Method of making blind joints for precise positioning of members

Claim 1

In a metHod of butt joining the edges of pieces of material to provide a predetermined relationship between adjacent particular face surfaces of said pieces, wherein rectangular mortises of similar peripheral dimensions are cut into the confronting edges of the pieces to be joined to a depth less than the depth dimension of said pieces, and a spline is inserted therein, the improvement comprising: A. precisely positioning the major side wall of each said mortises a predetermined distance from said particular face surface of the respective piece of material; B. preparing a long strip of material with rectangular crosssectional dimensions slightly less than the cross-sectional dimensions of the mortise cavity formed when said confronting edges are in butting contact, a. the major faces of said strip being substantially flat and parallel yet including at least one longitudinal groove extending from end to end, and b. the walls of said groove terminating at the respective faces of the strip; C. cutting a spline from said strip of material, having transverse ends substantially perpendicular to the faces of said strip, and a length substantially equal to the length of said mortise cavity; and D. inserting said spline in said cavity along with an adhesive, to bind said pieces of material together.