Patent WO-2013014477-A1 (WO)
Title: Foldable bicycle
Inventor: GERENCSER GABOR
IPC: B62K15/00
Filed: 2012-07-20
Abstract: The invention relates to a foldable bicycle which is suitable for use as a means of transport (I) in its self-propelled use position in its folded-out state, for transporting (II) and for storage (III) in its folded-up state and in both its folded-out and folded up states has fixing components for maintaining the reliability of these states, and in its folded-up state it has significantly lower space demand as compared to its folded-out state, in the same as with rigid frame-structured bicycles unsuitable for being folded the bicycle has a frame structure fitted with a front wheel (5) and a rear wheel (6), a handlebar column (7) fitted to the frame structure, handlebars (7a) fitted to the handlebar column, a seat post (8) also fitted to the frame structure and a seat (8a) fitted to the seat post (8), furthermore it has a drive chain (173), and crank arms (171) fitted with pedals (171a) as well as a drive mechanism (17) including chain wheels (172), the frame structure is assembled from parts that, by releasing the aforementioned fixing components, are capable of movement as compared to each other, characteristically relative angular rotation, for the purpose of realising the relative angular rotation there are structural elements, favourably hinge joints (9, 10, 1 1, 12), permitting this inserted between the parts of the frame structure that are connected to each other. The solution according to the invention is based on that the frame structure is formed by a four-member kinematic chain forming a three-dimensional rectangle, which has a rear member (1) belonging to the rear wheel (6), a front member (2) belonging to the front wheel (5) and so supporting the handlebar column (7), a third member (3) supporting the seat post (8), and a connection rod (4) inserted between the front member (2) and third member (3) also realising the spatial rigidity of the entire frame structure when it is in its use position, among the hinge joints (9, 10, 1 1, 12) permitting spatial rotation of the members of the kinematic chain as compared to each other it also has a central hinge joint (9) between the rear member (1) and the front member (2) permitting the turning of the front member (2) underneath the rear member (1), a lower hinge joint (10) between the front member (2) and the connection rod (4) serving to guide the front member (2) before being turned underneath, an upper hinge joint (11) at the other end of the connection rod (4) providing the connection of the connection rod (4) to the third member (3) and a rear hinge joint pair (12) encompassing the rear end of the rear member (1) as a fork and permitting the turning of the third member (3) along the rear member (1), among which the axis line (A) of the central hinge joint (9) is slanted in two directions, because in top view it is at a slight, favourably max. 20° angle (a) to the horizontal lateral central axis (x- x) perpendicular to the longitudinal vertical central plane (y-y) of the vehicle, and in rear view it is also at a slight, favourably max. 20° angle (β) to the longitudinal vertical central plane (y-y).