GB652176A - Improvements in or relating to folding push chairs - Google Patents

Abstract

652,176. Folding push-chairs. THOMAS, G. April 20, 1948, Nos. 10890/48 and 9982/49. [Class 108(i)] A folding push-chair in which each wheel is carried by a bracket capable of pivoting about a vertical axis so that in the folded condition the wheels are disposed in parallel transverse planes, as described in Specification 177,959, [Class 108(i)], is so arranged that the folding side frame members are connected to the brackets in such a way that the latter are automatically rotated into and out of their operative position when the chair is extended and folded respectively, and one of each transverse pair of wheels opens earlier and closes later than the other, so as to prevent fouling of the wheels during opening and closing. In the construction shown in Figs. 1 and 4 the side arms 10 are secured to intermeshing toothed segments 9 which gear with pinions 8 connected to the vertical pivots 6 of the wheel brackets by lostmotion couplings 12, 13 controlled by springs 14. In order to prevent fouling of the brackets and wheels during folding and unfolding, the pair of springs 14 on one side of the chair are arranged to advance the rotation of the associated brackets, while those on the other side retard the movement of the brackets. In the modification according to Fig. 10, each side arm 10 is connected by a link 16 to a nut or block 15 slidable along a variable-pitch screw member 6, the latter consisting of a square-section bar twisted to form a helix 17. To avoid fouling of the brackets and wheels, the helices of the brackets on opposite sides of the chair have differeing characteristics, e.g. those on one side are quick-start while those on the other are slow-start. The wheel locking mechanism forms the' subject of Specification 652,220.