The diameters of the eccentric gear-wheels e and s are equal; hence, c makes a revolution and the cross feed is actuated once for every cutting stroke. The swivel head h is bolted to the end of the slide or ram, as it is sometimes called, a, and is provided with a slide i upon which is a slider j, carrying an apron containing the tool post holding the cutting tool, the construction of this part of the mechanism being more fully shown in Fig. 1497. The eccentric gear-wheels r s are so geared that the motion of the slide a during the cutting stroke (which is in the direction of the arrow) is slower than the return stroke, which on account of being accelerated is termed a quick return. Various mechanisms for obtaining a quick return motion are employed, the object being to increase the number of cutting strokes in a given time, without accelerating the cutting speed of the tool, and some of these mechanisms will be given hereafter.

Referring again to the mechanism for carrying the cutting tool and actuating it to regulate the depth of cut in Fig. 1497, g is the end of the slide a to which the swivel head h is bolted by the bolts a b. The heads of these bolts pass into T-shaped annular grooves in g, so that h may be set to have its slides at any required angle. i is a slider actuated on the slide by means of the vertical feed screw which has journal bearing in the top of h, and passes through a nut provided in i. To i is fastened the apron swivel j, being held by a central bolt not seen in the cut, and also by the bolt at c. In j is a slot, which when c is loosened permits j to be swung at an angle. The apron k is pivoted by a taper pin l, which fits into both j and k. During the cutting stroke the apron k beds down upon j, but during the back stroke the tool may lift the apron k swinging upon the pivot l. This prevents the cutting edge of the tool from rubbing against the work during the return stroke.

Thus in Fig. 1498 is a piece of work, and it is supposed that a cut is being carried down the vertical face or shoulder at a; by setting the apron swivel at an angle and lifting the tool during the return stroke, its end will move away from the face of the shoulder. The slider i obviously moves in a vertical line upon slides m.

To take up the wear of the sliding bar a, various forms of guideways and guides are employed, a common form being shown in Fig. 1499. There are two gibs, one on each side of the bar, and these gibs are set up by screws to adjust the fit. In some cases only one gib is used, and in that event the wear causes the slide to move to one side, but as the wear proceeds exceedingly slowly in consequence of the long bearing surface of the bar in its guides, this is of but little practical moment. On the other hand, when two gibs are used great care must be taken to so adjust the screws that the slide bar is maintained in a line at a right angle to the jaws of the work-holding vice, so that the tool will cut the vertical surfaces or side faces of the work at a right angle to the work surface that is gripped by the vice.

To enable the length of stroke of slide a, Fig. 1496, to be varied to suit the length of the work, and thus not lose time by uselessly traversing that slide, e is provided with a T-slot as before stated, and the distance of the wrist pin (in this slot) from the centre of wheel e determines the amount of motion imparted to the connecting rod, and therefore to slide a. The wrist pin is set so as to give to a a rather longer stroke than the work requires, so that this tool may pass clear of the work on the forward stroke, and an inch or so past the work on the return stroke, the latter giving time to feed the tool down before it meets the work.

The length of the stroke being set, the crank piece e (for its slot and wrist pin correspond to a crank) is, by pulling round the pulley p, brought to the end of a stroke, the connecting rod being in line with slide a. The nut d is then loosened and slide a may then be moved by hand in its slideway until the tool clears the work at the end corresponding to the connecting rod position when nut d is tightened and the stroke is set.

Now suppose it is required to shape or surface the faces f and f′, the round curve s and the hollow curve c of the piece of work shown held in a vice chuck in Fig. 1500, and during the cutting stroke the slide a will travel in the direction of n in the figure, while during its return stroke it will traverse back in the direction of i. The sliding table w in Fig. 1496 would continuously but gradually be fed or moved (so much per tool traverse, and by the feeding mechanism described with reference to Fig. 1501) carrying with it the vice chuck, and therefore the work. When this feeding brought the surface of curve s, Fig. 1500, into contact with the tool, the feed screw handle in figure would be operated by hand so much per feed traverse, thus raising the slider, and therefore the tool, in the direction of l, and motion of the work to the right and the left of the tool (by means of the feed handle) would (if the amount of tool lift per tool stroke is properly proportioned to the amount of work feed to the right) cause the tool to cut the work to the required curvature. When the work had traversed until the tool had arrived at the top of curve s, the direction of motion of the feed-screw handle z in Fig. 1496 must be reversed, the tool being fed down so much per tool traverse (in the direction of m) so as to cut out the curves from the top of s to the bottom of c, the face f′ being shaped by the automatic feed motion only.

The feed obviously occurs once for each cutting stroke of the tool and for the vertical motion of the tool, or when the tool is operated by the hand feed-screw handle in Fig. 1496, the handle motion, and therefore the feed should occur at the end of the back stroke and before the tool again meets the work, so as to prevent the cutting edge of the tool from scraping against the work during its back traverse.

In this connection it may be remarked that by setting the apron swivel over, as in Fig. 1498, the tool is relieved from rubbing on the back stroke for two reasons, the first having been already explained, and the second being that to whatever amount the tool may spring, bend, or deflect during the cutting stroke (from the pressure of the cut), it will dip into the work surface and cut deeper; hence on the back stroke it will naturally clear the surface, providing that the next cut is not put on until the tool has passed back and is clear of the work.

Referring now to the automatic feed of the sliding table w, in Fig. 1496, the principle of its construction may be explained with reference to Fig. 1501, which may be taken to represent a class of such feeding mechanisms. a is a wheel corresponding to the wheel marked m in Fig. 1496, or, it may be an independent wheel in gear with the feed wheel. On the same shaft as a is pivoted an arm b having a slot s at one end to receive a pin to which the feed rod e may connect. f is a disk rotated from the driving mechanism of the shaping machine, and having a T-shaped slot g g, in which is secured a pin to actuate the rod e. As f rotates e is vibrated to and fro and the catch c on one stroke falls into the notches or teeth in a and causes it to partly rotate, while on the return stroke of e it lifts over the teeth, leaving a stationary.

The amount of motion of b, and therefore the quantity of the feed, may be regulated at either end of e; as, for example, the farther the pin from the centre of g the longer the stroke of e, or the nearer the pin in s is to the centre of b the longer the stroke, but usually this provision is made at one end only of e.

To stop the feed motion from actuating, the catch c may be lifted to stand vertically, as shown in dotted lines in position 2, and to actuate the feed traverse in an opposite direction, c may be swung over so as to occupy the position marked 3, and to prevent it moving out of either position in which it may be set a small spring is usually employed.

Now suppose that the tool-carrying slide a, Fig. 1496, is traversing forward and the tool will be moving across the work on the cutting stroke, as denoted by the arrow k in Fig. 1502, the line of tool motion for that stroke being as denoted by the line c a. At a is the point where the tool will begin its return stroke, and if the work is moved by the feeding mechanism in the direction of arrow e, then the line of motion during the return stroke will be in the direction of the dotted line a b, and as a result the tool will rub against the side of the cut.

It is to obviate the friction this would cause to the tool edge, and the dulling thereto that would ensue, that the pivot pin l for the apron is employed as shown in Fig. 1497, this pin permitting the apron to lift and causing the tool to bear against the cut with only such force as the weight of the apron and of the tool may cause. Now suppose that in Fig. 1503 we have a piece of work whose edge a a stands parallel to the line of forward tool motion, there being no feed either to the tool or the work, and if the tool be set to the corner f its line of motion during a stroke will be represented by the line f g. Suppose that on the next stroke the feed motion is put into action and that feeding takes place during the forward stroke, and the amount of the feed per stroke being the distance from g to h, then the dotted line from f to h represents the line of cut. On the return stroke the line of tool motion will be from h along the dotted line h k, and the tool will rest against the cut as before. Suppose again that the feed is put on during the return stroke, and that c c′ represents the line of tool motion during a cutting stroke, and the return stroke will then be along the line from c′ to b, from c to b representing the amount of feed per stroke; hence, it is made apparent that the tool will rub against the cut whether the feed is put on during the cutting or during the return stroke. Obviously then it would be preferable to feed the work between the period that occurs after the tool has left the work surface on the return stroke and before it meets it again on the next cutting stroke. It is to be observed, however, that by placing the pin actuating the rod e, Fig. 1501, on the other side of the centre of the slot g in f, the motion of e will be reversed with relation to the motion j of the slide; hence, with the work feeding in either direction, the feed may be made to occur during either the cutting or return stroke at will by locating the driving pin on the requisite side of the centre of g.

An arrangement by Professor Sweet, whereby the feed may be actuated during the cutting or return stroke (as may be determined in designing the machine), no matter in which direction the work table is being fed, is shown in Fig. 1504. Here there are two gears a and d, and the pawl or catch c may be moved on its pivoted end so as to engage either with a or d to feed in the required direction.

Suppose the slide to be on its return stroke in the direction of l, and f be rotated as denoted by the arrow, then the pawl c will be actuating wheel a as denoted by its arrow, but if c be moved over so as to engage d as denoted by the dotted outline, then with the slide moving in the same direction, c will pull d in the direction of arrow k′, and wheel a will be actuated in the opposite direction, thus reversing the direction of the feed while still causing it to actuate on the return stroke.

Since the feed wheel a must be in a fixed position with relation to the work table feed screw, and since the height of this table varies to meet the work, it is obvious that as the work table is raised the distance between the centres of a and f in the figure is lessened, or conversely as that table is lowered the distance between those centres is increased; hence, where the work table has much capacity of adjustment for height, means must be provided to adjust the length of rod e to suit the conditions. This may be accomplished by so arranging the construction that the rod may pass through its connection with wheel f, in the figure, or to pass through its connection with b.

Fig. 1505 represents a shaper that may be driven either by hand or by belt power. The cone pulley shaft has a pinion that drives the gear-wheel shown, and at the other end of this gear-wheel shaft is a slotted crank carrying a pin that drives a connecting rod that actuates the sliding bar, or ram, as it is sometimes termed. The fly-wheel also affords ready means of moving the ram to any required position when setting the tool or the work.

Fig. 1506 represents a shaping machine by the Hewes and Phillips Iron Works, of Newark, N.J. The slide or ram is operated by the Whitworth quick return motion, whose construction will be shown hereafter. The vice sets upon a knee or angle plate fitting to vertical slideways on the cross slide, and may be raised or lowered thereon to suit the height of the work by means of the crank handle shown in front. The vice may be removed and replaced by the supplemental table shown at the foot of the machine. Both the vice and the supplemental table are capable of being swivelled when in position on the machine. The machine is provided with a device for planing circular work, such as sectors, cranks, &c., the cone mandrel shown at the foot of the machine bolting up in place of the angle plate.

Holding Work in the Shaper or Planer Vice.—The simplest method of holding work in a shaper is by means of a shaper vice, which may be employed to hold almost any shape of work whose size is within the capacity of the chuck. Before describing, however, the various forms of shaper vices, it may be well to discuss points to be considered in its use.

The bottom surface a a, Fig. 1507, of a planer vice is parallel with the surfaces d, d′ and as surface a is secured to the upper face of the slider table shown in figure, and this face is parallel to the line of motion of the slide a, and also parallel with the cross slide in that figure, it follows that the face d is also parallel both with the line of motion of slide a and with the surface of the slider table. Parallel work to be held in the vice may therefore be set down upon the surface d (between the jaws), which surface will then form a guide to set the work by. The work-gripping surfaces b and e, Fig. 1507, of the jaws are at a right angle to surface a, and therefore also to d, therefore the upper surface of work that beds fair upon d, or beds fair against b, will be held parallel to the line of motion x of the tool and the line z of the feed traverse. Similarly the upper surfaces a, b of the gripping jaws are parallel to a a, hence they may be used to set the work true with the line of feed traverse. The sliding jaw, however, must be a sufficiently easy fit to the slideways that guide it to enable it to be moved by the screw that operates it, and as a result it has a tendency to lift upon its guideways so that its face e will not stand parallel to b or at a right angle to d. In Fig. 1508, for example, is a side view of a vice holding a piece of work w, the face f of the work being at an angle. As a consequence there is a tendency to lift in the direction of c. If the jaw does lift or spring in this direction it will move the work, so that instead of its lower face bedding down upon face d, Fig. 1507, it will lie in the direction of h, Fig. 1508, while its face parallel to f, instead of bedding fair against the face of jaw j, will lie as denoted by the line g, and as a result the work will not be held fair with either of those faces and the value of faces b, d and e in Fig. 1507 is impaired.

This lifting of the movable or sliding jaw is prevented in some forms of chuck, to be hereafter described, by bolts passing through which hold it down, but the tendency is nevertheless present, and it is necessary to recognise it in treating of chucking or holding work in such vices.

The work gripping face b, Fig. 1507, of the fixed jaw, however, is not subject to spring, hence it and the surface d are those by which the work may be set. The work, however, is held by the force of the screw operating the sliding jaw, hence the strain is in the direction of the arrow p in Fig. 1508, which forces it against the face of the fixed jaw. All the pressure that can be exerted to hold work down upon the surface d, Fig. 1507, is that due to the weight of the work added to whatever effort in that direction there may be induced by driving the work down by blows upon surface d after the jaws are tightened upon the work. This, however, is not to be relied upon whenever there is any tendency for the work not to bed down fair. It follows, then, that surface b of the work-gripping jaw is that to be most depended upon in setting the work, and that the surface that is to act as a guide at each chucking should be placed against this surface unless there are other considerations that require to be taken into account.

For example, suppose we have a thin piece of work, as in Fig. 1509, and the amount of surface bearing against the fixed jaw is so small in comparison to its width between the jaws that e would form no practical guide in setting the work. If then the edges of such a piece of work were shaped first the face or faces may or may not be made at a right angle to them, or square as it is termed. But if the faces were shaped first, then when the work was held by them to have the edges shaped there would be so broad an area of work surface bedding against the jaw surface, that the edges would naturally be shaped square with the faces.

In cases, therefore, where the area of bedding surface of the work against the faces of the jaws is too small to form an accurate guide and the work is not thick enough to rest upon the surface d, Fig. 1507, it is set true to that surface by a parallel piece.

If the work is wide or long enough to require it, two parallel pieces must be used, both being of the same thickness, so that they will keep the work true with the surface d.

Pieces such as p, Fig. 1510, are also used to set work not requiring to be parallel. Thus in figure are a number of keys placed side by side and set to have their edges shaped, and piece p is inserted not only to lift the narrow ends of the keys up, but also to maintain their lower edges fair one with the other, and thus insure that the keys shall all be made of equal width.

They are also serviceable to interpose between the work and the vice jaws when the work has a projection that would receive damage from the jaw pressure.

Thus in Fig. 1511 the work w has such a projection and a parallel piece p is inserted to take the jaw pressure. By placing the broadest work surface g against the fixed jaw the work will be held true whether the movable jaw springs or not, because there will be surface g and surface h guiding it.

But if the work were reversed, as in Fig. 1512, with the broadest surface against k, then if k sprung in the direction of c, the work would not be shaped true.

When the work is very narrow, however, the use of a parallel piece to regulate its height is dispensed with, and the top surface b of the jaw, in Fig. 1513, is used to set the work by. A line is marked on the work surface to set it by and a surface gauge is set upon the face b, its needle point being set to the line in a manner similar to that already explained with reference to chucking work in the lathe.

All work should be so set that the tool will traverse across the longest length of the work, as denoted by the tool in Fig. 1502, and the arrow marking its direction of traverse.

The general principles governing the use of the shaper vice having been explained, we may now select some examples in its use.

Fig. 1514 represents a simple rectangular piece, and in order to have the tool marks run lengthwise of each surface (which is, as already stated the most expeditious) they must be in the direction of the respective arrows. In a piece of such relative proportions there would be little choice as to the order in which the surfaces should be shaped, but whatever surface be operated on first, that at a right angle to it should be shaped second; thus, if a be first, either b or d should be second, for the following reasons.

All the surfaces have sufficient area to enable them to serve as guides in setting the work, hence the object is to utilize them as much as possible for that purpose. Now, suppose that surface a has been trued first, and if c be the next one, then the bedding of surface a upon the vice surface or the parallel pieces must be depended upon to set a true while truing c. Now the surfaces b and d may both, or at least one of them, may be untrue enough to cause the work to tilt or cant over, so that a will not bed fair, and c will then not be made parallel to a. It will be preferable then to shape a first and at the second chucking to set a against the stationary jaw of the vice, so that it may be held true.

The sliding jaw will in this case be against face c, and if that face is out of true enough to cant the work so that a will not bed fair, then a narrow parallel piece may be inserted between the sliding jaw and the work, which will cause a to bed fair. The third face should be face c, in which case face a will rest on one surface and face b will be against the fixed jaw, and there will be two surfaces to guide the work true while c is being trued. In this case also, however, it is better to use a parallel piece p, Fig. 1515, between the work and the sliding jaw, so as to insure that the work shall bed fair against the fixed jaw; and if necessary to bring up the top surface above the jaws, a second parallel piece p′ should be used.

Suppose now that we have a connecting rod key to shape, and it is to be considered whether the faces or the edges shall be shaped first. Now if the side faces are out of parallel it will take more filing to correct them than it will to correct the same degree of error in the edges; hence it is obviously desirable to proceed with a view to make all surfaces true, but more especially the side faces. As the set of the key while shaping these faces is most influenced by the manner in which the fixed jaw surface meets the work, and as an edge will be the surface to meet the fixed jaw faces when the side faces are shaped, it will be best to dress one edge first, setting the key or keys, as the case may be, as was shown in Fig. 1510, so as to cut them with the tool operating lengthways of the key; one edge being finished, then one face of each key must be shaped, the key being set for this purpose with the surfaced edge against the fixed jaw. As the width of the key is taper, either a chuck with a taper attachment that will permit the sliding jaw to conform itself to the taper of the key must be used (vices having this construction being specially made for taper work as will be shown hereafter), or else the key must be held as in Fig. 1516, in which k represents the key with its trued edge against the fixed jaw, at p is a piece put in to compensate for the taper of the key, and to cause the other edge to bed firmly and fairly against the fixed jaw.

The first side face being trued, it should be placed against the fixed jaw while the other edge is shaped. For the remaining side face we shall then be able to set the key with a trued edge against the fixed jaw, and a true face resting upon a parallel piece, while the other edge will be true for the piece p, Fig. 1516, to press against, and all the elements will be in favor of setting the key so that the sides will be parallel one to the other, and the edges square with the faces.

In putting in the piece p, Fig. 1516, the key should be gripped so lightly that it will about bear its own weight; piece p may then be pushed firmly in with the fingers, and the vice tightened up.

If there are two keys the edges and one face may be trued up as just described, and both keys k, Fig. 1517, chucked at once by inverting their tapers as shown in figure. But in this case unless the edges are quite true they may cause the keys not to bed fair on the underneath face, and the faces therefore to be out of parallel on either or both of the keys. If there are a number of keys to be cut to the same thickness it may be done as follows:—

Plane or shape first one edge of all the keys; then plane up one face, chucking them with one planed edge against each vice jaw, and put little blocks (a, b, c, d, Fig. 1518) between the rough edges; then turn them over, chuck them the same way and plane the other face, resting them on parallel pieces; then plane the other edges last.

In place of the small blocks a, b, c, d, a strip of lead, pasteboard, or wood, or for very thin work a piece of lead wire, may be used.

Cylindrical work may be held in a vice chuck, providing that the top of the vice jaws is equal in height to the centre of the work, as in Fig. 1519, a parallel piece being used to set the work true. When, however, the work is to be shaped at one end only, it is preferable to hold it as in Fig. 1520, letting its end project out from the side of the chuck. In some vices the jaws are wider than the body of the chuck, so that cylindrical work may be held vertical, as in Fig. 1521, when the end is to be operated upon.

Fig. 1522 represents a simple form of shaper or planer chuck, such chucks being used upon small planing machines as well as upon shaping machines.

The base a is bolted to the work table, and is in one piece with the fixed jaw b. The movable jaw c is set up to meet the work by hand, and being free to move upon a may be used for either taper or parallel work. To fasten c upon the work, three screws threaded through f abut against the end of c; f being secured to the upper surface of a by a key or slip, which fits into a groove in f, and projects down into such of the grooves in the upper surface of a as may best suit the width of work to be held in the vice; c is held down by the bolts and nuts at g.

The operation of securing work in such a chuck is as follows:—The screws both at f and at g being loosened, and jaw c moved up to meet the work and hold it against the fixed jaw b, then nuts g should be set up lightly so that the sliding jaw will be set up under a slight pressure, screws f may then be set up and finally nuts g tightened.

This is necessary for the following reasons:—The work must, in most cases, project above the level of the jaws so that the tool may travel clear across it; hence, the strain due to holding the work is above the level of the three screws, and the tendency, therefore, is to turn the jaw c upwards, and this tendency the screws g resist. A similar chuck mounted upon a circular base so that it may be swivelled without moving the base on the work table is shown in Fig. 1523. The capacity to swivel the upper part of the chuck without requiring the base of the chuck to be moved upon the table is a great convenience in many cases.

Fig. 1524 represents an English chuck in which the fixed jaw is composed of two parts, a which is solid with the base g, and d which is pivoted to a at f. The movable jaw also consists of two parts, b which carries the nut for the screw that operates b, and c which is pivoted to b at e. The two pivots e, f being above the surface of the gripping jaws c, d, causes them to force down upon the surface of g as the screw is tightened, the work, if thin, being rested, as in the case of the chuck shown in Fig. 1523, upon parallel pieces.

Fig. 1525 represents a chuck made by W. A. Harris, of Providence. The jaws in this case carry two pivoted wings a, b, between the ends of which the work c is held, and the pivots being above the level of the work the tendency is here again to force the work down into the chuck, the strain being in the direction denoted by the arrows.

Here the work rests on four pins which are threaded in the collars h, so that by rotating the pins they will stand at different heights to suit different thicknesses of work, or they may be set to plane tapers by adjusting their height to suit the amount of taper required. The spiral springs simply support the pins, but as the jaws close the pins lower until the washer nuts h meet the surface of recess i.

Figs. 1526 and 1527 represent Thomas’s patent vice, which possesses some excellent conveniences and features.

In Fig. 1526 it is shown without, and in Fig. 1527 with a swivel motion. The arrangement of the jaws upon the base in Fig. 1526 is similar to that of the chuck shown in Fig. 1522, but instead of there being a key to secure the piece f to the base, there is provided on each side of the base a row of ratchet teeth, and there is within f a circular piece g (in Fig. 1528) which is serrated to engage the ratchet teeth. This piece may be lifted clear of the ratchet teeth by means of the pin at h, and then the piece f may be moved freely by hand backwards or forwards upon the base and swung at any required angle, as in Fig. 1528, or set parallel as in Fig. 1527; f becoming locked, so far as its backward motion is concerned, so soon as h is released and g engages with the ratchet teeth on the base. But f may be pushed forward toward the fixed jaw without lifting h, hence the adjustment of the sliding jaw to the work may be made instantaneously without requiring any moving or setting of locking keys or other devices.