these inventions may be patentable and non-obvious one with respect to the other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is in the following disclosed in the form of embodiments with reference to the accompanying drawings. 
     FIG. 1A is a cross-sectional view of a first embodiment of an inventive bumper bar construction; 
     FIG. 1B is a cross-sectional view of the bumper bar construction of FIG. 1A and shows the web of the bumper bar after a certain deformation as a result of impact; 
     FIG. 2A is a cross-sectional view of a second embodiment of an inventive bumper bar construction; 
     FIG. 2B is a cross-sectional view of the bumper bar construction of FIG. 2A and shows the web of the bumper bar after a certain deformation as a result of impact; 
     FIG. 3 is a diagram which illustrates deformation of the inventive bumper bar as a function of load; 
     FIG. 4 is a section view of a bumper bar seen vertically from above, said bar being provided with an elastic protective element; 
     FIG. 5 shows the position of the elastic element on a first embodiment of the inventive bumper bar construction. 
     FIG. 6 shows the position of the elastic element on a second embodiment of the inventive bumper bar construction. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The inventive bumper bar construction is shown in cross-section in FIG. 1A and is made of thin metal sheet. The bumper bar includes a broad flange 1, which is comprised of flat elongated metal sheet, and an open generally U-shaped profile 2 having a narrow flange 2.1 which is embraced by two webs 2.2. The webs 2.2 have edge flanges 2.3 which extend away from one another in a common plane, preferably parallel with the plane through the narrow flange, and to which the broad flange 1 is welded, for instance by spot welding of the assembled bumper bar construction. The U-shaped profile 2 may be rolled or pressed to a trapezoidal cross-sectional shape from metal sheet, with the narrow flange 2.1 having a smaller width than the opening of the U-shaped profile 2 that faces towards the broad flange 1. The webs 2.2 also have folds 2.4 which extend along the U-shaped profile 2 and from which the outer parts of the webs 2.2 with the edge flanges 2.3 are bent outwardly from one another at a mutual angle which is larger than the mutual angle between the webs 2.2 at the narrow flange 2.1. The fold 2.4 is spaced from the broad flange 1 by a distance which corresponds at most to one third the height of the web 2.2, preferably at a distance which corresponds from one eighth to one third of said height of the web. 
     The bumper bar construction shown in FIG. 2A includes the same elements as those described with reference to FIG. 1A, but further includes a channel 1.1 which extends along the bar in the centre of the broad flange 1, and a corresponding channel 2.5 in the narrow flange 2.1. The two channels 1.1, 2.5 have the form of impressions in respective flanges 1, 2.1 and are open outwardly from the assembled bumper construction. The channels 1.1, 2.5 in respective flanges 1, 2.1 have a stiffening effect on the bumper bar in the final compression stage. 
     In the event of a collision, the inventive bumper bar is intended to absorb forces that act generally perpendicular to the plane through the broad flange 1 and the narrow flange 2.1 respectively, as indicated by an arrow F in FIGS. 1B and 2B. The bumper bar shown in FIGS. 1A and 2A will therewith be deformed in a controlled manner, meaning that the webs 2.2 will be bent successively in the manner illustrated in FIGS. 1B and 2B. In this case, the fold 2.4 in respective webs 2.2 acts as a guide for deformation of respective webs 2.2 and causes the webs 2.2 to bend towards one another while the broad flange 1 and the narrow flange 2.1 are held essentially intact. This enables the inventive bumper bar to absorb a maximum of impact energy without collapsing in an uncontrolled fashion. 
     FIG. 3 shows compression of the bumper bar in mm as a function of force in N. The curve A shows compression of a bumper bar where the fold 2.4 in respective webs 2.2 is spaced from the broad flange 1 by a distance which corresponds at most to one third of the height of said webs 2.2, whereas the curve B shows compression of a bumper bar where the fold 2.4 is located in the centre of the web 2.2. As shown by curve A, a bumper bar construction applicable to this curve is able to withstand a greater force over the whole of the compression process than the bumper bar construction that is applicable to curve B. 
     The fold 2.4 is so placed in relation to the broad flange 1 as to be able to initiate the controlled bending and compression desired, in which the webs 2.2 are bent continuously towards the broad flange 1 during compression of the bumper bar. 
     The bumper bar section shown in FIG. 4 also includes a resilient protective element 3, made of plastic foam for instance. The bumper bar is supported by two fastener means 4, which may either be placed adjacent the narrow flange 2.1, in which case the protective element 3 is mounted along the broad flange 1 as shown in FIG. 5, or adjacent the broad flange 1, in which case the protective element 3 is placed along narrow flange 2.1 as shown in FIG. 6. FIG. 4 also shows a foreign body 5 responsible for exerting the aforesaid force F indicated in FIGS. 1B and 2B. Irrespective of whether the protective element 3 is positioned according to FIG. 5 or according to FIG. 6 when the force is acting on the protective element, the fold 2.4 will control compression of the bumper bar in a manner which causes the webs 2.2 to bend successively towards the broad flange 1. 
     In general, inclination of the webs 2.2 is achieved essentially through the medium of the upper web part located between the guide 2.4 and the broad flange 1. If desired, the lower web parts, i.e. the web parts located between the guide 2.4 and the narrow flange 2.1 may also be slightly inclined towards one another in relation to the opening of the U-shaped profile 2, or may be parallel with one another. 
     It will be understood that the design of the edge flanges 2.3 may vary, e.g. in accordance with the desired configuration of the broad flange 1, and that the edge flanges need not necessarily lie in mutually the same plane. 
     It will also be understood that the inventive bumper bar may be produced as a single piece structure, such as an extruded structure. 
     The inventive bumper bar may also have a different cross-sectional shape along those parts thereof that are located at the side of the extension of the fastener means 4. 
     The inventive bumper bar may also include varying forms of stiffening means along its length. The channels 1.1 and 2.5 may therefore be intermittent. 
     The invention is not therefore limited to the described and illustrated exemplifying embodiments thereof and modifications and changes can be made within the scope of the following claims. 
     An example of a bumper bar construction which could possibly be adapted for use in the present invention, along with additional components generally associated with bumper bar construction which might be interchangeable with, or adaptable as, components of the embodiments as described hereinabove, might be disclosed by the following U.S. patent application, assigned to the current assignee of the present application and having the same inventor as the present application: Ser. No. 08/409,806. 
     Additional examples of bumper bar constructions which could possibly be adapted for use in the present invention, along with additional components generally associated with bumper bar construction which might be interchangeable with, or adaptable as, components of the embodiments as described hereinabove, might be disclosed by the following U.S. Pat. Nos. 5,080,411; 4,948,196; 4,838,606; 4,786,946 and 4,073,528. 
     Further examples of bumper bar constructions which could possibly be adapted for use in the present invention, along with additional components generally associated with bumper bar construction which might be interchangeable with, or adaptable as, components of the embodiments as described hereinabove, might be disclosed by the following World Intellectual Property Organization Patents: WO 9304897 and WO 9420322. 
     Other examples of bumper bar constructions which could possibly be adapted for use in the present invention, along with additional components generally associated with bumper bar construction which might be interchangeable with, or adaptable as, components of the embodiments as described hereinabove, might be disclosed by the following foreign patents: French Patent No. 2 207 039 and Swedish Patent 38941. As understood, the French patent relates to horizontal beams used to reinforce a motor vehicle door. The beams are used to absorb energy and thereby protect occupants in the event of side collision. The shape and configuration of the beams are disclosed in FIGS. 1-4 of the French patent. As understood, the Swedish patent is a design patent relating to the design of a construction element. Because a drawing of the construction element is included within the patent, a full disclosure of the Swedish patent is made by the drawing included therein. 
     The components disclosed in the various publications, disclosed or incorporated by reference herein, may be used in the embodiments of the present invention, as well as equivalents thereof. 
     The appended drawings in their entirety, including all dimensions, proportions, and/or shapes in at least one embodiment of the invention are accurate and to scale and are hereby included by reference into this specification. 
     All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if more than one embodiment is described herein. 
     All of the patents, patent applications, and publications recited herein, and in the Declaration attached hereto, are hereby incorporated by reference as if set forth in their entirety herein. 
     The corresponding foreign and international patent publication applications, namely, Swedish Patent Application No. 9400227-6, filed on Jan. 26, 1994, and International Patent Application No. PCT/SE95/00054, filed on Jan. 20, 1995, having inventor Martin Jonsson, as well as their published equivalents, and other equivalents or corresponding applications, if any, in corresponding cases in Sweden and elsewhere, and the references cited in any of the documents cited herein, are hereby incorporated by reference as if set forth in their entirety herein. 
     The details in the patents, patent applications and publications may be considered to be incorporable, at Applicant&#39;s option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art. 
     Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function, and not only structural equivalents but also equivalent structures. 
     The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention.