In the 26-in. double-surfacing machine shown in Fig. 3, the cylinders are large and slotted, and rim in yoke boxes. There is a bonnet chip-breatker, and a complete set of pressure bars which have every desirable adjustment. The lower cylinder may be set for any desired cut, and the end of the bed will swing down to admit of easy access to the head for sharpening or setting the knives. The bed is raised and lowered on four screws by hand or by power ; and when power is used, an adjustment of 8 in. is accomplished in one minute. When set to proper thickness, the lower cylinder, while firmly clamped to the bed, is also clamped to the sides of the frame. The gears on the feed rollers are of about double the diameter of the latter, giving great leverage. Each pair of feed-roll boxes is connected in a yoke frame to avoid the possibility of cramping, and all links are hung on boxes instead of on roll shafts. The feed is driven direct from the top cylinder, through two feed shafts provided with cones giving four changes of speed.
The Smith Double SUr.farer. —In a 26-in. cabinet double-surfacing planer made by the H. B. Smith Nachine Co., there are some features which are absent from some others of the same general type. Thus, for undersurfacing, the bed is supported on four screws. one under each nut of the cutting cylinder, and the curved pressure bar over the underhead is very rigid, thus giving stiffer and truer work with the undersurfaeing head than would be the case without these features. The feeding-in rolls have a weighted equalizing bar to give a parallel lift and prevent cross strain on the gears. There is a spring device to overcome the inertia of the weighted rolls when extra thick stock is being entered, and to lessen liability of breaking the weight straps or bars.
The Goodell £ Waters Planer.—An 8-roll timber-planer made by Goodell & Waters, and which will surface up to 26 in. wide, and to 16 in. thick, and square timber up to these dimensions, will also, by the use of a centre guide, surface two pieces on top, bottom, and outside edge, each up to 11 in. wide, at one operation. The feed rolls are driven by a belt, passing around idlers in such a manner as to permit a greater range of thickness of material fed than is possible by gears. The second bottom roll is yielding, and weighted so as to raise and follow the irregularities of the lumber.
Flooring Board Planers.—A demand having arisen for machines with a great capacity for planing flooring boards, there has been produced a number of machines characterized by very fast feed and great capacity. Another type in which the limit of feed has not been reached, is duplex, planing and matching two separate boards at one operation, so that its capacity is from 4,000 to 6,000 ft. per hour. Its work consists in not only planing both sides, but tonguing and grooving both edges and working a bead or rabbet on both the boards. The machine has two short upper cutting-cylinders, axially in line, and two duplex sets of feeding-in rolls, also axially in line, and driven by gearing. The pressure bars before
and after the cut of the upper cylinders are duplex ; and the under cylinder has also duplex pressure bars, each of which is adjustable vertically independently of the other, or both may be adjusted together. The upper cylinders raise and lower simultaneously or independently, as desired, so that the machine may be used as a duplex machine working two boards at once, or as a single flooring machine working only one board. The matching works are duplex and work the edges of both boards at one operation ; being adjustable to snit the width of lumber from the face side of the machine, The lumber platen has a duplex board guide, and an automatic edge feed for carrying the lumber to the feed rolls, moving the lumber in a straight line to the first receiving feeding roils, even if it is warped or crooked. The feed is comparatively slow, thus making the stuff more free from cylinder marks than if capacity was got by fast speed, instead of, as in this case, by having two complete sets of cutters and working two boards at once at comparatively slow feed speed.
In some makes of fast flooring machines the beading cutter heads and matcher heads are placed between the first and the second pairs of rolls. The object in taking the beading knives from the surfacing cutter heads is to have on each head four knives instead of two, which of course helps to do rapid work. If they were put after the eater heads instead of before them, the bead would be more apt to be ragged than if it was worked first and any trifling splintering or roughness effaced by the surfacing cutters; such defects coming, out more strongly when the work is painted than while it remains uncovered. It is also claimed that when the matching heads are placed after the surfacing cutters, and the board held as firmly as it should be, to assure good matching and beading, one pair of smooth rolls cannot feed the board to or deliver it from the machine; and also that if the gauges under this arrangement arc set too tight when matching, the lumber will show the marks, which is very objectionable. A properly constructed and operated flooring-board machine should deliver work at the rate of 100 ft. per minute; most of those now at work do only from 50 to 60 ft. Messrs. C. B. Rogers & Co. have brought out during 1891 a planer and matcher, to work 15 in. wide and 6 in. thick, feeding from 25 to 110 ft. per minute, In a matching and jointing machine made by the Lane Manufacturing Co. there is an adjustable roll which holds the board firmly upon the beading head, preventing springing or trembling while the end of the board is passing from the feeding-in to the feeding-out rolls; and the beading head is fitted with saw-teeth knives which remove fuzz from the edge of the bead.