US1732561A - Rate-changing mechanism - Google Patents

Description

E. J. KEARNEY ET AL RATE CHANGING MECHAISM Filed Dec. 31, 1925 5 Sheets-Sheet l M4 www@ ATTORNEYS.

Oct. 22, 1929. E. J. KEARNEY ET Al.

RATE CHANGING MECHANISM 5 Vsheets-sheen 2 Filed Dec. C51, 1925 A TTORNEYS.

Oct. 22, 1929. E 1 KBARNE??4 ET A 1,732,561

RATE CHANGING MECHANIS Filed Dec. 31, 1925 5 sheets-sheet 5 (QM FEM, @www A TTORNEYS.

E. J. KEARNEY El' AL.

RATE CHANGING` MECHANISI 5 Sheets-Sheet 4 Filed Dec. 51, 1923 NVE TOR`V /w @9%4@ ATTORNEYS oct. 22, 1929. E, Jf KEARNEY ET AL 1,732,561

RATE CHANGING MECHANI SM Filed Dec. 3l, 1925 5 Sheets-Sheet 5 IN V EN TOR.

Patented @et 22, i929 cart; sTA'rr-:s

PATENT OFFICE EDVIARD J. KEARNEY, OF WA'UWATOSA, AND JSIH ARIVVTAGE, F MILVAUKEE, W'EGUITSIN, ASSBGNORS TO KEARNEY-TBECKER`CORPORATOII, OF WEST ALLES,

RATE-CHANGING MECI-IAN ISM Application filed December 3l, 1923. `Serial No. 683,648.

lhis invention relates to improvements in rate changing mechanism or elia-nge speed wearing and, more particularly, to a rate cnanger adapted t'or use upon machine tools and comprising a mechanism in which relative changes in speed are effected by the replacement or interchange oi' particular elements. y

lt the primary object of this invention to provide novel and improved means for the operative connection of a driving With a driven element at Widely variable rates of relative speeds. More particularly stated, it is cnr object to provide tor the Wide range ci speeds aforesaid with relatively small increments ol" change.

lt is a Jfurther extremely important object ot this invention to provide a rate changer through which two operative driven elements may be interconnected. for operation at various relative speeds with either ot said elements at a ii'elzltively higher speed than the eener. y

Eis indi fated above, it is contemplated that i rate changer hereina'lt'ter to be disclosed, will find lield o'l' usetulness in connection with machine tools and particularly, with the driv' ip; trains leading.;` to the Work suptale and to a Work supporting1 indie, such as may be mounted as an at- Lt upon such a table. Accordingly, it is a further object el this invention to provide a rate chan er which, in conjunction 'di driving trains having` certain characterics hereiiiaiter to be described, Will besuc- Ae oi' adjustment 'lor the actuation of the two driven elements aforesaid at relative i provfling` tor the leads necessary to tie clit-ii'ijg` ot threads oi all standard types. )t is purpc er, further, to provide not only :or the cutting of standard threads, but also f he cuttingr oi threads which differ to ous minute degrees lroin the threads Ordinarily recognized standard. In this manner, it is our purpose to provide for the cumin o'2 threads in metals which are known to be sub, to contraction or expansion dureir subsequent treatment. It will be ,tcod by these skilled in the art that an operator provided with a rate changer 'tion may be clearly brent-ht ont.

embodying' this invention will be able, in cuttingthreads in a piece oi Inet-al which is later to be hardened or otherwise treated, to

compensate in advance 'for the expansion or contraction which is expect-ed to occur in the metal during such treatment.

Further objects of this invention are to gaming will nevertheless be accessible when the changes in adjustment are necessary; to provide -a rate changer in which relative speeds oi the drivingl and driven elemcntsare raided by taking oil Lgears from their respective `shafts and substitutin` others and in which an. extremely Wide range of adjust* ment with small increments ot' change is possible with the use oi connaaratively few individual gears; and in general, to improve, simplify and render more convenient rate chang'i i' mechanism of the general typeto 4 which ive have referred to herein. y lillhile this `application is directed particularly to the rate changer per se, the disclosure will nevertheless include the application 'of a rate changer, einbodyint;` this invention, 'to a milling` machine, in order that the advantaggeous functions which may be accomplished through the use of this inven- For this pinpose, the rate changer is shown to be attached to a milling1 machine table in a .manner adapted to establish variable relative rates ot movement betiveena dividinghead spindle and the table actuating` `member or screw. The machine will he discussed from the standpoint of millingmachine practice and the means by which various spiral leads may be cut will bc described. i i

ln the following description it will be noted that biieie reference will be made to the subject matter oit various connjanion applications as follows: i

ll e application Vot E. J. Kearney reladting1 to a dividing head, filed April 24, 1923, Serial No. 634,292.

The application of E. J. Kearney and yJoseph Armitage relating to a machine tool o-f said table and the work supporting or driving spindle of a spiral-cutting dividing head, such as forms the subject matter of application Serial No. 634,292, above referred to.

Figure 2 is a developed view in plan of the mechanism housed within the rate changing device shown in Figure 1 as connected with special driving mechanism housed within a machine tool saddle beneath the table and disclosed more particularly in the companion applicaton of Joseph Armitage, Serial No. 643,290, above referred to.

lFigure 3 is a section taken on line 3 3 of the developed view shown in Figure 2.

Figure 4 is a developed sectional view taken on line 4 4 of Figure 5, and illustrating the meansby which the rate changing mechanism may be attached to a machine tool table..

Figure 5 is a fragmentary detail, partly in horizontal section, of a means for clamping the rate changing mechanism to the machine tool table. i

Figure 6 is an end elevation of a housing in which rate changing mechanism embodying this invention may be assembled.

Figure 7 is a front elevation of the same.

Figure 8 is a section taken on line 8 8 of Figure 7 Figure 9 is a detail of one set of change speed gearing incorporated in the rate changing mechanism as it appears in a section taken on Vline 9 9 of Figure 10.

Figure 10 is an end elevation of the mechanism shown in Figure 9.

Figure 11 is a section taken on line 11 11 i of Figure 6.

' Like parts are identified by the same'reference characters throughout the several A views.

A machine tool table shown at 10 may be reciprocable in the usual manner upon the machine tool saddle 11 within which is housed driving mechanism described in detail in the Armitage application, Serial No. 643,290. This driving mechanism will be very briefly described herein. The bevel pinn ion, indicated at 12, is driven through a t rain, not shown, from some source of power extraneous to the machine. For the purpose of this description, the bevel pinion 12 may be considered to be itself a source of power.

Journaled for reciprocation with the tan ble are two parallel shafts, one of which comprises a table actuating screw 13 and the other of which constitutes a power shaft 14'. At one end of the table, each of these shafts will preferably be provided with clutch meinbers shown at 15 and 1G, respectively.

The axis of shaft 14 passes immediately above the bevel gear 12 and a pair of bevel gears 17 and 18 mounted concentrically with shaft 14 in constant mesh with gear 12 and are` thereby interconnected for simultaneous rotation in opposite directions. Splined to shaft 14 are a pair of clutch members 20 and 21 which are connected for simultaneous axial movement upon said shaft. A handle 22 upon an oscillatory roch shaft 23 serves to transmit movement to the clutch members and 21 through the teeth 24 upon the rock shaft and racl; teeth 25 upon the clutch member 21. The arrangement is such that when the handle 22 and rock shaft 23 are tilted in either direction from the neutral position in which they are illustrated, one or the other of the clutch members 20 or 21 will be engaged with the hub of gears 18 or 17, re` spectively, to receive motion from the gear so engaged and to actuate power shaft 14 in either direction accordingly. rlhe clutch members 20 and 21, since they move in unison, may be considered as a single clutch de` Vice through which shaft 14 may alternative ly be connected with either of the oppositel)` rotatable gears 17 and 18 to receive power therefrom.

Freely rotatable and concentric with respect to shaft 14 and axially movable on said shaft is a sliding clutch pinion 27 which is provided with a peripheral groove 28 within which a forli 29 is operatively engaged for the shifting of the pinion. The pinion is provided upon each of its ends with clutch teeth which, by the sliding movement of the pinion, are alternatively engageable respectively with complementary teeth upon the gears 17 and 18. The axial sliding movement of pinion 27, by means of which it may be coupled with either of the gears 17 or 18, is controlled by means of a rack bar 30 which carries the shifting fork 29. A handle 32 at the forward side of saddle 11 is oscillatory with a rock shaft 33 which carries a rack gear 34 meshing with a rack 35. F rom rack reciproeatory motion is transmitted to rack 30 through the medium of a pair of connected rack gears 3G and 37.

7 Splined to the screw 13 is a gear 40 which issutiiciently broad so that despite any possible axial adjustment of clutch pinion 2'?, the pinion and said gear will always remain in niesh. The silined connection et weer L0 u l 1 n n D witl screw iciis adapted to permit the screw to neovo oxiall" throun'h said Gear with the a tame l() while the rear maintains its position within the saddle. Screw 13 operates through a hired nut ill which is held to the saddle h nv suitable ineens such as dov/el l 1i v t* j by the suitable oscillation or flier direction, the clutch teeth n 2T may he brought into fitn one oL the oppositely ronrs li' or i8, thereby causing seid ar t() and trible screw 13 to rotate troiled hy the direction of c j i cipal l? or i8 enaged by pin'on E22. Uliviouslypthe rotation ol the screw 'l-3 in lviny given direction will prodnce o corresponding1 inovenient olf table l through the feeding;` ol the screw 1S through not Lill. tihatt ld will nieve with the screw end tdble7 being; permitted by its splincd connection with clutch elements 2O and 2l to have such movement.

it suitable inteloclring device, d-esignateiil in its entirety hy the retei'enc i character 43, is preferably used to prevent the siinultzxncousI operation ot the screw l' and er shalt let. This device has been 'telly described in the Armitage companion application, above 3o referred to, and need not ii'urtller he discussed herein.

'lhe whole pnrpose or" the driving mechanism thus ifar descrihed to provide 'for he alternative actuation in either direction et eitlre i3 or the power shalt 'lll rein a single source oi.l power, such as gear l2. lt will be reineinhcred that gears l? and 18 are :intere nnected through year 1Q `for continnous rotation in opposite directions. One clutch dence, cf'inrgrisin@` clutch sleeves 20 and Slt, is operahle to connect the power shaft lil with either oi the gears li" or lll and a second clutch device, comprising the clutch pinion 2i', is similarly operable to connect the ew i3 with either et the gears l? or ld, '.lhus these two parallel sheiits, both oit which translate with the table7 may either of thein he dr'vof. in either direction5 although their silnnh ne actnetion is preferably rendered impossible in the practicel use of the present invention.

lldachiniA tool tables are adapter to receive various atcaclnnents und may include work supporting; or driving; spindles permanently ,mounted thereonD For the purposes of this descr p on is desired to illustrate e, verh porting; driving; spindle t( be given f di rate hanging device hereinafter Hed. ily way ci" eiicniplilyi u' of work siupporting;l spindles irted l'rcin inechine ui table attach- 1 a sp The ett-achbcen inore particularly the table screw (ill which tuhle. t .Y

nicht e. i

described in the companion application oit E. J. Kearney, Serial No. @34,29% above reiierred to, and will not he described in detail herein. rlhe attachment may he designated in its entirety hy the reference character d5. It comprises a worlr supporting spindle l-G journaled in :i traine 4:7 which is adiusebly supported above e base member clamped to the table l0. Motion is received into the attaol'nnent through a shait .shown i9 and `is transmitted through the attachment by ineens not .shown here in to indexing mechanisin generally indicated at fl-/l and thence to the work supporting spindle etti. fis 'usual in the case ol dividing head mechanisms of various tyikies it may he understood that the internal inechanisin of the dividing;- head the spindle 16 in the ratio ot Ll-O to l. ahove stated, the special features ot the dividing head, as described in the con' panion application above referred to, are unnecessary to an understanding oil' this invention end accordingly are not illustrated, For the purposes et this description the device l5 may be taken to represent any well known type of table attachment providing for e rotatable, or otherwise independently operable, work suijiport.

'teniovahly mounted upon table 1U is a housing; within which the rate changing inechanisin9 forming the purticuler subject matter of this application, is assembled. The end oi table l0 iney he provided with a dovetailed tongue 51 as shown in Figure l. Ei:- tendingl upwardly troni the lower portion of housing to a shoulder 52 is a complimentary recess 53, one wall portion 54 of which may be laterally adjusted to exert a clamping,- pressure upon the portion 55 of tongue 5l. rlho means by which the lateral adjustment ol ineinloer 5d may be accomplished lnay coinprise a screw 56 in threaded engagement with housing 50 and including1 a tapered portion 57 operating1 in a correspondingly tapered recess 58 in an arno 59 coiinected with ineinber 551i. The arrangei'nent is such that when the screw 56 is turned downwardly it is advanced hy means of its threads to a point where the tapered portion 57 et the screw exerts a, wedging oct-ion on arr 59 to drew the ineinber 54 into binding; engagement with the portion 55 ot dovetailed tongue 51. is a result the entire housing 50 i Ivill he liriniy clamped in the position deiined by its dovetailed engagement with the table and by the limiting shoulder 52 which prevents the downward movement ot the housing beyond a predetermined point. lt vill be obvious that any other clamping` device might be used to engage the rate changer with the table without effecting the operation of the rate hanger as such.

l/Vhen the housing1 50 is chunped in the ehove defined position, shafts 63 and 84; therein will Vbe aligned, respectively, with the table screw 13 and the table power shaft 14.

y Y Each of the shafts 63 and 64 is axially'slidable and 64 are provided at their ends adjacent the table with clutch members and 66 which are, respectively,*engageable with the complementary clutch members 15 and 1G carried by the table screw and table power shaft. The axial shifting movement above referred to, may be utilized to engage and disengage either of the shafts G3 or 6st with the aligned shafts of the table. Thus by the suitable engagement of these clutch members it is possible to receive vpower into housing 50 through either the table screw or power shaft,.whichever of said last mentioned members is actuated from the source of power within saddle 11.`

llhile the mechanism within housing 50 preferably includes at least three sets of reduction gearing, there is nevertheless a trans mission train provided for the direct actuation of the attachment spindle lo from the power shaft 14 without using any of the change speed gearing. A pinion 68 .faston shaft G4 drives a gear G9 which meshes with a central gear 70. Gear 70 constitutes a point of union for a plurality7 of power transmitting trains hereinafter to be described. From this gear are actuated two driven gears 71 and 72 which are preferably of substantially equal size and are preferably j ournaled within the upper port-ion of housing 50 independently of the shafts to which they transmit power. The driven shafts 7 3 and 74 are interchangeably insertable into housing 50 and are provided with lzeyways through which said shafts may receive power from corresponding lreys carried by the gears. Either of shafts 73 or 74 may be utilized conveniently for attachment actuation and which of said shafts is used and which gear, the operative shaft may be engaged with Y will depend primarily upon the nature of the of gear 71 shaft 7a might then be used to the powe tacliinent was disposed adjacent the rear of transmit power from said gear. Shaft 74 will be noted to include a universal joint which is represented at 77. ln the event that receiving element of the table atl. the table7 rather than at the front thereof,

either of shafts 74: or 73 would then be used to transmit power from gear 72 to the attachment. Furthermore, if the attachment included two members which required simultaneous actuation it would be possible to use shafts 73 and 74. simultaneously to accomplish the desired result.

In addition to the operative power transmitting connection above described :is extending between shaft (Si and the two driven shafts 73 and 74 it is to be observed that means is also provided for transmitting power through the central gear 70 between shafts (i3 and G4 of housing 50. ln other words, it is possible through the mechanism contained in said housing to connect the table power shaft 1st and the screw 13. In the power train which is available for this purpose there are preferably three sets of reduction gearing, each of which set may include substitute gears, whereby the rate of motion transmission through cach such set may be varied according to the ratios of the gears used. For the purposes of the present application this change speed gearing of the so-called take-off type is preferred over other forms of change speed mechanisin, since it makes possible the production of an unusually large number of speed changes with an unusually small number of individual gears. Gear G8 has already been described as heilig in mesh with gear (if). Said gear G9 may be mounted upon a relatively fixed stud and may be connected with a worm 81 through which the motion of said gear is imparted to an automatic trip device which will herein be designated iii its eutirety by reference cha 1acter 82 but will not be specifically described. rlhe trip device S2 was described in companion application Serial No. 683,647, above referred to, and an understanding thereof is unessential to an understanding of this invention. It may he pointed out, however, that the trip device operates to move rod 83 axially and, through the movement of a clutch fork 8l connected with said rod and acting upon shaft (ill, to disengage clutch members (i6 and 1G, whereby to disconnect shaft G from power shaft 111-.

From gear (i9, motion is transmitted as above described to gear 70 which is pre ferably fast upon shaft 85. This last mentioned. shaft is connected with a shaft Sii through a series of change speed gears which will hereinafter he designated as Series A.

Shaft 85 is journaled in a bearing sleeve 87 supported by the portion 50 of housing l50. Upon the exterior of the projecting bearing sleeve 87 is journaled a arm or which is provided at 89 and 90 with arcuate slots concentric with the axis of shaft ,86. Set screws 91, in threaded engagement with v r .r f f the poi tion o0 of housing oO, may be tightened upon the portion of the arm adjacent suoli slots to maintain said arm m any posithis chamber a spider or frame 127 is slidably receivable to support from housing 50 a bearing128 for shaft 115. The frame also supports a bearing 129 for a shaft 130 hereinafter tion by a pair of manually operable latch `gears in SeriesVC.

members 132. T he closure plate may conveniently be provided with a. flange 133 adapted to fit within the margin of the chamber intowhich the spider or frame 127 slides. This liangc may abut the frame as shown in Figure 8, thereby securing the frame rigidly in position against'the shoulder 126 of housing 50. The arrangement is such that when the cover plate 131 is removed the entire spider or frame 127 can be bodily withdrawn from chamber 125 bringing with it shafts 115 and 130. When the spider is thus withdrawn it Will be obvious fr m an inspection of Figure 3 that access to the Series B gears is readily afforded through the remaining opening. In fact, one of said gears will necessarily be lwithdrawn with the spider and can be changed in theopen. Toremove gear 116 it is only necessary to reach through chamber 125 and unscrew the nut or other securing means which holds said gear in place, whereupon said gear may be withdrawn from its shaft and another gear may be substituted therefor or the shaft may be bodily Withdrawn throughthe door 121 in the manner already described.

The shafts 115 and 130 which are thus mounted in the removable spider or frame 127 are interconnected by a third set of change gears which will hereinafter be designated as Series C. Thile it is possible to provide any desired number of gears for luse at this point, it has been found necessary for the particular purposes desired and in the particular combination of other gears mentioned herein lto use only four different The gears 135 and 136 which are shown in Figure 2 in mesh between shafts 115 and 130 may have a 1 to 1 ratio. s lin Figure 8, however, are illustrated substitute gears 137 and 133, and which are of the ratio of`1 to 4. rllhe gear 137, as illustrated, is so small as to make its construction for removal from the shaft impractical. Consequently, gear 137 is made integral with shaft115 which may be bodily substituted for shaft 115 or for shaft 36. For the purpose of substituting gear 138 for gear 136, the shaft 130 is provided not only with a keyway, best illustrated in Figure 8, but also with a threaded extremity adapted to receive a lock nut 139. It will be noted that inasmuch as the shaft130 is journaled in bearing 129 of the frame or spider 127,-this shaft, together With shaft 115 or 115', will be withdrawn from the device with the spider. Consequently, in withdrawing the spider to ell'ect a change in the gears of Series B, it is unnecessary to alter or adjust in any way the gears of Series C. rThe Series C gearing is bodily removable from the device with the spider for any desired purpose.

In order to permit of the bodily removal ol shaft 130 from the housing, while preserving the possibility of an operative connection of said shaft with shaft 63 of the housing, there is provided in alignment with shaft 13() a short length of shaft 140 which is j ournaled in a bearing member 141 supported directly from the housing 50. Shafts 130 and 1-10 are provided with mutually complementary clutch members 142 and 143, respectively. These clutch members are so designed that when the spider or frame 127 is properly seated against the shoulder 126, clutch members 142 and 143 will be operative for power transmission between shafts 130 and 140. 1When the spider or frame 127 is withdrawn from the chamber 125 of the housing, clutch members 142 and 143 will be freely separable to permit of the manipulation of the device in the manner already described.

A motion reverser is preferably interposed between shafts 140 and 63. A bevel gear 1-'1-5 carried by shaft 140 meshes with the opposed bevel pinions 146 and 147 which are mounted concentrically with shaft 63 but are free for movement thereon. Not only can shaft (33 be moved axially through pinions 146 and 147, but said pinions are also rotatable with respect to the shaft unless they are secured thereto through the medium of an axially slidable clutch member 150 which is splined to shaft 63 and serves to permit the engagement of either of the pinions 146 or 147 in operative power transmitting relation with said shaft. The movements of the clutch member 150 are controlled by a fork 151 mounted upon a slidable rod 152 extending to the exterior of housing 50, where it may be grasped for manual operation.

lhrough the provision of the motion reverser just described, it will. be obvious that shafts 63 and 64 within housing 50 may not only be connected through a variety of change speed gearing but may also be connected for rotation in opposite directions. In other words, the construction illustrated is such that shaft 64 (and the two shafts 72) and 74 connected therewith) may be connected with the table screw 13 for rotation in any desired relative directions irrespective of whether the table screw 13 or the table power shaft 14 is primarily actuated. Furthermore, through the various clutches provided in this device (to-wit, clutch members 16 and 66; 15 or 65; or the clutch member 150) suoli parts of the machanism as may be desired can be brought to rest while permitting other parts to remain active.

Note further that each set ot change speed gearing above described includes potentially operative clutch mechanism since, upon the removal ol' one ot the take-oil' gears, power transmission through the series ot' which that gear is a part must cease.

il completepower transmission train through hou-ing has now been described, and it will be remembered that this tra-in includes no less than three dill'erent series of change speed gears which have been iden titled above as Series il, Series l5, and Series C, respectively. In the Series A and Series l rate changing; devices, all of the gears are interchangeable and may be substituted each tor the other in their respective series. rllhe Series C gears, while they may obviously be made interchangeable like the others, need not be so made to satisfy the requirements ot the particular held oit usefulness above described. That is, the

olf tdci-ies C need not be interchangea ale lwithin the series. It is preferred, howwith the other.

Vi its is preferably identical with the dis tance between centers et the last mentioned pair ot sha-tts. Thus, if the arm 88 and the several gears coinlnising; Series A. are reinovecfl from the position in which such gears are illustrated, it will be obvious that gears ma and 136 may be substituted to connect shafts 85 and 86 operatively. Furthermore, the herring; member 129 ot the spider or trame 12'? is preferably provided with a hub portion 154i which is adapted to receive and rotatably sugrzport the arm 88. The web 155 wl f "ehy the bearing1 member 12S) is suppoi i in :traine 127 may also conveniently be inovided with apertures eorresponding,` to

those aiiiertures in the housing portion wl'iich receive the set screws 91 whereby the arm 88 is secured in any desired adjustment. i us the entire set ot `hfgearnnq comprising if, :i i it may be utilized not only in the position in weich it is illustrated in Figure 2, but also in substitution ttor the gearing above described as Series C.

e purpose for which the Series A and 1 t: l ,ejearinp,` is thus made bodily interchangeable may be tound in the tact that tie Series rearing is adapted 'to provide ttor a reversible niechanical advantage. ln other words, when snails G3 and Gilare terconneced 'through the train described above, either one may be made to rotate to a higher rate ot speed than the other` according as to whether the worm and worin gear comprising the Series B rate changer are disposed r '"poctively on shafts 115 and 86 or en shats 8G and 115. ln the former case the shaft G3 will obviously be the more ragliidly moving; element, whereas in the latter case shaft (hl will obviously be the more rapidly moving element. 'lhe same is true it the spiral gears are substituted l'ior the worm and worn'i gear in Series ln any event` the 2gears ot Series ll may be made to control the mechanical advantage between shafts 6Fl and lll in such a manner that either et said shafts may have advantage over the other.

lille have already described means "-.vhere by either of shafts 63 or (llt maybe primarily actuated through the device housed beneath the niacbine tool table. ln other words, it clutch pinion 27 is operative, the table screw 13 and sha'lt 63 may be driven in either direction. It the clutch device comprisiiig` sleeves 21 and 2l) is oijierative, the .screw will be stationary (except as driven through the train 'within the housing' 50) and the power shaft l-l and shaft Gil in said housingF will be primarily actuated in either direction. ln this latter event the attachment actuatingshafts 73 and Tft may also be said to be primarily actuated, since they will be driven 'l' ily 'from shaft la without the intermeon of change speed gearing. Thus, is provided within housing 50 a transncet a table atta Climent with the table screw tlu-euggh a plurality ol et change speed gearing; and in such manner that either the attachment or the screw may be driven at a higher rate of speed than the other. lt is, oilA course, preferred that the member which is operating' at the higher rate of speed shall be primarily driven, particular ly when the mechanical advantaee between the driven meinl'iers is hi `grh. Otherwise :triction losses would be excessive. and i1C an attempt were made to drive from a worin gear lo a worin the whole train inigr'ht become trictionally locked. i

'lhe reason `for making the Series A ecaring bodily exchangeable with the Series C gearing; will now be apparent. 'lhe Series A gearing, while desirable 'for the purpose of obtaining; ininte changes in mechanical advantage between 'interconnected shafts 'i3 and 63, is nevertheless inherently sturdy and much lighter than any oit the other gein:d ing housed in the removable casing 50. iliccordingly, it is preferred that the Series A gearing should always be located in the high speed end ot' the train within said housing so that the torque to be transmitted through said gearing; will be relatively small and the strain thereon will be minimized. Thus, when the spindle 1G ot the attachment is to be driven at speeds relatively greater than those of screw 13, the drive will preferably cut through clutch members 2O or 2l to the table power shaft lll, thence to the aligned shaft (34 within housing 50, thence tothe cen- :ion train potentially operative to con- 1 tral gear 7() from which the attachment actuating shafts 73 and 74 are driven, thence through the Series A gearing` which is thus located at the high speed end of the train, thence through the Series B gearing whereby the motion transmitted will be reduced in speed, thence through the Series C gearing` and the motion reverser to shaft 63 and the aligned table screw 13. Such an arrangementv is Very desirable for milling threads of small pitch.

ldlhere, however, the attachment is to be used for a spi al cutting` operation in which threads of relatively long pitch are to be produced, it may be desirable to have the table screw 13 rotate at a rate much higher than that of spindle 46. In that event the clutch members and 21 will be disposed in their neutral position as shown in Figures 1 and 2, and the clutch pinion 27 will be operated to transmit power with an initial speed reductionV to gear and to the table screw 13 which will thus be primarily actuated. Thence power is transmitted to shaft 63 within housing and through the motion ref verser to the Series A gearing substituted for Series C gearing; thence to the Series B gearing which, in the present instance, will be "just described above.

arranged as shown in Figure 8 with a worm on shaft 115 (or 115') and a worm gear on shaft 86. Thereby a reduction in rate will be effected at this'point. Unless, however, the reduction is excessive, it will be obvious that the Series C gearing need not be substituted for the Series A gearing in the manner Assuming that the Series C gearing has been exchanged with the Series A gearing, motion will now be transmitted from shaft 86 to shaft 85 and central gear 7() Athrough the Series C gears. From central gear 7 O the shafts 73 and 74 are directly driven to actuate the attachment spindle 46 which thus becomes operatively connected at the slow speed end of a train of reduction gearing in which the table screw 13 is primarily actuated and is the high speed mechanism.

` The structure and, in general, the Inode of operation of the entire device has now been described and it is thus made possible for those skilled in the art to adapt this mechanisin by the provision of suitable ratios of gears for any desired purpose. Hereinafter, however, the function of the particular ratios of gears above described will be elaborated upon in order to make clear the adaptability of this device for use in machine tool practice.

Since changes in mechanical advantage are primarily controlled in the Series B change speed gearing, or, in other words, since the greatest changes in mechanical advantage are effected at this point, it will probably be desirable to discuss first the effect of the various gears provided for use in the B Series.

Through the medium of the gears above described, other things being equal, the following ratios may be established between shafts 115 and 8G: 1/32; 1/8; 1/2; 2/1; S/l; and 32/1.

T ie gears of Series A may be arranged with 33 and 22 tool-hed gears actingas drivers, and with the 22 and 24 toothed gears z cting as driven gears, in which case they will produce a combined ratio of 33/22 32/2l-r12/l. Since this combination is also reversible, this maximum ratio may be usedv to give either of shafts S5 or 3G a mechanical advantage of 2/1 over the other. Thus, if the gears of A Series and the gears of the B Series are combined to produce their maximum or extreme ratios, it will be obvious that the relative rates of motion between shafts 35 and 115 may be 1/32X2 or 32 2/1, respectively.

The C Series of gears may either serve to transmit the above motion unchanged, providing the equally siyed gears 135 and 13G are used, or they may lower the rate in the ratio of 4 to 1 for the transmission of power in one direction. rFliese gears, in the present embodiment of our invention, effect a reduction in the rate of motion transmission in one direction only, since they have been described as being non-reversible. Thus, if all the gears of the three series are used to produce their extreme effects, it will be obvious trat the relative rate of movement between shaft 85 and screw 13 may be as high as 32 2 4 l X l -1 or may be as low as gig-j- In other words, shaft 35 may make 256 rolations to one rotation of screw 13 or may make 1/64 rotation to one rotation of the screw.

Between the two extremes above described, a vast number of intermediate speeds may be obtained. It has already been pointed out that six different ratios may be established in the Series B gearing through the substitution or interchange of gears upon shafts 115 and 86. These speeds comprise a geometrical series with a constant multiplier of four. These various speeds, when modified by the gears of C Series, still have a constant multiplier of four, since the possible effect of the C Series is merely to produce a change in the ratio of 1 to 4, and thereby to add one term to the geometrical series produced by the B Series of gears.

It is the gears of the A Series that the greatest number of changes of rate may be effected. Vilithout going into detail, it may simply be stated briefly that it is calculated that with only the above described gears o t Series A 868 different ratios may be produced between the shafts connected by these gears. lt will be obvious that these S63 possible changes will be available throughout each step of the geometrical series established by the Series B and Series C gears. Furtherin a 'very compact and convenient relationship. y

It Willbe obvious to those skilled in the art that the rate changer herein disclosed is adapted for purposes other than those Of machine tool practice. Wherever two or more members are to be operatively connected through rate changing mechanism susceptible of wide variations in relative speed, inversion of mechanical advantage or adjustment to provide minute variations 'from standard ratios, the above described device will be particularly useful. Its compactness, the ease with which it may be handled, and the accessibility of its entire mechanism, alll will recommend it. It appears, therefore, that the objects of this invention as hereinbefore specified are wholly satisfiedby the mechanism disclosed.

IVe claim:

l. In a rate changer, the combination with a pair of shafts whose aXes are relatively7 angular and in different planes, of a pair of reduction gears interchangeably mounted upon 'said shafts and adapted for operative mesh irrespective of which shaft supports any given gear, whereby said vgears are adapted y to change the relative rate of motion transmission between said shafts when interchanged.

2. In a rate changer, the combinatnm with a pair of shafts, of rate change elements comprising a worm and worm wheel each adapted to be interchangeably mounted upon v mounted upon said shafts, the gears of each pair being interchangeable and adapted to vary the relative shaft` rates when interchanged.

5. In a rate changer, the combination of a pair of shafts whose aXes are relatively angular and in different planes, and a plurality of sets of change speed gears interchangeably mountable upon said shafts in operative mesh, each set being composed of reduction gears interchangeable within the set.

6. Ina rate changer, the combination with a pair of shafts, of two pairs of rate change elements interchangeably mountable upon said shafts in operative mesh, said sets being adapted to establish differing rates of motion transmission between said shafts, and one of said sets comprising a worm and worn] wheel.

7. In a rate changer, the combination with a pair of shafts whose axes are relatively angular and in different planes, of two pairs of gears, each pair being adapted to be mounted in operative mesh upon said shafts and the gears of each pair being interchangeable within the pair, one of said pairs embodying spiral gearing.

8. In a. rate changer, the combination of a pair of shafts and a plurality of pairs of gears, each pair being adapted to be mounted upon said shafts in operative mesh, and the gears of each pair being interchangeable within the pair, one of said pairs including` a worm and worm gear and the other of said pairs including spira-l gears.

9. In ar rate changer, the combination with a pair of shafts whose axes are relatively angular and in different planes, a third shaft, variable means for effecting motion transmission between the shafts of said pair, and variable means for effecting motion transmission between one of the shafts of said pair and said third shaft.

lf). In a rate changer, the combination with three shafts, two 0f said shafts being disposed with their axes relatively angular and in different planes, of a pair of gears mutually interchangeable and adapted to mesh between one pair of said shafts, and a second pair ofgears mutually interchangeable and adapted to mesh between a second pair of said shafts.

Il. In a rate changer, the combination with a first pair of shafts and a third shaft parallel to the axis of one shaft of said pair and adapted to comprise therewith a second pair, of a worm and worm wheel interchangeably mountable upon the shafts of the first pair in operative mesh, and reduction spur gears interchangeably mountable upon the shafts of the second pair in operative mesh.

l2. In a rate changer, the combination with a pair of shafts disposed with their axes relatively angular and in different planes and a third shaft parallel to one shaft of the pair and adapted therewith to comprise a second pair, of transmission means to connectl all three of said shafts and including for each pair of shafts a plurality of sets of gears of differing ratios alternatively available for motion transmission between the shafts of each pair.

13. In a rate changer, the combination with a first shaft, a second shaft, and a third shaft, two of which are disposed with their axes relatively angular and in different planes, of a plurality of interchangeable sets of reduction gears adapted to mesh between the first and second shafts, and a plurality of interchangeable sets of reduction gears adapted to mesh between the second and third shafts, the gears of a plurality of said sets being inllt) loo

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'Lid

ally interchangeable within the terchangeable within the set, whereby to malte available a multiplicity of sneed changes between the first and third shafts.

1a. In a rate changer, the combination with a lirst shalt, olI a second shaft parallel there to, a third shalt arranged with its axis ange-- larly disposed and in a different plane with respect to the airis of the second shaft, a :tourth shaft parallel to the third shalt, variable speed Wearing; connecting,` said first and second shat s, variable speed gearing connecting said second and thii d ha ts, and variable speed gearing;l connecting said third and fourth :fil'iatts 15. In a rate ch anger, the combination with a pair et shafts arranged with their axes rciatively angular and in dillercnt planes, ot two other shafts respectively parallel to cach oit the tirst mentioned shafts, a set of reduction gearing connecting said first mentionne shafts, two sets oli reduction gearing; respectively connecting),l each ot aid other shafts with one et said iirst me rioned shaits, thc Lgears ot a plurality of said s i boina mutuset, whereby to vary the relative 'ates ot speed between the shafts interconnected,

16. rllhe combination w` u a ot tour shafts a ranged for operative gear transmission consecutively Jfrom one shaft to the other throughout said series, two oit shaits bei ing disposed with their axes at an angle and in ditlercnt planes, oit a plurality oi gear sets for each pair ot shatts in said series,

3 some et said gear sets being,1 bodily inter changeable to establish operative power transmission between their several. shatts, and the gears of a plurality et said sets being,l interchangeable within the set and comprisino; reduction gears, whereby to vary the rate of motion transmission between the shafts connected by said last mentioned set-s.

17. In a changer, the combination with a pair ot shafts whose axes are relatively anguiar and in dir'l'erent planes, ol a plurality of gears interchangeable in pairs and interchangeable upon the respective shafts potentially available for the operative connection of said shafts, said pairs of gears comprising spur gear sets an d a worm and worm gear set adapted to produce between the shatts a ries of relative speeds in an approximate geo niietrical progression.

18. In a rate changer, the combination with a pair of shafts and means operatively adapted to actuate either shaft ipniinarily, oit a worm and worm wheel .interchangeably mountable on said shafts, whereby power may be applied to the worm wheel through the worm irrespective of which shatt is primarily actuated.

19. In a rate changer, the combination with a pair oit clutch controlled shafts ea 'h selectively primarily operable by power, oit a worm and worin wheel :interchangeably mounted on said shafts, whereby the worm may always drive the worm wheel irrespective of which shaitt is primarily operated.

20. In a rate changer, the combination with a pair of shafts provided with motion trans mitting connections whereby either may be primarily actuated by power, said shafts being disposed with their axes relatively angu lar and in different planes, ot change speed mechanism potentially connecting` said shafts and adapted -for adjustment to provide for 'he operation of either shaft at a higher speed than the other,

21. In a rate changer, a power transmis sion train including change speed mechanism adjustable to provide tor speed reduction trom either end of said train to the other, and a set et' gearing bodily transposable trom a iirst position in said train to a second position in said train at the other side ot said change speed mechanism, whereby a relatively high gear speed may be maintained in said gearing irrespective of the adjustment of said mechanism.

2Q. In a rate changer, the combination of a power train enibodying' transmission elements comjliirisiig means having relatively little strength, and a pair of transposable reduction Igears productive ot relatively high speed in either end ot the train, said means being; bodily transposable between positions in either end el the train, whereby to operate at relatively high speeds irrespective et the transposition of said reduction gears.

23. In a rate changer, the combination ot a power train including at an intermediate point change speed gearing,` adapted to produce speed reductions from either end of said train to the other, and a relatively strong transmission device and a relatively less strong transmission device mutually interchangeable between positions in said train upon either side of said change speed mechanism.

24:. In a rate changer, the combination of a power train embodying a pair of transposable reduction gears, a relatively strong' set of transmission gearing, a relatively less strong set oi transmission gearin and means for supporting said sets ol transmission gearinn; interchangeably in said train upon either side of said transposable reduction gears, whereby said less strong set of transmission gearingl may be used in the high speed end of said train irrespective of the position of said transposable gears.

25. In a rate changer, the combination with a power train embodying a transposable worm and worm wheel, ot transmission elements comprising' a pair of spur gears adapted to be shifted bodily from a position. in the train upon one side of said worm and worm wheel to a position in the train at the other side et said worm and worm waeel, whereby a relatively high spur gear speed may be maintained irrespective of the relative position of the worm and worm wheel.

26. In a rate changer, the combination of a power train, gearing adapted to be shifted bodily between two spaced points in said train, andmeans for varying the relative speeds of portions of said train adjacent said points.

27. In a rate changer, the combination with a pair of shafts, of reduction gears interchangeably mounted upon said shafts for operative power transmission at a speed reduction in either direction, a third shaft, power transmitting connections including speed change mechanism connecting said third shaft with one of said first mentioned shafts, a fourth shaft, power transmitting connections between said fourth shaft and the other of said first mentioned shafts, said last mentioned power transmitting connections including a detachable `portion and said portion being interchangeable with said change v speed mechanism.

28. In a rate changer embodying a power vtrain adapted to receive power from either end, the combination in said train with a transposable worm and worm wheel, of two sets of motion transmitting mechanism mutually transposable between points in said train upon either side of said worm and worm wheel, one of said sets of motion transmitting` mechanism including a plurality of reduction gears mutually interchangeable within the set.

29. In a rate changer, the combination with two shafts crossing at right angles, of reduction gears interchangeably mounted upon said shafts in operative mesh, and two sets vof motion transmitting gearing connected in series with each of said shafts respectively, one of said sets of gearing including an adjustably supported rotor adapted to receive 'removably two of said gears and to support such gears in operative motion transmitting relation to other gears of said set.

30. A rate changing device including a housing', a pair of spaced shafts crossing at an angle within said housing,a bearing for one of said shafts provided in said housing, a third shaft supported from said housing, change speed gearing including take-off gears operatively connecting said third shaft 'with one of said first mentioned shafts, a

shaft and with its axis at right angles thereto, and a set of interchangeable gears adapted to be mounted alternatively upon said shafts in operative mesh, said gears being` accessible upon the bodily removal of said frame and second shaft from said housing.

32. In a rate changing` device` the combination with a housing, of a pair of shafts supported therefrom, a frame removably supported from said housing, a pair of shafts supported from said frame, separable motion transmitting connections between the shafts of the frame and the shafts of the housing, and motion transmitting connections between the shafts of the frame, said last mentioned shafts and connections being bodily removable with said frame from the housing.

33. A rate changing device including the combination with a housing and a pair of shafts supported therefrom, of a frame removably supported in the housing, a pair of shafts supported in said frame, separable motion transmitting connections between each of the shafts of the frame and one of the shafts ot the housing respectively, and reduction gearing potentially connecting the shafts of the frame, one of said motion transmitting con ections comprising change speed gearing adapted to be rendered accessible upon the bodily removal of said frame from the housing.

In a rate changing device, the combination with a housing, of a frame removable therefrom, reduction gearing supported from said frame and accessible exterior thereto, change speed gearing disposed interiorly of said frame within the housing, and motion transmitting connections operative to transmit power between said reduction gearing and said change speed gearing when said frame is properly positioned within the housing, said reduction gearing being bodily removable with said frame and said change speed gearing being accessible upon such removal.

In a rate changing device, the combination with a housing, of a frame member removably supported therefrom, a pair of shafts rotatably supported from said frame member and bodily removable therewith, gearing adapted to operatively connect said shafts exterior-ly of said frame member, a pair of shafts within said housing having their axes angularly disposed, and motion transmitting connections adapted to connect each of the shafts in said housing respectively with one of the shafts supported from said frame member.

3G. In a 'ate changing device, the combination with a housing, of a pair of substantially parallel shafts supported for rotation therein, a frame removably mounted in said housing, a pair of shafts in said frame substantially at right angles to the shafts of the housing, gearing connecting the shafts of the frame, mot-ion transmitting connections including reversing means between one of the shafts in the housing and one of the shafts in the frame, `said connections being separable, and motion transmitting connections including a pair of gears adapted to mesh substantially at right angles and arranged to connect operatively the other shaft in the housing with the other shaft in the frame, said gears being separable upon the withdrawal of said frame and the shafts carried thereby.

37. In a rate changer, the combination with a plurality of shafts arranged to be interconnected by gears; yof a iirst series of gears adapted for demountable association with certain of said shafts in sets and productive of a geometrical series of speed ratios between shafts so connected; a second series of gears adapted for demountable association in sets with certain of said shafts in a transmission train including said first series, the sets of said second series of gears being productive of a geometrical series of i speed ratios having a relatively small multiplier and modifying the effect of the ratios produced by the sets of the iirst series, whereby speeds intermediate the terms of said first series may be produced; and substitute 0'earing adapted for use in connection with certain gear sets of said second series, said last mentioned gearing being productive in said sets of minute variations from the terms of the second series.

38. In a rate changer, the combination with a set of gears having teeth in numbers comprising terms in an arithmetical progression; of a driving shaft adapted to receive singly certain of said gears; a driven shaft adapted to receive singly certain of said gears; an adjustable intermediate shaft adapted to support in pairs for unitary rotation certain of said gears, groups of said gears being adapted to produce a series of ratios between the driving and driven shafts comprising terms in a geometrical progression; and substitute gears adapted to be incorporated in certain of said groupsand productive of ratios varying by relatively minute quantities from the terms of said geometrical progression.

39. In a rate changer, the combination with a set of gears having teeth in numbers comprising terms in an arithmetical progression; of a driving shaft adapted to receive singly certain of said gears; a driven shaft adapted to receive singly certain of said gears; an adjustable intermediate shaft adapted to support in pairs for unitary rotation certain of said gears, whereby said gears may be mounted in groups of four including two pairs of driving and driven gears, and said groups being adapted to produce a series of ratios between the driving and driven shafts comprising terms in a geometrical progression; and a substitute gear adapted to be fitted to any et said shafts and to be incorporated in one of said pairs, said last mentioned gear having teeth in a number adapted to add or subtract minute differences in ratio to said terms according as said gear is substituted as a driving or driven gear in a group.

Ll0. In a rate changer, the combination with a set of gears having teeth in numbers com prising terms in an arithmetical progression; of a driving shaft adapted to receive singly certain of said gears; a driven shaft adapted to receive singly certain of said gears; an ad justable intermediate shaft adapted to support in pairs for unitary rotation certain of said gears, whereby said gears may be mounted in groups of four including two pairs of driving and driven gears, and said groups being adapted to produce a series of ratios between the driving and driven shafts Compris ing terms in a geometrical progression; and two substitute gears of differing numbers of teeth and ada p ted to be mounted alternatively as driving and driven gears in one of said groups to produce a differential effect of minute value, whereby to add or subtract minute diiferences in ratio to said terms, according as the substitute gear having the greater number of teeth is used as a driving or a driven gear. l

ll. .In a rate changer, the combination with shafts provided with means for their alternative actuation, of a set of gears interchangeably reversible upon said shafts, whereby to effect a possible reduction in rate to the driven .haft irrespective of which shaft is primarily actuated, said gears being in ratios of one to two, one to eight, and one to thirty-two, respectively, of a second change speed mechanism coupled with one of said shafts and in cluding a. plurality of sets of gears whose tooth numbers form the terms of an approximate arithmetical progression, the difference in terms of which is relatively small, and gears of one change speed mechanism being adapted to modify speeds produced by the other irrespective of the direction of drive therethrough, wherebv to result in a series of rate changes having relatively wide range and relatively small increments.

4t2. In a rate changing device, the combination with a first rate changer having elements alternatively available and productive of rates forming a substantially geometrical progression; of a second rate changer connected in series with said first rate changer and including a set of gears having teeth in numbers comprising terms in an arithmetical progression, a driving shaft. adapted to receive singly certain of said gears; a driven shaft adapted to receive singly certain of said gears; an adjustable intermediate shaft adapted to supportl in pairs for nnitaryrotation certain of said gears; groups of said being adapted to produce a series of ra* tios between the driving and driven shafts comprising terms in a geometrical progression, anclpsubstitute gears adapted to be incorporated in certain of said groups and productive of ratios varying by relatively minute quantities from the terms of saidgeometrical progression.

' 43. In a rate changing device, the combination with a first rate changer having ele ments alternatively available and productive otrates forming a substantially geometrical progression; oit a second rate changer connected in series with said first rate changer andincluding a set of gears having teeth in numbers comprising terms in an arithmetical progression, a driving shaft adapted to receive singly certain ot said gears, a driven shaft adapted to receive singly certain of said gears, an adjustable intermediate shaft adapted to support. in pairs for unitary rotation certain of said gears, whereby said gears may be mounted in groups of four includingV two pairs ot driving and driven gears, and said groups being adapted to produce al series ot ratios between the driving and driven shafts comprising terms in a geometrical progression, and a substitute gear adapted to be fitted to any of said shafts and to beincorporated in one of said pairs, said last mentioned gear having teeth in a number adapted to add or subtract minute differ ences in` ratio to said terms according as said gear is substituted as a driving or driven gear in a group.

" 44. In a rate changing device, the combination with a first rate changer having elements alternatively available and productive of rates forming a substantially geometrical progression; of a second rate changer connected in series with said first rate changer and including a set of gears having teeth in numbers comprising terms in an arithmetical progression, a driving shaft adapted to receive singly certain ot said gears, a driven shaft adapted to receive singly certain of said gears, an adjustable intermediate shaft adapted to support in pairs for unitary rotation certain ot said gears, whereby said gears may be mounted in groups of four including two pairs ofi' driving and driven gears, and saidV groups being adapted to produce a series oit ratios between the driving and driven shafts comprising terms in a geometrical progression, and two substitute gears of differing numbers ot teeth and adapted to be mounted alternatively as driving and driven gears in one of said groups to produce a ditlerential etlect of minute value, whereby Vto add or subtract minute dierences in raproduction ot rates in a series forming a geometrical progression, the rates produced by the gears of one set having a relatively large multiplier and the rates produced by the gears of the other set having a relatively small multiplier, said sets being connected to gether in series, whereby the output thereo't is subject to change of rate produced in both sets, together with a second rate changer in series with said output and comprising gears having teeth according to the terms of an arithmetical progression and alternatively engageable in sets productive of a relatively minute increment ot' variation from any change of rate produced by the combined geometrical progressions of said first rate changer.

EDlVAR-D J. KEARNEY. JOSEPH ARMITAGE.

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