GB1376786A - Structures having deformable members - Google Patents

Abstract

1376786 Energy absorbing devices SOC ANON AUTOMOBILES CITROEN 6 March 1972 [19 March 1971] 10256/72 Heading F2E A deformable structure comprises a substantially undeformable body and a plastically deformable member substituted by two sheets each sheet having a first portion, contacting the first portion of the other sheet in face-to-face relationship, and a second portion including a loop extending through approximately 180 degrees the loops extending in opposite directions and being secured to the body a guide element for each loop so that upon deformation each loop moves along its respective guide element, the first portions progressively separating, and being guided by further means. The sheets each comprise three pairs of bands 4, 5, 6, of decreasing thickness from the centre and held in a sleeve comprising the two outside bands joined by two lateral bands. The bands 4, 5, 6 are adhered preferably by welding spots and are held at the other end in a sleeve 11, e.g. in a vehicle bumper or steering-column. The rigid body is a rectangular cross-section box 1 having a reinforced end 1a with an end cap 13 providing the guide means 12. The bands 4, 5, 6 are further looped around the end 1c of the box 1 or they extend laterally, Fig. 5, and are held by bolts to the box 1. The guide elements comprise two walls 3b spaced from the box walls tapering toward the box walls near the end 1c and joined by two opposed walls adjacent the box walls. Alternatively, the guide elements comprise two opposed solid parts providing a similar guide profile to the guide elements 3b. When a compressive load is applied to the sleeve 11, the bands absorb energy by the deformation due to new loop formation along the elements 3b and by the rupture of the adhesion points between the two central bonds 4. The sleeve surrounding the sheets does not inhibit deformation since notches are provided at the corners, running the length of the sleeve, to provide easy rupture.