US770156A - Boring-machine. - Google Patents

Description

'No. 770,156. PATENTED SEPT. 13, 1904. G. W. H. BLOOD.

BORING MACHINE.

APPLIOATION rum) OOT. 8.19%.

No MODEL- SBEEETS-SHEBT 1.

No. 770,156. PATENTED SEPT. 13, 1904.

0. W. H. BLOOD.

BORING MACHINE.

APPLICATION FILED OCT. 8, 1903. N0 MODEL. 3 sums-sum z.

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No. 770,156. PATENTBD SEPT. 13, 1904 0. w. H. BLOOD.

BORING MACHINE.

APPLICATION FILED 00w. 8, 190 s. N0 MODEL- ssnnn'rs-snnn'r a.-

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PATENT UEEICE.

CHARLES W. H. BLOOD, OF BOSTON, MASSACHUSETTS.

BORING'-IVI ACHINE..

SPECIFICATION forming part of Letters Patent No. 770,156, dated September 13, 1904. Application filed October 8,1903.; Serial No. 176,186.' (No model.)

or drilling wood, metal, or other material,

whereby the accuracy of the work is enhanced and practically absolute steadiness of the boring or drilling tool attained, so that straight true holes may be made, and by long bits, without danger of breaking or bending the same as it is fed into the Work, and at the same time the wear on the bit is reduced to a minimum.

I have also provided novel, simple, and efficient means for changing the position of the carriage on which the bit or other tool is rotatably mounted and for effecting a final and very accurate adjustment of the carriage.

These and various other novel features of my invention will be fully described in the subjoined specification and particularly pointed out in the following claims.

Figure 1 is a side elevation, partly broken out, of a machine of the classdescribed embodying one form of my invention. Fig. 1 is an enlarged detail, partly in section, of a suitable connection between the upper end of the bit-spindle and the means for feeding the same. Fig. 1 is a partly diagrammatic view of the manner of arranging the transmittingbelting between the main driving-shaft and a plurality of bit-spindles. Fig. 2 is anenlarged detail, partly in section and broken out between its ends, of the controller for changing and adjusting the position of the spindle-carrying carriage to be referred to. Fig. 3 is an enlarged detail, in rear elevation, of the coupling or connection between the controller and carriage, shown in Fig. 1 at the right of the standard. Fig. 1 is an enlarged front view of the combined bearing and clamp for the controller shown separated from the standard and to be described hereinafter. Fig. 1 is a rapidity.

' lateral support for the bit, and the means for effecting rotation of said support in unison with the spindle, the view being taken on the line 5 5, Fig. 1, and some portions thereof being broken out for the sake of clearness of illustration. Fig. 6 is a transverse sectional View of the lower portion of the bit-spindle and adjacent parts on the line 6 6, Fig. 5. Fig. 7 is an enlarged detail, on the irregular line 7 7, Fig. 8, of the bearing on the carriage for the bit-spindle and with the pulley-guard in section; and Fig. 8 is a top or plan view of the carriage and a portion of the standard as if taken on the line 8 8, Fig. 1, looking down.

1 have shown and described in detail more particularly a single-spindle boring-machine, as will appear clearly hereinafter, inasmuch as the novel features of my invention are applicable to a machine having one bit-spindle or a number, the number of spindles mounted on the carriage being immaterial.

To those familiar with boring and drilling machines the trouble experienced from the effect of lateral strains upon the bit or boringtool'is very well known, the vibration and tendency to bend (particularly when the bit is of small diameter and long) preventing the production of accurate work with desirable I have herein provided novel, simple, and efi'ective means for supporting the bit against lateral strain, the construction and arrangement being such that a running fit can be employed between the bit and supporting means, while all friction has been obviated save the very slight and unavoidable amount due to feed movement of the bit. These results are attained by causing the lateral bitsupport to rotate in unison with the bit-spindle, so that as bit and support rotate at the same speed no friction is generated, and the closeness of the fit between the bit and the lateral support is only governed by the ease of movement requisite for longitudinal feed of the bit.

riage.

Referring to Fig. 1, an upright standard A, usually a casting of suitable size and shape to sustain the operative parts'of the apparatus, has at its top two laterally-separated and parallel extensions A projecting beyond the front of the standard. As clearly shown in Fig. 1, the tops of said extensions very materially increase the effective length of the top of the standard from front to rear and provide a firm and strong support for the spindle-carriage, to be referred to, when moved to the front of the machine. The top of the standard and extensions is'planed flat and true to support the movable carriage, and guideways shown as bevel-sided bars A, are bolted onto the standard in parallelism, and their inner faces a overhang or are undercut to receive the correspondingly-shaped and flat base C of the carriage C, the outer faces 2 cooperating with the bases A of adjacent carriages if the machine is a multiple-carriage machine. The carriage is thus slidable on the top of the standard and its extensions A and between the guideways A the latter also preventing any tilting or tipping movement of the car- The carriage and its base are preferably made as an integral casting, the body portion of the carriage extending longitudinally of and being centrally located upon the base. Atransverse bridge A rigidly secured to or forming part of the standard near its front, spans thecarriage and has an attached guide-block A (see dotted lines, Figs. 7 and 8) to cooperate with the top of the body of the carriage and steady the same in its move ment back and forth on the standard.

A belt-pulley O is vertically journaled in offset bearings c 0 at the rear end of the carriage, and atthe front end of said carriage a vertical half-bearing or journal-box C is formed integral therewith, and, as shown in Figs. 1 and 5, it extends above and below the carriage-base (1*. The bearing is completed by a complemental member or cap C and directly above said half-bearing is a similar one, C completed by a complemental part C Figs. 1 and 7. The latter is held in place by suitable bolts 30, and the member C is secured by bolts 20 to the half-bearing C and herein I have'shown the two caps or complemental members as rigidly connected by a boxlike and substantially semicylindrical belt-' and-pulley guard G. When the parts are assembled, a strong rigid upright bearing is provided, separated between its upper and lower ends to admit therebetween the hub P of a pulley P, (see Fig. 5,) said pulley being semiinclosed by the guard. The ends of the bearing members cooperate with the upper and lower ends of the hub and position the pulley vertically, the center of rotation of said pulley being shown as midway between the extensions A and central with relation to the width of the carriage. I have herein shown the hub as having elongated upper and lower tubular extensions 10 p of reduced external diameter to enter and be rotatably supported in the separatedupper and lower bearings described, said extensions and main hub constituting what is hereinafter termed a carrier.

The lower end of the carrier is laterally enlarged to form an externally-threaded flange 10*, (see Fig. 5,) and a tubular extension P is secured to the carrier by a coupling-ring 19 of common construction, screwed onto the flange p and engaging an annular rib 5 on the extension. As shown in Fig. 5, the extension is of larger diameter than the carrier for a purpose to be described. The carrier is rigidly connected with the extension by the means shown (though any other suitable form of coupling may be employed) and rotate as one piece, said extension depending below the parts A of the standard, as clearly shown in Fig. 1. At its lower end the extension is provided with one or more longitudinal slits 6 and has a conical or tapered and externallythreaded foot 19 to receive a correspondinglyshaped clamp-nutp whereby the foot can be contracted or reduced in diameter.

A sleeve P is telescopically mounted within the extension P and of sufiicient length to permit a considerable longitudinal movement in or out of the extension, the lower end of the sleeve having secured to it in suitable manner a short thick tubular holder 79 This holder receives and sustains a lateral support for the boring tool or bit B, the support being shown as a deep ring or short tube P having an annular lip 12 on its lower end and of such internal diameter as will admit the easy longitudinal feed movement of' the bit through it, a set-screw 9 retaining the support P in its holder p Supports of different bores can thus be retained in the holder to cooperate with bits of different diameter. The support sustains the bit against lateral strainsthat is, such as are transverse to its length-and, as will appear, it steadies and and prevents chattering or vibration of the bit in the performance of its work. Thehead or haft b of the bit enters a socket 8X in the lower end of the bit-spindle S and is held in place by a set-screw s, as shown in Fig. 5, the extension P having openings 17 therein, through which access may be had to the said set-screw. One of said openings is near-the lower end of the extension, and the telescoping sleeve P is also provided near its lower end with an opening 18, so that if for any reason the bit must be removed when the spindle is near the end of its feed movement the operator can manipulate the set-screw 8 through the openings 17 and 18.

The bit-spindle S is considerably longer than the combined length of the carrier 19 9 and its extension P as clearly shown in Fig. 1, to provide for the requisite feed of the bit, and the diameter of the spindle is such that it will enter the carrier with an easy sliding fit, so that said carrier laterally supports it while permitting its longitudinal feed movement.

The carrier has two longitudinal keyways 22 therein, preferably diametrically opposite,

' in which are seated keys 23, having their ends upset at 24 to hold them in place, the keys entering key seats or grooves 8 extending from one to the other end of the bit-spindle. Consequently the spindle is rotated by or through the carrier in unison therewith, while longitudinal movement of thespindle to feed or withdraw the bit is freely permitted.

It will be remembered thatthe bit-supportp is connected to rotate with the carrier, so that the support and bit rotate in unison, thereby eliminating friction between them, while preserving all the valuable functions of the support, the only relative movement between support and bit being that 'due to feed of the latter.

So far as I am aware it is broadly new to provide a lateral support for and rotatable in unison with the bit, and 1 consider any means for effecting such operation as Within my invention. y

A bracket 0' is mounted on the carriage and has fulcrumed upon it at c an overhanging lever 0 0 the longer arm 0 being connected with the bit-spindle by suitable links 0, Fig. 1. The short arm 0 has attached to it one end of a strong spring S fixed at its other end to the carriage, the spring acting to retain the bit-spindle at the upper end of its feed-stroke. Any suitable connection may be used between the links and the spindle, and in Fig. 1 1 have herein shown the spindle annularly grooved at s to receive pins 50, extended thereinto from a recessed cap 0 which rotatably surrounds the upper end of the spindle, the links 0 being pivotally connected with the cap at o An operating rod or handle 0 depends from the free end of the lever-arm 0 at the front of the machine, whereby the operator can readily control the feed of the spindle.

The work W (shown in dotted lines, Fig. 1) can be supported in any desired manner heneath the bit-spindle, and the carriage is moved backward or forward to properly position the bit by means to be described.

It is desirable to adjust the position of the bit-support p relatively to the length of the spindle for different kinds of work, and such adjustment is made by loosening the clampnut 19 and sliding the sleeve P in or out of the extension P to bring the support to the desired position, whereupon the nut is set up and the sleeve securely clamped in adjusted position.

I have provided simple and effective means for moving the carriage back and forth uponthe standard and to accurately and finally position it whenso moved.

Referring to Fig. 1, a depending bracket 0 i is bolted to the under side of the carriage-base C near its rear end and passes down through an elongated opening (not showri) in the top of the standard A between the guideways A", the lower end of the bracket being turned rearward and passing through the openv back of the standard. Lateral ears 0 Fig. 3, are formed on the extremity of the bracket to sup.- port pivot-screws 0 on which is mounted the hub 0 of a coupling-nut 0 which is thus adapted to rock in a substantially horizontal plane. A controller having a bodily longitudinal movement and auxiliary rotative. and lateral movements is operatively connected at its rear end with the coupling-nut, and at its front end it is mounted in a combined bearing and clamp, as will now be described. Having reference more particularly to Fig. 2, the controller is shown as a rod f having one' end reduced in diameter to receive a threaded sleeve f, having an annular flange f at one end and considerably longer than the coupling-nut 0 as shown in Fig. 1. The sleeve is screwed into the nut, and then the re? duced end of the controller is passed through the sleeve, and a washer f is interposed between the end of the sleeve and a retainingnutf which is tightly screwed onto the reduced end of the controller, the latter be.- ing threaded for the purpose. The sleeve f is thus rigidly secured to the controller, so that rotation thereof will turn the sleeve in the coupling-nut and effect relative longitudinal movement of the sleeve and controller and coupling-nut at a very slow rate, and if the controller is held from longitudinal movement any ,rotative movement thereof will be transmitted through the coupling-nut and bracket 0 to the carriage C, moving the latter slightly back or forth on the standard A. At its front end acollarf, having an attached handle F, is secured to the controller, and a second collar f is made fast on the controller nearer its rear end (seeFig. '1) and a tube or sleeve f is loosely mounted on the controller between the collars. In Fig. 2 I have shown the opposed inner ends of the collars astapered to provide bearings for the ends of the sleeve f, and it will be obvious that while the latter is movable longitudinally or laterally with the controller f said controller can be rotated within the sleeve.

A combined bearing and clamp is shown in position on the front of the standard A in Fig. 1 and separately in front elevation. and enlarged in Figs. 4 and 4, it comprising a circular box-like casting ZLX, having in its circular top it a laterally-elongated opening 72/, through which the sleeve f is passed. As the controller is fulcrumed at its rear end on the pivotpins-0 a lateral swinging movement of the front end of said controller is permitted, and itsamplitude is governed by the difference between the diameter of the sleevef G and the length of the opening it. A clamp-block moves the controller to the right, viewing move the carriage backward or forward.

if, having a longitudinal slit 7L3, intersecting l a round hole It, is mounted to slide horizontally in the casting la the hole being large enough to normally permit the sleeve f to slide therethrrmgh. Short toggle members or knuckles it are mounted at their outer ends to rock in seats h in the wall of the casting (see dotted lines, Fig. 1, and full lines, Fig. 43,) while their inner ends rock in seats k in top and bottom of the clamp-block k The clamp-block is shown open in Fig. 4, the toggle members being swung to the right; but if it be moved to the left the toggle members will rock in the seats 7&6 to the position shown in Fig. 1, and they will then act to press the upper and lower parts of the block toward each other, this being permitted by the slit it and this sliding movement of the block is effected by moving the'controller to the left. When the clamp-block is thereby closed, it clamps the sleeve f and holds it firmly from longitudinal movement, though the controller f can be rotated within the sleeve.

Supposing that the operator desires to change the position of the carriage, he first Fig. L, and thereby slid es the clamp-block into open position, (shown in such figure,) and then he pushes in' or pulls out the controller to When by such movement the carriage is approximately in the desired position, the operator moves the controller to the left, moving the clamp-block into the position shown in Fig. 1, and thereby causing the clampblock to close on the sleeve f, as has been described, and thereby the controller is locked from longitudinal movement. By then rotating said controller in one or the other direction the coupling-nut 0 and connected carriage will be moved very slowly in or out, and the carriage is thereby adjusted with great accuracy and delicacy until the point of the bit is in the precise position required with relation to the work. This positioning and adjusting of the carriage by the manually-operated controller is easily and rapidly efifected from the front of the machine, and the carriage is maintained securely in adjusted position.

I have provided set-screws 70 and checknuts 71, Fig.- 1, to act upon the outer ends of the toggle members If and take up wear when necessary.

If a plurality of carriages are mounted on the standard, each will be provided with controlling means substantially as previously described.

A main driving-shaft M is mounted on the base ofthe standard, Fig. 1, and actuated from any suitable source of power, (not shown, said shaft having an attached belt-pulley F and power is transmitted therefrom to the spindle-driving pulley P by abelt M.. Shown in dotted lines, Fig. 1.)

1 wherein it is supposed that three carriages.

are employed, each with its bit-spindle, the several bit-spindles being indicated at S, S, and S with their connected driving-pulleys P P P the latter corresponding to pulley P. Figs.5 and 8. Pulleys G (3* C are mounted onthe rear ends of the several carriages and correspond to pulley C. (Indicated in Fig. 5 and shown in full lines, Fig. 1.) A guidepulley (1 is mounted on the standard, near the front thereof, Figs.- 1 and 8, but not shown in Fig. 1, as hidden by other parts of the apparatus. The belt M travels in the direction of the arrows, rising from the main driving-pulley M up to and over the guide and take-up pulley M and thence forward around the spindle-driving pulley P Fig. 1 and back around the pulley C on the carriage, upon which the spindle S is mounted. Thence the belt passes in turn around pulleys P and C, P and C and from. the latter pulley around the guide-pulley C mounted on the front of the standard. The belt then travels rearward over the guide-pulley M mounted on the standard at the back thereof, and down to the driving-pulley. Viewing Fig. 1 it will be manifest that any one of the several carriages may be moved in or out without altering the belt tension, because taking the center carriage, for instance, as the pulleyPis moved forward, taking up the belt, the latter will be given up by just as much as the pulley C moves forward in unison with it, and the same is true of any of the carriages, the object of the slack-take-up pulley M being merely to preserve the desired tension on the belt at all times. The operation will be precisely the same if only one carriage is used, for supposing that the two outside carriages are omitted in Fig. 1 the belt would pass directly from M to pulley P, around it, and backward to pulley C, and thence directly to and around the fixedlymounted guide-pulley C It will thus be manifest that my invention is not restricted to a boring-machine having merely one carriage and bit-spindle, but it is equally applicable to such an apparatus irrespective of the number of carriages. I have shown herein one practical embodiment of my invention without attempting to show the various changes or modifications which may be made therein by those skilled in the art without departing from the spirit and scope of my invention.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a boring-machine, a rotatable bit-spin dle, an annular support for and through which I the bit passes, and means to rotate said support in unison with the bit-spindle.

3. In a boring-machine, a rotatable bit-spindle, a device to support the side of the bit be yond its point of attachment to said spindle, and means to rotate the supporting device at the speed of and concentrically with the bitspindle.

4. In a boring-machine, a rotatable bit-spindle, a rotatable, lateral support for and concentric with the bit, and means to adjust said support longitudinally of the spindle.

5. In a boring-machine, a rotatable and longitudinally-movable bit-spindle, a lateral support for and concentric with the bit, means to retain it in fixed position relative to the length of the spindle and means to rotate said support and spindle in unison.

6. In aboring-machine, arotatable bit-spindle, means to move it longitudinally to feed the hit, an annular support for and through which the bit passes as it is fed, a carrier for said support, and a connection between said carrier and spindle whereby they rotate in unison while permitting longitudinal movement of the spindle.

7. In a boring-machine a rotatable bit-spindle, means to move it longitudinally to feed the bit, a support to contact with the side of and laterally sustain the bit, a tubular carrier for the support, concentric with the spindle, a bearing in which the carrier is rotatable but held from longitudinal movement, a connection between the carrier and spindle to effect their rotation in unison while permitting feed of the spindle, and means to rotate the carrier.

8. In a boring-machine, a rotatable bit-spindle, means to move it longitudinally to feed the bit, a lateral support for the bit, a tubular carrier concentric with said spindle, a telescopic connection between the carrier and said lateral support, to adjust the latter longitudinally of the bit, and means to rotate said bit-spindle and carrier in unison.

9. In a boring-machine, a rotatable bit-spindle, a ring-like lateral support for and through which the bit passes, a tubular carrieror quill connected to rotate with the spindle, a sleeve to which the lateral support is attached, telescopically mounted in the carrier, and means to clamp said sleeve from longitudinal movement in the carrier, to thereby maintain the lateral support in adjusted position.

10. In a boring-machine, a bearing, a tubular carrier rotatably mounted. therein and held from longitudinal movement, a bit-spindle rotatable in unison with, and longitudinally movable in said carrier, a ring-like lateral support for and to cooperate with the bit beyond its connection with the spindle, and means to connect the carrier and lateral support to rotate together while permitting adjustment of the support in the'direction of the length of the bit.

11. In a boring-machine, a rotatable carrier,

an adjustably-connected lateral support for the bit, a bit-spindle longitudinally slidable in the carrier and supported laterally thereby, means to effect their rotation in unison, and an end support for and also to effect feed of the spindle through the carrier, the lateral support for the bit rotating therewith and sustaining it against transverse strain as itis moved longitudinally by feed of the spindle.

12. In a boring-machine, a vertically-movable, rotatable bit-spindle, an overhead support and feed device for the spindle, a bitsupport beyond the lower end of and concentric with said spindle, and means to rotate said bit-support and spindle in unison.

13. In a boring-machine, an upright, rotatable tubular carrier, a bearing in which it is rotatable and held from longitudinal move ment, a bit-spindle longitudinally movable in and keyed to the carrier, means to effect longi tudinal movement of the spindle, a tubular extension secured to the carrier and having a contractible lower end, a sleeve telescoped therein, a clamping-nut to clamp sleeve and extension together, and an annular lateral support for the bit detachably connected with the sleeve, said support rotating in unison with the spindle. Y

14. In a boring-machine, a standard having laterally-separated, horizontal extensions at the front thereof, a carriage movable back and forth on the top of said standard and its extensions, a vertical bit-spindle rotatably. mounted on the carriage and depending between the extensions of the standard, and means to effect vertical feed of the spindle.

15. In a boring-machine, a standard having guideways on its top and extended beyond the front thereof, laterally-separated extensions forming a part of the standard, to sustain the projecting front ends of the guideways, a carriage slidable back and forth between the latter, an upright bearing on the front of the carriage, a tubular carrier rotatable in said bearing and depending between and below the extensions, a bit-spindle longitudinally movable in and rotatable with said carrier, a lateral support for the bit, sustained by said carrier, below the lower end of the spindle, and means mounted on the carriage to vertically support and effect feeding movement of the bit-spindle.

16. In apparatus of the class described, a standard, a carriage movable thereon, and means to vary the position of the carriage, said means including a controller longitudinally movable to approximately position the carriage, and having a rotative movement to effect final adjustment thereof.

17. In apparatus of the class described, a standard, a carriage movable thereon, means to change the position of the carriage, said means including a controller movable longitudinally to move the carriage from one to another position and having a lateral movement, and a device governed by such lateral movement to lock and unlock the controller from longitudinal movement.

18. In apparatus of the class described, a standard, a carriage movable back and forth thereon, and means to change the position of and lock the carriage in adjusted position, said means including a rotatable controller bodily movable longitudinally to approximately position the carriage, and a locking device rendered operative by lateral movement of said controller to hold the same from longitudinal movement, rotation of said controller when so held effecting final adjustment of the carriage.

19. In apparatus of the class described, a standard, a carriage movable back and forth thereon, a controlling member therefor having a longitudinal and a rotative movement and mounted on the standard, and an adjustable connection between said member and the carriage, longitudinal movement of said member moving the coupling and carriage therewith in unison, and rotative movement of the controlling member acting through said coupling to move the latter and the carriage relatively to said member, to accurately adjust the position of the carriage.

20. In apparatus of the class described, a standard, a carriage movable back and forth thereon, a coupling-nut movable with the carriage, a controlling member screwed into said nut and movable longitudinally to change the position of the carriage, and means to prevent such longitudinal movement while permitting rotation of the controlling member, to thereby effect through the nut a final and accurate adjustment of the carriage. I

21. In apparatus of the class described, a

' standard, a carriage movable back and forth thereon, a coupling-nut movable with the carriage, a controlling member screwed into said nut and movable longitudinally to change the position of the carriage, and means, including a clamp operated by lateral movement of the controlling member, to prevent longitudinal movement thereof and permit its rotation, to thereby act through the nut and effect a final accurate adjustment of the carriage.

22. In apparatus of the class described, a standard, a carriage movable back and forth thereon, a coupling-nut movable with the carriage, a controlling member screwed into said nut, an elongated sleeve loosely surrounding and longitudinally movablewith said member, a clamp mounted on the standard and through which the sleeve is extended, and operating means for the clamp governed by lateral movement of said controlling member, longitudinal movement of the latter and sleeve through the open clamp effecting a change in the position of the carriage, and rotative movementof said member when the clamp is closed upon the sleeve acting through the nut to efiect a final and accurate adjustment of the carriage.

23. In apparatus of the class described, a

standard, a carriage movable back and forth thereon, a manually-operated controller having a longitudinal movement to position, and an auxiliary independent rotative movement, to accurately adjust, the position of the carriage,a nut-and-screw connection between one end of said controller and the carriage, and a combined clamp and bearing for the other end of the said controller, mounted on the standard, said controller also having a limited lateral movement to open or close the clamp and thereby permit or prevent longitudinal movement of the controller.

2a. In apparatus of the class described, a standard, a carriage movable back and forth thereon, a coupling-nut pivotally connected with the carriage, a controller threaded at one endto cooperate with said rut, an elongated sleeve longitudinally movable with and rotatable on the controller, a split clamp through which the sleeve is slidable, and a clamp-support mounted on the standard and provided with closing-toggles for the clamp, the latter being movable longitudinally in the support, longitudinal movement of the controller moving the carriage in unison therewith to change its position, and lateral movement of said controller moving the clamp in its support to clamp the sleeve and thereby restrain the controller from longitudinal movement, rotation of the controller at such time acting through the nut to bring the carriage into accurate adjusted position.

25. In apparatus of the class described, a movable, bit spindle carrying carriage, and controlling means for said carriage, including a manually-operated member longitudinally movable to change the position of the carriage, said member being capable of rotative and lateral movement at any point of its bodily longitudinal movement, to accurately adjust the position of the carriage, and to hold said member from longitudinal movement and permit its rotative movement.

26. In a machine of the class described, a standard, a carriage movable back and forth thereon, a rotatable, upright bit spindle mounted on said carriage and depending be low it, means accessible at the front of the standard to effect feed of the bit-spindle, and separate means operative from the front of the standard to move the carriage, effect a fine adjustment thereof, and retain it in adjusted position.

27. In a machine of the class described, a vertical, longitudinally-movable bit-spindle,

means to secure a bit to one end thereof, a,

tubular support concentric With and through to this specification in the presence of two sub- Which the bit passes and located beyond such scribing Witnesses. end of the spindle, means to sustain said sup- 1 7 port in fixed position With relation to longi- CHAS BLOOD 5 tudinal movement of the spindle, and means Witnesses:

to rotate said spindle and support in unison. JOHN C. EDWARDS,

In testimony whereof I have signed my name EMILY C. HODGES.

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