Finger jointing green lumber
First Claim
1. A method of finger jointing green lumber pieces wherein a first set of fingers is formed at one longitudinal end of each piece and a second set of fingers is formed at the other longitudinal end of said piece, said method comprising applying heat substantially solely to said first set of fingers to dry said first set of fingers and heat said one longitudinal end of each said piece in a first drying station, applying heat substantially solely to said second set of fingers to dry said second set of fingers and heat said opposite end of each said lumber piece in a second drying station, applying a thermosetting adhesive to one of said first and second sets of fingers, crowding said first set of fingers on one of said lumber pieces into a mating relationship with said second set of fingers on an adjacent lumber piece with said adhesive therebetween to form a joint in an assembly station, said one lumber piece and said adjacent lumber piece having their longitudinal axes substantially in alignment to form said joint, curing said adhesive in said joint by transferring heat energy applied to said one and said adjacent pieces in said first and second drying stations from said fingers to said adhesive in a time period so that said lumber pieces leave said first drying station said joint is formed in said assembly station and said adhesive is cured to secure said joint before migration of moisture from said pieces into said joint can interfere with said curing of said adhesive.
1 Assignment
0 Petitions
Accused Products
Abstract
Finger jointed lumber is produced from discrete green lumber pieces each formed with a first set of fingers on one end and a second set of fingers at the other end. The first set of fingers is dried by rapidly applying heat substantially solely through the first set of fingers in a first drying station. The second set of fingers is then rapidly dried in a second drying station. A thermo-setting adhesive is applied to the second set of fingers of each lumber piece while still hot and the second set of fingers on one piece and the first fingers on an adjacent lumber piece are mated and crowded together to form a joint. The adhesive is significantly cured by residual heat in the mating ends before significant moisture migrates back to the fingers from the bodies of the mating lumber pieces and interferes with the curing of the adhesive.
25 Citations
34 Claims
- 1. A method of finger jointing green lumber pieces wherein a first set of fingers is formed at one longitudinal end of each piece and a second set of fingers is formed at the other longitudinal end of said piece, said method comprising applying heat substantially solely to said first set of fingers to dry said first set of fingers and heat said one longitudinal end of each said piece in a first drying station, applying heat substantially solely to said second set of fingers to dry said second set of fingers and heat said opposite end of each said lumber piece in a second drying station, applying a thermosetting adhesive to one of said first and second sets of fingers, crowding said first set of fingers on one of said lumber pieces into a mating relationship with said second set of fingers on an adjacent lumber piece with said adhesive therebetween to form a joint in an assembly station, said one lumber piece and said adjacent lumber piece having their longitudinal axes substantially in alignment to form said joint, curing said adhesive in said joint by transferring heat energy applied to said one and said adjacent pieces in said first and second drying stations from said fingers to said adhesive in a time period so that said lumber pieces leave said first drying station said joint is formed in said assembly station and said adhesive is cured to secure said joint before migration of moisture from said pieces into said joint can interfere with said curing of said adhesive.
- 21. An apparatus for finger jointing green lumber pieces each having a first set of fingers at one longitudinal end and a second set of fingers at the other axial end comprising conveyor means for conveying said pieces through a first drying station having means for applying heat substantially solely to said first set of fingers to dry said first set of fingers and heat said one longitudinal end of each said piece as each said lumber piece is moved therethrough, a second drying station having means for applying heat substantially solely to said second set of fingers to dry said second set of fingers and heat said opposite end of each said lumber piece as each said lumber piece is moved through said second drying station along said conveyor means, means for applying a thermosetting adhesive to one of said first and second sets of fingers, an assembly station said conveyor means moving said lumber pieces past said means for applying adhesive and into said assembly station, said assembly station means for positioning said one lumber piece sand said adjacent lumber piece with their longitudinal axes substantially in alignment and means crowding said first said of fingers on one of said lumber pieces into a mating relationship with said second set of fingers on an adjacent lumber piece with said adhesive therebetween to form a joint, said second finger forming station, said second dryer station, said means for applying adhesive being positioned such that said conveyor means moves said lumber pieces from said first drier station to said assembly station in a time period so that significant curing said adhesive in said joint by transfer of heat energy applied in said first and second drying stations to said adhesive occurs to significantly cure said adhesive before significant migration of moisture from said pieces into said joint can interfere significantly with said curing of said adhesive thereby to secure said joint.
Specification