Tenoning Machines

In tenoning machines, the lengths of the pieces usually operated upon render it necessary that the work should lie horizontally upon the table, while the shortness of the tenon makes an automatic feed unnecessary.

The revolving heads carrying the cutters in tenoning machines are so constructed that the cutting edges of the cutters are askew to the sides of the heads, but so set as to produce work parallel to the axis of the cutter shaft.

This causes the cutting action to begin at one end of the cutter edge, and pass along it to the other, which enables a steady hand feed, and reduces the amount of power required to feed the work.

Fig. 3227 represents a cutter head for a tenoning machine, a, a and b, b being the cutters and c, c, d, d spurs which stand a little farther out than the cutter edges, so as to sever the fibre of the wood in advance of the cutter edges coming into action, and thus preserve a sharp shoulder to the tenon, and prevent the splitting out at the shoulder that would otherwise occur.

To bring the outer edge of the shoulder in very close contact with the mortised timber, the cutters are for some work followed by what is termed a cope head, which is a head carrying two cutters bent forward as in Fig. 3228, to make them cut very keenly, as is necessary in cutting the end grain of wood.

The cope head undercuts the shoulder, as shown at a, a, in Fig. 3229, which is a sectional view of a mortise and tenon.

Fig. 3230 represents a tenoning machine for heavy work, constructed by J. A. Fay & Co., adjusted for cutting a double tenon, the upper and lower heads revolving in a vertical plane, and the middle head in a horizontal plane.

a is a vertical slideway for the heads c, d, carrying the shafts for the cutter heads a, b. At b is the hand wheel for adjusting d, and at e that for adjusting c. The pulley d is for driving the cope heads, one of whose cutters is seen at c. The work carriage h is provided with rollers which run on the slide on k, and is supported by the arm i, which rises and falls to suit the cross motion of h. The fence g, for the work, is adjustable by means of the thumb nuts.