GB2030082A

GB2030082A - A thermally stable bumper finisher structure

Info

Publication number: GB2030082A
Application number: GB7929558A
Authority: GB
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1978-08-28
Filing date: 1979-08-24
Publication date: 1980-04-02
Also published as: JPS6036970B2; FR2434733B1; FR2434733A1; DE2934722A1; GB2030082B; JPS5531610A; DE2934722C2

Abstract

A bumper comprises an elongated shock-absorbing member (70), and an ornamental finishing assembly (80), made of a different material from the shock-absorbing member, and supported on an elongated surface thereof. The characterizing feature of this invention is that the ornamental finishing assembly is formed of a plurality of finisher members (81, 82) arranged end to end along the said surface, with their ends overlapped, so as to allow for differential thermal expansion of the finisher and the shock- absorbing member. In some embodiments described the finisher is in three parts, and the center part, which extends along the elongated surface, is attached to the shock- absorbing member so as to be slidable with respect to it, so as further to facilitate the allowance for thermal expansion. <IMAGE>

Description

SPECIFICATION A thermally stable bumper finisher structure The present invention relates generally to bumper structures for vehicles, and, more particularly, to a bumper structure including a shock-absorbing member and an ornamental finishing assembly, which is fixed to a surface of the shock-absorbing member.

Figs. 1 and 2 of the accompanying drawings show generally a prior art bumper structure. The main body of the bumer comprises a shock-absorbing member 30 of substantially L-shaped cross section, and is conventionally made from rubber, synthetic resin such as polypropylene, fiberglass-reinforced plastic, polyvinyl chloride, or the like, Further, on the surface of the shock-absorbing member, which is elongated, there is fitted an ornamental finisher 40, to a surface of one arm of the L-shaped cross section. Typically, this finisher 40 is mounted on the part of the shockabsorbing member which will be uppermost when the bumper is fitted to a vehicle.

Such a finisher 40 has been conventionally mounted by bolts 50 and nuts 52, spaced along the whole length of the finisher, and by an engaging part 42 of the finisher which is bent over and engaged with a suitable part of the shock-absorbing member, such as a groove or corner.

However, a problem has arisen in parts of the world where the bumper is subject to large variations in temperature, because the two members 30 and 40 differ greatly from one another in their coefficients of thermal expansion; the material of the finisher is conventionally metal. When the temperature change is large, this difference between the coefficients of thermal expansion of these two members creates strain and deformation in them, because they are secured together along the entire length of the bumper, by the bolts and nuts.

Further, the use of relatively many bolts and nuts results in inefficient and expensive assembly procedures.

Therefore, it is an object of the present invention to provide a bumper structure which is relativeiy free from strain and deformation, on change in ambient temperature.

It is a further object of the present invention to provide a bumper structure which is easy to assemble.

According to the present invention, these and other objects are accomplished by a bumper structure, for mounting on a vehicle, comprising: an elongated shock-absorbing member; and an ornamental finishing assem bly, made of a different material from the shock-absorbing member, and supported on an elongated surface thereof; characterized in that the ornamental finishing assembly is formed of a plurality of finisher members arranged end to end along said surface, with their ends overlapped.

The present invention will become more clear with reference to the following description of several preferred embodiments, and with reference to the accompanying drawings in which, Figure 1 is a perspective view of a prior art bumper structure; Figure 2 is a cross section taken along the line ll-ll of Fig. 1; Figure 3 is a perspective view of a first embodiment of the present invention; Figure 4 is a cross section taken along the line IV-IV in Fig. 3; Figure 5 is a cross section taken along the line V-V in Fig. 3; Figure 6 is a fragmentary perspective view of a clip shown in Fig. 5; Figure 7shows an alternative form of the clip, and is a view similar to Fig. 5; Figure 8 shows a third possible form of attachment of the finisher, and is another view similar to Fig. 5; Figure 9 is a perspective view of the clip of Fig. 8;; Figure lOis a view similar to Fig. 8, but showing another modification of the bumper structure according to the present invention; Figure 11 is a view similar to Fig. 10, but showing yet another modification of the bumper structure according to the present invention; and Figure 12 shows a plan view of another modification of the bumper structure according to the present invention.

Referring first to Figs. 3 to 6 of the drawings, there is shown a first preferred embodiment of the bumper structure according to the present invention. The basic bumper consists of an elongated shock-absorbing member 70 of similar material to that of the prior art explained above, which has a substantially Lshaped cross section, as described above. An ornamental finisher 80, which is made of metal in this embodiment, is mounted along the top surface of this shock-absorbing member 70. According to the present invention, this ornamental finisher is formed in three parts: two end members 81, and a long intermediate member 82. Each of the end members 81 is fixed securely to the shockabsorbing member 70 by concealed bolts 90 and nuts 91; the heads of the bolts 90 are fixed to the underside of the members 81.

Again according to the present invention, the ends of the two end members overlap the ends of the intermediate member 82, at portions P, so the ends of the member 82 are underneath the ends of the members 81.

Further, as seen in Figs. 5 and 6, the edges of the intermediate member 82 are turned over along its length. One of these turned over edges, which are denoted by reference numeral 83, is engaged with the rear edge of the top surface of the shcok-absorbing member 70 (as seen in Fig. 5), while the other turned-over edge 83 is engaged with a plurality of clips 71 which are provided in a stepshaped longitudinal depression 72 formed on the outer surface of the shock-absorbing member 70 near the elbow part of the L-shaped cross-section. Thus the intermediate member 82 is supported on the shock-absorbing member 70 so as to be slidably movable along it.

In this particular embodiment, each of the clips 71 is formed as a substantially L-shaped outwardly convex facing tongue whose upper end 71 a is free, as may be seen in Fig. 6.

These tongues are formed by cutting the elbow of the member 70. As a modification, shown in Fig. 7, the lower ends of these tongues may be free instead.

Figs. 8 and 9 show another alternative form for these clips, in which neither end is free, but in which the clip body is formed substantially V-shaped in cross section, and the ends of the V-shape are substantially thinner than the vertex, as they join onto the bottom of the depression 72, so that these thinner end portions 73 can be bent to allow resilient engagement of the clips with the turned-over edge 83.

Fig. 10 shows another method of attaching the ornamental finisher intermediate member 82. The member 82 is again formed with turned-over edges 83, and one of these edges 83 is engaged with a lengthwise extending groove 74 provided at the bottom of the shock-absorbing member, while the other edge 83 is resiliently engaged in another lengthwise extending groove 75 provided on the outer surface of a lip 76 on the edge of the shock-absorbing member 70. As seen in the Figure, this lip forms a sort of serif-shape, in combination with the L-shaped cross secton of the shock-absorbing member 70.

Fig. 11 shows another modification of the present invention, wherein ribs 78 are provided on the top of the shock-absorbing member 70, and on the outward faces of these ribs 78 grooves 77 are cut lengthwise, into which the turned-over edges of the intermediate member 82 engage.

When such a bumper is being assembled, first the intermediate member 82 is placed and clipped into position on the top of the shock-absorbing member 70, and then the end members 81 are fixed to the ends of the shock-absorbing member 70 by the bolts and nuts, so that their ends overlie the ends of the intermediate member 82. This is obviously much easier than the assembly of the prior art structure illustrated in Figs. 1 and 2.

Further, in Fig. 1 2 is shown yet another embodiment of the present invention. In this case the ornamental finisher 80 is formed of just two members 84, which overlap at a central portion P, like the members of the other embodiments shown. The other ends of these members 84 are fixed by ornamental bolts 91. This embodiment is advantageous because in it the finisher 80 has only two parts, which makes for convenience of manufacture and assembly.

In all these embodiments the feature of overlapping of the portions of the finisher assembly is such that when the temperature changes these ends can slide over one another freely, so that srain and buckling in the bumper structure due to differential expansion of the parts thereof are effectively avoided.

It is quite within the scope of the present invention that the finisher assembly should be formed of more than three parts, as before overlapped at their ends, although the embodiments shown have all employed the structure using either two or three parts. The important feature is that this overlapping allows for differential thermal expansion.

Claims

1. A bumper structure, for mounting on a vehicle, comprising: an elongated shock-absorbing member; and an ornamental finishing assembly, made of a different material from the shock-absorbing member, and supported on an elongated surface thereof; characterized in that; the ornamental finishing assembly is formed of a plurality of finisher members arranged end to end along said surface, with their ends overlapped.

2. A bumper structure according to claim 1, wherein the finisher members at the extreme ends of the finishing assembly are fixed firmly to the shock-absorbing member.

3. A bumper structure according to claim 2, wherein the finishing assembly further includes an intermediate finisher member which is supported on said elongated surface so as to be movable along it.

4. A bumper structure according to claim 3, wherein the shock-absorbing member is formed with a clip integrally thereon which retains the intermediate finisher member.

5. A bumper structure according to claim 4, wherein the shock-absorbing member is formed with a step-shaped longitudinal depression on an outer surface, jn which depression is located the clip.

6. A bumper structure according to claim 5, wherein the clip is formed with a tongue having an outward facing substantially Vshaped cross section.

7. A bumper structure according to claim 6, wherein the ends of the V-shape of the clip are thinner than the rest of the clip, and are connected to the part of the shock-absorbing member which forms the depression, so that they are able to deform and allow the body of the clip to move relative to the recess.

8. A bumper structure according to any of claims 1 to 7, wherein the shock-absorbing member has a substantially L-shaped cross section, with the finishing assembly being laid along the surface of one arm of the L-shape which is remote from the other arm of the Lshape.

9. A bumper structure according to claim 8, wherein the shock-absorbing member is formed, approximately on the outer surface of the L-shape.

1 0. A bumper structure according to claim 8 in its appendancy to claim 5, wherein the step-shaped longitudinal depression approximately of the shock-absorbing member is formed on the outer surface of the elbow of the L-shaped cross-section.

11. A bumper structure according to claim 10, wherein the intermediate finisher member is formed with turned-over edges which extend along its length, one of which engages the clip, and the other of which engages the end of said one arm of the L-shaped crosssection of the shock-absorbing member.

1 2. A bumper structure according to claim 8 in its appendancy to claim 3, wherein the intermediate finisher member is formed with two turned-over edges which extend along its length, and the shock-absorbing member is formed with two grooves, one of which extends along the length of that part of the shock-absorbing member whose cross-section forms the end of one arm of the L-shaped cross-section of the member, and the other of which extends along the length of that part of the shock-absorbing member whose cross-section forms, approximately, the outer surface of the elbow of the L-shaped cross-section of the member; and wherein one of the turned-over edges engages with one of these grooves, while the other engages with the other of these grooves.

1 3. A bumper structure according to claim 12, wherein the end of said one arm of the substantially L-shaped cross-section of the shock-absorbing member is formed with a slight serif-shape, and wherein the groove formed on said end is formed in this serifshape.

14. A bumper structure according to claim 8 in its appendancy to claim 3, wherein the intermediate finisher member is formed with two turned-over edges which extend along its length, and the shock-absorbing member is formed, on the outside side of the one part whose cross-section forms one leg of the Lshaped cross-section of the member, with two longitudinally extending ribs, each of these ribs being formed with a longitudinally extending groove thereon on its outer side, and wherein one of these turned-over edges engages one of these grooves, while the other of these turned-over edges engages the other groove.

1 5. A bumper structure according to claim 2, wherein the finishing assembly comprises only two finisher members and the overlapping portions of these two finisher members are substantially in the middle of the said elongated surface.

1 6. A bumper structure substantially as described with reference to, and as illustrated in Figs. 3 to 6, or Figs. 8 and 9, or Fig. 10, or Fig. 11, or Fig 1 2 of the accompanying drawings.