US3011410A - Method and apparatus for loading internal gears - Google Patents

Description

Dec. 5, 1961 T. s. GATES ETAL 3,011,410

METHOD AND APPARATUS FOR LOADING INTERNAL GEARS Filed Oct. 51, 1955 4 Sheets-Sheet 1 A? a 2, 4 l. 91'

W, I 4W f J 0 I ii I hv INVENTORS THOMAS S. GATES. ALMARON AE TZLER.

BYMmffya WTHSRNEYS Dec. 5, 1961 T. s. GATES ETAL METHOD AND APPARATUS FOR LOADING INTERNAL GEARS Filed Oct. 31, 1955 4 Sheets-She I I /3 J 26 m A A Pi Z7 33 l NVENTOR. -32 THO/{4A8 s. GATES.

AL MARON KETZLE/il BY 5 k 1 ATTORNEYS METHOD AND APPARATUS FOR LOADING INTERNAL GEARS Filed Oct. 51, 1955 Dec. 5, 1961 T. s. GATES ETAL 4 Sheets-Sheet 5 IN VENTOR. THOMAS 3. GA TES. ALMARON KETZL whim ' ATTORNEYS Dec. 5, 1961 T. s. GATES ETAL 4 Sheets-Sheet 4 Filed Oct. 51, 1955 INVENTDR. THOMAS S. GATES. BYWARON KETZLER.

ATTORNEYS United States Patent Cfiice 3,011,410 Patented Dec. 5, 1961 METHGI) AND APPARATUS FOR LOADING INTERNAL GEARS Thomas S. Gates, Grosse Pointe Woods, and Almaron H.

Ketzicr, Grosse Pointe Farms, Mich, assignors to National Breach & Machine Company, Detroit, Mich., a corporation of Michigan FiledOct. 31, 1955, Ser. No. 543,763 8 Claims. (Cl. 90-1) The present inventionrelates to an improved method and apparatus for loading internal gears on a gear shaving machine, the apparatus being entirely automatic in its operation. The invention further contemplates, as an important feature, a novel control of the engagement of a cutting or finishing tool with a formed internal gear blank to be finished, whereby the tool and workpiece will unfailingly be in proper meshing relation at the time of initiation of actual cutting or finishing by the tool. In general, the invention provides a novel and improved sequence of operations, and a novel and improved combination of mechanisms to perform them, by which an internal gear blank is loaded on a rotary finishing machine, finished and unloaded in an entirely automatic fashion, from beginning to end.

Consistent improvements in rotary gear shaving machines during recent years have greatly increased the efficiency and productivity of such machines, in respect to output rate, to the extent that their production is now restricted below optimum capacity by the capacity of available means, manual, semi-automatic or fully automatic, to load the gears into the machine and remove the finished product. In the case of a machine for shaving internal gears, the handling procedures involve the presentation of the gear to be finished in'axial alignment With a holding member or chuck, the axial displacement of the gear into such chuck, the rigid clamping of the gear therein and, following the machining phase, a reversal of these operations to discharge the shaved gear.

If performed manually, this handling procedure would require an amount of time approximating that of the actual shaving operation, and it is evident that automatic provisions which will materially reduce such a time expenditure are highly desirable, indeed. 7

It is therefore a general object of the invention to provide an improved method and apparatus for loading internal gears to a gear shaving machine in an entirely automatic fashion and in the most expeditious and efficient way, to the end that the production rate of the shaving machine shall be correspondingly improved.

More specifically, it is an object of the invention to provide apparatus-which Will advance and align an internal gear to be shaved with a rotatable, positively driven holding chuck, which will shift the gear axially from the advancing means into the chuck directly following the presentation of the gear at the latter, and which will positively clamp the gear in the chuck for the ensuing shaving cycle.

In accordance with the invention, the provisions for advancing and presenting a gear at the rotatable holding chuck may take alternative forms, having in commonthe feature of inclined gravity ways or chutes for the in-feed and out-feed of rough and finished gears, respectively. A leading gear is taken from the in-feed chute by a pneumatically powered reciprocatory transfer unit, which advances the gear into axial alignment with the chuck, and also, in accordance with one embodiment, receives and returns a finished gear to the vicinity of the discharge way or chute after the shaving operation. In each adaptation of the invention, the gear to be shaved is displaced from the transfer unit into the machine chuck by a pneumatically powered ram, which swings into and out of axial alignment with the chuck for this purpose.

The rotatable chuck of the apparatus has associated therewith a plurality of angularly movable clamps and a plurality of axially movable stripper rods; these respective members are actuable to clamp a gear in the chuck following the operation of the loading ram, referred to above, and to eject the finished gear from the chuckafter the shaving cycle. Individual pneumatic plungers are employed to actuate the respective sets of clamping and ejecting members, the plungers being received in pneumatic cylinders which are pressurized in predeterminedly timed relation; and provision is made in the operating connections between the respective angularly shiftable clamping members and the axially shiftable ejecting plungers to permit their necessary rotation with the chuck with which they are associated without imposing any significant rotative torque on the plungers which power the same.

In accordance with one embodiment of the invention,

the finished gears are ejected axially from the chuck directly into a gravity discharge chute or way, along which they proceed to a suitable receiver. In accordance with an alternative form, the ejector pins shift the finished gear into the transfer unit or head which initially presented it to the chuck, and the transfer unit returns the finished gear to a discharge way or chute adjoining the feed-in way or chute; In this position, a special transfer plunger operates to ejecct the finished gear from the transfer unit referred to into the discharge chute, at the same time loading the transfer unit with another gear to be shaved from the feed-in chute.

Considering the structure of the rotary work holding chuck more specifically, the invention provides a chuck which has associated therewith a plurality of radially swingable clamp arms spaced from one another about the periphery of the chuck, which is internally recessed in a proper size to snugly receive the internal gear to be shaved. Each clamp arm is mounted on an elongated rod which has camming engagement with the chuck proper, whereby axial movement of the clamp arm rod will occasion an angular swing of the arm inwardly over an exposed outer face of the gear. This set of clamp arm rods is operatively mounted to the rear'of the chuck on a recipro'catory head, and this head is controlled in its actuating movements, to effect the cam operation referred to, by a pneumatic cylinder.

The chuck is also provided with a plurality of circumferentially spaced ejector pins, which extend axially through recesses or bores in the chuck to accommodate the same. Axial shifting of the pins toward the open mouth of the chuck causes them to engage and eject the gear carried in the latter, which has been-previously un clamped by operation of the cam provisions mentioned in the preceding paragraph. The pins are connected at their rear to a suitable operating head which has an axially fixed but rotatively loose conection on a control plunger, by which the pins are given their axial movement. The plunger in question connects rearwardly to a pneumatic piston whereby operation of the ejector unit is controlled in timed relation to operation of the gear clamp arms. The loose connection prevents rotation of the plunger and piston, yet enables the ejector pins to rotate with the chuck in which they slide axially.

As indicated by the foregoing, it is an object of the invention to provide an improved gear shaving method, featuring the sequence of advancement of individual gears into axial alignment with a work holder or chuck, displacement of the gear into the chuck, clamping of the gear, followed by shaving of the gear, unclamping and ejection of the gear and discharge of the finished gear, either bygravity or by a positive mechanical transference.

As an important feature of this method, as well as the combined apparatus for performing it, the shaving machine incorporates provision whereby the engagement of its cutter with the gear to be shaved is effected after an initial rapid stroke, then a slower advance which actually contacts the cutter with the gear. This advance is accomplished under pneumatic or hydraulic pressure, in a yieldable fashion in accordance with the invention, and if a proper meshing relation of the cutter and gear does not result, the advancing stroke is interrupted until there is a proper mesh. It is contemplated that the cutter be given a jogging push under yielding force at the end of its slow advance, i.e., be imparted slight momentary pulsatory pressure increments while yet in engagement with the end of the gear, whereby it a mesh with the gear teeth does not occur at once, it will take place momentarily thereafter. This is done by a pressure by-pass unit which limits the end pressure on the cutter. It is also within the contemplation of the invention to provide means, for example in a further refinement of a pressure controlled device which affords the pulsatory effect described above, to reverse the movement of the cutter in the event it fails to mesh properly with the gear, causing the cutter to back off for a second stroke or further repeated strokes towards the work.

With these and other objects in view, the invention resides in the novel features of construction and combinations and arrangements of parts as more fully hereinafter set forth.

In the drawings:

FIGURE 1 is a face view of an internal gear shaving machine incorporating the improved apparatus for loading gears according to one embodiment of the invention;

FIGURE 2 is a view generally in side elevation, but partially in section along line 2-2 of FIGURE 3, of the machine of FIGURE 1;

FIGURE 3 is a top plan view of the equipment;

FIGURE 4 is an end view of a generally similar internal gear shaving machine incorporating loading apparatus in accordance with a modification of the invention;

FIGURE 5 is a top plan view of the machine of FIGURE 4;

FIGURE 6 is a fragmentary view in axial section through a work holding chuck and associated gear clamping and ejector means of the apparatus;

FIGURE 7 is a fragmentary view in end elevation of the chuck structure of FIGURE 6, viewed from the right of that figure; and

FIGURE 8 is a fragmentary diagrammatic view illustrating a proposed pressure bypass valve unit for the control of the cutter of the gear finishing machine in its advance into mesh with a gear blank held in the chuck of the apparatus.

Referring first to FIGURES 1, 2 and 3 of the drawings, they depict general structural components of a machine for shaving internal gears, generally designated 10, with which the improved loading apparatus 11 of the invention is associated. This machine operates on the crossed axis principle, although a coaxial relationship of its work holder and cutting tool is shown in the drawings for the sake of simplicity. Much of the equipment appearing in FIGURES 1, 2 and 3 is entirely conventional, including a frame 12; a slide assembly 13, carrying a cutter head 14 and its associated spindle 15 and cutter 16; and a work support 17 in opposed relation to the cutter head. In accordance with the invention, axially aligned inner and outer pneumatic cylinders 18, 19, respectively, are fixedly associated with the work support 17 to project outwardly thereof, in axial alignment with a rotatable chuck or work supporting head 20 of the work support 17. A pneumatic cutter slide cylinder 21. controls movements of cutter head 14 toward and from chuck 20.

The chuck 20 is powered through a gear connection, hereinafter referred to, from an electric motor 22 mounted on the machine frame, and the actual machining operation to shave internal gears is a conventional one.

The reference numeral 23 denotes a pivotally and axially movable ram which is carried on a plunger 24 piloted in a tubular casting 25 atop the work support 17. The ram includes an axial pushing head 26 carried by a rigid radial arm 27 on the outer end of plunger 24. At its opposite extremity, the plunger 24, or suitable piston thereon (not shown), is received in a pneumatic cylinder 28 attached to the mounting casting 25. Alternate actuation of the plunger in opposite directions obviously occasions corresponding axial movements of pushing head 26. A further pneumatic cylinder 29 is mounted to casting 25 to extend laterally therefrom. Cylinder 29 similarly receives a piston or plunger which is appropriately connected operatively, as by rack and segment elements, for example, with the plunger 24. Accordingly, reverse movements of the plunger in cylinder 29 occasion oscillating movement of pushing head 26 about its plunger 24 as an aXis through a predetermined limited angular swing. As illustrated in FIGURE 1, this swing is of sufiicient extent to bring the pushing head 26 into and out of axial alignment with the work recess or chuck 2% Internal gears G to be shaved are gravitationally supplied in sequence by an inclined way or chute 30 which, as illustrated in FIGURE 1, lies in a plane paralleling and slightly forwardly of the outer face of chuck 29. Gears G are discharged from chute 30, under the control of a suitably actuated, periodically acting escapement or metering element 30' associated with chute 3t into an arcuate transfer cradle 31 which is reciprocably carried by a supporting frame, including pneumatic plungers 32 received in a pneumatic control head or housing 33. Appropriate provision is made therein to reverse the direction of movement of transfer cradle 31 in timed relation to the operation of other components of the machine, which are also controlled automatically by appropriate pneumatic valving provisions which will suggest themselves to those skilled in the art.

As received in cradle 31, a gear G to be shaved is in the horizontal plane of the axis of chuck 26*, so that movement of the cradle to the right, as viewed in FIGURE 1, will transport and present the gear G in axial alignment with the chuck. I'I'he pushing head 26 has been swung downwardly prior to this time in axial alignment with the gear, under the control of the ram up-down cylinder 29, whereupon axial movement of head 26 under the control of ram in-out cylinder 28, will shift gear G from cradle 31 into the chuck 29, where it is positively clamped in place by the provisions later to be described.

The reference numeral 35 generally designates a gravity discharge chute, the inner receiving end 3 6 of which is disposed immediately beneath the mouth of chuck Zll in a vertical plane which includes the line of movement of transfer cradle 31. After discharge from chuck 29 by the provisions to be described, the finished gears descend into chute 35 and roll therefrom to a disposal point or collector.

A second adaptation of the invention, in regard to the general provisions for supplying gears G to be shaved and for removing the shaved gears, is illustrated in FIGURES 4 and 5 of the drawings. In this form the receiving end of the discharge chute by which finished gears are removed is located to a side of the chuck 20, in side by side relation to a feed-in chute for gear blanks. Components of the equipment of FIGURES 4 and 5 which have structural features or functions in common with the features or functions of components depicted in FIGURES 1, 2 and 3 are designated by corresponding reference numerals and, in the interest of simplicity and brevity, will not be further described. It may be noted that in the form of FIGURES 4 and 5 the cylinder 29 which controls oscillation of ram 23 is vertical.

The gear feed and discharge unit of FIGURES 4 and 5 is generally designated 37. It includes a feed-in way or chute 38 similar to the chute 30 of FIGURES 1, 2 and 3, the inner end of the chute 38 including a circular area which is in axial alignment with the internal diameter 39 of a band-like transfer head 40, when that band or head is in its retracted position to the left, as viewed in FIGURE 4, ready to receive a new gear G to be shaved as well as to discharge a gear previously shaved. Transfer head 40 is reciprocated by a plunger frame 41 received in a pneumatic control chamber 42 similar to the chamber 33 of FIGURES l, 2 and 3, in which its reversals of movement are governed in timed relation to the incidents of the operation of the apparatus.

As in the first embodiment, movement of head 49 to the right transports and positions a gear to be shaved in axial alignment with the chuck 20, after which the gear is placed in the chuck by pushing head 26, locked therein, shaved and ejected in the manner referred to previously. However, in this instance, ejection of the finished gear by the provisions to be described causes the same to be displaced into the transfer head 40, the head having partaken of a second stroke into alignment with the chuck to receive the ejected gear. So repositioned in the transfer head 40, the next movement of the latter conveys the finished gear to the left, i.e., back to its starting point.

By reference to FIGURE 5, it will be noted that a pneumatically operated transfer cylinder 43 is appropriately mounted in axial alignment with the transfer head 40in this last mentioned position. Cylinder 43 contains a piston (not shown) which is operated in timed relation to the other parts, and its function is to effect the simultaneous transfer of gears to be shaved into, and shaved gears out of, the head 43. Thus, the piston in cylinder 43, in displacing unshaved gear G out of feed-in chute 38, i.e., to the right as viewed in FIGURE 5, causes that gear as it is received in transfer head 40 to eject a finished gear from the head into the discharge chute 44, along which it gravitates to a disposal point or collector.

Turning now to FIGURE 6 of the drawings for structural details of the chuck gear clamping and ejecting provisions according to the invention, the embodiment of the invention presented for the purpose of illustration provides a chuck proper 2t} fitted with an annular adaptor ring 45 bolted thereto. As illustrated in FIGURES 6 and 7, this ring has three equally spaced recesses 46 in its exposed forward edge which receive and accommodate movement of the individual angularly shiftable gear clamping dogs 47. Each dog 47 has a reversely directed clamp nose 48 engageable with the outer face of a gear G, and the dog is carried as a rigid forward nose piece of an angularly and axially shiftable operating rod 49, each rod 4? being slidably received in an individual bore 50 extending through the chuck proper 26. The rod 49' is provided with a shaped cam slot 51 in the form of a modified helix, which slot receives a fixed pin 52 carried by a plunger 53 in a bore 54 of the chuck. It is evident that upon axial movement of the rods 4-9, the clamp dogs 47 of the latter will be moved axially to and from the outer face of chuck adaptor 45, and a gear G therein, as well as to swing into ti piloted in bores 66 in the rotatable cage or frame '56 of the chuck 20.

A plurality of elongated, forwardly projecting ejector rods 68 are provided for the purpose of stripping finished gears G from the chuck adaptor 45. In the illustrated form, there are three of these rods, spaced equally in the circumferential sense, and each is received in a corresponding bore 69 which extends through an inner radial flange 70 of the chuck proper 2i Forwardlyof this flange, the adaptor is provided with correspondingly spaced rounded grooves 71 in alignment with the respective bores 69; so that the ejector rods 68 are free to move and strip a gear G from the chuck when actuated to the right as viewed in FIGURE 6. The rear ends of the ejector or stripper rods 63 are afiixed to a header plate 72 mounted centrally on an actuator plunger 73 of the unit. This is a loose rotatable connection, allowing header plate 72 and rods 68 to rotate with chuck 20 without imparting any rotative torque to plunger 73. Header plate 72 is provided with apertures 74 to accommodate the heads of bolts 75 which secure the other rotatable shaft header 62 to its tubular shaft 61.

The pin actuator plunger 73 extends axially through the bore 76 of hollow shaft 61, in which it is mounted by an anti-friction bearing 77. Tubular shaft 61 is in tuprn journaled by a ball bearing assembly 78, the inner race of which is suitably clamped to the shaft, and the outer race of the bearing assembly is clamped to and abutted at its rear by the cup-like forward extension 79 of a tubular actuator 80 which is operated pneumatically in the clamp cylinder 18 applied to work support 17 (FIG. 2). The ctuating plunger 73 received in hollow shaft 61, and also extending axially through actuator 73, is similarly actuated pneumatically in the ejecting cylinder 19 of the apparatus.

It is of coursecontemplated that in the normal operation of the machine the cutter 1 6 will not always engage on its inward stroke in accurate angular register with a gear clamped in head 20. It is therefore desirable that provision be ma e to insure the proper entry of the cutter,

which is a conventional type having an annular series of cutting teeth, in meshed relation to the teeth of the gear blank, the end motion taking place under limited end and out of position to overlap the gear face and clamp the same.

Chuck 2%) is secured by bolts to a hollow rotary mounting frame 56, which is in turn bolted at its rear to an elongated bearing tube 57 appropriately journaled by roller bearings 58, and appropriately sealed also, in the interior of the work support 17 of the machine. To this sleeve the necessary gear provisions, designated 59, are applied to effect positive rotation of chuck 26 from the motor 22 as a prime mover.

Reciprocating movements of the clamp arm control rods 49 are in response to axial movements of a hollow tubular shaft 61 which extends axially to the rear through rotatable tube 57. A centrally apertured header plate 62 is bolted to the forward end of hollow shaft 61, and a plurality of equally spaced radial actuator bars 63, three in number in the illustrated unit, are in turn bolted to the header plate 62, so as to form in effect a radially extending spindle spider. The spindle bars 63 are notched or bifurcated at 64 on their outer ends, these forked portions straddling reduced portions of the respective clamp arm control rods 4?. The rear ends of the rods 49 are pressure. Meshing will be facilitated by the use of a special cutter tooth form having a tapered entry nose which will lead the cutter into the gear Without undue clash even if the angular alignment is not exact; however, in the alternative or in supplementation of the use of a special cutter form, an arrangement such as is shown in FIG. 8, for controlling the cutter stroke may be employed. This will insure that the cutter is initially presented to the gear G under a controlled, low end pressure, without clash.

As illustrated in PEG. 8, a suitable control cylinder 81 is mounted in fixed relation to the cutter actuating cylinder 210i FIGS. 2 or 5, and the internal bore 82 of cylinder $1 is appropriately connected with the pressurized side of cylinder 21. A control plunger 83 slidably mounted in cylinder bore 82 is thus subject to the pressure on the piston (not shown) in cylinder 21 which urges cutter 16 for its operating stroke.

A coil spring 84 is disposed in cylinder 81 between plunger 83 and the closed end of the cylinder and resists movement of the plunger under this pneumatic force. The plunger is adapted to uncover a by-pass or bleeder passage 85 leading from control plunger bore 82 in the event the pressure on the plunger exceeds a value predetermined by the strength of the spring.

Accordingly, in the event the cutter, in being pneumatically advanced on its operating power stroke, should fail to mesh in the desired degre with the gear G, so that the end interference gives rise to an increase in pressure in cylinders 21 and 81, plunger 83 will yield to the left. Under sufiicient pressurization, this exposes the by-pass 2' passage 85 and bleeds the overpressure, whereupon spring 84 restores the plunger to the right.

The by-passed air may be voided to atmosphere if desired, or it may be returned to the power cylinder 21 on the side of its piston (not shown) which will tend to cause the piston to take a slight shift to the right. An ensuing application of pneumatic power to cylinder 21 will reengage the cutter with the gear G at a different point. An early automatic engagement without damage to gear or cutter is insured by the thus produced jogging action of cutter 16.

It is believed that the operation of the improved apparatus will be understood from the foregoing description. In the embodiment illustrated in FIGS. 1, 2, and 3, gear G gravitates towards chuck 26 in chute 36, from which they are received by the transfer cradle head 31 when the latter is in its lefthand position. Suitable valving .(not shown) within housing 33 controls the horizontal shifting of cradle 31 to the right to position the gear G in axial alignment with the chuck 20. The pushing head 26 now swings downwardly, in a plane paralleling the movement of transfer cradle 31 into axial alignment with chuck 2 0, under the control of a piston or plunger (not shown) in pneumatic cylinder 2%; and upon reaching alignment with the chuck, the pushing arm 27 of head 28 is shifted inwardly of the chuck by ram in-out cylinder 28. Head 26 displaces a gear G from cradle 31 into the chuck 20 following which head 26 returns and retracts upwardly, the gear is clamped in the chuck, is machined by cutter 16, is unclamped and is ejected from the chuck in a manner hereinafter set forth. Pushing head 26 again returns at this point into axial alignment with the chuck, serving as a backstop for the ejected gear.

Upon ejection from the chuck, the gear gravitates, in the embodiment of FIGS. 1, 2 and 3, to a discharge zone along the chute 35.

The embodiment illustrated in FIGS. 4- and differs from that just referred to solely in respect to the manner in which unfinished and finished gears are handled. In this case, the gear blanks are laterally transferred from the feed-in chute 38 into the ring-like or band-like transfer head 40 by means of an auxiliary transfer cylinder '43. Transfer head 49 shifts the gear into axial alignment with chuck 2.0 on a first stroke, returning to the left to allow the cutter 16 to operate. Following the finishing of the gear by cutter 16, the head 40 again moves. It is again hydraulically shifted to the right, under the control of pneumatic valving (not shown) in housing or chamber 42. It there receives a finished gear ejected from the chuck and then returns to the left to its original position. Ensuing operation of the laterally acting transfer unit, which is powered by cylinder 43, causes an unfinished gear blank to be shifted into the head 4%}, in turn ejecting a finished gear G from the head 4%, from which it gravitates along discharge chute 44 to a disposal or discharge point. Upon the reception of a gear blank in chuck 20, the clamping dogs47 on rods 49 are swung inwardly to clamping position and are axially engaged with the outer side of the gear blank upon axial move ment of the rods as to the left, as viewed in FIG. 6. Swinging of the dogs is effected by the camming engagement of the rod slots 51 with the fixed pins 52 of the chuck (FIGS. 6 and 7). The cutter 16 then engages the gear blank, initially under the yieldable control of the by-pass provisions shown in FIG. 8, whereupon the gear is finished in a conventional fashion.

Upon completion of the machining, the dogs 47 unclamp the gear G as rods 49 are shifted to the right, and move to a radially withdrawn position. Ejector pins or rods 63 now shift to the right as viewed in FIG. 6 and :shift the gear G out of chuck 24), against pusher head 26 and onto the transfer head, whereupon the pins 68 are retracted. Transfer head-4Q of the embodiment of FIGS. 4 and 5 takes a second stroke in the cycle, into alignment \with chuck .20 to receive the gear as distinguished from 8 the single feed stroke of the head 31 in the form of FIGS. 1, 2 and 3.

The loose rotative and axially fixed relation of the pin or rod carrying header plate '72 on central plunger 73 enables the plate and rods 68 to rotate with chuck 20, without rotation of plunger 73. On the other hand, the tubular shaft 61, on which the clamp actuating rods 49 are mounted by rotatable plate 62, may rotate in its rear ball bearing assembly 78, the outer, rotatively fixed race of which assembly is operated axially by a rotatively fixed, axially movable actuator 79. This actuator is in turn operated under the control of the clamping cylinder 18; the ejecting rods 49 are similarly operated through plunger 73 under the control of the pneumatic ejecting cylinder 19.

Reference has been made above to the fact that pressure bypassed in the control valve structure 81 may be voided to atmosphere or may be returned to the power cylinder 21, for a repetitive stroke cycle of the cutter involving strokes of substantial length, as compared to the tapping or jogging effect otherwise produced by the bypass action. It is of course evident that provisions to these ends, which no doubt will suggest themselves in one form or another to those skilled in the art, may be incorporated individually and separately in the apparatus. However, there is shown in FIGURE 8 an arrangement for combining the same for an option in this regard. In FIG- URE 8, the bypass passage 35 is shown as being connected through a nipple 86 with a three-Way valve 87 which has a pressure fitting 88 leading to atmospheric pressure, or to a suitable receiver (not shown) in the event hydraulic pressure is to be employed to actuate the machine. Valve 87 has a further discharge fitting 89 which, in a pneumatic installation, leads to a suitable diaphragm type actuator t). A control rod 91 extends from the spring-biased diaphragm (not shown) of the unit 90. The control rod 91 has a pivotal connection at 92 to a contactor of a switch which controls the flow of current in an electrical circuit which governs the application of pneumatic or bydraulic pressure to the actuator for cutter 16. As contemplated herein, this circuit may include arrangements to reverse the action of the pressure liquid in cylinder 21 and thereby create a reversal of the stroke of cutter 16 when a contact is momentarily made by switch contactor 93. Provisions to this end have not been illustrated, but will be obvious to those skilled in the art.

Supplementary provisions may be course be made in the gear loading apparatus as generally described above for various control purposes. For example, it may be desirable for the purpose of adjustment, and to regulate the stroke of certain pneumatically controlled members, to provide a unit such as is shown in FIG. 7 and generally designated 94. The purpose is to control the stroke of the piston in cylinder 29 which operates the ram 23 on the oscillatory movement of its radial arm 27. To this end, the unit 23 may consist of a rigid arm 95 atfixed to an outwardly extending end of a plunger 96 which operates in cylinder 29. The arm carries at its top a laterally extending slide beam 97 which is guided in fixed brackets 98, and a member 99 adjustably clamped on beam 97 carries a tappet 1610. This tappet is engageable at opposite extremes of the movement of plunger 96 with fixed stops 101, thus limiting the swing of ram arm 27, and enabling the swing to be accurately adjusted, so that the ram clamp head 26 aligns accurately with the chuck 20 in its operative loading position.

Provisions of this sort may also be made to control the clamping-unclarnping, axial movements of the ram; however, in the interest of simplifying and clarifying the drawings, specific illustration of appropriate units, such as the unit 94 of FIGURE 7, has been omitted from the remainder of the figures.

The drawings and the foregoing specification constitute a description of the improved method and apparatus for loading internal gears in such full, clear, concise, and

exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What We claim as our invention is:

1. Loading apparatus for a gear finishing or like machine comprising periodically operating means receiving and positioning articles to be finished, said means including a longitudinally shiftable head transferring said articles in axial alignment with and axially outwardly of a rotatable work holder of said machine, a transfer member periodically engageable with an article aligned with said work holder by said transfer head, said member being mounted for swinging movement in a vertical plane paralleling the direction of movement of said transfer head, and means to shift said transfer member axially inwardly toward said work holder to displace an article from said transfer head of said positioning means onto said work holder, said head guiding saidarticle in the displacement of the latter by said transfer member, said receiving and positioning means further including a gravitational article feed chute having a discharge end posi tioned in lateral alignment with and on one side of said transfer head in a retracted position of the latter, a gravity discharge chute having its receiving end in lateral alignment with said retracted position on the opposite side of said transfer head, and an auxiliary transfer device periodically operative to shift articles from said feed chute discharge end onto said transfer head and from the latter onto said receiving end of said discharge chute.

2. A loading apparatus for a gear finishing or like machine comprising periodically operating means receiving and transporting articles to be finished into position in axial alignment with and axially outwardly of a rotatable work holder of said machine, a transfer member periodically engageable with an article aligned with said work holder by said transporting means, and means to shift said transfer member axially inwardly of said work holder and transversely of the path of said transporting means to displace an article transversely from said transporting means onto said work holder, said transporting means slidably guiding said article in the displacement of the latter "by said transfer member, and being formed to permit said engagement of the transfer member with the article to so displace the latter.

3. Loading apparatus for a gear finishing or like machine comprising periodically operating means receiving and positioning articles to be finished, said means including a longitudinally shiftable head transporting said articles into axial alignment with and axially outwardly of a rotatable work holder of said machine, a transfer member periodically engageable with an article aligned with said work holder by said transporting head, and means to shift said transfer member axially inwardly of said work holder and transversely of the path of said transporting head to displace an article from said transfer head of said positioning means onto said work holder, said head slidably guiding said article in the displacement of the latter by said transfer member, and being formed to permit said engagement of the transfer member with the article to so displace the latter.

4. Loading apparatus for a gear finishing or like machine comprising periodically operating means receiving and positioning articles to be finished, said means including a longitudinally shiftable head transporting said articles into axial alignment with and axially outwardly of a rotatable work holder of said machine, a transfer member periodically engageable with an article aligned with said work holder by said transporting head, said member 10 being mounted for swinging movement in a vertical plane paralleling the direction of movement of said transfer head, and means to shift said transfer member axially inwardly of said work holder to displace "an article from said transfer head of said positioning means onto said work holder, said head slidably guiding said article in the displacement of the latter by said transfer member, and being formed to permit said engagement of the transfer member with the article to so displace the latter.

5. The improvement in a gear finishing or like machine, comprising a rotatable work holder, and period'- ically operating means receiving and positioning articles to be finished on said work holder, including means receiving and transporting articles to be finished into position in axial alignment with and axially outwardly of said work holder, a transfer member periodically engageable with an article held so aligned with said work holder by said transporting means, and means to shift said transfer member axially inwardly of said work holder and transversely of the path of said transporting means to engage and displace an article transversely from said transporting means onto said work holder, said transporting means slida-bly guiding said article in said displacement of the latter by said transfer member, and being formed to permit said engagement to the transfer mern'ber with the article to so displace the latter.

6. Apparatus in accordance with claim 4 in which said transfer member includes a ram mounted for axial and swinging movement about an axis paralleling and spaced from the axis of rotation of said work holder.

7. Loading apparatus in accordance with claim 4 in which said receiving and positioning means further in: cludes a gravitational article feed chute having a discharge end positioned adjacent and in gravitational sup ply relation to said transfer head in a retracted position of the latter, and a gravity discharge chute having its receiving end in gravitational receiving relation to said work holder.

8. Loading apparatus in accordance with claim 6 in which said receiving and positioning means further includes a gravitational article feed chute having a discharge end positioned adjacent and in gravitational supply relation to said transfer head in a retracted position of the latter, and a gravity discharge chute having its receiving end in gravitational receiving relation to said work holder.

References Cited in the file of this patent UNITED STATES PATENTS 668,665 Veeder Feb. 26, 1901 953,752 Neureut-her Apr. 5, 1910 1,794,424 Smith et a1. Mar. 3, 1931 1,876,372 White Sept. 6, 1932 1,945,662 Smith Feb. 6, 1934 1,946,429 Smith et a1. Feb. 6, 1934 2,577,946 Bailey et al. Dec. 11, 1951 2,581,928 Broden Jan. 8, 1952 2,646,087 Jobert July 21, 1953 2,660,929 Praeg Dec. 1, 1953 2,692,536 Gates Oct. 26, 1954 2,693,133 Moncriefi Nov. 2, 1954 2,696,986 Grobey Dec. 14, 1954 2,733,072 Hohwart Jan. 31, 1956 2,733,641 Praeg Feb. 7, 1956 2,782,689 Carlsen et a1. Feb. 26, 1957 2,793,040 Wilson May 21, 1957

Images