US1814078A

US1814078A - Machine for boring cylinders

Info

Publication number: US1814078A
Application number: US425385A
Authority: US
Inventors: Charles B Cole; Lewis Otto Leroy
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-02-03
Filing date: 1930-02-03
Publication date: 1931-07-14
Anticipated expiration: 1948-07-14

Description

July 14, 1931. c. B. COLE ET Al.v y 1,814,078l

IACHINE FOR BORING CYLINDERS Filed Feb. s. 1930 s sheets-sheet 1 AE-l July 14, 1931. c. B. COLE E-'r AL 1,814,078

` MACHINE-Fon BORINGy CYLINDERS Filed Feb. 5. i930 s sheets-sneer 2 lllwlfllfff/lluw/mmll um i dll lll July 14, 1931. c. B. coLE ET AL MACHINE FOR BORING cYLINDEns Filed Feb. 3. 1930 3 Sheets-Sheet 3 Patented July 14, 1931 UNITED STATES PATENT oFElcE` CIIABLES B. COLE AND OTTO LEROY LEWIS, Fl CHICAGO, ILLINOIS I MACHINE FOR BORING CYLINDERS Application led February 3, 1930. Serial No. 425,385.

the internal diameter of the same, and morel particularly to the portable type of such mai chines, commonly used for reboring operations. This invention is ynot limited to the portable type, however, as it is also applicable to stationary machines both verticalv and horizontal.

Portable machines as at present constructed require a long and tedious set up; involving the changing ofpulleys and pickof gears to obtain the necessary speeds and feeds, the clamping of the machine in operat- 15 ing position without adequate means forcentering and aligning the bar, and the installation of a power unit for driving.

One ofthe objects of this invention is to decrease set up and operating time by mak- 2 ing the outfitA self contained, easily centered and installed, and convenient to operate.

Another object is to provide suitable lubrication and exclude the dust from the worklng parts.

Another object is to provide a machine easily handled by a crane, the operating levers being disposed so' as to avoid ytheir being knocked oil or damaged by striking objects while-the machine is being handled by the crane.

A still further object is to provide a machine which may be used for either boring or grinding the internal diameter of the cyl-y inder simultaneously or consecutively, securing greater accuracy than at present usually obtamed.`

These objects we obtain by the means and mechanism illustrated in the accompanying drawings, showing a preferred construction; these drawin forminga part of this speciication, in w ch- Figure 1 is an elevation giving a general view of the machine as set up for boring a cylinder, the cylinder being shown in section;

Fig. 2 is an end view of the out-board support for the boring bar;

Fig. 3 is a sectional view'of the same, the section being taken on the vertical center lin -through Fig. 2;

5. Fig. 4 is an end view of any one of the vertical ling devices; and

several supporting brackets used to attach the machine to the cylinder; A

Fig. 5 is a view partly in section showing the jack for supporting the overhanging end of the machine;

Fig. 6 isa sectional View of the body of the machine, includin the transmission and the centering device, t e section being taken in a planel through the axis of the boring bar;

Fig. 7 being a projection of one supporting arm shown in Fig. 6 showing the form of the end of the supporting arm;

Fig. 8 is a sectional view showing the relation between the various gears, clutches and shifting members, the section being taken on a line through the axes of the shafts shown;

Fig. 9' shows the general formi of the sliding gear shifting forks; j

Fig. 10 is a sectional viewV ofgthe body of the machine, including the transmission, centering device and boring bar, the section be- 'ing taken in a horizontal planethrough the axis of the borin bar;

Fig. 11 is a sectlonal view of one of the feed gears, showing ,the ball drive construction;

Fi 12, partly in section, shows the genxral( orm of the worm wheel clutch throwout Fig. 13 isa sectional view showing the interlock between the feed change control shaft and the rapid traverse control shaft;

Fig. ,14f. isa plan view and Fig. 15 isa sectional view showing the general construction of thefeed 'change and speed change control- Fig. 16 is a sectional view of the position retaining device for the rapid traverse shifter and the worm wheel clutch throwout.

Referring to the drawings in detail, and first, to Figurel, the construction shown comprises a boring bar 1 driven and supported at one end bythe transmission 2, power being furnished the`transmission from the motor 3 attached to the transmiion case, the motor driving the transmiion through a chain enclosed in chain housing 4. The transmis- `sion is supported at one end by a jack 5.

The other end of the transmission is supported by brackets 6 which are bolted to one end of a cylinder 7 which is to be bored, the other ends of the brackets being arranged to grip the arms 8 extending from the transmission case. Similar brackets 9 attached to the other end of the cylinder 7 support the outboard bearing 10 for the boring bar 1. The boring bar carries a boring head 11 on which are mounted a boring tool 12 and a grinder 13, this combination being described in our co-pending application, Serial No. 425,386, iiled February 3, 1930, entitled Tool Carrying Head. The power (which may be compressed air) is. furnished the grinder (which may include an air motor) through flexible coupling 14 and a connection 15 which passes from the grinder through a hole 15a in the boring bar to the coupling 14. The levers at the top of the transmission have the following functions: a lever 16 (of which there are two, one mounted behind the other), speed change; a

lever 17, hand rotation of the boring bar; a'

lever 18, feed change; a lever 19, worm wheel clutch throwout; a lever 20, rapid traverse control by power. The lever 17 is detachable and'when applied to the Squared end of a shaft 21 it may be used to operate the rapid traverse by hand.

Referring to Figs. 2, 3 and 4, the boring bar 1 is slidably supported in a bearing bushing 22 which has a spherical seat in the bearing

bushing retainers

23 and 24, this spherical seat permitting the bearings to line up properly with the bar. The

bearing retainers

23 and 24 are adjusted, if necessary, by shimining under the shoulders so that the bearing bushing spherical seat is a free running t in the retainers. At the ends, the bearing bushing clears the retainers suiciently to permit the bearing bushing to rock slightly on its spherical seat. The bearing bushing 22 isslotted to receive a key 25 pivoted on a pin 26 and depressed by a spring 27 into the keyway in the boring bar 1, driving the bearing bushing in unison with the boring bar. This arrangement permits the boring bar to enter the bearing bushing regardless of the relative'positions of the key and keyway, the key snapping into place when the bar has rotated sufficiently to bring the key way in line with the key. The bearin retainers 23 and47 24 are' firmly clampe against the shoulders in an adjusting ring 28 by screws 29, shims being placed under the shoulders, if necessary, to adjust the spherical bearing, as previously explained. The

' adjusting ring,28 is radially adjustable in an outboard bearing housin 30 by means of screws 31 operated by a and knob 32 and after adjusting locked by a nut 33. The inner ends of the screws 31 are rounded and supported in the housing 30 so as to bear against the tapered face of a collar forming a part of theadjusting ring 28, the other face of the collar being flat and seating against a shoulder in the bore of the housing 30. Pressure from the screw tends not only to move the adjusting ring 28 radially, but also to keep it tight against the shoulder in the bore of the support 30, securing rigidity. The protruding arms of the housing 30 are machined to receive the supporting brackets 9 which may be clamped on the arms by means of screws 34 after installation on the cylinder; the angular spacing between the arms tending to centralize the bearing bushing with the cylinder, final Vadjustment being made by the shifting ring 28 by means of the screws 31.

Referring to Fig. 5, a tubing 35 is slidably mounted in the jack base, being retained in position by a screw 37 threaded in a base 36 and having a tapered endI to engage one o a series of tapered holes in the tubing 35, thereby securing rough vertical adjustment. The ring end of the screw 37 provides means for attaching a lifting hook as well as forming a socket for a bar or wrench to tighten the screw. For iine vertical adjustment, a screw 38 is threaded into a nut 39, which is provided with slotted ears and a clampbolt :for tightening the nut on the screw, this clamping construction being the same as shown in Fig. 4. The lower end of the nut 39 is a free iit in the tubing 35. 'A shoulder on the nut 39 bears against the end o the tubing 35. The nut is provided with cross holes for inserting a bar to turn it. The jack is attached to transmission 2 by means o a cross pin 40.

Referring to 6, 7, 8 and 9, the mechanism for driving and feeding the boring bar 1 is encased in a housing consisting of a center piece 41, a rear end plate 42 and a front end plate 43. The front end plate 43 is I{lili-Ipvided with protruding arms for attac g the supporting brackets 6, as shown in Figure 1. These arms are machined, as shown in Fig. 7, to receive the universal chuck aws 44 operated by a scroll 45 supported in the end plate 43 and retained in the same by a plate 46 which is bolted to the end plate 43 by screws 47. The scroll is operated by turning the bevel pinions 48 havmg sockets to receive a wrench, the pinions engaging gear teeth cut on the back of the scroll. The pinions 48 are retained in position'by a key 49 retained by a screw 50. The arrangement of the pinion and the scroll is standard chuck construction and is not claimed as novel.

' The chuck jaws 44 are provided with L-shaped slots for retaining the slip jaws 51 at various radial positions, so that a limited movement of the chuck jaws 44 will take care of a large range of chucking diameter; the distance between the L-shaped` :slotsfbeing somewhat less than the allowablev travelof the chuck jaws 44. The slip jaws 51- may be locked in place on the jaws 44 by tightening the screws 52, the tapered points of which l dial position somewhat less than the diameter of the cylinder to be bored. After the transmission has been lightly clamped in position on the cylinder by means of the support y brackets 6, the 'ack 5 being adjusted to take the weight of t e other end of the transmission, the scroll of the chuck is rotated by' the pinions 48, moving ogitward the chuc jaws 44 carrying the slip jaws 51 until the slip jaws 51 engage the inner diameter of thel cylinder, thereby centering the transmission and the boring bar with the cylinder. The supports 6 are then rigidl clamped to the c llinder and -tothe arms o the end plate 43,'

t e jack 5 finally adjusted to support the Weight of the rear end, the jack screw locked to secure rigidity, the screw 52 loosened and the chuck jaws 44 run in far enough so that the slip jaws 51 may removed. The slip jaws 51 are then removed to provide clearance for the boringhead 11, Figure 1.

The boring bar 1 is supported in the transmission case by a driving sleeve 54. One end of this sleeve is supported inbearing bushings 55 and 56 pressed into thehousing 41. A bevel gear 57 is pressed on Vthe other end of the-sleeve54 and secured by a nut 58. The hubk of the bevel gear 57 takes a bearin in a bushing 59 pressed in a plate 60, the

late- 60 being secured to the end plate 42 y screws 61. The outer diameter of the plate l60 fits a counterbore in the end late 42 and it also fits a bore in the'end o the housing 41, centralizing the housing 41 with the end plate 42. The sleeve 54 acts as a driver for the boring bar 1, driving through a key 62 which is a sliding fit in the keyway in the boring bar 1 and is securely fastened in the sleeve 54. The sleeve 54 is driven from a worm wheel 63 bolted to a worm wheel hub 64 through a ball drive shown in Fig. 10,

the drive between the worm wheel hub 64 and gears 7 2V and 7 3,v the gears being spaced fromthe bearings by spacing collars 74; the gear spacing collar and the inner bearing race at each end of the shaft being 'clamped against a shoulder on the shaft by a washer 75 tightened by screws 76.

The gears 72 and 73 are driven from the

gears

77 and 78, respectively, mounted in slidable driving relation on a lpower shaft 79 which is supported by anti-friction bear ings 80 in bearing retainers 81 mounted in the transmission housing 41. At one end of the shaft a dust excluding and grease retaining packing 82 is held in place by a packing nut 83, this end of the shaft belng exposed and arranged for attaching the sprocket 154, Fig. 10, driven by the chain from the motor mounted under the transmission case and attached to it by studs 84. The other end of the power shaft is covered by a cap 85, the cap 85 and the plug 83 being interchangeable so that the drive may be taken from either end of the shaft.

The sliding gears 77 and 78 are shifted into -operating position by the shifting forks 86 and y87, respectively, the general form of vthese 'forks' being shown in Fig. 9. The

forks are firmly fastened to the

rods

88 and 89 by the nuts 90. The rods are'supported in a lug projecting from the plate which is drilled to' hold an interlocking ball 91 between the rods in such a relation that the ball must enter the countersink on one rod, locking it in neutral position, before the other rod'can be shifted to engage a gear. The shifting rod`89`isactuated by apinion 92 engaging a rack; the pinion/ 92 forming the lower extremity of a shifting rod 93, the construction of the upper end of which is shown by Fig. 15. The shifting rod 88 is actuated by a similar rod and pinion. The sliding g gears 77 and 78 and the gears 72 and 73 are double gears, the ratio between each set of gears varying so that four different speeds of the worm shaftare obtainablei p The boring bar 1 may be,rotated b hand by turning wrench 69 engaging inriving relation ,one end of a shaft 94 tol the other end of which is securely fastened a pinion 95 engaging the bevel ear 57. The shaft 94 is -supported by a aring bushing 96 mounted in the transmission housing 41, the

bearing bushing 96 covering a large inspec tion hole in transmission housing 4 1. A plug 97 serves as a lifting ring and oil filler cap.

The boring bar 1 is fed longitudinally by a rotating nut 98 threaded on the boring bar, this nut eing limited for end movement by a thrust washer 99 at one end bearing against bears against the sleeve 54 supported endwise by the bushing 55. The

gears

100, 101

y the-plate 46 and at the other end the nut 98 gear being pressed against the friction washer by a spring 108 retained by a washer 109 secured endwise by a locking Wire 110. The friction drive lessens the shock of sudden engagement. The bevel gears 111 and 112 are rotatably mounted on the shaft 106. Either of these gears may be engaged in driving relation with the shaft 106 by the shifting

collars

113 and 114 so as to depress balls 115 into countersinks in the shaft 106, the balls being located in holes in the hubs of the bevel gears. As

collars

113 and 114 are operated by the same shifter 116, one gear will not be engaged until the other has been disengaged. T'hese bevel gears mesh with the v lbea/el pinion on the end of the shaft 117 -on which shaft is mounted in driving relation a spur gear 118 secured by a nut 119. The gear 118 engages the gear 102 on the nut 98. The direction of rotation of the nut, and

therefore the direction of longitudinal movement of the boring bar 1, will therefore depend upon Whether gear 111 or the gear 112 engages the 4shaft 106 in driving relation.

The shaft 117 is supported at the pinion end by a bearing bushing 120 pressed in the transmission housing 41, and at the other end by a bearing bushing 121 pressed in the plate 46. The shaft 106 is supported in bearing bushings 122 'and 123 secured in the housing 41 by set screws`12/4. The ends of these bushings are cupped to' receive packing washers 125 which are retained by collars 126 threaded on the ends of the bushings 122 and 123. These collars also form a guard for the squared ends of the shaft 106, the ends being squared so that a wrench may be applied for operating the rapid traverse by hand. The gears 111 and 112 are spaced by a collar 127 pinned on the shaft 106. The shifter 116 slides on a. shifter shaft 128 which is secured 1n the housing 41 by screws 129. .The shifter 116 is operated by a pinion 130 forming the lower extremity of a shaft 131 shown in section in Fig. 10.

Referring to Figs. 10 to 16 inclusive, a rapid traverse control lever 132 having a limlted vertical movement on a pin 133 is used to impart rotary motion to a shaft 131 through a lever support 134 firmly secured to the shaft 131 by a pin 1315. The lever support 134 is free to turn in a bushing 136, which is securely locked in the transmission housing 41 by a screw 137. The bushing 136 h asa notched rim, the notches being used to retain the lever 132 in the desired position. The lever 132 is depressed into the notches .by a plunger 138. actuated by a spring 139.

The boring bar 1 is given a slow longitudinal movement by rotating the nut 98, this rotation being accomplished by means of the follow-ing described differential gearing. A gear 140 'forms the end of the driving sleeve -54and meshes v vith a pinion 141 integral with a pinionV shaft 142 supported in a bearing bushing 143 in the transmission housing 41 and by a bearing bushing 144 pressed into the end plate 43. The

pinions

145, 146 and 147 are free to rotate on a shaft 142 in the position shown; but should the plunger 148 be moved to the left, the enlarged portion of the plunger 148 would push the balls 149 into recesses in the pinion 146, engaging in driving relation the shaft 142 and the pinion 146. This ball drive arrangement is clearly shown in Fig. 11; A'further movement of the plunger 148 to the left will engage the pinion 145 and release the pinion 146, while moving the plunger 148 to the extreme right will engage the pinion 147, the

pinions

145 and 146 being released. The action is as follows: The gear 140 constantly drives` the shaft 142 through the pinion 141. When disengaged, the

pinions

145, 146 and 147 revolve idly on the shaft 142, the nut 98 revolving in unison with the boring bar 1. If one of the

pinions

145, 146 or 147 is engaged with driving pinion and its mating gear on the nut. Various feeds may therefore be obtained by using gears of different ratios, the combination shown giving three feeds.

The plunger 148 is operated bya pinion 150 engaging a rack on the plunger and forming the lower extremity of a feed control shaft 151, shown in Fig. 6. The shaft 151 is imparted rotary motion by a hand vlever 152, Fig. 6,.the mechanism being identical with that shown in Figs. 14 and 15 and previously described. The feed control shaft 151 is interlocked with the rapid traverse control shaft 131, Fig. 13, by an interlocking rod 153, the shafts being countersunk to engage when in neutral position the ends of the rod 153, the length of which is such that when one shaft has been rotated, the other is locked in neutral position, making it impossible to engage the rapid traverse and the slow feed at theA same time. The rod 153 is supported by lugs forming a part o"f the housing 41.

In Fig. 10, the outboard portion of the boring bar 1 is shown in section `to disclose the holes drilled and tapped in the bar for installing the connections for transmitting power to the grinder mounted on the bar, as shown in Figure 1.-

The drive chain for the sprocket 154 on the power shaft 79 is guarded by the chain housing 4, supported by the transmission housing, as shown 1n Figure 1.

gear 63 is engaged in driving The worm relation with the driving sleeve 54 by the balls 155 being depressed into countersinks in the sleeve 54 by shifting the collar 65 which is shown in Fig. 12. The shiften fork is` keyed and bolted to a shifter shaft 156, which is supported by a bearing bushing 157 secured in the housing 41by a screw 158. A collar 159 retained on the shaft 156 by a cross pin 160 is provided with countersinks on its lower surface to engage aball 161 operated by a spring 162 to hold the shifter 66 in engaged and disengaged positions. The upper end of the shaft 156 is squared toreceive the lever 19, Figure 1.

'I'he shifter fork .66 may bethrown to a disengaged position by a plunger 163 supported in a plunger barrel 164, pressure between the barrel and the plunger being maintained by a spring 165; the plunger being retained by a cross pin 166 operating in the slots in the barrel 164. A swinging lever 167 hinged by a pin 168 passing'through lugs in the plate may be pushed against the bar- ,rel 164 by a pin 170 or by a collar 171 secured to the boring bar 1 by a pin 172. The pin 170 may be pushed endwise by a lever 173 pivoted on a pin 174-supported by lugs projecting from 'an end cover 175 secured to the end plate 42 by screws 176. The action of this mechanism is as follows:

Referring to Fig. 10, should the boring bar 1 be fed as far as it should go to the left, the end of the bar will ress against the lever 173, which, being pivoted on the pin 174,

will push the pin 170 to the right. The end of the pin 17 0, pushing against the swinging lever 167, will cause the lever 167 to move the barrel 164 to the right, compressing the spring 165, which' will move the plunger 163 to the right; which bearing against a projecting lug on the shifter lfork 66, causes the shifter fork 66 to shift the worm wheel clutch throughout the collar "65 to the left, thereby disengaging the worm wheel hub 64 from the drivin sleeve 54, stopping the feed and rota-- tion o the bar. In order to .feed the bar forward, the rapid traverse lever 20 is set in forward feeding position, and the worm gear clutch control lever 19, Figure 1, is swung into engaging position, the spring 165 compressing to allow this movement. Should the ar 1 be fed toits extreme right position, the collar 174 will engage the swin ing lever 167, which operating through the barrel 164,

lthe spring 165, the plunger '163, the shift fork 66 and the collar 65 will disengage the worm wheel, thereby stopping feed and rotation of the bar.- y

The above mechanism prevents damage to the machine by feeding the bar too far in either direction. j

We realize that considerable variation from the above construction may be made without departing `from .the spirit of our-invention,

andgtherefore, we desire that our invention shallnotlbe .limited tothe details shown. In

particular, we,=mention the addition of oil 2carrying hea holes and'oil grooves, the substitution of antifriction bearings for plain bearings, or vice versa, the addition of an anti-friction lining the transmission end in the outboard bearing 10 in place of the hand screw adjustment shown; the bearing bushing 22 and the bearing

bushings

23 and 24 being installed in the chuck body instead of the adjusting ring 28.

Likewise, the centering device shown in Fi 3 could be applied to the transmission en instead of the sjcroll chuck. i

We claim:

1. A machine for grinding cylinders includinga bar capable of rotary and lon itudinal motion, an enclosed transmission or imparting rotary and longitudinal motion to the bar, means for installing the transmission and bar in operating position, means for supporting the outboard end of the bar, a head mounted on the bar for supporting the grinder in operating position, and a grinder, driven by power transmitted through the bar from an outside source. l

2. A machine for boring and grinding cylinders, including a bar capable of rotary and longitudinal motion, an enclosed transmission case for imparting rotary and longitudinal movement to the bar, means for installing the transmission and bar in operating position, means for supporting the outboard end'of the bar, a driving head mounted on the bar and carrying a boring tool and a grinder adjustably mounted for boring and grinding the cylinder individually or simultaneously, the grinder being drivenby fluid pressure transmitted through the bar.

3. A boring and grinding machine of the character described, in combination with a supporting member consistingof a base, a member telescoping'with the base, means for locking in fixed relation the base and teleclosing the mechanism for imparting motion to the bar, and carrying a plurality of projecting arms, brackets for rigidly attaching the transmissionby means of the arms to the cylinder to be bored, means for clamp-ing the brackets to the arms, an outboard bearing for the bar having a plurality lof projecting arms, means for attaching the arms to the c linder to be bored, and a toold7 mounted on the bar.'-

5. .A cylinder boring and grinding machine of the character described, including .45 housing for radially L 50 chine of the character movement, a transmission case enclosing the mechanism for imparting motion to the bar, means for attaching 1n operating posi? tion the transmission to one end of the cylinder to be bored, an outboard support for the bar including a bearing having means for aligning itself with the bar, means for revolving the" bearing in unison with the bar, means for adjusting the bearing fit, means for centralizing the bearing with the supporting arms and with lthe cylinder to be bored, means for attaching in operating position the outboard bearin to one end of the cylinder to be bored, an a tool-carrying head mounted ,on the bar.

7. In a cylinderboring and grinding ma-4 chine of the character described, an outboard support comprising a bearing bushing .provided with a pivoted key for enga) ing the boring bar, slidably fitting the ing bar and having a partly spherical outer diameter seated betwen two .adjustable retaining collars mounted in an annular member capable of limited radial adjustment in a housing having .raidal arms carrying brackets for attaching the housing to the cylinder to be bored; the annular member having a flat shoulder to bear against a flat shoulder in the housing, and a tapered 'shoulder against which pressure is brought by means of screws within the arms of the addjlusting the annular member, means for ra 'ally adjusting the annular member, and means for locking it in place. Y

8. In a cylinder borin and grindingmaescribed, a centerling and holding device including a plurality of varms projecting from the transmission case, means for centering the boring bar with the cylinder by mechanism within the arms, an outboard support having a plurality of projecting arms, means Afor attach# ing the arms to the cylinder and means for centralizing the bar with the cylinder by mechanism within the arms.

9. In a cylinder boring and inding machine o'f the character describer a centralizing device consisting of a plurality of arms projecting from the p ortion of the housin surrounding the bar, a pinion driven chuc 6.5 scroll retained within the housing concentric with the bar, chuck jaws engaging the scroll and slidably mounted in the projecting arms, retaining slots in the outer face of the chuck jaws concentrically spaced with the boring bar, slip jaws for gripping the bore of the cylinder retained in the slots by a plunger depressed in a groove in the upper face of the sliding jaws, means or depressing the plunger.

10. In aA cylinder boring and grinding machine of the character described, a supporting case, a transmission enclosed in said supportingcase, a boring bar, means for selectively rotating the bar at desired speeds by hand and power, means for selectively feeding the bar longitudinally by hand and power, means for rapidly traversing the bar by hand and power, means for interlockin the speed control mechanisms and the feed control mechanisms, and means for automatically stopping feed and rotation of the bar at its eXtreme forward and reverse positions.

11. In 'a cylinder boring and grinding machine of the character described, a borin `bar splined for drivin rotarily and threaded for feeding longitu `na]ly, a sleeve surrounding said bar and having a driving key engaging the spline in the bar in sliding drivmg relation,` bearingsffor supporting the sleeve within the transmission housing, a worm gear mounted on the'sleeve to rotate 'freely on the same, means for engaging and disengaging the worm wheel and sleeve in driving relation, means for driving the worm wheel at a plurality of speeds, a gear on one end of the sleeve engaging a pinion on, a countershaft supported by bearings in the transmission case housing, a pluralit of gears rotatably mounted on the counters aft, means for engaging and disengaging the gears with the countershaft, a nut threaded on the boring bar, supported against endwise movement and carrying in ixed relation gears to mesh with the several gears on the countershaft, this gearing constituting a diferential feed for the boring bar, a bevel supporting the bar, engaging a beve pinion havin means for hand operation, a worm shaft aving a threaded worm engaging the worm wheel, a lurality of fixe speed change gears, and earings retained and supported in the transmission housin a powerdriven sliding gear shaft, sli g gears gear rigidly mounted on the driving ing gears on worm shaft, means for shifting sliding gears and locking them in position, a rapid traverse gear supporting shaft in bearmgsin the transmission housing for said rapid traverse shaft, a driving hub ixedly mounted on 'said shaft, a friction member driving said hub, a gear for driving said friction member mounted rotatably on the hub and engaging one of the speed sleeve mounted on sald shaft to engage correspond- 'nut on the gears on the worm shaft, means for main- 4traverse shaft, means for engaging either of these gears in driving relation with said shaft, a pinion engaging both bevel gears from which 'it receives clockwise or anti-l clockwise motion depending upon which is the driver, a sha integral with the pinion, supported in bearings'in the transmission housing and carrying a gear in driving relation meshing with one Pof the gears on the orinfg bar, and a transmission case consisting o a central member having suitable ribs for supporting bearings, an end member ,enclosing the centralizing'device and carrying the supporting arms, an end meinberforming the housing for the screw endbf the bar and supporting a part of the automatic stop mechanism and a follower plate centralizing said member with the center member and supporting one sleeve bearing and the speed gear shifting rods, and means Afor automatically stopping the traverse-,ofthe bar at its extreme forward and reverse positions.

12. Ina. machine for boring and grinding cylinders, of the character described,.a mechanism for automaticall stopping the bar at its'extreme forward andI reverse positions, includin a pivoted lever, one end of which engages te end of the bar at its eXtreme reverse position-` the other end of the lever engaging a push pin bearing against a. 'swinging inember imparting motion to a plunger supported in the follower plate of the transmission and through the plunger imparting motion to a mechanism disengaging the worm wheel from the driving sleeve, thereby stopping all motion of the bar, a collar firmly fastened-on the bar engaging at the extreme forward position of the bar the swinging' member, pressing it againstthe plunger and thereby imparting motion 'to the mechanism disengaging the' worm wheel, thereby stopping the bar, said plunger including two telescoping members, a cross pin iirml fixed in one member and engagin slots with closed ends in the other so that t e members have'- a limited travel rearding each other, and a spring interposed tween the two members to maintain pressure between the saine. 13. In a cylinder boring and grinding machine of the character described, a power driven worm shaft supported in a transmission case by bearings taking thrust and radial load, a worin wheel mounted concentric with a boring bar and rotating freely uponl a sleeve surrounding the boring bar, a collar mounted u on the hub of the worm wheel and free to shde a'limited distance upon the same, a plurality f balls retained in holes in the hub of the worm wheel and by the collar, countersinks in the sleeve surrounding the bar, a

tapered shoulder on the collar for depressing the balls into the countersinks when shifted to proper position, means for shifting the collar, and means for engaging the sleeve and boring bar in slidable driving relation.

14. In a cylinder boring and grinding machine of the character described, a power driven sliding gear shaft lhaving slidingv gears for imparting motion to the bar driving mechanism, shifting members engaging grooves in the sliding gears and secured to shifting rods suitably supported and provided with interlock, a rack on said rods engaging pinions at one end of control shafts, the other end of the control shaft being suitably supported and provided with means for indexing and maintaining the sliding gears in proper relation with their mating gears.

15. In a cylinder boring and grinding niachine of the character described, a gear shifting control shaft having a pinion at one extremity for engaging a rack on the'shiftin'g member, at the other end bored to receive the round portion of a lever bracket carrying a pivoted lever, means for firmly fastening the bracket to the control shaft, a bearing bush- Jing interposed between the end of the shaft and a shoulder on the bracket, the bushing having a notched rim, the notches to engage the lever thereby holding the gears in proper position, a. spring and'l plunger for depressing the lever into the notches, a raised portion on lthe rim of the bushing to act as a sto for the lever, and means for supporting the bushing.

16. In a machine of t-he character described, a feed nutv supported'endwise and threaded upon a boring bar for the purpose of feeding said bar, a plurality of gears firmly secured to said nut, a gear mounted on a sleeverevolving in unison with the bar, a countershaft suitably .supported and carrying in fixed relation a pinion meshing with the gear on the sleeve, a plurality of gears rotatably mounted on the countershaft/an'd meshing with corresponding gears on the nut, a plunger operated by rack and pinion, slidably mounted in a. bore in the countershaft and havin a collar for engaging selectively balls retained in holes in the countershaft with countersinks in the bore of the rotatable gears on the countershaft, thereby engaging selectively the gears with the countershaft and providing a differential rotary movement between sleeve and nut, the plunger being formed toact as a ball retainer for the lidle gears.

17. A cylinder boring machine comprising a boring bar, an outboard support forV the boring bar comprising a bearing bushing provided with a pivoted ey for slidably engaging the boring bar, said bushinghaving a spherical outer surface, two adjustable retaining collars engaging said spherioalsurface, an annular member in which said co1- lars are mounted',lmeansffor adjusting said annular member radially, a housing inwhich said annular member is avdjustably mounted, provided with radial arms, brackets carried by said arms for attaching the housing to the cylinder to be bored, said annular member and housing having interengaging flat shoulders, said annular member having a tapered shoulder, and screws mounted in said arms for engaging said tapered shoulder for radially adjusting the annular member. v

18. A cylinder boring machine comprising a centralizing device includinga boring bar, a housing surrounding said bar, a plurality of arms projecting from said housing, a chuck scroll within the housing concentric with the bar, chuck-jaws engaging the scroll and slidably mounted in the projecting arms, said chuck jaws having retaining slots in their outer faces concentrically spaced with respect to the boring bar, slip jaws for gripping the bar of the cylinder mounted in said slots, plungers slidably mounted in said slip jaws for holding the slip jaws in the slots, the face of the sliding jaws being provided with grooves for receiving the ends of the plungers, and means for forcing the plungers into the grooves.

19. A cylinder boring machine comprising a transmission case, a power-driven worm shaft supported in said transmission case, thrust and radial bearing means for said worm shaft, a boring bar, a worm wheel concentric with the boring bar, a sleeve surrounding the boring bar, said worm wheel being freely rotatable on said sleeve, a, collar slidably mounted on the hub of the worm wheel, a plurality of balls seated in openings in the hub of the worm wheel, and retained therein by said collar, said sleeve being provided with countersinks in alinement with said balls, said collar being provided with a tapered shoulder for depressing the balls into the countersink when shifted to proper position, means for shifting the collar, and means for engaging the sleeve and boring bar in a slidable driving relation.

20. A cylinder boring and grindin machine of the character described, inclu ing a bar capable of rotary and longitudinal movement, a transmission case enclosin the `mech anismfor imparting motion to t e bar and earrymg a chuck jaws shdably retained within the arms, means for moving the chuck jaws outward or inward in a universal manner, an outboard bearing for the bar, and a tool-carrying head mounted on the bar. A 21. A cylinder boring machine comprising a boring bar mounted for longitudinal and rotary movement, transmission for said borin bar'mounted as a unit therewith," expansi le means engageable with the bore of the cylinder for centering the bar in the cylinder, and means outside of the cylinder for guiding the unit inits centering movement lurality of projecting arms,

and for securing it in centered position, said guiding means comprising guide members outside the cylinder and secured thereto and radially extending arms on said unit guided in said guide members.

22. A cylinder boring machine comprising a boring bar mounted for longitudinal and rotary movement, transmission for said boring bar mounted as a unit therewith, expansible means engageable with the bore of the cylinder for centering the bar in the cylinder, and means outside of the cylinder for guiding the unit in its centering movement and for securing it in centered position, said guiding and securing means comprising a guide member outside the cylinder and secured thereto, arms on said unit guided in said guides, and means for securing said arms against movement in said guide members.

23. A c linder `kioring machine comprising a boring ar mounted for longitudinal and rotary movement, transmission for said boring bar mounted as a unit therewith, expansible means engageable withthe bore o the cylinder for centering the bar in the cylinder, and means outside of the cylinder for guiding the unit in its centering movement and for securing it in centered position, said guiding and securing means comprising a guide member outside the cylinder and secured thereto, radially extending arms on said unit guided in said guides, and means for securing said arms against movement in said guide members.

24. A cylinder boring machine comprising a boring bar mounted for longitudinal and rotary movement, transmission for said boring bar mounted as a unit therewith, said transmission comprising variable speed means for effecting the ordinary axial movement of the bormg bar, rapid traverse means for effecting extraordinary axial movement of the boring bar, and means for preventing interference due to concurrent use of said variable speed means and rapid traverse means.

25,. A cylinder boring machine comprising a boring bar mounted for longitudinal and rotary movement, transmission for said boring bar' mounted as a. unit therewith, said transmission comprising two sets of variable 'speed transmissions, and means for preventing interference due to concurrent use of said two sets of variable speed transmissions.

26. A grinding head construction comprising a bar mounted for rotary and axial movement, a cutting head mounted on said bar, a power grinder mounted on said head, and a. fluid conduit leading through said shaft to said inder for supplying the power to the grin er as the head rotates.

In witness whereof, we have hereunto subscribed our names.

CHARLES B. COLE. OTTO LEROY LEW'IS.