Design of multipoint anti-kickback fingers for woodworking machines

The main factors involved in the design of anti-kickback fingers is in the contact angle at the point of contact with the wood, the radius of wear at this point, and the roughness of the wood with which it comes in contact. B ecause of the wide range of wood thicknesses that pass through a machine, c onventional single-point fingers cannot come in contact with the wood at an gles appropriate for each of these thicknesses. The use of many points ensu res that a suitable contact angle is achieved for all thicknesses of wood f or each machine. The results of two anti-kickback finger design projects, o ne for a machine in the furniture industry and the other for a machine in a sawmill resulted in a new analytical design method for efficient multipoin t anti-kickback fingers. This new approach, as opposed to the conventional graphical method, was validated by comparing three specific cases; the adva ntages of the new method are illustrated in an example of the redesign of m ultipoint anti-kickback fingers.