A NEW KIND OF END-GLUED JOINT FOR THE HARDWOOD INDUSTRY

Abstract.-A method has been developed for end- and edge-gluing short pieces of high-value hardwood lumber into long panels, using a curved end joint we call SEM (Serpentine End Matching). Panels containing SEM end joints are aesthetically pleasing and are suited for exposed applications such as in finished furniture. Furniture plants generate large quantities joints. The curved line of the SEM joint is of short leftover pieces of wood. End-jointing less visible than the straight lines of the butt these short pieces to make longer lengths al- joint or finger joint (fig. 1). lows greater utilization of raw materials. Some Curved end joints cannot be made with furniture companies use square butt joints or conventional end-jointing equipment. How-finger joints to do this. Almost all this mate- ever, use of tape-controlled or optical-head-rial is being used in core stock and unexposed controlled routers eliminates the machining upholstered-furniture parts because these con- obstacles. ventional types of joints are considered aes-thetically unpleasing for exposed applications. Producing a Tight Researchers a t the Forest Products Mar- Curved End Joint keting Laboratory have developed curved end joints called SEMI (Serpentine End Match- In end jointing, tightness of fit is essential-ing) for exposed applications. Curved end Though conventional k g e r joints Or butt joints follow the pattern of the wood joints can be Illade easily with properly pre-better than the conventional butt or finger pared cutterheads, curved end joints present another problem. The curved path of the cut-terhead must be controlled precisely. LUMBER PANELS WITH SERPENTINE JOINTS. Hugh W. Reynolds, Philip A. Ar-n, and Wesley R. A curved end joint cannot be made sim-Martin. Patent pending at the U. S. Department of ply routing a curved path across a piece o