CA1050309A - Rotary forming machine and tool - Google Patents

Abstract

ROTARY FORMING MACHINE AND TOOL
ABSTRACT OF THE DISCLOSURE

A rotary forming machine and a rotary tool utilized therewith for performing a forming operation on a workpiece. A
work spindle rotatably mounts the workpiece about a first axis and a pair of tool spindles which each support a plurality of the tools are rotatably mounted about spaced second axes on opposite sides of the first axis. Each tool has a partially circular forming face extending about the associated tool spindle axis for an angle less than 180 degress with forming projections that engage the workpiece. Associated pairs of the tools on the two tool spindles cooperate with each other to simultaneously form the workpiece in an opposed relationship to each other. Each tool includes a metallic body with a leading end and a trailing end between which its forming face extends as do base and side wall surfaces. The rotary tools preferably have elongated shapes with maximum heights that are approxi-mately 25 percent of their length. The tool spindles are mounted for movement toward and away from each other to permit the forming of workpieces of different sizes, while a pair of tension members prevent movement of the tool spindles away from each other. The forming projections on the rotary tool are disclosed as teeth for providing a splining or gear forming operation. During forming of a workpiece, a double enveloping worm gear drive train for the tool spindles, a timing gear drive for the work spindle, and a drive control cooperate to provide precise forming.

Description

3~
BAC:KGROUND OF THE INVENTION
~ield of the :rnvention , The present invention relates to a rotary forming ma-chine and to a rotary tool utiliæed therewi~h to form a ~70rkpiece.

Description of the Prior Art One type of conventional forming machine incorporates a pair of reciprocal gear racks having teeth that oppose each other as the racks are reciprocated into a~ opposea relationship on opposite sides of a workpiece. -Engagement of the teeth ~n the gear racks with the workpiece causes a forming operation to take place that forms the workpiece with t~e desired configura-tion. Machines of this type are ~isclo~ed by United States Patents 3,214,~51 and 3,793,866. Gear racks which may be uti--î lized with this type of machine are aisclosed by United States Patents 2,994,237; 3,015,243; a~d 3,672~203.
Another type of ~orming machine ~tilizes rotary form-ing tool~ to form a workpiece. A pair o~ such tools are rotat-ably supported in a spaced relationship to each other.. The periphery o these tools defines a forming face that engages the workpiec~ to provide the forming operation. ~nited States Patent 2,886,990 discloses one such forming machine in which substantially the -total 360 periphery of each rotary tool defines its forming face. Eash of the tools also has a re1ie~ea area that allows loading and unloading of the workpiece to take place between the two tools of the machine. E~ch cycle of the machine is thus perEormPd as the tools rotate one revolution about their respecti~e axes. Another similar machine is dis-closed by U. S. Patent 3,201,964. The ro~ary tools of ~his S~9 machine each have a pair of Eorming faces on their periphery.
Consequently, a complete forming operation is performed by a one-half revolution of the tools. Damage or wear to either of the forming ~aces on one of the tools requires replacement of the tool even though the other forming face i5 still usable.
Another similar rotary forming machine is disclosed by U.S.
Patent 3,~30,058.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a rotary forming tool comprising a metallic body having a leading end and a trailing end and a partially circular forming face extending between the leading and trailing ends thereof; the forming face being generated about an axis external of the body and including forming projections located thereabout for an angle less than 180~; said body including a base mounting surface extending between the leading and trailing ends thereof so as to mount the tool on a tool spindle and also including side walls extending between the base mounting surface and the forming face; and the base mounting surface being oriented toward the axis about which the forming face is generated.
A rotary forming machine on which the rotary tool is used includes a work spindle and a pair of tool spindles rotatably mounted about spaced second axes on opposite sides of the work spindle. A plurality of the rotary tools are mounted on each tool spindle in a circumferentially spaced relationship. Each tool includes a partially circular forming face having forming projections that extend about the associated tool spindle axis for an angle less than 1~0. A partial revo-lution of the tool spindles engages the forNIing faces on asso-ciated pairs of the tools with the workpiece on the work spindle

-2-P-310 ~(15~13~93 so as to perform a forming operation. The rotary tools are mounted on the tool spindles in a manner that permits any one of the tools to be removed and replaced and independently of the , other toolsO
The rotary tool includes a metallic body having a generally flat base mounting surface and side wall sur~aces that extend between the tool forming face and its base mounting surface. The tool spindles have radial mounting surfaces seating the base mounting surfaces of thP tools and including radial projections that extend between the tools and the tool spindles at their engaged surfaces to cooperate with attachment members in securing the tools in position.
Each tool spindle of both machine embodiments disclosed is rotatably mounted by an associated support housing that is slidably mounted by a slideway on a base of the machine. Between the tool spindle support housings, the work spindle supports a workpiece to be formed such that movement of the support housings toward and away from each other allows workpieces of different sizes to be formed.
In one preferred embodiment, the tool spindles are driven by a pair of electric motors with their rotations coor-dinated by a spur gear drive. Horizontally spaced portions of each tool spindle support housing and a shaft extending there~
.::
be~een cooperate to support the associated tool spindle.
Another preferred embodiment includes a double envelop-ing worm gear drive train for driving the tool spindles in a coordinated manner with each other as well as a timing gear drive for driving the work spindle in coordination with the tool spindles. A pair of shafts of the gear drive train are inter-5~3~

connected by a slidable coupling and have respective worms meshed with a pair of worm gears coupled to the tool spindles. A pair : of motors respectively drive the shafts to rotate the tool spin-dles. ~rea contact ~etween the worms and the worm gears pro-S vides precise driving control of the tool spindles and conseguent precise formation of workpieces being formed.
The timing gear drive is driven by an input shaft off one of the worm gears and is connected by timing change ge~rs to the input of a dif ~erential . An output of the dif ~eren~ial drives a timing gear drive output shaft that is coupled with the work spindle to provide rotation thereof in a coorainated man-ner with the tool spindles. ~n a~justing shaft extends from ~he differential to a losatiorl just below ~he work spi~dle to permit timing adjustment of the work spindle wi~h respect to 1~ the tool spindles. ~he other woxm gear of the gear drive train is coupl~d with a shaft of a driv~ control of the machine. The drive control shaft includes aogs that actuate a switch for con- ¦
trolling the machine operation. A parallel relatlonship exists between the input and output shafts of the timing gear drive and ~0 the adjusting shaft thereof as well.as with the drive control shaft. These shafts are all orie~ted perpendicular with respect to the pair of motor driven shats having the worms that drive the worm gears~
A pair of adjustable tension members extend between the tool spindle support housings on which the tool spindles are mounted at locations above and below the tool spindles. During forming of a workp.iece, these tension members prevent movement of the support housings away from each o-ther so as to provide precise forming during rotation o~ the tool spindles and the work spindleO Opposite ends of the tension members are threaded ~0~3C~
to receive nuts that engage the tool spindle support housings.
Between their ends, the tension members extend through spacers located between the tool spindle support housings such that the ti~htening of the nuts compresses ~he spacers between the hous-ings.
~ he rotary forming tool disclosed includes a metallicbody having a leading end and a trailing end between which the forming ~ace and flat base mounting surface extend~ Side walls of the tool body are oriented perpenaicular to the flat base mounting surface and exten~ therefrom ~o the forming face~ Qne of the side walls may function as a mounting surface that seats against an associated axial mounting surface of the tool spin-dle.
The metallic body of the rotary tool is preferably cast 15 from molten metal to provide a surface having the partially circular configuration of i*s forming face~ The forming pro~
jections are then machined into this surface. These forming projectio~s may take the form o teeth that perform a splining or gear forming operation on the workpiece. ~s disclosed, the forming projections are embodied as teeth that extend parallel to the axis about which the partially circular forming face extends. ~owever, it should also be pointed out tha~ ~he forming projections may also be embodied as threads for per forming a thread rolling operation on a workpiece. Addition-ally, the rotary tools mounted on each tool spindle do not ne-- cessarily have to perform the same forming operation during each partial revolution o~ the tool spindles. Por example, with three rotary tools on each tool spindle as disclosed, three ~ifferent forming operations could be performed during each one-third revolution of the tool spindles.

5 _ ~5~3~

The forming face of the rotary tool disclosed prefer-ably -extends about the axis of its associated tool spindle ~or an angle less than 90. The tool has an elongated shape whose maximum heigh~ between its base moun~ing surface and its forming face is approximateIy 25 percent of the length of the tool. This tool shape readily lends itself for mounting on a tool spindle which receives two other similarly shaped tools so as to perform the same forming operation during each one-third revolution o~
the tool spindles.
The objects, features and aavantages of the presen~ in-- vention are readily apparent form the following detailed de~crip-tion of the preferred embodLments tak:en in connection ~ith the accompanying drawings.

B:E~IEF DESCRIPTION OF THE DRAWI~;S

FIGURE i is an elevation view showing ~ne embodiment of a rotary forming machine and associated rotary formin~ tools that embody the presen~ invention; .
FIGURE 2 .is a plan view of ~he machine ta~en i~ section-along line 2-2 o~ FIGURE l;
PIGURE 3 is ~n elevation view of the machine in section taken along line 3-3 of FIGURE l;
FIGURE 4 is an enlarged view showing one of the rotary . tools of the invention;
FIGURE 5 is a view of the tool taken along line 5-5 of FIGURE 4;.
FIGUER 6 is a view of the tool ta~en along line 6-6 of YIGURE 4;
- FIGU~E 7 is a partial view of a modifiea embodiment o~
the rotary forming tool;

~ 6 -Sa~3~
~ IGURE 8 is a perspective view of another embodiment of a rotary for~ing machine accorcling to the invention; and ~ IGU~E 9 is a perspec~ive ~iew of a tool spindle gear drive train, a work spindle timing gear drive, and a drive con-trol of the machine shown in FIGURE 8.

DET~ LED DESCRIPTION OF THE ~REFERREU EMBODIMENTS
,_ , . _ ~.
Referring to FIGURE 1 o~ the drawings, one em~odLment of a rotary forming machine 10 and rotary tools 12 utilizea ~here-with are construc~ed according to ~he present invention and cooperata to perform a orming operation on a circular wor~piece ~ 14. A work spinale 16 rotatably supports the workpiece 14 abou~
a first axis A on a floor mounted machine base lB. ~ pair of tool spindles 20 are rotatably supported on spaced secona axes i B by tool spindle support housin~ 22 that are also mounted on :: 15 the machine base 18. Each tool 12 includes a partially circu-lar forming face generated about the associated tool spindle axis B with -the tool in the mounte~ relationship shown. The forming face of each tool includes forming projections 24 that . extend about the associated axis ~ for an angle less than 180 and, preferably, for an angle less than ~0 when there are three such tools mounted on each tool spindle as shown. ~uring a partial revolution o~ the tool spindles ~0 in the directions shown by arrows 26 t the forming proj~ctions 24 of the tools engage the workpiece 14 to perform a ~orming operation. This engagement rotates the workpiece in the direction shown by arrow 28 and causes the Eor~ing to proceed about the total periphery thereo~ with each tool performing the forming on one-half of the periphery.

~5~3al~
Each of the rota~y fonming tool~ 12 may be removed from its associated tool spindle 20 and replaced with another tool without removing the other mounted tools. Thus, i~ one tool becomes damaged or worn, it 'may be replaced without requir-ing removal of the other still usable tools. As shown, theforming projections 24 of the tools are embodied as teeth that perform a splining or gear forming operation. However, it should be pointed out tha~ these forming projections could also be embodied as threads for per~orming a thread rolling operation.
Also, the associated pairs of rotary tools 12 that cooperate with each other to perform the forming operation during each partial revolution of the tool spindles 20 do not necessarily have to be the same as the other associated pairs of tools.
Thus, a di~ferent forming operation may take place during each partial revolutio~ of the tool spindles whe~ different tools ar~ utilized. This feature gives the machine ~he capability of performing different forming operations in a sequentially repeating cycle without re~uiring any tool set-up operation.
Furthermore~ if a sufficient supply of one of the par~s being formed is presently on hand~ the machine may simply be cycled through the partial revolution of the tool spindles that causes t~is forming operation without mounting a workpiece on the work spindle 16. Great flexibility in meeting production schedules is thus possible with -~his machine.
Referring to FIGURES 4 through 6, the forming projec~
tions 24 on the rotary tool shown take the form of teeth for performing splining or gear making operations, as was previously stated. The rotary tool 12 is formed fxom a cast metallic body 30 ~7ith an elongated configuration that has an upper partially circular surface. Tool body 30 has a leading end 31a and a ~ 5~3~9 trailing end 31b between which its forming face having the .forming teeth 24 extends. Teeth 24 are machined into the form-ing face after the casting operat:;on that provides the tool body. In the preferred embodiment which is utilized as one of three similar tools on the associated tool spindle, the forming projections or teeth extend about the rotational axis of the tool spindle for an angle less than 90. This ro~ational axis is locatea externally of the ~ool boay in the opposite direction toward which the forming teeth project. As shown, these teeth extend parallel to the ro~ational axis across the $otal width of the tool body~
As seen by continuing reference to FIGURES 4 through 6, the rotary tool 12 includes a generally fla~ base mounting surface 32 extending between the leading and trailing ends 31a ana 31b o~ the tool body. In the pre~erred embodiment s~own, base mounting surfac~ 32 is elongated and has its plane parallel ~o the axis about which the forminy face o~ the tool is generated.
The base m~unting sur~ace 32 engages a coopera~le radial moun~-ing surface 34 on the tool spindle 20 in the mounted relation-ship shown. End attachment flanges 36 at each end of the toolare secured to the spindle by suitable attachment members ~uch as the bolts 38 that are threaaed into the spindle 50 as to.
maintain an engaged condition of ~he mounting surfaces 32 and 34~ Side walls 40 of the too~ body 30 extend hetween its forming face and its base mountlns surface 32 and, pre~erably, -: are oriented perpendicular to the surace 32 ana parallel to each other. O~e of the side walls 40 p.rovides a side wall mounting surface ~hat faces a pair of flanges 42 on the tool spindle and engages an axial mounting surface 44 cooperatively defined by these flanges. Attachment members such as ~he ~ OS~3iD~
bolts 46 shown maintain an engaged condition between the ~ide wall and axial mounting surfaces ~0 and 44 to also secure the tool in position.
As seen in FIGVRE 4 t a radial projection 48 extends be-tween the tool spindle 20 and ~he ~ool body 30 at their inter-engaged mounting surfaces 32 and 34 so as to cooperate with the attachment bolts 38 and 46 in se~uring the tool body on the spin-- dle. The radial projection 48 is preferably located midw~y be-tween the leading ~nd trailing tool body ends 31a and 31b, As shown in FI~UP~E 5, the projection 48 has an end received between the flanges 42 ~f the tool spindle. Preferably, the radial pxo-jection 48 is mounted on the tool spindle projecting ou~wardly to be received within a slot or opening 50 in the tool ~ody.
Projection 48 is also received within a 510t 54 in the tool spindle and is secured in position to th~ spinale by a bolt 56 shown by hidden lines in FIGURES 4 and 5.
; With reference to FIGURE 7, an alternate embodiment of the rotary forming tool is indicated by 12'. Th~ ~eneral shape of ~his tool 12' is the same as tool 12 but it includes groups of forming teeth 24a, 24b, 24c along its forming face.
The teeth wit~in each group have the same size, but the teeth have a progressively increasing size from one group to the next moving in a direction fxom the leading end o the tool ~ody toward its trailing end. The smaller teeth first engage ~he workpiece to provide the initial forming with the larger teeth - subsequently completing the forming operation. The smaller teeth as well as the larger teeth have a tool profile that is conjugant to the final shape to be formed in the workpiece.
Thus, from the tip of the smaller teeth 2~a to their roots, the same shape ;s defined as from the tips of the larger teeth

3~
toward their roots for a correspondin~ distance.
~ ith combined reference to FIGURES 2 and 3, each tool spindle 20 is rota~ahly mounted on the machine base 18 by an associated shaft 58 of its respective support housing 22. A
slideway 62, FIGUR~ 3, of the machine base 18 slidably mounts the support housings 22 for movement to~ard and away from each other. This movemen~ enables the machine 18 to accommodate workpieces of different sizes on its work spindle and to still perform the forming operation. Each support housing 22 includes a main poxtion 64 and an upwardly extending portion 66, FIGURE
3, that is secured to th~ main portion ~y bolts 68. The hous~
ing portions 64 and 66 are oriented in a horizontally spaced relationship and respectively support antifriction bearing assemblies 70 and 7~ that cooperatively rotatably mount the associa~ed tool spindle shaft 58. Intermediate these housing portions 64 ~nd 66, the shaft 58 is received within a central opening of the associated tool spindle 20 which is rotatably fixed thereto by ~eys 74, FIGURES 2 and 3. Adjacent their ou~er ends the shafts 58 each include a reduced diameter portio~ 76 that is received within the associated bearing assembly 72.
Plates 78, FIGURE 3, locate this bearing assembly within a suitable apert-lre 80 in the housing portion 66. A threadea portion 82 of each shaft 58 receives a locking nut 84 that locates the tool spindle 20 against a flange 86 of the shaft~
This ~lange 86 is al50 seated against one side of the bearing assembly 70 and a threaded por-tion 88 of the shaft on its .
other side receives a locking nut 90 that is seated against the other side of this bearing assembly~ An associated bear-ing mount 92 supports each bearing assembly 70 on its associ-ated main housing portion 64 within an aperture 94 o~ the main 3~
housing portion. Bolts 95 secure the bearing ~ounts 92 to themain housing portions 64.
A spur gear train colllectively indicated by 96, FIGURES 2 and 3, extends between the two tool spindle shafts 58 to synchronize the rotation of each with ~he other. The drive train includes an input spur gear 98 mounted on each shaft 58 and rotatably fixed thereto by k~ys 100. A threaded portion ~02 of each shaft 58 receives a locking nut assembly 104 that seats the associated input gear 98 against the th~eaded shaft portion 88 that receives locking nut 90. The lower side of each input gear 98 is meshed with an associated intermeaiate gear 108, only one being shown in FIGU~E 3. -A common gear 110 shown only partially by phantom lines in ~IGURE 3 is meshed with both of the intermediate gears 108 so that the gear train 96 synchro-nizes the rotation of the shafts 58 and the tool spindles 20carried by the shafts. It should be noted that the common gear 110 must be adjustably mounted for vertical movement so as to maintain its meshing relationship with the gears 108 despite adjustment of the tool spindles 20 to allow forming of workpieces o~ diffexent sizes.
Each of the tool spindle suppoxt housings 22 incluaes an end portion 112 and a bottom portion 114 as seen in FIGURES
2 and 3. Bolts 116 secure the end and bottom housing portions 112 an~ 114 to the main housing portion 64 as well as securing the end and bottom housing portions to each other. A chamber - 118 of each housing 22 is cooperati~ely defined by its portions 64, 112, and 114 and receives the associated input gear 98 of the synchronizing gear train ~6. The tool spindle sha~ts 58 project into the chambers 118 to rotatably support the input gears 98 for rotation within the chambexs. The ~nd housing 5~309 portion 112 of each support housing 22 supports an associated elec~ric motor 120 that drives the sha~t 58 through a coupling 122. Motors 120 are secured to the associa-te~ housing por~ions 112 by bolts 124 and include splined outpu~ shafts 126 received 5 within internally splined central openings 128 of the couplings, A splined end portion 130 of each shaf t 5~ is also received within the coupling opening 128 so as to be driven by the as-sociated mo~or 12~ through the coupling 122.
With reference to FIGURE 2, each bott~m housing por~
tion 114 i~cludes a bearing mount 132 that supports a pair of antifriction be~rings 134. A shaft 136 is rotatably supportea by the bearings 134 and carries the~in~ermediate gear 108 - meshed with the associated input gear 98 and the common gear 110 shown ~y phantom lines. The tool ~pindle support housings 22 L 15 include flanges 138 and 140 on the housing portions 64 and 114, respectively, and these flanges cooperate with a parallelogram spacer 14~ in preventing upwar~ movement of the ~ousing from the machine base slideway 62. However, hori~ontal movemeAt of the housing portions toward and away from the work spindle is permitted to accommodate different size workpieces as pre~iously discussed. Adjustable nut and bolt assemblies 14q shown in FIGURE 1 provide the impetus for moving the tool splndle support .
housing ~2 toward and away from the work spin~le. These nut and bolt assemblies extend between th~ housings 22 and associated brackets 146 mounted on the machine base 18 by bolts 148.
Adjustable wedge-block assemblies 150 also extend between the brackets 146 and the housings 22 to provid~ reinforcement for the positioning of the tool spindle housings 22 during the forming operation performed by the machine. Each wedge-block assembly 150 includes a wedge-block 152 fixedly mounted on the .

3~19 associated housing 22 by one or more bolts 153, FIGURE 2, and an adjustable wedge-block 154 engaged with the wedye-block 152 and slidably movable between slide flanges 156 on the adjacent bracket 146. ~he upper end of each adjustable wedge-block 154 is connected wi~h a threaded shaft 158, FIGURE 1, recei~ea with-in a threaded bearing 160 mounted on an upper flange 162 o~ the associated bracket 146. The upper end 164 of the sha~ts. 158 receive a suitable wrench for rotating the shafts and thereby moving the adjustable wedge-blocks 154 ~ertically. This ver~
cal movement allows the wedge-block assemblies to reinforce the positioning of the housings 22 in any a~justed position against outward movement away rom each other during the forming opera-tion of the machine. A common brace 166 is secured to the flanses 162 of the brackets 146 by bolts 168 so as to mainta~n the brackets 146 against deflection that could cause movement of the t~ol spindles. Also, each of the tool spindle housings 22 carries a scale 170, FIGURE 1, that is aligned with a visual- .
ly observa~le mark 172 on the machine base 18 to position the tool spindles for performing the forming operation on workpieces of a predetexmined size.
As seen in FI5URE 2, the work spindle 16 is supportea by a housing 174 that is secured to the machine ba~e 18 by bolts 176. An insert 178 receives an end portion 180 of the spindle with a press fit and is itself received within a central open-ing 182 in the housing 174. An ejec~or assembly 184 is utilizedto remove the spindle 116 from the housing insert 178~ This ejector assembly includes a threaded shaft 186 that is threaded into a nu-t 188 secured to the end of insert 178. Shaft 186 is also suppor~ed by a cap 190 secured to ~he end of housing 174. A spring 192 encircles the shaft 186 and is seated ~615gJ 3~
against the cap 190 and a flan~e 19~ of the shaft ~o as to blas the shaft and thereby provide ~riction that prevents rot~tion except when a wrenc~ is applied to its end 196 ~o eject the spin-dle 1~.
Ano~her embodiment of a rotary forming machine con-structed according to the inven-tion is shown by ~IGURES 8 and 9O
As seen in ~IGURE 8, the machine is collectively indicated by reference numeral 200 and includes a floor base 202 having a slideway 204 OII which a pair o~ support housings 206 are mounted for slidable movement toward and away from each other. Each sup-port housing 206 includes a base plate 208 that slides on the slideway and has downwardly depending flanges 210 that oppose each other ana receive respective edge strips 212 of the slide-way in a capt.ure~ relationship. On top o~ each base plate 208, the housings 206 include hollow box-like portions 214 ~ith front and rear walls ~16 and 218 (see also FIGURE 9~ for ~upportins shafts 22~ on which the tool spinales 222 are fixealy moun~ed.
Each tool spindle has three flat mountin~ surfaces 224 oriented in a radial direction with respect to the associat d shaft 220 and spacea circumferen~ially thereabout in an equally spacea relationship. Rotary tools 12 are mountea on each mounting sur-face 224 by attachment members 38 and have the same construc~ion as either the tool described în connection with FIGURES 4 through 6 or the modified tool described in connection with FIGURE 7 so that the tool ~ounting surfaces 32 engage those.of the tool spindles. Spindle m3unting surface projections 226 are received within openings in the tool mounting surfaces 32 to locate the tools in cooperation with attachment me~bers 38 in the same man-ner prevlously described.

36~
Between each tool spindle 222 o~ the machine emb~diments in FIGURES 8 and 9, a work spindle 228 is supported on the end of a sha~t 230, FIGURE 9. Phantom line indicated support portions 232, shown in FIGURE 9, of the machine base 202 (FIGURE 8) sup-5 port the work spindle shaft 230 for rotation about an axis A~A workpiece 234 suppor-ted on work spindle 228 ~hus rotates about axis A between spaced axes B through shafts 220 on which the tool spindles 2 22 rotate.
With re~erence to FIGURE 9, a worm gear drive train col-lective~y indicated by 236 drives the tool spindles 22~ in a coordlnated manner with each other. Drive train 236 includes a pair of shafts 238 that are respectively supported or r~tation on the support housings 206 (FIGURE 8) ~n a suitable manner with their ou~er ends driven by an associated hydraulic motor 24~.
Inner spline~ ends 242 of shafts 238 are connected by a s1idable splined coupling ~44 that allows the shafts to moYe tsward and away from each other as the housings 206 are adjusted $o accom-modate workpieces of different sizes. Between their inner an~.
outer ends, the shafts 238 ~ach include a worm 246 meshed with an associated worm gear 248 fixed to ths associated tool spin-dle shaft 2200 Along their axial lengths, each worm 246 has a concave shape for partially receiving the associated worm gear 248. Likewise, the round peripheries of the worm gears Z48 also have a concave shape along their axes of rotation so as to par-tially receive the associated worms ~46. This type o~ wormgear drive set is referred to as being "double enveloping" and provides area co.ntact in driving the tool spindle ShaLtS 220 so as to rotate the tool spindles to form the workpiece 23~ It has been found that this type of drive will give precise form-ing of workpieces formed by the machine. During such forming, SID3~
the coupling ~44 coordinates the xotation o~ each tool spindle : 222 with the other tool spindle.
A work spindle timing gear drive 250 of machine 200.isshown in ~IGURE 9 and includes an input or inpu~ shat 252 driven 5 by one of the worm gears 248 in a coaxial relationship with the associated tool spindle shaft 220. Shaft 252 is mountea within the left-hand support housing 206 shown in ~IGURE 8 in a rota-table man~er on support portions 254 indicated by phantom lines in ~IGURE 9. A spur type timing change gear 256 mounted on 1~ shaft ~52 drives an intermeaiate spur type timing change gear .258 which itself drives another spur type timing change gear ~59 A differential 260 of the timing gear drive includes an inpu~
shaft 262 rotatably mounted on a support portion 264 o~ the ma-chine base. The timing change gear 259 is fixea on shaft 262 and drives the differential whose output or output shaft 266 is connected with the work spindle shaft 230 and, in fact, may form an integral continuation of the shaft. Differential 260 re~erses the direction of rotation between its inpu~ shaft 262 and its output shaft 266 by conventional gearing and has a spur type a~justment gear 268 affixed to its output shaft. Another spur type adjustment gear 270 is meshed with gear 268 and fixed onto one e~d of an adjustment shaft 272. The mac~ine base sup-port portions 232 that support shafts 230 and 266 also rotatably support adjustment shaft 272 which extends forwardly so that i~s forward hexagonal end 27~ is located between ~he tool spindles 222 below work spindle 228. Rotation of adjustment shaft 272 by a suitable wrench applied to its hexagonal end 274 causes the meshed adjustment gears 268 and 270 to rotate the work spin-dle 228 relative to the tool spindles 222 for timin~ aajustment.
Reverse driving ~ the differential 260 by forces applied to ;ts output shat 266 does not cause driving of the input differenkial 3~56~3 [)9 shaft 252 so that ~his timing adjus-~ment of the work spindle with respect to the tool spindles is possible.
A drive control of machine 200 i5 shown in FIGURE 9 and indicated collec~ively by numeral 276. This drive control in-cludes a shaf~ 278 driven off the worm gear 24~ opposite theone that drives the timing gear drive 250. Shaft 278 is coaxial with the tool spindle shaft 220 driven by its associated worm gear ~48 and has a rear end plate 280 carrying three dogs 28~.
An actuator 284 of a switch 286 is engaged by the dog5 282 dur-ing opera~ion of the machine so as to terminate the tool spin-dle rotation after each partial revolution so that the formed workpiece can ~2 removed from th~ work spindle ~?8 and another workpiece to be formed can be mounted on the work spindleO Dur-ing its rotation~ the control shaft 278 is supported by spacea ~: 15 support portions 286, shown by phantom lines in FIGURE 90 of the FIGURE 8 right-hand support housing 206~
It should be noted that the machine shafts shown in .
FIGURE 9 are preferably supported on thei~ associa~ed suppor~
housing and machine ~ase support: portions by antifriction b~ar-ings in the same manner disclosed in connection wi-th ~he machine el~bodiment of FIGURES 1 through 3. Also, the shafts 220, 230~ 252, 262, 266, 272, and 278 are all oriented in a paralleI relation-ship with respect to each othar and in a perpenaicular relation-ship with respect to the sha~ts 238 of the gear drive train 236.
With re~erence to FIGU~E 8, each support housing 206 includes an adjustment mechanism ~88 (only one shown~ haviny a plate 290 mounted on the machine base 202 and a shaft 292 with an outer hexagonal end 294 mounted by the plate. An inner end of shaft 290 is threaded and recei.ved by a fixed nut o th~ as-sociated support housing so that rotation of the shaf~ moves the - 18 ~

~ ~S~3~9 support housing toward and away frc)m the other support housing~
Each support housing can thus be adjust~d so that the tool spin-dle 222 can be adjus-ted with respect to the workpiece axis A
to foxm different sized parts. After the support housings 206 have been adjusted to the proper location, a pair of tension me~-bers 294 prevent movement o~ the housings away from each other so as ~o provide precise forming. Each tension member has an elongated configurati~n with a pair of threaded ends 296 extend-ing outwaraly past a side plate 298 of the adjacent support housing. Nuts 300 and associated washers 302 are received by the threaded tension member ends 296 ana engaged with the hous-ing side plate~ 298. Between the support housings 206, apertured spacers 304 of appropriate thicknesses are sanawichea be~ween housing flanges 306 with interm~aiate por~ions of tension mem-~ers 294 extending through the spacer apertures. Tightening of i nuts 300 thus compresses the spacers 304 and concomitan~ly ten-sions ~embers 294 wlth a preload to prevent outward movement of the tool spindles 222. One of the tension members 296 is located above the tool spindles 2 22 and the other is located below the 20 tool spindles, but each tension member is in vertical ali gnment with the tool spindles so as to prevent the movement o~ th~
suppor housings in a balanced manner.
Precise forming of workpieces can be achieve~ by the maohine 200 due to the cooperable action of the dou~le envelop-~5 ing worm gear drlve train 236 shown in FIGURE 9 and the tensionmembers 294.shown in FIGURE 8.
While pre:Eerred e~bodiments have herein been described in detail, those skilled in the art will recognize various al-ternative embodiments and designs for practicing the present invention as defined by the following claims.

Claims (12)

What is claimed is:

1. A rotary forming tool comprising a metallic body having a leading end and a trailing end and a partially circular forming face extending between the leading and trailing ends thereof; the forming face being generated about an axis external of the body and including forming projections located thereabout for an angle less than 180°; said body including a base mounting surface extending between the leading and trailing ends thereof so as to mount the tool on a tool spindle and also including side walls extending between the base mounting surface and the forming face; and the base mounting surface being oriented toward the axis about which the forming face is generated.

2. A rotary tool as claimed in Claim 1 wherein the mounting surface is fiat and oriented parallel to the axis about which the forming face is generated, and the side walls also being flat and extending perpendicularly from the flat base mounting surface to the forming face such that one of the side walls can function as a side wall mounting surface.

3. A rotary tool as claimed in Claim 2 wherein the metallic body includes attachment flanges at the leading and trailing ends thereof.

4. A rotary tool as claimed in Claim 3 wherein the metallic body defines an opening in the flat base mounting surface midway between the attachment flanges at the leading and trailing ends of the body.

5. A rotary tool as claimed in Claim l wherein the forming projections are teeth.

6. A rotary tool as claimed in Claim 5 wherein the teeth extend parallel to the axis about which the forming face is generated.

7. A rotary tool as claimed in Claim 5 wherein the teeth are arranged in groups along the forming face, the teeth within each group having the same size and the teeth having a progressively increasing size from one group to the next group moving in a direction from the leading end of the body toward the trailing end thereof, and the smaller teeth as well as the larger teeth having a profile that is conjugate to the shape to be formed in the workpiece.

8. A rotary tool as claimed in Claim 1 wherein the forming face has forming projections thereon for an angle less than 90°.

9. A rotary forming tool comprising: an elongated metallic body having a leading end and a trailing end; said body having a flat base mounting surface and a partially circular forming face disposed in oppositely oriented direc-tions and extending between the leading and trailing ends thereof; the forming face being generated about an axis located externally of the body in the direction toward which the base mounting surface is oriented and including forming teeth located thereabout for an angle less than 180°; and the body including flat side walls extending parallel to each other in perpendicular orientations from the base mounting surface to the forming face.

10. A rotary tool as claimed in Claim 9 which has an elongated shape having a maximum height between the base mounting surface and the forming face that is approximately 25 percent of the length of the tool.

11. A rotary tool as claimed in Claim 9 wherein the metallic body is a casting whose forming face is machined to provide the forming teeth.

12. A rotary forming tool comprising: an elongated metallic body having a leading end and a trailing end; said body having a flat base mounting surface and a partially circular forming face disposed in oppositely oriented directions and extending between the leading and trailing ends thereof;
said body including flat side walls extending parallel to each other in perpendicular orientations from the base mount-ing surface to the forming face; the forming face being gener-ated about an axis located externally of the body in the direction toward which the base mounting surface is oriented and including forming teeth located thereabout for an angle less than 180°; the teeth being arranged in groups along the forming face and having the same size within each group but a larger size from one group to the next group moving in a direction from the leading end of the body toward the trailing end; and the smaller teeth as well as the larger teeth having a profile that is conjugate to a shape to be formed thereby in a workpiece.