Description: Automatic Dual Cutter Roller Sharpening Machine

4. FIELD OF INVENTION:

The Invention herein relates to a high-quality roller sharpening – all-in-one machine which ensures quality and accuracy of sharpening by the application of CNC controller and which prevents multi equipment application and ensure one setting finish for all the operations including Chasing, Milling and Lathe Work, enabling high speed of operations leading to reduced time and increased productivity. The invention includes single point inserts and Cutter to ensure less cutting force and better surface finish with longer life of cutting tool, machine as well as roller.

5. ADVANTAGE OF THE MACHINE USED FOR THIS PURPOSE:

I. Chasing:

a) Accuracy of profile / TPI
Level of accuracy: + 0.02/ 20 micron.
Advantage: Proper Meshing of Roller resulting better cutting of tea leaves.

b) Accuracy in depth of chasing
Level of accuracy: + 0.02/ 20 micron.
Advantage: Proper Depth of Chasing, resulting uniform clearance between the meshing rollers during cutting and ultimately better cutting of tea leaves.

c) Better quality of finish product.
Quality Level: Very high-quality finish, no buds and cutting chips on the cutting edge of the Roller.
Advantage: Fine finish of rollers ensures better cutting of tea leaves, no heat generation due to metal-to-metal friction and ultimately no loss in liquor quality of the finished Tea.
Application of Single Point insert, better cutting tool and better control on cutting speed and feed during metal cutting operation ensures superior quality of finish of the Rollers.

d) Minimum metal loss.
Advantage: Minimum metal cutting during grooving operation ensures longer life of expensive Stainless Steel material of rollers due to higher accuracy level in the depth of cut on the rollers.

e) Minimum time taking operation

Advantage:
Very high productivity with less manpower.
• A complete automatic operation which ensures zero manpower involvement and ultimately high level of accuracy and minimum operation time.
• Single setting of rollers for all the operations reduces setting time and ensures zero setting error.
• A high speed operating system ensures high surface finish / product quality.

f) Manpower saving
Advantage: High feed rate and spindle rpm ensures minimum operation time and ultimately saving in manpower. Application of high quality cutting tool / insert increases productivity, reduces power consumption, human involvement and ultimately saving in cost of roller sharpening.

II. Milling:

a) Dual Helical groove option
Level of accuracy: + 0.02/ 20 micron.

Advantage: High level of accuracy and uniform depth of cut ensures high quality milling operation resulting to better cutting of tea leaves.
Machine can produce any number of helical grooves (no. of helix) in 360 deg. rotation of rollers. Machine can also produce any linear movement of carriage (lead) for any angle of rotation of the roller.

b) Feed control
Advantage: Cutting speed and movement of tool post can be adjusted as per requirement for different type of jobs (different material of construction and diameter of roller).

c) Cutter speed control
Advantage: Cutter spindle speed is adjustable by variable frequency drive and as per the hardness of segments, we can adjust different type of speed of the spindle. By this operation chattering marks on the helical grooves will be less, resulting good cutting and proper output of tea leaves.

d) Minimum time taking operation
Advantage: Very high productivity with less manpower.
• A complete automatic operation which ensures zero manpower involvement and ultimately high level of accuracy and minimum operation time.
• Single setting of rollers for all the operations reduces setting time and ensures zero setting error.
• A high speed operating system ensures high surface finish / product quality.

III. Lathe Operations:
Advantage: Any type of lathe operation like turning, facing, boring, threading, taper turning, etc. with different rpm and feed as required for the application can be done automatically.

6. BACKGROUND ART OF THE INVENTION:

Different types of machines have been used for the sharpening of CTC rollers in tea industries. The chasing groove is cut by a chasing machine, called a 'chaser,' and the milling groove is cut by a 'milling cutter.' The chasers and milling cutters also need to be sharpened during their use, a task that requires a 'tool and cutter grinder.' To check the accuracy of sharpening, a 'roller checking jig' is also needed. Thus, a typical set of sharpening equipment comprises the following: a chasing lathe machine, milling lathe machine, tool and cutter grinder, and roller checking jig. A combination of Milling-cum-Manual chasing, Auto Chasing & Auto Milling Machine - is also available. The initial capital expenditure involved in setting up a workshop is lower if a combination machine is used, but the use of this machine has the following disadvantages.

• During the milling and chasing operation, the saddle moves to and fro, a movement that takes place many more times during the milling operation than during the chasing operation. This repeated motion at high-speed causes excessive wear and tear on the mating slides and threads, thereby developing a 'play' which results in a chatter-finish chased groove (where vibration adversely affects the finish).

• Rollers cannot be meshed because of pitch errors caused by excessive play between lead screw and nut.

• Two operators are required to chase a roller: one to feed and retract the chaser onto the roller, the other for indexing.

• The Chasing Lathe: The purpose of this machine is to provide the chasing groove on the CTC roller. The chasing groove is perpendicular to the axis of the CTC roller. To obtain this groove, the machine uses a chaser as the tool. The chasing groove may have a U or a V profile, which is obtained by using a U or a V profile chaser.
The chasing operation requires a very skilled lathe operator, and the machine should be extremely sturdy as, at any given time, several teeth of a chasing tool are cutting into the roller, resulting in a heavy load being placed on the various components (the tool holder, saddle, cross slide, etc.). A lathe not suitably designed for heavy loads will lead to vibration and chatter marks on the roller - resulting in poor CTC Tea manufacturing.

• During high crop season in this agriculture industry, it becomes very difficult to ensure sharpening of rollers at regular intervals due to longer operational time in manual milling and grooving machine. It is also observed that due to manual errors and poor-quality engineering practices, the costly stainless-steel metal of the rollers gets wasted and ultimately reduce the life of roller. Overheating, vibration on CTC machine due to unmatched or poor finished rollers causes damage in the quality production of tea. It can only be reduced by implementation of automation by higher level of accuracy in sharpening of rollers.

• From our experience of running different Tea manufacturing unit, it was observed that the industry is suffering globally from many hurdles in respect to both engineering and skill. Automation and implementation of upgraded technology is the only solution to overcome the situation.

• We are under the impression that to make good tea we need good rollers.

Good Roller: A good roller is Precision in sharpening and machining the CTC roller surfaces and is the key to good CTC Tea manufacturing. Quality CTC teas cannot be made if roller teeth are worn out or damaged. It is, therefore, imperative that sharpening of segments is done precisely and on schedule. The linear speed difference between the rollers should be checked periodically to enhance the appearance of made tea and to improve the broken percentage. Difference in the diameter of rollers needs to different speed in rollers. To achieve 10:1 ratio, proper matching of equal diameter rollers is essential.
Even, helical grooves are formed along the circumference by a standard angular milling cutter. The teeth are formed by cutting circumferential grooves on the roller which has the helical grooves. Each tooth has two longitudinal characteristics, the shoulder and the back slope. The ratio of the length of the shoulder to the back slope projection is known as the profile or style ratio which influences quality. As a general rule, a style ratio of 1:1 will produce a grainy tea with lower dust percentage.
Good Tea: Mainly good teas are always carrying some character like bloom, Grainy,
Body, Brisk, Coloury, Flavoury, Bright, Creaming Down etc.

Faults in sharpening or poor quality in sharpening, which effects improper matching of CTC roller resulting at the time of tea manufacturing the excessive heat generation will be produced, due to that reason, loss and detonate desirable liquor characters, such as quality, flavour, briskness, Bloom, Bright, Body, Coloury, Grainy etc., may be completely lost due to faulty or poor roller sharpening.

7. OBJECT OF THE INVENTION:

To make good rollers we need good machine with better control on engineering application. To implement good engineering practice, we need a higher accuracy level which can be achieved by modern technical practice like computerized numeric control. The only machine which can perform the following operations by CNC for CTC roller sharpening including
i) Grooving, ii) Milling, iii) General lathe work.
Also, to ensure multipurpose work in a single machine with higher speed and minimum effort.

8. DEFINATION OF TERMS AS USED IN SPECIFICATION / INVENTION:
i. Roller sharpening:

In the manufacturing of CTC tea, it is extremely important to get the best cutting, curling and crushing the CTC rollers. With constant use during the manufacturing process, the CTC rollers become worn out, which affects in cutting, tearing and crushing, and, therefore, the end product to get the best out of the CTC machine, it becomes necessary to re-sharpen the CTC rollers.

ii. CTC:

The processing of tea has three stages (crush, tear, curl or cut, tear, curl), hence the name 'CTC' tea The CTC Machine was invented & Developed for the first time by Mr. McKercher in 1930.

iii. Circumferential:

The purpose of this operation is to provide the chasing groove on the CTC roller. The chasing groove is perpendicular to the axis of the CTC roller.

iv. Helical Groove:

Helical grooves are formed along the circumference by a standard angular milling cutter. The teeth are formed by cutting circumferential grooves on the roller which has the helical grooves.

v. CNC:
Computer numerical control (CNC) is a computer "controller" that reads G-code
and M-code commands and drives a machine tool, a powered mechanical device
typically used to fabricate components by the selective removal of material. CNC
does numerically directed interpolation of a cutting tool in the work envelope of a
machine.

vi. Lathe:
A lathe is a woodworking or metal working machine that rapidly turns the item to be lathed, A blade is then brought to the item in the case of wood a chisel can be used by hand and in the case of metal the blade is held in a specially made jig, the blade slices away metal until the round shape required is acquired. An example of an item that can be made on a lathe is a baseball bat.

vii. Good Tea:

Mainly good teas are always caring some character like bloom, Grainy, Body, Brisk, Colored, Flavory, Bright, Creaming Down etc.

viii. Inserts:

Insert made of “tungsten carbide” (as per required profile) with high cutting speed to ensure high quality finish. Almost all high-performance cutting tools use insert. There are several reasons for this. First, at the very high cutting speeds and feeds supported by these materials, the cutting tip can reach temperatures high enough to melt the brazing material holding it to the shank. Economics are also important; inserts are made symmetrically so that when the first cutting edge is dull, they can be rotated, presenting a fresh cutting edge. There are many types of inserts: some for roughing, some for finishing. Others are made for specialized jobs like cutting threads or grooves. The industry employs standardized nomenclature to describe inserts by shape, material, coating material, and size.

ix. Tea manufacturing:

Tea manufacturing is normally carried out in two ways, (i) CTC and (ii) orthodox. CTC refers to the Crush, Tear & Curl process where the withered green leaves are passed in-between two rollers rotating in opposite directions. Enzymatic action is higher in the CTC type of manufacture. Steps in CTC tea manufacture includes, withering of harvested crop, green leaf shifting, reconditioning, rolling, fermentation, drying, grading & sorting and packing.

x. High crop season:

Tea grows best in misty, rainy regions at altitudes of 2,000 to 7,000 feet in the tropics and lower elevations in temperate regions. Temperature alone influenced about 60-70 per cent of the crop productivity and the compounded effect of the relative humidity (maximum) accounted for 80 per cent of the total variance. Each climatic variable either alone or in combination-imposed stress on the plants and the compounded effect of change in climate not only affected the plant metabolism but also influenced the crop productivity.

xi. Milling cutter:

It is used for roller sharpening of Milling. It makes the helical grooves on the roller.
It is made from high carbon steel, grade M-15.

xii. Shoulder & Slope:

After completion the chasing and milling operation there is made one tooth and
within that tooth 3 parts are their tooth profile, solder, and slope. Each tooth has
two longitudinal characteristics, the shoulder, and the back slope. The ratio of the
length of the shoulder to the back slope projection is known as the profile or
style ratio which influences quality.

xiii. “Z” Axis, “X” Axis, “Y” Axis and ‘C’ Axis:

a) Primary Linear Axes
The “X” Axis, “Y” Axis and “Z” Axis produce linear motion in three mutually orthogonal directions.
b) Rotational Axes
The “C” axes produce angular motion (rotation). Typically, and “C” rotates around a line parallel to “Z”.

xiv. Cooling Pump:

High Pressure Cooling Pump helps the cutting of the metal and maintains
longer life of insert or tools.

xv. Segment:

grade (each segment is 2” width)

Grade Chemical Composition
(IS) Nickel % Chromium % Carbon % Hardness
304 8.00-12.00 18.00-20.00 0.08 max. 160 BHN
301 5.50-8.00 16.00-18.00 0.15 max. 180
201 3.50-5.50 16.00-18.00 0.15 max. 210

xvi. G-Code programming:

G-Code is the language used to control CNC machines. Your machine's CNC controller probably executes g-code, although there are other possibilities. Some machines with proprietary formats can also run g-code. It is the Lingua Franca (working language) of CNC.

xvii. Macro programming:

Advanced CNC macro programming techniques that result in unparalleled accuracy, flexible automation, and enhanced productivity. Step-by-step instructions begin with basic principles and gradually proceed in complexity. Specific descriptions and programming examples follow Fanuc's Custom Macro B language with reference to Fanuc 0i series controls. By the end of the book, you will be able to develop highly efficient programs that exploit the full potential of CNC machines.

xviii. Parameters:

Selection of parameters is given below:
• Diameter of roller = D
• Length of roller = L
• T.P.I / Thread per inch = T
• Depth of Cut = C
• No of chasing groove = G
• Spindle R.P.M = R

xix. Example:

Consideration:

Roller Diameter - 13”
Roller Length - 36”
T.P. I - 10 TPI
Depth of Cut - 1.625mm
No. of cycles of roller - 36 x 10 = 360 grooves.
Spindle R.P.M - 133 r.p.m

xx. Variable Frequency drive:

A Variable Frequency drive is a type of motor controller that drives an electric motor by varying the frequency and voltage supplied to the electric motor. Frequency (or hertz) is directly related to the motor’s speed (RPMs). In other words, the faster the frequency, the faster the RPMs go. If an application does not require an electric motor to run at full speed, the VFD can be used to ramp down the frequency and voltage to meet the requirements of the electric motor’s load. As the application’s motor speed requirements change, the VFD can simply turn up or down the motor speed to meet the speed requirement.

xxi. Ball screw:

Ball screw is a mechanical linear actuator rotational motion to linear motion with little friction A threaded shaft provides a helical raceway for ball bearing which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. They are made to close tolerances and are therefore suitable for use in situations in which high precision is necessary. The ball assembly acts as the nut while the threaded shaft is the screw. In contrast to conventional lead screw, ball-screws tend to be rather bulky, due to the need to have a mechanism to re-circulate the balls.

xxii. Limit switch:

Limit switch is a switch operated by the motion of a machine part or presence of an
object. They are used for control of a machine, as safety inters lock, or to count objects passing a point.

xxiii. MPG:

A circular hand wheel on a CNC machine that can move a tool incrementally along an axis. On some machines the MPG is known as the "handle." Keys located on the machine panel that allow the operator to move the tool incrementally along an axis.

Machine description:
Length: ……………………………………... 3345 mm
Width: ………………………………………… 1665 mm
Height: ………………………………………. 1980 mm
Weight: ………………………………………. 4500 kgs.

9. NATURE OF INVENTION:

The CTC machine essentially consists of two contra-rotating toothed rollers of equal diameters 216mm 8.5”, 9.5”, 13”. Depending upon the processing capacity required, rollers with different length are used i.e., 609.6mm (24”), 762mm (30”), 914.4mm (36”), 1066.8mm (42”), 1320.8mm (52”). A number of hollow segments of 2? width is mounted side by side on a mandrel to form a roller. Even spaced, helical grooves are formed along the circumference by a standard angular milling cutter. The teeth are formed by cutting circumferential grooves on the roller which has the helical grooves. Each tooth has two longitudinal characteristics, the shoulder and the back slope. The ratio of the length of the shoulder to the back slope projection is known as the profile or style ratio which influences quality.

One machine to execute all the CNC operation of CTC roller sharpening including Chasing, Milling and Lathe work, in one setting and with high accuracy level.

10. OPERATION DETAILS WITH FLOW CHART (FIGURE -01) GIVING BELOW:

Operational Metrology (Figure-02) giving below:

a) Circumferential chasing of grooves (Figure – 03)

• “Z” Axis, “X”, “Y” and ‘C’ Axis are operated by servo motors and servo drives synchronized by CNC controller.
• Adjustable cutting speed and feed which regulates automatically during change in roller specification like diameter, material of construction and length of roller.
• Use of single point insert made of “tungsten carbide” (as per required profile) with high cutting speed to ensure high quality finish.
• Use of 3 point cutting edge of insert ensures 3 times operational advantage.
• Automatic CNC mode of operation facility.
• Auto lubrication system for smooth movement of carriage and cross slide
• To execute the job in one setting by single point cutting tool which results in minimum cutting force, minimum heat generation and long life of rollers as well as machine.
• Use of high-pressure coolant pump to ensure no heat generation during cutting. It gives longer life of segment without any physical property of the metal due to heat.
• With G-Code and Macro programming in the controller automatically changes parameter like speed, feed, etc. based on change in specification of rollers. The change in software programme can be made to achieve any desired specification.
• Automatic change in parameters for new rollers and for sharpening.

b) Dual Helical Grooves on Segment Rollers: (figure -04)

• Synchronization of ‘Z’ Axis and ‘C’ Axis in respect to required lead and diameter of roller with the help of CNC controller.

• Adjustability in cutter RPM by Variable Frequency drive to match different specification of roller like (MOC) Metal of Construction and depth of cut.

• Implementation of software engineering to ensure zero error in depth of cut which is not possible in mechanical system.

• The system runs automatically ensuring feeding parameters (as displayed on screen) to ensure:
1) Diameter of roller
2) Length of roller
3) Lead of roller
4) Number of helical grooves
5) Depth of cut

• This is option in changing the parameters for new rollers and re-sharpening.
• MPG remote control arrangement to ensure better access of the operator during roller setting.
• Special type cutter holder for application of multipoint cutting teeth.
• Access to change the cutter shaft rpm from 100 to 140 for milling cutter and 800 to 1600 rpm for insert holder.

c) CNC General Lathe (figure -05)

• Any type of lathe operation like turning, facing, threading, taper turning, etc. with different rpm and feed as required for the application.


• All the operation will be controlled by CNC controller.
• Diameter of roller = D
• Length of roller = L
• T.P.I / Thread per inch = T
• Depth of Cut = C
• No of chasing groove = G
• Spindle R.P.M = R

1) Example:

Consideration:
Roller Diameter - 13”
Roller Length - 36”
T.P. I - 10 TPI
Depth of Cut - 1.625mm
No. of cycles of roller - 36 x 10 = 360 grooves.
Spindle R.P.M - 90 R.P.M
The machine with complete 360 cycles / grooves and will stop.

2) Machine completes the operation as follows – AUTOMATIC by CNC

• Homing
• Start Operation
• Complete Operation
• Stops Automatically

A) Initial Milling or Re-sharpening Milling of segment roller:

1) Loading and fixing the job (12) on head stock (19) and bearing based tailstock (09)– Manually
2) Alignment checking for parallelly of rollers center line with respect to machine – Manually
3) Fixing of Cutting Tool (10) – Manually
4) Selection of depth of cut, feed and R.P.M, length of job in CNC panel (46) – Manually.
5) Start operation from CNC panel (46) – manual.
6) For milling operation, parameters in CNC panel (46) – Manual
7) Selection of parameters (47)

• Día of roller = D
• Length of roller = L
• No of Helical Grooves = G
• Lead of Thread = L
• Cutter r.p.m = R
• Depth of Cut = C

8) Adjustment of cutter tilt angle (13) – Manually
9) Fixing of Cutter (10) as required – Manually
10) Start of operation from CNC Panel (46) – Manual.
11) The job continues till all the helix is complete – Automatic
Example:
• Roller Dia = 330 mm
• Roller Length = 36”
• No of Helical Grooves = 100
• Lead = 40”
• Cutter r.pm = 120 (adjustable based on hardness of the material)
• Depth of Cut = 1.5mm

12) The machine stops on complete of work – Automatic
13) Unloading of finished Roller (12) – Manually

Machine completes the operation as follows – AUTOMATIC by CNC

11. LIST OF FIGURES TO INCLUDE IN THE LATEST SPECIFICATION:

1. Assemble drawing
2. Fig. A is a front view of the machine.
3. Fig. B is a side view (L) of the machine.
4. Fig. C is a side view (R) of the machine.
5. Fig. D is a Top view of the machine.
6. Fig. E is a back view of the machine.

The detailed drawing of the Invention
HEADSTOCK PEDESTAL (70) 100% alloy / graded closed grained cast iron casting. BED (71) 100% alloy / graded closed grained cast iron casting and Heavy duty “V” guide bed with in-built dovetailed top for all mountings like bed, headstock gearbox and heavy loaded roller etc, ensuring higher structural strength against vibration and also against cantilevered deflections of head stock and Tailstock.
CARRIAGE (4) it can move on the bed forward and reverse motion with the help of “Z” axis. CROSS SLIDE OF ‘X’ AXIS (5) the tool movements on ‘X’ axis depend on this cross slide and the cross-slide travels with help of self-lubricating turcite sheet. CROSS SLIDE OF ‘Y’ AXIS (6) the tool movements on ‘Y’ axis depend on this cross slide and the cross-slide travels with help of self-lubricating turcite sheet. HEADSTOCK (2) it is fitted on the end of the machine bed, Each and every drive starts from headstock gear box.
TAILSTOCK (3) Rollers hold and rest on this tail stock safely since heavy duty bearing is fitted on same. The tail stock is also equipped with sliding system so that it can be able to hold various lengths of rollers easily. CHASING TOOL POST (7) It holds the tool Holder. BALL SCREW OF ‘Z’ AXIS (8) it helps to drive the carriage from start to end on the bed. It is made from C40 shaft duly hard and ground with 4 TPI thread complete with phosphorous bronze nut. CROSS SLIDE BALL SCREW OF ‘X’ AXIS (9)this ball screw is used for movement of cross slide along “X” axis. CROSS SLIDE BALL SCREW OF ‘Y’ AXIS (10) this ball screw is used for movement of cross slide along “Y” axis. HEADSTOCK CHUCK (58) this heavy-duty chuck used for holding the job firmly.
HEADSTOCK GEAR BOX (59) It is used for spindle drive servo Motor. ‘Z’ AXIS SERVO MOTOR (64) the saddle or carriage can move to and fro by this “Z” Axis Servo Motor which operates the ball screw. It moves forward and reverses according to the programming of the CNC controller. SERVO MOTOR FOR MAIN SPINDLE (57) this motor is used for “C” axis drive, which controls the spindle movement through the CNC controller. SERVO MOTOR FOR ‘X’ AXIS (65) & SERVO MOTOR FOR ‘Y’ AXIS (66) These are fitted with “X” & “Y” axis servo motors. LUBRICATING PRESSURE PUMP (11) Full machine is lubricated through this lubricating pressure pump, The smooth movement is ensured for carriage, cross slide, “Z” axis ball screw, “X” axis ball screw, Spindle etc. COOLING TANK (12) & HIGH PRESSURE PUMP WITH MOTOR (13)High Pressure Cooling Pump helps the cutting of the metal and maintains longer life of insert or tools. FEEDBACK ENCODER (60) the function of the encoder is to give the pulse to servo motor through the CNC controller for main spindle rotation CNC CONTROL PANEL (56) all type of operations are controlled by this control panel. It is totally operated by CNC controller. A special type of software is incorporate with this CNC controller. Contactors are also incorporated in the panel which helps for Milling and Chasing operations. FLEXIBLE DRAG CHAIN (55) All cable and water connection line protect and smoothly travels by this drag chain.
CNC Stalwart is used for three major operations for CTC roller sharpening and these are TURNING, CHASING, MILLING in addition to LATHE work.

12. THE OPERATING PROCEDURE / SEQUENCE OF OPERATION OF THE MACHINE IS DESCRIBED BELOW:

i. Common Operation:
a. Set the sharpening roller on tailstock and fit the top clamp properly by adjusting the tailstock with rack pinion assembly according to the length of the roller. Adjust the dog chuck jaws to get the roller in line with tailstock
and trueness of alignment of the roller can be checked through dial indicator. The whole machine bed is situated on 02 nos. Casting pedestal namely Pedestal for headstock and tail end gearbox pedestal. The Headstock Gearbox containing main worm and gear for milling and main spindle which holds the base plate holding Dog Chuck.

b. Checks all the electrical wirings are properly align in the drag chain so that in operation there should not be any unnecessary pulling of wire occur.

c. Remove the coupling for CNC operation and for manual milling operation fix the coupling.

d. Give the power supply to the CNC control panel and wait for display screen to boot up completely.

e. For Carriage movement over bed is achieved through Main Ball Screw (used for minimum backlash) driven by Z-axis drive unit and for Cross Slide movement over Carriage is achieved through Cross Slide Ball Screw (used for minimum backlash) driven by X-axis drive unit.

f. At the time of operation of cutting the roller automatic cooling mechanism is there for to cool the insert and cutter tip heated by cutting friction thus life of tool gets increased. This cooling arrangement is done through pipe; nozzle etc and water pump through Coolant pump and a coolant tank for circulating the coolant water works as reservoir.

g. For lubricating the contact points/surfaces for mechanical movement there is automatic lubrication system preset with proper pipelining and lubricating pump.

h. As per international safety norms all the moving parts are covered with safety guard and to collect the cutting chips there is chip tray provided.

ii. CNC Milling:
a. After the common procedure done, set the reference point (Home position) through operating the panel and then from headstock start the cut (but giving the cut in small depth) on roller and check it matches the pre-milling path for re-milling operation.

b. The milling cutter is mounted on arbor shaft which actually fitted on cutter mounting bracket and the same locked up with back bracket and have the tilting arrangement to adjust the angle so that shoulder and slop ratio on roller can be achieved as per needed.

c. There are four servo motor involved in the milling operation. The Z-axis servo , X-axis servo and Y-axis servo have optical encoder attached to the same for feedback the position signal. And the C Axis (Spindle Servo) is attached through spindle gear box and the encoder for the spindle positioning feedback is mounted on the extended shaft of the spindle.

d. At first the cutter goes to home position at the tailstock side through Z-axis servo movement (intern carriage movement) controlled by its associated encoder (feedback the position signal) to CNC unit and then the CNC controls the movement by giving the command to servo drive. After carriage return to home position X-axis servo starts and move the cross slide to engage the cutter for cutting the roller, through controlled signal given from the CNC unit and its associated encoder provides the feedback signal to CNC unit to judge the cross-slide position.

e. Spindle Servo starts to rotate the spindle.

f. Cutter motor starts and also coolant pump starts along with carriage movement towards headstock starts.

g. The Z-axis movement and spindle movement are interlinked in such a way that speed of them is synchronized, thus helix angle remain as desired.

h. After cutting finished carriage return to home position. After carriage positioned at home position spindle servo rotates in a calculated angle programmed at CNC unit for indexing the next helical cutting.

iii. CNC Chasing: -
a. After the common procedure done, set the reference point (Home position) through operating the panel and also set or modify the offset (as desired) of the work piece (roller) and tool by moving the cross slide and carriage through jog mode from CNC unit.
The cutting insert fitted in tool holder which fitted in Tool post on cross slide. In chasing operation fresh chasing or re-sharpening done in same way just in case of re-sharpening insert tip have to match with groves.

b. In chasing operation Spindle Servo moved in fixed speed but in operation Z and X-axis servo moves in different speed. At first insert comes at offset position of roller through z and x axis servo movement, spindle start rotating, and coolant pump starts then insert move (through cross slide X servo movement) towards roller surface for cutting. After cut completed as per TPI depth of cut set insert move (through cross slide X servo movement) away from roller surface.

c. Z Axis servo rotates and carriage move for 1 tooth as per TPI selected then again cross slide move towards roller surface for cutting. The operation repeats until roller full length cutting done.

d. After finish carriage came back to tailstock home position.

iv. CNC Lathe: -
a. This Machine is also capable of turning operation, bore operation etc.
b. In case of normal lathe operations just the tailstock needs to be replaced by other fixtures but the operation will be controlled through the same CNC panel.
c. In case of turning operation, the Spindle servo speed is fixed as well as Z-axis servo speed also fixed. After X-axis servo moves the cross slide towards roller surface to cut it stops. The same tool holder can be used, only different insert needs to use.

13. THE MAIN ADVANTAGES OF THE PRESENT INVENTION IS:

a. As the CNC Stalwart is a universal all in one machine to sharpen one CTC roller, have to mount the same for once and all the turning, chasing and milling job will be finished through one machine.

b. CNC controlling the operation thus accuracy is very high and time saving. As the chasing and milling done in one machine grooving and milling profile become perfect and accurate each time. That means TPI, Depth of cut, Helix angle, No. Of helix can be done to perfection and can be obtained as desired.

c. Any no. of Helical Grooves can be made by this machine. For example, instead of 80 helical grooves or 100 helical grooves we can make any number of helical grooves as per circumference by the help of CNC controller.

d. Power Consumption: - Connected Load for Stalwart is 15.76 kW whereas Active Load is 10.4 kW which is much lesser than the traditional machines for example in traditional Milling and chasing machine, the Active load is 12.29 kW.

e. Time Consumption: - It takes 6.5 Hrs. to process a 13” X 36” Roller in traditional machines whereas with this machine, it will take around 1.5 Hrs. to process a single one. Therefore, the time consumption for processing a single roller gets reduced by 75.4%

f. Power Saving – Due to fast process control in stalwart we can save power around 52.3 % per roller as compared to traditional machines.

g. As processing time is less for this machine the Life cycle will automatically increase nearly about three times.

h. Manpower Saving: - As the Chasing and Milling operation is done automatically in one machine that means we need less manpower to do the process and also will get perfection as desired.

i. Covered Frame Structure: - The covered frame structure of this machine allows for better safety and ensures clean operation without any environmental contaminations and smoother operation than the traditional ones.

j. Any no. of TPI (Threads per Inch) can be made with this machine. For example, instead of 8 TPI or 10 TPI we can do any no. of TPIs by the help of CNC Controller.

k. It offers Minimum Cutting Force, Minimum Heat Generation because of that the life of rollers, is increase as well as the life of Machine.

l. Machine is fitted with a Self-Centring four jaw chuck to ensure easy and accurate centring of job with respect to the ball screw/ Bed.

m. Movement of saddle on bed is automatically controlled with the help of servo motor and a ball screw.

n. A cross slide (Axis X) is fitted on the aforesaid saddle with servo motor and ball screw for the movement of the back cutter assembly. Another cross slide (Axis Y) is mounted on cross slide Axis X which is operated by servo motor. Cross slide Axis Y enables movement of front cutter assembly through ball screw operated by servo motor.

o. There is Tool Post / Insert Holder for Grooving and Re-sharpening operations which is fitted with the Y-axis.

p. Arbour shaft complete with cutter arrangement / cutting tool have three axis movement / rotation.

q. Arbour Shaft holding bracket along with arbour shaft can be moved vertically / along the axis of the arbour shaft. A dove tail arrangement provided with the intermediate arbour bracket allows arbour shaft and bracket to move vertically on intermediate arbour bracket.

r. Vertical adjustment of cutter / cutting point on job can be measured / Adjusted based on dial indicator fitted on height adjusting lever assembly mounted on arbour guide bracket. It ensures accurate / Required position of the cutter based on centre line of job.

s. Arbour Shaft complete with Arbour shaft bracket and intermediate Arbour bracket can be rotated on Arbour guide bracket to achieve rotation of cutter assembly on vertical axis.

t. Rotation of cutter, Arbour shaft & bracket, intermediate Arbour bracket is achieved with the help of an open gear arrangement along with a worm reducer to ensure finer adjustment of cutter position on job.

u. The machine has two cutter heads complete with Arbour shaft assembly so that two separate helical grooves can be machined simultaneously.

v. Automatic Adjustment of cutter heads through Encoders to achieve accurate location of each helical grooves/ Depth of cutters. It ensures uniform depth of cut on job for any dimension of milling cutter fitted on Arbour shaft.

w. The tail end support on the bed consists of a tail stock mounted with four-roller supporting arrangement. The four-roller support bottom arm is clamped on roller support top arms with the help of two separate hydraulic cylinders.

x. Both the top arms with roller support bearings gets disengaged and rotates on a fulcrum point with the help of two separate hydraulic cylinders.

y. A tail stock clamping unit complete with hydraulic cylinder ensures engagement of tail stock assembly on bed.

z. A Tail Stock complete with four-roller arrangement supporting block can move automatically to a desired length for different size of rollers. Movement of the supporting block is controlled by an arrangement of induction geared motor along with a lead screw and nut.

aa. The aforesaid lead screw nut holding the supporting block is controlled by a set of limit switches which ensures desired locations of the tailstock on the bed.

bb. The tail stock completes with four-roller arrangement supporting block can be shifted to any location based on the size of the job/ CTC rollers.

cc. During changing the location of tail stock assembly to any desired location based on the size of the job, the top roller supports get open and the clamping arrangement gets disengaged automatically through hydraulic cylinders.

dd. The disengagement of rollers support takes place only when the machine is not fitted with the job. This ensures safety measurement during the system.

ee. After disengagement of the roller supporting arrangement from the bed the tailstock assembly moves to its desired location controlled by limit switches mentioned by point no. 26.

ff. Once the movement of tail stock is completed, hydraulically operated clamping arrangement gets engaged automatically.

, C , Claims: 1. An automatic CNC dual cutter machine for milling multi grooves at a time on CTC rollers as well as cutting circumferential grooves on CTC rollers. The machine comprises of:
a headstock (2) and a tailstock (3) provided for placing the CTC roller (1) in between the said parts;
wherein said automatic CNC dual cutter machine further includes a carriage (4), cross slide of ‘X’ axis (5), cross slide of ‘Y’ axis (6), chasing tool post (7), ball screw of ‘Z’ axis (8), cross slide ball screw of ‘X’ axis (9), cross slide ball screw of ‘Y’ axis (10), lubricating pressure pump (11), cooling tank(12) & high pressure pump with motor (13), Flexible Drag Chain (55) and CNC control panel (56).
wherein the said CTC roller (1) is fitted at the headstock chuck (58) which is controlled by headstock servo base plate (14) with servo motor for main spindle (57), rotates the said CTC roller (1).
wherein said cross slide of ‘X’ axis (5) and cross slide of ‘Y’ axis (6) move towards the CTC roller (1) as per the reference points simultaneously for cutting multi grooves at a time on said CTC roller (1).
wherein said cross slide of ‘X’ axis (5) move towards the CTC roller (1) as per the reference points for cutting circumferential grooves on said CTC roller (1) by chasing tool post (7) on ‘Y axis.

2. The automatic CNC dual cutter machine of claim 1, wherein said headstock (2) further includes a headstock chuck (58), headstock gear box (59), headstock servo base plate (14) with servo motor for main spindle (57) and feedback encoder (60).

3. The automatic CNC dual cutter machine of claim 2, wherein said the headstock servo base plate (14) with servo motor for main spindle (57) runs the headstock gear box (59) which rotates the headstock chuck (58) which helps to rotate the CTC roller (1). The feedback encoder (60) provides the position value.

4. The automatic CNC dual cutter machine of claim 1, wherein said tailstock (3) further includes a four-roller assembly (15), hydraulic brake assembly (16), hydraulic cylinder assembly (17), lead screw (18), gear coupled motor (19), holding plate (20), cam shaft (21), cam plate (22), pressure arm LH (23), pressure arm RH (24), limit switch (61) and safety sensor (62).

5. The automatic CNC dual cutter machine of claim 4, wherein said the gear coupled motor (19) of the tailstock (3) operates the forward and backward movement of the tailstock (3).

6. The automatic CNC dual cutter machine of claim 4, wherein said hydraulic brake assembly (16) with gear coupled motor (19) holds and releases the holding plate (20) of the tailstock (3).

7. The automatic CNC dual cutter machine of claim 4, wherein said hydraulic cylinder assembly (17), cam shaft (21) and cam plate (22)17 help in opening and closing of the pressure arm LH (23) and pressure arm RH (24). The limit switch (61) is used for position control.

8. The automatic CNC dual cutter machine of claim 4, wherein said safety sensor (62) when enabled the hydraulic cylinder assembly (17) will not work and safety sensor (62) when disabled the hydraulic cylinder assembly (17) will work.

9. The automatic CNC dual cutter machine of claim 1, wherein said tailstock (3) further includes, a manual operating wheel (25) to manually operate the tail stock with help of lead screw (18).

10. The automatic CNC dual cutter machine of claim 1, wherein the said carriage (4) is coupled with ball screw of ‘Z’ axis (8) by holding bracket assembly for ball screw nut (63) which is controlled by the ‘Z’ axis servo motor (64).

11. The automatic CNC dual cutter machine of claim 1, wherein the said cross slide of ‘X’ axis (5) includes cross slide ball screw of ‘X’ axis (9), servo motor for ‘X’ axis (65), drive pinion of ‘X’ axis (26), driven pinion of ‘X’ axis (27), manually operated adjusting wheel for the movement of the ‘X’ axis (28).

12. The automatic CNC dual cutter machine of claim 11, wherein the said drive pinion of ‘X’ axis (26) and driven pinion of ‘X’ axis (27) is used for manually operated adjusting wheel for the movement of ‘X’ axis (28).

13. The automatic CNC dual cutter machine of claim 1, wherein the said cross slide of ‘Y’ axis (6) includes cross slide ball screw of ‘Y’ axis (10), servo motor for ‘Y’ axis (66), manually operated adjusting wheel for the movement of the ‘Y’ axis (67) and the cross slide of ‘Y’ axis (6) is fitted over the cross slide of ‘X’ axis (5).

14. The automatic CNC dual cutter machine of claim 1, wherein the said cross slide of ‘X’ axis (5) holds the arbour shaft of ‘X’ axis (29), arbour shaft bracket of ‘X’ axis (30), gear box for fixed cutter head (68), motor for arbour shaft of ‘X’ axis (69), swiveling pin of ‘X’ axis (31) and milling cutter for ‘X’ axis (32).

15. The automatic CNC dual cutter machine of claim 14, wherein the said 5arbour shaft bracket of ‘X’ axis (30) helps to absorb the thrust load / cutting load during operation of the CTC roller (1).

16. The automatic CNC dual cutter machine of claim 1, wherein the chasing tool post (7) further includes 35 bottom base for insert holder tool post (33) and top plate for insert holder tool post (34) fitted in cross slide of ‘Y’ axis (6).

17. The automatic CNC dual cutter machine of claim 17, wherein the said top plate for insert holder tool post (34) further includes revolving tool holder (35).

18. The automatic CNC dual cutter machine of claim 13, wherein said servo motor for ‘Y’ axis (66) controls the to and fro movement of the cross slide of ‘Y’ axis (6).

19. The automatic CNC dual cutter machine of claim 1, wherein said cross slide of ‘Y’ axis (6) further includes arbour guide bracket of ‘Y’ axis (36) and arbour shaft bracket of ‘Y’ axis (37).

20. The automatic CNC dual cutter machine of claim 1, wherein said cross slide of ‘Y’ axis (6) further includes spring holding bucket for tilting cutter head (38), holding shaft for tilting cutter head (39), gear box for tilting cutter head (40), bracket assembly for gear box on tilting cutter head (41), hand wheel assembly for gear box on tilting cutter head (42) for the tilting movement of the arbour guide bracket of ‘Y’ axis (36).

21. The automatic CNC dual cutter machine of claim 19, wherein the said 6 arbour shaft bracket of ‘Y’ axis (37) helps to absorb the thrust load / cutting load during operation of the CTC roller (1).

22. The automatic CNC dual cutter machine of claim 1, wherein said cross slide of ‘Y’ axis (6) further includes intermediate dovetail arbour plate (43).

23. The automatic CNC dual cutter machine of claim 1, wherein said cross slide of ‘Y’ axis (6) further includes vertical tilting for arbour bracket holding plate (44).

24. The automatic CNC dual cutter machine of claim 1, wherein said cross slide of ‘Y’ axis (6) further includes arbour shaft of ‘Y’ axis (45), swiveling pin of ‘Y’ axis (46), adjusting screw on cutter head assembly (47) and flywheel (48) for radial movement of cutter head assembly (49).

25. The automatic CNC dual cutter machine of claim 24, wherein the said cutter head assembly (49) further includes a lever (50), flynut (51) and adjusting wheel (52).

26. The automatic CNC dual cutter machine of claim 1, wherein said cross slide of ‘Y’ axis (6) further includes bracket assembly for cutter adjustment (53) and dial indicator (54), for the vertical movement of cutter head assembly (49).