Machine for drying and butt-jointing wood veneer by continuous contact

Abstract

A machine for drying and butt-jointing unwound or sectioned wood veneer by continuous contact engagement comprises an effective drying and jointing zone, which includes an input conveyor and an output conveyor driven independently, each including an upper set and a lower set forming pairs of endless chains with pallets. The chains each have an active run and a return run; sprockets and roller means running on supporting guiderails drive said chains simultaneously. Pairs of said active runs face each other and compress the veneer therebetween and convey it in the longitudinal direction of the machine. The return runs are heated. First pressure means are positioned at the input of the effective zone, directly over the pairs of chains of the input conveyor; second pressure means are positioned at the output of the effective zone, directly over the pairs of chains of the output conveyor. Also input and output pressure means extend identically over the whole effective drying and jointing zone of the machine, said pressure means comprising respectively as many elastically deformable chambers as there are pairs of upper and lower endless chains in the associated conveyor. The chambers are supplied with fluid under pressure and each is arranged between a fixed upper support plate constituted by a girder, which is fastened to the machine and with which are if necessary associated lateral members for holding the chamber, and a flexible and relatively heavy layer, fixed in the longitudinal direction of the machine, having a width corresponding to that of the associated upper chain, bearing directly on said rollers of the active run of said chain and subjected to pressure from said deformable chamber pressing against said plate.