Patent ID: 9107476
Filing Date: 2015-08-18
Classification: A43B

Abstract:
1. An adjustable spring device usable by a user for walking and running, said device is associated with the user's footwear, said device comprising: an upper sole of a predetermined stiffness attached to or integrated into the footwear; a lower sole of a predetermined elasticity, situated below the upper sole, the lower sole includes a central longitudinal axis, a periphery, a front end located on said central longitudinal axis and on said periphery at the very front point of said lower sole, and a rear end located on said central longitudinal axis and on said periphery at the very rear point of said lower sole; a support bracket configured as a curvilinear confined band of a predetermined stiffness, the support bracket includes a flat top and a concaved bottom, wherein the flat top is fitted and fastened to a corresponding portion of the upper sole, whereas the concaved bottom is fastened to a corresponding portion of the lower sole such that said support bracket is fixed in relation to the upper sole, wherein the predetermined stiffness of the support bracket is chosen so that a position of said corresponding portion of the upper sole in relation to a position of said corresponding portion of the lower sole remains unchanged during the walking and running of the user, while the front end and the rear end are alternatively bent during the walking and running of the user; wherein: said lower sole is furnished with a plurality of slots, each said slot is cut from the periphery towards the central longitudinal axis and ending at a predetermined point of said lower sole; the lower sole further defines a central transverse axis; and said predetermined points of the lower sole are disposed along four straight lines extending through the predetermined points, wherein the four straight lines form a figure having a shape of rhombus with two acute angle vertices positioned on the periphery and on the central longitudinal axis at the front end and at the rear end respectively, and two obtuse angle vertices positioned on the periphery and on the central transverse axis, thereby providing for bending of said lower sole in a shape of circular arc during the walking and running of the user.