FORM 2
THE PATENTS ACT 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)

TITLE OF THE INVENTION
CNC VERTICAL TURNING MACHINE (MODEL - PTC 2300)
APPLICANTS
PREMIER LIMITED
AN INDIAN COMPANY
of 58, NARiMAN BHAWAN,
NARIMAN POINT,
MUMBAI-400 021, INDIA
The following specification particularly describes the invention and the manner in
which it is to be performed
CNC VERTICAL TURNING MACHINE ( MODEL - PTC 2300 ) FIELD OF INVENTION:
The present invention relates generally to CNC Vertical turning machine, and more specifically to a new and unique vertical turning machine which is used for machining parts up to 2000 mm diameter but of maximum component size 2300 mm diameter. Normally in the range 1600 to 2500 mm diameter, parts are very less for machining so majority machine tool builders avoided to build up this type of machine for these components.
BACKGROUND OF THE INVENTION :
Turning machines are well known in the art. A typical turning machine includes a rigid base, a chuck assembly for holding a piece of stock material in place relative to the machine, a motor and transmission for rotating the chuck assembly and stock material at a desired speed, and a tooling assembly for machining the stock material as it is turned. The tooling assembly generally includes a ram which holds the cutting tools and allows for any of a number of these cutting tools to be interchanged for use in machining a part. Typically, now a days turning machines also include a computerized numerical controller which controls the table rotation by servo spindle motor and radial and axial positioning of a cutting tool by axes servo motors to produce a part of the desired shape.
Turning machines are generally adapted to produce a wide variety of parts, and thus are capable of operating at a wide variety of speeds and of holding a large number of different cutting tools which can be interchanged during the machining process to produce the particular part desired. While conventional turning machines are well adapted to perform a wide variety of machining operations, there are unfortunately several drawbacks with existing turning machines. For example, conventional turning machines require a cooling lubricant to be applied to the cutting edge of the cutting tool to remove heat generated during the cutting operation. Otherwise, the heat generated from the cutting operation may cause the turned part, such as an aluminum part, to melt, and may otherwise damage the finish of the machined part. Unfortunately, coolant is expensive, leaves a residue on the finished part and on the turning machine, and may pose environmental and health problems.
Another drawback of many turning machines is that the rotational speed of the stock material, and thus the speed at which the materia! can be machined, is limited to speeds below which these machines tend to experience chatter and vibration which can harm not only the machine but also damage the part being machined. As the diameter of part increases then while rotating the component & because of centrifugal forces develop , there are chances of component may come out of chuck and make accident which is hazardous ., So RPM has to be restricted or force muster roecharusvv, should fee Incorporated
Furthermore, in recent years there has emerged a need to machine work piece of large size on a production basis with usual requirements of a high accuracy of finish and a maximum speed of production. Such requirement exists, for example, in the field of production valves, casings, cylinder blocks, pistons, piston rings and bearings for internal combustion engines of rails. Hence, there is a need for a machine tool which is capable of machining work pieces rapidly and accurately to have required non-uniform and large shaped profiles. It is also required that such a machine must have the capability of altering the tool position a number of times within a revolution, if it is to machine oval and elliptical profiles and must be able to do this at high speeds.
Accordingly, there was a long felt need to provide a vertical turning machine for machining components of 400-2000 mm diameters, which in general, substantially nullifies/reduces the aforesaid drawbacks and is adapted to take care of the requirements in the preceding paragraph.
The present invention meets the aforesaid long felt need.
All through out the specification including the claims, the words "frame", "chuck", "assembly", "motor", "transmission", "tooling", "turret", "drive assembly", "work piece", "driven pulley", "spindle assembly", "turning machine", and "cutting assembly" are to be interpreted in the broadest sense of the respective terms and includes all similar items in the field known by other terms, as may be clear to persons skilled in the art. Restriction/Limitation if any, referred to in the specification, is solely by way of example and understanding the present invention. OBJECTS OF THE INVENTION
It is the principal object of the present invention to provide a vertical turning machine for 2300 mm diameter machining components (turning upto 2000 mm diameter only ) but which in general, substantially nullifies/reduces the drawbacks encountered in prior art and takes care of the requirements as mentioned in the portion under the heading "Background of the invention.
It is yet another object of the present invention to provide a vertical turning machine which is adapted to turn the work piece to be machined at high rate with minimal vibration and chatter.
It is a further object of the present invention to provide a vertical turning machine which has a minimal number of moving parts.
It is yet another object of the present invention to provide a vertical turning machine which is adapted to high accuracy finish and ensures maximum speed of production.
It is a further object of the present invention to provide a vertical turning machine which is adapted to machine work pieces of 2300 mm diameters rapidly and accurately to have required non-uniform and large shaped profiles.
It is yet another object of the present invention to provide a vertical turning machine which has the capability of altering the tool position a number of times within a revolution.
It is yet another object of the present invention to provide a vertical turning machine which requires substantially low maintenance consequently, rendering the manufacturing cost to be substantially low.
How the foregoing objects are achieved and the other aspects of the present invention will be clear from the following description, which is purely by way of understanding and not by way of any sort of limitation. SUMMARY OF THE INVENTION
Accordingly, the present invention provides a vertical turning machine comprising at least a base, a spindle assembly for turning a work piece, a motor and transmission means for transferring power from motor to spindle assembly and a tooling assembly for machining the work piece as it is turned, said machine further having a rotary table for rotating said work piece, single column, a moving cross rail on the guide ways of column, at least one
cross slide movable in a horizontal direction along guide ways of the cross rail; at least one ram suspended from ram housing and movable vertically along guide ways of said ram housing
In accordance with preferred embodiments of the turning machine according to the present invention:
Machine's column is of cast structure with an integral guide ways and are fixed to said table base through joining pieces which are also made up of cast iron.
-a special structural element is mounted in between each joining piece and respective column; -there is provided an automatic tool changer for said ram consisting of horizontal disc type magazine with tool pockets for boring, turning, milling and drilling ;
-said magazine is mounted on separate fabricated column located on the right side of said magazine;
-bearing of said table comprises a preloaded anti-friction bearing system for high axial and radial rigidity and accuracy involving a combination of a thrust bearing to take the axial force and a precision angular contact bearing to take the radial forces;
Said machine's table ( 1800 or 2000 mm ) is of SG iron material and is mounted on said bearing system having jaw boxes clamped in the T-slots in said table, additional locking being provided so that jaw boxes do not fly off in the event of failure of clamping , additional T-slots being provided on said table and the hardened jaws having individual adjustment and adapted to be reversed for OD / ID clamping;
-the spindle is adapted to be turned at a rate of at least approximately 1.6-35 (RPM) revolutions per minute so that chip fragments aviate off said work piece thereby removing heat from said work piece.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The nature and scope of the present invention will be better understood from the accompanying drawings, which are by way of illustration of some preferred embodiments and not by way of any sort of limitation. In the accompanying drawings,
Fig 1(a) and 1 (b) illustrate the cross rail assembly and X-axis drive assembly of the vertical turning machine according to the present invention;
Fig 2 schematically illustrates the ram balancing assembly of the vertical turning machine according to the present invention;
Fig 3 schematically illustrates the Z-axis kinematics of the vertical turning machine according to the present invention;
DETAILED DESCRIPTION OF THE INVENTION
The following describes some preferred embodiments of the present invention, which are purely for the sake of understanding the present invention and not by way of any sort of limitation.
Various types of machining are already known such as below:
. Boring
. Turning
. Facing
. Taper Turning
. Tapping
Various types of machining can be performed using adequate type of tool and moving the tool properly as shown below by way of example.
• Boring Machining of internal Surface.
• Turning Machining of External Surface.
• Facing Machining of Top Surface.
• Taper Turning Machining of Taper Surface.
Also, Vertical turning machine with live spindle ('C' axis) gives following operations: Milling. Slotting and Tapping operations.
• Tapping Tapping is used to Thread holes inside a surface

The present invention relates generally to CNC Vertical turning machine and more specifically to a new and unique vertical turning machine which is adapted for machining of work piece of diameter up to 2000 mm.
Machine's specifications are as follows

Turning height reduced by mm
Number of T-slots 4 FULL 8 HALF 4 FULL 8 HALF
Size of T-siots mm 28 H12 28 H12
Independent stroke of individual jaw mm 115 40
Simultaneous srtoke of jaws mm N.A. 13.4
1.7 Automatic tool changer
Automatic tool changer foe ram consisting of a
horizontal disc type magazine with coded tool
pockets and power clamping in ram for turning
tools . Clamping of tool holders in symmetrical dovetail location, positive locking in cutting force direction. The
magazine is mounted on a separate column
located on the right side of the machine. Tools
are locked in magazine pockets by means of spring loaded grub screws.
Tool capacity in magazine 20 12
Maximum overhung of turning tool from
ram
centre mm 200 200
Maximum length of tool holder ( Boring bar) mm 500 500
1.8 Electricals / Motors
Operating Voltage V 415 ± 6% 415+ 15% 415-18% WITH
STABILISER
Frequency Hz 50 ± 3 %
Phase 3 PHASE
Total connected load kVA 175 200 kVA with Live Spindle Option
Main motors details
Spindle motor kw/rpm 60/75,/ 3500
X axis motor Nm/rpm 38,/ 2000
Z axis motor Nm/rpm 38,/2000 with brake
Weight of basic machine { approx) kg 35000

The vertical turret lathe includes: A rotary table for rotating a work piece; single column; a simply supported moving cross rail supported by the columns; ram housing movable in a horizontal direction along the guide ways of the cross rail; ram suspended from the ram housing and movable vertically along the guide ways of the ram housing; one automatic tool changer unit. There may be more than one ram and more than one saddle.
The present invention provides a dedicated vertical turning machine which can machine the large sized components with greater efficiency. Additionally it can machine the part at either side of the table center and able to produce a large range of parts at very high speed and preferably the use of cooling lubricants.
The invention includes:
1. Bali Screw - both the axes ( X and Z ) have hardened and ground precision ball screw with preloaded double nuts. This ensures high running accuracy. Both the axes are driven by AC servomotors through a gear pair. Additionally, the servomotor for the z axis has a built in holding brake to prevent the axis from moving down in power failure condition.
2. The Base is of sufficient mass and area to provide dampening which facilitates to reduce vibrations and harmonics generated by the machine, during machining operation. The Table Base is a thermo symmetric cast structure providing a stiff and rigid machine base. The table drive gear box is integral to it. The table base also acts as a sump for the table bearing / gear box lubrication system.
3. The Column is cast structure with integral ground guide ways. They are fixed to the base. The column is of thermo symmetric design. It carries the cross rail with cross rail head (ram head). The cross rail elevating drive/gear boxes are fixed on the column top.
4. Main Drive : The table is driven by AC spindle motor through a hydraulically shifting 2 stage gear box and a main pinion I gear rim pair. For infinitely variable table speed within the maximum and minimum values (in 2 ranges). The gear box has high efficiency due to vertical and symmetrical arrangement of the motor, gear box in the base-a maximum of 3 pairs of gears in mesh at any time. Also there is no change in direction in the kinematic as the spindle motor is mounted vertically at the rear of the table base. The spindle motor is connected to drive the gear box by a flat belt. The main drive gear box (gears and bearings) and the table bearing system are lubricated by a separate recirculating lubrication system which supplies the lubricating points with oil from the oil chamber in the table base, this lubrication system is going on as long as the machine is working.
5. Automatic tool changer for ram consisting of a horizontal disc type magazine with coded tool pockets and power clamping in ram for turning tools clamping of tool holders in symmetrical dovetail location, positive locking in cutting force direction. The magazine is mounted on a separate column located on the right side of the machine. Tools are locked in magazine pockets by means of spring loaded grub screws.
In accordance with one aspect of the present invention, the machine is dedicated to the manufacture of a limited range of parts includes a base, a spindle assembly for holding and turning the work piece, a motor, a direct drive assembly for transferring power from the motor to the chuck and cutting assembly, the base being of sufficient mass and area to provide a dampening force that facilitates to reduce vibrations and harmonics generated by the machine, the motor and direct drive assembly being adapted to rotate the chuck assembly about a vertical axis at a rate wherein chip fragments aviate off of a workpiece being machined such that heat generated by the tooling process is removed by the chips which have absorbed the heat.
In accordance with another aspect of the machine, a vertical turning machine includes a base, a spindle assembly mounted to the base for turning a workpiece, a motor mounted to the base for powering the spindle assembly, a direct drive assembly for transferring the power from drive motor to the spindle and a cutting assembly for removing material from the workpiece. The direct drive assembly includes a first timing pulley mounted to the encoder and a second mounted to the spindle assembly and a flat belt extending between the pulleys.
The invention will be more apparent from the description of its exemplary embodiment taken with reference to the accompanying drawings.
The vertical turning machine is designed and adapted as a machine dedicated to the manufacture of comparatively large sized parts with the usual requirements of a high accuracy of finish and a maximum speed of production. As such, the vertical turning machine is preferably designed with a minimal number of moving parts and assemblies and is adapted to turn the work piece to be machined at a high rate with minimal vibration and chatter The vertical turning machine includes a base to which a AC spindle motor, a spindle assembly is mounted. The base and columns are preferably connected and designed with adequate mass and structural rigidity to provide significant dampening to the machine to reduce harmonics and vibrations (i.e. chatter) generated by cutting action of the machine and rotation of the drive motor.
CNC Vertical turning machines, and more specifically a new and unique vertical turning machine gives following operations.
Turning, boring, facing & machine with Live spindle {'C' axis) gives Drilling, tapping, milling & slotting operations.
AS illustrated in the accompanying figure 1(a), the cross rail assembly includes the cross rail(1), ball screw(2), the motor{3) and linear encoder(4).
The accompanying figure 1(b) illustrates the X-axis drive assembly which includes X-axis motor(3'), pinion(5), X-axis ball screw(2') and gear{6). . Preferably, an AC servomotor is coupled through gear transmission to precision ball screw. It is the gear drive to ball screw which results in higher rapid travel for X axis. The present invention preferably provides at least two columns, casted by FG-300. Each column is mounted at the side of the table base with the help of joining piece. A special structure material is inserted in between the joining piece and the column. This helps in establishing a good contact between the columns and joining pieces as well increases the dampening effect. Columns support the cross rail. The cross rail carries the cross rail slide.
The accompanying figure 2 illustrates a ram balancing assembly. It shows the Z-axis motor(3"), the ram(7), the ram balancing cylinder(8), the hydrostatic motor(9), the ram housing(10) and the tool holder(11). The tool holder(11) is located and clamped in the ram(7). Cutting tool clamping is through two hydraulic cylinders in a dovetail location. Ram(7) is fixed on cross rail slide and coolant is delivered at cutting point through adjustable coolant nozzles in tool holder.
Automatic tool changer (ATC) for ram consists of horizontal disc type magazine with tool pockets for boring, turning, milling & drilling tools. Special adapters are provided for mounting rotary tools. Magazine is mounted on separate column located on the right side of the machine.
The accompanying figure 3 illustrates the Z-axis drive assembly which includes Z-axis motor(3"), pinion(5), Z-axis ball screw(2") and gear(6'). Preferably an AC servomotor is coupled through gear transmission to precision ball screw. It is the gear drive to ball screw which results higher rapid travel for Z axis.
As illustrated in the accompanying figures 1(b), 2 and 3 the both X and Z axis, have high precision ball screw which provide good repeatability and fast traverse. These are lubricated by Central lubrication system by oil. Ball screw design is of both side supported type. Ball screws are driven by gear drive and servo motor.
The Table is manufactured from S.G. Iron. All the sliding surface of the table are hardened and ground for accurate turning and long sen/ice. Jaws are made by alloy steel, ensures better gripping force output even at cutting toad- Their stable gripping powers even at higher speed making them ideal for CNC application.
The table base assembly comprises the fixture, mounted on the top of the table. The main Spindle is driven by spindle motor of 60 Kw power capacity through Flat belt The table is stopped dynamically to bring it to a standstill at an oriented position.
Cross rail slide move in horizontal transverse direction on Cross rail guide ways through ball screw (X axis) and is driven by servo motor through gear transmission. For holding the vertical feed axis at a standstill without backlash during operating, a holding torque is generated by the servo motor.
Hydraulic power pack is used to clamp tool holder, for actuating the ram balancing cylinder, for actuating the chip guard and ATC door.
Automatic lubrication system is used; which provides lubrication in pressurized state to all sliding elements like ball screws, Ball screw support bearing etc. Recirculation type oil lubrication is provided for spindle assembly. Accumulator is given for safety to avoid accident in case of power failure.
Chip conveyor is designed to maximum chip carrying capacity 300 kg/hour
Slat type chip conveyor is used for carrying the chips from machine interior to chip trolley.
Both the chip conveyor & trolley are placed on ground in front of table base. Slat type Chip conveyor is very suitable to carry curly chips. Coolant tank is of 500 liter capacity along with rotary drum type filtration unit
Preferably, FANUC controller is used. Control panel is mounted on left side of machine. Swiveling type pendent box is mounted in front of the machine at side of operator which is designed on the basis of Ergonomics.
The rotary movement to work piece is achieved by spindle motor, flat belt and pulley mechanism.
The present invention represent an advance over machines of the prior art by providing a mechanically stiffer machine exhibiting improved dynamic characteristics. The inventive machine can be made more reliable than the machine of the prior art.
In a nutshell, the present invention comprises a vertical turning machine comprising at least a base, a spindle assembly for turning a work piece, a motor and transmission means for transferring power from motor to spindle assembly and a tooling assembly for machining the work piece as it is turned. The machine also has a rotary table for rotating the work piece, two columns, a simply supported cross rail supported by the columns. The machine also has at least one saddle movable in a horizontal direction along guide ways of the cross rail and at least one ram suspended from said saddle and movable vertically along guide ways of said saddle.
Preferably the columns are cast structure with integral guide ways and are fixed to said base through joining pieces. A special structural element is mounted in between each joining piece and respective column. It also consists of an automatic tool changer for the ram, consisting of horizontal disc type magazine with tool pockets for boring, turning, milling and drilling . The magazine is mounted on separate columns, located on the right side of the magazine.
The bearing of the table comprises a preloaded anti-friction bearing system for high axial and radial rigidity and accuracy involving a combination of a thrust bearing to take the axial force and a precision angular contact ball bearing to take the radial forces.
The vertical turning machine table is preferably of SG iron and is mounted on the bearing system having jaw boxes clamped in the T-slots in said table, additional locking being provided so that jaw boxes do not fly off in the event of failure of clamping . Additional T-slots are provided on the table. The hardened jaws have individual adjustment and can be reversed for OD / ID clamping.
The spindle is adapted to be turned at a rate of at least approximately 1.6-35 (RPM) revolutions per minute, so that chip fragments aviate off said work piece thereby removing heat from said work piece.
The vertical turning machine may have two or more said saddles and two or more said rams.
The present invention has been described with referance to some drawings and preferred embodiments, purely for the sake of understanding and not by way of any limitation and the present invention includes all legitimate developments within the slope of what has been described herein before and claimed in the appended claims.

WE CLAIM:
1. A vertical turning machine with above machine's specifications comprising at least a base, a spindle assembly for turning a work piece, a motor and transmission means for transferring power from motor to spindle assembly and a tooling assembly for machining the work piece as it is turned, said machine further having a rotary table for rotating said work piece, two columns, a simply supported cross rail supported by the columns, at least one saddle movable in a horizontal direction along guide ways of the cross rail; at least one ram suspended from said saddle and movable vertically along guide ways of said saddle.
2. The vertical turning machine as claimed in claim 1 wherein said columns are cast structure with integral guide ways and are fixed to said base through joining pieces.
3. The vertical turning machine as claimed 1 wherein there is provided an automatic too! changer for said ram consisting of horizontal disc type magazine with tool pockets for boring, turning, milling and drilling .

4. The vertical turning machine as claimed in claim 4 wherein said magazine is mounted on separate column located on the right side of said magazine.
5. The vertical turning machine as claimed in claim 1 wherein bearing of said table comprises a preloaded anti-friction bearing system for high axial and radial rigidity and accuracy involving a combination of a thrust bearing to take the axial force and a precision angular contact ball bearing to take the radial forces.
6. The vertical turning machine as claimed in claims 1 to 6 wherein said machine is of SG iron and is mounted on said bearing system having jaw boxes clamped in the T- slots in said table, additional locking being provided so that jaw boxes do not fly off in the event of failure of clamping , additional T-slots being provided on said table and the hardened jaws having individual adjustment and adapted to be reversed for OD / ID clamping.
7. The vertical turning machine as claimed in claim 1 wherein the spindle is adapted to be turned at a rate of at least approximately 1.6-35 (RPM) revolutions per minute so that chip fragments aviate off said work piece thereby removing heat from said work piece.
8. The vertical turning machine as claimed in claim 1 wherein there are provided two said saddles and two said rams.
9. A vertical turning machine substantially as herein described, particularly with reference to and as illustrated in the accompanying drawings.