3 2 1 4 9 2 5 3 3 United States Patent Office ,,tented Sept. 22, 1964 3,149,533 GEAR FINISI-HNG MACHINE or to Alfred Gliic7A, Karl.-@M=-Stadt, Germany, assign VEB zahnscbneidemaschinenfabrik Modal, Karl-YiaA-xStadt, Germany 5 Fil.-d Oct. 19, 1959, Ser. No. 847,131 6 Claims. 90-1.6) This invention relates to a machine for finishing gear teeth and siinilar par"s and in particular to a n@-vi and 10 useful machine of this character having a novel drive arrangement permitting rapid acceleration and deceleration of the shavin.- gear in each direction. The present inient@.on is directed to a r-riachine whicn finds particular application for finish machi-iiing of pre- 15 cut -ears by a shavin,@ process in which the shaving mechanism must be rapidly accelerated and decelerated in either direction. A prime reqiiirement for th-e operation of such ma-,hines is thel the abrading tool or wh-,el be accurately driven and moved in the desired direction 20 to perrnit satisfactory abrading of the gears which must be accurately fmished to dimensions specified withi@i small tolerance limi@s. In such mach--Ies it is usual that gears have to be worked on in rapid succ--ssion and it is neez-,ssary to pro,,,ide automatic loadine or charginde- 25 vices, therefore, @.n order to cut down the oderatintime of the machin-,. Since the abradi--,g or shaving operatio-n on the -Car teeth is a prec;sion operation the machine must be built very rigidly and the feeding mecnanism for the worl--niece must be stable and op-.rate smoothly 0 and free of oscillacon. In previous devices of this character, since tue rotation of the shaving -,car had to be reversed rep,-atedly and ac@-elerp,ted in each direction to high s-oceds, it was usual to provide a long -Car train from the drivin.@ motor to 35 the shav:in,- tool. -vliith such a construction it was necessary to accelerate and decelerate lar,-e gear masses in order to operate the machine. In accordance with the present 'mvention there is provided a novel drivin.@ mechanism for the shavin,@ tool 40 which includes a sprin@ biased worm gear affixed to the shaft of the drivin.- motor and which may be urged aa.ainst its sprin.- biasing in either direction dur,.Dg the startup in order to perinit mov,-ment of the gear out of mesh with the worm to permit initial absorption of thrust 45 prior 'Lo the aclual drivin,a of the Nvorm and the mach;n-@ .,having gear. The driving mechanism constructed in accordance -with the -presenl invention is very compact and alt'@ou.-h it is easily accessible from the top of the machine it is enclosed and is an accident proof construc- 50 tion. Accordingly, it ;s an object of this invention to provide an improved machine for finishing mecnanical parts such as g,-@qrs. A further object of the invention is to provide an 55 abrading machine for gear teetti which is highly accurete and incl-ades a &iving mechanism for the shaving member having means for absorbing drivitig thrusts for acceleration and deceleration in either d;rection. it, is a further object of the inv@-@ition to provi'de a 60 shaving machine whicb is easily accessible and which has a vibration proof bearing arrangement for the workpiece. A furth,-r object of the invention ;s to provide a sbaving machine includin.@ drivin.- means 'Lor impqrting to 65 the shaving gear the necessary rotation through the shortest possible means in order to avoid loss of pmver when the direc'ion ol' rollation is reversed and to provide a vibration free drivin,@ gear train i-Ti which the several 70 members will not be subjected to excessi-,,e wear. A further obj,-ct of the invention is to Drovide a gear 2 tooth shpvin- machine which is completely enclosed and accident proof. A f-lirther obje-,t of the inveition is to provide a shaving machine wh-ch is simple in design, rugged in construction and economical to manufacture. The various features of no-@eity which characterize the itivention are pointed out with particularily in the claims aniiexed to and forming a part of this specification. For a better Linderstandin- of the invention, its operating advantages and sp,- cific objects obtained by its use, reference should be had 'lo the accompanying drawings and descriptive matt,-r in which ther iS illustrated and de.e scribed a preferred embodiment of the invention. lp thedrawings: FIG. 1 is a front elevation of a gear tooth finishing machine constru-@ted in accordance with the invention; FIG. 2 is a vertical section taken on the line 2-'-7 of FIG. I and indicating means for autoiratically feeding viorlpieces to the shaving tool in succession; FIG. 3 is a front elevation s;m;iar to FIG. 1 but ind-:cating the standards of the machine in an elevated position for machning a large workp@ece; r-IG. 4 is a pers7,,-@ctive view of the machine completely enclosed ar@d wit@out the automatic workpiece feeding mechani m; -S FIG. 5 4s a sor@iewhat schematic horizontal section taken on the line 5-5 of FIG. 1; FIG. 6 is a sect-Ion taken on the line 6-6 of FIG. 5; and FIG. 7 is a somewbat enlarged Dartial showing of one of the workp-l,-ce holditig sleeves sl@o,,vn in FIGS. I and 3. Referrin- to the drawings in particular the invention as embodied there@n i-@icludes a shaving machine for gear fin,.shing havi@ig a base 1, on each end of which is mounted an upstanding standard 2, 2'. Between the standards 2, 2' is a wor-kpiece sil-pportin.@ base or console 3 wll,:ch is mounted for vertical reciprocat@on pref-erably guided on inwardly eTAending portions 82, 82' of each of the standards 2, 2'. The outer reciprocable port:.on of the console 3, of course, may be -Uided on one side by the standard 2 proper and may also abut against a portion of the other standard 2' in order to achieve a vertical rec.Procation. A shaving head 4 is moil-n'Led on a slide 5 which ;s vertically reciprocable o-@i the console 3 by conventional mear@s schematically exempiified by a telescopic mechanism "3. Head 4 is rotatable in a substantially horizo-tital plane with resp-.ct to slide 5 by means of a diseshai)cd member 4a (FIG. 6) embedded in the slide, as best seen in FIG. 2. The slide 5 includes suitable guide members 60 slidlng in riinways 61 of the console 3 to permit rec-1procation of the shavin@@ head 4 and to perniit its own sed;mg movement on the console 3 (see FIG. 2). Each ol' the standards 2, 2' includes inwardly extendin.- and horizon,@ally reciprocable work-piece supporting spind'..- sleeves 8, 8'. Means are provided to permit adjustnient of the -leeves 8, 8' toward and away from each other 'in order to clamp a workpiece 6 therebetween. By way of example, FTIG. 7 is a somewhatschematical showing of sleeve 9 reciprocably guided in a portion of the standard 2. One of the simplest means known in the art is the provision of a rack 69 operable by means o'@ a pinion 63, rotatable from outside. The sleeves 8, 8' may be filted with convent;onal centering points as shown at 62. The sleeves 8 are arranged so that the workpiece 6 mdy be riaidly held above a shavina. gear 7, the workp@@'Ccc and the shaping wheel being h:eely accessible from the f@-ont, rear and top of the device. The workpiece 6 may rotate when acted thereupon by the shaving gear 7. I'L should be noted that FIGS. 1-3 do not show the shavin- -ear 7 in an operating position with respect to the

workpiece 6; in FIGS. I and 3 the form-er is rotated by about 45 degr,-es while in FIG. 2 it is shown axially aligned with the latter, for the purpose of better showing the shaving head 4 and its attachments, to be described hereunder. As seen in FIG. 5 the driving mechanism for the shaving gear 7 includes a two-speed drive motor 9 which may be an electric or hydraulic or other suitable device, which is enclosed in a casing 10. The casing 10 is provided with internal passageways 11 for the circulation of a cooli-ig liquid for the motor as w-.11 as means for slpplying liquid for cooling the workpiece during@ the shaving operation. Keyed to the output shaf t of the motor 9 is a worm 12 which is centrally biased by means of springs 13 and 14 held at their outer ends by bearing riembers affixed to the. shaft. and having their inner ends abulting against the worm 12. The worm 12 rotates with the shaft of the motor 9 but may move back and forth axially thereon as mdicated by the arrow in FIG. 6. The worm 12 is b;ased centrally into meshing engagement with a worm wheel 16, but Lipon initial rotation of the worm 12 in either direct;on it fails to rotate the worm wheel 16 until the i-riitial rotational forces are absorbed by either the spring 13 or the sprin.a 14. The worm wheel 16 is loosely motnled on a shaft or spindle 15, rigid with a thicker shaft portion which carri6s the shaving gear 7. The worm wheel 16 is a double .-Par having a spur gear portion 17 with ax-lahy extending coupling teeth 18. In the. position indicated in FIG. 5 the sdur gear 17 meshes with a pinion portion 33 of a double gear 20. The doible gear 20. has a gear portion 32 at its opposite end which meshes with a gear 21 afflxed to. the thicker portionofaftl5. Thus,driveis@frommotor9through v;orm 12 to wheel 16, from spur gear 17 through pinion 33; of gear 20 and thence, through gear portion 32, to gear 21 affixed to shaft 15. In accordance ivith the invention there i-S provided a switch 23 which is pivotally mounted o@i a sta+,ionary portion of the frame and includes- a forked portion 34 which is connected to the double gear 20 to pern-iit axial shifting of the,latter on a shaft 19. The switch 23 also includes a portion engaging a coupling member 22 which is splined on the spindle shaft 15 for rotation therewith but may move axially in respect th@-reto. When the switch 23 is@ actuatect from the position indicated in FIG. 5 the forked portion 34 moves the pinion 33 of the double gear 20 oiit of engagement with the spur gear 17 and causes the coupling 22 havina laterally extending mating coupeng; portions 84, to engage correspondin.- portions 18 of the gear- 17. The driving arrangement then is through the gear 16 to the coiipling 22 which rotates the shaft 15. The purpose of gears 33, 32 is to act as an intermediary gearing to bring about a reduction to low speed. At the higher rate of revolutions transmitted over the coupling portions. 84, 13, however, the double gear 20 should not revolve so@ as to avoid@ accelerating the additional mass during the frequent changes in the direction of revolution. Hence the gear 20 with portions 32, 33 is shifted to the right (as seen in FIG. 5) and is automatically disengaged from the respect@.ve gears 21, 17 when direct coupling is established be+ween the gear 16: and the shaft 15. The arrangement permits the driving of the shaving tool- 7 by means of the motor 9 through the shortest possible gear train having good efficiency so that it maY be driven by a comparatively low horse power motor 9. The@ arrangement also p@-rmits many gear speed drivinratios through either an electric motor or a continuously adjustable hydraulic motor. The gear driving mechanism isi such, that only the parts which are positively nlecessary for the trans.-mssion of torque rotate at any given time. When the direction of rotation is to be changed only a few-parts which are of light weight and hence low in mass have to be accelerated or decelerated. Any thrust 3,149,533 41 forces prodticed by this acc.-leration or deceleration are taken up by the axially movable worm 12. When th-. mol.or is started the worm 12 moves in an axial direction out of its meshing engagement wilh the worm 116 against tl-e action of '@he spring 13 or 14. The springs are of sufficient torqiie so that the worm will move out of driving engagement with the. worm wheel, and, after the spring initially absorbs the inertial forces, an equilibrium is established to permit the worm to move back into full 10 driving engagement with the worm wheel 16. As the worm wheel 16 starls to rotate the worm 12 it reassumes its normal driving operatin.- position. Such a construction obviates the necessity of providing a brake for the drive motor, hence the gear train is not subjected 1 5 to 'Lhrusts due to th-, worm -ear 12 being axially movable and resiliently mounted. The construction prevents overload of the drive molor 9 which may be likely to occur during any change of direction. The mechanism also provides a means for absorbing 20 thrusts which may occur during the operation of the shaving gear against the, workpiece. Any unusual obstacles which are encountered by the shaving gear 7 are absorbed by the worm IL2 and converted into an axial movement by the self-braking property of the worm drive. None of 25 these unusual thrusts are transmitted to the motor. The gear driving mechanism described permits at least fwar different speeds in each di,-ection by use of a twospeed motor. Such speed variation has been found to be completely sui%cient for aR practical purposes. 30 In FIG. 3 the standards 2, 2' are shown elevated on their inner portions or spacers 24, 24' to support a workpiece 6a of large diameter. The machine may be supplied with o@- without the inner portions or spacers 24. The standards 2, 2' with the base I form a substantlauy 35 U-shaped frame which pernuts great flexibility in the positioning of the workpiece. The complete device, may advantageously be enclosed by a cover piece 25 having a transparent flap 26 which is closed after the workpiece 6 has been placed in the machine; (FIG. 4). The Ra@ is 40 provided with a window 85 through which the work- can, be observed. All means for the control@ and operation of the automatic finishing procedilre may be placed within the interior of the machine frame or cover 25. In FIG. 2 there is indicated a means for automatically 45 supplying the machine with several workpieces 6. In this embodiment a cross beam member 27 is positioned so that it extends across the machine between the standards 2, 2' ' The bndging or rross beam member 27 is provided with a worl,piece seating or feeding device 28 50 (see FIG. 1) which includes a supplyin-. chute 31 (FIG. 2a) which effectively permits the delivety of workpieces 6 down onto the feedling device 28 which is vertically aligu-ed with the workpiece positioning sleeves 8. The supply of w<)rkpieces may be controlled by sensing devices 55 29 and hydraulic or pneumatic pipes oi@ connecting elements 30 which may be suitably mounted on standards 2, 2'. Since the feeding deyiee 28 is always in a fixed connection with the machin,e ftame duri,ng operation the short covered pipes 30 are not likely, to be subjected to 6o wear. This vrevents interruption of the operation and accidents. A machine which is built as described above may be used,without any additional equipnient in a production line, or@ may operate separately as an independent, unit 65 completely automatically. The machine according to the invention is notlimited to use as a shaving device for the flanks of gear teeth. it m ay, -for instance, also be used as a gear lapping machine. Thus, the invention provides a machine including an 70 open U frame construction which permits aceessibility to the workpiece from either side or the top of the machine. Both the workpiece support and the mounting standards are easily adjustable @and means are provided to accurately position the workpiece for operation thereon by the 75 shaving tool.

5 While a specific embodir-ren-t of the inver@tion has been shonvn and d.-scribed in detail to illustrate the auplication of th.- invention principles, it Nvill be understood that the invention may be embodied otherwise without departing from such principl-.s. What is