US1962951A

US1962951A - Tool head

Info

Publication number: US1962951A
Application number: US581746A
Authority: US
Inventors: Myers C Conwell
Original assignee: LAURA E CONWELL
Current assignee: LAURA E CONWELL
Priority date: 1931-12-17
Filing date: 1931-12-17
Publication date: 1934-06-12
Anticipated expiration: 1951-06-12
Also published as: GB399050A; FR735250A; DE618134C; BE387995A

Description

TOOL HEAD Filed Dec. 17, 1951 3 Sheefcs-Sheet l Z'Smaentor WN A SN Kw \\n WW8 A, A; A) QM.

mw MT (Ittomeg June 12, 1934. Q CONWELL 1,962,951

TOOL HEAD Filed- Dec. 17, 1931 3 Sheets-Sheet 2 2 9 66' 2; .2 i [6 J6 J 1 A M J3 c9 16-3: A .24

F I /Q m? (6:

1y Z6 19 0 0 I 19 l l I 26 40 u W k attorney June 12, 1934. c CONWELL 1,962,951

TOOL HEAD Filed Dec. 1'7, 1931 3 Sheets-Sheet 3 I ZSnve'ntor Bu a.

(Itfqmeg Patented June 12, 1934 UNITED STA TES' TOOL HEAD Myers 0. Conwell, Milford, Com, minor to Laura E. Conwell, Milford, Conn.

Application December 17, 1931, Serial No. 581,746 r 31 Claims.

This invention is a tool head capable of use in boring, facing, counter-boring, recessing, turning,

spotting, undercutting, back-facing, and like operations in drill presses, milling machines, boring machines, lathes and other similar power operated machines.

One of the objects of the invention is to provide a tool head of the character mentioned which will be of compact, simple and'rugged construction, equipped with a tool-carrying cross-slide, and means by which radial adjustments of said slide may be under the control of the operator, at all times while the tool head and the machine spindle are rotating andt-he tool is operating. A further object is to provide simple means for imparting adjusting movements to the tool carrying slide. A further object is to provide means associated with said adjustment-imparting means by which finer micrometric gradations of adjustment may be obtained. A further object is to provide simple means for preventing accidental change or alteration of the slide adjustment during rotation of the-head. A further object is to provide means for locking the tool or carrier against reciprocable movement at any time and also for'releasing it at will during rotation of the tool head.

The invention will be hereinafter fully set forth and particularly pointed out in the claims.

In the accompanying drawings:-

Figure 1 is a vertical sectional view illustrating a tool head constructed in accordance with the invention. Figure 2 is a similar view at right angles to Figure 1. Figure 3 is a sectional view il lustrating a slight modification. Figure 4 is a diagrammatic view illustrating an arrangement for effecting an automatic feed of the tool. Figure 5 is a diagrammatic view of an arrangement for obtaining a continuous feed. Figure 6 is a tranverse sectional view on line 66, Figure 2, with parts removed. Figure '7 is a detail plan view illustrating the lock-actuating ring. Figure 8 is a detail view illustrating the resilient support for the lock-actuating ring. Figure 9 is a detail view illustrating a modification of the lock-actuating ring. Figure 10 is a detail sectional view illustrating another modification of said ring.

Referring to the drawings, 10 designates a tool body provided with a shank 11, and with an internal chamber 12 which communicates with a diametrically disposed guideway 13 at the lower end thereof. The lower portion of the guideway is closed by a cap 14 which is provided with a threaded flange l5, removably engaging a complemental threaded portion on the lower end of the body, said flange being cut away as indicated at 16 to provide clearance for the reciprocation oi the tool-carrying slide S. Obviously, in order that the cut-away portions 16 may coincide with the open ends of the guideway 13, as shown inFig. 1, the complemental threaded portions by which the cap is retained in place mustbe so coordinated that while the cap is completely tightened there will be no overlapping by the walls of the cutaway portions. Otherwise, free adjustment of the slide would be impeded.

Encircling the body 10 is a top plate 1'7, normally held in place by a locking nut 18, which in turn is prevented from rotating with respect to the shank 11 by means of a set screw 19. Said top plate is provided with a key way 1'7 which is engaged by a key 17 carried by body 10, so that the top plate will rotate with said body. An undercut portion 20 is formed in said top plate 17, and a similar portion 21 is formed in the lower portion of the body immediately above the guideway 13. Cooperating with the said undercut portion 21 is a complemental portion formed in the lower edge of a stop ring 22 which is normally held from rotation in suitable manner, as for instance, by a stop bar 23, such as is used in a tapping chuck. The undercut portions of the body and the stop ring cooperate in a well known manner to provide a ball race for an antifriction bearing.

Interposed between the stop ring 22 and the 1. top plate 17 is an adjusting ring 25, which is provided at its upper edge with an annular recess 26 formed with angularly disposed intersecting surfaces providing a shoulder, in which is loosely seated a complemental annular ball race member 2'7 cooperating with the undercut portion 20 of the top plate 17, to provide an antifriction bearing. Said member 2'7 is normally held against rotation with respect to the adjusting ring 25 by means of a pin 28, which is supported at its lower end in a portion or the stop ring 22.

Said pin also prevents creeping of the ring 2'7 with respect to the top plate 17. It will be noted that the adjusting ring is rotatively supported with respect to the stop ring and also with respect to the body 10.

The adjusting ring 25 is internally threaded and engages a correspondingly threaded actuator member 29 which slidably engages the pin 28, so that it is free for longitudinal reciprocation but is held against rotation with respect to the tool body and the adjusting ring. Slidably mounted upon the body 10 is a hub 30, which is provided with an internal rack bar 31. Said hub slidably engages the body 10, and is provided with a key way 30 engaging a key 30 carried by said .body so as to prevent rotation relative thereto. Said hub member is also operatively connected with the actuator member 29, so that adjustment of the adjusting ring 25 will impart rectilinear movement to the adjusting member, and its rack bar 31. The hub .30 and the adjusting member 25 may be operatively connected in any desired manner, but as shown the actuator member is provided with an internal flange 32, which cooperates with a fixed shoulder 33 on the hub 30 and an adjustable collar 34, engaging said hub, so as to provide ball races in which suitable antifriction members are mounted, as clearly shown in the drawings.

Rotation of the adjusting ring may be readily accomplished byhand, but it is preferred to construct the lower edge thereof with gear teeth 35, which mesh with complemental teeth of a pinion 36, rotatably supported by the stop ring 22. As shown, the pinion 36 is carried upon a shaft 37 mounted in a suitable bearing, and provided with a thumb knob 38 by means of which it may be rotated. If desired, the thumb knob may be dispensed with and a star wheel 39 substituted therefor (see Figure 4), and arranged to cooperate with a striker 40 mounted on the top plate, so that an automatic step-by-step cross feed may be obtained. Obviously the rate of feed may be varied by increasing or diminishing the number of teeth in the star wheel 39 or by varying the number of strikers. By means of this arrangement a valuable and inexpensive accessory for large size heads on heavy work is provided. The star wheel 39 is preferably mounted on the shaft 37 by any well known friction or other relief means, so as to prevent, jamming of the parts at the end of the tool travel, should the samabe overlooked.

If desired, a gear 41 may be substituted for the thumb knob (see Figure 5), and the same meshed with a normally fixedly positioned, vertically disposed rack 42. Said rack may be fastened to the work table or anchored to an upper part of the machine that does not move up or down, so that any vertical motion of the head will cause a continuous rotation of the gear and the pinion shaft on which it is mounted, thereby imparting rotation to the adjusting ring and gradually changing the setting of the tool as the whole head is raised or lowered in boring a hole.- As'shown, the rack is secured to the table, and is provided with a guide bar 43 for holding the gear in engagement -with the rack. By means of this arrangement it is possible to bore a taper hole, tapering in either direction according to which side of the gear the rack is meshed with. Obviously any sizedgear may be used, depending upon the degree of taper desired, and the rack may be put on either side of the gear to reverse the direction of feed, i. e. either tioned gear meshes with a rack- 55 formed in the top of the tool slide Said slideis provided with set screws 56,- by means of which the shank of a tool may be engaged and held in place. Suitable antifriction metal 57 may also be provided to reduce friction upon said slide.

In the form of the invention illustrated in Figure 3, a portion of the tool slide is provided with a tapered opening 58, and the set screws 56 are engaged with the shank 59 of an auxiliary tool block 60, which is arranged to carry the boring bar 61 in a horizontal position instead of vertically, so that large holes may be bored with a small tool head. A cap screw 62 engaging a suitable recess 63 in the auxiliary tool block also engages the threaded recess 58,

so as to aid the set screws 56 in retaining the auxiliary tool block in place.

said head. To accomplish this, the stop ring 22 is provided with an internal conical seat which is engaged by a pressure ring R having a taper side fitting said seat.

Said pressure ring is split as shown in Figure '7 and normally held against rotation with respect to the stop ring 22 by means of an adjusting screw R carried by the last mentioned ring and projecting between the split ends of the pressure ring. Suitable means, such as spring R Figure 8) may be employed to keep the ring R in a normal operative position. It is obvious that the screw R, being supported by the stop ring is adjustable while the tool head is rotating, because the stop ring is normally nonrotating. Any advance movement of the screw R forces the conical end thereof into the split portion of the pressure ring R, and causes said ring to expand, so that it will travel downwardly as viewed in Figures 1 and 2, on the taper seat of the stop ring. Said'movement applies pressure to clamping members R. slidably mounted in the tool body, and disposed diagonally so that their extremities will engage and exert a locking pressure upon the sides of the tool slide, thereby preventing sliding movement thereof. A slight reverse movement of the screw R will unlock the slide. I

In lieu of the split ring R and screw R the pressure ring R -may be formed. with a plurality of cam-like teeth or members T, which'are engaged by complemental teeth or members T' carried by the stop ring. See Figure 8.

If desired the pressurering may be provided with anti-friction bearings, as shown in Figure 9. Referring to said figure B designates a grooved ball race resting upon the ends of the clamping member R balls B being interposed between said race and the bottom of the pressure ring R.

In practice, assuming that the pressure ring R has been adjusted to permit free movement of slide S, all adjustments up to one-thousandths of an inch are made directly by manual manipulations of the large knurled adjusting ring 25, while for finer adjustments the milled thumb knob may be used and found more convenient. The micrometer slip collar 50 may be set to zero when starting to cut at any point, and by reason of the fact that it is equipped with a very fine scale, the most minute adjustments may be made with ease and certainty. If automatic adjustments are desired, either of the arrangements illustrated in Figures 4 and 5 may be employed, as the nature of the work to be performed may require.

In operation, the desired tool is placed in the tool slide S and locked by means of the set screws 56, after which the head 10 is rotated in a manner well known and understood in the art. By adjusting the ring 25, the actuator 29 is moved longitudinal-lycf the body, and imparts similar movements to the hub 30 and the rack member 31, and through the intervening gears 53 and 54, a sliding adjustment of corresponding ratio is imparted to the slide S. In many cases, such asboring a hole in a deep box jig, the stop bar 23 would be in the way. In such instances, the stop bar is removed and the entire tool head permitted to rotate. When an adjustment is required, the operator grasps the adjusting ring and stops it while the body of the head continues to rotate, thereby eilecting a desired adjustment. Or, the stop ring may be grasped and held stationary with one hand and the adjusting ring manipulated with the other hand to secure the desired adjus ment. This. however, is somewhat difiicult to do, and where this character of adjustment is desired, it is preferable to stop' or ho.d the stop ring and make the necessary adjustments through the thumb knob; after which the parts are released, and said parts will once more rotate in unison. After any adjustment of the ring 25, accidental disturbance of said adjustment is prevented by reason of the pitch of the screw threads connecting said adjusting ring 25 and the actuator member 29 and because said actuator member is normally held against rotation by the pin 28. If for any reason, it is desired that the,tool slide be held in fixed relation with respect to the tool head, said slide may be quickly locked by a slight adjustment of the screw R It will also be obvious that unlocking of the slide may be instantl effected.

The advantages of the invention will be readily understood by those skilled in the art to which it belongs. For instance, it will be noted that an exceedingly strong and rugged device is provided, which is capable of use in boring, facing, counterboring, recessing, turning, spotting, undercutting, back-facing and various other similar operations on drill presses, milling machines, boring mi'ls, lathes and the like. An important advantage is that the tool slide may be readily and easily adjusted during rotation of the tool head and while the tool is cutting, and that simple and efficient means are provided for preventing the rotating top plate from affecting or accidenta'ly altering these adjustments. A further advantage lies in the ease by which the adjusting ring may be manipulated either manually or automatically, and the fineness of the obtainable gradations of adjustment. Another and important advantage is obtained by the construction of the slideway for the tool slide, which is not limited in its use to a rotating tool head. A very important advantage of the invention is that by means of the locking mechanism disclosed, the tool slide may be positively locked against relative movement and quickly released from its locking mechanism, as occasion-may require. In this connection it will also be observed that the locking pressure produced by said locking means reacts to produce an additional friction between the stop ringand the adjusting ring, tending to prevent rotation of the adjusting ring while the locking mechanism is in operation.

. Having thus explained the nature of the invention and described an operative manner of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or all of the forms of its use, what is claimed is:-

1. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, a top plate connected with said head and rotatable therewith, an adjusting ring rotatably mounted between said top plate and said stop ring, means for counteracting the tendency of said body to impart rotations to said adjusting ring during rotation of the head, means for normally maintaining said adjusting ring in any of its adjusted positions and means operated by said adjusting ring for imparting movements to said cross-slide.

2. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable'stop ring, said bod-y being'rotatable with respect thereto, a top plate connected with said head and rotatable therewith, an adjusting ring rotatably mounted between said top pate and said stop ring, a bear-. ing member interposed between the top plate and said adjusting ring and loosely engaging said ring, means for preventing rotative movement of "said bearing member, means for normally maintaining said adjusting ring in any of its adjusted positions and means operated by said adjusting ring for imparting movements to said cross-slide.

3. A tool head of the character described comprising a body, a cross-slide rcciprocably mounted therein, a normally non-rotatable stop ring,

said body being rotatable with respect thereto,

cess in its upper edge, an annular bearing member loosely fitting said recess, means for preventing rotation of said bearing member, means for normally maintaining said adjusting ring in any of its adjusted positions and means operated by said adjusting ring for imparting movements to said cross-slide.

4. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring,

said body being rotatable with respect thereto,

a top plate connected to said head so as to retate therewith; an adjusting ring rotatablymounted between said top plate and said stop ring, said adjusting ring having an annular recess in its upper edge, a bearing member complemental to and loosely fitting said recess, means connected with the stop ring for preventing rotative movement of the bearing member, means for normally maintaining said adjusting ring in any of its adjusted positions and meansv operated by the adjusting ring for imparting movements to said cross-slide.

5. A tool head of the character described comprising a'body, a cross-slide 'reciprocably mount said body being rotatable with respect thereto, an adjusting ring rotatably mounted with respect to said stop ring, a hub slidably engaging said body, said hub and said body having complemental means for preventing relative rotation, so lv that the hub will rotate with said body, an actuator member operated by said ring and movable longitudinally of the'body, and having an operative connection therewith constructed and ed therein, a normally non-rotatable stop ring, 1146 arranged to impart movement to the hub, said 9 connecting means permitting rotation of the hub with respect to said actuator member, means for preventing rotation of said actuator member, means operatively connecting the actuator member and the adjusting ring, said means being constructed and arranged to prevent accidental movement of said adjusting ring, and means operated by said hub for imparting. movements to said cross-slide.

6. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, a top plate rotatable with said head, a rotatably mounted adjusting ring between said top plate and said stop ring, a bearing member loosely engaging the upper part of said adjusting ring and interposed between it and said top plate, an actuator member operated by said adjusting member, a pin anchored to said stop ring and engaging. said actuator member and said bearing parting movements to said cross-slide.

7. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, an adjusting ring rotatably mounted with respect to said stop ring, a hub slidably engaging said body, said hub and said body having com-' plemental means for preventing relative rotation, so that the hub will rotate with said body, a rack bar supported by said hub, an actuator member engaging said-adjusting ring and enclosing the hub, said actuator and said hub having complemental means connecting them, so that longitudinal movement of the actuator member imparts corresponding movement to the hub, said connecting means permitting rotation of the hub with respect to the actuator member, said connecting means being so constructed and arranged as to prevent accidental movement of said adjusting ring, means for preventing rotation of said actuator member, and means operated by said rack bar for imparting movements to said cross-slide.

8. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, a rotatably mounted adjusting ring movable with respect to said stop ring and also with respect to said body, means for counteracting the tendencyof the adjusting ring to rotate under influence of the rotation of said body, said body and said adjusting ring being movable relative to said means,

a hub slidably mounted on said body and connected to rotate therewith, means operated by said adjusting ring for imparting slidable movement to said hub, means for preventing accidental movement of said adjusting ring and means operated by movements of said hub for imparting movements to said cross-slide.

' 9. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said tion of said actuator member but permitting 1ongitudinal movement thereof, said last mentioned means being constructed and arranged to prevent accidental movement of said adjusting ring, a hub member enclosed Within said actuator member and provided with an annular shoulder and an adjustable collar, said actuator member having a flange projected between said shoulder and said collar, and means operated by said actuator member for imparting movements to said crossslide.

10. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, an adjusting ring rotatably mounted with respect to said stop ring and also with respect to said body,

\ said adjusting ring being internally threaded, a threaded actuator member engaging the threaded portion of said adjusting ring and having an internal annular rib, a hub enclosed within the actuator member and having means rotatively engaging said rib but including means cooperating with said rib for preventing relative longitudinal movement of the hub and'the actuator member, means preventing rotative movement of said actuator member but permitting longitudinal movement thereof, said last mentioned means being constructed and arranged to prevent accidental movement of said adjusting ring, a rack member carried by said hub, andmeans operated by said rack member for imparting movement to said.

cross-slide.

11. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, an adjusting ring rotatably mounted with respect to said stop ring and also with respect to said body, said adjusting ring being internally threaded, said adjusting ringbeing provided with gear teeth, a pinion engaging said teeth, said pinion being rotatably supported by said stop rin means for rotating said pinion so as to impart movement to the adjusting ring, means for normally preventing accidental movement of said adjusting ring and means operated by the adjusting ring for imparting movements to said cross-slide.

12. A tool head of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, an adjusting ring rotatably mounted with respect to said stop ring and also with respect to said body, said adjusting ring being internally threaded, a micrometer ring rotatably mounted upon said adjusting ring, means for normally preventing relative' rotations of the micrometer ring and said adjusting ring, means for imparting movement to said adjusting ring, means for normally preventing accidental movement of said adjusting ring and means operated by said adjusting ring for imparting movement to said cross-slide.

13. A tool of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop ring, said body being rotatable with respect thereto, an adjusting ring rotatably mounted with respect to said stop ring and also with respect to said body, means operated by said adjusting ring for imparting movements to said cross-slide, means for normally preventing accidental movement of said adjusting ring and means for imparting rotative adjustments to said adjusting ring.

14. A tool of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally nonrotatable stop ring, said body being rotatable with respect thereto, an

adjusting ring rotatably mounted with respect to said stop ring and also with respect to said body, means operated by said adjusting ring for imparting movements to said cross-slide, means for normally preventing accidental movement of said adjusting ring and means for imparting step-bystep rotative movements to said adjusting ring.

15. A tool of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop-ring, said justing ring rotatably mounted with respect to said stop ring and also with respect to said body, means operated by said adjusting ring for imparting movements to said cross-slide, a shaft for actuating said adjusting ring, an actuator member connected with said shaft, means for imparting step-by-step movements to said shaft, and means for normally preventing accidental movement of said adjusting ring, 16. A tool of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop-ring, said body being rotatable with respect thereto, an

adjusting ring rotatably mounted with respect to said ring and also with respect to said body, means operated by said adjusting ring for imparting movements to said cross-slide, means for imparting a continuously progressive rotative movement to said adjusting ring, and means for normally preventing accidental movement of said adjusting ring.

17. A tool of the character described comprising a body, a cross-slide reciprocably mounted therein, a normally non-rotatable stop-ring, said body being rotatable with respect thereto, an adjusting ring rotatable with respect to said stopring and also with respect to said body, means operated by said adjusting ring for imparting movements to said cross-slide, a shaft for actuating said adjusting ring, an actuator member connected with said shaft, means for imparting a continuous rotation to said shaft in a predetermined direction, and means for normally preventing accidental movement of said adjusting ring.

18. In a tool of the character described, a body, a cross-slide reciprocably mounted therein, means for imparting slidable adjustments to said slide during rotations of said body, a pressure ring normally occupying a fixed position, means for adjusting said ring, and slide'engaging members operatively associated with said pressure ring.

19. In a tool of the character described, a body, a cross-slide reciprocably mounted therein, means for imparting slidable adjustments to said slide during rotations of said body, a stop ring, a split pressure ring adjustably engaging said stop ring, slide-engaging members operatively associated with said ring, and means for expanding said split pressure ring so as to apply pressure upon said slide-engaging members.

20. In a tool of the character described, a body, a cross-slide reciprocably mounted therein, means for imparting slidable adjustments to said slide during rotations of said body, a stop ring having an inclined surface portion, a split pressure ring having an inclined face bearing upon.

said inclined surface, an adjusting screw mounted body being rotatable with respect thereto, an adin said step ring and engaging said pressure ring,-

and slide-engaging members associated with said pressure ring.

21. In a tool of the character described, a body, a cross-slide reciprocablymounted therein, means for imparting slidable adjustments to said slide during rotations of said body, a stop ring having an inclined surface portion, a split pressure ring having an inclined face bearing upon said inclined surface, an adjusting screw mounted in said stop ring and having one end engaging the split portion of said pressure ring, and slideengaging members operated by said pressure ring.

22. A tool head of the character described comprising a body, a normally non-rotatable stop ring, said body being rotatable with respect thereto, a cross slide reciprocably supported by said body and mounted to conform to rotative movements thereof, a rotatable adjusting ring freely movable with respect to said stop ring and said body, means connected with said stop ring for counteracting the tendency of. said adjusting ring to rotate with said body, means car- 'ried by said body for reciprocatively adjusting said cross slide, and means interposed between said adjusting ring and said cross slide adjusting means for maintaining an operative connection between them at all times.

23. In a tool of the character described, a body, a cross slide reciprocably mounted in said body, means for imparting rectilinear adjustments to said slide during rotation of said body, a non-rotatable stop ring, and means cooperating with said stop ring for normally locking said slide against movement.

24. In a tool of the character described, a body, a cross slide reciprocably mounted in said body, means for imparting rectilinear adjustments to said slide, locking means for normally holding said slide against movement, a friction member cooperating with said ring and controlling said locking means, and means .carried by said stop ring for adjusting said friction member.

25. In a tool of the character described, a tool body, a cross slide reciprocably mounted in said body, means for imparting rectilinear adjustments to said slide, a stop ring, a friction ring, said. rings having complemental reacting surfaces, means for adjusting said friction ring so as to cause said reacting surfaces to impart movement to the friction ring, and means controlled by the friction ring for locking said slide.

26. In a tool of the character described, a tool body, a cross slide reciprocably mounted in said body, means for imparting rectilinear adjustments to said slide, an expansible friction ring of resilient material, means for expanding said ring, locking members mounted in the body and positioned to engage said slide, and means for causing said ring to apply pressure upon said looking members as it is expanded.

27. In a tool of the character described, a tool body, a cross slide reciprocably mounted therein, means for imparting rectilinear adjustments to said slide, means for locking said slide against movement, a friction ring, and means operable during rotation of said body for adjusting said friction ring toward and from said locking means, so as to apply or remove pressure from said locking means.

28. In a tool of the character described, a tool body having an internal open ended transversely disposed guideway, said body having external screw threads, a cap having a flange provided with an internal screw thread complemental to 15o lower portion having an external screw thread, a cap having an internally threaded annular flange for engaging the threaded portion of said body, said flange having opposite openings therein registering with the ends of said guideway, said threads being so coordinated that while the cap is completely tightened the openings in said flange will register with the ends of the guideway, a cross slide movably mounted in said guideway and the openings in said flange, and means for adjusting said slide.

30. The combination with a tool body having a cross slide reciprocably mounted therein, said slide having a vertically disposed recess therein, a supplemental auxiliary tool block having a shank constructed to fit within .said recess,

means for clamping said shank within said recess, and means in addition to said clamping means for securing said auxiliary block to said slide, said auxiliary block having a tool-receiving chamber parallel with said slide.

31. The combination with a tool body and a cross slide reciprocably mounted therein, said slide having a vertically disposed recess therein, of a complemental auxiliary tool block having a-shank constructed to fit into said recess, means for clamping said shank within said recess, said auxiliary tool block having a tool-receiving chamber parallel with said slide and a recess in said last mentioned tool-receiving chamber, andmeans in the last mentioned recess for additionally securing said auxiliary tool block to said guide.

MYERS C. CONWELL.