Panel Planing and Trying-Up Machine

This class of machine is employed for the production of true surfaces, and is now used upon much of the work that was formerly assigned to the Daniels class of planing machine. In this machine, as in the case of the Daniels planing machine, the work is secured to the table, which travels to carry the work to the feed.

Fig. 3187 represents a machine by J. Richards, in which a cutter head with skew cutters is employed, and a pressure roll is placed in front and at the back of the cutter head, the construction being as follows:

VOL. II. TRYING‑UP MACHINE. PLATE XXVI.

Upon the main frame are the slideways t, t′, upon which the cross-head or cutter head frame z is carried, the elevating screw s raising or lowering the frame z, to suit the thickness of the work. The cutter head c, whose driving pulleys are shown at p, p, is carried in frame z, which also carries the pressure roll in front of the cutter (the bearing for this roll being shown at r), and a similar roll behind the cutter. To the frame z are pivoted the pressure bars b, b′, weighted with weights w. These bars rest on the cross-heads y, whose pins p act on the bearing boxes of the pressure rolls.

The cutter head frame may be raised or lowered, for varying thicknesses of work, either by hand or by power. The hand movement is obtained from the hand wheel w, Fig. 3188, which operates bevel gears b′′ and b′, the latter being threaded to receive the elevating screw.

The power or belt motion for raising or lowering the cutter head frame is obtained from rope wheel w′, which receives motion from the guide pulleys shown in Fig. 3187. The wheel w′ drives its shaft by the friction cone of its bore, which is forced against the corresponding cone on the shaft by the hand nut l. The handle v, Fig. 3187, is for operating the upper guide pulley q, which acts as a belt-tightening pulley as well as a guide pulley, and the hand wheel t holds v in its adjusted position. When v is pushed downwards the rope (e) is loosened upon the pulleys, and both rope and pulleys remain idle.

The pulley that drives rope e is shown in Fig. 3189 at r.

The feed motions for the work table are shown in Fig. 3189, and the construction is such that for ordinary work the table has a quick return motion, while for heavy work the feed and return motions of the table are speeded alike.

The driving pulley b, Fig. 3189, for operating the feed mechanism, receives motion by belt connection from the countershaft, and drives the shaft on which are the bevel gears b and d, and from these gears the feed motion and quick return are derived, while from gear e and pulley r the cutter head may be raised and lowered by belt power as occasion may require. Beginning with the feed motion, the gear d drives gears e and f, which are a working fit on the shaft s. Between these two gears is the clutch r, r, which is operated by the handle shown in the perspective view, Fig. 3187, at v.

To operate the feed, clutch r is operated to engage gear e with the shaft s, upon which is the friction wheel m, which engages with the internal surface of the wheel or drum g, which drives the rope wheel a, which drives the rope for the work table traverse—wheel a and the rope being seen in the perspective view, Fig. 3187. The shaft n has bearing in a piece that is virtually a sleeve eccentric, because its bore is eccentric to its circumference; to this sleeve is attached a lug h′ to which the handle h, Fig. 3187, is bolted. Now suppose that handle h is depressed, and then g will partly revolve wheel g and cause it to engage with the friction wheel m, which will drive g, and therefore a.

Diametrally opposite to m is a friction wheel n, which is driven by the bevel gear c, and which is brought into or out of action with g by the eccentric action of sleeve g, it being obvious that when the sleeve g moves g in the direction of n, m is engaged and n disengaged from contact with g. Raising the handle h therefore places n in gear with g, which revolves it in the direction necessary to draw the work table on the back or return stroke.

The return motion of the table is more rapid than the feed motion because gear c is of smaller diameter than b, and n is larger than c and than m.

In the case of heavy work, however, the return motion may be made to have the same speed as the feed motion by simply moving the clutch r so as to engage wheel f with the shaft s.

The rope groove in the pulley a is waved as denoted by the dotted lines, and this prevents the rope from slipping, notwithstanding that the rope envelops but half the circumference of a. The wire rope from a operates a drum, in which are waved grooves for the table traversing rope which winds around this drum, and attaches to pins (k, Fig. 3187) carried in brackets at the ends of the table, and one of which is shown in Fig. 3187, at z.

The slack of the rope is readily taken up (as occasion may require) as follows:

The pin k, to which the rope is fastened, has at one end a squared head to receive a wrench to revolve the pin and wind up the rope, set screw l locking the pin after the rope tension is adjusted.

We have now to explain the method of holding the work, which is as follows:

The side frames forming the bed are bolted to the main frame and form the ways on which the work table travels. The table frame j, Fig. 3187, is provided with rollers, which rest on the upper surface of the bed and reduce the friction.

The table is made in convenient sections bolted to the table frame j, and at their points of junction the work-holding dogs are placed, the construction being shown in Fig. 3190, in which t′ is the end of one, and t′′ the end of another section of the table. Referring now to Figs. 3187 and 3190, upon the edge of the table are the abutment pieces a′, a′′, against which the work is pulled by the dog, which is operated by the screw, which is squared at its outer end to receive the handle m, Fig. 3187.

The rate of work feed is 30 feet per minute and the quick return motion is 60 feet per minute.