Endless Bed or “Farrar” Wood Surfacing Machine

This class of machine has a bed composed of slats which are connected together and driven by a chain.

Fig. 3174 represents an endless bed double surfacer constructed by the Egan Company. The upper cylinder may be raised or lowered to suit the thickness of the work. The front feed roll is in two sections, enabling two boards of unequal thickness to be planed simultaneously to an equal thickness. These rolls are held to the work by a leaf spring, as shown in the cut, the tension on the spring being adjusted by the screw at d, d serving as a check-nut.

A longitudinal section through the centre of the machine is shown in Fig. 3175. The spring s bears at each end on a block t, which carries the bearings for the feed roll. Feed roll m is held down by the screws e, e, acting on a rubber cushion or spring, and is provided with a scraper to clean it from dirt, etc.

The travelling bed is composed of slats s connected together by the chain shown, and resting upon slides a, a, supported by the girts b, b.

The chain is operated by the spur or sprocket wheel w, and is therefore pulled and not pushed, which tends to keep it under tension, and therefore rigid upon the top side.

The ends of the slide a, a are depressed so that the slats shall not tilt up at one corner above the level of the slide when in the positions denoted by s′.

The lower cutter head is carried in a sliding head or frame j, adjusted for height by the gears at h, which operate screw h, while the bed above it is adjusted by the gears at f. It is obvious that the bottom surface of this bed is set at the same height as the lowest point in the path of revolution of the cutting edges of the knives of the front cutter head or cylinder. The upper delivery roll n is provided with a scraper.