1. Field of the Invention
The present invention generally relates to automobile lamps positioned at the automobile's front end and/or rear end. More specifically, this invention relates to an automobile headlamp or taillamp housing that is capable of elastic deformation, yet is rigidly, directly or indirectly, attached to a fixed chassis component or body component (i.e. trunk, fenders, rear quarter, etc.) of the automobile. The flexible lamp mounting arrangement is able to withstand substantial flexure when the automobile bumper sustains an impact by an object and, therefore, the flexible lamp arrangement is particularly well suited for use with impact-absorbing bumpers that automatically rebound from a frontal impact.
2. Description of the Prior Art
Generally, automobile designers or stylists would like to create aerodynamic body shapes. Their motivation is not merely to reduce drag, but to create contemporary sculpted shapes that appeal to the marketplace. The automobile designers or stylists, however, are hampered by a variety of functional, economical, and other restraints.
With the advent of energy or impact-absorbing bumpers, front and rear ends of an automotive vehicle have been required to undergo significant design changes in order to accommodate the stroke of the bumper, that commonly can be as much as three to four inches. Generally, with respect to the front and rear end of a vehicle, designers would like a clean, convex transition from the front edge of the bumper rearward to the hood area and from the rear edge of the rear bumper forward to the sheet metal associated with the trunk area and rear deck lid. However, when viewing most vehicle designs currently available in the marketplace, this transition is normally an inward, concave box shape as shown in FIG. 1. The front bumper protrudes forward from the vehicle body, or the rear bumper protrudes rearward from the rear sheet metal in order to provide compliance with federal and automotive original equipment manufacturer's vehicle impact standards. These standards generally state that no damage can occur to non-bumper components or safety items, such as headlamps or taillamps, during 5 miles per hour barrier and front impacts, or 3 miles per hour pendulum impacts. Therefore, to achieve this objective, the original equipment manufacturing engineers have brought the bumper out away from the front and rear body panels, headlights, taillights, hood and grille, so that the bumper may stroke, thereby absorbing the impact energy without allowing intrusion into the components with subsequent damage. The clear result from such design is that the vehicle appears boxy, non-aerodynamic, and antiquated.
A closely related problem to the ability to absorb the impact energy of these federal and automotive vehicle impact standards concerns the location of the engine within the engine compartment. For example, in an attempt to obtain more passenger space within a vehicle, recent practice has been to push the mounts of the engine further and further towards the front of the vehicle. Accordingly, the ability to provide additional passenger compartment space is directly affected by the space available in front of the engine to enable moving the engine forward to obtain the maximum passenger compartment space. However, since the overall length of the vehicle is subject to limits dictated by the original equipment manufacturer, bringing the bumper forward away from the body, headlight, hood and grille intrudes into the maximum length, and the front end space of the vehicle becomes extremely valuable in that it directly affects the ability of automotive engineers to move the engine forward in an attempt to create additional passenger compartment space.
Similar problems existed with respect to automobile grilles, and such problems were solved by the use of a grille that is mounted substantially flush with the surrounding automobile body panels and bumpers, while also being capable of deflecting with the stroke of the impact-absorbing bumper during impact, thereby obviating the need for the grille to either pivot about an anchor point or to be mechanically displaceable with the additional hardware. Such a grille is disclosed in U.S. Pat. No. 5,205,597, owned by the common assignee hereof. The use of the teachings of this earlier invention, however, allowed the grille to be brought into the impact zone and absorb impact without damage. Unfortunately, while this helped to achieve a more aerodynamic and contemporary look in the grille area, the transformation is incomplete because along either side of the grille the fragile headlight system still requires protection, resulting in the boxy, non-aerodynamic situation as depicted in FIG. 1.
Several automotive equipment manufacturers have attempted specific solutions to this problem, but in doing so have failed to take into consideration the original equipment manufacturer's limitations set forth above, as well as the availability of space between the front bumper and the front of the engine in an engine compartment where the headlight system must be appropriately mounted. As set forth above, the traditional solution is to position the headlamps or taillamps entirely out of the path of the bumper during recoil after impact. This approach generally entails placing the automobile's headlamps rearward of the bumper or taillamps forward of the bumper, resulting in an extremely square looking profile that has little appeal according to modern design trends as depicted in FIG. 1. In addition, clearly such a design is not aerodynamic, but this approach has been generally followed for lack of a better solution. Another solution recently attempted by some of the original equipment manufacturers, is to require the headlamp and/or taillamp to be displaceable such that it can either pivot or otherwise move out of the path of the bumper during energy absorbing impact. Preferably, this approach allows the headlamp and/or taillamp to be mounted flush with the surrounding hood, front end, body panels and bumper, to enhance the styling and aerodynamics of the automobile by proving aesthetically pleasing, continuous smooth contour surfaces between the hood, bumper and headlamp lens surfaces. Such an approach is illustrated in Tomforde, U.S. Pat. No. 4,475,148, wherein the headlamp upper and lower housing compartments 3, 6, are pivotably mounted to a fixed component 4, at axis 5, to allow resilient cushioning of an impact in the longitudinal direction of the vehicle to minimize property damage and personal injury. This approach allows the top of the headlamp to pivot rearward when the headlamp is contacted at the bottom edge so as to reduce or prevent property damage in a collision with the vehicle and/or a stationary obstacle, as well as to avoid injury to a pedestrian by yielding in a longitudinal direction about pivot point 5. This approach appears extremely impractical as bumper heights are standardized on passenger vehicles, and an impact on the lower portion of the headlamp would not cause enough rotation to prevent the headlights from becoming severely damaged in case of an impact in a minor collision with another vehicle or a stationary obstacle.
Another example of an attempt to solve the above problems relating to the location of headlamps or taillamps in the impact zone is taught by Delmastro et al., U.S. Pat. No. 4,466,646. In this reference the lamp assemblies are mounted to an impact bar by the use of U-shaped springs to permit the lamp assembly to swing from its illustrated operating position to a protected position within the confines of the impact bar assembly in response to predetermined frontal impacts. The bumper fascia is mounted to an impact energy absorbing unit and its associated impact bar to absorb side or frontal impacts, store the energy in the impact bar and to avoid transmitting the energy into the vehicle frame, bodywork, or other vehicle components. Any frontal or side impact will permit the hinge assembly limited side and compound movement of the lamp assembly, so that it will not be damaged by any material of the energy absorbing unit crowding the headlamp assembly on corner impacts. After the impact load is removed, the impact bar and end section recover at predetermined rates to their original positions. The lamp assembly, of course, being connected to the U-shaped spring member, will likewise recover to its original position. Note that although this type of solution is proposed for fog lamps and signal lamps, the reference completely fails to set forth any solution, whatsoever, for avoiding damage to the headlamp in a frontal zone collision. Clearly, the design criteria to avoid damage to headlamps requires the headlamps to be set rearward a sufficient amount to allow the bumper to properly stroke during frontal impacts.
Another attempt to protect fog and taillamps mounted in the impact zone is shown in Vogelgesang, U.S. Pat. No. 5,288,177, wherein a fog lamp and turn signal lamp are mounted to the elastic bumper covering to allow the fog and turn signal lamp unit to move backwards in the case of a 30.degree. pendulum impact after it has been acted upon by the impact and to return to its original position. The fog lamp and turn signal housing are attached to a bumper covering that, when impacted, moves towards the rear of the vehicle by pivoting about a fixed pivot mounted on the chassis that provides appropriate support for the fog lamp and turn signal housing, and allows the housing to pivot rearwards to absorb the impact and return to its original position thereafter. The supporting element is mounted at one end at a fixed member attached to the wheel housing and to the fog lamp and turn signal housing to allow the supporting element to pivot rearwards. After impact, the elastic bumper covering with the lamp units and the supporting element are returned to their original positions by the restoring force of the pneumatic impact absorbing devices.
In Roschinski et al., German patent publication DE 3802104 A1, the lighting unit is mounted in the area of the impact zone. Through the use of spherical balls mounted in a spherical socket the lighting unit is allowed to be removed from the socket upon impact in the longitudinal direction, and returned into the spherical socket by two compression coil springs located between the housing and the body of the vehicle. Because of the use of two spherical sockets that are mounted respectively in an upper and lower zone, the reference further teaches that a shock load acting obliquely from one side only will cause only one of the spherical balls to be displaced from the spherical socket and resume its original position through the use of one coil spring providing sufficient force to again engage the spherical ball with the spherical socket upon removal of the impact force. A similar arrangement is proposed for the fog and turn signal lamps, as well as for the rear lamps of the vehicle. As an alternative to the coil springs, a hydraulic, pneumatic or magnetic system that generates an appropriate force for restoring the position of the housing is also contemplated.
A further attempt to allow headlamps to be mounted forward, flush with the front fascia of the vehicle, is discussed in Kodama et al., Japanese Patent JP3-208738-A2, wherein the headlamp is mounted to a guide rail spaced a predetermined distance from side frame members, and interconnected with a connecting bar whose lower end is connected to the side member and upper end to the movable frame containing the headlamp, and adapted for sliding on the guide rail. The torsion bar system has a front part mounted in close proximity to the bumper fascia so that upon impact the bumper fascia collapses and retreats, activating the crank portion of the torsion bar system whereby the connecting bars are pivoted to slide the headlamp in a rearward direction away from the area of the impact zone to prevent damage thereto. After restoration of the bumper fascia to its original position, through the use of impact absorbing material such as foam, the torsion bar system utilizes its stored energy to return the headlamp along the guide rails to its original forward position. An alternate embodiment discloses the use of a scissor-like two bar mechanism that operates in combination with a torsion bar system to retract the headlamp in a rearward direction upon impact and through the stored torsional energy in the torsion bar system return the headlamp to the original position upon release of the impact with the bumper fascia.
As can clearly be observed from a review of the prior art, with the exception of German Patent DE 3802104-A1 and Japanese Patent 3-208738-A2, the prior art addressing of this problem only concerns fog lamps or turn signal lamps where damage criteria after impact, as established by government entities or original equipment manufacturers, is very low, or nonexistent. The proposal disclosed in the German reference relies mostly on a complex spring system to return the housing to its original position while the Japanese reference teaches that the bumper impact absorbing material will allow the pivoting mechanism cooperating therewith to return the lamp to its original position Since none of the bumper impact absorbing materials are required to return a headlamp to its original position by any automotive regulations, it is not possible to rely on such a system to permit controlling the headlamp to return to its original position after a bumper impact due to the strict regulations and tight tolerances on headlight aim patterns that would not allow any misalignment of aim pattern after impact outside of the tolerance limitations. Further, both the teachings of the German and Japanese patents have completely neglected the value of the space considerations surrounding the headlamp mounting area that directly reflects upon the forward placement of the engine and, in turn, the amount of space available in the passenger compartment of the vehicle. Accordingly, none of the systems provided in the prior art are adaptable to headlamps or taillamps that have strict regulations concerning damage after bumper impacts.
Therefore, what is needed is a simple, cost effective headlight and/or taillight system that can be brought into the impact zone to provide designers the freedom to create flush, convex-shaped, aerodynamic front end systems for vehicles that after impact return to their original positions without damage and continue to operate within the limits of the specifications set forth for headlamps and taillamps for automotive vehicles.