METHOD FOR OBTAINING DEVELOPMENT OF SHOE LAST SURFACE Russian patent published in 1997 - IPC

FIELD: shoe industry, in particular, designing of shoes by conventional developments of last side surface. SUBSTANCE: method involves marking geodetic lines extending from most projecting point of toe to most projecting point of heel on inner and outer surfaces of last, so that geodetic lines intersect points corresponding to centers of bundles and spaced one from another by distance equal to 1/3 of distance between last trace rib and mid portion of ridge along bundle lines; applying transverse auxiliary lines extending perpendicular to geodetic lines to obtain constructive line grid; subdividing surface of complex geometric body of last into portions by extreme sections: widest portion of heel, mid portion of foot, outer bundle, inner bundle, and conventionally approximating these portions with more simple geometric bodies of rotation: first portion extending from most projecting point of heel to widest portion of heel - with two truncated cones connected with their large bases and cylinder positioned above them, and subsequent portions - with cylinder, truncated cone, cylinder and spherical part, respectively; spreading obtained grid of constructive lines and group of geometrical bodies of rotation mated with their faces in one plane relative to geodetic lines to obtain flat pattern of conventional development of last surface; registering lacking or excessive area (overlap or noncoincidence of areas of separate developments depending on their shape) at joints of developments of geometric bodies of rotation; measuring main characteristics of approximating bodies of rotation (radii, generatrices, heights) to determine the values of correction by formulas obtained on the base of geometric laws; marking obtained values on flat pattern of conventional development of last side surface. EFFECT: increased efficiency and simplified method. 8 dwg, 1 tbl