US2149013A - Speed changing mechanism - Google Patents

Description

Feb. 28, 1939. F. A. FRITZSCH 2,149,013

SPEED CHANGING MECHANISM Filed July 22, 1937 6 Sheets-Sheet l Feb. 28, 1939. F. FRIITIZ'SCYH SPEED CHANGING MECHANISM Filed July 22, 1957 6 Sheets-Sheet Feb. 28, 1939. v F. A. FRITZSCH 2,149,013

SPEED CHANGING MECHANISM Filed July 22, 1937 6 Sheets-Sheet 5 Feb. 28, 1939. F. A. FRrrzscH ,013

SPEED CHANGING MECHANISM Filed July 22, 1937 I 6 Sheets-Sheet 5 Feb. 28, 1939. FDA. FRITZSCH SPEED CHANGING MECHANISM Filed July 22, 1957 6 Sheets-Sheet 6 mmhmfi R v X m wmw M @W QR oonnfi D S m E DT WW\\ 1 832 & 8N wn mt nnm Qw Nw% M5 M6 2 bah z 1, vmw MN. m: 3: mm Q W R w m. no. nap. 2 a v/.\ 00Q\%N-N.,

Q 0 W E 1 9 7/4 0? E l w mum M .9. N V \Rm hmm -m\v\ F wuh W .fimmw mm m mm 7 5w mum i! M um gm. RR H H M nn mm v mmm 3% R v EE? R x I W I ii-1 im UN rw F a Patented Feb. 28, 1939 UNITED STATES PATENT OFFICE 2,149,013 SPEED CHANGING MECHANISM Application July 22, 1937, Serial No. 155,072

33 Claims.

My invention relates to speed changing mechanism, suitable for lathes and other metal working machinery, and I have exemplified the same v as applied at the head end of a lathe, for example, as located in the headstock of the lathe and in association therewith.

A desideratum in the metal turning industry has for a great many years been the removal of the excess material from the work with as great a speed as possible and with as large cuts or chips as the character of the work would permit when reducing the work to approximate form, as when roughing out the work or takingrough cuts, and also when producing the finer cuts or finishing cuts on the work.

This has led to improvements in the cutting tools, originally'by hardening the steels first employed, and later by improving the steels and producing alloys of material and treating the alloys in such way as to permit of'material increase of speed between the cutting tool and the work in performing the cutting operation.

It is an object of my invention to take advantage of the improvements thus provided in the cutting tools and to provide a device in which their improved properties may-be best and most economically employed, and to provide an exceptionally heavy and compact speed transmission for rotating the work.

The latest improvement in tools is along the line of cemented tools and hardened alloys of various kinds. Experience has shown that some of these alloys designed forincreased speed in the cutting operations are themselves brittle and inclined to rapidly deteriorate, become dull or have their cutting edges break or let'down on 'account of inherent weaknesses or brittleness of the material of which they are composed.

It is a further object of my invention, therefore, to provide an improved speed changing mechanism whereby the speeds 'of operation between the work and the tool may be controlled so as to obtain the maximum life of the cutting properties of the tools combined with maximum speed of operation upon the work;

I have found, further, that it is a material advantage to let the surface speed-,between the work and the tool control the speeds of-rotation; and it is afurther object of my invention to 55 of speed throughout a material range in. speed provide novel means for accomplishing this purand to provide such steps substantially throughout the entire range, so that a given relation of surface speed between the work and the tool may be preserved, dependent on the character of material and the resistances and brittleness of 5 the tools which may be employed, having in mind further that the art of tool manufacture as to composition, cutting edge and other factors is progressive, to all of which my invention is peculiarly applicable in that it provides for varia- 1 tions in surface speed in small steps over an extremely wide range of speeds.

Exemplifying my invention as employed in lathe in which the work is rotated by a spindle, work of this nature may be of exceedingly small 15 diameter and also of great diameter, and may be of comparatively soft material or of very hard material, and include all the-gradations of diameter and material employed in this art within the capacity of the machine, and that high speed 20 cutting tools of various kinds may be employed in connection with all of these diameters and materials.

The diameter of the work and its speed of rotation determine the surface speed or cutting 5 speed between the work and the tool. Given a certain piece of work composed of a given material and a cutting tool of a given kind having a predetermined cutting edge, the surface speed between the work and the tool is dependent on 30 the resistance of the work to the cutting function and the ability of the tool to perform the cutting. Knowing these factors, the desirable surface cutting speed between the work and the tool may be ascertained, from which the speed 35 of rotation of the work may be readily calculated.

For example, assuming that it is desired to cut a piece of work of given material by means of a tool having given properties at a given surface speed, and assuming that the piece of material is one inch in diameter, a substantially high spindle speed is obtained bymy invention to produce the required surface speed between the work and the tool. Assuming, further, that with work of 45 the same material. and the same character of tool, but with the work twelve inches in diameter instead of one inch, I am enabled by my invention to obtain a spindle speed to produc'e the same or approximate surface speed, as in the last example, between the work and the tool'by decreasing the splndlespeed by means of simple mechanism, so as to reduce it to-approximately one-twelfth ofits speed in the iirstexample, in order to produce the same character oi action and speed of surface operationbetween the work and the tool.

In the first example, a spindle speed may be employed which is among the higher of the spindle speeds exemplified, and in the second example a spindle speed may be employed which is among lower ones of the spindle speeds of my improved device.

It may be assumed, further, that the tool employed in each of these instances is one of. the highest developed high speed cutting tools known at the present time, or the tool employed may be one permitting less amount of cutting speed between the work and the tool. My improved device provides simple means for producing the desired speed of rotation of the spindle in any of these examples. My improved device is, therefore, very elastic throughout a wide range of work.

The same principles of operation and characters of relation between the diameters of work, cutting tools and spindle speeds may obtain in other relations, as when performing finishing cuts between the work and the tool, in which usually different characters of tools are employed for producing a desirably high finish on the work, and in which the surface speeds be.- tween the work and the tool may vary from those of the first two examples mentioned, but my invention provides means whereby the desirable surface speeds between the work and the tool translated into desirable spindle speeds may be obtained under such different relations, dependent on the relations between the work and the tool and the desired finish.

I have found that real economy in operation is provided by delicately adjusting the speed of rotation of the work, as in a lathe, to the tool of a given character, so as to preserve the cutting edge of the tool, it being understood that these cutting edges are likely to be brittle, in order that as sustained a length of uninterrupted operation between the work and the tool, translated into length of life of cutting edge of the tool, as possible is provided, for which reason it is a further object of my invention to provide a novel speed-changing mechanism in which the speeds are closely associated over a wide range, and the steps of speed are preferably in geometric progression, so that a desired speed or a close approximation thereto may be readily obtained throughout the entire range of speed.

My invention consists in novel means foraccomplishingthe various objects stated, and in novel means for obtaining thespeeds and relations of speeds set forth; further, in a novel arrangement of gearing including shiftable elements for producing closely related speed changes over a wide range of speeds; further, in novel association of speed changing devices whereby related speed change resultants are obtained;

for moving the speed-changing elements; further, in novel means for controlling the same;

further, in novel means for avoiding interference between the same; further, in novel visual means for positioning the controls to produce the desired relations of speed-changing members; further, in a novel index portraying relations of controls for effecting speed change in association with resultant speeds; and, further, in arranging such resultant speeds in related lines or columns and cross columns having portrayals of control handles associated therewith to portray the positions of the respective handles for producing the speeds in the respective lines or columns or at the intersections of cross columns.

My invention consists, further, in novel interlocking mechanism in the speed changing mechanism between the operating devices for eflecting speed change; and, further, in novel gearing means for transmission from the spindle and novel speed-change mechanism therein, and novel means for mounting the same.

I have further exemplified my invention as employed in connection with headstock gearing in which twentyfour speeds are obtained, forward andreverse, by the employment of as little as twenty-four gears and two clutches, with the steps of speeds in regular progression in closely associated steps over a wide range and employing a geometric progression ratio preferably in a range of 1.18 to 1.29. 7

These ratios of geometric progression are given as examples, and illustrate the selectivity, versatility, minute steps and extreme range obtainable by my invention.

My invention will be further readily understood from the following description and claims, and from the drawings, in which latter:

Fig. 1 is a front elevation of the head endof a metal turning lathe having my invention applied thereto, and partly broken away.

Fig. 2 is an end elevation of the same, partly broken away.

Fig. 3 is a vertical section of myimproved device, taken on the irregular line 3--3 of Fig. 1, and partly broken away.

Fig. 4 is a rear elevation of a detail of the same, partly broken away.

Fig. 5 is a cross-section of a detail of the same, taken on the line 5-5 of Fig. 4.

Fig. 6 is a cross-section of a detail of the same, taken on the line 66 of Fig. 4.

Fig.7 is a plan view of my improved device with the cover removed, and partly broken away.

Fig. 8 is a sectional view of the gearing laid out in plane, and showing one of the power transmitting elements in neutral position in dotted lines.

Fig. 9 is a horizontal section illustrating a detail of the control mechanism, taken in the plane of the line 9-9 of Fig. 10, and partly broken away.

Fig. 10 is a vertical section of the same, taken in the plane of the line l 0-! 0 of Fig. 9, and partly broken away. I

Fig. 11 is a vertical cross-section of the same, taken in the planev of the line ll--ll of Fig. 12, and partly broken away.

Fig. 12 is a front elevation of the same, partly in section in the plane of the line I2l2 of Fig. 11, and partly broken away.

Fig. 13 is a vertical section illustrating part of the gearing, taken in the plane of the irregular line Iii-I3 of Fig. 2, and partly broken away. Fig. 14 is a cross-sectional detail view of the same, taken on the line i l-44 of Fig. 13.

Fig. 15 is a vertical cross-section of a detail of the control mechanism, taken in the plane of the line l5-!5 of Fig. 10, and partly broken away.

Fig. 16 is a front elevation of the same, partly in section in the plane of the line "5-46 of Fig. 15, and partly broken away.

Fig. 17 is a vertical section of my improved device, taken on. the line |1|1 of Fig. 1, and partly broken away; and,

Fig. 18 is a face view of the index plate for spindle speeds.

In the present exemplification of my invention there is an electric motor 2| (Figs. 1, 2, 3, 7 and 8) the rotor of which has suitable speed imparted thereto, the rotor shaft 22 having a gear 23 fast thereon, which meshes with a gear 24 fast on a drive-shaft 25, journaled in bearings 26, 21, respectively in the head end wall 28 of the headstock and in an inner cross wall 29 in the upper part of the headstock. The drive shaft is provided with clutches 3|, 32 of suitable construction, the same being shown as multiple disk clutches having a clutch operating collar 83 therebetween. The clutches are provided with suitable clutch operating levers of usual construction pivoted on a usual sleeve fixed to the drive shaft, so that upon completed movement of the clutch collar endwise in one direction one of the clutches is placed in clutching relation and upon completed endwise movement in the opposite direction the other of said clutches is placed in clutching relation, the clutchgcollar being normally in midposition for unclutched or neutral relation of both clutches.

Alternate disks of the respective clutches have usual spline connections with the usual sleeve rotating with the drive-shaft and the remaining disks thereof have usual spline connections with the shells 34, 35 of the respective clutches which are journaled on the drive-shaft or first shaft by friction reducing bearings 36, 31, and respectively have transmitting gears 38, 39 thereon. When either clutch is in clutched relation, the gear thereon rotates with the drive shaft and the gear on the other clutch is in idle relation with the drive shaft. When the clutch collar is in mid or neutral position between the clutches, both clutches are unclutched so that the drive shaft rotates idly in said shells.

A second shaft 4| is journaled in friction reducing bearings 42, 43,respectively in the head end wall 28 and the inner cross wall 29 of the head reversing gear 44 keyed to the shaft 4|.

stock, and has gears 44, 45 keyed thereto. An intermediate gear 46 is fixed to an intermediate shaft 41, journaled in bearings in said head end wall and cross wall of the main frame, and 'meshes with the gear 38 and transmits motion to the The gear 45 meshes with the gear 39. The gears 39 and 45 transmit forward rotation to the second shaft 4| when the clutch 32 isclutched and the gears 38, 46 and 44 transmit reverse rotation to the second shaft 4| when the clutch 3| is in, clutched relation.

A pair of compound gears 5|, 52 have spline connections 53 with the second shaft and are rotatable therewith and. are movable axially on compound gear 64 comprises the gears 66, 61 ar-,

ranged to be respectively meshed by the gears 54, 55, the compoundgear 65 comprises the secondary speed changing mechanism.

gears 68,. 69, arranged to be respectively meshed by the gears 56, 51, only one of the gears of the compound gears on the second shaft being at any time arranged to mesh with one of the gears of the compound gears on the third shaft. The 5 gears on the third shaft have different pitch diameters so as to properly receive different speeds of rotation from the gears of the compound gears on the second shaft, and form a primary speed changing mechanism. 1 The third shaft also has a pinion 1| keyed thereto which meshes with a gear 12 of-a combined clutch and gear element 13, which latter has thereon one of the clutch faces of a clutch 14. This combined'clutch and gear element is journaled by friction reducing bearings 15 about a fourth shaft 16, journaled in a friction reducing bearing 11 in the head end wall of the headstock and in a friction reducing bearing 18 in an inner bottom cross wall [19 of the headstock. This shaft also has thereon a combined clutch and gear element 8|, which has thereon a mating face of the clutch 14 and comprises a gear 82. This combined 'clutch and gear element 8| has spline key connection with the shaft 16, so as to rotate said last-named shaft when the coacting clutch faces of the clutch 14 are in engagement, effected by endwise movement in one direction of the combined clutch and gear element 8|. Endwise movement thereon in the opposite direction causes meshing of the gear 82 with the gear 68 of the compoundgear 65 for transmitting rota-v tion at a different speed to the fourth shaft when said gears are in meshing relation, forming a A combined gear and clutch element 81 is a part of the fourth shaft 16 and comprises a gear 88 which meshes with a gear 89 keyed to a jackshaft 90 journaled in friction reducing bearings 9|, 92, the former in the inner wall 19 and the latter in the bottdn cross wall 93 in the headstock.

A back-shaft 95 (Figs. 3, '1, 8 and 1'1) is journ'aled in a friction reducing bearing 96 in the tail end wall 91 of the headstock, in a friction reducing bearing 98 in the inner wall 93, and in a friction reducing bearing 99 in the clutch and gear element 81.

A combined clutch and gear element |0| has spline key connection on the back-shaft 95, and comprises clutch teeth I02 arranged to engage the teeth of the combined clutch and gear element 81, when the combined clutch and gear element |6| is moved to extreme position in one direction, shown as to the left in Fig. 8, the gear lines in Fig. 8, places both the clutch face and 6 gear thereof in neutral or non-transmitting position.

The back-shaft has a compound gear I01 thereabout, the gears of whichare on asleeve which has spline key connection with the-back- 7 .shafft so as to rotate therewith and be moved endwise thereon. Thiscompound gear comprises gears I68, I09 fast thereon, arranged to mesh respectively with gears 6, III of a compound gear 2 fixed to the spindle 4 of the head- 7 .l63 thereof being arranged to be meshed with keyed thereto so as to rotate therewith.

stock. When this compound gear 001 is moved to full extent in one direction, as shown in. Fig. 8, there is speed transmission in one ratio to the spindle from the back-shaft by meshing the gears i08, I I0, and when the compound gear I01 is moved to full extent in the opposite direction, the gear I00 theerof is meshed with the gear ill on the spindle, forming a quaternary speed changing mechanism.

The inner end of the spindle is journaled in friction reducing bearings M5, 5 I0 in the tail end Wall 91 of the headstock (Figs. 7 and 8), and in a friction reducing bearing M1 at its head end in the head end wall 20 of the headstock. Suitable means are provided for adjusting said bearings. The bearings M5, M0 hold the inner end of the spindle fixedly in endwise relation.

The bearing i i1 is shown as a ball bearing and comprises an inner race M8 on the spindle. One end of this inner race bears against the outer end of the hub of a gear M0, the inner end of which bears against a shoulder I20 on the spindle.

The inner end of a sleeve i2l about the reduced.

outer end of the spindle is clamped against the inner race by a nut i22 threaded about the outer end of the spindle. A sleeve I23 is slidable endwise'ln a recess I24 in the head end wall of the headstock closed by a cap 125 secured to the headstock. The last-named sleeve has a seat I26 for the outer race I21 of the bearing M1. This race is clamped in said seat between an inner flange I28 in said sleeve i120 and a closingring I28 threaded in the inner end of the wall of said seat.

A spring I30 is located in the sleeve E23 and in an inner seat I3I in the cap I25 and bears inwardly upon the inner flange I28. The sleeve I23 is movable endwise in its bearing and is urged toward a shoulder I32 on the hub of the gear, from which it is however normally spaced by an annular space I33. a

If the spindle should become heated during operation, it may expand endwise from its inner end outwardly, its inner end being held stationary endwise by its bearings I I5, I I6. Upon such expansion, the bearing N1, the sleeve I23, the pinion H9, and the parts about the outer end of the spindle will yield to such expansion, resisted by the spring I30, which maintains the parts-about the spindle in their related positions. Rotation of the sleeve I25 is prevented by a pin I34 in the frame of the headstock located in a slot I35 extending lengthwise in the outer periphery of the sleeve I23.

The compound gear H2 about the spindle is fixed to the spindle by providing the spindle with a taper portion HI, and providing the compound gear with a taper bore I42, the spindle having a threaded portion I43 at the reduced end of the taper portion. A nut I44 is threaded about said threaded portion, and is arranged to clamp upon the inner end of said compound gear, for clamping the compound gear upon the taper of the spindle. There is furthermore a key I45 in com plemental grooves respectively in the taper portion of the spindle and in said compound gear.

The spindle has the transmitting pinion H9 (Figs. 3, 8 and 13.) This pinion meshes with a pinion I48 journaled by friction reducing bearings I49 on a stationary shaft I50, the ends of which are located in the head end wall of the headstock and'the inner wall 19 thereof. The pinion I48 meshes with a gear I5I journaled by a journal bushing I52 about a transmitting shaft I63 jouraiaaoia naled by friction reducing bearings I54 in the walls of a lower extension I55 of the headstock. A reversing shaft i58 is journaled by suitable friction reducing hearings in the respective walls of said lower extension and has reversing pinions 950, it!) fixed thereon. The pinion i553 meshes with the pinion H40 and the pinion E00 meshes termediate or neutral position so that said gears will rotate loose about said shaft in opposite directions to interrupt the power feed of the carriage of the lathe, and the clutch collar may be shifted endwise on said shaft so as to connect with either of said gears to rotate said shaft respectively in opposite directions.

The clutch may be shifted by suitable means either manually, or automatically by the carriage in usual manner, manual means for this purpose being shown as comprising a fork I61'located in an annular groove I68 in the clutch collar, the fork having a bearing I69 slidable on a rod l10 fixed in the headstock. The fork is provided with a groove MI in which a shoe I12 is located. The shoe is pivoted to an operating crank journaled in a bearing I14 in the wall of the headstock and having a handle I15, the locating pin I16 whereof is insertable in holes I11 in the wall of the headstock for locating the three positions of the clutch collar. (Figs. 1, 2, 3,8 and 13.)

The shaft I53 has a pinion I8I fast thereon at its outer end at the outside of the headstock.

gear rotates with the shaft and is movable endwise thereon, being positioned in its end positions by a spring-pressed ball 202, engaging notches in said shaft. The gear 20I is provided with internal teeth 203, forming a combined clutch and gear member, these teethbeing arranged to engage the teeth of the pinion I82 to form a clutch between said pinion and saidmember.

An intermediate shaft 204 isjournaled in said walls of the gear box, and has a gear 205 and a pinion 206 fastthereon, the gear being meshed by the pinion (I82, and the pinion 206 being meshed by the gear 20I. When these ears and pinions are in meshing relation as shown in Fig. 13, transmission is from the pinion I82 to the gear 205, simultaneously rotating the pinion 206, which meshes with the gear 20I, having spline key connection with the shaft I84 for r0- tating said shaft at a lower speed, representing a regular feed for the usual feed screw 201 and usual feed rod 208 for feeding the usual carriage of the lathe. When the combined clutch and gear element MI, 203 is moved to the right so as to engage its clutch teeth with the teeth of the pinion I82, the transmission is direct from said pinion to said shaft at a higher speed, representinga coarse feed for the feed screw and feedrod,

- for example eight times the regular feed. When said clutch is in engagement, the gear 28! is out of mesh with the pinion 286, being located in the space between the pinion 286 and the gear 285, the gear 285 and the. pinion 286 then rotating idly. l

In order to move the combined clutch and gear element 28!, 283 endwise, the shaft|84 is provided witha bore 2!!, with which slots 2i2 in the wall of said bore adjacent to said combined clutch and gear element 28!, 283 communicate. A push and pull rod 2!3 is operable in said bore and is provided with an operating knob 2l4. This rod is provided with a pin 2l5, which is fast in the rod, and whose respective ends project radially in opposite directions through said slots and are located in holes '2!6 in the hub of the combined clutch and gear element 28!, 283. The pin has a threaded head 2" threaded in a threaded outer end of one of the holes2 !6. (Figs.

13 and 14.) i

The hub-22'! of a change gear 222 is keyed to the shaft I84 so as to rotate therewith. The change gear has spline connection with the hub and is arranged to he slipped endwise of! of the same for reception of a change gear of diflerent bearing 228 about the stub shaft 225. A collar 229 is suitably releasably located on the hub to hold the change gear 224 to its hub.

The quadrant 226 is arranged to be clamped in different radial positions by means of a bolt 238 in said quadrant passing through an arcuate slot 23! in the wall I89 of the gear box,- and clamped in adjusted positions by means of a nut 232'threaded over said bolt. The head of the bolt is shown flat sided and located in a slot 233 of the quadrant to prevent turning of the bolt.

The change gear 224 is arranged to be placed in proper meshing relation with a gear 234. This gear is the initial gear for the speed changing system in the feed box I94 secured in suitable manner to the bed 235 of the lathe for contro1- ling the speeds of rotation of the feed screw and the feed rod for the carriage. The outer end of the gear box l9! and the outer end of the feed box I94 are provided with a cavity 236 which extends across the joint 231 between said gear box and said feed box, and has therein the quadrant and the gears thereon and the gears with which. said latter gears mesh, the cavity being provided with a marginal flange 238. A cover 239 covers said cavity, and is provided with an oppositely inwardly extending flange 248, which forms a joint with said first-named outwardly extending flange, bolts 24! passing through holes in said cover and threaded into lugs extending inwardly from the flange 238 to hold the cover in place. The cover is provided with inwardly extending flanges 242, 243 to hold the change gears 222, 228 and their hubs in place.

The means for operating the clutch collar 33 comprise an operating lever 25! (Figs. 1,2, 3, e, and 6), secured to a square shaft 252 in a journal bushing 253 journaled in a bearing 254 in a lug 255 on the feed box. This shaft extends lengthwise of the bed to the carriage where it may be provided with a similar operating lever.

The operating lever 25! is articulated at 256 with a link 251 which has an adjustable articulation 258 with a lever 259 pivoted on a stud 268 fixed in a lug 26! extending from the headstock. The latter lever has an adjustable articulation 262 with one end of the link 263, the other end of the link being pivoted by a pivot 264 to an operating arm .265 fixed to a rock shaft 266 journaled in a bearing 261 in the headstock and having keyed thereon an operating fork 268 provided with pivoted connected shoes 269 located in the annular groove 218 of the clutch collar 33. Either clutch is engaged by endwise movement of the clutch collar, accomplished by operation of the operating handle 21! of the operating lever 25! by moving the handle upwardly about the pivot of the-operating lever for engagement of one of the clutches and moving the handle downwardly for engagement of the opposite clutch.

A spring-pressed plunger 215 is movable up and down in a bore 216 in a bracket 216' of the headstock and has oppositely tapered engaging faces 211, 218. The plunger has a slot 219 in which the end of a positioning screw 288' threaded into thewall of the bore is received. One end of the bore is threaded at 28! for having a plug 282 threaded into one end of the bore, a spring 283 having one end seated in said plug and the other end thereof received in a socket 284 in the plunger and engaging theend of the socket, the

spring operating to force the plunger outwardly.

A control arm 285 is fixed to a rock-shaft 286, journaled in a bearing 281 in the rear wall of the headstock, and in a bearing 288 bracketed from a bridge 289 mounted in the headstock (Fig. 7). The control arm has opposite contact faces 298, 29! arranged to coact with the opposite contact faces of the plunger 215, and has an arcuate riding face 292 between said faces, the curve 01' which is described from the center of the rockshaft 286. A headed pivot pin 295 is fixed in the control arm by a set screw 296. A link 291 has an eye 298 about the pivot pin between its head and the control arm. This link passes through a pivoted block 38!, having a shank 382 extending therefrom in the form of a shoulder bolt pivoted in a bearing 383 of the arm 265 and held rockingly in place by a nut 384 threaded over the threaded reduced end of said shank. A spring 385 encircles the link 291 between said block and a nut 386 threaded on said link for adjusting the tension of the spring. At the other' side of the block an adjusting nut 881 and jam nut 388 are threaded on said link to adjust the moment of operation of the control arm by means of the operating lever 25!.

The link 291 and that portion of the control arm 285 between the pivot pin 295 thereon and its rock shaft 286 form link extensions'of the,

operating arm 265, or toggle links, which are arranged to be extended or collapsed to operate the rock shaft 286.

The rock shaft 286 has a pinion 3!! thereon, (Figs. 'land 8), which meshes with a rack 3!2 on an endwise movable stem 3l3 slidable lengthwise in a stationary-bearing 3 of the headstock adjacent to the bearing288. This stem is prevented from turning by a key 3l5 located in opposite grooves in said stem and said bearing. The stem has the brake member 3!6 of a brake 3!! fixed thereon, this brake member being provided with a tapered brake lining 3l8 received in the cup member 3I9 of said brake,

, The operating means for this brake are so arranged that the brake is moved into engaged relation, so as to cause cessation of rotation of the gearing, as the clutch collar 33 is moved into neutral position, and so as to move the brake into release relation when the clutch collar 33 is moved into clutching relation for clutching of either of said clutches for either forward or reverse rotation of the headstock gearing.

The parts (Figs. 1, 2, 3, 4, 5,-6 and 8) are shown in normal relation for clutch release and brake engagement. When the operating handle 2' is moved in either direction, the operating arm 265 is either raised or depressed. When the parts are in normal relation the axes of the rockshaft 266, the pivot block I and the pivot pin 295 are in a straight line. Movement" of the operating arm 265 out of normal position either up or down moves the pivot block up or down out of such line so as to place said arm and the connecting link 29'! into angular relation, thereby decreasing the right line distance between the axes of the rock shaft 266 and the pivot pin 295,

and swinging the control arm 285 and rocking the rock shaft 285 to'operate the brake.

There is normally a slight space 320 between the pivot block 30I and the adjusting nut 301, permitting a desired idle movement between the operating arm 265 and the link 29'! to permit an initial movement of the clutch collar 33, preparatory toeifecting a transmissive engagement in the driving clutches, without affecting the brake. As soon, however, as the block 30I acts upon the adjusting nut 30'! to move the same, the link.291 is moved endwise and swung on its pivot 295 for moving the control arm 285 and releasing the brake and also depressing the plunger 215, and placing the intermediate face 292 on said control arm opposite the apex of the plunger for permitting the end of the control arm to ride upon the plunger while the control arm is moved to further extent by the operating handle to place the opposite face 290 of said control arm into line' with the opposite taper face 218 of said plunger, the plunger then moving outwardly for resiliently forcing further movement of the control arm and holding the control arm in its moved relation, whereby clutch engagement and brake release are assured.

This relation of control parts is obtained when operating the operating handle 2' in either direction for engagement in either clutch for forward or for reverse rotation of the spindle. When the operating handle is operated for release of the clutches, the control arm is again moved to the other side of the plunger and the brake is applied just in advance of release of the clutch.

The spring 305 avoids chatter of the parts and it also aids in supplementing the spring 283 to hold the brake in engaged relation, and the free space 320 permits full operation of the plunger for such engaged relation in the brake and for taking up wear in the parts.

In the speed changing mechanism four speeds are imparted to the third shaft 6| by endwise shifting of the respective compound gears on the second shaft M: (Fig. 8). These four speeds are multiplied by two by the endwise shifting of the compound clutch and gear element 8I, to engage the clutch 14, or to mesh the gears 82, 68, for imparting eight speeds to the fourth shaft I6.

These eight speeds may be transmitted direct to the back-shaft 95 by engagement of the clutch I02, in which relation the jack-shaft 90 andthe gears thereon rotate idle. 'These eight speeds may be multiplied by two by shifting the compound clutch and gear element IOI for meshing of the gears I03 and I04, in which relation the transmission to the back-shaft is through the gears 88 89, I04 and I03, resulting in sixteen speeds in the back-shaft. Sixteen speeds may thereby be transmitted to the spindle when the gear I08 of the compound gear I01 is in mesh with the gear IIO about the spindle, and sixteen additional speeds may be transmitted to the spindle by shifting the compound gear I01 for meshing of the gear I09 thereof with the gear II I fixed to the spindle, transmitting thirty-two speeds to the spindle.

In practice, however, in the present exemplification, the gears 88, 89, I04 and I03 have practically a one-to four ratio in transmitting from the fourth shaft to the back-shaft, the transmission from the back-shaft to the spindle through the gears I08, IIO, which have a one to one ratio, resulting in a given 'speed of the spindle.

This spindle speed, with the gear ratios as exemplified, is substantially the same in its various steps as the speed imparted to the spindle when the clutch I02 is in clutched relation for rotating the back-shaft at the speed of the fourth shaft and the gears I09, III are in meshing relation, the latter being at substantially a one to four ratio.

I have therefore provided control mechanism by which such duplication is avoided. By means of this'control mechanism clutching relation in the clutch I 02 with selective gear relation between the compound gear on the back-shaft and the spindle gears is employed, and the transmission through the meshing gears 88, 89, I04, I03 to the back-shaft plus the meshing of the gears I 08, H0 is eliminated resulting in twenty-four different speeds.

The full thirty-two diflerent speeds may, how ever, be obtained by changing the one to four ratio in either of the trains recited, and further spindle speeds may be obtained by adding additional pairs of mating gears having different pitch diameters between shafts, or the number of spin-- dle speeds may be decreased by eliminating selective transmission pairs. The ultimate speeds obtained may also be multiplied by employing a multi-speed motor for the initial drive.

I have provided shifting and control means for arranging the transmission elements for imparting twenty-four different speeds to the spindle, and the gear and clutch ratios are such in my improved device that the spindle speeds are arranged in substantial geometric progression from the lowest to the highest, employing a ratio factor in a range of substantially 1.18'to 1.20, the ratio factor employed in the present exemplification being approximately 1.19, that is to say, each higher speed substantially equals the next lower speed multiplied by 1.19. The resultant speeds are shown on an index plate 325 in Fig. 18, fractions in the products being disregarded. It is to be understood, however, that my invention includes any arrangement of clutch and gear elements approximating that herein shown and described, and equivalents thereof, within the scope of the appended claims, and regardless of the ratio or factor employed in obtaining resultants, or whether or not any such ratio factor be employed.

The means for changing the positions of the speed change elements and of locking the same in changed relations, where advisable, are exemplifled as including a series of levers, one of the ends of which have connections with the speed change elements for moving the latter, and the other oi the ends of which are operated by suitable handles some of which are locked in moved positions.

Thus the compound gears 5|, 52 (Figs. 3, 7, and 8), are respectively provided with annular grooves 326, 321 in which shoes 328, 329 are respectively received. Each of these shoes has a trunnion 330 rockable' in a bearing 33L These shoes are respectively at the swinging ends of levers 332, 333 respectively pivoted in bearings 334, 335 in the bridge 289, the respective ends of which respectively have support on the end walls of the headstock, being clamped in place by bolts 336. Each of these pivotal connections comprises a headed bushing 3 located inits bearing and supported by its head on the. bearing, the bushing extending below the inner end of said bearing. The lever has a. recess 342, in which the lower end of the bushing is located. A bolt 343 is located in said bushing, the head end of the bolt being supported on the head end of the bushing, and the threaded end of thebolt being threaded into the end wall of the recess 342 in the lever for clamping the lever, the bushing and the bolt together endwise, and allowing the bushing to be rockedln its bearing when the, lever is operated to shift the. compoundv gear.

A lever 345' has asimilar pivotal connection III a bearing 346 in the bridge. the swinging end of said leverbeing provided with a pivoted shoe 341. The shoe is located in an annular groove 340 in the combined clutch and gear element 8| for shifting the latter endwise.

A lever has similar pivotal connection 352 with the bridge, the swinging end of said lever being provided with a pivoted fork 353 received about the outer periphery of the gear I03 of the combined gear and clutch element ml for shifting the latter axially for engagement either in the clutch I02 or meshing of the gear' I03 with the gear I04. .The fork has pivotal connection with the swinging end of said lever similar to the pivotal connection between the shoes and the levers 332, 333 and 345.

A lever 354 (Figs. 1 and 1'7) has pivotal connection 355 with the bridge, this pivotal connection being similar to the pivotal connection between the lever 332 and said bridge. The lever :54 isprovided with a fork assist its swing ng end received about the outer periphery of the gear I08 of the compound gear I01. This fork has pivotal connection similar to the pivotal connection between the fork 353 and its lever 35!.

A series of handles is provided for operat n said levers. (Figs. 1, 2, 3, 9. 10, 15 and 16.) Thus there is a handle 359 which is fixed to a crank-shaft 360,.iournaled in a bearing 36l in the front wall of the headstock and having a crank 362 at its inner end provided with a crank pin 363 which is located in a slot 364 of an enlargement 364' of the front end of the lever 345. The relation of the parts is such that the handle may be shifted to project laterally and horizontally in either direction so that either the clutch 14. or the gear 82 of the combined clutch and gear element 8| is in power transmission relation, and when in such relation the crank pin 363 and the axisof the crank-shaft 360 are in a plane perpendicular to the pivotal axis of the lever 345, thereby placing said parts on dead centers, and thereby holding the parts in shifted relations, with the combined clutch and gear element at its endwise limits of movement, the resistance to rotation of the rock-shaft being sufllcient to lock plate hold the parts in such actuated locked positions aided bya spring-pressed ball 360' resiliently received in sockets at opposite sides of said crankshaft. A pin 358 across the slot 364 above the crankppin 36,3 compels shiftingof the'h'andle 359 in an upward arc.

There is a hollow shaft or sleeve 365 (Figs. 3, 9, 10, 15 and 16) about the reduced end of the crank-shaft 360. The sleeve 365 is journaled in a bearing 366 of a cover 361, secured to the front wall of the headstock by screws 368 for enclosing the gearing and lock plates, to be presently described. This sleeve has a segment gear 369 secured thereto, a lock plate 310 being also secured to-said sleeve, as by means of a key 3H and a set-screw 312. A hub 313 of an operating handle 314 is fixed to said sleeve, as by means of a pivot pin 315 in a notch 315' in said sleeve and located in bearings 316 at its respective ends in a shell 311 at the inner. end of said handle, and fixed in said bearings by a set screw 318 (Fig 16) This handle and shell are pivoted by said pivot pin for coaction with a locating disk 319 fixed to the bearing 366 by means of pins 380 and provided with notches 38! in which a lug 382 secured to the inner end of the shell by ascrew 383 is arranged to be received to hold the segment gear 369 and lock plate, 310 in moved positions. 1

Four of these notches are shown complementary to the four positions in which the compound gears 5|, 52 are arranged to be placed on the second shaft 4| for selective meshing with the gears on the third shaft 16. The positioning lug is normally urged into latching relation with its respective slots by a spring. 384, one end of which isreceived in a recess 385 of the hub 313, its other end bearing upon the outer wall of the in bearings 393, 394 in the front wall of the head- 4 stock and at their inner ends are provided with cranks 395,-396, provided-with crank pins 391, 398 respectively operable in slots'399, 400 of enlargements f, 402 at the forward ends of the levers 332, 333 ,respectively. The outer ends of these crankshafts are respectively provided with pinions 405, 406 and with lock plates 401; 408, the I respective pinions and'lock plates being rotatively secured to the crank shaft by keys 409, 410. The teeth of the segment gear are arranged to be brought into mesh selectively with the teeth of the pinions 405,- 406 for selectively rotating the cranks 395, 396. These teeth are shown extending throughout substantially one-half of the pitch circle of the segment 369, and are arranged to impart a substantially complete rotation to the respective pinions, 405, 406, the balance of said segment gear being recessed inwardly beyond the meshing circle of its teeth and throughout such portion being free of tooth engagement with said respective pinions. That portion of the lock plate 310 which is located in the angle extended of the free portion of the segment is extended outward- 1y radially to substantially the circle extended of theteeth of the segment, the balance of said being, recessed inwardly beyond said tooth circle.

The respective lock plates 401, 408 rotating with the respective crank-shafts 39l, 393, are

respectively provided with arcuate recesses ME, 412, extending throughout given angles of said respective lock plates 401, 408, into which the extended portion of the intermediate lock plate 310 is received when the teeth of the segment,

pass the teeth of the pinions on said respective crank-shafts forholding said respective crankshafts in operated positions until reengagement of the teeth of the segment with said respective pinions by selective positioning of the handle 314.

These angular recesses are so located that when the extended portion of the lock plate 310 is located in the angular recess of one of the lock plates 401, 408, the crank pin of the crank-shaft to which said latter lock plate is secured is in an intermediate position, for placing thecompound gear on the second shaft with which it is connected, in neutral position, as shown by the righthand compound gear 52 and the crank pin 398, respectively in Figs. 8, 9 and 10.

When either of these crank pins and the axis of its crank-shaft are in a single plane perpendicular to the axis of the pivot of the lever operated thereby, either to the right or to the left of the axis of rotation of the crank, then one of the gears of the compound gears on the second shaft is in meshing relation with its coacting gear, the parts being so constructed and arranged, however, that only one of said gears can be placed in meshing relation at any given time, during which also the other compound gear on said shaft is in neutral position.

There is a similaifiarrangement for operating the levers 35l, 354 (Figs. '7, 9, 10, 11, 12 and 1'7), except that the intermediate crank-shaft 360, its handle 359 and the operative parts connected therewith are omitted, the parts being indicated by similar reference numerals raised to the series 500. In this example the hollow shaft or sleeve 365 has a shaft 555 substituted therefor, this shaft being journaled in a bearing 566 in the front wall of the headstock. The crank pins 591, 598 are arranged to be moved into positions located in a plane perpendicular to the pivotal axes of the levers 35l, 354, in which plane the axes of their crank shafts 59L 592 are located, at opposite sides of said respective axes.

Such positions of the crank pin 591position the combined clutch and gear element I0l either in clutch engagement or in gear engagement at the respective ends of its movements, and such positions of the crank pin 598 position the comhandles may be rotated in either direction for obtaining different transmitting relations of the shiftable speed changing elements,

A cover 415 is provided for the headstock and is secured thereto by bolts 5. The cover is provided with a front angular face 411, which slants downwardly and forwardly and is presented toward the line of vision of the operator while simultaneously viewing the handles, so that the positions of the handles may be changed in connection with the observation of an index plate 325 secured to said face. Said index plate has vertical columns 4| 8, H9 in which the power transmission positions of the levers or handles 359, 314 are portrayed at 359', 314', respectively at the head ends of horizontal lines orcolumns 418', 9' of numerals stating spindle speeds. and with a horizontal line or column or columns 420,

anaemia am in which the power transmitting positions of the lever or handle 514 are portrayed at 514', re-

spectively at the head ends of vertical columns 020', 021' of numerals stating spindle speeds.

These lines or columns M8, 419', 420', Ml form cross-columns, at the intersections of which the spindle speed is shown which corresponds to the connections obtained in the speed changing mechanism by the placement of the handles in the positions portrayed at the head ends of said crossing columns. The train of power transmitting mechanism as shown in the drawings is represented as in relation for transmitting the highest speed to the spindle, namely, 500 revolutions per minute, as shown in the space at the intersection of the last of the cross columns M9, 028.

A suitable lubricant pump 425 (Figs. 7 and 8) has its casing secured to the inner wall 29 of the headstock and has an operating shaft 426, which has operative connection 421 with the drive shaft 25. A feed pipe 428 leads to said pump from a suitable sump formed by the bottom portion of the frame of the headstock and a discharge pipe 329 leads from said pump and distributes lubricant to the respective gears and bearings of the headstock and gearing herein shown and described. The height of the lubricant in the sump may be observed through a suitable window 430.

In the operation of my invention, as exemplified, adesired angular relation between the segment gear 369 and its pinions 405, 406, and the lock plate 310 and its coacting lock plates 401, 408, is shown in Figs. 9 and 10, such relation being caused by positioning the handle 314 droopingly to the left as shown in Figs. 1, 2, 3, '1, 15 and 16, and as portrayed at the bottom of column 419 in Fig. 18. The meshing relation of the segment gear 369 with the pinion 405 shows shifting connection with the compound gear and the locking relation of the lock plate 310 with the lock plate 408 shows locking of the compound gear 52 in idle relation.

When the segment gear leaves one of its pinions, the compound gear connected therewith has been placed in idle relation and the lock plate 310 simultaneously enters the angular recess in the lock plate rotating with said pinion to lock said compound gear in such idle relation until the segment gear again meshes with its pinion, whereupon the other compound gear is locked in idle position. When the teeth of the segment gear leave one of the pinions, the crank pin actuated by that pinion is in the same vertical plane in which the axis .of its crank shaft is located,

and has placed the compound gear with whichit connects in idle position.

Referring to Figs. 1, 3, 7, 8, 9, 10, and 18, the handle 359 is rotated into a position to extend to the right of its axis, as pictured in the fourth space of column 9, in which position its crank pin 363 is at the left of the axis of its crank shaft, for swinging the lever 345 to mesh the gear of the combined clutch and gear element 8| in the secondary speed changing mechanism.

Referring to Figs. 1, 7, 8, 9,10, 11, 12 and 17, the crank pin 59! is in position for clutch engagement of the combined clutch and gear element [0| and the crank pin 598 is in position for meshing of the gear I08 with the gear H0 for highest spindle speed, the handle 514 being droopingly positioned to the right as shown in Fig. 1 and portrayed in the last space in column 42l in Fig. 18. With this relation of the parts,

the segment gear 569 is in midmeshed relation with the pinion 506, and the lock plate 510 is in midlocked relation with the lock plate 501, so that when the segment gear leaves either of its meshing pinions, the crank pins operated thereby respectively are inposition for power transmission of the elements shifted thereby, In the relation of the parts stated, the lug 582 on the handle 514 is in a notch 50Ia of the locating disk 519. I

If the handle 514 be moved counter-clockwise ninety degrees, the lug 582 being placed in the notch 58lb (Fig. 12), the pinion 505 will remain stationary, being in locked condition by its lock plate, for maintenance of clutch engagement of the combined clutch and gear element IN, and the pinion 500 will have been rotated one-half revolutign, resulting in shifting of the compound gear I01 for meshing of the gear I09 with the gear III, this position of the handle being portrayed in the second space of the column 421 in Fig. 18, for transmitting ultimate spindle speeds shown'in the column therebelow in the present exemplification by different transmitting relations in the primary and secondary speed changing mechanisms.

A further rotation of the handle 514 counterclockwise ninety degrees, into the position portrayed in the first space in column 42I (Fig. 18), places the lug 582 into the notch 50Ic (Fig. 12), rotates the pinion 505 one-half revolution, pla'cing the crank pin 591 at the left of the axis of its crank shaft and-thereby shifting the combined clutch and gear element IOI for meshing of its gear I03 with the gear I04, the compound gear I01 remaining locked by the lock plates 510, 508 with'its gear I09 meshed with the gear Ill Twenty-four different speeds are thus transmitted to the spindle.

A further'rotation of the handle 514 counterclockwise throughout an angle of sixty-two degrees, places the lug 582 in the notch 58Id, and rotates the pinion 505 and the crank pin 591 accordingly, and, thereby shifts the combined clutch and gear element IOI into idle relation between the gears 88, 89 and the gear I04, as shown in dotted lines in Fig. 8, to disconnect the spindle from the primary, secondary and the major part of the tertiary speed changing mechanisms, This permits ready manual rotation of the spindle independent of the major portion of its driving train, as when adjusting work with-relation to the spindle or on a face plate which may be attached to the spindle so as to rotate therewith when fastening the work, and for other desirable setting up and adjusting purposes, or for attention to the parts.

The fourth ninety degreeangular position of the handle 514 is eliminated, as note the ab-- sence of a notch opposite the notch 58lb in the locating disk 519 in Fig. 12.

By skipping this fourth ninety degree'angular position of the handle 514, -the.simultaneous duced by the second position of the handle 514 above described in which its lug 582 is placed in the notch 58lb, as portrayed in the second space of the column 42I in Fig. 18.

My improved device presents a gear transmission which is powerful, and which provides for a wide range of speeds divided into small steps to produce a great number of speeds with a comparatively small number of speed transmission elements, the steps in the present exemplification being in geometric progression from the lowest to the highest speed and employing a factor in a rangeof substantially 1.18 to 1.20, preferably approximately 1.19, the fractions in the products being disregarded.

The index in Fig. 18 discloses that speeds from nine to five hundred revolutions per minute are obtained in twenty-four steps, as an example, providing great flexibility by my improved device.

If rotation of the spindle at a given speed, say 206 R. P. M. is desired, the numeral 206 is found on the index in Fig. 18, shown in the third space of each of the columns 8', 420'. The positions of the handles 359, 314 portrayed in the third space of the column M8, and the position of the handle 514 portrayed in the third space in the third column 420, in said index, show the directions in which said handles are to be placed on the machine to obtain the positions of speed changing elements for producing the spindlespeed of 206 R. P. M. desired.

The arrangement of the transmitting mechanism into primary, secondary, tertiary and quaternary speed changing mechanisms sequentially arranged and employed throughout the speed range, permits the use of simple and powerful shiftable speed change elements and simple shifting means for the same operable by simple handle manipulations readily observed, and placed according to the portrayals of saidhandles on a chart or index on which the selective spindle speeds are shown columnwise and cross-columnwise in relation to the handles.

Selective ones of these handles shift a plurality of shiftable speed change elements, locking selective ones of such elements in shifted relation to avoid interference between elements, and insuring that transmissions by the shiftable elements shall all be in sequence to produce the selected spindle speed.

Instancing the flexibility, convenience and economy in operation of my improved device, if an operator is rough cutting a piece of work by employment of any of the speeds shown in the columns M8, 420', and he has finished the rough cutting and desires to finish cut the piece of work,

same by simple speed changing devices which are strong, compact and readily shifted.

It is obvious that changes in the preferred embodiment of my invention herein shown and described and in the various parts thereof and their relations may be made within the. spirit of my invention as stated in the following claims.

I claim:

all he needs to do is to shift the one handle 359,

1. In gearing of the character described, the combination of a driving means, a driven member, primary speed changing mechanism, secondary speed changing mechanism, tertiary speed changing mechanism and quaternary speed changing mechanism serially arranged between said driving means and said driven member and transmitting power in the same direction through all said speed changing mechanisms for all speeds in the same direction of said driven member, two of said speed changing mechanisms transmitting duplicate series of speeds, and control means neutralizing transmission of one of said duplicate series of speeds in one of said speed changing mechanisms while maintaining such transmission of the other of said series of speeds to nullify such duplication of speeds, and constructed and arranged whereby substantial geometric progression of speeds throughout all said speed changing mechanisms is maintained.

2. In gearing of the character described, the

combination of a driving means, a driven mem-- ber, primary speed changing mechanism, secondary speed changing mechanism, tertiary speed changing mechanism and quaternary speed changing mechanism serially arranged between said driving means and said driven member, said tertiary speed changing mechanism including'direct driving connections and intermediate driving connections to said quaternary speed changing mechanism, and driving connections in said quaternary speed changing mechanism between said tertiary speed changing mechanism and said driven member being maintained to transmit power between said driving means and said driven member for all speeds of said driven member and constructed to obtain substantial geometric progression throughout said last-named speeds.

3. In gearing of the character described, the combination of a driving means, a driven member, primary speed changing mechanism, sec ondary speed changing mechanism, tertiary speed changing mechanism and quaternary speed changing mechanism serially arranged between said driving means and said driven member and transmitting power from said driving means to said driven member at twenty-four selective speeds during employment of all said speed changing mechanisms as transmitting elements for allsaid speeds.

4. In gearing of the character described, the combination of a driving means, a driven memher, primary speed changing mechanism, secondary speed changing mechanism, tertiary speed changing mechanism and quaternary speed changing mechanism serially arranged between said driving means and said driven member and transmitting power from said driving means to said driven member at selective speeds during employment of all said speed changing mechanisms as transmitting elements as so serially arranged for all said speeds, and said tertiary speed changing mechanism including two legs of power ate driven shaft while said jack shaft is in rotative connection with said intermediate driven shaft and mediately through said jack shaft throughout the speed changes of said spindle, and speed change gearing between said back shaft and said spindle to selectively impart different speeds to said spindle from said back shaft.

6. In combination, gearing of the character described comprising a driven rotatable member, a drive shaft, an intermediate driven shaft, speed changing means between said drive shaft and said intermediate driven shaft to impart different speeds of rotation to said intermediate driven shaft, a back shaft, a jack shaft, shiftable driving connections between said intermediate driven shaft, said back shaft and said jack shaft to drive said back shaft throughout all speed changes of said driven rotatable member selectively direct from said intermediate driven shaft during idle drive rotation of said jack shaft and intermediately from said intermediate driven shaft through the medium of said jack shaft to impart different speeds of rotation to said back shaft, and plurispeed gearing between said back shaft and said driven rotatable member to impart different speeds of rotation to said driven rotatable memher.

'7. In combination, gearing comprising a spindle, a drive shaft of highest speed, an intermediate driven shaft, speed changing means driven serially from said drive shaft and serially stepping down the speeds from. said drive shaft to said intermediate driven shaft, a back shaft, a jack shaft and releasable drive connecting means including gearing between said intermediate driven shaft, said jack shaft and said back shaft to drive said back shaft selectively direct from said intermediate driven shaft or immediately through said jack shaft at different speeds throughout all power transmissions to said spindle, and speed change gearing betweensaid back shaft and said spindle to selectively impart different speeds to said spindle from said back shaft, said different speeds being serial step down speeds relative to the speed of said drive shaft so related as to superpose gear reductions between said drive shaft and said spindle upon said spindle to rotate said spindle at different speeds arranged in steps which increase from their lowest to their highest speeds insubstantial geometric progression.

8. In combination, head stock gearing comprising a spindle, a drive shaft ofhighest speed, an intermediate driven shaft, two sets of speed changing means driven serially from said drive shaft and serially stepping down the speeds from said drive shaft to said intermediate driven shaft, a back shaft, a jack shaft, releasable means to operatively direct connect said back shaft with said intermediate driven shaft to drive said back shaft at substantially the speed of said intermediate driven shaft and releasable gearing between said intermediate driven shaft, said jack shaft and said back shaft to drive said back shaft from said intermediate driven shaft at reduced speed, so arranged that said back shaft and said jack shaft are rotatable throughout all speed changes, and speed change gearing between said back shaft and said spindle to selectively impart speeds to said spindle substantially equal to and less than the speed, of rotation of said back shaft,

whereby to superpose successive gear reductions between said drive shaft and said spindle upon said spindle to rotate said spindle at different speeds arranged in steps which increase from their lowest to their highest speeds in substantial geometric progression.

9. In combination, head stock gearing comprising a spindle, a drive shaft, an intermediate driven shaft, two sets of speed changing means driven serially from said drive shaft and serially changing the speeds from said drive shaft to said intermediate driven shaft, a back shaft, releasable means to operatively' directly connect said back shaft with said intermediate driven shaft to drive said back shaft at the speed of said intermediate driven shaft, and a jack shaft and releasable drive connections including gearing between said intermediate driven shaft,-said jack shaft and said back shaft to drive said back shaft, all constructed and arranged whereby from said intermediate driven shaft throughout all speed changes of said spindle, and speed change gearing between said back shaft and said spindle to selectively impart different speeds to said spindle from said back shaft throughout all speed changes, in manner to superpose said gear changes between said drive shaft and said spindle upon said spindle to rotate said spindle at different speeds.

10. In combination, head stock gearing comprising a spindle, a drive shaft, an intermediate driven shaft, two sets of speed changing means driven serially from said drive shaft and serially changing the speeds from said drive shaft to said intermediate driven shaft; a back shaft, releasable means to operatively directly connect said back shaft with said intermediate driven shaft to drivesaid back shaft at the speed of said intermediate driven shaft, and a jack shaft and releasable drive connections including gearing between said intermediate driven shaft, said jack shaft and said back shaft, to drive said back shaft' from said intermediate driven shaft throughout all speed changes of said spindle; and speed change gearing between said back shaft and said spindle to selectively impart different speedsto said spindle from said back shaft throughout all speedchanges, whereby to superpose said gear changes between said drive shaft and said spindle upon said spindle to rotate said spindle at different speeds, said different speeds arranged in steps which increase from their lowest to their highest speeds in substantial geometric progression having ratio factors in a range substantially of 1.18 to 1.20.

11. In a lathe, the combination of a rotatable spindle, speed change gearing for. rotating said spindle at selective speeds, and feed change gearing for the carriage operated by said spindle and comprising a transmitting shaft, a pinion journaled thereabout, a combined clutch and gear element rotatable with and slidable along said shaft for clutching engagement between said journaled pinion and said shaft for coarse feed transmission, and feed reducing gearing between said journaled pinion and the gear portion of said combined clutch and gear element with which said combined clutch and gear element is arranged to be meshed for ordinary transmission.

12. In a lathe, the combination of a rotatable spindle, speed change gearing for '-rotating said spindle at selective speeds, reversing gearing driven by the spindle, and feed change gearing driven in opposite directions by the reversing gearing and having. feeding connections with the mitting shaft" transmitting to said feed screw and said feed rod, a pinion journaled thereabout, a combined clutch and gear rotatively connected with and slidable lengthwise along said shaft, and spaced apart gears meshed respectively by said journaled pinion and arranged to be meshed by said combined clutch and gear element by such lengthwise sliding along said shaft in one direction to transmit lower speed to said feed screw and said feed rod, and endwise movement of said combined clutch and gear element in the opposite direction placing the clutch portion thereof in clutching relation with said journaled pinion and the gear portion thereof in idle relation between said spaced apart gears to transmit higher speed to said feed screw and said feed 'rod.

13. In a lathe, the combination of a head stock, a spindle journaled therein, feed reversing gearing in said head stock having gear connection with said spindle and provided with a transmitting gear outside said head stock, a feed box forthe feed screw and feed rod for the carriage, said feed box having a receiving gear at the outside thereof, and a gear box between said head stock and said'feed box having a feeding train therein including a coarse feed train and having gears at the respective ends thereof including 7 quadrant gearing at one of said ends arranged to be meshed with said transmitting gear and said receiving gear respectively, and means to selectively attach said gear box to said head stock and said feed box respectively for correct meshing between said gears.

14. In a lathe, the combination of a head stock, a spindle journaled therein, feed reversing gearing in said head stock having gear connection with said spindle and provided with a transmitting gear outside said head stock, a feed box for the feed screw and. feed rod for the carriage, said feed box having a receiving gear at the outside thereof, and a gear box between said head stock and. said feed box having a feeding train therein including a pinion meshing with said transmittinggear and having a clutch forming extension, a combined clutch and gear element connectible with said clutch forming extension for coarse feed transmission and reducing gears in train with said pinion and with which said combined clutch and gear element is meshed by shifting the same from said clutch forming extension for ordinary feed transmission, and quadrant gearing driven thereby and meshable with said receiving gear, and means to selectively attach said gear boxto said head stockand said feed box respectively for correct meshing between the pinion and quadrant gearing thereof with said receiving gear and said transmitting gear respectively.

15. In speed change gearing of the character described, the combination of a reversing speed change shaft, a reversing clutch shaft, a pair of friction clutches about the latter respectively having drive connections in opposite directions with said reversing speed change shaft, a clutch collar about said clutch'shaftmovable in opposite directions lengthwise of said clutch shaft for clutch connections in said respective clutches and for neutral'relation in both said clutches, a brake having operative connection with said reversing speed change shaft normally in braking position, an operatingarm for said clutch collar-normally in position of release of said clutches, and a shiftable connection between said operating arm and said brake to release said. brake upon movement of said operating arm in both of opposite whereof are'extended in sequence from said arm between said operating arm and said brake to engage said clutch and release said brake by movement in one direction of said operating arm, and to release said clutch and engage said brake by movement in the opposite direction of said operating arm.

17. In speed change gearing of the character described, the combination of a pair of friction drive clutches andspeed change gears driven thereby in opposite directions, a brake for the latter, an operating arm operable in opposite directions to clutch said respective clutches, and a multi-link operating connection the links whereof are extended in sequence from said arm between said operating arm and said brake to release said brake by movements in both directions of said operating arm, and to release said respective clutches and engage said brake by movements respectively in opposite directions of said operating arm.

18. In speed changing mechanism, a pair of shiftable power transmission elements for effecting speed change, and means for shifting said elements comprising a pair of gears respectively having operative connections with said respective elements for shifting the same, and a segment gear positioned for selective meshing relation of its teeth with the teeth of said respective gears for selective rotations of said gears to position said respective shiftable power transmission elements in selective power transmission relations.

19. In speed changing mechanism, a pair of shiftable power transmission elements for effecting speed change, and means for shifting said elements comprising a pair of gears respectively having operative connections with said respective elements for shifting the same, a segment gear positioned for selective meshing relation of its teeth with the teeth of said respective gears for selective rotations of said gears to position said respective shiftable power transmission elements in selective power transmission relations, a looking part coaxial with said segment gear in the angle extended of that'portion "of said segment gear free of transmitting teeth and rotatable with said segment gear, and a locking part coaxial with and rotatable with each of said gears, each of said last-named locking parts provided with an angular recess in which said first-named looking part is located during meshing relation of the teeth of said segment gear with the gear of said pair of gears coaxial with the other of said tions said handles must assume to obtain such respective speeds.

21. In speed changing mechanism, a shiftable 'power transmission member for effecting speed change, an angularly movable control handle for said member to control thepositions of said member by the angular positions of said handle to obtain various resultant speeds, and an index on which resultant speeds of such speed changes are shown in association with portrayals of said handle in the angular positions to effect such resultant speeds to show the positions said handle must assume to obtain such respective speeds.

22. In speed changing mechanism, shiftable power transmission members for effecting speed change, angularly movable control handles for saidmembers to control the positions thereof indicated by the angular positions of said handles, and an index on which resultant speeds of such speed changes are shown columnwise in association with portrayals of said handles in the angular positions to effect such resultant speeds. I

23. In speed changing mechanism, shiftable power transmission members for effecting speed change, angularly movable control handles for said members to control the speed transmitting positions thereof indicated by the angular positions of said handles, and an index on which resultant speeds of such speed changes are shown cross columnwise in association with portrayals of said handles in angular positions to effect such resultant speeds.

24. In speed changing mechanism, the combination of a plurality of speed changing elements for changing speeds in the same power train, and shifting means for said elements comprising a pair of handles having concentric axes, one of said handles having operative connection with one of said speed changing elements and another of said handles having operative connections with a plurality of saidspeed changing elements to change the ultimate speeds of thespeed changing mechanism, said last-named operative connections including a segment gear and an interlock part in the angle extended of that portion of said segment gear free-of transmitting teeth rotatable about said axes, and coacting gears and coacting interlock parts coacting with said segment gear and said first-named interlock part selectively at different angular positions of said segment gear and said first-named interlock part.

25. In speed changing mechanism, a plurality of shiftable power transmission elements foreffecting speed change, a plurality of rotatable operating parts for shifting said elements, a rotatable operating element having selective operative connections with said rotatable operating parts, a locking part about the latter, said rotatable operating element including a pivot member, and a handle pivoted to said pivot member and angularly movable to rotate said rotatable operating element, said handle provided with a locking part coacting with .said first-named locking part to angularly position said rotatable operating element for selective speed changes.

26. In headstock gearing, the combination of the spindle, an intermediate driven shaft having a plurality of speeds of rotation, an additional driven shaft, speed changing means between said additional driven shaft and the spindle including a shiftable speed changing member, a shiftable combined clutch and gear member and coacting parts therefor between said driven shafts to transmit a plurality of speeds to said additional driven shaft, said last-named shiftable member placeable in neutral position, a plurality of rotatable operating parts for selectively shifting said shiftable members, a rotatable operating elementhaving selective operative connections with said rotatable operating parts, and a handle angularly movable to rotate said rotatable oper-,

ating element, coactive locking parts respectively stationarily positioned about the axis of said rotatable operating element and positioned on said handle coactive in positions to locate each of said shiftable members in a plurality of speed transmitting positions and to locate said shiftable combined clutch and gear member in neutral position with relation to both of said driven shafts for severing power transmission to said spindle to enable manual rotation of said spindle.

2'7. In speed changing mechanism, the combination of a plurality of shiftable power transmission elements each shiftableinto a plurality of positions for effecting speed change, and combined means for shifting saidrespective elements so related as to hold said power transmission elements simultaneously away from one of their speed changepositions to limit the number of speed changes transmittable by said shiftable power transmission elements.

28. In speed changing mechanism, the combination of a plurality of shiftable power transmission elements each shiftable into a plurality of positions for effecting speed change, combined means for shifting said respective elements so related as to hold said power transmission elements simultaneously away from one of their speed change positions to limit the number of respective elements'for shifting the same and a segment gear positioned for selective meshing of its teeth with the. teeth of said respective gears for rotating the latter, an operating handle for said segment gear, a positioning part therefor 1 and a locating part provided with coacting parts for said positioning part angularly placed about the axis of rotation of said handle to locate said power transmission elements in selective power transmission relations and so arranged as to said elements comprising a pair of gears respectively having operative connections with said respective elements for shifting the same and a segment gearpositioned for selective meshing of its teeth with the teeth of said respective gears for rotating the latter, coacting interlocks rotatable respectively with said segment gear and said respective gears to relatethe meshing relation of said segment gear with said respective gears of said pair of gears for controlling said positions for effecting speed change and to lock said shiftable power transmission elements 'from simultaneous positioning of each of said power transmission elements in a given power transmitting position to limit the number of power transmission relations of said pair of shiftable power transmission elements.

31. In speed changing mechanism for a lathe, the combination of a spindle, friction reducing bearings at one end thereof to hold said spindle in axial direction at said end, speed change gearing fixed to said end of said spindle, a transmitiing gear on the other end of said spindle, a bearing for said spindle at its said other end, a bushing in which said last-named bearing is located, and a bearing for said bushing, said bushing movable in axial direction in said last-named bearing to compensate for lengthwise heat expansion and contraction of said spindle.

32. In speed changing mechanism for a lathe,

the combination of a spindle, friction reducing bearings at one end thereof to hold said spindle in axial direction at said end, speed change gearing fixed to said end of said spindle, a transmitting gear on the other end of said spindle, a bearing for said spindle at its said other end, a bushing in which said last-named bearing is located,

a bearing for said bushing, said bushing mov-.

able in axial direction in said last-named bearing to compensate for lengthwise heat expansion and contraction of said spindle, and a spring between said last-named bearing andsaid bushing to urge said bearing for said spindle at said other end of said spindle toward said speed change gearing. J l

33. In speed changing mechanism for a spindle, the combination of a plurality of pairs of shiftable speed changing elements arranged in sequence in the transmission, a pair of shifting means for the respective elements of each of said pair of shiftable speed changing elements respectively including a pair of crank pins for shifting said respective elements of each pair and a "pair of locking means for said crank pins of said respective pairs, said locking means for each pair of crank pins locking one of the crank pins when releasing the other of the crank pins of said pair of crank pins, and so constructed that said looking means for one of said pair of crank pins locks the elements of the pair of shiftable speed changing elements operated thereby selectively in idlerelation, and said locking means for the other of said pair. of crank pins locks the elements of the pair of shiftable speed changing elements operated thereby selectively in transmission relation.

FRANK A. FRITZSCH.

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