Patent GB-1419698-A (GB)
IPC: F16F7/12
Filed: 1973-04-17
Abstract: 1419698 Vehicle bumpers NISSAN MOTOR CO Ltd 17 April 1973 [19 April 1972 (4) 22 April 1972 (2) 29 Aug 1972] 18529/73 Heading B7J [Also in Division F2] An impact-dampening device comprises a first tubular member having a first end portion having at least one longitudinal enlarged portion, the cross-sectional shape of that portion being substantially the same as that of the remaining portion of the first tubular member, and a second tubular member having a second end portion having at least one longitudinal enlarged portion, the cross-sectional shape of that portion being substantially the same as that of the remaining portion of the second member, the second end portion being received by surface-to-surface engagement in the first end portion, the first tubular member being made of a malleable material such that the first tubular member is deformed in cross-section along its length when the first and second members are forced to move longitudinally relative to each other in response to an impact. One of the simpler embodiments is shown in Figs. la, 1b. A first elongated tubular member 30 is secured to a rigid part 34 such as a road vehicle cross-member, and has an enlarged end portion 31 enclosing the enlarged end portion 33 of the second elongated member 32, also tubular in this instance, and secured to an impact receiving member 35 such as the vehicle bumper. Alternatively, portion 33 may surround portion 31. Where both members are of malleable material, the inner one may incorporate a less-malleable reinforcement member 38, Fig. 8. The first tubular member 30 may have a longitudinal extension 36, Fig. 8, not provided in Fig. 1, to prevent separation of the members under tension, and resist bending stresses. The inner of two members may have two adjacent enlarged end portions each accommodated in a separate enlarged end portion of the outer member, or both accommodated in a single lengthened end portion thereof; the "inner" end portion nearer the end of the member may be smaller than the adjacent one. The longitudinal extension 36 may be replaced by a weld line or by transverse rupturable pins. A third member, optionally hollow, may be attached to the second member (see Fig. 15a). All the members may be urged towards one another by a flexible component, e.g. a wire rope, extending through the bores of the members between an adjustment bolt at the outer end and a cross-member at the inner end. The inner end portion may be tapered and of rigid material, e.g. the tapered end of a cylinder of otherwise-uniform diameter; or the part 85 of the cylinder, Fig. 15a, may be of less diameter than the end portion 86. In Fig. 15a there are first and second elongated tubular members 80, 81 respectively, and a third member, cylinder 85, forming part of an elongated longitudinally contractible unit 82, the unit 82 being capable of returning to its initial length if subjected to an impact smaller than a predetermined value and then relieved of the impact; it incorporates a piston (not shown) subject to a fluid-pressure restoring- force and having a piston-rod 88 attached to a bumper F. Two such assemblies extend between the bumper F and dashboard D, Fig. 15b, and above them two similar assemblies, each having a third hollow member 39 instead of a piston- and-cylinder unit, are located. Preferably a panel 94, separate from the body structure B, interconnects the second elongated members 81, 32, and a similar panel 95 interconnects cylinders 85 and members 39. Optionally a third panel, 96, Fig. 15a, connects the first members 80, 30, and also extra outer elongated hollow members 93, 93<SP>1</SP> of square sections, Fig. 15b. The panels prevent buckling of individual components and distribute the impact laterally amongst the assemblies. Fig. 15f shows the fullycollapsed condition, including that of the piston- and-cylinder units. In another embodiment, the upper assemblies and panels of Figs. 15a, 15b, are omitted and the extra outer members 93 extend from the dashboard to the front of the vehicle body (Figs. 14a, to 14d, not shown). In Fig. 16 (not shown), the upper assemblies and panels of Figs. 15a, 15b, are omitted. In this embodiment, as in Figs. 15a, 15b, where the extra outer members 93 extend only part of the way from the dashboard D, the part of the body B including these extra members constitutes a non-contractible section, which thus protects the engine, &c., and prevents it from being pushed into the passenger compartment C, while the part of the body in front of this constitutes a contractible section-see Fig. 15f.