US3628400A

US3628400A - Indexing turret

Info

Publication number: US3628400A
Application number: US27945A
Authority: US
Inventors: Ronald D Chope; Frank A Hevonkoski
Original assignee: Snyder Corp
Current assignee: SNYDER ACQUISITION Corp 3400 EAST LAFAYETTE DRIVE DETROIT MICHIGAN A CORP OF MICHIGAN; Snyder Corp
Priority date: 1970-04-13
Filing date: 1970-04-13
Publication date: 1971-12-21
Anticipated expiration: 1988-12-21
Also published as: GB1347696A; CA929733A

Abstract

A tool turret mounted for rotation about and axial movement with a threaded sleeve carried by a base. The freely rotatable turret is selectively locked to the base by a locknut carried by the base and threadingly engaging the sleeve which axially displaces the tool turret to urge curvic couplings fixed to the turret and the base into locking engagement. The turret is rotated or indexed by a rack and a gear fixed to the turret for axial and rotary movement therewith. The gear and rack both have segmented teeth with the segments axially spaced so they disengage when the turret is locked and become engaged to index the turret only when it is axially displaced to unlock the curvic couplings.

Description

Unite States Patent Primary Examiner-William F. O'Dea Assistant Examiner-F. D. Shoemaker A ttomey-Barnes, Kisselle, Raisch & Choate ABSTRACT: A tool turret mounted for rotation about and axial movement with a threaded sleeve carried by a base. The freely rotatable turret is selectively locked to the base by a locknut carried by the base and threadingly engaging the sleeve which axially displaces the tool turret to urge curvic couplings fixed to the turret and the base into locking engagement. The turret is rotated or indexed by a rack and a gear fixed to the turret for axial and rotary movement therewith. The gear and rack both have segmented teeth with the segments axially spaced so they disengage when the turret is locked and become engaged to index the turret only when it is PATENTEDUEB21 m?! SHEET 1 OF 6 INVENTORS QQNALD D. CHDPE FRANK A.HEVONKQSKI ATTORNEYS slezadoo PATENTED D5621 I97! SHEET 2 OF 6 INVENTORS RONALD D. CHOPE FRANK A. HEVONKO'SKQ Fan-Z ATTORNEYS PATENIED [115221 I97] SHEET 3 [1F 6 IN VENTORS RONALD D. CHOPE FRANK A0 HEVONKOSKI ATTORNEYS PATENTEU [JEBZ] {9H SHEET [1F 6 RONALD D. HOPE FRANK Ac HEVOMKOSM ATTORNEYS PATENIEB BEBE] I97! SHEET 5 UF 6 INVENTORS gem-v.0 D. CHOPE BXBANK A. HEVIONKOSK! ATTORNEYS PATENTEU M1321 [971 3523400 SHEET 5 [IF 6 INVENTORS RONALD D. CHOPE FRANK A. HEVON K08 Kl ATTORNEYS INDEXING "runner This invention relates to indexing turrets and more particularly to an automatic turret for machine tools such as vertical lathes and the like.

In this invention a curvic coupling is attached to a tool turret connected to a threaded sleeve for free rotation about the axis of the sleeve. A second curvic coupling is fixed to a base and positioned to underlie the first coupling and a nut engages the sleeve and bears on the base. Rotation of the nut in one direction urges the curvic couplings into locking engagement and rotation in the other direction disengages the curvic couplings so that the tool turret can be rotated with respect to the base. A shaft is fixed at one end to the tool turret and extends axially through the sleeve with a fluted gear fixed to the other end. A fluted rack cooperates with the gear so that the tool turret can be rotated in either direction by movement of the rack only when the curvic couplings are unlocked or disengaged.

Drawings illustrating an embodiment and the features of this invention accompany this disclosure and are briefly described as:

FIG. I, an end view of an indexing turret constructed in accordance with this invention mounted on the ways of a vertical turret lathe.

FIG. 2, a fragmentary end view partially in section of the indexing turret of FIG. 1.

FIG. 3, a sectional view on line 3-3 of FIG. 2 illustrating the relationship of some of the component parts with the tool turret in the locked position.

FIG. 4, a fragmentary view partially in section similar to FIG. 3 illustrating the tool turret in the unlocked position.

FIGS. 5 and 6, plan views of the tool turret and base curvic couplings respectively.

FIG. 7, a fragmentary view partially in section on line 7-7 of FIG. 2 illustrating in solid and phantom lines the positions of the actuating bar when the tool turret is locked and unlocked respectively.

FIG. 8, a fragmentary sectional view on line 6-6 of FIG. 2 illustrating the disengagement of the tooth segments of the gear and rack when the tool turret is in the locked position.

FIG. 9, a fragmentary sectional view similar to FIG. 8 illustrating the engagement of the tooth segments of the gear and rack when the tool turret is in the unlocked position.

FIG. 10, a fragmentary view of the teeth of the curvic couplings illustrated in solid and phantom lines the locked and unlocked positions respectively of the curvic couplings.

Referring to the drawings:

FIGS. I and 2 illustrate an indexing turret 10 on a vertical turret lathef'lhe lathe has a carriage l2 movably mounted on ways 14 with a cross slide 16. Cross slide 16 carries and provides a base for indexing turret 10.

As shown in FIGS. 3 and 4, indexing turret 10 has a tool turret 18 with recesses 20 and holders 22 adapted to receive and secure tools 24 to the turret. A curvic coupling 26 is secured by keys 26 and capscrews 30 to the inner face of tool turret 16 and is engageable with a mating curvic coupling 32 secured in a circular recess 34 in the outer surface of base slide 116 by keys 36 and capscrews 38. A threaded bolt member or sleeve 40 with a ring 42 on one end is connected to tool turret 18 by entrapping ring 42 within a reentrant circular groove formed by the cooperation of curvic coupling 26 with a circular recess 43 in the inner face of tool turret 18. There is a slight clearance between ring 42 and the reentrant groove so tool turret 18 can rotate freely about sleeve 40. A threaded locking member or nut 44 with a flange 45 bearing on a shoulder 46 of base slide 16 engages threaded sleeve 40 to urge

curvic couplings

26 and 32 into locking engagement. A plug body 48 attached to and engaging in a recess 49 in the inner face of base slide 116 provides a surface for nut 44 to bear on so that it can axially displace sleeve 40 to unlock

curvic couplings

26, 32. Preferably, the threads of sleeve 40 have a double lead to increase the displacement of the sleeve per revolution of nut 44.

A central shaft 50 extends axially through sleeve 40 and is journaled for free rotation therein by bronze bushings 52. Shaft 50 has an end plate 54 with two keyways 56 at right angles to each other and is fixed to tool turret 18 by capscrews 56 and four keys 60 engaging in corresponding keyways 62 in turret 16. The other end of shaft 50 is journaled in a bronze bushing 64 carried by plug 46 and has a gear 66 splined thereto and axially fixed thereon by entrapment between a bushing 65 bearing on a shoulder 67 and a nut 68 keyed against rotation by a pin 70. To prevent the sleeve 40 from rotating with locknut 44, a guide pin '72 is held in plug 48 by a setscrew 74 and slidably engages in a blind hole 76 in the sleeve. Preferably hole 76 is put in sleeve 40 when turret 10 is assembled to simplify locating the hole and avoid alignment problems. A dust seal to protect the curvic couplings from contamination is provided by a ring 75 fastened to base slide 16 and having a circular ridge 77 extending into a circular groove 79 in the inner face of tool turret 18. As shown in FIG. 4, the height of ridge 77 and depth of groove 79 are such that they remain engaged when tool turret 18 is unlocked.

As shown in FIGS. 5. 6 and 10,

curvic couplings

26 and 32 are annular rings or racks with radially extending and circumferentially spaced complementary or

mating teeth

78 and 80. The spaced teeth of

curvic couplings

26 and 32 provide a plurality of detents and cooperating sockets so that when the couplings are urged together so the teeth mesh they interleave in locking engagement so the couplings cannot be rotated with respect to each other. Preferably each curvic coupling has an equal number of teeth and the number of teeth in each coupling is selected so that they are properly aligned for locking engagement at each station or index of tool turret 18. If the number of teeth in each coupling can be divided without a remainder by the number of stations of tool turret 18 the teeth of

couplings

78, 80 can be urged into interleaved locking engagement at each station of tool turret 18. Keyways 81 in coupling 26 receive keys 28 to secure coupling 26 to tool turret 18. A pin 82 is retained in a blind hole in curvic coupling 26 by a setscrew 84. Pin 82 can extend into any one of four locating holes 86 equally spaced at intervals in coupling 32 to provide four positions or stations for tool turret l8. Curvic coupling 32 has a plurality of circumferentially spaced coun terbores 88 and keyways 89 to receive capscrews 38 and keys 36 (FIG. 2) to secure the coupling to base slide 16. The use of curvic couplings to lock the tool turret to the base provides an extremely rigid indexing turret structure which reduces tool chatter and vibration on heavy machining operations.

As shown in FIGS. 2 and 7, locknut 44 is rotated by an actuator bar 90 retained for sliding movement by a slot 92 in plug 48 and reciprocated by a ram of a hydraulic cylinder 94. Cylinder 94 is mounted on base 16 and its ram is connected to actuator bar 90 through piston rod 96 and a lost-motion connector 98. Actuator bar 90 has a cross slot 100 which retains for transverse sliding motion a block 102. A pin 104 with a flange on one end is retained in block 102 and is secured to nut 44. Pin I64 is free to rotate within block 102 and when actuator bar 90 moves from the solid to the phantom line position shown in FIG. 7, block 1102 slides transversely to the motion of bar 96 (as shown in FIG. 2) and rotates nut 44 to unlock the tool turret. Preferably, the pitch and lead of the threads of sleeve 40 and the depth of the teeth of

curvic couplings

26, 32 are selected so that the rotation of nut 44 through an arc of 70 will move tool turret 18 from the locked to the unlocked position.

When unlocked, tool turret I8 is rotated by gear 66 and a rack I66 shown in FIGS. 3 and 4 retained by a slot 108 in plug 46 to engage gear 66. As shown in FIGS. 8 and 9, each tooth N6 of rack 1106 is divided into a plurality of segments by longitudinally extending flutes or grooves 118 and each tooth 120 of gear 66 is segmented by circumferential flutes or grooves I222. The segments of teeth I16 and 120 are axially spaced such that as shown in FIG. 8 rack 106 can be reciprocated without its teeth engaging the teeth of gear 66 when tool turret I6 is locked and as shown in FIG. 9 will engage with the teeth of gear 66 only when the tool turret is axially displaced to the unlocked position. As shown in FIG. 2, rack R06 is reciprocated by a ram of a cylinder 1 10 mounted on base slide 16. The ram of cylinder 110 is connected by rod H2 and lostmotion coupling 114 to rack 106.

In operating indexing turret l hydraulic cylinder 94 is energized to move actuating bar 90 downward as viewed in FIG. 2 or from the solid line to phantom position shown in FIG. 7 thereby rotating locking nut 44 clockwise (as viewed in FIG. 2). Clockwise rotation of nut 44 axially advances sleeve 40 and tool turret 18 thereby disengaging

curvic couplings

26 and 32 as shown in FIGS. 4 and 10 and engaging rack 106 and gear 66 as shown in FIG. 9. Since the teeth of rack 106 and gear 66 are engaged when tool turret 18 is unlocked, energizing cylinder 110 to move rack 106 downward (as viewed in FIG. 2) rotates gear 66 and shaft 50 counterclockwise. Rotation of shaft 50 advances or indexes tool turret 18 so that a tool 24 is properly positioned with respect to a workpiece. After tool turret 18 has been advanced, cylinder 94 is energized in the opposite direction to move actuating bar 90 upward (as shown in FIG. 2) thereby rotating locknut 44 counterclockwise (as shown in FIG. 2). counterclockwise rotation of locknut 44 axially retracts tool turret l8 and urges

curvic couplings

26 and 32 into firm locking engagement as shown in FIGS. 3 and 10. Guide pin 82 assures that the curvic couplings are properly aligned before disengagement of gear 66 and rack 106 and also that tool turret 18 has been indexed or advanced a whole rather than a fraction of a station. Guide pin 82 also prevents scuffing of the teeth of gear 66 and the curvic couplings as they disengage and engage. Locking tool turret E8 in position disengages the teeth of rack 106 and gear 66 (as shown in FIG. 8) so that cylinder 110 can be energized to move rack 106 either upward or downward (as viewed in FIG. 2) to position rack 106 to turn tool turret 18 in the proper direction to select the next station. Preferably, rack 106 is long enough to rotate or index tool turret 18 through all of its stations in a single unidirectional stroke. With this arrangement tool turret 18 can be advanced more than one station without momentarily stopping and locking the turret at each intermediate station. Also rack 106 can turn tool turret 18 in either direction of rotation to reach the desired station. Thus, the indexing cycle time can be reduced because the path of rotation containing the least number of intermediate stations can be used and the turret is not momentarily stopped at intermediate stations when indexing the tool turret to the desired station. Also, if desired, the tool turret can be unidirectionally indexed.

What is claimed as new is as follows:

1. An indexing turret for a machine tool comprising a base, a tool turret mounted for rotation about and movement along an axis with respect to said base, detent means and socket means connected to said base and said tool turret to lock said base and said tool turret against rotation with respect to each other when said tool turret is axially displaced along said axis such that said detent means and said socket means are engaged; displacement means carried by said base and operably connected to said tool turret to axially move said tool turret to a first position wherein said socket means and detent means are disengaged so that said tool turret is free to rotate and to a second axially displaced position wherein said socket means and said detent means are firmly engaged so said tool turret is locked against rotation with respect to said base, and a gear operably connected to said tool turret and axially movable therewith, said gear having a plurality of teeth and at least one circumferential groove through said teeth dividing each tooth into at least two segments, aNd a rack carried by said base for longitudinal sliding movement, said rack having a plurality of teeth and at least one longitudinal groove through said teeth dividing each tooth into at least two segments, said gear and said rack being positioned with respect to each other other such-that said tooth segments are disengaged when said detent means and socket means are locked in engagement and become. engaged when said tool turret is axially moved so that said detent means and socket means are disengaged.

2. The indexing turret of claim 1 in which said displacement means comprises a nut member and a bolt member each having mating threads thereon, one of said members connected to said tool turret and the other of said members carried by said base, and means operably connected to one of said members for rotating it with respect to the other member such that rotation of one member with respect to the other in one direction moves said tool turret axially and urges said detent means and socket means into locking engagement and rotation in a direction opposite to said one direction moves said tool turret axially and disengages said detent means and said socket means.

3. The indexing turret of claim 2 in which said last-mentioned means for rotating said members with respect to each other comprises an actuator bar carried by said base for longitudinal sliding motion therein, said actuator bar having a generally transverse cross-slide, and a follower block carried by said cross-slide and operably connected to said one member such that said one member is rotated by longitudinal movement of said actuator bar.

4. The indexing turret of claim 1 in which said detent means comprises a first rack having a plurality of teeth thereon and said socket means comprises a second rack having a plurality of teeth thereon, said teeth of said racks being adapted to mesh with each other when urged into firm engagement to lock said tool turret and said base against rotation with respect to each other.

5. The indexing turret of claim 4 in which each of said racks comprises a ring each having a plurality of integral generally axially extending and circumferentially spaced teeth on one face thereof.

6. The indexing turret of claim 2 in which said detent means comprises a first rack having a plurality of teeth thereon and said socket means comprises a second rack having a plurality of teeth thereon, said teeth of said racks being adapted to mesh with each other when urged into firm engagement to lock said tool turret and said base against rotation with respect to each other.

7. The indexing turret of claim 1 in which said detent means comprises a first ring having a plurality of generally radially extending and circumferentially spaced teeth on one face thereof and said socket means comprises a second ring having a plurality of radially extending and circumferentially spaced teeth on one face thereof, said teeth of said rings being adapted for being urged into meshing engagement to prevent rotation of one of said rings with respect to the other of said rings, said displacement means comprises a sleeve coaxial with said tool turret and connected thereto for axial movement therewith and rotation thereto, said sleeve having double lead threads thereon, a locknut carried by said base, said locknut having mating threads and threadingly engaging said sleeve, and an actuator bar carried by said base for sliding longitudinal movement generally transverse to the axis of rotation of said tool turret and operably connected with said nut to rotate said nut with respect to said sleeve, and a shaft extending through and journaled for free rotation within said sleeve and connected to said tool turret and said gear.

8. An indexing turret for a machine tool comprising a base, a threaded nut member carried by said base, a sleeve member carried by said base and having threads mating with said threads of said nut member, one of said members being adapted for rotary movement with respect to the other of said members and said sleeve member being adapted for axial movement with respect to said base in response to rotary movement of said one member, a tool turret connected to said sleeve member for axial movement therewith and rotation in relation thereto, detent means and socket means connected to said base and said tool turret to lock said base and said tool turret against rotation with respect to each other when said tool turret is axially displaced by said nut and sleeve members on said axis such that said detent means and said socket means are engaged and to release said base and said tool turret to be is axially displaced on said axis by said nut member and said sleeve member such that said detent means and said socket means are disengaged, and a drive shaft coaxially extending through said sleeve, connected to tool turret, and adapted for rotating said tool turret when said socket means and said detent means are disengaged.

9. The indexing turret of claim 8 which also comprises an actuator bar carried by said base for longitudinal sliding motion therein generally transverse to said axis, a generally transverse cross-slide on said actuator ban-and a follower block carried by said cross-slide and operably connected to said one member such that said one member is rotated by longitudinal movement of said actuator bar.

10. The indexing turret of claim 8 which also comprises a gear operably connected to said drive shaft and axially movable therewith, said gear having a plurality of teeth and at least one circumferential groove through said teeth dividing each tooth into at least two segments, and a rack carried by said base for longitudinal sliding movement, generally transverse to said axis, said rack having a plurality of teeth and at least one longitudinal groove through said teeth dividing each tooth into at least two segments, said gear and said rack being positioned with respect to each other such that said tooth segments are disengaged when said detent means and socket means are locked in engagement and become engaged when said tool turret is axially moved so that said detent means and socket means are disengaged.

Ill. The indexing turret of claim 8 in which said detent means and said socket means comprises first and second racks in the form of a ring each having a plurality of integral, generally radially and axially extending and circumferentially spaced teeth in one face thereof with the teeth of said racks being adapted to mesh with each other when urged into firm engagement to lock said tool turret and said base against rotation with respect to each other.

12. The indexing turret of claim 14 in which said detent means and said socket means comprises second and third racks in the form of a ring each having a plurality of integral, generally radially and axially extending and circumferentially spaced teeth in one face thereof with the teeth of said second and third racks being adapted to mesh with each other when urged into firm engagement to lock said tool turret and said base against rotation with respect to each other.

3 3 I UNHED STATES PATENT OFFICE QERTIFKCATE OF CQRREC'EION Patent No, 3 628, 400 Dated December 21, 197].

Inventor(s) Ronald D. Chope and Frank A. gevonkoski It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 71., cancel ."other" (second occurrence) Column 4, line 29, after "generally" insert radially and Column 6, line 13, change "14" to l0 3ig ned and sealed this 2nd day of. May 1972.

Attest:

EDNARDjfiLFLETCHER, JR. ROBERT GOT'I'SGHALK Atc estlng Officer Commissioner of. Patents

Claims

1. An indexing turret for a machine tool comprising a base, a tool turret mounted for rotation about and movement along an axis with respect to said base, detent means and socket means connected to said base and said tool turret to lock said base and said tool turret against rotation with respect to each other when said tool turret is axially displaced along said axis such that said detent means and said socket means are engaged; displacement means carried by said base and operably connected to said tool turret to axially move said tool turret to a first position wherein said socket means and detent means are disengaged so that said tool turret is free to rotate and to a second axially displaced position wherein said socket means and said detent means are firmly engaged so said tool turret is locked against rotation with respect to said base, and a gear operably connected to said tool turret and axially movable therewith, said gear having a plurality of teeth and at least one circumferential groove through said teeth dividing each tooth into at least two segments, aNd a rack carried by said base for longitudinal sliding movement, said rack having a plurality of teeth and at least one longitudinal groove through said teeth dividing each tooth into at least two segments, said gear and said rack being positioned with respect to each other other such that said tooth segments are disengaged when said detent means and socket means are locked in engagement and become engaged when said tool turret is axially moved so that said detent means and socket means are disengaged.

8. An indexing turret for a machine tool comprising a base, a threaded nut member carried by said base, a sleeve member carried by said base and having threads mating with said threads of said nut member, one of said members being adapted for rotary movement with respect to the other of said members and said sleeve member being adapted for axial movement with respect to said base in response to rotary movement of said one member, a tool turret connected to said sleeve member for axial movement therewith and rotation in relation thereto, detent means and socket means connected to said base and said tool turret to lock said base and said tool turret against rotation with respect to each other when said tool turret is axially displaced by said nut and sleeve members on said axis such that said detent means and said socket means are engaged and to release said base and said tool turret to be free to rotate with respect to each other when said tool turret is axially displaced on said axis by said nut member and said sleeve member such that said detent means and said socket means are disengaged, and a drive shaft coaxially extending through said sleeve, connected to tool turret, and adapted for rotating said tool turret when said socket means and said detent means are disengaged.

9. The indexing turret of claim 8 which also comprises an actuator bar carried by said base for longitudinal sliding motion therein generally transverse to said axis, a generally transverse cross-slide on said actuator bar, and a follower block carried by said cross-slide and operably connected to said one member such that said one member is rotated by longitudinal movement of said actuator bar.

11. The indexing turret of claim 8 in which said detent means and said socket means comprises first and second racks in the Form of a ring each having a plurality of integral, generally radially and axially extending and circumferentially spaced teeth in one face thereof with the teeth of said racks being adapted to mesh with each other when urged into firm engagement to lock said tool turret and said base against rotation with respect to each other.