Fig. 1590Fig. 1590.
Fig. 1590.
The graduations of the degrees of a circle for setting over the swing framef, as is necessary when planing surfaces that are at an angle to the bed and to the cross slide, are marked on the face of the saddle, and the pointer (f,Fig. 1578) is fastened to the edge of the swing frame. When the swing frame is vertical the pointer is at 90° on the graduated arc, which accords with English practice generally. In American practice, however, it is customary to mark the graduations on the edge of the swing frame as inFig. 1590, so that the pointer stands at the zero pointowhen the swing frame is vertical, and the graduations are marked on the edge of the swing frame as shown, the zero lineobeing marked on the edge of the saddle.
In the English practice the swing frame is supposed to stand in its neutral or zero position when it is vertical, and all angles are assumed to be measured from this vertical zero line, so that if the index point be set to such figure upon the graduated arc as the angle of the work is to be to a vertical line, correct results will be obtained.
Fig. 1591Fig. 1591.
Fig. 1591.
Fig. 1592Fig. 1592.
Fig. 1592.
Thus inFig. 1591(which is fromThe American Machinist) the pointer is set to 40° and the bevelled face is cut to an angle of 40° with the vertical face as marked. But if the head be graduated as inFig. 1592, the face of the planer table being taken as the zero lineo, then the swing frame would require to be set over to 30°out of its normal or neutral vertical position as is shown in figure, the bevelled face being at an angle of 50° from a vertical, and 40° from a horizontal line, hence the operator requires to consider whether the number of degrees of angle are marked on the drawing from a zero line that is vertical on one that is horizontal.
Referring again toFig. 1588the slots for the tool post extend fully across the apron, so that the tool posts may be set at any required point in the tool-box width, and the tool or tool holder may be set nearer to the edge of the tool box than is the case when fixed bolts, as inFig. 1590, are used, because these bolts come in the way.
Fig. 1593Fig. 1594Fig. 1593.Fig. 1594.
Fig. 1593.Fig. 1594.
This is mainly important when the tool is required to carry a deep vertical cut, in which case it is important to keep the tool point as close in to the holder as possible so that it may not bend and spring from the pressure of the cut.
The tool or holder may be held still closer to the edge of the head, and therefore brought still closer to the work, when the apron embraces the outside of the tool box, as was shown inFig. 1585, and referred to in connection therewith.
Fig. 1595Fig. 1595.
Fig. 1595.
Fig. 1596Fig. 1596.
Fig. 1596.
A sectional side view and a top view ofFig. 1588through the centre of the head is given inFigs. 1595and1596, exposing the mechanism for the self-acting feed traverse, and for the vertical feed. For the feed traverse the feed screw (m,Fig. 1588) passes through the feed nutn. For the vertical feed the feed rod (n,Fig. 1588) drives a pair of bevel-gears atp, which drives a second pair atq, one of which is fast on a spindle which passes through the vertical feed screw, and is secured thereto by the set screwe. The object of this arrangement is that if the self-acting vertical feed should be in action and the tool or swing frames′should meet any undue obstruction, the set screwewill slip and the feed would stop, thus preventing any breakage to the gears atporq. The feed screw is threaded into the top ofs′. Ateis the pin on which the tool box pivots to swing it at an angle.
Fig. 1597Fig. 1597.
Fig. 1597.
Fig. 1598Fig. 1598.
Fig. 1598.
The mechanism for actuating the cross-feed screw and the feed rod is shown in the top view,Fig. 1597, and the side view,Fig. 1598, in whichais a rod operated vertically and actuated from the stop (corresponding to stoprinFig. 1558) that actuates the belt shifting gear. Uponais the sleeveb, which actuates rodc, which operates the framed. This frame is pivoted upon a stud which is secured to the cross barc, and is secured by the nut ate. Framedcarries pawlsfandg, the former of which engages gear-wheelh, which drives the pinionn,Fig. 1598, that is fast on the feed rod, while the latter drives the geark, which in turn drives pinionp, which is fast upon the feed screw inFig. 1588.
Fig. 1599Fig. 1599.
Fig. 1599.
The feeds are put into or thrown out of action as follows:—On the same shaft or pin as the pawlsgandf, is secured a tonguet,Fig. 1599, whose end is wedge shaped and has a correspondingly shaped seat in a platev, whose cylindrical stem passes into a recess provided ind, and is surrounded by a spiral spring which acts to forcevoutwards from the recess.
In the position shown in the figure the end oftis seated in the groove inv, and the pressure of the spring acts to holdtstill and keep the pawlgfrom engaging with the teeth of gear-wheelh. But suppose the handlew(which is fast on the pawlg) is pulled upwards, andtwill move downwards, disengaging from the groove inv, and the upper end of pawlgwill engage with the teeth ofh, actuating in the direction of the arrow during the upward motion of roda, and thus actuating pinionnand putting the vertical feed in motion in one direction. When the rodamakes its downward stroke the pawlgwill slip over the teeth ofh, because there is nothing but the spiral spring to prevent the end of the pawl from slipping over these teeth. To place the vertical feed in action in the other direction, handlewis pressed downwards, causing the bottom endxof the pawl to engage with the teeth ofh.
Planer Beds and Tables.—The general forms of the beds of small planers are such as inFigs. 1557and1558, and those of the larger sizes such as shown inFig. 1563.
It is of the first importance that theV-guideways in these beds should be straight and true, and that the corresponding guides on the planer table should fit accurately to those in the bed; for which purpose it is necessary, if the greatest attainable accuracy is to be had, that the guideways in the bed first be made correct, and those on the table then fitted, using the bed to test them by.
The angle of these guides and guideways ranges from about 60° in the smallest sizes to about 110° in the largest sizes of planers. Whatever the angle may be, however, it is essential that all the angles be exactly equal, in order that the fit of the table may not be destroyed by the wear.
In addition to this, however, it is important that each side of the guides stand at an equal height, or otherwise the table will not fit, notwithstanding that all the angles may be equal.
Fig. 1600Fig. 1600.
Fig. 1600.
Fig. 1601Fig. 1601.
Fig. 1601.
Suppose, for example, that inFig. 1600all the sides are at an equal angle, but that sideewas planed down to the dotted linee, then all the weight of the table would fall on sidea, and, moreover, the table would be liable to rock in the guideways, for whenever the combined weight of the table and the pressure of the cut was greatest on the right-hand of the middlexof the table width and the feed was carried from right to left, then the table would move over, as shown exaggerated inFig. 1601, because the weight would press guidegdown into its guideways, and guidehwould then rise up slightly and not fit on one side at all, while on the other side it would bear heaviest at pointp. Great care is therefore necessary in planing and fitting these guides and ways, the processes for which are explained under the respective headings of “Examples in Planer Work,” and “Erecting Planers.”
In some designs the bed and table are provided with but oneV-guideway, the other side of the table being supported on a flat side, and in yet another form the table is supported on two flat guideways.
Referring to the former the bearing surface of theVand of theflat guide must be so proportioned to that of theVthat the wear will let the table down equally, or otherwise it would become out of parallel with the cross slide, and would plane the work of unequal thickness across its width.
Fig. 1602Fig. 1602.
Fig. 1602.
Referring to the second, which is illustrated inFig. 1602, it possesses several disadvantages.
Fig. 1603Fig. 1603.
Fig. 1603.
Thus, if there be four gibs as ata,b, ande,f, set up by their respective set-screws, the very means provided to take up the wear affords a means of setting the bed out of line, so that the slots in the table (and, therefore, the chucks fitting to these slots) will not be in the line of motion of the table, and the work depending upon these chucks will not be true. This may be avoided by taking up the wear on two edges only, as inFig. 1603ata,b, but in this case the bearing ateandfwould eventually cease by reason of the wear.
Suppose, for example, that the pressure of the tool cut tends to throw the table in the direction of arrowj, and the surfaces ataandfresist the thrust and both will wear. But when the strain on the table is in the direction of arrowk, the surfacesb,e, will both wear; hence while the width apart of the table slides becomes greater, the width apart of the bed slideways wears less, and the fit cannot be maintained on the inner edges of the guideways. It is furthermore to be noted that with flat guideways the table will move sideways very easily, since there is nothing but the friction of the slides to prevent it, but in the case ofV-guides the table must lift before it can move sideways; hence, it lies very firmly in its seat, its weight resisting any side motion.
It is found in practice that the wear of the guides and guideways in planer tables and beds is greatest at the ends, and the reason of this is asfollows:—
Fig. 1604Fig. 1604.
Fig. 1604.
InFig. 1604is a top view of a planer table, the cutting tool being assumed to be att, and as the driving gear is atgforcing the table in the direction of the arrowa, and the resistance is att, the tendency is to throw the table around in the direction of arrowsbandc. When the tool is on the other side of the middle of the table width as atf, the tendency is to throw the table in the opposite direction as denoted by the arrowsdande, which obviously causes the most wear to be at the ends of the slides.
As the feed motions are placed on the right-hand side of the machines the operator stands on that side of the machine atx, and starts the cut from that side of the table; hence unless the work is placed in the middle of the table width, the wear will be most in the direction of arrowsbandc.
The methods of fitting the guideways and guides of planer beds and tables is given in the examples of erecting.
Fig. 1605Fig. 1605.
Fig. 1605.
A very good method of testing them, however, is as follows:—Suppose that we have inFig. 1605a plate that has been planed on both edgesg,h, and that in consequence of a want of truth in the planer guideways edgegis rounding and edgehhollow, the plate being supposed to lie upon the planer table in the position in which it was planed.
Fig. 1606Fig. 1606.
Fig. 1606.
Now, suppose that it be turned over on the planer, as inFig. 1606, the rounding edge, instead of standing on the right-hand side of the planer table, will stand on the left-hand side, so that if that edge were planed again in its new position it would be made hollow instead of rounding in its length. It is obvious, therefore, that if a planed edge shows true when turned over on the planer table, theVs of the planer are true, inasmuch as the table moves in a straight line in one direction, which is that affecting the truth of all surfaces of the work that are not parallel to the cross feed of the tool, or, what is the same thing, parallel to the surface of the planer table.
Planing Machine Tables.—In order that the guides on the table of a planer may not unduly wear, it is essential that they be kept well lubricated, which is a difficult matter when the table takes short strokes and has work upon it that takes a long time to perform, in which case it is necessary to stop the planing operations and run the work back so as to expose the guideways in the bed, so that they may be cleaned and oiled.
It will often occur that the work will not pass beneath the cross slide, and in that case it should be raised out of the ways to enableproper oiling, because insufficient lubrication frequently causes the guides and guideways to tear one another, or cut as it is commonly termed.
The means commonly employed for oiling planerVs or guideways are as follows:—At the top of the guideways small grooves,g g,Fig. 1609, are provided, and at the bottom a groovex. In the guides on the table there are provided pockets or slots in which are pivoted pendulums of the form shown inFig. 1607ata. Each pendulum passes down to the bottom of groovexin which the oil lies, and is provided on each side with recessese, which are also seen in the edge view on the right of the figure.
Fig. 1607Fig. 1607.
Fig. 1607.
Fig. 1608Fig. 1608.
Fig. 1608.
The pendulums are provided with a long slot to enable them when the table motion reverses to swing over and drag in the opposite direction (as shown inFig. 1607); as they drag on the bottom of groovexof the bed they lift the oil it contains, which passes up the sides of the pendulum as denoted by the arrow, and into grooves provided on the surface of the table guide, as athinFig. 1608, in whichv′is the table guide,vthe guideway in the bed,goil grooves, (see sectional view,Fig. 1613),xthe oil groove at the bottom of the bedv, andh hthe oil grooves which receive the oil the pendulum lifts.
The oil grooveshon the table guide run into the groovesgin theV-guideway in the bed, hence groovesg gbecome filled with oil. But after the end of the table has passed and left the bedvexposed, the oil flows out of groovesgdown the sides of the guideway, and constant lubrication is thus afforded at all times when the stroke of the table is sufficient to enable the pendulums to force the oil sufficiently far along oil wayh. When the table reverses the pendulum will swing over and lift the oil up into grooves or oil waysh′.
Fig. 1609Fig. 1609.
Fig. 1609.
Fig. 1610Fig. 1610.
Fig. 1610.
Another and excellent method of oiling, also invented by Mr. Hugh Thomas, of New York, is shown inFigs. 1609and1610, in whichprepresents an oiling roll or wheel,V-shaped, to correspond to the shape of theVs. This roll is laced with cotton wick or braid, as shown by the dark zigzag lines, and is carried in a framef, capable of sliding vertically in a boxc, which is set in a pocket in the bedv, and contains oil. By means of a screws, the rollpis set to touch the face of the tableV, and the friction between the roll and theV, as the table traverses, rotates the roll, which carries up the oil and lubricates the tableVover its whole surface. The dust, &c., that may get into the oil settles in the bottom of the boxc, which can occasionally be cleaned out. In this case the oil is not only presented to the oil grooves (h,Fig. 1608), but spread out upon theVs; but it is nevertheless advisable to have the grooveshso as to permit of an accumulation of oil that will aid in the distribution along theVs of the bed.
This method of oiling has been adopted in some large and heavy planers built by R. Hoe & Co., and has been found to operate admirably, keeping the guides and guideways clean, bright, and well lubricated.
Fig. 1611Fig. 1611.
Fig. 1611.
Mr. Thomas has also patented a system of forced oil circulation for large planers. In this system a pumpp,Fig. 1611, draws the oil from the cellarsc(which are usually provided on the ends of planer beds) and delivers it through pipes passing up to the sides of theVs, thus affording a constant flow of oil. A reservoir at the foot of the pump enables the dirt, &c., in the oil to settle before it enters the pump, which can be operated from any desirable part of the planer mechanism. The pendulums are also used in connection with the forced circulation.
As the work is fastened to the upper face of a planing machine table either directly or through the intervention of chucking devices, the table must be pierced with holes and grooves to receive bolts or other appliances by means of which the work or chuck, as the case may be, may be secured.
For receiving the heads of bolts,T-shaped grooves running the full length of the table are provided, and in addition there are sometimes provided shortT-grooves, to be shown presently.
For receiving stops and other similar chucking devices, the tables are provided with either round or square holes.
Fig. 1612Fig. 1612.
Fig. 1612.
InFig. 1612is shown a section of a table provided withT-grooves and rows of round holes,a,b,c,d,e, which pass entirely through the table, and hence must not be placed so that they will let dirt fall through to theV-guides or the rack. Tables with this arrangementof holes and grooves are usually used upon small planers in the United States, and sometimes to large ones also.
It is obvious that the dirt, fine cuttings, &c., will pass through the holes and may find its way to theV-guideways. Especially will this be the case when water is used upon the tool to take smooth cuts upon wrought iron and steel. To obviate this the construction shown inFig. 1613is employed.
Fig. 1613Fig. 1613.
Fig. 1613.
Fig. 1613represents a section of one guideway of a table and bed. On each side of the tableVthere is cut a groove leaving projecting ribsb,c, and whatever water, oil, or dirt may pass through the holes (Fig. 1612), will fall off these pointsb,c,Fig. 1613, and thus escape the guideways, while falling dust will be excluded by the wingsb,c, from theVs.
Fig. 1614Fig. 1614.
Fig. 1614.
The capacity of a planer table may be increased by fitting thereto two supplementary short tables, as shown inFig. 1614, several applications of its use being given with reference toexamples in planer work. These supplementary tables are secured to the main table by set-screws ata, and have been found of great value for a large variety of work, especially upon planing machines in which the table width is considerably less than the width between the uprights or stanchions.
Fig. 1615Fig. 1615.
Fig. 1615.
Fig. 1615represents the arrangement of square holes andT-grooves employed upon large planers. The square holes are cast in the table, and are slightly tapered to receive taper plugs or stops against which the work may abut, or which may be used to wedge against, as will be hereafter described, one of these stops being shown atsin the figure.
Fig. 1616Fig. 1616.
Fig. 1616.
TheT-shaped slotsf,g,h, are to receive the heads of bolts as shown inFig. 1616. The bolt head is rounded at cornersa,b, and the square under the head has the corresponding diagonal corners ascalso rounded, so that the width of the head being slightly less than that of the slot it may be passed down in the slot and then given a quarter revolution in the direction of the arrow, causing the wings of the head to pass under the recess of theT-groove, as shown inFig. 1617, which is a sectional end view of the groove with the bolt in place. The square corners ateand atfprevent the bolt from turning round more than the quarter revolution when screwing up the bolt nut, and when the nut is loosened a turn the bolt can be rotated a quarter revolution and lifted out of the groove.
Fig. 1617Fig. 1617.
Fig. 1617.
Now it is obvious that these slots serve the same purpose as the longitudinalT-grooves, since they receive the bolt heads, and it might therefore appear that they could be dispensed with, but it is a great convenience to be able to adjust the position of the bolt across the table width, which cannot be done if longitudinal grooves only are employed. Indeed, it might easily occur that the longitudinalgrooves be covered by the work when the short transverse ones would serve to advantage, and in the wide range of work that large planers generally perform, it is desirable to give every means for disposing the bolts about the table to suit the size and shape of the work.
It is obvious that the form of bolt head shown inFig. 1616is equally applicable to the longitudinal grooves as to the cross slots, enabling the bolt to be inserted, notwithstanding that the work may cover the ends of the longitudinal slots.
The round holesa,b,c, &c., inFig. 1612, are preferable to the square ones, inasmuch as they weaken the table less and are equally effective. Being drilled and reamed parallel the plugs that fit them may be passed through them to any desirable distance, whereas the square plugs being taper must be set down home in their holes, necessitating the use of plugs of varying length, so that when in their places they may stand at varying heights from the table, and thus suit different heights of work. Whatever kind of holes are used it is obvious that they must be arranged in line both lengthways of the table and across it, so that they will not come in the way of the ribsr, which are placed beneath it to strengthen it.
The longitudinal grooves are planed out to make them straight and true with theV-guides and guideways, so that chucking appliances fitting into the grooves may be known to be set true upon the table.
Fig. 1618Fig. 1618.
Fig. 1618.
InFig. 1618, for example, is shown an angle pieceahaving a projection fitting into a longitudinal groove, the screws whose heads are visible passing throughainto nuts that are in the widened part of the groove, so that operating the screws securesato the table. The vertical face ofabeing planed true, a piece of work, as a shafts, may be known to be set in line with the table when it is clamped againstaby clamps as atp, or by other holding devices. Angle pieces such asaare made of varying lengths and heights to suit different forms and sizes of work.
Fig. 1619Fig. 1619.
Fig. 1619.
In some planing machine tables aV-groove is cut along the centre for the purpose of holding spindles to have featherways or splines cut in them, the method of chucking being shown inFig. 1619. This, however, is not a good plan, as the bolts and plates are apt to bend the shaft out of straight, so that the groove cut in the work will not be straight when the spindle is removed from the clamp pressure. The proper method of chucking such work will, however, be given in connection withexamples on planer work.
For the round holes in planer tables several kinds of plugs or stops are employed, the simplest of them being a plain cylindrical plug or stop.
Fig. 1620Fig. 1620.
Fig. 1620.
Fig. 1620represents a stop provided with a screwb. The stemafits into the round holes, and the screw is operated to press against the work. By placing the screw at an angle, as shown, its pressure tends to force the work down upon the planer table.
Fig. 1621Fig. 1621.
Fig. 1621.
A similar stop, termed a bunter screw,s,Fig. 1621, may be used in the longitudinal slots, the shape of its hook enabling it to be readily inserted and removed from the slot. These screws may be applied direct to the work when the circumstances will permit, or a wedgewmay be interposed between the screw and the work, as shown.
Fig. 1622Fig. 1622.
Fig. 1622.
Fig. 1622represents a form of planer chuck used on the smaller sizes of planers, and commonly called planer centres.ais the base or frame bolted to the planer table at the lugsl; atbis a fixed head carrying what may be termed the live centred, andcis a head similar to the tailstock of a lathe carrying a dead centre;fis an index plate having worm-teeth on its edge and being operated by the wormg. Atsis a spring carrying at its end the pin for the index holes. To bring this pin opposite to the requisite circle of holes, the bolt holdingstoais eased back andsmoved as required. On the live centredis a clamp for securing the work or mandrel holding dog. Headcis split as shown, and is held to the surface ofaby the bolth, which is tapped into the metal on one side of the split.
It is obvious that polygons may be planed by placing the work between the centres and rotating it by means ofgafter each successive side of the polygon has been planed or shaped, the numberof sides being determined by the amount of rotation of the index plate.
Fig. 1623Fig. 1623.
Fig. 1623.
Fig. 1623shows a useful chuck for holding cylindrical work, such as rolls. The base is split ate, so that by means of the bolt and nutdtheV-block a may be gripped firmly;bandcare screws for adjusting the height of theV-blocka. Atfis the bolt for clamping the chuck to the planer table, andgis a cap to clamp the workwin the blocka. It will be seen that this chuck can be set for taper as well as parallel work.
Fig. 1624Fig. 1624.
Fig. 1624.
Fig. 1624represents a chucking device useful for supporting or packing up work, or for adjusting it in position ready to fasten it to the work table, it being obvious that its hollow seat ataenables it to set steadily upon the table, and that its screw affords a simple means of adjusting its height. It may also be used between the jaws of a connecting rod strap or other similar piece of work to support it, as inFig. 1625, and prevent the jaws from springing together under the pressure of the tool cut.
Fig. 1625Fig. 1625.
Fig. 1625.
Fig. 1626Fig. 1626.
Fig. 1626.
Another and very useful device for this purpose is shown inFig. 1626, consisting of a pair of inverted wedges, of which one is dovetailed into the other and having a screw to operate them endwise, the purpose being to hold the two jaws the proper distance apart and prevent their closure under pressure of the planer vice jaws. It is obvious that the device inFig. 1625is most useful for work that has not been faced between the jaws, because the device inFig. 1626would, upon rough work that is not true, be apt to spring the work true with the inside faces, which may not be true with the outside ones, and when the wedges were removed the jaws would spring back again, and the work performed while the inverted wedges were in place would no longer be true when they were removed.
Fig. 1627Fig. 1627.
Fig. 1627.
Fig. 1627represents a centre chuck to enable the cutting of spirals. The principle of the design is to rotate the work as it traverses, and this is accomplished asfollows:—
Upon the bed of the machine alongside of the table is bolted the racka a, into which gears the pinionb, which is fixed to the same shaft as the bevel-gearc, which meshes with the bevel-wheeld. Upon the same shaft asdis the face platee, and in the spindle upon whichdandeare fixed is a centre, so that the plateeanswers to the face plate of a lathe.fis a bearing for the shaft carryingbandc, andgis a bearing carrying the spindle to whicheanddare fixed.his a standard carrying the screw and centre, shown ati, and hence answers to the tailstock of a lathe.krepresents a frame or plate carrying the bearingsfandg, and the standardh.lrepresents the table of the planing machine to whichkis bolted. The reciprocating motion of the tablelcauses the pinionbto revolve upon the racka a. The pinionbrevolvesc, which imparts its motion tod, and the workwbeing placed between the centres as shown, is revolved in unison withe, revolving in one direction when the tablekis going one way, and in the other when the motion of the table is reversed; hence a tool in the tool post will cut a spiral groove in the work.
To enable the device to cut grooves of different spirals or twist, all that is necessary is to provide different sizes of wheels to take the places ofcandd, so that the revolutions ofe, and hence of the workw, may be increased or diminished with relation to the revolutions ofb; or, what is the same thing, to a given amount of table movement, or a stud may be put in so as to enable the employment of change gears.
Fig. 1628Fig. 1628.
Fig. 1628.
Figs. 1628and1629represent a universal planer chuck, designed and patented by John H. Greenwood, of Columbus, Ohio, for planing concave or convex surfaces, as well as ordinary plane ones, with the cross feed of the common planer.
The baselof the chuck is bolted to the planer work table in the ordinary manner.
The work-holding frame or vice is supported, for circular surfaces, by being pivoted to the base ato,o, and by the gibbed headd, which has journal bearing ate. The work is held between the stationary jawborb′(at option) and the movable jawcwhich may face eitherborb′(by turningcround). Suppose then, that while the chuck is passing the cutting tool, endiof the work-holding frame is raised, lifting that end of the work above the horizontal level (the work-holding frame swinging at the other end on the pivotso,o), then the tool will obviously cut a convex surface. Or if endiof the work-holding frame be lowered while the cut is proceeding, the tool will cut a concave surface.