US2018435A - Profiling machine - Google Patents

Description

1935- F. J. BlCKEL PROFILING MACHINb Filed May 12, 1933 4 Sheets-Sheet 2 .llrilillllv .ltlaldl 1 1!!! filial ATTORNEYJ,

F. J BICKEL PROFILING momma Fi led May 12, 1935 Oct. 22, 1935.

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! I/IIIIIIII IIIIIIIIIIIIIIIIIIIIIIIII Patented Oct. 22, 1935 PATENT OFFICE PROFILING MACHINE Frederic J. Bickel, Cleveland, Ohio, assignor to The Osborn Manufacturingcompany, Cleveland, Ohio, a corporation of Ohio Application May 12, 1933, Serial No. 670,729 21 Claims. (01. 90-13.?)

This invention relates to amachine and method for cutting in an irregular path and is particularly directed to the problem of cutting cams for automatic machinery quickly, cheaply and accurately. I

In making cams for automatic machinery where a number of different cams have to be made in order to satisfy special conditions of machine operation the cost of preparing the cams is sometimes almost prohibitive. For example such a situation occurs when an automatic machine has to be put through a special cycle for a comparatively small quantity of production and the cam used for the purpose may never be needed again. By my improved machine and method -.I am enabled, first to lay out the cam profile on the material which is toform the final cam, next to transfer this to a master, and finally use the same machine in changed arrangement to cut the actual cam very accurately to the original layout line. The master is not strictly a templet, for, although it corresponds to the cam outline, it is preferably on a different scaleand may not be of the same shape, although it must be of a shape from which the cam can be accurately reproduced. The machine and method can be used to produce various types of cams. such as disk or drum, peripheral or grooved,- and modified forms, all as will be apparent from the following specification. The operation automatic and relatively speedy and the degree of accuracy obtainable is higher than by any other method of which I amaware.

In its present preferred embodiment this invention is best exemplified in certain attachments for and methods of operating a milling machine of the vertical spindle type.

To the accomplishment of the foregoing and related ends, said .invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and thefollowing description setting forth in detail certain means and one mode of carrying out the invention, such disclosed means and mode illustrating, however, but one of va-' rious ways in which the principle of the invention may be used.

Inlthe accompanidng drawings Fig. 1 is a front elevation of a milling machine with my invention applied thereto; Fig. 2 is a partial plan view taken from Fig. 1 approximately on the line 2-2; Fig. 3 is a detailed plan of one form of the tracer unit of my invention; Fig. 4 is a sectional view of the same on the line 4-4 of Fig. 3; Fig. 5 is an enlarged detail from Fig. 1, partly in section, showing the means for traversing the zontal turning axes.

carriage on the rack; Fig. 6 is a top plan view of the mechanism of Fig. 5; Fig. 7 is a view on a vertical plane, partly in section and partly in elevation, approximately along the line 1-1 of Fig. 6; Fig. 8 is a detail partly in section and partly in elevation on the line 8-8 Fig. 7 Fig. 9 5 is a partial vertical section on the line 9-9 Fig.

5; Fig. 10 is a front elevation of a modified form of tracer unit; Fig. 11 is a. central vertical sec-' tion through Fig. 10 on the line I l-II; Fig. 12

is a horizontal section through Fig. 11 on the 10 line l2--|2, looking upwards; Fig. 13 is a perspective view of' an attachment; Fig. 14 is a horizontal section through the attachment of Fig. 13, taken on the line |4l4 of Fig. 10; Fig. 15 is a vertical section on'the line l5-l5 of Fig. l5 14; Fig. 16 is an enlarged portion of a view which generally corresponds to Fig. 2; Figs. 17 to 22 inelusive are diagrammatic illustrations of various set-ups of the machine; Figs. 23 and 24 illustrate further modifications.

General arrangement The general arrangement of the apparatus is shown in Fig. 1 wherein it is shown as applied to a vertical spindle milling machine, the ma- 25 chine being equipped with both vertical and hori- The machine comprises a base I, standard 2, horizontal arm 3 vertically adjustable on the standard, a horizontal turntable 4 adapted to carry fiat disks and a horizontal mandrel 5 adapted to receive cylindrical work. A motor 6 drives the table 4 or mandrel 5 or both through suitable reduction gears contained. in a supporting base 1. As herein illustrated, the machine is provided with a control 18- ver 8 for setting into operation either the table 4 or the mandrel 5 or both. A hand actuated wheel 9 is provided for use in turning the mechanism by hand, as in setting up the work, etc.

A carriage generally indicated by the reference 40 character i5 is movable along the arm 3. This carriage l5 carries a milling unit IS, a control unit l1, shown in detail on Sheet 2, and atracer unit l8, one form of which is shown in'Figs. 3 and 4, and another form of which-is shown on Sheet 3. A center brace or steadying post i 9 connects the horizontal table 4 with the arm 3 to give greater stiffness and accuracy to the mechanism.

The millingunit itself may be of standard construction and is here shown as a vertical spindle 25 carrying at its lower end a cutter bit 26 and driven by a pulley 21 taking power from a belt 28 driven by a suitable train of mechanism not shown, power preferably being applied tothis wheel 55 driven by a that the lower bar set to follow the layout line 5|.

' meshes with and 3|, Fig. 1, which turns a pinion 32 travelling on.

a vertical rack 33, Figs. 5 and 9. It will be noted 35 of the horizontal arm 3 is fitted with a toothed rack 36 on its upper surface. The carriage I5 is moved and set along the horizontal arm 3 by the control unit H which drives a pinion 31, Fig. 9, along the rack 36 as more fully explained in the detailed description of the, control unit, below. The lower part of the carriage I51carries a horizontal bar 40 ina suitable clamping arrangement such as that indicated in a general way by the sleeve 4|. This bar may also be conveniently guided through a sleeve 42 on the center brme I9. The tracer unit I8 is clamped to the bar 40 in any suitable manner, as by the split sleeve 43 which can be clamped bythe bolts 44, Fig. 4. Thus, movement of the carriage I5 along the arm 3 moves the tracer unit I8 as well as the milling unit IS, without changingthe mutual relationship between these two.

The operation, ,in general terms, is that a cam plate such as is placed on the machine where it is to be used, and a cam layout, such as 5|, Fig. 2, is outlined thereon by any suitable means. The cam blank- 50 is superposed on a templet or master blank 52 on the table 4 and both are secured to the table 4 to rotate therewith. A follower 53, which is part of the tracer unit, is

v As this follower moves to accommodate itself to the formations in the layout line it actuates suitable mechanism to cause the control unit H to move the carriage I5 back and forth along the horizontal arm 3, thus causing the cutter 26 to follow a course 54, concentric with the line 5|. In the present illustrative embodiment, as shown in Fig. 2, the direction of the table 4, seen from above, is counter-clockwise, as indicated by the arrow T. With the set-up shown in Fig. 1, thecutter path 54 is a groove; with a deeper setting of the cutter 26 that portion of the master which is outside the cutter path 54 could be cut off After the master has I8 is moved to another so that the follower 53 will run in the master path 54 and the cutter 25 will cut the cam 50 along the original line 5|. Fig. 17 shows this second stage, cutting a groove 55 in the cam plate 50, thus making a face cam. A disk cam would be made by a deeper setting of the cutter 26, removing the outer part of the plate 50. Various modifications of the steps just described are possible, and some of these will be explained under the heading Operation.

entirely. been cut the tracer unit position on the rod 40,

Control unit The control unit, generally indicated at I! in Fig. 1, is illustrated in detail in Figs. 5 to 9 in clusive. It comprises a frame generally designated as which is rigidly connected to, and may form part of, the structure of the carriage I5. In detail this frame 60 comprises an upright tubular member 6| and a gear case 63. A horizontal shaft 64 journalled at one end in the back of the gear case 63 and at the other end in the saddle 62 has fixed upon its one end'a worm worm 65 uponthe lower end of a vertical shaft 61, and at its other end the pinion 31, previously mentioned, which moves along the rack 35. The

top of the shaft 61 is squared to receive a tool,

movable by hand'in exceptional instances, such as setting the machine, etc. Since .a high degree of accuracy is one of the features of the present invention, some means for preventing backlash between the pinion and rack is desirable. A convenient arrangement is shown in Fig. 1 where a weight 58 is suspended by a cable 68. This cable, passing over a series of pulleys, the last of which, 10, on the far end of the arm 3, reverses the direction of pull, is attached to the carriage I5 so as to create a constant outward pull on the carriage, thus keeping the teeth of the pinion 31 tight in one direction against those of the rack38.

The shaft 61, Fig. 5, carried. by suitable bearings in the upright BI, is revolved in either direction in response to the movements-of the follower 53, Fig. 1.

Although this responsive movement may be ac complished by the use of any suitable mechanism which will give a sufficient degree of accuracy, I prefer to employ a pair of oppositely directed pawls I3 and 14 carried upon a vibrating arm I5 and adapted to engage corresponding ratchet wheels I6 and 11 respectively, these 25 wheels being fast to the upper end of the shaft 61. This arm 15 is pivoted as indicated at 18, Fig. 7, concentrically upon the upper endof the shaft 61, and in the present instance is actuated or vibrated by a link 19 moved by an eccentric on the upper part of the shaft 25, though other suitable means may be employed. These details of connection are omitted from Fig. 1 to avoid'confusion. Rotation of the shaft 61 except by the pawls is prevented by a notched disk 8| on the bottom of the shaft, and a detent 82 engaging the notches. The preferred means of actuating the pawls is by electromagnets 83 and 84, each having its two poles brought together near one end as at 85 and 86 in the case of the upper magnet. The tail 8'! of the upper pawl 13 is attracted when this magnet is energized, thus bringing the point of the pawl against one of the ratchet teeth of the wheel I5. A button actuated by a spring 88 and 46 bearing against a piece of non-magnetic material 89 between the pole pieces 85 and 86 throws the pawl out of engagement when the circuit is broken. The magnet 84 and pawl'14 are correspondingly arranged, but of course in reversed 50 direction, and the teeth of the lower wheel 11 point oppositely to those of the upper wheel I5. The wiring of the magnets is indicated diagrammatically in Fig. 8, the wires being similarly numbered at the tracer unit, Fig. 3. As will be 05 described hereafter, the magnets are operated by the tracer unit, which unit will now be described in detail.

Tracer unit The tracer unit is generally indicated by the reference character I8, Fig. 1. Such a unit is shown in its simplest form in Figs. 3 and 4. Another form, preferably for certain classes of work, is illustrated on Sheet 3, Figs. 10 to 15 inclusive. The form shown in Figs. 3 and 4 comprises a supporting arm I00, forked at its lower end as at |0| and adapted to be fastened by the clamp 43 at its upper end to the rod 48. Pivots such as I02 carried by the fork support one end 70 of a plate I03 of non-conducting material which will hereafter be termed the tracer plate. This plate, which may conveniently be covered by a protective housing I04, carries at its free end a pair of vertical bearings I05 between which a I feeler arm I06, forming part of. the electric control circuits, is pivoted. This arm includes a relatively very short forward extension I 01 carrying the needle 53or some equivalent follower member. In the remainder of the description the term follower is used in a somewhat general sense to refer either to this needle or to a member having similar functions. Various forms of followers are described below.

The movement of the rear end of the arm I06, which carries a double contact point I00, is limited by opposite horizontally disposed contacts I I and I I I, with'one of which the point I08 contacts as the arm I06 swings. A wire 90 from one side of any suitable source of power, such as a battery B, is connected with the arm I06 in any convenient manner. A wire 90A from the other side of B is common to both magnet circuits, as shown in Fig. 8. Condensers C are bridged across the contacts I08-I I0 and I 08-I II to reduce arcing. The wires 83 and 94 are respectively connected to the contact points H0 and III. comparing Fig. 3 with Fig. 8, since the corresponding wires of the magnet circuits bear the same numbers in each figure, it will be seen that movement of the follower toward the bottom of the page (to the left in Fig. 2) will energize the upper magnet 03 and thus move the cutter 26 to the left. The cutter carries with it the rod 40 and thus moves the tracer unit l8 to the left, causing the follower to resume its central position, which moves the arm I06, thus opening both control circuits and leaving both magnets inoperative.

- Since the tracer unit is made responsive to very close variations in the layout or templet path 54, on the order of .001 inch, suitable adjusting means are provided, of well-known character, not described in detail.

Figs. 10 to inclusive illustrate a modified follower, generally designated as I8. .As illustrated, this modified form is equipped with a roller I I6 instead of a needle point. It would also be within the purview of the invention to use a needle point on the form shown in Fig. 10 or to use a roller on the form shown in Figs. 3 and 4. Under some conditions a roller such as II6 has a tendency to climb and it may be advisable to employ a non-rotating member. There is some discussion below of the relative diameters of the roller H6 and the cutting tool 26. Where pertinent it will be understood that if a finger is used instead of a'roller, the finger will be of such size as to causethe elements in tracing their various paths to conform as to center lines, etc.. all of which will be readily understood as the description proceeds. This matter will be further discussed under the heading Operation".

The modified follower comprises an anchor I threaded shaft I21 having thumb nuts I28 at each end. The body I26 houses and supports the tracer mechanism. This mechanism consists of two superposed levers I30 and I3I, also called respectively. the tracer pin .carrier arm and the contact point carrier arm. The lower lever I30 is of the first'order, having a fulcrum I34 between the short front arm I35 and the long rear arm. The upper lever I3I has its fulcrum HP at one end, slightly beyond the free end of the its upper end is fastened into a part of the body I26. The arm I35 of the lower lever carries a roller II6 upon the lower end of a tracer roller pin I36, with appropriate details, such as the set screw I31 for vertical adjustment, and a collar I38 adjustably secured upon the pin I36 and holding down a short coiled spring I39 which bears down upon the roller I I6, holding the roller axially against the enlarged lower end of the pin I36, as will be seen in Fig. 11. A vertical pin I40 secured in and depending from the contact point arm I3I near its fulcrum,.is engaged at its lower end between the two sides of a fork I4I within By an arrangement seen in Fig. 12 the lever system can be left free to respond to movements of the roller H6 in either direction or can be selectively urged toward one side or th other. This is accomplished by means of a tension spring I 32 and a tension spring lock I50. Thespring is a fiat leaf rigidly bracketed at I33 to the contact .point arm I3I and extending parallel to and below that arm in the direction away from the fulcrum I3I'.

' The lock consists of a rod disposed transversely across the tracer lever housing and capable of a limited axial movement. This rod has a knurled head or thumb piece. I5I at one end, is' reduced in diameter at the other end for a length not less than its allowable travel, and is also annularly grooved at I52 at its mid length. A radial pin I53 is fixed in the rod near the thumb piece I5I. The lock I50 is rotated and the radial pin I53 engages with suitable stops (not'shown) when the rod is rotated, to hold the rod in any one of three positions against axial movement. The position illustrated in Fig. 12 is neutral and leaves the lever system free to move in either direction according to the movements of the roller II 6. When the thumb piece I5I of the lock I50 is moved toward the tracer unit housing and the lock turned to engage the pin I53 against its stop (which may be the inner wall of the housing), the corresponding shoulder of the groove I52 is brought to bear against the free end of the spring I32 and the arm I 3| is thus given a constant tendency clockwise (as seen in Fig.

12) about its fulcrum. This in turn moves the roller H6 in the opposite direction and causes it to bear constantly against its guiding surface, such as the wire 5IA in Fig. 10. This wire 5IA, to be described in more detail below, serves the same purpose as the groove 5|. If the guiding surface were on the other side of the roller II6 the tension spring lock would be moved and set in the opposite sense.

'The electrical system is, in general similar to that of Figs. 3 and 4 and the same reference characters will be used to designate the various wires, since these,wires perform the same functions in the circuit and the connections to the magnets in Figs. 6, 7 and 8 are precisely the same. The

wiring-is somewhat more compact than that indicated in Figs. 3 and 4, all of the leads to and from the tracer unit housing being combined in a cable I54. The circuit includes a source of power such as the battery B, connected by the conductors 90 and 90A to the upper lever I3I and to the magnets, Fig. 8, respectively. Condensers C are bridged across the contact points I08A-- DA and I08A-I I IA. The double contact point I08A completes the circuit through the contact IIO A or IIIA, as the case may be. From the contact I IOA a wire 93 leads to the magnet 83 and from the contact IIIA a wire 94 leads to the magnet 84. (See Figs. 12- and 8.) The contact points are adjustable. by any suitable means, that shown being by having them mounted on the inner ends of screws I I03 and IIIB respectively (Fig. 10) these screws passing through the centers of the binding posts.

Besides the electrical control, a visual indicator is provided consisting of a needle I60 on the face of the tracer unit body. Thisneedle is pivoted at its bottom and is given a constant clockwise tendency (Fig. 10) by any convenient arrangement, such as the coiled spring I6 I. A pin I62, fixed to and projecting down from the needle,

is thus kept in constant contact with the pin I43.

' its application is indicated by dotted lines in Fig. 10.

This extension comprises an arm I1I with a flat end which can bear accurately against either side of the body I26 and with a bracket I12 on its" other end, which will be designated as the free end.

This bracket carries a short arm IA pivoted upon the pin I34A, these parts being analogous to the parts I35 and I34. A set screw I31A in the arm I35A holds the pin I36, which, with its roller H6 and various other elements, is removed from the lever arm I35 and inserted in 135A when the extension is used. Ears I13 and I14 on each end and each side of the arm I1I are aperturedlongitudinally for two purposes. As will be apparent from inspection of Fig. 14, the apertures on one side serve as guide bearings for a push rod I80 which transmitsthrust from the lever arm I35A to the'lever arm I35. The aperture in the other ear I13 fits over a dowel pin I8I in the side of 'the tracer unit body.

This dowel pin and the adjoining flat surfaces of the plate I28 on the bottom of the body and at the end of the arm I1I position the arm I1I very accurately. A cap screw such as I82 (Fig. 15) holds the arm I1I'.in position. There is also an upper dowel pin I83 which fits in an appropriate recess higher on the end of the extension arm. The dowel pins just mentioned are duplicated on the other side of the tracer uhit body. Thus, by reversing the end of the extension arm and putting the rod I80 through the apertures on the opposite side, the extension may point in a direction opposite to that shown. I

-It is within the scope of the invention to use other tracer units. For example, a photoelectric cell following a line of contrasting light value might be used in place of either of the tracer units which have been described above.

Operation As already mentioned, the usual mode of operation is that during the first revolution of the table 4 the follower 53 or II6 follows the layout line on the cam and the cutter 26 forms apath on the master; during the second revolution the follower follows the master path and the cutter cuts to the layoutline on the cam. Thus the first cam is formed in two complete revolutions of the table, and subsequent cams are formed in one revolution. Theoretically, if the camlayout were a circle concentric with the table center, the tracer unit would never move during the entire revolution, the magnets 13 and 14 would never be energized, and the carriage I5 would never move along the arm 3. In practice some corrective movement would be given even in concentric circular work, since no machine of this sort can be expected to run with theoretical perfection. Of course the tracer and control units are in continual action whenever working on non-i circular or non-concentric parts of the cam. The detailed operation of the control unit 1I1'has already been described and will not be further mentioned except to point out that when the upper magnet 83 is energized and its pawl is engaged with the wheel 16, the arcuate swing of the arm 15 turns the shaft 61 clockwise (Fig. 6) thus tm'ning the worm wheel 65, horizontal shaft 64 and pinion 31 counter-clockwise and so moving the carriage I 5, which, it will be remembered, carries a the rod 40 with cutter and tracer unit, to the rapid while the turning of the table .4 (and of the shaft 5 when working on drums) is relatively very slow. For this reason the fact that the shafts 61 and 64 take an intermittent instead of a steady movement is negligible in efliect, introducing an error which is within the limits of tolerance in the final product. It would be within the scope of the invention to use suitable mechanism to apply the corrective movement continuously, but the arrangement shown in Fig. 2 has given satisfactory results, and so far has been superior in accuracy to any continuous movement means. It

will be understood that by continuous movement I mean a movement that would be continuous only so long as the follower was away from its central position.

. A number of different arrangements of cam, master, cutter unit and tracer unit are possible. That illustrated inFigs. l and 2 has. already been described under the heading General arrangement" and will be taken as standard for purposes of. comparison although in reality no particular setup is more standard than any other. The one most appropriate to the workv in hand will be used in each instance.

Several variations are illustrated in diagram--. matic style on Sheet 4, Figs. 16 to 22 inclusive, and will bedescribed briefly. So far as possible the same reference characters as in Figs. 1 and 2 75.

will be used, distinguished by letters or primes.

In using a roller follower such as "6 it is necessary for highly accurate work to have the roller ofthe same diameter as the width of the finished cam groove. The diameter of the cutter for the master is immaterial but when the tracer unit is following the master, the follower I I6 must have the same diameter as the cutter with which the master was cut. This is explained in connection withFig'. 16. As Fig. 16 shows, the layout on the cam plate 59A may be a wire 5IA instead of a groove. This wire will define what will ultimately become one edge of the cam plate,

for a disk cam, or one edge of the cam groove for a face cam. A convenient way of locating the wire is to lay out the cam path by a series of center punch marks such as I offset from the edge line a distance equal to the cutter radius,

place on the punch marks successively a button such as I9I of the cutter diameter and having a center point fitting the punch marks, then bend the wire 5IA in a smooth curve tangent to the button as it is moved from one position to-the next and tack-solder the wire in position. The wire is shown as inside, that is, toward the center of the plate 50A, but it might equally well be laid outside. Then as the cam plate 50A is rotated, the center of the roller I I6 will follow the path I92R, and the center of the cutter bit 26 will follow the corresponding path I92C. Since the bit and roller for the cam are of equal diameter, and the bit and roller for the master are of equal diameter, the sides of the master groove 54 (or its edge 54E if the cut is entirely through the master) will correspond to the position of the wire 5lA, with the result that when the cuttersand rollers are interchanged for position the groove edge (or the face, as the case may be) of the cam as finally cut will be exactly as was originally defined by the wire. This condition will obtain throughout workable ranges of sharp and irregular curves.

By way of explanation, if I93 be taken as the center of the cutter position corresponding to roller center position I99, and I93 be the position corresponding to another roller center position- I96, it will be seen that the distance,

I93'I99 equals I93- I90', because for any particular job the cutter unit and tracer unit are always fixed on the bar 40. But if each of the lines I93I9Il and I93'I90 be projected to intersect 5IA at I94 and I94, respectively, the

distance I93 I94 will be less than I93'-I94'.-

Also, calling the intersections with the edge 54E I94 and I95 respectively, I94I95 is shorter than I94'I95 The only series of points constantly spaced, and therefore interchangeable, are paths I 92R and I92C, of the tracer center and cutter center.

In Fig. 17 the tracer unit is shown with its roller II6 running in a groove 54 in the master 52A while the cutter 26 is milling a face cam groove 55 in the cam plate 59A. The wire 5IA is shown here to indicate the relative positions. It might be removed either before or after the cam is completed. I I y Another arrangement is that of Fig. 18 wherein the cutter 26 and tracer I8.are on opposite sides of the center brace I9. Here only a single piece 50B is used for both master and cam. On the first revolution (not illustrated) the tracer follows the wire 5| B and the cutter 26 cuts the master groove 54B. On the second revolution, illustrated, the tracer follows the groove 54B and the cutter cuts the final cam groove 553. This of the center I9. 5

Figs. 19 and 20 illustrate diagrammatically a set-up for cutting a drum cam, using a fiat master. The direction of rotation is'indicated by the arrow. A pair of bevel gears I96 are shown to indicate diagrammatically that the drum 10 shaft 5 and table 4 rotate synchronously. In

Fig. 19 the drum 50D is shown with the layout line 5ID thereon with the tracer I8 following this line. The cutter 26 is forming the master 52 as in Figs. 1 and 2. In Fig. 20 the master 52 has 1g ;v

been formed and the follower I8 is following its edge while the cutter 26 cuts the final cam path 54D in the drum.

A further modification is shown in Figs. 21 and 22, wherein the master is also drum-shaped 20 and mounted co-axially with the cam drum 50D on the shaft 5. As with the flat forms, the relative sizes of master and cam drum may vary. In the present example the master is smaller in diameter. The principles of operation are the 25 same. As seen in Fig. 21 the layout line 5ID on the cam drum 59D is followed by the-tracer I8, which governs the movement of the cutter 26 forming the groove 54D on themaster 52D. Cutter and tracer are then reversed, as shown 30 in Fig. 22, and the final camgroove 55D is cut on the cam drum 50D.

A further modification is shown in Figs. 23 and 24. Here the cam layout line 5IE is marked on the cam blank in a contrasting. color and is 35 followedby a photoelectric cell I8E instead of by a needle or a roller. On the first revolution the cutter is replaced on the bar 46 by a marking mechanism 200 (for example, a recording pen), which marks a master path 54E on suitable lila- 40 terial, such as a sheet of cardboard.- For the second, cam forming, revolution the photoelectric cell I SE is positioned to follow the master line 54E and a cutter 26 as in Fig. 2 is used to cut the final cam path 55. This method is of 45 course susceptible of various modifications along the lines already suggested, such as combinations of fiat elements and drum elements, the use of grooves instead of colored lines, needles instead of the elements 290 and I8E, and so on. my

Under certain circumstances it may be advisable to use the machine for only a part of the complete process. For example, in instances where it is possible to lay out the cam on a. scale larger or smaller than actual size, the layout 55 line can be scribed, wired, or otherwise formed by hand on the master blank; the master and cam blank are then placed on the machine and the cam cut in one revolution, running thefollower on the layout line while the cutter cuts the 0 cam. In other situations it may be desirable'to produce the completed master alone as an article of manufacture. All such specialized adaptations of the invention to particular conditions are within the scope of the invention.

The invention, several examples of which have been described in detail, thus comprises methods 7 and means whereby a delicate guide, requiring very little power for its operagion, positions a cutter which must be strongly, eld and strongly 7 driven. In the most usual cycle of operations this guiding and cutting relationship will be used first to transfer the cam layout line to a permanently projected form on solid material, and next to use this projected form as a. guide for cutting back to or through the layoutline, in certain instances destroying the layout line by this final cut. For specialized conditions cer-- tain steps of the process may be changed in sequence, or omitted.

Although several possible arrangements have been shown it will be understood that all of these are intended more particularly to illustrate principles than to show all detailed possibilities. Many other variations of the principles will sug- 'gest themselves, being characterized by having the master and the cam rotatable in some definite relationship and the path-following unit and path-tracing unit movable on both master and cam in some definite relationship to master and cam and to one another.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the means and the steps herein disclosed, provided those stated by any of the following claims or their equivalent be employed.

I therefore particularlypoint out and distinctly claim as my invention. 1. In a profiling machine a. tracer unit, a follower supported thereby, adapted to follow a pattern, a movable support for said follower, stop means on said tracer limiting. the follower movement, a path-making element in predetermined spaced relation to said tracer unit, and means for causing said follower support and 'said path-making element to move under the guidance of the movements of the follower.

2. Ina profiling machine a tracer unit, a follower supported thereby, adapted to follow a pattern, a movable support for said follower, stop means on said tracer limiting the follower movement, a path-making element in constant spaced relation to said tracer unit, and means for causing said follower support and said pathmaking element to move in unison in conformity to the movements of the follower.

3. In a profiling machine a tracer unit, a follower supported thereby, adapted to follow a pattern, a movable support for said follower,

stop means on said tracer limiting the follower movement, a path-making element in constant longitudinal spaced relation to said tracer unit, and means for causing said follower support and said path-making element to move in unison in conformity to the movements of. the follower.

4. In a profiling machine, a rotatable work support, a work piece supported thereon, a pattern outline on said work piece, a follower adapted to follow said pattern outline on the work, a carrier for said follower whereon said follower is mounted for limited independent movement in response to variations of said pattern outline, a cutter at fixed radial distance from said follower carrier, a common support means for said follower carrier and for said cutter, and means for moving said common support means in conformity to the variations of said outline to restore said follower to predetermined position upon the follower carrier.

' 5. In a profiling machine in combination a revolving table, a cam pattern fixed to said table, a member to be cut revolving in synchronism with said table, a 'rod disposed above said table and above said member to be out, said rod being radially disposed to said table, a cutter fixed to said rod and a control mechanism element adapted to respond to variations of the pattern with respect to itself and to move said 6. In a profiling machine in combination, a

"revolving table, a'longitudinal rod thereabove, a cam pattern fixed to said table, a member to be cut fixed to said table, a cutter fixed to said rod and-a control mechanism element also fixed 5 to said rod and adapted to vary from a normal position in response to variations of the pattern and'by such variation to apply power to move said rod to restore the control mechanism element tonormal position and thereby move said 10 cutter according to the pattern.

7. Ina machine of the class described, a work rotating element, a tracer and a cutter, a mounting whereby said tracer and cutter are maintained in constant mutual relationship to the 15 progress of the workgmeans for moving said. tracer and cutter with respect to a path on the work.

8. In an apparatus of the class described, in sub-combination, a tracer unit extension com- 20 prising an arm adapted to be rigidly secured tov either side of the tracer unit, alever carriedby said extension, a follower carried by said lever, and an extension rod adapted to transmit motion from said leverto the lever mechanism of said tracer-25 unit.

9. In an apparatus of the class described, a work carrier, a tracer unit including a path following element, a path-forming unit, a bar rigidly supporting and joining said units, a car- 30 riage whereon said bar is mounted said carriage being movablewith'respect to the work carrier, and a side extensionon said tracer unit parallel to said bar and carrying said path-following element.

10. That method of producing cams which comprises outlining the cam on the element which is to form the completed cam, using said outline to position cutting means in conformity thereto and spaced therefrom while cutting am guide surface, then using said last-named sur-' faceas a guide for operating said cutting means in spaced constant relation thereto while said 'cutter forms the cam surface.

12. That method of producing cams which 55 comprises outlining the cam on the element which is to form the completed cam, cutting a guide surface in constant relation to said outline, and then using said surface as a guide while. cutting the cam. 60 13. A cam forming method which comprises laying out a cam on a blank, using thelayout line as a guide to form a master path on the same blank, then using the master path as a guide for cutting the cam path on the original 08 layout line. 14. That method of producing cams which comprises defining a master path on a blank, then moving said blank while cutting a path thereon,

, said cuttingbeing guided from said master path. 10

15. The process of forming acam by marking on a blank a series of central points for the cam path, ofisetting equally from those points a flexible element, forming said element to a smooth curve and securing said element to the blank. I

moving the'blank while;following said element with a follower of such size that as the follower bears against the element the center of the follower goes over the central points, at the same time cutting a path removed from the element.

16. In a mechanism of the class described, in

combination, a carriage, means for moving said carriage in a straight line, a cutter unit carried by said carriage, a tracer unit carried by said carriage, said tracer unit including a follower, electrical controls adapted for operation by said follower and governing the movement of said carriage, and means operatively adjacent said carriage for rotating a work piece and a pattern.

17. In a mechanism of the class described, in

combination, a carriage, means for moving said carriage in a straight line, a cutter unit carried by said carriage, a cutter included in said outter unit, a tracer unit carried by said carriage, said tracer unit including a follower, electrical controls adapted for operation by said follower and governing the movement of said carriage,

and means operatively adjacent said carriage for rotating a work piece and a pattern, said cutter, said follower, the line of movement of said carrier and radii of work piece and of pattern all lying in the same plane. 18. In a mechanism of the class described, .in

- combination, a work moving unit, a tracerunit and a path forming'unit, a carriage supporting both said units in operative relation to the work moving unit and in fixed relation to one another,

a follower upon said tracer unit, means for moving said carriage under guidance of said follower, said tracer unit and said cutter unit being interchangeable upon said, carriage, whereby a pattern path may be generated by said cutter in response to the action of said follower along or for puttingthe same out of engagement.

a layout line, and a cam surface may be generated along said layout line following the movement of said follower in said pattern.

19. In a machine of the class described, in combination, a carriage, a cutter and a tracer 5 mounted thereon,v work and pattern rotating means operatively adjacent thereto, mechanical means for moving said carriage with relation to said work and pattern rotating means, a follower upon said tracer unit adapted for coaction with a path on said work and pattern carrying means, and electrical means governed by said follower for selectively connecting said mechanical means in either direction with said carriage 20. In a machine of the class described, a source of power impulses independent of the direct guiding means, means for receiving relatively weak direct movements from a guide element and for transmitting power impulses from said source corresponding to such movements, path-making means directed and drivenby said source, and means for moving said path-making means by said power impulses correspondingly to said direct movements. 2

21. In a machine of the' class described, means I for moving a pattern and work in predetermined time and distance relation, sensitive pattern-following means, insensitive pattem-following means carrying said sensitive means, path-forming means in fixed relation to said insensitive means, a common mounting for said insensitive means and said path-forming means, power means for shifting said mounting, and'a control

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