GB1327625A - Vehicle chair having a resiliently supported seat - Google Patents

Abstract

1327625 Vehicle seats K G NYSTROM 28 Oct 1970 [31 Oct 1969 20 April 1970] 51154/70 Heading A4U In a vehicle seat, a seat part 2 is resiliently supported against vertical downward movement by a support structure 1 which includes a helical compression spring 10 having a winding pitch which varies along its length, the part 2 being connected in a parallelogram linkage with the support 1 by pairs of parallel arms 4, and being coupled to the spring by linkage including transverse shafts 8 journalled in the support 1 and rigid with the arms 4, the spring 10 acting on an arm19 rigid with the front shaft 8, at a point displaceable along the arm to vary the spring force transmitted to the seat and adjust the seat to suit the users weight or differing ground conditions. The pitch of the spring 10 has a maximum value at the middle of the spring and a minimum value at each end and the ends of the spring rest on a bracket 11, secured to the top wall of the structure 1, and on a shaft 13, mounted in a bracket 14, secured to the bottom wall of the structure, the ends of the legs of a yoke 15 mounted on the shaft 13 being connected by a shaft 16 which has a stud 17 which engages a selected one of a series of locking teeth 18 in a slot in the arm 19. The stud 17 is gripped by arms 20 of an operating lever 21 to rotate the shaft 16 to release the stud 17 for adjustment along the slot. The arm 20 may be spring- urged to locking position. A bolt 23 passing through a threaded hole in the yoke 15 presets the tension of the spring. A shock absorber 24, pivoted to the top wall of the structure 1, has an operating member 31 for adjustment to counteract rapid movements of the seat. A back 3 is mounted on the seat part 2 by a bracket 5, the inclination of the back being adjustable by an operating arm 6. In modifications the spring is enclosed in the bracket 5 and extends transversely of the seat the operating lever having a cam roller which contacts a guide surface on the support structure or the spring acts on the arm by a nut which is non-rotatable relatively to the arm and is mounted so as to be axially displaceable on a threaded bolt, which extends lengthwise of the arm, a toothed wheel on the bolt being operable by a ratchet wrench to rotate the bolt.