and use of rotating cutter-heads for planing one side of a piece of timber having been soon followed by the smoothing of two parallel sides at the same passage, it was not long before side-cutters were devised for smoothing or for matching one or two edges at the same pass. In working all four sides at once planing cutter-heads may be used in connection with matcher-heads, so as to form and finish at once all four sides of a board; four planers may be employed together, to square and finish all four sides of a joist or sill; or one or more moulding cutters may be used in connection with simple planingcutters. In many surfacing- and matching-machines the matcher-hangers are attached to a vertical adjustable frame, which, with the heads remaining upon the spindles, may be lowered under the line of the cylinder-bed. Matcher heads which move up and down with the bed save trouble and expense in separate adjustment. A desirable feature in matching-machines consists in having both the matcher-spindles and guides movable across the ma chines with one crank, so that the bed can be worn equally across its whole surface.
The shown in Figure 2 (pl. 14) is for tonguing and grooving short stuff. The two heads--one for tonguing and the other for grooving—are run on a steel arbor tinder the table, which latter is planed to take up the cut as the work passes over the cut ters. One of these cutter-heads works upon each side of the fence, which is rigid and has two idler rollers, to relieve it from friction. There are two feeding-rolls.
Feed of feed of machines may be (r) by hand over a plane bed; (2) by a travelling solid table, as in the Daniels machine; (3) by the Woodworth method of setting at right angles to the table of the machine friction-rollers, which draw the stock to the cutters; or (4) by a travelling bed like an endless apron. Some machines have two, and even three, of these means of feeding. The Woodworth type has a horizontal rotating cylinder, as in the ordinary dimension planer, but the feed is by pressure-rolls. Some machines have a combination of the Daniels and the Woodworth methods—that is, they have pressure-rolls for holding the work down to the platen in working by the Daniels system, and feed-rolls for planing "out of wind" or to a true plane. When not in use, the feed-rolls are moved back out of the way on slides. When used for surface-planing, the table is placed with its end under the cylinder and pressure-rollers, the feed-rollers being then moved into position. The platen or carriage has friction feed-works with change of speed, and the machine is so arranged as to plane while the carriage is running in either direction. Feed-rolls arc either " live " or "dead," live rolls being geared so as to have positive motion, and dead ones being mere ly guides. For feeding in two boards of unequal thicknesses side by side under a cutting-cylinder the upper feed-rolls 111 ay be divided in the middle, so that each end may work independently. Having swivelling-boxes for
the feeding-in rolls allows them to accommodate boards of uneven thick nesses and to give equal pressure to each side of a board without undue strain on gearing and screws. It is desirable to have a pair of feeding oat rolls for most planers; otherwise, where the last piece is spoiled it may be difficult to get it out of the machine. In double-cylinder planing-ma chines where side-matching is done there are three pairs of feed-rolls, two pairs before the cylinders and another after the matchers, carrying the lumber entirely through the machine and keeping it all the time in a straight line.
In an excellent smoothing-planer (fii. 7) there arc four driven feed-rolls connected by a train of expansion gears. The two lower rolls rise and fall with the bed and the upper ones are held in position by weights. The table is supported upon long inclines and raised and low ered by a screw and a hand-wheel. In sonic machines all bearings con necting- the feed-works are provided with ball-and-socket self-adjusting boxes.
For heavy surface-planing the machines are best belted at both ends. In some excellent makes the feeding-in roll has weighted pressure and the feeding-out roll has a spring, the latter roll being encased, to protect it from dust and shavings ( 151. 15, fig . 5). There are on each side of the cyl inder self-acting pressure-bars, the one in front rising and falling with the *feeding-in roller and always retaining the same relative position, yet yield ing to any inequalities in the surface of the material. The bed has friction rolls at its ends aid is raised and lowered in gibbed ways, to suit different thicknesses of lumber.
One method of weighting delivery-rolls (fig-. 2) for matching-machines throws the weight across the machine, the levers being connected, so that the leverage is more uniform and the pressure is sufficient to carry out the board without any additional weight, although the pressure-bar upon the upper cylinder is kept in proper place. There is a weighted pressure-bar before the cut and also a pressure-roller with springs, the tension of which may be controlled by a screw and a hand-wheel. The cylinder-frame, which carries the cutter, is gibbed to the sides, and the cylinder and pressure-bar adjust together to the thickness of the cut. In some of the best surface-planers the cylinder and feed-rolls raise and lower together, to suit the convenience of the material to be planed, always retaining, how ever, their relative position with respect to the bed-plate. Besides the friction-rolls both before and behind the cylinder, the table itself has friction-rolls at each end.