The process of deriving a way to explain the exact shape of the upper part of the modelled and computer using the same process

摘要

1414298 Boots &c DEFENCE SECRETARY OF STATE FOR 31 Jan 1973 [18 Feb 1972] 7513/72 Heading A3B [Also in Divisions B6 and G1] A method for deriving a 2-dimension pattern or template for sheet material to be made into a 3-dimensional article comprises the steps of selecting a plurality of points on a model having the shape of the 3-dimensional article, directly or indirectly measuring or calculating the distances between adjacent points, and deriving the pattern on a plane by successive triangulation computations using the said distances and starting from a chosen one of the points. As shown, a model M of a shoe is divided into a plurality of triangular areas by points such as Al, Bl, etc which are chosen such that the shape defined by the areas approximates to that of the surface of the model and the distances between adjacent points are measured by dividers or a wheeled measuring device such as may be used with maps, or the distances are calculated by determining the 3-dimensional co-ordinates of the points relative to a fixed frame of reference. The distances so measured or calculated are then marked on a plane surface and by a triangulation technique the 2-dimensional pattern is developed (Fig. 2). In an alternative embodiment, three sets of adhesive tapes are removably attached to the model M such that the tapes in any one set are at least approximately parallel and the tapes of different sets intersect. The points of intersection are marked on the tapes before the tapes are transferred to a flat surface. The distances between the points marked on the tapes are measured and from these measurements the 2-dimensional pattern is developed. The pattern may be used in cutting leather for making a shoe.