Patent GB-1411062-A (GB)
Title: Shock absorbers
IPC: E01F15/04
Filed: 1973-01-26
Abstract: 1411062 Crash barriers E BAUMANN 26 Jan 1973 [31 Jan 1972 21 March 1972] 4213/73 Heading E1G [Also in Division F2] A deformable shock-absorber particularly for incorporation in or with a guide rail or crash barrier for a roadway comprises at least one metal strip bent at least once transversely to its longitudinal direction, the two legs extending from each bend having cross-sections different from a straight line and being oppositely profiled (so that they nest together on complete collapse of the shock-absorber), the bend being formed as the geometrical intersection between the profiles of the two legs, and at least one section of the bend being at least partially dislocated upon forcing of the two legs towards each other. Figs. 1 and 2 show a part of a shock absorber in section and elevation. During compression, the angle between legs 1 and 2 is reduced, the fold is progressively altered along its length so that at the point nearest the observer the fold "rises", part of leg 2 being transposed to leg 1, while at the remote extremity of the fold no transposition occurs, and the angle between the fold and the righthand edge of leg I becomes progressively greater (until at complete collapse it is a right angle). When Fig. 9 is seen from above and to the left, leg 2 appears convex while leg 1 appears concave. Fig. 53 is another example of a simple shape which includes a lateral flange interrupted by a slot 5, the slot 5 serving to control the dislocation at the fold and avoid stresses and cracks. On complete collapse the "profiles" nest together. Fig. 13 shows in plan a guide rail 3, e.g. for a motorway, connected to a support 4 by means of a zig-zag shaped shock absorber 1, 2. In Fig. 14, two shock absorbers are pivoted each by a leg 2 to support plates 4 and are joined by overlapping legs 21 to a spacer connected to a guide rail 3. Further smaller shock absorbers, with legs I of unequal length to provide for progressive collapse, are joined by their legs 2 to the upper of the two pivoted shock absorbers. In Fig. 20 a stack of shock absorbers is disposed in a box secured to a support plate 4, and at impact on guide rail 3 a lever connected to the guide rail pivots to compress the shock absorbers. In Fig. 45 two Z-shaped shock absorbers on the left are secured by one of their overlapping left legs 1 to a guide rail 3 and by both their other overlapping right legs I to a post 4. A similar arrangement is provided on the right of the post. At regions not occupied by shock absorber assemblies the guide rails are connected by struts which are rigid in compression, so that on impact from the left, Fig. 46, the struts, moved to the right by inward movement of the left-hand guide rail, force the right-hand guide rail 3 to move to the right, with consequent "unfolding" of the shock absorber assembly on the right of post 4.  Fig. 36 (not shown) shows the left hand assembly only of Fig. 45 applied to the post 4, while in Fig. 37 (not shown) a further Z- shaped shock absorber is secured, by its legs I between the respective pairs of legs I of the shock absorbers of Fig. 36, its leg 2 lying between and parallel to the other legs 2. Fig. 34 (not shown) is a variant of Fig. 37 where the middle shock absorber is halved being secured only to the guide rail, while the two legs I at the post do not overlap. Fig. 35 (not shown) resembles the left-hand side of Fig. 45, but the legs 1 adjacent post 4 do not overlap, and subsidiary shock absorbers like those in Fig. 14 are secured by their legs 2 to the underside of leg 2 of the upper shock absorber. Fig. 38 (not shown) is another minor variant of Fig. 37. Fig. 57 shows a metal strip with apertures and fold lines before bending, while Fig. 59 shows the bent sheet, demonstrating the convex character of leg 2 and the concave character of leg 1, (better seen in Fig. 73 - see below). Fig. 40 shows a pair of shock absorbers connected to a support structure 4 and two guide rails 3, each shock absorber having a convex central leg 1 similar to leg 2 of Fig. 59 joined to two concave outer legs 2 each similar to leg 1 of Fig. 59, and each outer leg 2 being joined to a further, vertical, leg I of V-section, connected to the guide rails as shown. The guide rails here are connected by rigid struts as in the case of Figs. 45, 46 and the pattern of collapse (Fig. 43, not shown) resembles that of Fig. 46. Fig. 73 is typical of several applications of the shock absorber of Figs. 57, 59. Legs 1 are intended to be connected to a post (not shown) with the interposition of an optional spacer 8. The overlapping flat portions of the assembly, secured to the guide rail 3, do not in fact form part of the shock absorbers but perform a connecting function. The cross-section of each leg may be simple or multiple U or V, or variants of these; the included angles are reduced when the legs are pressed together.