OTHER FORMS OF TENONING MACHINES.—Blind-scat Tenoning Machines.— In the blind-slat tenoning machine shown in Fig. 9 the tenons arc produced by saw-like cutters borne on a horizontal mandrel, which is parallel with the slat. The slat is fed in to a stop-gauge through a rotating chuck, and then brought. down upon the rotating cutter, which cuts and divides two tenons at once with one cutter-head at one operation. As the slat rotates, a cylindrical form is given to the tenon, and the latter is central in the width of the slat. The cut being made from the outside to the center, tearing or splitting of the wood is done away with. Releasing the table stops the chucks, and allows the slat to be fed forward to the gauge.
The slat tenoner shown in Fig. 10, and made by Rowley & Hermance, has a self-centering device for holding the slats, thus making a tenon in the center of the slat width, although, if desired, it may be made nearer one edge than the other. The slat is firmly held when being cut, and is not released until the tenon has been fitted and the slat cut off. The slat is moved to the saws, and two tenons cut by one motion of the lever. There is a stop to determine the length of the slats. A self-feed blind-slat tenoning machine, made by the II. B. Smith Machine Co., has a vertical iron column bearing at its upper end a rotating gear-wheel, through the cen ter of which the blind slat is fed. The slat is passed, while rotating, by a tenoning saw, which works away the stock so as to leave a cylindrical tenon in the center of width and thickness of the slat, the slat going on until it strikes a rear stop, which may be adjusted to make any length of slat desirable up to,17 in.
There is a front guide stop by which the full length of stock may be gauged in length and tenoned ; so that if either the stock or the last piece is short, the piece may be turned about and gauged from the front; and if the piece is too short to handle, a plunger on the front stop will push it within the jaws of the clamp, thus preventing waste from inability to feed short pieces.
The stock is undamped OD the deliver ing side of the machine or saws. doing away with the liability of two clamps getting out of alignment and doing inaccurate work, or of the finished piece getting caught against the stops. The clamp, which will hold stock of any length, rotates by power, coming in contact with a spring stop each round, where it remains in position until released by raising or lowering the hand lever. which moves the saws to or from the slat in the act of making or dividing the tenon. When this lever is released, the saws auto matically resume a position which leaves the clamp with the slat central, so that when the slat is pushed forward it cannot come in contact with the saws.
Dovetailing machines, which are really tenoners, are of several classes. In the most common, the cutter is of the ordinary fly type, cutting with its side and end, and producing both the mortise and the tenon. In some of these, for work in drawer fronts and similar pieces, the cutting tools are in sliding frames, adjustable for the length of the pin or tenon ; the carriage bearing the material is moved vertically and lengthwise, automatically, cutting at each movement of the crank wheel a pin and a recess, cutting and feeding hi both directions. The material is supported by a eomb.like arrangement, between the teeth of which the cutters pass to their work. This being a species of tenoning which demands special treatment, one of the machines for effecting a class of work which may be classed as dovetailing, and in some senses as tenoning, will be found described under the head Of DOVETAILING.