US3160067A

US3160067A - Automatic cam cutting machine

Info

Publication number: US3160067A
Application number: US131458A
Authority: US
Inventors: Earl F Beezer
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-08-03
Filing date: 1961-08-03
Publication date: 1964-12-08
Anticipated expiration: 1981-12-08

Description

Dec. 8, 1964 E. F. BEEZER 3,160,067

AUTOMATIC CAM CUTTING MACHINE INI ENTOR. EARL F. BEEZ. E R

BY 2 JTTORNEY 1964 E. F. BEEZER AUTOMATIC CAM CUTTING MACHINE Original Filed Nov. 4. 1958 hees-Sheet 2 Q EARL F BEEZER M 34; ATTORNEY v 12 Sheets-Sheet 3 mfwfl l l hw lw @m Q mu@ll i if A 3 Dec. 8, 1964 la".v Ft BEEZER! AUTOMATIC CAM CUTTING MACHINE Original Filed Nov. 4, 1958 Q It Dec- 8, 1 64- E. E, BEEZER 331F600677 AUTOMATIC CAM CUTTING MACHINE Original Filed Nov. 4, 1958 12 Sheets-Sheet 4 a *1 1" If v INVENTOR. r I EARLEBEEZE'R I l 444A 5 H5 4 f BY 8 I ATTORNEY Dec. 8, 1964 E. F. BEEZER AUTOMATIC CAM CUTTING MACHINE (Jriginal Filed Nov. 4, 1958 12 Sheets-Sheet 5 IN VEN TOR.

EARL F BEEZQ ATTORNEY Dec. 8, 1964 AUTOMATIC CAM Original Filed Nov. 4, 1958 E. F. BEEZER CUTTING MACHINE 12 Sheets-Sheet 6 Zoe 696 k M 2 I I96 78 Zoo o 000 2 4 l l r74 I l \76 I 754 I as I I INVENTOR. EARL F. BEEZEF? e gmtww Dec. 8, 1964 E. F. BEEZER 3,160,067

AUTOMATIC CAM cu'mns MACHINE ori inal Fileql Nov. 4, 1958 12 Sheets-Sheet 7 INVENTOR.

5512 EARL F'- EJE'EZER BY /ITTORNEY Dec. 8, 1964 E. F. BEEZER 3,

AUTOMATIC CAM CUTTING museums Original Filed Nov. 4, 1958 12 Sheets-Sheet 8 i Q 2 l 74 11 ii i y L.. J I54 IN VEN TOR.

EARL F BEEZER Her. 16'

ATTORNEY Dec. 8, 1964 E. F. BEEZER 3, 6

AUTOMATIC CAM CUTTING MACHINE Original Filed Nov. 4, 1958 12 Sheets-Sheet 9 I 2 3'6 9 '7 n 322 k, d h I v m I L o F3, 7 Ir 9 I 322 I l 1 1| G: f

Iii IL 320 M ace INVEN TOR.

EARL F- B R M QWMK ATTORNEY Dec. 8, 1964 E. F. BEEZER 3,160,067

AUTOMATIC CAM CUTTING MACHINE ori inal Filed Nov. 4, 1958 12 Sheets-Sheet 10 FALL owsu. FALL RISE sToP I V 3 WELL 200 STOP nu.- nw su. STOP 362 owzu.

STOP 1250 s'rAR'T START on STOP STOP OFF- SPEED CONTROL INVENTCR.

EARL F BEEZER Dec. 8, 1964 E. F. BEEZER 4 3, 60,067

' AUTOMATIC CAM CUTTINGMACHINE Original Filed Nov. 4. 1958 12 Shee ts-Sheet 11 INVEN TOR.

EARL. F. BEEZER BY W ATTORNEY 1954 E. F. BEEZER 3,160,067

AUTOMATIC CAM cuw'rmc MACHINE Original Filed Nov. 4, 1958 12 Sheets-Sheet 12 w ms [a b2 ms SELECTOR INVEN TOR.

EARL. F. BEEZER ATTORNEY Unitedstates Patent Oflice 3,1665%7 AUTOMATIC CAR/i CUTTING MACEHNE Earl F.- Beezer, Para'mus, N5. (Zontinuation of application Ser. No. 771,775, Nov. 4, 1958. This application Aug. 3, 1 961, Ser. No. 131,458 15 Claims. (Cl. 9013.4)'

This invention relates in general to cam cutting machines and particularly to a new and useful cam cutting machine adapted to cut cams of various sizes and shapes by making simple mechanical adjustments and without requiring the making of a master cam.

In the mass manufacture of cams it is usual to first make a so-called master cam. This cam is made by slow precision cutting methods in which the machine cutter is adjusted during each minute period of cutting 'in order to achieve a master cam which has the desired rise, fall and dwell contour characteristcs throughout its angular cam surface extent. With some lattertype machines instead of making a master cam it is necessary to make a so-called master tape. The master tape which is made presents a control surface which is detected by electronic apparatus to actuate a cam cutting machine during the fabrication of subsequent cams.

it should be realized that the majority of cams are made on an individual basis, i.e., where individual cams are made by intermittently rotating the work on a milling machine table through a small angle of rotation by means of a dividing head, then moving the cutter into or away from the work to thus produce a rough scalloped surface which is subsequently filed smooth. For positive motion cams, where filing is usually impractical, or where more than one cam is required, it may be necessary or desirable to make a master cam first and thereafter make the remaining cams from the master cam by a tracing mechanism. Master cams are also usually required for plate cams where a large number of duplicate cams are required.

The present invention provides a device for cutting, grinding, milling, shaping, etc. of cams or similar mechanisms by making simple settings in the machine to effeet the complete manufacture of individual cams. The invention provides a completely automatic device for effecting the complete contour machining of the cam surface without first requiring the making of a master cam. The invention includes a simple pantograph type mechanism and a plurality of predeterminably operable machine guiding cams to effect the final cutting of the cam with contours imparted thereto in accordance with the usual cam motions such as constant velocity, parabolic, harmonic, cycloidal, etc. By making proper settings in the set up of the machine it is possible to move the pantograph mechanism into operative association with one of the machine cam profiles to obtain the desired cam motion surface on the cam being manufactured.

A machine constructed in accordance with the invention provides means for machining an infinite number of cam sizes and shapes by merely making initial settings on the machine. With such a machine no engineering computations of a cam chart is required. The only data necessary to machine the cam is: 1) the total rise or fall required in thousandths of an inch; (2) the number of degrees for such rise or fall and (3) the characteristic curve which should be imparted to the cam during such rise or fall (constant velocity, parabolic, harmonic, cycloidal, etc.) and (4) the angular extent of the dwell portions on the cam (if any). It is possible to conveniently set this data into automatically operable mech anisms on the machine and thereafter permit complete automatic machining of the entire cam.

A device constructed in accordance with this invention is extremely accurate and is capable of cutting all of the usual variations in cam sizes and shapes by making i the initial machine setting for the complete manufacture' of the cam or by setting the machine to perform a complete machining step such as a rise or a fall and thereafter resetting the machine. A feature of the inven- A feature of the invention is a provision for trans mitting motion to the cam cutter or grinder to compensate for any errors which may be introduced due to the fact that the cam operates a lever crank or rocker arm which oscillates through a certain arc. The cam cutter or grinder of the present invention is provided with a mechanism to mechanically reproduce the movement of the cam follower on :a lever during the cutting of the cam surface so that the surface will be correspondingly altered to compensate for the error of cam follower positioning. V

A feature of the present invention is that the machine may continuously cut or grind hardened cams without requiring filing or other finishing procedures to remove With the usual cam cutting machine, where scallops. a master cam is cut, filing to remove scallops on the master cam is still necesary to achieve aprecise cam surface. Thus the master may have inherent errors itself. This is an important consideration where steep rises or falls occur on the cam surface (so-called high pressure angle). In this latter case, the radial change for one degree is quite appreciable and if the cam cutting mechanism is not extremely accurate, undercutting may result or long scallops may appear. In some cases, it is not possible to remove the scallops with accuracy in these areas so that the finished cam will not produce precisely the desired curve. With the high speed cams so essential in many of todays mechanisms, it is of the utmost importance to have refined accuracy especially where moderate or severe throws is encountered, since inaccuracies produce critical areas on high speed cams By incorporating split linear ball bushings throughout the mechanism for the linear slide motions, the apparatus can be adjusted for zero shake, there is a minimum amount of rolling dynamic friction at slow feeding linear speeds and there is very little danger of particle contaminations which would produce inaccuracies, since the bushings provide integral wipers to exclude machine chips and grit.

Accordingly, it is an object of this invention to provide an improved cam cutting machine.

A further object of this invention is to provide a cam cutting machine having means for cutting cams of various sizes and shapes without employing the use of an individual master cam.

A further object of this invention is to provide a cam cutting device including means for setting the mechanism of the machine to cut a complete cam of predetermined size and shape. I

A further object of this invention is to provide an extremely accurate cam cutting machine.

A further object is to provide a machine which requires Patented Dec.8, 1964 1 charts, for producing a finished cam.

A further object of. this invention is to provide a camcutting machine including a pantograph mechanism for moving the Work table and means for guiding the pantograph mechanism for translational movement in accordance with a preselected motion profile.

A further object of this invention .is to provide a cam machining device including means for machining acam to a desired contour and correcting this contour to compensate for the arcuate oscillation of a follower which will be used in association with such cam.

A further object of this invention is to provide a cam cutting device which is simple in design, rugged in construction, economical to manufacture and highly accurate.

' A further object of the invention is to provide a highly accurate automatic cam cutting device including a pantograph mechanism in which movement of the mechanism over a tracing point is magnified :at the cam cutting locations so that accuracies over five times the accuracy of the generating surface may be obtained.

For other objects and a better understanding of the invention,,reference may be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a left side elevation of a milling machine having an automatic cam machining fixture constructed in accordance with the invention;

FIG. 2 .is a horizontalsection taken on the line 2-2 of FIG. 1;

FIG. 3 is a rear elevation of the automatic cam milling fixture shown in FIG. 1 but indicating the rotary work table arranged in a vertical position for machining a cylindrical cam and indicating the alternate horizontal position of the work table, in phantom, for machining plate or disc cams;

FIG. 4 is a vertical section taken on the line 4--4 of FIG. 2;

FIG. 5 is a fragmentary plan view partly in section of the pantograph control mechanism taken on the'line 5- -5 of FIG. 3; e

FIG. 6 is a vertical section taken on the line 6-6 of FIG. 5; i

FIG. 7 is a vertical sectiontaken on the line 7-'7 of I FIG. 5; 7 FIG. .8 is a fragmentary vertical section taken on the line 8-8- of FIG. 2; a

FIG. 9 is a vertical section taken on the line 9-9 of FIG. 2;

FIG. 10 is a fragmentary vertical section taken on the line 1010 of FIG. 2 and indicating the notched cam timers;

FIG. 11 is an enlarged vertical section taken on the line 11- -11 of FIG. 2 of the adjustable diameter ball bushing;

FIG.- 12 is an enlarged fragmentary vertical section taken on the line 12-42 of FIG. 5;

FIG. 13 is a verticalsection taken on the line 13'13 of FIG; 2 indicating the reversing mechanism;

FIG. 14 is a section taken on the line 14-14 of FIG. 13;

FIG. 15 is a horizontal section taken'on the line 1515 of FIG. 1;

FIG. 16 is a fragmentary end elevation taken on the line 16-16 of FIG. 15;

FIG. 17 is a somewhat schematic view of a pivotally mounted lever follower and cylindrical cam showing the inaccuracies which would beintroduced by the arcuate motion of a cam-follower;

FIG. 18 is a'section taken on the line 18-18 of FIG. 19;

FIG. 19 is a transverse section through the dwell control setting knobs of the control panel;

FIG. 20 is a perspective'view of the rotary solenoids shown in FIG. 18;

4 t FIG. 21 is a perspective view of the magnetic clutch shown in FIG. 22;

FIG. 22 is a vertical section on the line 22-22 of FIG. 2, indicating the magnetic clutches and bearing supports;

FIG. 23 is a vertical section taken on the line 2323 of FIG. 2 of the control microswitch;

. FIG. 24 is an elevation of the panel control for the automatic cam milling machine indicated in the drawings;

FIG. 25 is a somewhat schematic plan of the work table operating mechanisms; and

FIG. 26 is a schematic wiring diagram of the automatic controls.

Referring to the drawings, in particular to FIG. 1, the invention as embodied therein includes a milling machine generally designated A including a main frame B containing the usual milling driving mechanism (not shown). Mounted for transverse reciprocable movement on the main frame A is a cutter or grinder head and a slide C the end of which carries. the cutter or grinder driving mechanism D. A Work table Eis mounted for vertical reciprocation on the mainframe B, and it in turn carries a transversely reciprocable table F and a laterally reciprocable table G. Control handles 10, 12 and 14 control the respective movements of the vertically reciprocable table E, a transversely reciprocable table F and a laterally reciprocable table G.

.In' accordance with the invention, an automatic cam cutting mechanism generally designated H is secured to the table G as by

bolts

16, 16. In the present embodiment, the automatic cani cutting mechanism H includes an electric driving motor and complete operating parts which operate independently of the cutter driving mechanism D. It should be appreciated that the machine could be fabricated as a complete milling machine unit in which the driving mechanism for both the cutter and cam cutting mechanism H is operated from a single power source or it could be fabricated as a separate cutting machine in and of itself. The automatic cam cutting mechanism H advantageously includes a swing arm adjusting mechanism generally designated I which is mounted on the frame B and is provided for compensating for cam follower. swing arm eifect.

Referring to FIGS. 2, 3 and 25, the automatic cam cutting mechanism H includes a combination driving electric motor and variable speed mechanism 18 with an output shaft 20 having a sprocket pulley 22 which drives through a chain or, toothed belt 24 to a pulley 26 mounted on a main drive shaft 28. The main drive shaft 28 is mounted at one end in an end bearing 30-which projects outwardly from an end frame member 34, the latter being atfixed to a base plate 36, and, at the'opposite end, in the housing of a reversing mechanism generally designated 37 (FIGS. 2, 13, 14 and 25). The reversing mechanism 37 includes an output gear train indicated 38a, 38b and 38a and an input gear, train indicated 29a, 39b, 39c and 39d, connected to an output continuation shaft 40. The direction of rotation of the gears 38a and 380 is identical and therefore the direction of rotation of output shaft 40 is determined'by gears 39b, 39c and 39d.

At an appropriate time in the machine cycle when it is necessary to reverse the movement of the translation cam assembly 79 in a mannerto be described more fully hereinafter, the output continuation shaft 40 must be reversed. An electrical control is therefore energized tov idler gear to the train, therefore changing the direction of rotation of all the gears in the train except the gear 39a which is connected to the shaft 28. The shifter arm;

41 is actuated by a rotary solenoid 42. The solenoid 42 is actuated by electrical control mechanism in a'manner to be described more fully hereinafter. Thus, rotation of the shaft 28 may impart rotation to the shaft. 44. in. one.

direction or the other under the control of the solenoid 42.

The shaft 40 is connected through a magnetic clutch and bearing assembly generally designated 52 (FIGS. 21, 22 and 25), to a continuation shaft 54. The magnetic clutch 52 includes the usual mechanism for effecting rotation of the output shaft 54 in response to rotation of the shaft 40 under an electrical control connected by leads 55, to be described more fully hereinafter.

The shaft 54 extends through a predetermining notch cam device generally designated 56 in FIG. 10. The device 56 includes a solenoid 57 having a plunger arm 58 which is biased toward the surface of a disc cam 59. The disc cam 59 has a unitary notch portion 60 which, when engaged with the plunger arm 58, correlates the starting and stopping of a machined operation. The device 56 works in conjunction with the magnetic clutch 52 to synchronize the starting and stopping of a controlled machine operation. The magnetic clutch circuit is provided with a variable potentiometer control to establish the amount of magnetic clutching engagement and slip. The said variable potentiometer is set to control the clutch 52 and permit slippage once the pawl plunger arm 58 engages the notch 60 of the disc cam 59. The control is such that there is no slippage of the clutch during any machining operation. It should be realized that the magnetic clutches may be replaced by mechanical clutches and actuated at appropriate times to achieve the same result. in the arrangement of the present invention, the magnetic clutch 52 is de-energized after the notch cam is locked by the pawl plunger arm 58. Therefore, the clutch 52 will slip for a short time after the engagement until it is de-energized. This insures positive engagement of the notch cam by the plunger arm and obviates the possibility of any cumulative error, however small, in the machining operation by the shaft 54 coming toa constant reference point at the start and termination of every machiring sequence.

Referring to FIGS. 2 and 25, the output end of the shaft 54 is provided with a gear 51 which drives through a gear 62 affixed to a screw shaft 63, rotatably mounted in suitable hearings in the end frame member 34 (see FIG. 8). The shaft 62 is mounted in

bearings

64 and 66 in the upstanding end frame members 34. The central portion of the shaft 63 isprovided with a ball screw threaded portion 68 having a carrier 70 axially movable therealong and which is provided with a central ball screw race portion which engages the ball screw portion of the shaft 63 and is drivingly moved thereby. Two ball nuts 69a and 691) are axially preloaded against each other to remove end play which might occur due to elasticity of balls and races and thereby increase accuracy.

The carrier 70 is also guided by

space guiding rods

74 and 76. The arrangement is such to permit the carrier to move transversely in respect to the position of the cam being machined and effect uniform precise longitudinal movement of the work table under the control of a pantograph mechanism in response to traverse of a follower 192 of the pantograph mechanism over the surfaces of one of a plurality ofmotion cams held by the carrier 70.

Referring to FIG. 9, the carrier, 70 in the present embodiment is provided with sufficient spacers 77 and retaining plates 78 and 80 to accommodate three sets of control cam profiles 88, 90 and 92, each of which is contoured to give a different type of motion for a rise or a fall surface to be cut on the cam or as in the present in stance, they are of a single curve'but graduated in size to accommodate cams of varying rise and fall dimensions. These cams control the rate of'longitudinal movement of the work table. The angular extent of such a rise or fall as machined into the cam is controlled by the speed of rotation of the table upon which is mounted the cam to be machined in a-manner to be described more fully hereinafter.

Great variations in the number of rise and fall curves 6 which may cut into a cam can be achieved with proper selection of control cam profiles. Three control cams of varying dimensions are deemed suflicient to cover the usual full range of rises and falls originally encountered in cam application work. In the present embodiment, three cams are adequate in the space allotted and for the purposes desired. A stock set of three cams may be also chosen for the characteristic type of motion for which cams will be cut, such as a set for straight line, parabolic, cycloidal or any type of motion. The control earns 88, and 02 are removable and, of course, cams having contours to permit machining of other motion rises and falls on the cam being cut may be supplied with each machine.

In order to illustrate the capacity of the three

cams

88, 90, $2, the machine dimensions may be such as to establish a reasonable maximum cam throw of 5.000". The following tabulation gives the various rises of the translational cams to suit this established maximum.

Machining Rise on Range Translational Cam It 'must be remembered that these stated ranges in no.

way restrict the capacity of the machine but are herein stated as being representative values,

The opposite end of the shaft 28 is provided with a helical gear 94 (FIGS. 2 and 25) which meshes with a similar helical gear 96 afixed to a main work table driving shaft 03. The work table drive shaft 98 is supported by a bearing 100 at one end and at the opposite end, it

is supported .by a bearing 102 of a clutch and bearing assembly 103 (FIGS. 21 and 22) which is similar to the assembly 52.

A continuation shaft 104 extends outwardly from the magnetic clutch 103 and connected to a predetcrmining notch cam device 105. The device 105 is similar to the device 56 illustrated in FIG. 10. The continuation shaft 10 is splined as at 06 on the other side of the device 105 and extends through a speed change gear assembly generally designated 107. p

The change gear assembly 107 includes a large number of gears which can be shifted into various meshing ratios which are readily obtainable for transmission of rotation able movement to the work table. These ratios, outlined as sub-divisions of 360 on the control face, are selected by moving two

lovers

132 and 134 to appropriate positions as indicated by markings on the housing 107 (not shown). Since a great majority of cams in use are symmetrical in respect to the increment of rise or fall as well as to the angular sector over which the rise and fall takes place, the setting of the change gear-s may be. left un changed for the complete machining of the cam. Of course, the angular extent of rise and fall and'intermcdiate dwell must equal 360.

The change gear box 107 is connected to a work table or work carrier generally designated 136, FIGS. 2, 4 and 25, which isslidably supported on two laterally spaced side .bars 138 and 140 which are rigidly aflixcd in the end 1 frame member 34 and a similar transversely spaced end port near the center of the corners by adjustable diameter split ball bushings gencrally designated 148 and indicated in detail in FIG. 11.

Radial clearance between the bushings and the slide bars can be adjusted for zero shake by tightening the screw 150 and removing an appropriate thickness of shim stock 151 so as to effectively reduce the bore diameter of the split ball bushing housing 148. By providing ball bushings of such type, the apparatus will operate with zero shake and a minimum amount of rolling friction. This eliminatesany tendency of the work carrier to bind or to undergo alternate conditions of slide and stop which would introduce inaccuracies however small as they may be. A slide and stop effect is sometimes introduced in sliding mechanisms of this type as a result of the difference in the coefficients of static and dynamic friction. This is especially true when the machine is operating at slow rates of work feed, and conventional machines The present construction permitsv The arms 182 and 180 are slidable within their respective holding sockets 176 and 178 but they are locked in position therein by locking

screws

191, 191. The arms 182 and 180 are slidable only to permit their removal and replacement by arms of different length, if desired.

The assembly is slidable along the rod 164 and each arm 180 and 182 is adjustably positioned and pivotally connected to associated

pantograph arms

188 and 189,

a respectively. The arm 188 is pivotally mounted to a por- The work carrier 136 includes a central work carrier support or a rotary table 149, FIGS. 2, 3 and 4, having T-slots 150' in a top face for attaching the cam blank to be machined. The rotary table 136 is adjustably mountable so as to .be positioned in the horizontal position indicated in FIG. 2 and FIG. 3 for machining a disc or plate'type earn 152 indicated in phantom, or it may be positioned in a vertical position as indicated in FIG.'3 for the machining of a cylindrical cam 154. Referring to FIGS. 2, 3 and 25, the rotatable table 149 is rotated by a shaft 156 driving through suitable gearing (not shown) which is connected by a coupling 158 to an output shaft 160 of the speed gear housing 107.

To change from the position of the work table as indicated in FIGS. 2 and 4 to the position indicated in FIG.

3, the coupling 158 is loosened and the work table is mounted in an upright position and similarly driven by the output shaft 160. The change gear assembly 107 is slidable along a mounting plate 161 and may be positioned in alignment with the shaft 156, when the rotary table is mounted in a vertical position (FIG- 3, solid lines) as well as when the table 149' is positioned in a horizontal position (FIG. 2, solid lines).

In accordance with the invention, the linear or transverse motion of the work table 149 is obtained by a motion of a novel pantograph mechanism generally indicated at 162 (FIGS. 1, 2, 4, 5, 6 and 7).

The pantograph mechanism 162 includes an adjustable screw rod 164 mounted in depending spaced bearings168 and 170 at each end of one side of the work table 149. The screw rod 164 is provided with a right angle pantograph holding bracket generally designated 172 which is provided with hubbed portion 174 having an internal screw which engages the threaded portion of the rod 164.

The pantograph holding bracket generally designated 172 is provided with pantograph arm holding sockets 176 and 178 which receive corresponding pantograph arms 180 and 182 which are pivotally connected at 184. The arms 180 and 182 are maintained in their right angle relationship during set-up, by the bracket 172.

The bracket 172 includes a bottom plate 185 which is rigidly secured to the holding socket 178. The opposite edge of the plate 185 is provided with a pair of spaced aperturcs'which receive locking

pins

186, 186, one of which holds the holding socket 176 in a position at precisely right angles to the holding socket 178 for concerted right angle relationship movement during set-up and adjustment of the hubbed portion 174 along the screw 164.

tion of the frame at 190 while the arm 189 is provided with a roller follower 192 at its outer end.

The roller follower 192, FIG. 9, is adjustably positioned between a substantially U-shaped supporting member 194, FIG. 6, affixed to the end of the arm 189. The, follower 192 is mounted on a pin 196 which extends through each FIG. 6, affixed to the end of the arm 189. The follower positioned to align vertically with one of the

cams

88, or 92, FIG. 9 and FIG. 2. The U-shaped member 194 is biased in a direction to urge the follower 192 into. operative association with one of the cam members by pin extension 196 which is connected at each end to tension springs 200 and 202.; The other end of each of the springs is afiixed to a pin 204 which is held in a supporting bracket 206 affixed to the end frame member 34.

Each of the arms 188'and 189 (FIG. 5 and FIG. 12) is pivotally connected and supported for pivotal movement in an upstanding bearing hub 208 of a rod 210, the

latter being supported in a cylindrical ball bushing housing 212 and mounted on thrust ball bearings 214 and 215, in order to permit free piovtal, rotatable and translational movement of the pivot point 216 at the juncture of the arms 188 and'189 without misalignment of the mechanism.

During set-up, arms 180 and 182 are slidable within sleevesf 201 and 203 on associated

arms

188 and 189. The arms 180 and 182 are clamped in position in relation to sleeves 201 and 203 once the pantograph has been set up by clamps 205 and 207. The arms 180 and 182 are also axially shiftable in respect to associated

arms

188 and 189 in slide members 209 and 211 and are anchored once they are positioned by locking

clamps

213 and 215, respectively. Clamping

levers

197 and 199 are provided to clamp the bushing 174 in position on the screw 164 once the pantograph ratio has been set.

The follower 192 is urged into association with any one of the desired three

cams

88, 90 or 92 (FIG. 9). When the cam in association with the follower is moved by rotation of the shaft 63 laterally in a direction transverse to the direction of movement of the work table (FIGS. 2 and 25), the pantograph mechanism imparts longitudinal movement to the work table 136 in proportion to the movement of the follower. over the cam surface. In order to adjust the pantograph mechanism to magnify or reduce the motion transmitted by the mechanism to the i work table and thus vary the amount of rise and fall cut into the cam, there is provided a calibratedscrew shaft 216,'FIG. 2, which is mounted in hearings in the frame which is attached to the work carrier 136. The calibrated screw shaft 215 is provided with a helical gear (not shown) which meshes with a helical gear 217 to move the pantograph bracket 172 longitudinally in response to rotation of a handle 218 (FIGS. 2, and 5). An indicating scale 220 over which an internally threaded pointer nut 221 is moved indicates the extent of work table movement for a given movement of the roller follower 192 by the

cams

88, 90 and 92. This setting is established prior to the start of the machining operation for the desired amount of rise or fall. Rotation of the handle 218 is effective to move the bracket 172 longitudinally along the slide rod 164. The holding bracket effects movement of arms 180 and 182 in the right angle relationship during set-up. A slide bar is rigidly mounted in depending portions of the work carrier 136 and provides a rigid support for the pantograph at pivot points 184 and 196. It is essential with such a pantograph mechanism that the three pivot E points 190, 184, 196 remain in a straight line through their centers. The mechanism can be set to an extreme position indicated in phantom in FIG. 5. The pantograph may be positioned to give an infinite variety of magnifications or reductions of the motions indicated by the

cams

88, 2t and 92 in order to achieve the desired cam surface on a cam being machined. By varying the speed of rotation of the work table as well as the speed of tranverse movement, it is possible to machine a cam to precise dimensions by a stationarily positioned rotating cutter 34. When swing arm unit is employed, this cutter will move slightly as determined by arcuate travel of lever follower in a manner to be described more fully hereinafter.

In cam operated devices, the cam follower is usually mounted so that it oscillates in a circular arc, being constrained to do so by a lever or rocker arm which turns or oscillates on a rocking shaft. In such oscillatable arm mounted followers (FIGS. 15 and 17), the follower moves oif center as the arm oscillates as indicated in FIG. 17 and FIG. 15. The greater the angle of oscillationof the follower mounting arm, the greater the amount of off center movement 236 and hence variation in follower movement in response to the cam contour. In accordance with the present invention, the errors introduced by the manner of mounting a follower on an oscillatable lever arm are minimized, and to a practical extent eliminated.

By referring to FIGS. 1 and 15 to 17, inclusive, there is indicated mechanism for compensating for movement of the follower on an oscillatable lever arm by shifting the positioning of the rotating cutter 234 sof the cutter head and slide C. The cutter head and slide includes a sliding ram 273 (FIG. 1) which is controlled for compensatory movement in direct proportion to the extent of the radius of movement of the follower arm with which the cam being machined will be associated. The ram 237 is provided with a depending laterally extending lug 238 which has a transverse slot 239 which accommodates an upstanding roller 240. The roller 249 is connected to mechanism to move the roller the precise amount of variation caused by mounting a follower on an oscillatable lever arm to effect similar movement of the ram 237 and cutter 23 while the cam surface is being machined. This distance 236 may be slight, and as indicated at FIG. 17, in order to set the amount of compensation the roller 240 is set at a distance from a central pivot 2 54 of a pivotal setting arm 245, an amount equal to the length of the follower mounting arm. This is set by a hand wheel 246 for rotating a calibrated shaft 248 to position the roller 24!) at a distance from thepivot 244 corresponding to the radius of the follower from its pivot. A worm 250 is mounted on a transversely extending shaft 252 having a hand wheel 254 for rotatably positioning the arm 245 which is revolved by the worm 250 through a worm gear segment 255 at the end thereof. Rotation of the hand wheel 254 is effective to change the angular position of the arm 245 and hence the roller 24%). This angle corresponds to the /2 angle through which the cam follower arm 235 must travel in its actual machine application. It is read directly on the scale 247 provided (FIGS. 1 and 16) and is attached to the pivot base 249. Movement of the ram 237 during the machining operation is effected by the Worm 250 driven by a pair of helical gears with crossed axes 258 which in turn receive power through a speed change gear mechanism 26%. An input shaft 262 is connected to the speed change gear mechanism 269 and is connected through a lateral displacement coupling 264 to the shaft 62. A magnetic clutch 2H3 (FIG. 15) is normally provided as indicated in FIG. 15 to permit disconnection of the swing-arm compensating device when cams are milled which will not be mounted on a rotatable follower arm and during set-up.

In the present embodiment, the cams 88, 9t) and 92 are chosen so that the pantograph mechanism is used to magnify the movement of displacement of the follower 192 by the cams. The minimum magnifications for any 10 one translational cam is shown in solid lines in FIG. 5 while the maximum magnification is shown in phantom. The range is infinitely variable. However, for practical use, the hand wheel 218 has agraduated scale 220 reading directly to within 1,000 of an inch. Additional control cams, such as the control earns 88, and 92, which can also be mounted directly on the assembly would make it possible to magnify and supplement the ranges provided by the three cams shown in the embodiment. Since control cam surfaces representing Various cam surface controlled movements such as constant velocity, harmonic, parabolic, cyoloidal, etc. may be used, any surface characteristic curve including special profiles can be obtained by the apparatus. Since the majority of such curves represent variable functions, the pantograph provides the constant parameter necessary to translate these curves into an infinitely adjustable ratio. For the position shown in solid lines in FIG. 5, the accuracy of the transmission of movement to the work table through the pantograph would be approximately 25 greater than that of the control cam outline itself. For the position shown in phantom, the accuracy would be five times as great. This means that an error of 1,000 of an inch on the control cam would only transmit an error of 2 ten-thousands of an inch into the cam being machined in the latter case.

This makes the mechanism of the present invention suitable for extremely accurate requirements for cam manufacture.

The procedure for initially setting up the pantograph linkage prior to a cam machining operation is as follows:

The clamping levers 295, 2%7, 213 and 215 holding the pantograph arms are released but the right angle between arms 18% and 182 is maintained by the plungers 186, 86. Clamping

levers

197 and 199 are also loosened so as to allow the generating pivot located on the bracket 172 to be moved along the axis of the slide rod 164 by means of hand wheel 218, to obtain the correct pantograph magnification setting. This setting may be accurately read on a graduated dial 229. All clamps are then retightened and the pantograph mechanism is ready for operation.

The use of a split ball bushing such as 198 permits sliding movement of the tracer roller during machining with very little restraining friction and at the same time efiects zero shake during operation. The tracing roller or follower 192 is constrained to move positively in a linear direction by means of an adjustable split ball bushing 266 (FIG. 5) similar to that indicated in FIG. 11. Theball bushing 266 rolls with zero shake on the slide bar extension 268 which is prevented from flexing under reaction forces induced by machining operation by backing rollers 27!? and 272 which contact a rail 274 alfixed to the ball bushing 26%. The rollers 27ti and 2.72 are mounted on the bracket 273 affixed to the frame.

Referring to FIGS. 18, 19 and 24, a control panel 30% includes two dwell setting knobs 3M and 304 which are rotatable to displace

contacts

306 and 308 of a predetermining device generally designated 31% to set the angular extent of a dwell being machined on a cam during a first and second dwelling machining operation. During the dwell periods, the mechanism is controlled to maintain the pantograph mechanism at its position which it may be at during the start of the dwell period in order to cut the cam without changing the radial dimension of the surface being cut. At the appropriate time in the cycle for the starting of the dwell, as regulated by relay mechanisms controlled by a selector knob 312 in a manner to be more fully described hereinafter, a cam operated switch 31 in FIGS. 25 and 23, is arranged to energize a solenoid 316,

FlG. 18, to intermittently drive a pawl S18 affixed to an arm thereof and a ratchet wheel 32f) counterclockwise. The ratchet wheel 52% is rotatably mounted on a shaft 322, FIGS. 18 and 19, in the control panel and contains the contact 308. Fixed contact 306 is attached to a fixed frame 307. The ratchet wheel 329 is moved one tooth 11 per degree of rotation of the rotary table 149. In this manner, the intermittently moving contact 308 approaches the fixed contact 396 as the dwell portion continues during the rotation of the rotary table. At the end of the dwell cycle, the contacts will engage and close an electric circuit to signal the. end of the dwell phase and initiate a succeeding sequence of events to start the next rise or fall cam machining cycle. A second dwell, if required, would be accomplished in a like manner by a similar device to that indicated in FIGS. 18 and 19, but attached to the second dwell knob'on the control panel. Only one device is illustrated and described, however, the other being similar.

Solenoids

322 and 324 are for the purposes of resetting the predetermined knob 394 at the completion of the finished cam or prior to the start of making another cam. When the solenoid 324 is energized, a counter-rotational pawl 326 connected to the solenoid is moved out of engagement with the ratchet 329. The solenoid 322 when energized moves a cam member 328 to move the pawl 318 out of engagement with the ratchet wheel 320. These are energized at the same time by a switch 303 while manually resetting the dwell knobs 392 and 304 for a succeeding machine operation. The switch 314 is actuated four times per revolution of the shaft 160 to account for the fact that the rotary table turns four (4) degrees per revolution of the shaft 160 or for each one-quarter turn of the shaft 160 the rotary table turns one (1) degree. Referring to FIGS. 24 and 26, there is indicated the wiring diagram for effecting the electrical movement of the machine parts in accordance with the settings on the control panel (FIG.'24). The control knob 312 includes seven settings which permit complete automatic machining. for a fall, dwell or rise as indicated at the control knob settings. If, for example, a fall, rise and stop sequence of operation is desired, the control knob is set as indicated in FIG. 24 and the dwell knobs 302 and 304 are set at the zero location since no dwell is indicated. If it is desired to set the machine for operation in which cutting is to be done during a dwell for zero radial displacement of the cam cutter, the first dwell knob 304 is set for the desired angular extent of the dwell to be machined on the surface of the cam. If it is desired to machine a cam which will normally be mounted on a pivotal cam follower arm, the mechanism to compensate for the swing arm effect is switched on and appropriate adjustments'for the swinging arm adjustment setting by the hand wheel 246. There is an overall machine speed control knob indicated at 330 (FIG. 24) which is connected to motor 18 to change the motor speed to provide a variable rate of feed of the work into the cutter or grinder for optimum machining feed con-. sistent with good shop practice. Motor start and stop buttons as well as machining start and stop buttons are also provided.

The wiring diagram indicated in FIG. 26 includes electrical controlsfor causing the machine to produce the movements which have been previously set on a control panel. The device is flexible enough to permit its use for machining a complete fall-dwell-rise dwell cycle as well as single fall dwell or rise machining portions of cutting.

The wiring diagram indicated is for use with a machining motor for exampe, which drives the cutter or grinder as an integral part of a milling machine upon which the fixture is mounted. Spindle speed can be regulated from a separate control. The push buttons for starting and stopping the fixture drive motor 18 (FIG. 3) which are indicated in the control panel are designated by the legend motor. The push buttons marked machine stop and start initiate the controlled sequence of machining a cam blank. Shaft 28 is driven by a timing sprocket 26 through a toothed belt 24 (FIG. 3) and turns continuously driving the shaft 98 by means of the helical gears 94 and 96. At appropriate times in the machining cycle the

shafts

54 and 63 as well as the shafts 1% and 156, FIGS. 2 and 25, are optionally by means of magnetic clutches control system which cooperates to automatically produce a completely finished cam.

After the initial settings and adjustments have been made to the mechanical parts, i.e., setting of the pantograph for the desired rise or fall, selectingthe appropriate characteristic curve, etc. on one of the cams 83, or 92, the particular machining sequential cycle is selected by rotating the large knob 312 to the appropriate cycle. At the first location the knob would provide for automatic machining during a sequence of a fall, a dwell, a rise, a dwell and the stopping of the machine. Since. this is the most comprehensive machining operation of all those listed, it will be described in detail. In this instance, there is a first and second dwell and therefore the value of the desired angular extent of each dwell is set on the appropriate knobs 3%)2 and 304. Assuming that the swing arm is to be used, the swing arm on button is pressed after setting the arm for correct radius and angular swing arm, to energize and couple the magnetic clutch indicated 263 in FIG. 25. The work to be machined is then moved into the cutter by means of the milling machine hand wheel 10, 12 and 14 (FIG. 7) to a point corresponding to the high point of a cam. The fixture is now ready for continuous 360 machining for the cycle mentioned above.

Upon starting the work feed motor 18 (FIGS. 3 and 26) relay'K13 is energized to provide'a motor holding circuit. As shown in FIG. 26, a set of normally open contacts K16 in the milling machine circuit must be closed to insure that no machining will take place unless the cutter motor is operating.

The machine start switch is pressed to initiate the events that take place as in sequence as follows:

As soon as this is done, a relay Kx is closed to release all latch type relays which may have their normally opened contacts closed due to a previous machining cycle. Such relays include two actuating coils or solenoids, one for on and one for off, and the relay is latched when a solenoid is actuated. The latching causes a de-energizing of the coil current. At the same time, a relay K14 is latched for the purpose of providing a holding circuit for the variable speed motor 18. Since a limit switch S31 is closed, at this time relays K1 and K2 will be latched immediately to energize the electromagnetic clutches B1 and B2. Limit switches S31 and S32 are provided at each end of the shaft 68 to control the sequence of timed events that occur at the completion of the transverse movement of the translational cam assembly.

A short while thereafter. (when K1 has latched) relay K3 and K4 will latch to energize solenoids both indicated 47 to withdraw their respective locking pawls 58 from the slots in the notched cams 59. It will be noted that the

clutches

103 and 52 are energized previous to the release of the locking pawls. The clutches are so energized to insure that the locking pawls 58 cannot be retracted prior to energization of the clutch; thus they can slip under load, such as when the locking pawl is in the slot at 60 indicated in FIG. 10. In addition, this causes the clutch coils to be fully excited when release of the pawl occurs. A variable potentiometer permits adjustment for optimum setting of slip when the locking pawl has engaged the notched cam but not insufiicient to permit slippage during a machining cycle.

A withdrawal of the locking pawl immediately initiates the combined movement of the translational cam assembly and the rotary table to machine the fall portion of the cam to be machined.

Just prior to the completion of the th turn of the

control shafts

28 and 54, and 98 and 106, the limit switch a 13 S32 will close and immediately release relays K3 and K4 to deenergize the solenoids 57 and cause the locking pawls to ride on the periphery of the notched cams 59. Thus the pawls 58 will ride on the periphery of the notched earns 59 under spring tension until engaging their respective slots 60. This stops the rotation momentarily of shaft 54 as well as shaft 106 at precisely 120 turns. This is due to the fact that in this embodiment a five H.P.I. (threads per inch) ball screw extending for twelve inches requires 60 revolutions for a complete traverse of the translational cam assembly. Due to a 2 to 1 reduction in the drive gears 58 and 60, 120 revolutions of the control shafts are required. Further speed changes are effected in the selected

change gear housings

107 and 260. The change gears modify the 120 total angle into a further speed ratio for the particular angle of fall in the cam to be machined.

Approximately of a revolution of control shafts 28 and 98 later, cam operated switch S33 will close to release relays K1 and K2 to deenergize

magnetic clutches

52 and 103 which have been slipping under load for a short duration following the engagement of the locking pawls in the notched cam slots. At the same time, relay K8 is latched to initiate the second phase of the machining cycle. This latched in the relay K1 to energize clutch 103 and a short instant later latched K3 to energize solenoid 57. This reestablishes the rotation of shafts 98, 106 and 156 and holds shafts 54 and 68 in a locked position. Thus the first dwell portion of the cam is being machined. At the same time (when K8 latched), K5 and K6 will latch to respectively start the count of revolutions and degrees of dwell of shaft 156 and also to prepare 40 (FIG. 25) for reverse rotation in respect to shaft 28 at the appropriate time later in the cycle. This preengagement has the effect of bringing gears into mesh prior to actual use and at the same time imposes a slight preload to the train was to render inherent backlash of no concern as regards precision machining accuracy. The predetermining switch 314 keeps a count of the number of degrees of rotation of the rotary table,'-being actuated in one-degree steps by the action of the solenoid 316 and the pawl driven ratchet wheel 320. The switch 314 pulses the solenoid 316 four times for each revolution of shaft 156. a

Just prior to the completion of the last degree of dwell (on the rotary table) 536, will close (its contacts were displaced from each other by a preselected amount consistent with the angle of dwell required) see FIGS. 18 and 19. This latches the relay K7 and releases the relay K8. This then releases K3 causing solenoid 51 to be deenergized, permitting the locking pawl 58 to engage the slot 60 and the notched cam 59 at precisely the'integral 'numberof degrees required for the particular dwell sea 14 to simultaneously cause .the translational cam assembly to return to its initial position and resume rotation of the rotary table. (The rotary table stops for a short instant at the completion of every sequence.) It will be noted that the predetermining device for the already completed first dwell was held inoperable because K5 was not latched due to K7 being latched.

The rise portion of the cam continues until just prior to the completion of the 120th turn of the shaft; At this time, limit switch S3lcloses causing K3 and K4 to release the energized solenoids 57 and shortly thereafter the locking pawls engage the slots in the notched cams to stop the control shafts 54 and 106 at precisely the 120th revolution in the sequence. This stopping is again only for a short instant long enough to permit relays to respond of a revolution later of control shaft cam operated switch S33 will close causing K1 and K2 to release and deenergize

electrical clutches

103 and 52. K8 was latched previously and therefore no change to the system takes place at this time. Upon release of K2'and with limit switch S31 closed, K1 will latch to energize the electrical clutch B1. A short instant later K3 will latch in to energize solenoid L1 and withdraw the locking pawl from the notched cam 59 to initiate the second dwell portion of the cam to be machined. K2 and K4 are prevented from latching by interposing appropriate open relay contacts in their particular circuits. This prevents operation of the translational cam assembly while permitting the movement of the rotary table and so to machine a dwell (the second dwell) on the cam to; be machined.

At the same time, relay K10 will be latched in to energize solenoid LSthe same as solenoid 316 to drive the predetermining ratchet 320 for the second dwell intermittently one degree at a time. it This continues until just prior to the completion of the last preselected degree in' the second dwell. Then S36 contacts will close and immediately release K3 to a deenergized solenoid 57 and subsequently to cause the locking pawl to engage the slot example, a fall, dwell, rise, stop selector station 3 (FIG... U

26) sequence would be identical with the one previously described with the exception that the'operation must be suspended at the end of the rise instead of at the second 26 rotation, cam operated switch S33 will close. This releases K1 to deenergize the magnetic clutch 103. K2

after'Kl has been energized, K3 will latch and K4 will also latch to energize solenoids 57. K6 was latched previously and therefore the reversing mechanism solenoid is. energized. This then being the machining of the rise portion of the cam since the action of the-solenoid is to withdraw the locking pawls from the slots in the notched cams and permit rotation of

shafts

54 and 68 and 106 and 158 dwell." This is accomplished by inserting two sets of relay contacts (K10, normally closed and K1, normally open) in parallel. This has the ellect of stopping the machine operation at the end of the rise portion of the sequential operation. By interposing a set of relay contacts K6, noranally closed and K2, normally open, in parallel, directly in line for fall, rise, stop, selector station 4 (FIG. 26)

and placing this in parallel with a latch type relay K12. This particularcycleis readily obtained. By reference -to the electrical diagram (FIG. 26), other arrangements will be evident as means for accomplishing the various other cycles.

For cams which have a multiple number of rises or falls, or where the radial increment or angular extent of the rise and fall portions are not the same, 360 continuous machining is not possible. For these cases, semiautomatic operation is utilized bystopping the continuous machining operations at the end of a rise or dwell and making the appropriate settings and then resuming the continuous machining operations.

Although not shown on the sequence control knob (FIG. 24) or in the schematic electrical wiring diagram, the following semi-automatic operations are possible in addition to those mentioned above:

A cam blank 152 or 154 to be machined is positioned on the rotary table 148 and clamped in position. The

- correct position of the roller 240 is set.

speed

change gear arms

132 and 134 are set for the desired angle of rise and/ or fall of the work table in order to time a given translational movement of the work table over an arcuate extent on the surface of the cam. The pantograph mechanism is set as previously described to move the work table in timed relationship with rotary table movement for the desired magnification. A cam motion is chosen and the follower 192 is positioned in association with the cam which will give such motion. In those instances where correction for positioning of the follower. on an oscillatable lever arm is required, the In the event that the swing arm compensator is not used, the magnetic clutch 330 will not be energized and therefore no movement of work 250 takes place. Thus, the overhead ram 237 does not move and is therefore clamped by appropriate means (not shown). The hand wheel 218 is used to set a positioning of the pantograph mechanism and a scale thereon may be used to indicate the specific cam rise required for the rotational movement of the table to be effected.

The workis then brought up to the rotating cutter or grinder and the feed is made manually by the hand wheels 10, 14 and 14until the high point of the cam is reached.

The control panel is set for the desired sequence of cam operations to be accomplished. The angular extent of a first, and if necessary, a second dwell is set by the dials as well as the machine speed control. The start button is pressed to initiate the synchronized rotary and linear motion of the fixture assembly.

The apparatus is now capable of milling a continuous complete cam contour without any addition setting other than those initially made.

What is claimed is:

1. A -machine for automatically cutting a cam without first making a master of said cam comprising, a cutting tool, a work table carriage, a rotary work table on said carriage, a control cam, pantograph means connected to at least one of said carriage and said cutting tool and having a portion maintained in engagement with said control cam and movable thereby, means for rotating said work table and-for moving said control cam, and variable timing means connected to said control cam moving means and said table rotating means for variably controlling the rotation of said table in relation to movejment of said control cam'to effect. cutting of rises and 3. A machine for automatically cutting a cam without first making a master of :said cam. comprising, a supporting frame, a rotary work table supporting carriage mounted on said frame for to and fro'movement, a rotary work table on said carriage, a control cam, a panto- -graph connected to said work table carriage and having a portion maintained in engagement with said control cam whereby movement of said cam is effective to move said work table carriage in response to movement of said pan- :tograph, power means for rotating said worktable and for moving said control cam, and variable timing means connected to said power means for variably controlling 'the rotation of said table in relation to movement of said control cam, said timing means including means to a reverse the direction of movement of said control cam.

4. A machine for automatically cutting a cam without first making a master of said cam comprising, a supporting frame, a rotary work table supporting carriage mounted on said frame for lateral to and fro movement, a rotary work table mounted on said carriage, a con-' trol cam mounted on said frame for to and fro movement, a pantograph connected to said work table car- 16 riage, means to bias a portion of said pantograph into engagement with said control cam, power means for rotating said work table and moving said control cam, and variable timing control means connected to said power means and effective to control the rotation of said work table in accordance with movement of said control cam.

5. A machine for automatically cutting a cam according to claim 4, wherein said timing control means includes means for varying the speed of rotation of said work table.

6. A machine for automatically cutting a cam according to claim 5, wherein said timing control means ine cludes means for reversing the direction of movement of said control cam. 7. A machine according to claim 6, wherein said power means includes a driving motor, and said timing control means includes a threaded spindle member, said control cam being carried by a carriage having an internally threaded portion in engagement with said spindle member for movement therealong in response to rotation of said spindle member, and drive means connecting said driving motor with said spindle member.

8. A machine for automatically cutting a cam accord ingto claim 7, wherein said drive means includes means for accurately positioning said threaded spindle prior to rotation thereof.

9. A machine for automatically cutting a cam comprising, a supporting frame, a work table supporting carriage mounted on said frame for to and fro movement thereon, a rotary work table on said carriage, a screw shaft rotatably supported by said frame, a control cam carriage having a threaded portion in engagement with said screw shaft for axial movement therealong in response to rotation thereof, said cam carriage having at least one control cam, a pantograph connected to said work table and having a portion maintaind in engagement with said control cam, driving means connected to said screw shaft and said work table for rotation thereof, and control means for variably regulating the rotation of said work table and the rotation of said screw whereby to regulate the outline being cut on said cam.

10. A machine for automatically cutting a cam according to claim 9 wherein said control means includes means for stopping rotation of said screw shaft and continuing rotation of said table for effecting the cutting of a dwell on said cam.

11. A machine for automatically cutting a cam according to claim 9, wherein said control means includes means for reversing the rotation of said screw shaft to move said cam carriage in an opposite direction.

12. A machine for automatically cutting a cam according to claim 9, wherein said drive means includes a driving motor, an output driving shaft, and means connected between said driving motor and said ouptut driving shaft for accurately positioning said output driving shaft prior to rotation thereof.

13. A cam cutting machine comprising a movable table carriage, a work table rotatably mounted on said carriage, a control cam, cutting tool means, means connected to at least one of said work table carriage and said cutting tool means and having a follower portion maintained in engagement with said control cam and movable thereby upon movement of said control cam, means for independently and variably rotating said work table and for moving said control cam, and timing means connected to said control cam moving means and said table rotating means to move said cutting tool means and said work table relative to each other whereby a workpiece placed on the table is cut by the cutting tool over a prescribed arcuate path by the cutting tool as the .table is rotated in timed relationship to said control cam.

14. A machine for automatically cutting a cam without first making a master of said cam comprising, a cutting tool, a movable work table carriage, a work table rotatably mounted on said carriage, a control cam, pantog raph

Claims

1. A MACHINE FOR AUTOMATICALLY CUTTING A CAM WITHOUT FIRST MAKING A MASTER OF SAID CAM COMPRISING, A CUTTING TOOL, A WORK TABLE CARRIAGE, A ROTARY WORK TABLE ON SAID CARRIAGE, A CONTROL CAM, PANTOGRAPH MEAN CONNECTED TO AT LEAST ONE OF SAID CARRIAGE AND SAID CUTTING TOOL AND HAVING A PORTION MAINTAINED IN ENGAGEMENT WITH SAID CONTROL CAM AND MOVABLE THEREBY, MEANS FOR ROTATING SAID WORK TABLE AND FOR MOVING SAID CONTROL CAM, AND VARIABLE TIMING MEANS CONNECTED TO SAID CONTROL CAM MOVING MEANS AND SAID TABLE ROTATING MEANS FOR VARIABLY CONTROLLING THE ROTATION OF SAID TABLE IN RELATION TO MOVEMENT OF SAID CONTROL CAM TO EFFECT CUTTING OF RISES AND FALLS ON SAID CAM.