Claims:We Claim:
1. An automated chuck changing mechanism for a vertical turret lathe machine, comprising:
a primary spindle (101);
a first chuck (103) engaging with the primary spindle (101) for machining a first work piece;
characterized in that
at least one secondary spindle (102);
a second chuck (104) engaging with the secondary spindle (102) for loading a second work piece during the machining of the first work piece;
a clamping system provided on the primary spindle (101) and the secondary spindle (102) for automatically engaging and disengaging the first chuck (103) from the primary spindle (101) and the second chuck (104) from the secondary spindle (102); and
a coupling mechanism ((105a, 106a), (105b, 106b)) provided for securely positioning the first chuck (103) with the primary spindle (101) and the second chuck (104) with the secondary spindle (102);
2. The mechanism as claimed in claim 1, wherein the clamping system including:
a hydraulic clamping cylinder assembly (416) activated by pressurized hydraulic oil;
a draw bar (415) operatively connected to a piston of the hydraulic clamping cylinder assembly (416);
a draw bolt (420) operatively connected to the draw bar (415);
a split collet (419) placed on a stepped groove (420a) provided on the draw bolt (420);
a guide sleeve (418) mounted on the spindle (101, 102) for enclosing the split collet (419); and
the hydraulic clamping cylinder assembly (416) actuating upwards movement and downwards movement of the draw bar (415) and the draw bolt (420) relative to the spindle (101,102) and the guide sleeve (418); and
wherein the upwards movement opening the split collet (419) radially outward and downwards movement closing the split collet (419) radially inward.
3. The mechanism as claimed in claim 2, wherein a hollow pull stud (417) is mounted on a cylinder (403) of the chuck (103, 104);
the split collet (419) clamping to the hollow pull stud (417) during the radially inward closing, thereby engaging the chuck (103,104) with the spindle (101,102); and
the split collet (419) releasing the hollow pull stud (417) during the radially outward opening, thereby disengaging the chuck (103,104) from the spindle (101,102).
4. The mechanism as claimed in claim 2, wherein the guide sleeve (418) including a circumferential step (418a) for facilitating radially outward opening of the split collet (419) during the upward movement.
5. The mechanism as claimed in claim 2, wherein the draw bar (415) operatively connected to the draw bolt (420) and the piston through a threaded joint.
6. The mechanism as claimed in claim 1, wherein the coupling mechanism ((105a, 106a), (105b, 106b)) including a hirth coupling (105a, 106a) mounted on a cylinder (403) of the chuck (103, 104) engaging with a hirth coupling (105b, 106b) fixed to the spindle (101, 102) for securely positioning the chuck (103, 104) relative to the spindle (101, 102).
7. The mechanism as claimed in claim 1, wherein an interchange mechanism provided for interchanging the first chuck (103) and the second chuck (104) relative to the primary spindle (101) and the secondary spindle (102), the interchange mechanism including:
an indexer arm (110) connecting the first chuck (103) and the second chuck (104);
a lifting mechanism (111) lifting the indexer arm (110) with the first chuck (103) and the second chuck (104); and
an indexing mechanism (109) rotating the indexer arm (110) for rotating the first chuck (103) and the second chuck (104) relative to the primary spindle (101) and the secondary spindle (102).
8. The mechanism as claimed in claim 7, wherein the indexer arm (110) including locator pins (602a, 602b) for engaging with locators (601a, 601b) provided on a cylinder (403) of the chuck (103, 104);
the lifting mechanism (111) lifting the indexer arm (110) for engaging the locator pin (602a, 602b) to the locator (601a, 601b), thereby engaging the first chuck (103) and the second chuck (104) to the indexer arm (110);
the lifting mechanism (111) lifting the first chuck (103) and the second chuck (104) through the indexer arm (110); and
the lifting mechanism (111) lowering the indexer arm (110) for disengaging the locator pin (602a, 602b) from the locator (601a, 601b), thereby disengaging the first chuck (103) and the second chuck (104) from the indexer arm (110) for facilitating movement of the chuck with the spindle.
9. The mechanism as claimed in claim, wherein the first chuck (103) and the second chuck (104) are manually operated.
10. The mechanism as claimed in claim 1, wherein the first chuck (103) and the second chuck (104) are hydraulically operated for automated clamping of jaws of the chuck (103, 104) to the work piece.
11. The mechanism as claimed in claim 1, wherein a hydraulic mechanism provided for actuating the first chuck (103), the hydraulic mechanism including:
a rotary distributer (411) for providing pressurized hydraulic oil to a cylinder (403) provided on the chuck (103, 104) through auto couplers ((406a, 406b), (407, 407b)) and pipes (405a, 405b for automated clamping of the first work piece.
12. The mechanism as claimed in claim 8, wherein indexer arm (100) rotatable 180 degrees for placing the second chuck (104) corresponding to the primary spindle (101) for machining the second work piece.
13. A method for an automated chuck changing mechanism in vertical turret lathe machines, comprising the steps of:
disengaging (1001) a first chuck with a machined first work piece from a primary spindle and a second chuck with an un-machined second work piece from a secondary spindle, by a clamping mechanism;
lifting (1002) an indexer arm connected to the first chuck and the second chuck upwards, relative to the primary spindle and the secondary spindle, by a lifting mechanism;
indexing (1003) the indexer arm connected to the first chuck and the second chuck relative to the primary spindle and the secondary spindle, by an indexing mechanism;
lowering (1004) the indexer arm with the first chuck and the second chuck, by the lifting mechanism;
positioning the second chuck with the primary spindle and the first chuck with the secondary spindle, by a coupling mechanism; and
engaging (1005) the second chuck with the primary spindle for machining the second work piece, by the clamping mechanism.
, Description:AN AUTOMATED CHUCK CHANGING MECHANISM
FIELD
[0001] The embodiments herein generally relate to the field of chucks. More particularly, the disclosure relates to a chuck changing mechanism.
BACKGROUND AND PRIOR ART
[0002] Chuck is an essential component in lathe machines for holding the rotating work piece. Vertical turret Lathe machines (VTLs) are general purpose machines for machining heavy parts. Generally, VTLs are equipped with a single chuck, which holds the part for being machined.
[0003] However, since the parts being machined are heavy and larger in size, significant time is consumed for loading and unloading the part to the chuck. The time includes unloading of the machined part from chuck, cleaning of the chuck and loading a new part. Generally, the time taken for loading the new part is between 3 to 5 minutes for forged and cast parts, subject to efficiency of the person operating the machine. Further, during the loading of the new part, the machine is idle without providing any output.
[0004] Conventionally, a typical forged part to be machined takes around 7 to 10 minutes of machining time, wherein during the machining the machine provides output. Hence, this implies that during the loading of the new part, the machine is idle for around 30% to 40% of the operational time.
[0005] Also, there are parts that require to be dialed for radial runout, when clamped to the chuck, before machining. The dialing and setting requires considerable amount of time and moreover the part should not be disturbed after setting.
[0006] Currently, designs of chuck changing mechanisms are present, however the existing designs of chuck changing are confined to specific applications, work pieces and specific chucks.
[0007] Therefore, there is a need for a chuck changing mechanism, for increasing efficiency and productivity of a vertical turret lathe machine. Moreover, there is a need for a chuck changing mechanism of a vertical lathe machine to eliminate machine idle time wherein the chuck changing is performed with the part rigidly held to the chuck.
OBJECTS
[0001] Some of the objects of the present disclosure are described herein below:
[0002] The main objective of the present disclosure is to provide a chuck changing mechanism for a vertical turret lathe.
[0003] Another objective of the present disclosure is to provide an automated clamping mechanism for the chuck changing of a vertical turret lathe.
[0004] Still another objective of the present disclosure is to provide an automated chuck changing mechanism wherein the part is held rigidly to the chuck during chuck changing.
[0005] Yet another objective of the present disclosure is to provide a chuck changing mechanism suitable for any type of hydraulically operated chuck or manually operated chuck.
[0006] Still another objective of the present disclosure is to provide a chuck changing mechanism for hydraulically operated chucks or manually operated chucks of a vertical turret lathe.
[0007] The other objectives and advantages of the present disclosure will be apparent from the following description when read in conjunction with the accompanying drawings, which are incorporated for illustration of preferred embodiments of the present disclosure and are not intended to limit the scope thereof.
SUMMARY
[0008] In view of the foregoing, an embodiment herein provides an automated chuck changing mechanism.
[0009] In accordance with an embodiment, the mechanism for a vertical turret lathe machine comprises a primary spindle, at least one secondary spindle, a first chuck engaging with the primary spindle for machining a first work piece and a second chuck engaging with the secondary spindle for loading a second work piece during the machining of the first work piece. A clamping system is provided on the primary spindle and the secondary spindle for automatically engaging and disengaging the first chuck from the primary spindle and the second chuck from the secondary spindle and a coupling mechanism provided for securely positioning the first chuck with the primary spindle and the second chuck with the secondary spindle.
[00010] In accordance with an embodiment, the clamping system includes a hydraulic clamping cylinder and piston assembly activated by pressurized hydraulic oil, a draw bar operatively connected to a piston of the hydraulic clamping cylinder and piston assembly, a draw bolt operatively connected to the draw bar, a split collet placed on a stepped groove provided on the draw bolt, a guide sleeve mounted on the spindle for enclosing the split collet and the hydraulic clamping piston and cylinder assembly actuating upwards movement and downwards movement of the draw bar and the draw bolt relative to the spindle and the guide sleeve. The upwards movement of the draw bar and the draw bolt opens the split collet radially outward and downwards movement of the draw bar and the draw bolt closes the split collet radially inward.
[00011] In an embodiment, a hollow pull stud is mounted on a cylinder of the chuck. The split collet clamps to the hollow pull stud during the radially inward closing, thereby engaging the chuck with the spindle. The split collet release the hollow pull stud during the radially outward opening, thereby disengaging the chuck from the spindle.
[00012] In an embodiment, the guide sleeve includes a circumferential step for facilitating radially outward opening of the split collet during the upward movement.
[00013] In an embodiment, the draw bar is operatively connected to the draw bolt and the piston through a threaded joint.
[00014] In an embodiment, the coupling mechanism includes a hirth coupling mounted on a cylinder of the chuck and a hirth coupling fixed to the spindle. The hirth coupling mounted on the cylinder is engaged to the hirth coupling fixed to the spindle for securely positioning the chuck relative to the spindle.
[00015] In an embodiment, an interchange mechanism is provided for interchanging the first chuck and the second chuck relative to the primary spindle and the secondary spindle. The interchange mechanism includes an indexer arm connecting the first chuck and the second chuck, a lifting mechanism lifting the first chuck and the second chuck through the indexer arm and an indexing mechanism rotating the indexer arm for rotating the first chuck and the second chuck relative to the primary spindle and the secondary spindle.
[00016] In an embodiment, the indexer arm includes locator pins for engaging with locators provided on a cylinder of the chuck, the lifting mechanism lifts the indexer arm for engaging the locator pins to the locators, thereby engaging the first chuck and the second chuck to the indexer arm and the lifting mechanism lifts the first chuck and the second chuck through the indexer arm simultaneously. The lifting mechanism lowers the indexer arm for disengaging the locator pins from the locators thereby disengaging the first chuck and the second chuck from the indexer arm for facilitating free rotation of the chuck along with respective spindles. In an embodiment, the indexer arm is rotatable 180 degrees for placing the second chuck corresponding to the primary spindle for machining the second work piece.
[00017] In an embodiment, the first chuck and the second chuck are hydraulically operated for automated clamping of jaws of the chuck to the work piece.
[00018] In an embodiment, a hydraulic mechanism provided for actuating the first chuck, the hydraulic mechanism including a rotary distributer for providing pressurized hydraulic oil to a cylinder provided in the chuck through auto couplers and pipes for automated clamping of the first work piece.
[00019] In accordance with an embodiment, a method for an automated chuck changing mechanism in vertical turret lathe machines, comprises the steps of engaging a first chuck with a primary spindle for machining a first work piece, engaging a second chuck with a secondary spindle for loading a second work piece during the machining of the first work piece, disengaging the first chuck with the machined first work piece from the primary spindle and the second chuck with the un-machined second work piece from the secondary spindle, by a clamping mechanism, lifting an indexer arm connected to the first chuck and the second chuck upwards, relative to the primary spindle and the secondary spindle, by a lifting mechanism, indexing the indexer arm connected to the first chuck and the second chuck relative to the primary spindle and the secondary spindle, by an indexing mechanism, lowering the indexer arm with the first chuck and the second chuck, by the lifting mechanism, positioning the second chuck with the primary spindle and the first chuck with the secondary spindle, by a coupling mechanism and engaging the second chuck with the primary spindle for machining the second work piece, by the clamping mechanism.
[00020] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[00021] The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
[00022] Fig. 1 illustrates a cross-sectional view of an automated chuck changing mechanism provided in a vertical turret lathe, according to an embodiment herein;
[00023] Fig.2 illustrates a top view of the chuck changing mechanism, according to an embodiment herein;
[00024] Fig.3 illustrates a perspective view of the chuck changing mechanism, according to an embodiment herein;
[00025] Fig. 4a illustrates a detailed cross-sectional view ‘A’ of the chuck changing mechanism of Fig. 1, according to an embodiment herein;
[00026] Fig. 4b illustrates a detailed view ‘E’ of the chuck changing mechanism of Fig. 4a, according to an embodiment herein;
[00027] Fig. 4c illustrates a cross-sectional view of the hydraulic clamping cylinder and rotary distributor of the chuck changing mechanism, according to an embodiment herein;
[00028] Fig. 5 illustrates a detailed view of a de-clamped position of the chuck changing mechanism, according to an embodiment herein;
[00029] Fig. 6a illustrates a detailed view ‘C’ of the cross-section of the chuck changing mechanism of Fig. 1, according to an embodiment herein;
[00030] Fig. 6b illustrates an engaged position of the indexer arm with the chuck of Fig. 6a, according to an embodiment herein;
[00031] Fig. 7 illustrates a cross-sectional view of the chuck changing mechanism in a disengaged position, according to an embodiment herein;
[00032] Fig. 8a illustrates a detailed cross-sectional view of ‘B’ of the chuck changing mechanism of Fig. 7, according to an embodiment herein;
[00033] Fig. 8b illustrates a detailed view ‘D’ of the cross-section of the chuck changing mechanism of Fig. 8a;
[00034] Fig. 9a illustrates a hollow pull stud, Fig, 9b illustrates a split collet and Fig. 9c illustrates a draw bolt of the chuck changing mechanism according to an embodiment herein; and
[00035] Fig. 10 illustrates a flow chart of a method for automated chuck changing mechanism of a vertical turret lathe machine, according to an embodiment herein.

[00036] LIST OF NUMERALS
101 - Primary spindle
102 - Secondary spindle
103 - First chuck
104 - Second chuck
105a, 105b, 106a, 106b - Hirth coupling
109 - Indexing mechanism
110 - Indexer arm
111 - Lifting mechanism
301 - Machine bed
401 - Piston
402 - Face plate
403 - Cylinder
403a - Bottom portion of the cylinder
405a, 405b - Pipes
405aa, 405bb - Bottom end of the pipes
406a, 406b, 407a, 407b - Auto couplers
408 - Housing
409 - Adaptor
413 - Casing
414 - Rotary distributor
415 - Draw bar
416 - Hydraulic clamping cylinder assembly
417 - Hollow pull stud
418 - Guide sleeve
418a - Circumferential step
419 - Split collet
420 - Draw bolt
420a - Stepped groove
601a, 601b - Locators
602a, 602b - Locator pins

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[00037] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[00038] As mentioned above, there is a need for a chuck changing mechanism, to increase efficiency and productivity of a vertical turret lathe machine. In particular, there is a need for a chuck changing mechanism of a vertical lathe machine to eliminate machine idle time. The embodiments herein achieve this by providing “An automated chuck changing mechanism”. Referring now to the drawings, and more particularly to Fig.1 through Fig.10, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[00039] Fig. 1 illustrates a cross-sectional view of an automated chuck changing mechanism provided in a vertical turret lathe. In an embodiment, the chuck changing mechanism includes a primary spindle 101, at least one secondary spindle 102, clamping mechanism (not shown in figure) and a coupling mechanism (105a, 106a), (105b, 106b). The first chuck 103 and the second chuck 104 are configured for being engaged and disengaged from the primary spindle 101 and the secondary spindle 102.
[00040] In an embodiment, any type of chuck is capable of being engaged to the first spindle 101 and the second spindle 102.
[00041] In an embodiment, a first work piece is mounted on the first chuck 103 for performing machining of the work piece through a tool mounted to a turret. In an embodiment, the first chuck 103 is engaged with the primary spindle 101 through the clamping mechanism. Position of the first chuck 103 is fixed relative to the primary spindle, by the coupling mechanism 105a, 106a.
[00042] In an embodiment, a second work piece is loaded on the second chuck 104 while the first work piece is being machined in the primary chuck 103. The second chuck 104 is engaged with the secondary spindle 102, through the clamping mechanism. Position of the second chuck 104 is fixed relative to the secondary spindle 102, by the coupling mechanism 105b, 106b.
[00043] In an embodiment, an interchange mechanism is provided for interchanging the first chuck 103 and the second chuck 104 relative to the first spindle 101 and the second spindle 102. In an embodiment, the interchange mechanism includes an indexing mechanism 109, an indexer arm 110 and a lifting mechanism 111. In an embodiment, one end of the indexer arm 110 is connected to the first chuck 103 and another end of the indexer arm 110 is connected to the second chuck 104. Upward movement of the lifting mechanism lifts the indexer arm, thereby lifting the first chuck 103 and the second chuck 104 from respective spindles. The indexing mechanism 109 rotates the indexer arm 110, thereby rotating the first chuck 103 and the second chuck 104 relative to the primary spindle 101 and the secondary spindle 102. The indexing mechanism 109 indexes the indexer arm 110 by 180 degrees for placing the second chuck 104 with the primary spindle 101 to perform machining of the second work piece loaded on the second chuck.
[00044] In an embodiment, the lifting mechanism is a conventional lifting mechanism and the indexing mechanism is a conventional indexing mechanism.
[00045] Fig.2 illustrates a top view of the chuck changing mechanism. In an embodiment, the interchange mechanism includes an indexing mechanism 109, the indexer arm 110, the first chuck 103 and the second chuck 104. The rotation of the indexer arm by 180 degrees positions the second chuck 104 with the primary spindle 101 for performing machining of the second work piece and the primary chuck 103 with the secondary spindle 102 for unloading of the machined first work piece.
[00046] Fig. 3 illustrates a perspective view of the chuck changing mechanism. The first chuck 103 is engaged to the primary spindle (not seen in figure) that is mounted to a machine bed 301 and the second chuck 104 is engaged to the secondary spindle 102. The interchange mechanism is mounted on the machine base 301 at 302. A machine enclosure (not seen in figure) is provided for enclosing the primary spindle 101 and the chuck engaged with the primary spindle to protect human operator from swarf generated during machining. The secondary spindle 102 and the chuck engaged with the secondary spindle are provided outside the machine enclosure.
[00047] Fig. 4a illustrates a detailed cross-sectional view ‘A’ of the chuck changing mechanism of Fig. 1.
[00048] The cross-sectional view ‘A’ includes the first chuck 103 engaged with the primary spindle 101. The first chuck 103 is engaged with the primary spindle 101 through a clamping mechanism. The coupling mechanism 105a, 106a is provided for securely positioning the first chuck 103 relative to the primary spindle 101, for repeatability and positional accuracy during interchanging of the chucks. In an embodiment, the coupling mechanism (105a, 106a) includes a hirth coupling 105a, engaging with a hirth coupling 106a.
[00049] The first chuck 103 is mounted to a face plate 402. In an embodiment, the first chuck 103 and the second chuck 104 are hydraulically operated chucks wherein the jaws automatically clamp and de-clamp the work piece. In an embodiment, the primary spindle 101 includes a hydraulic mechanism. The hydraulic mechanism includes a rotary distributor 414 for distributing hydraulic oil through the hydraulic mechanism. The rotary distributor 414 distributes the oil through pipes 405a, 405b. A casing 413 is provided for enclosing the pipes 405a and 405b. The pipe 405a is connected to an auto coupler 406a and the pipe 405b is connected to an auto coupler 406b. A housing 408 is provided for encasing the auto couplers 406a and 406b. Auto couplers 407a mates with the auto coupler 406a and an auto coupler 407b mates with the auto coupler 406b. The hydraulic oil from the pipes 405a, 405b flow through the auto couplers 406a, 406b, 407a, 407b.
[00050] An adapter 409 is provided for housing the auto couplers 407a, 407b and engaging with a bottom portion of a cylinder 403 in the chuck 103. A piston 401 is housed inside the cylinder 403, wherein the piston 401 is movable relative to the cylinder 403. In an embodiment, the piston 401 is connected to movable components of the chuck 103, using fastening components including but not limited to screws.
[00051] In an embodiment, the hydraulic oil distributed by the rotary distributer 414 is supplied through the pipe 405a, the auto couplers 406a, 407a to a bottom of the piston 401 and supplied through the pipe 405b, the auto couplers 406b, 407b to a top of the piston 401. The pressurised hydraulic oil supply enables upward or downward movement of the piston 401 relative to the cylinder 403. The upward and downward movement of the piston moves jaws of the chuck radially outward and radially inward for automated clamping or declamping of the work piece to the chuck.
[00052] In an embodiment, a draw bar 415 and a hydraulic clamping cylinder assembly 416 are provided in the primary spindle 101. The rotary distributor 414 supplies pressurised hydraulic oil to the hydraulic clamping cylinder assembly 416.
[00053] Fig. 4b illustrates a detailed view “E” of Fig. 4a, a clamped position of the clamping mechanism of chuck changing mechanism. In an embodiment, the clamping mechanism is provided in the primary spindle 101 and the secondary spindle 102.
[00054] The clamping mechanism includes a hollow pull stud 417, a guide sleeve 418, a split collet 419, a draw bolt 420, a draw bar 415 and a hydraulic clamping cylinder assembly 416. The hollow pull stud 417 is mounted on a bottom 403a of the cylinder 403. The guide sleeve 418 is mounted on the primary spindle 101. The guide sleeve 418 includes a circumferential step 418a extending radially outward. The draw bar 415 is provided around the casing 413 of the pipes 405a, 405b and the draw bolt 420 is connected to an upper end of the draw bar 415.
[00055] In an embodiment, the draw bolt 420 is connected through a threaded joint with the draw bar 415, wherein external threads are provided on the draw bar 415 for mating with internal threads provided on the draw bolt 420. Upward and downward movement of the drawbar 415 moves the draw bolt 420 relative to the primary spindle 101 and/or secondary spindle 102.
[00056] In an embodiment, the draw bolt 420 includes a circumferential stepped groove 420a provided radially inward for housing the split collet 419. The split collet 419 is placed in the stepped groove 420a and is partially constraint between the draw bolt 420 and the guide sleeve 418. In an embodiment, the circumferential step 418a provided on the guide sleeve 418 allows radial outward opening of the split collet 419.
[00057] A bottom end of the draw bar 415 (not shown) is connected to a piston of the hydraulic clamping cylinder assembly 416. In an embodiment, the draw bar 415 is connected to the piston through a threaded joint. The rotary distributor 414 transmits pressurized hydraulic oil into cylinder of the hydraulic clamping cylinder assembly 416. The pressurized hydraulic oil activates movement of the piston thereby actuating movement of the draw bar 415 for automated clamping of the first chuck 103 and second chuck 104 to the primary spindle 101 and the secondary spindle 102.
[00058] In an embodiment, downward movement of the piston in the hydraulic cylinder assembly 416 pulls the draw bar 415 downwards relative to the primary spindle 101 and/or secondary spindle 102. The downward movement of the draw bar 415 pulls the draw bolt 420 downwards. The split collet 419 connected to the draw bolt 420 is pulled downwards and closed radially inwards by the draw bolt 420, wherein the split collet 419 is pushed from the radially outward step 418a into an area within the guide sleeve 418. The split collet 419 closes radially inward and latches to an outer surface of the hollow pull stud 417, thereby clamping the hollow pull stud 417. The clamping of the hollow pull stud 417 with the split collet 419 firmly engages the chuck 103/104 with the spindle 101/102 through the hirth couplings (105a, 106a), (105b, 106b).
[00059] In an embodiment, in the clamped position includes the auto couplers 407a, 407b mating with the auto couplers 406a, 406b. The mating of the auto couplers (407a, 407b) with (406a, 406b) establishes connection between the rotary distributor 414 and the primary chuck 103, thereby allowing flow of pressurized hydraulic oil to the cylinder 403 for actuating jaws of the primary chuck 103 for clamping the work piece.
[00060] Fig. 4c illustrates a cross-sectional view of the hydraulic clamping cylinder and rotary distributor of the chuck changing mechanism. A bottom end 405aa of the pipe 405a and a bottom end 405bb of the pipe 405b are connected to the rotary distributor 414. The draw bar 415 is connected to the piston of the hydraulic clamping cylinder assembly 416 by a threaded joint. The rotary distributor 414 actuates the draw bar 415 by supplying oil to the hydraulic clamping cylinder 416 and pushing the piston for engaging and disengaging the chuck 103/104 from the spindle 101/ 102. The rotary distributor 414 actuates the jaws of the chuck 103 by supplying oil to the cylinder 403 through the auto couplers 407a, 407b.
[00061] Fig. 5 illustrates a detailed view of a declamped position of the chuck changing mechanism. In an embodiment, the pressurized hydraulic oil from the rotary distributor to the cylinder of the hydraulic clamping cylinder assembly 416 activates the piston thereby pushing the draw bar 415, moving the draw bolt 420 and opening the split collet 419 radially outwardly in the circumferential step 418a of the guide sleeve 418. The radially outward opening of the split collet 419 releases the hollow pull stud 417 mounted to the bottom of the cylinder 403 of the chuck 103/104 from the split collet 419.
[00062] Fig. 6a illustrates a detailed view ‘C’ of the cross-section of the chuck changing mechanism of Fig. 1. In an embodiment, the first chuck 103 includes the cylinder 403, the piston 401, the hirth coupling 105a mounted on the cylinder 403 and the adaptor 409 housing the auto couplers 407a, 407b. The split collet 415 is mounted on the bottom of the cylinder 403.
[00063] The chuck 103 is disconnected from the indexer arm 110. In an embodiment, a locator 601a and a locator 601b are mounted on the cylinder body 403 of the first chuck 103 and the second chuck 104. The indexer arm 110 includes a locator pin 602a for engaging with the locator 601a and a locator pin 602b for engaging with the locator 601b.
[00064] Fig. 6b illustrates an engaged position of the indexer arm with the chuck of Fig. 6a. The first chuck 103 is engaged with the indexer arm 110. In an embodiment, the locator pin 602a is engaged with the locator 601a and the locator pin 602b is engaged with the locator 601b. The lifting mechanism 111 lifts the indexer arm 110, wherein the upward movement of the indexer arm 110 engages the locator pins 602a, 602b engages to the locators 601a, 601b, thereby engaging the indexer arm 110 to the chuck 103, 104. Further upward lifting of the indexer arm 110 by the lifting system 111, disengages the first chuck 103 and the second chuck 104 from the primary spindle 101 and the secondary spindle 102.
[00065] In an embodiment, after lifting first chuck 103 and the second chuck 104 through the indexer arm, the indexing mechanism 109 indexes the first chuck 103 and the second chuck 104 relative to the primary spindle 101 and the secondary spindle 102. Next, the lifting mechanism lowers the indexer arm 110. The indexer arm 110 engaged to the first chuck and the second chuck through the locators 601a 601b and the locator pins 602a, 602b, lowers the first chuck 103 and the second chuck 104 for engaging with the primary spindle 101 and the secondary spindle 102. The lifting mechanism 111 lowers the indexer arm 110 further, for disengaging the locator pins 602a, 602b from the locators 601a, 601b, thereby facilitating relative motion of the first chuck 103 and the second chuck 104 with respect to the indexer arm 110. The relative motion enables machining of the work piece mounted on the chuck through the primary spindle 101.
[00066] Fig.7 illustrates a cross-sectional view of the chuck changing mechanism in a disengaged and lifted position. In an embodiment, the clamping mechanism disengages the first chuck 103 from the primary spindle 101 and the second chuck 104 from the secondary spindle 102, after the machining of the first work piece mounted on the first chuck 103 using the primary spindle 101.
[00067] The lifting mechanism 111 lifts the indexer arm 110 for lifting the first chuck 103 and the second chuck 104 upwards relative to the primary spindle 101 and the secondary spindle 102. The indexing mechanism 109 indexes the indexer arm 110 for rotating the first chuck 103 and the second chuck 104 relative to the primary spindle 101 and the secondary spindle 102, and placing the second chuck 104 along the primary spindle 101 for performing machining of the second work piece.
[00068] Fig. 8a illustrates a detailed cross-sectional view of ‘B’ of the chuck changing mechanism of Fig. 7. The cross-sectional view ‘B’ shows a disengaged position of the first chuck 103 from the primary spindle 101. The first chuck 103 is disengaged from the primary spindle 101, by the clamping mechanism. The hirth coupling 105a is mounted on the cylinder 403, and the hirth coupling 106a is fixed to the primary spindle 101. The auto couplers 407a, 407b are separated from the auto couplers 406a, 406b, thereby stopping the flow of hydraulic oil from the rotary distributor 414 to the cylinder 403 of the first chuck 101.
[00069] Fig. 8b illustrates a detailed view of ‘D’ of the cross-section of Fig. 8a of the chuck changing mechanism. In an embodiment, the chuck 103, 104 is lifted up from the spindle 101, 102. The split collet 419 is opened radially outward in the circumferential step 418a provided on the guide sleeve 416.
[00070] Fig. 9a illustrates a hollow pull stud, Fig. 9b illustrates a split collet and Fig. 9c illustrates a draw bolt of the chuck changing mechanism. The split collet 419 clamps and releases the hollow pull stud 417 mounted on the chuck 103/104 for engaging and disengaging the chuck 103/104 from the spindle 101/ 102.
[00071] Fig. 10 illustrates a flow chart of a method for automated chuck changing mechanism of a vertical turret lathe machine. After machining of the first work piece on the primary spindle, the method includes the steps of disengaging (1001) the first chuck from the primary spindle and the second chuck from the secondary spindle, by the clamping mechanism. The clamping mechanism including radial outward opening of a split collet provided in the primary spindle and the secondary spindle for releasing a hollow pull stud attached to the first chuck and second chuck.
[00072] Next, lifting (1002) the indexer arm with the first chuck and the second chuck from the primary spindle and the secondary spindle, by the lifting mechanism. The locator pins provided on the indexer arm are engaged to the locators provided on the first chuck and the second chuck, by a lifting mechanism for secure holding of the chucks.
[00073] Then, indexing (1003) the indexer arm connected to the first chuck and the second chuck relative to the primary spindle and the secondary spindle, by an indexing mechanism. Indexing the indexer arm to 180°, for positioning the first chuck with the machined work piece above the secondary spindle and the second chuck with the work piece to be machined above the primary spindle.
[00074] Lowering (1004) the indexer arm with the first chuck and the second chuck relative to the primary spindle and the secondary spindle, by the lifting mechanism. The second chuck and the first chuck are engaged with the primary spindle and the secondary spindle, by the coupling mechanism including the hirth couplings for ensuring positioning accuracy of the chuck relative to the spindle. Next, lowering the indexer arm for disconnecting the indexer arm from the first chuck and the second chuck, by the lifting mechanism. The locator pins provided on the indexer arm are disengaged from the locators provided on the first chuck and the second chuck.
[00075] Finally, engaging (1005) the second chuck with the primary spindle for machining the second work piece and the first chuck with the secondary spindle, by the clamping mechanism. The rotary distributor activates the hydraulic clamping cylinder assembly for actuating the clamping of the split collet with the hollow pull stud of the chuck. The chuck is securely clamped on to the spindle and the machine is ready for machining the second work piece.
[00076] The machined first work piece clamped to the first chuck on the secondary spindle is now unclamped from the first chuck. During the machining of the second work piece, the first workpiece is removed and the chuck is cleaned. Next work piece to be machined is loaded and clamped to the first chuck.
[00077] A main advantage of the present disclosure is that the mechanism provides automated chuck changing for a vertical turret lathe machine.
[00078] Another advantage of the present disclosure is that the mechanism improves efficiency of a vertical turret lathe machine through automated chuck changing.
[00079] Still another advantage of the present disclosure is that the mechanism increases available production time of a vertical turret lathe machine.
[00080] Yet another advantage of the present disclosure is that the mechanism provides hydraulically automated clamping mechanism for engaging and disengaging the chuck to and from the spindle.
[00081] Still another advantage of the present disclosure is that the mechanism provides compatibility with any type of hydraulically operated chuck in a vertical turret lathe.
[00082] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.