Combination power- and hand-feed surface-planers (fig. 7), which are desirable in shops having a wide range of work, may be arranged to plane under the cylinder by feed-rollers, or the bonnet and pressure-bar may be removed and the end table raised to the proper height by a screw and a hand-wheel, so that planing may be done by hand-feeding over the cylin der. As arranged for hand-plarting the platens cover the cylinder and feed rolls, and no obstruction is presented.
advantage of the endless-bed planer is that it can feed lumber into the machine under more varying conditions than a roll-machine. It will take iu and properly handle, if of suitable design and construction, lumber that is hard or soft, green or dry, wet or icy. It will work warped or icy material which no other planer will carry in. It is usully built with but one cutting-cylinder, although some times with two or more, or it may be provided with Daniels cutters. Some endless-bed machines raise the bed, others the cutter-head. Moving the head is a convenience, particularly when necessary to plane long heavy stuff. In very large machines (pl. 15, fig. i) the cylinder is stationary, which makes it permissible to have the counter-shaft either on the floor or overhead.
One objection to the ordinary endless-bed machines is that there are two shoes for the travelling bed to pass over, leaving between them ,a space of io or 15 inches, and thus giving the lags no support between the shoes. The lags also are apt to cut and indent the worked lumber, and to gather gum and flue dust upon their surfaces, causing irregularity in the lumber being planed; or a knot or a chip will carry around on the bed and raise the lags into the knives. To overcome the trouble of the unsup ported bed end one maker constructs the bed of a series of ribs placed diagonally across the whole width of the machine (figs. 3, 4), thus sup porting the lag its entire length. This secures uniformity of lag wear and gives a weight of iron to serve as an anvil for the blow of the knives; it also prevents accumulations of dirt or gum upon the lags. The bed is lubricated by a roll covered with sheepskin with the wool on, and in such position that it revolves with the travelling bed. From it runs a perforated pipe connected with an oil-pocket.
To enable two or more pieces of different thicknesses to be planed at once on an endless-bed machine, instead of having a "broken" roll—that is, one broken in its length and having a centre-bearing, which must of necessity be small—the rolls may be hung on an eccentric shaft made out of a steel forging. The rolls revolve upon the shaft, which swings in boxes
at each end. The shaft, turning in the box, accommodates itself to any irregularity or thickness in the lumber.
The Surfacer (figs. 8, 9) has the line of the bed fixed, the upper cylinder and the pressure-bar over the lower cylinder bars adjusting together to the thickness of the lumber. Both the bar and the lower cylinders may be raised or lowered while running. The rolls and pressure-bars arc divided, so that one wide board or two boards of unequal thickness may be worked. For dressing on all sides large car sills and timber an excellent machine 16, i) has its bcd fixed to the cylinders, and adjustable rolls to suit the various thicknesses of material. There is an endless-bed feed, besides which there is a pair of large feeding-rolls expansively geared, to draw the material from the side cutters. The material is worked first upon its upper face, then upon its sides, and filially upon the lower surface.
Dimension and S (pl. r4) illustrates a vcry useful machine which combines the features of an endless-bed dimen sion-planer and a jointing-machine, and which will finish on three sides and work two pieces at once. The feed is of the endless-bed type; the upper cylinder is in a raising-frame, the lower cylinder is in the main frame, and there are two side-heads, which move across the machine. The side heads are removable from their spindles, to permit of wide surfacing, and their frames are separately adjustable across the machine by a long screw attached to each. The pressure-bar, which presses on the work after the cut of the upper cylinder, is adjustable, and that over the lower cylinder is adjustable vertically, independently of its being raised in connection with the upper cylinder. Time bed is always in one position. Over the travel ling bed are two independent or broken rollers, under which two boards of unequal thickness may be placed and by which they may be fed in at the same time. There are two independent pressure-bars before the cut of the upper cylinder and a pressure-roller after its cut, to retain the boards in position after passing the cylinder.