Modern Machine-Shop Practice Part 218

[Ill.u.s.tration: Fig. 3180.]

The ap.r.o.n M' in front of the under cutter S (Fig. 3180) is easily dropped to M" by loosening the nut R' and releasing the bolt T' so as to allow the ap.r.o.n M' to drop.

This enables the operator to have free access to the under cutter for sharpening knives, etc. _z'_ is the bed plate over which the lumber pa.s.ses before it reaches the under cutter.

[Ill.u.s.tration: Fig. 3181.]

[Ill.u.s.tration: Fig. 3182.]

A planing and matching machine designed and constructed by Messrs.

London, Berry and Orton is represented in Fig. 3181. In this machine the upper surface of the board is surfaced first, and the matching second, the under surface being operated upon the last. The method of suspending the upper feed rolls of this machine is shown in Fig. 3182, in which A is an upper and B a lower feed roll. The upper roll A is suspended by the link C, which is supported by the link D, and also by link E, these three links forming a parallel motion which guides A in a vertical line.

At F (which is fast to E) is a bearing for the screw G, and the pair of bevel gears _g_ that drives it. This screw threads into the nut H on the rod I, which receives the pressure of the bar J and weight K.

The lower feed rolls being larger in diameter gives them increased grip on the work, and gives it a better base, and also makes it enter and leave the rolls easier.

Each matcher bracket is fitted with a screw by which it can be moved at will across the machine, and by turning one other screw with the same wrench that moves the others, both brackets are firmly set to the slide and all screws held firmly. There are three changes of feed. The top cutter head is provided with improved pressure bars, which are set to or from the head by means of a double eccentric, which, while they can be set at any desired distance from the knives, limits their movement when moved towards them, rendering it impossible to get them into the cutters.

TIMBER PLANER.

The term timber planer implies that plain knives only are used in the machine, which is therefore intended for producing plane surfaces. It also implies that the machine is designed for heavy or large work, such as is found in s.h.i.+p yards, bridge construction or car works, etc., etc.

In such work the cuts taken by the machine are sometimes very heavy, and as a result the feed works of the machine require to be very powerful and positive.

Fig. 3183 represents a timber planer designed and constructed by J. S.

Graham & Co., to plane all four sides of the timber at one pa.s.sage through the machine.

The timber pa.s.ses through three pairs of feed rolls before reaching the first cutter head, which planes the bottom surface.

It then pa.s.ses to the side heads, which dress both sides simultaneously, and then pa.s.ses beneath the cutter head that finishes the upper surface, and is finally delivered from the machine by a pair of delivery rolls.

The work is pa.s.sed over roller B, the fence or gauge being shown at B'.

1 and 2 are the first pair of feed rollers, _a_ and _b_ being merely adjustable intermediate wheels, which by means of the pieces _c'_, _b'_, may be set so as to connect rollers 1 and 2 together, whatever their distance apart may be, or in other words whatever the thickness of the work may be.

[Ill.u.s.tration: Fig. 3183.]

From 1 and 2 the work pa.s.ses to the second pair of feed rolls 3 and 4, _c_ and _d_ being the intermediates.

Similarly 5, 6, 7 and 8 are feed rolls, and _e_, _f_, _g_, _h_ intermediates. The first head is shown at K', the side heads at H, and the last head at I', the latter being carried on a sliding head J, which is secured in its adjusted position by nuts I. On the side of the frame D on which J slides is a graduated index to denote the adjustment of the head I'.

[Ill.u.s.tration: Fig. 3184.]

The construction of the parts in immediate connection with the front cutter head is shown in Fig. 3184. N is the frame corresponding to N in Fig. 3183, the rolls 5 and 6 also corresponding in the two figures.

Upon N is a slide S having an arm G, carrying the roll G', which holds the timber down to the cut of the cutter head K'. The pressure of roll G' to the work is given through the medium of the rod _a'_, which receives the pressure of the equalizing bar _x_, Fig. 3183.

The bottom surface of the timber pa.s.ses over the bed plate U, Fig. 3185, which raises and lowers with the lower feed rolls, being connected by the screw _i_, Fig. 3184, to the bearing box of feed roll 6.

All the lower feed rolls are operated simultaneously by means of the rod _l_, having for each lower feed roll a worm, driving a worm wheel _l'_ on a screw threaded into a hub _m_ in each feed roll bearing; the crank for operating _l_ is seen at P, Fig. 3183.

[Ill.u.s.tration: Fig. 3185.]

The pa.s.sage of the timber through the machine is continued in Fig. 3185, in which it is seen that after the lower surface of the timber has been planed it pa.s.ses from the cutter head K' to a bed plate V and is thus supported by a flat and true surface while the side cutter heads plane the two sides, one of these side heads being shown at H. The side heads are carried in hangers, one of which is shown at _p'_. It is gibbed to the under cutter frame U' by the sliding gib _x_, the left hand head H being moved across the frame by the screw _f'_. The hanger is held at the bottom by the gib _t_ and the cross tie _t'_. _p_ is the pulley for the side head H, the end wear of whose shaft is taken up by the adjusting screw _s'_, _r'_ being a leather washer, and _r_ the end of the shaft.

[Ill.u.s.tration: Fig. 3186.]

The top box H' moves across the machine in the slideway _b"_, Figs.

3186, _a"_ being a part of the box H'.

Upon leaving the side heads the timber will have been planed on three sides and the side surfaces dressed to a right angle with the bottom surface.

It is then guided to the upper cylinder as follows:

The friction rolls K, K are to relieve the bed A" from the pressure due to the feed roll Z' and the roll J', which holds the timber after it has left the cutter I', and thus prevents it from vibrating. After leaving the pressure roll J', the timber pa.s.ses under the sc.r.a.per _d'_, Fig.

3183, and thence to the delivery roll 7, which is held down by the weight L, in connection with the lever L'.

By means of this construction all the cutter heads act upon the timber within the short distance of 22-1/2 inches, while the side heads act within 8-1/2 inches of the under cutter. This is desirable, being conducive to the production of true work, which it is more difficult to produce in proportion as the cutter heads are wider apart. This machine will joint as narrow as 2 inches, and plane as thin as 3/4 inch.

The upper cylinder I', Fig. 3183, is adjusted for height or thickness of cut by means of the screw _f_, and is locked in its adjusted position on D by the nut I.

The feed is started or stopped by operating the hand wheel _o'_.

The upper rolls are raised or lowered simultaneously by power, by means of the shaft _s_, and the bevel gears _r_, which operate the screw _a'_.

The upper cylinder is driven by belt from the pulley Q, the under cylinder from Q' (both these cylinders being driven from both ends). P'

is the driving pulley for the feed belt, which pa.s.ses to N', which, through K" and Y', drives Y, which drives the feed rolls.

The machine will feed from 25 to 60 feet per minute.

PANEL PLANING AND TRYING-UP MACHINE.

This cla.s.s of machine is employed for the production of true surfaces, and is now used upon much of the work that was formerly a.s.signed to the Daniels cla.s.s 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:

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.

[Ill.u.s.tration: _VOL. II._ =TRYING-UP MACHINE.= _PLATE XXVI._

Fig. 3187.]

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.

[Ill.u.s.tration: Fig. 3188.]