US3286593A

US3286593A - Method and apparatus for chamfering toothed machine elements

Info

Publication number: US3286593A
Application number: US418501A
Authority: US
Inventors: William H Bibbens
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-12-15
Filing date: 1964-12-15
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22

Description

Nov. 22, 1966 w. H. BIBBENS 3,286,593

METHOD AND APPARATUS FOR CHAMFERING TOOTHED MACHINE ELEMENTS Filed Dec. 15, 1964 5 Sheets-Sheet l INVENTOR. WILLIAM H. Baaesus Nov.'22, 1966 w. H. B IBBENS 3,286,593

METHOD AND APPARATUS FOR CHAMFERING TOOTHED MACHINE ELEMENTS Filed Dec. 15, 1964 5 Sheets-Sheet 2 INVENTOR. WILLIAM H. BIBBENS Nov. 22, 1966 w. H. BIBBENS METHOD AND APPARATUS FOR CHAMFERING TOOTHED MACHINE ELEMENTS Filed Dec. 15, 1964 5 Sheets-Sheet 3 INVENTOR. WILLIAM H. 6:555:43

a WM NEY- Nov. 22, 1966 w. H. BIBBENS 3,286,593

METHOD AND APPARATUS FOR CHAMFERING TOOTHED MACHINE ELEMENTS 5 Sheets-Sheet 4 Filed Dec. 15, 1964 IgVENTOR.

IBBENS ATT NEY.

Nov. 22, 1966 w. H. BIBBENS 3,

METHOD AND APPARATUS FOR CHAMFERING TOOIHED MACHINE ELEMENTS '5 Sheets$heet 5 Filed Dec. 15, 1 6

INVENTOR. WILLIAM H. BIBBENS ATTO NEY United States Patent 3,286,593 METHOD AND APPARATUS FOR CHAMFERING TOOTHED MACHINE ELEMENTS William H. Bibbens, 1078 Puritan, Birmingham, Mich. Filed Dec. 15, 1964, Ser. No. 418,501 Claims. (Cl. 901.4)

This invention relates to methods and apparatus for chamfering end edges of teeth of various toothed elements such as gears, splines, and the like. The present application is directed particularly to an improved machine of the universal type.

The advantages and often indispensable necessity of chamfering sharp edges of teeth of toothed machine elements, such as gears, splines, and the like have now been well appreciated in the art. In many responsible applications of such machine elements having their sharp edges, particularly at the end face-s thereof, properly chamfered, is considered as indispensable for the proper operation and wear resisting characteristics of such elements, and lack of such ohamfering is considered to be not a proper engineering design for such elements. In other applications of less responsible nature, advantages of having the sharp end edges of the teeth of such elements properly cham'fered are such as to make chamfering at least very desirable.

Accordingly, requirements for chamfering gears and similar machine elements have increased very substantially within the last decade. With it increased the variety of types and sizes of such machine elements, presenting further problems and requirements.

More particularly, because of such increase in the variety of application of chamfer-ing, the necessity of providing a ch-amfering machine of a more universal type than was heretofore available, has been clearly felt for quite a number of years. It can be understood that where the volume of production of a certain gear or a similar element is relatively large, use of a special machine designed and built for operating on that particular gear is usually justified as to its cost. On the other hand, when the volume of production of such a gear or a similar element is relatively small, or where that particular element is manufactured in a number of sizes, the cost of designing and building such a special machine for each type Oll' size becomes prohibitive and makes application of cham'fering and the attainment of the advantages thereof exceedingly .diflicu-lt.

One of the objects of the present invention is to provide an improved machine for chamfering gears, splines,

and the like whereby the above problems and disadvantages are overcome and largely eliminated without introducing other problems, or increasing in any app-reciable manner the costs involved.

Another object of the present invention is to provide an improved gear chamfering machine which can be readily and economically changed to accommodate gears having various diameters, number of teeth, various diamet-ra-l pitches, various types of teeth, such as straight teeth, as in the case of spur gears, or helical and spiral teeth, as well as spline teeth, and the like.

A further object of the present invention is to provide a universal gear chamfering machine which will deburr and ehamfer the teeth of a workpiece, including end edges thereof which are virtually inaccessible, with at least one full tooth end edge profiled with the chamfering operations being performed simultaneously at opposite sides of the workpiece axis, at both end faces of a gear or other toothed workpiece, thus doubling the output of the chamcferi-ng machine just the combination of these particular features alone.

A still further object of the invention is to provide an Patented Nov. 22, 1966 "ice improved gear cham'fering machine of the universal type in which, after the one cham'fered workpiece gear is unloaded manually and a new workpiece gear is loaded, further operations forming the same cycle are performed automatically, with the operator required only to push certain control buttons and upon completion of the cycle to unload the chamifered gear.

A still further object of the present invention is to provide an improved fear chamfering machine in which after proper cutters for the gears to be charnfered have been developed and made, retooling and setting the machine for any specific gear or other similar workpiece can be done in a shop in a matter of a few minutes only.

A still further object of the present invention is to provide a gear chamfer'ing machine of the universal type having improved locating means for the workpiece gear, together with a simple and rapid means of adjustment of the cutter-actuating and cutter-holding means, to establish the proper lateral and vertical position of the cutter paths in [relation to the end edges of the workpiece to be chamfered.

A still further object of the present invention is to provide an improved gear chamfering machine which is safe and dependable in operation and in which novel safety features are provided, whereby the possibility of damage to a workpiece gear or of injury to the operator is reduced to a minimum.

A still further object of the present invention is to provide an improved gear chamfering machine of the foregoing character which is simple and rugged in construction, and which can be operated safely by unskilled persons.

In one of its other aspects, the invention contemplates providing an improved method for cham'fering end edges of gears, splines, and similar toothed elements.

Further objects and advantages of this invention will be apparent from the :following description and appended claims, reference being bad to the accompanying drawings forming a part of this specification, wherein like reference characters designate corresponding parts in the several views.

FIG. 1 is an elevational view illustrating an improved machine embodying the present invention, with the parts of the frame thereof being broken away to expose to view certain vital components thereof.

FIG. 2 is a fragmentary end view taken with the observer presuming to look on the left-hand end of the machine of FIG. 1, and illustrating the gear mechanism wit-h the aid of which the machine can be set to cut a gear with any specific number of teeth within the range of the machine.

FIG. 3 is a tragmentary elevational view of one of the cutter spindle actuating mechanisms mounted to a laterally slideable column or assembly and having provided thereon vertical ways for vertical adjustments of the cutter spindle head assembly. Also shown in said figure is the main drive line means for actuating the cam shafts and other devices producing intermittent motions of the work cycle of the machine.

FIG. 4 is a sectional view taken in the direction of the arrows on the section plane passing through line 4-4 of FIG. 3.

FIG. 5 is a fragmentary sectional view taken in the direction of the arrows on the section plane passing through the line 5-5 of FIG. 4.

FIG. 6 is a sectional view taken in the direction of the arrows on the section plane passing through the line 66 of FIG. 1, and illustrating the angular locating device for the workpiece gear.

FIG. 7 is a fragmentary sectional view taken in the direction of the arrows on the section plane passing through the line 7-7 of FIG. 1, and illustrating the indexing device changing the continuous movement of the main drive shaft into intermittent movement required for indexing the workpiece-holding spindle.

FIG. 8 is a fragmentary elevational view illustrating the application of the opposing cutters to the workpiece gear at both end faces thereof, and on the opposite sides of its axis.

FIG. 9 is a fragmentary plan view illustrating application of one cutter to a workpiece gear having an even number of teeth.

FIG. 10 is a view similar in part to FIG. 9, illustrating the space relation of the cutters to a workpiece gear having odd number of teeth.

FIG. 11 is a diagrammatic view illustrating the movement of one point of the cutter in the process of one cycle, i.e. during the cutting, relief, return, and reposition strokes of the cutter.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways within the scope of the claims. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

It will be understood that the term gear as used in the following description and claims is intended to cover also other toothed elements, such as splines, and the like.

Referring specifically to the drawings, the machine illustrated therein comprises generally a workpiece spindle, generally designated by the numeral 15, adapted to receive a workpiece gear 16, to locate the same in a predetermined position, and to index said .gear at least one tooth at a time. A laterally slideable column assembly 17, mounted on the machine frame 18, carries an upper cutter head 19 operating the upper cutter 20, while a slideable column assembly 21 carries a lower cutter head 22 operating the lower cutter 23. There are provided horizontal and vertical positioning blocks used to establish positions of the

sliding assemblies

17 and 21 and, therefore, of the pivotal axes of the cutters and 23 carried thereby with relation to the workpiece gear teeth during the cutting cycle. Such positioning blocks for the sliding assembly 17 are shown in FIGURE 3, wherein the horizontal positioning block is designated by the numeral 24 and the vertical positioning block by the numeral 29. Driving means for said cutters are provided to operate said

cutters

20 and 23 to produce simultaneous cutting strokes thereof, while the spindle 15 remains stationary, and to rotate said spindle 15 one tooth of the workpiece gear '16 at a time, as the cutters are returned and repositioned to their start cutting positions. Various adjustments for proper cutting of the workpiece gear 16 and for the

cutters

20 and 23, as well as other service devices determining the desired cycle of the machine are provided and are described in detail below.

The general concept of application of chamfering form cutters to the end edges of the workpiece gear teeth to be chamfered, is based on the disclosure of the U.S. Patent No. 2,668,480 to John M. Christman, as well as of the U.S. Patent No. 2,865,257 to John M. Christman and William H. Bibbens. The present application covers a further development of said concept disclosed herein and its application to chamfering workpiece gears simultaneously at both end faces thereof.

As illustrated in FIG. 9, the form cutter such as illustrated at 30, is, in effect, a combination of two cutter teeth operating on two separate spaced gear teeth and cutting simultaneously at least two near side edges of such spaced teeth, such as edges of the

teeth

31 and 32, which are separated by at least one full tooth, such as 33. The construction of the form cutters, such as cutter 30, and

development of their cutting edges, is disclosed in detail in the above-mentioned patents. It may be mentioned here, however, that cutting edges of the form cutters may be developed to cut, in addition to the near side edges, also portions of at least halves of the top edges, such as 34, and of root edges, such as 35. In the present embodiment of the invention, with the top edge 34 being already chamfered in the process of turning the blank of the workpiece gear, only a portion of the root edge is cut by the cutter 30, as indicated at 36.

It will be understood now that in the embodiment illustrated, the form cutter 30 cuts in one cutting stroke two side edges and two halves of root edges, which condition, considering that the top edge is already chamfered, gives in aggregate full chamfering of one complete tooth in one cutting stroke. Thus, if the workpiece gear is indexed the number of times equal to the number of its teeth, all of said teeth will be fully chamfered after being so indexed.

In accordance with the invention, a substantially identical form cutter, such as 40, is provided in a substantially similar position on the other end face of the workpiece gear 16 diametrically opposite to the form cutter 30, Le. on the other side of the axis of the workpiece gear 16. The similarity of positions of the

cutters

30 and 40 are such that if, for example, we turn the cutter and the gear over degrees around a center line 41, perpendicular through the center line 42, the cutter 30 and the

teeth

31, 32, and 33 thereof would assume the exact position of the cutter 40 and corresponding gear teeth previously disposed at the opposite end face of the workpiece gear 16. Referring to the elevational or front views of the drawings, such as FIGS. 1 and 8, wherein the exterior outline of the workpiece gear 16 appears as a rectangle, the illustrated arrangement of the cutters may be termed as providing for chamfering gear teeth ends at diagonally opposite gear ends, with the cutting strokes of the cutters being directed toward the axis of the workpiece gear.

With an even number of teeth, such as shown in FIG. 9, there generally will be a tooth disposed along the center line 42 on the other side of the workpiece gear 16. However, if the workpiece gear, such as 44, has an odd number of teeth, there will be a space at the other end of the center line, such as 42, while the adjacent tooth on either side of such center line will be offset from said center line 42 for one-half of the tooth pitch. In order to attain proper results, the chamfering cutters, such as 40 and 30, are equally offset toward one common side for the predetermined distance equal to at least onequarter of the diametral pitch, as illustrated in FIG. 10.

In other words, the

cutters

40 and 30 will be offset with relation to the axis of the gear for a distance as indicated at c of FIG. 10, with b-b indicating location of the center line of the cutters.

The selection of the angle of chamfer, and therefore the angle at which the cutter is applied to the gear teeth, is also disclosed in detail in the above-mentioned patents.

As can be seen from an examination of FIG. 8, the upper cutter 20 and the lower cutter 23 move along an arcuate path determined by the distance from the cutting edges to the center of the cutter spindle shafts, such as the distance indicated in FIG. 11 by the numeral 46.

It will be understood at this point that in order to relieve the cutting edge on its return stroke and eliminate its rubbing against the cut chamfer, the center of the cutter head spindle or shaft is made moveable by the provision of the eccentric sleeve, such as one illustrated at 48 in FIGS. 3 and 4 and actuated independently of the shaft 49. The cutting movement of the cutter, such as 20, is produced by the reciprocal rotation of the shaft 49 with the position of the sleeve 48 being as illustrated in FIGS. 3 and 4. In such a condition, the center of the cutter rotation is in the lower position as indicated at 47 in FIG. 11. Upon completion of the cutting stroke, as illustrated by the line 50 in FIG. 11, the sleeve 48 is reciprocally actuated to raise said shaft, and therefore the center of its rotation, to the point 51, whereupon the return stroke of the cutter proceeds along the line 52 in order to clear the chamfer on the return stroke of the cutter.

In order to provide uniform chamfering for varying conditions of geometric forms of end edges of gear teeth, adjustable means are provided for varying the location of the arcuate paths of the form cutters, such as shown at 20 and 23. In the present embodiment such means are exemplified by the tapered end 55 of the shaft 49, with the measurements of the degree of adjustment appearing on the dial, such as 56. The indicator knob 57 having a reference mark 58 is secured to the tapered end 55 of the shaft 49, as illustrated in FIG. 5. For more secure orientation, the adjustment is made in small increments determined by the external serrations 54 provided on the shaft 49 and cooperating with complementary serrations 59 provided in the main toolholder 60. Anchor screw 61 is used to secure the adjusted toolholder assembly at its respective selected position.

The workpiece spindle is adapted to receive the workpiece gear 16. A locating stop 66 positions the workpiece for vertical location. Centering location is determined by means of the centering expanding type locator 64. After the workpiece gear 16 is centered in the spindle 15 and bears with its lower face on the end locator 66, said gear is thus thereupon located angularly and locked or chucked in this position in order that the cutters and 23 may chamfer the selected profile of the end edges of the gear teeth in the proper manner.

The angular locating device is exemplified in the present embodiment by a swinging arm device generally designated by the numeral 70. The device 70 includes an elongated articulated arm 71, having one of its ends clamped at a predetermined and adjustable height on the cylindrical bar or pivotal shaft 72. The free end of the arm 71 carries a locating finger 74 having a ball end 75 adapted to enter the space between two adjacent teeth of the workpiece gear 16, and thus to locate the same angularly with respect to the

cutters

20 and 23, see FIG. 6. The length of the arm 71 is adjustable by sliding its end 76 in the bracket 78 and securing it in the adjusted position with the aid of screws 79. Adjustment of the distance between centers of 72 and 74 provides for the proper angular positioning of the gear teeth in relation to the workpiece axis and the

cutters

20 and 23 when the dieffrent workpiece gears have different diameters and diametral pitches. Adjustment of the height of the swinging arm 71 on the pivotal shaft 72, mentioned above, provides for adjusting said arm at predetermined height as may be required by the nature of the workpiece gear. Such adjustment is effected by loosening the screw of the split bracket 78 embracing the pivotal shaft 72 journaled in the assembly 21 as shown, moving the brackets 78 to any desired height on the pivotal shaft 72, and tightening said screw.

The arm 71 is swingable into its workpiece locating position, such as shown in FIG. 6, thus providing for chucking said workpiece 16 and then away from the workpiece 16, i.e. into its retracted position, such as indicated in phantom lines in FIG. 6. Clearing the workpiece 16 sets up the electrical circuit for the work cycle.

Various electrical control buttons are assembled on the

panels

80 and 81. These buttons control electric circuits energizing an electric motor 85 providing mechanical drives for the described mechanisms, energizing various valve controlling solenoids and an electric motor driving a hydraulic pump which operates hydraulic cylinders, such as cylinders 82. Operation of the hydraulic cylinders 82 moves the cutter head assemblies advancing the cutter heads into their operative positions. The hydraulic cylinder 84 operates the means locking and unlocking the workpiece gear in the spindle 15. Both manual and automatic circuitry is provided by selector controls for manual set up cycling and automatic cycling.

The main drive motor 85 is mounted at the bottom of the machine and it drives with the aid of a belt 86 a spline shaft 87. The shaft 87 is provided with an electrically controlled clutch 88 and an electrically controlled brake 89. Worm-and-gear mechanism 91 drivingly connects the shaft 87 with the lower cutter head 22, while the drive 92 connects said shaft with the upper cutter head 19. Describing only one such driving connection in detail, the worm-and-gear mechanism 92, connects said main drive shaft 87 with a vertical spline shaft 93, see FIGS. 3 and 4, operating through a set of beveled gears 94 and 95, see 'FIG. 4, earns 96 and 97. The cam 96 operates a crank 98 secured to the cutter shaft 49 and imparts to it a swinging motion to produce the cutting and the return strokes of the cutter. The cam 97 operates a crank 99 secured to the eccentric sleeve 48, adapted to raise the shaft 49 after the cutting stroke is completed, in order to cause the return stroke of the cutter to proceed along the line 52, as illustrated in FIG. 11.

The construction of the drive for the lower cutter head 22 is substantially similar to that of the upper cutter head 19, described above, and such description need not be repeated.

It will be noted, however, that in both of these constructions, the continuous rotary motion of the spline shaft 87 is converted into a reciprocating rotation of the shaft 49 by the cam-and-crank mechanisms described above with reference to the upper cutter head 19.

Intermittent or indexing movements of the spindle 15 is imparted to said spindle from the continuously rotating main drive shaft 87. The continuous rotation of the shaft 87 is converted into intermittent rotative movement of the first auxiliary shaft 100 by the indexing drive mechanism illustrated in detail in FIG. 7. Said device includes a cylindrical cam 101 mounted on a shaft 104 and connected to the shaft 87 through a worm-and-gear mechanism 105. A circular plate 102 mounted on the shaft 104 carries a plurality of followers 103 running in slots, such as 106, provided on said cylindrical cam 101. The followers 103 operate to rotate the plate 102 when the respective follower is in the curved portion 1060 of the slot, and to keep the plate 102 stationary when the respective follower is in the straight portion 106s of the cam.

On the end of the first auxiliary shaft 100 there is mounted a time gear 110 connected with the aid of an idler pinion 111 with a change pinion 112. The pinion 112 is interchangeable and may be substituted by pinions having different number of teeth. The

slots

113 and 114 provided on the mounting brackets of the gears, in a manner well known in the art, are provided for adjustment of the gears in the process of substitution of the change gear 112 because of different diameters thereof. The second auxiliarly shaft 115, on which the change pinion 112 is mounted, extends parallel to the first auxiliary shaft 110 with its opposite end being connected, with the aid of a worm-and-gear mechanism 120, with the spindle 15 to rotate the same intermittently.

The purpose of the provision of the timing gear mechanism, including the

gears

110 and 112, is to impart to the spindle, with each step of its rotation, such angular movement as to index the workpiece gear through one pitch distance. This distance varies in different workpiece gears, depending on their respective diameters and the number of teeth. By a proper selection of the change pinion 112, such distance, computed in advance and translated into its corresponding angular value, may thus be properly produced.

An electric counter, generally designated by the numeral 121, see FIG. 1, is provided in order to set the machine for a definite number of step movements corresponding to the number of teeth in the workpiece gear. By operation of this device, when the operator presses the corresponding control button, the machine will start and index through a number of steps equal to the number of teeth, with the cutters going through equal number of chamfering and return strokes, and will stop with the cutters being in their outward position and out of contact with the gear. Stopping of the machine is effected by the electrically controlled clutch 88 and brake S9. Thereupon the cutter head carrying assemblies will move by the operation of the hydraulic cylinder 82 away from the workpiece gear and will stop in their retracted positions.

Setting the machine for a definite workpiece gear, after the cutters therefor have been developed, is exceedingly simple and may be accomplished in only a few minutes.

The change pinion 112, of a predetermined number of teeth, is first put in place, and the electric counting device, such as 121, is set for the number of teeth equal to that of the workpiece gear. The workpiece gear is then placed in position in the spindle 15, and located therein along the axis of the spindle, to bring the workpiece gear to a proper height with respect to the

cutters

20 and 23. Substantial adjustments of the cutters with respect to the workpiece gear are attainable by moving the cutter heads in the vertical slides such as 122 of the assembly 17. Moving the cutter head up or down is attained by using the screw-operating handle 123 for the head 19, and handle 124 for the head 22. The angular locating device is moved to locate the gear angularly, as described above, in a preliminary manner. Thereupon the cutters are adjusted laterally in dovetail adjusting Slides and secured in their adjusted position by screws, such as 125. After preliminary adjustments, the above parts may be readjusted in a more percise manner to produce chamfer of proper depth. Actual experience indicates that such adjustments can be easily made by a work-man having only average skills.

Operation of the machine includes merely loading the workpiece gear into place, pressing the prescribed control buttons and unloading the chamfered gear, and such operation can be successfully carried on by a workman having only average skills of a production worker, or even by unskilled workmen. When the machine stops, the cutter heads and the cutter stop in their retracted positions, which is a feature of serious importance, for many reasons. Thereupon the workman merely presses the button unlocking the workpiece gear and removes it from the machine. Thereupon he loads the new workpiece gear, locates it angularly -by moving the angular locator to the position of contact with the gear, as described, presses the button locking the gear in the spindle, and swingsthe angular locator into its retracted position. Thereupon he presses the button actuating the driving means, for which operation the use of both hands is required for the purposes of safety.

An additional feature of safety is found in the provision of the circuit breaker switch, such as 126, see FIG. 6, operated by the angular locating device. As shown in FIG. 6, when the locating finger 74 is in contact with the gear, the switch button 127 is pressed in by the high spot 128 of the cam provided on the bracket 78 of the anguler locator device, causing the circuit energizing the driving motor 85 to be disconnected, and electric starting buttons ineffective to start the motor. It is not until the arm 71 is moved by the operator into the position illustrated in FIG. 6 in phantom lines, that the interrupter switch closes, whereupon pressing two additional electric control buttons will start the motor.

By virtue of such a construction, the possibilities of damage to the workpiece gear or injury to the operator are reduced to minimum.

' ter, indicated in phantom lines in FIG. 1 and designated therein by the numeral 130, may be provided on an attachable arm, such as 131, to have such center disposed co-axially with the spindle 15. Such supporting center '8 device is removed when the workpiece gear is in the form such as workpiece gear 16, illustrated herein.

By virtue of the above disclosed method and machine, the objects of the present invention listed above and numerous additional advantages are attained.

I claim:

1. In a machine for chamfering end edges of teeth of a workpiece gear, said machine comprising a spindle adapted to receive the workpiece gear leaving it teeth exposed for chamfering at both of its end faces and to locate said gear axially, a locating member adapted to engage at least one tooth of the workpiece gear when moved in a position of contact therewith and to locate said workpiece gear on said spindle angularly, means to lock the workpiece gear on the spindle in the located position, means to move said locating member out of contact with the gear, two swinging cutters disposed one at each of the two end faces of the workpiece gear in similar space relation to the respective faces of the workpiece gear, each of said cutters adapted to chamfer two near side edges and at least a portion of each of the adjacent respective root edges of two spaced teeth separated by at least one full tooth, cam-and-follower means, one for each of said cutters adapted to actuate the same through similar reciprocating paths to produce successive chamfering and return strokes, and means to index the spindle one tooth at a time until completion of chamfering of all teeth on both end faces of the workpiece gear.

2. In a machine for chamfering end edges of teeth of a workpiece gear, said machine comprising a spindle adapted to receive the workpiece gear for operation of chamfering cutters at both of its end faces, stop means on said spindle adapted to locate the workpiece gear at a predetermined position along the axis of the spindle, an angular locating device to locate the workpiece gear angularly for proper registry of the teeth thereof with the chamfering cutters, said device comprising an articulated arm having one of its ends pivoted and its free end carrying a locating finger adapted to enter the space between two teeth of the workpiece gear and to engage said teeth for locating the workpiece gear angularly in a positive manner, two swinging cutters disposed one at each of the two end faces of the workpiece gear in similar space relation to the respective faces of the workpiece gear, with each of said cutters adapted to chamfer two near side edges and at least a portion of each of the adjacent respective root edges of two spaced teeth separated by at least one full tooth, means to actuate said cutters through similar reciprocating paths to produce successive chamfering and return strokes of said cutters, electric driving means for said cutter actuating means, and a switch operated by said angular locating device and adapted to render the cutter-actuating means inoperative until the locating finger thereof is moved out of contact with the workpiece gear and the arm thereof is moved into a retracted position of non-interference with loading and unloading of the workpiece gear on said spindle.

3. The machine defined in claim 2, with the arm of the angular locating device being adjustable as to its length to accommodate work gears of various dimensional specifications.

4. In a machine for chamfering end edges of teeth of a workpiece gear, said machine comprising a rotatable spindle adapted to receive a workpiece gear and to hold it by its middle portion but leaving its teeth at both of its end faces exposed to the action of chamfering cutters, stop means to locate the workpiece gear on said spindle a predetermined position along the axis thereof, a locating finger means for locating the workpiece gear angularly, hydraulically actuating locking means to lock the workpiece to said spindle for rotation therewith, two slidable assemblies movable in and out of the respective operation positions at said spindle, adjustable stop means for each of said assemblies at the operation position, a cutter head carried by each of said assemblies, each of said head carrying an oscill-atable shaft, a swinging cutter mounted on said shaft and adapted, when the respective assembly is in operation position, to chamfer two near side edges and at least a portion of the adjacent respective root edges of two spaced teeth of the workpiece gear separated by at least one full tooth, a continuously driven auxiliary shaft, a cam-and-follow means transferring continuous rotation of said auxiliary shaft into oscillation movements of said oscillatable shaft to move its respective cutter and thus to produce a cutting stroke and a return stroke thereof, an eccentric sleeve operatively interposed between said oscillatable shaft and the follower of the cam-and-follower means to raise the cutter on its return stroke.

5. The machine defined in claim 4 and including angularly adjustable means between said oscillatable shaft and the cutter.

6. The machine defined in claim 4, with each cutter head including slide-and-screw means adapted to move said head bodily along the axis of the spindle for adjustments, and locking means for locking the head in its adjusted position.

7. The machine defined in claim 4, and including electric switch-and-cam means to start the chamfering cycle after the workpiece gear is located and locked in the spindle, and the angular locating finger is withdrawn from contact with the workpiece gear, to carry the cycle until completion of chamfering of all of the teeth of the workpiece gear, and to stop the cutters in their return position.

8. In a machine for chamfering end edges of teeth of a workpiece gear, said machine comprising a spindle adapted to receive a workpiece gear leaving its teeth exposed at both of its end faces to the action of chamfering cutters and to locate the workpiece gear axially, a locating tapered finger adapted to be moved between two adjacent teeth of the workpiece gear to locate the same angularly and thereupon to be moved out therefrom, means to lock the workpiece gear on said spindle for rotation therewith, two swinging cutters adapted to operate simultaneously at both end faces of the workpiece gear to chamfer the teeth thereof, driving means for said cutters, said driving means comprising a continuously rotating main drive shaft, first intermediate shaft, a cam-and-follower means adapted to convert the continuous movement of said main drive shaft into intermittent movement of said first intermediate shaft, a second intermediate shaft arranged parallel to the first intermediate shaft, an interchangeable gear train connecting said intermediate shafts and providing for selectively changing the angular velocity of the second intermediate shaft, and a worm-and-gear mechanism connecting the workpiece gear receiving spindle with said second intermediate shaft to rotate said spindle intermittently to index the workpiece gear in time relation to the movements of the chamfering cutters.

9. In a machine for chamfering end edges of teeth of a workpiece gear, said machine comprising a rotatable articulated work spindle adapted to receive a workpiece gear and to hold it in a predetermined position along the axis of said spindle leaving its teeth at both of its end faces exposed in predetermined respective positions to the cutting path of chamfering cutters, stop means to locate the workpiece on said spindle in said predetermined position, an adjustable locating finger means for locating the workpiece gear angularly, with guide means providing for predetermined settings of said locating finger means both parallel and at right angle to the axis of said spindle, locking means to lock the workpiece gear to said work spindle for rotation therewith, two assemblies movable in and out of the respective operation positions at said spindle, each of said assemblies carrying a swinging cutter, one cutter to operate at one face end of the workpiece gear and the other to operate at the diagonally opposite face end thereof, adjustable stop means for said assemblies to locate the same and the cutters carried thereby in space relation to the workpiece gear both with respect to its position along the axis of said spindle as well as with respect to the distance from said axis as determined by the end edge of the workpiece gear tooth to be chamfered.

10. The machine defined in claim 9 and including interlocking circuitry to make operable the means to hold the workpiece in proper relationship to the predetermined path of the cutters passing through a predetermined cutting arc, said interlocking circuitry adapted to keep the machine in non-starting condition until the locating finger means has been retracted from said workpiece and putting the machine into starting condition after the retraction of said locating finger means, all in combination with the means for adjusting the locating finger means in relation to the axis of the workpiece.

References Cited by the Examiner UNITED STATES PATENTS 2,150,313 3/1939 Bauer 1 2,668,480 2/1954 Christman 90-1.4 2,950,654 8/1960 Straw 90-l.4

WILLIAM W. DYER, JR., Primary Examiner.

G. A. DOST, Assistant Examiner.