METHOD OF FORMING FINGER JOINTS IN WOOD BLANKS Russian patent published in 2013 - IPC B27F1/00 

FIELD: process engineering.

SUBSTANCE: invention relates to woodworking industry. Blanks are selected qualitatively. Blanks are faced and located. Finger joint elements are shaped. Blanks are machined. Glue is applied on surfaces to be jointed. Blanks are jointed together, locked and cured. Finger joint elements are formed as follows: Blank 2 is reduced to impress punch 1 in blank end face along wood fibres to required depth 6 of eyes. Bulged zone 3 of depth 7 is formed under said eye. Punch is withdrawn from blank to remove crimper from blank. Punch profile corresponds to shape of finger joint elements. Temperature of shaping finger joint elements corresponds to that of shop floor without wood and tool heating. Moisture content of wood makes 6-18%. Crimping force makes 300-1400 N. Punches feature shape of rectangular tenons with tenon thickness, eye width 5, tenon spacing, and eye depth. Punch pressure 4 on blank makes 30-100 MPa. Punch displacement speed makes 5-120 m/min. Blanks are assembled in finger joint in length or angular finger joint. Finger joint is invisible in surface and/or in edge.

EFFECT: power savings, higher quality, decreased consumption of glue.

10 cl, 3 dwg