FORM 2
THE PATENT ACT 1970 (39 of 1970)
&
The Patents Rules, 2 003 COMPLETE SPECIFICATION
(See Section 10, and rule 13)
1. TITLE OF INVENTION
TRAVELLING COLUMN CNC MILLING AND BORING MACHINE
2. APPLICANT(S)
a) Name : PREMIER LIMITED
b) Nationality : INDIAN Company
c) Address : 58, NARIMAN BHAVAN,
NARIMAN POINT, MUMBAI-400 021, MAHARASHTRA, INDIA
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed : -

FIELD OF INVENTION
The present invention relates generally to a milling and boring machine and more particularly to a Travelling Column CNC (computer numeric control) Milling and Boring Machine, and which is adapted with the built in boring spindle and milling spindle for multi operation without set up change with high spindle speed, stability, position accuracy. The machine possess balanced spindle with the set of precision bearings and which requires coolant lubricants to prevent the heat generated during machining process during machining process.
BACKGROUND OF THE INVENTION
Milling and boring machines are much known in the art. They are required for producing various type of work pieces of desired finish for different requirements. The challenges faced in the field milling and boring technology primarily comprise of producing high quality work pieces which are error free and possess precise surface finish. Producing larger number of such precise work pieces is an additional challenge looking at the manual tooling time and installation and uninstallation procedures. Further such manual setting of work pieces and tool not only increased production time but also increased the chances of human error in manufacture. Thus there is along felt need in the art to find a completely automated milling and boring machine which will produce finished work piece after a single installation possessing no interim manual work over and/or change in installation of work piece or tooling thus in turn lowering the overall production time.
The error free and high precision machine tool products are required to meet the continuous demand of Engineering, Automobile and Government Sector Industries like Power Sectors, Railways, Defense etc. In recent years there has emerged a need to machine number of work pieces with the high productivity and accuracies. Complex machining operations such as Milling, Facing, Boring, Drilling, Tapping, Deep Boring etc. are needed to be performed in single set up. Such are required in

the field of valves, casings, cylinder blocks, gear box housing, aerospace components and bearings blocks for internal combustion engines of rails.
Thus there is a long felt need for a machine tool which is capable of machining the work pieces rapidly and accurately to have required non-uniform and large shaped profiles. There is also a need that such a machine must have the capability of altering the tool position a number of times within machining cycle, with the machine having oval and elliptical profiles and able to do this at high speeds.
The present invention meets the aforementioned needs.
All through out the specification including the claims, the words "work piece", "tool", "machine head", "machine guard", "cross slide", "machine base", "pulley", "timer belt", "milling", "boring", "turning", "ball screws", "guide ways", "motors", and "control panel" 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
The principal object of the present invention is to provide an improved milling and boring machine capable of machining the work pieces rapidly and accurately to have required non-uniform and large shaped profiles.
It is another object of the present invention to provide an improved milling and boring machine capable of altering the tool position a number of times within machining cycle at high speeds, with the machine having oval and elliptical profiles.

It is yet another object of the present invention is to provide an improved milling and boring machine which produces precise and accurate work pieces without the need for any manual installation or change of tooling and/ or work piece.
It is a further object of the present invention to provide an improved milling and boring machine which reduces substantial finishing and/or manufacturing time of a work piece by cutting down on manual intervention for change in installation and/or alignment of work piece or tooling.
It is yet another object of the present invention to provide an improved milling and boring machine reducing error in the manufactured work piece by overcoming the need for repeated manual alignment requirement of tool or work piece.
It is another object of the present invention to provide an improved milling and boring machine which possess electronic means for overall process control and precision.
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
The present invention discloses a Travelling Column CNC milling and boring machine comprising, at least one machine bed , a saddle, a rotary table assembly, and a column mounted on said machine bed, a head stock assembly housed inside said column, and a control panel equipped with an electronic calculating means for monitoring the entire milling process.

According to preferred embodiments of the Travelling Column CNC of the present invention:
- said head stock assembly comprises a spindle motor housed in a spindle housing, a quill motor housed in a rear housing, a nose block housing a milling and boring spindle assembly, and a plurality of pulleys and timer belt;
- said rotary table assembly comprises a main base, a table motor, a hydrostatic Lucas unit, a bottom table and a rotary table driven by said motor;
- said saddle comprises, rack and pinion drive for X-axis and a gear box for higher reduction and the maximum torque;
- said column is a thermo-symmetric cast member which can be mounted on column base;
- said milling and boring machine comprises a travelling column CNC milling and boring machine;
- said spindle is turned at a rate of at least 15-1500 revolutions per minute.
- said NC Rotary Table is hydrostatically operated;
- said machine comprises a separate Coolant tank, Chip trolley and Slat type chip conveyor for the removal of chips; and
- said machine comprises a machine guard designed in terms of the ergonomic considerations and operators safety.
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) illustrates the perspective layout of the improved Milling and
Boring Machine as according to the present invention;

Fig 1(b) illustrates the Side view of the improved Milling and Boring
Machine according to the present invention;
Fig 1(c) illustrates the top view of the improved Milling and Boring
Machine according to the present invention;
Fig 2 illustrates the Head Stock of the improved Milling and Boring
Machine according to the present invention;
Fig 3 schematically illustrates the N C Rotary Table of the improved
Milling and Boring Machine according to the present invention;
Fig 4a and 4b schematically illustrates the Milling and Boring Spindle Assembly of the improved Milling and Boring Machine according to the present invention;
Fig 5(a) schematically illustrates the X-axis kinematic drawing of the
improved Milling and Boring Machine according to the present invention;
Fig 5(b) schematically illustrates the Y-axis kinematic drawing of the
improved Milling and Boring Machine according to the present invention.
Fig 5(c) schematically illustrates the Z-AXIS Kinematic drawing of the
improved Milling and Boring Machine according to the present invention.
Fig 5(d) schematically illustrates the W-Axis Kinematic drawing of the
improved Milling and Boring Machine according to the present invention.

Fig 6 schematically illustrates the N C Rotary Table Kinematic drawing
of the Milling and Boring Machine according to the present invention.
Fig 7 schematically illustrates the Spindle Kinematic drawing of the
Milling and Boring Machine according to the present invention.
Fig 8 schematically illustrates the Rack And Pinion Drive drawing of the
improved Milling and Boring 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.
According to a preferred embodiment of the present invention as shown in fig 1(a), 1(b) and 1(c) the Milling and Boring Machine offers a Machining Zone of 1500x1500x1250 mm. High end performance is ensured by using stress relieved rigid cast iron ribbed structures for Machine Bed (1), Saddle (2), Column (4), Spindle head(5) and Rotary Table (6). These machines are equipped with precision hardened and ground ball screws and linear motion guide ways for excellent positional accuracy and repeatability.
Rapid traverse rate of X, Z axes are 6000 mm/min and Y, W axes are 1000 mm/min. For accurate, cost effective and high speed machining, the said machine has balanced spindle with set of precision bearings grease lubricated for life. To secure better machining parameters, the machines are equipped with gear box and the spindle drive with spindle cooling Unit. It uses 40 Tool chain type Tool Magazine having least tool changing time. Chip conveyor (8) system having efficient swarf disposal is

placed in front of the machine Bed(l) to collect chips directly from machining zone. The said machine is designed considering compact foot print, better ergonomic and environment friendly.
The present invention facilitates a dedicated Horizontal Machining Center which can perform various operations on same machine. In addition to that boring spindle which is located in milling spindle can perform the boring operation on the component with the better accuracy. The salient features of Head stock (5) are mentioned in brief.
The construction of bearing arrangement for Milling Spindle housed in Head stock (5) is typically designed with super precision angular contact ball bearings mounted back to back and cylindrical needle roller bearing suitably preloaded to accommodate maximum possible cutting forces to maintain precision and achieving reliability. The Boring Spindle (Quill) rotates along with Milling Spindle and slides on a special non-ferrous (Aluminum Bronze) bushing inside the Milling Spindle. Quill alignment is effected through precision taper bush in front of the spindle.
The material of rigid Milling and Boring Spindles is specifically selected as nitriding steel to have zero distortion, during heat treatment process. The Boring Spindle rotates at 15 to 1500 rpm with minimum run out during full Quill traverse
The Spindle is driven by Spindle motor through 2-stage Gear Box. The Gear Box is specially equipped with precision ground nitrided gears. The travel of quill is through precision ground Ball Screw having high lead accuracy with nut bracket guided in Linear Hydrostatic Bearing.
The Spindle unit is equipped with through tool coolant arrangement facilitating effective chip removal. This is in addition to standard Flood Coolant, Jet Coolant. The tool clamping is done by Belleville Springs (Disc Springs) and de-clamping through Hydraulic Cylinder.

A separate Spindle Cooling arrangement is provided for Head Stock (5) Unit to overcome the heat generation during continuous running of Milling and Boring Spindle. Appropriate provision is made for lubrication of Bearings, Gears and Ball-Screw for smooth working and long life.
The Quill and Milling Spindle assembly is done with utmost care using sophisticated methodology to reduce vibrations, enhance rigidity and control thermal distortion thus achieving desired performance of Spindle.
Rigid tapping feature is provided using Precision Encoder.
Major Technical Specifications of Quill type Head Stock (5) unit:

Specification Unit Value
1) Boring Spindle Diameter mm Dia 130
2) Spindle Nose Taper — ISO-50
3) Spindle Speed rpm 15-1500
4) Maximum travel of quill mm 500
5) Spindle power (Continuous/30 min rating) kw 30/37
The Travelling Column CNC Milling and boring Machine includes cast iron ribbed Machine Bed (1), Column (4), Saddle (2) and a hydrostatic NC Rotary Table (6). The most important part of the machine is Head Stock (5) with quill as discussed.
Normally Head Stock (5) is equipped with Milling Spindle. However to meet the Deep Boring requirement on components the Horizontal Machining Center with traversing type precision Boring Spindle (Quill), which is co-axially mounted in

Milling Spindle is most effective. This quill movement is through hydrostatic guide with preloaded ball screw driven by servo motor.
Horizontal Machining Centers (HMC's) are used to perform multi operations like milling, drilling, boring in single setup. The machine has large machining capacity to remove desired material from the work piece at high accuracy with less cycle time. This machine has built in boring spindle and milling spindle to execute requirement of deep boring operation with higher accuracy. The variety of cutting tools is automatically picked from the spindle through system controls in minimum tool changing time. In addition to the above perpendicular operations will be done through Universal Milling Attachment.
The improved Travelling Column CNC Milling and Boring machines is designed to get high accuracy on machined component with less cycle time and high productivity. The heavy robust cast iron structure makes these machines suitable for large cutting forces and vibrations during machining. These machines can work efficiently and effectively even for high production application as it is required by the changing industrial demands.
Horizontal Milling and Boring machines are intended for massive and heaving duty operations. Even the most difficult odd boring jobs can be performed with higher level of accuracy.
Horizontal Machining Centres are generally adapted to produce a wide range of applications. A wide variety of operations are performed with the number of cutters interchanged with the chain mounted ATC (7). While the conventional machining centers has the x-axis driven by the conventional method like ball screw and servo motor, this invention have developed for large stoke X- axis movement using precision rack and pinion (2.1 to 2.5) arrangement. To reduce backlash the appropriate preload is considered to the slit type pinion with required lubrication for smooth running.

To meet high material removal rate and to achieve high production rate with the high spindle power and torque spindle with two stage reduction gear box driven by CMC spindle motor is developed. Also for better rigidity highly ribbed structure to overcome the large cutting forces and vibrations generated at the time of machining has been developed. Proper hydraulic circuit is designed to overcome extra heating of the oil.
To get high productivity the component machining face is indexed through CNC table provided in front of the spindle. Spindle will receive variety of tools based on the program made for particular component. In single set up five faces machining can be made in the Travelling Column CNC Milling and Boring of the present invention which are as follows:
Machining Types:
Drilling Operation Boring Operation End Milling Operation Face Milling Operation Rimming Operation Tapping Operation
Various types of machining operations can be performed using required type of tool with the appropriate cutting parameters.
The machining center is designed dedicated to the manufacture variety of jobs with the usual requirements of a high accuracy and for high production. The Main Bed (1) is rigidly placed on the ground with the suitable foundation (13). Saddle (2) is moving over the Main Bed (1) and which is driven by the rack and pinion (2.1 to 2.5 shown in Fig 5a) drive and the servo motor. Column (4) is mounted on Column Base (3) which slides over Saddle (2) and the drive is form servo motors. Head stock (5) is moving on highly ribbed and thermo-symmetrically balanced Column(4). All these

axes are with hardened and ground LM guide ways to minimize the friction between the moving parts. Figure la further illustrates the position of the ladder (9) and chip trolley (8.1). Figure lb additionally points out the hydraulic manifold (10.1), pendant (12), and control panel (11) of the milling and boring machine as disclosed. Figure lc illustrates the position of coolant filtration unit (14), hydraulic cylinder for balancing (15), operator platform (16), voltage stabilizer (17), transformer (18), cladding (19) and hydraulic power pack (10).
Hydraulic power pack (10) is designed in such a way that it ensures the smooth running of machine during operation. Oil cooling unit is providedl to avoid the heating of hydraulic oil in power pack. Two separate motors are provided to carter the required oil for ATC (7) function and machine related functions. Hydraulic manifolds provided for vertical movement of Head stock (5) through hydraulic balancing cylinder (15) and tool de-clamp from spindle. Also there are two separate power packs for Rotary Table (6), one is used for hydrostatic lift of the table and other is used for table clamping.
Slat type Chip conveyor (8) is designed to carry maximum chips collected during component machining. Slat type Chip conveyor (8) is very suitable to carry curly type chips produced during steel component machining and it is placed in front of the Machine Bed (1). Coolant Tank has sufficient capacity to carry chips from machine Bed (1) to Chip conveyor (8).
Main Electrical Control Panel (11) is mounted on right side of machine. Swivel type operator pendent box is mounted in front of the machine at right side for ease reach of operator and better Ergonomics.
Fig. 2 and 7 illustrate the Head Stock assembly (5) of the Travelling Column CMC Milling and Boring Machine according to the present invention. Fig 4a and 4b schematically illustrates the Milling and Boring Spindle Assembly of the improved Milling and Boring Machine according to the present invention. Y axis ball screw has

high precision, large size bearings provided for good repeatability and high rapid travels. Ball Screw bearings and ball screw nut is periodically lubricated through centralized lubrication system which is mounted on hydraulic power pack (10). Ball screw is supported with the ball screw support bearing on both ends and is driven by servo motor with the brake. The w-axis movement is through high precision ball screws and servo motor coupled through set of pulleys and belt. The following reference numerals illustrates the position of the following parameters as listed below in said figure 2,4a, 4b and 7: 5 Milling and boring spindle assembly
5.2 Spindle housing
5.3 Spindle nose
5.4 Rear housing
5.5 Tennons
5.6 Adaptor plate
5.7 Coolant nose
5.8 Ball screw for quill
5.9 Quill motor
5.10 LM block
5.11 Spindle motor
5.12 Pulley (64 teeth)
5.13 Timer belt
5.14 Pulley (44 teeth)
5.15 Moving bracket for quill
5.16 Milling spindle
5.17 Boring spindle
5.18 Cylindrical roller bearings

5.20 Angular contact bearing
5.21 Oil tank
5.22 2-stage gear box
5.23 Head stock quill
5.24 Ball screw for quill

5.25 Hydraulic cylinder
5.26 Encoder assembly
5.27 Coolant Union
5.28 Disc springs
5.29 Cable drag chain
5.30 Milling spindle
5.31 Boring spindle
5.32 Spindle motor
5.33 Ball screw (in fig 5(d))
5.34 Servo motor (in fig 5(d))
N C Rotary Table (6) which is driven by the worm and worm wheel through servo
motor. Rotary Table (6) has hydrostatic lift for rotation of the table. Precision bearing
is provided on center of the Table for Table rotation. Fig 3 and Fig 6 will illustrate
details of Rotary Table (6). This invention has the table of 1500x1500 swings with an
accuracy of 0.001 degrees. This is achieved by the Hollow shaft encoder. Rotary
Table has a hydrostatic LUCAS unit to control the flow of the oil to get the equal lift
on the table. Figure 3 and figure 6 illustrates the N C table assembly of the improved
milling and boring machine as disclosed in the present invention. The following
reference numerals are used to represent the following features in the said figure as
listed below:
6 Rotary table
6.1 Bottom table
6.2 Table motor
6.3 Hydrostatic Lucas Unit
6.4 Main Base
6.5 Servo motor 6.6/6.9 Worm shaft 6.7/6.8 Worm wheel

Fig 5 (a, b, c, d) illustrate the drive assembly for the all axes. Head stock which has arrangement of Milling and Boring Spindles, which has hydrostatic guide ways for quill movement. Spindle has two stage reduction gear box and it is driven by the spindle motor. Quill movement is by servomotor through set of pulleys and timer belt.
Fig 8, 5(a) schematically illustrates the X-axis rack and pinion drive (2.1 to 2.5). This invention is adopted for high accuracy and for larger stroke of application. To achieve the zero backlash slit type pinion is use and for minimum friction between pinion and rack lubrication system is introduced with the exact amount of the oil supply. The following reference numerals are used to represent the following features in the said figures as listed below: 2 Saddle
2.1 Rack
2.2 Splitted pinion
2.3 Felt Pinion
2.4 Gear Box
2.5 Output shaft
2.6 Servo motor
Fig 5 (b) illustrate schematically the drive mechanism for Y axis, where drive is given by servomotor (4.1) and it is coupled with precision ball screw (4.2).
Fig 5 (c) illustrate schematically the drive mechanism for Z axis, where drive is given by the servo motor (3.1) with brake and it is coupled with the precision ball screw(3.2) through the direct drive(3.3).
Fig 5 (d) illustrates schematically the drive mechanism for W axis, it driven by the servo motor (5.34) and it is coupled with the precision ball screw through set of pulleys (5.12 and 5.14) and timer belt(5.13).

Fig 7 illustrates schematically the Spindle Gear train assembly. The present invention has two stage reduction gear box to get the maximum power and maximum torque at spindle for various operations.
AH 3 axes are completely protected by steel covers,and form the ingress of chips and coolant. Apart from increase life of the machine/ this also helps in separating critical machining elements like ball screw, LM, linear scales etc. form the hot chips. Totally enclosed splash guard is available for complete protection of the operator from the chips, coolant mist etc. It is also used for incorporating the jet coolant system.
The operator panels are separately installed at positions most convenient for operation purpose push button or these panels are all laid out systematically possible operation errors. The display shows current position, tool offset, program data and variety of NC self-diagnostic functions for effective checkup. The present invention represent an advance over machines of the prior art by providing a mechanically stiffer machine exhibiting improved dynamic characteristics. The invented machine can be made more reliable than the machine of the prior art.
The present invention has been described with reference to some examples 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 scope of what has been described hereinbefore and claimed in the appended claims.

WE CLAIM:
1. A Travelling Column CNC milling and boring machine comprising, at least one machine bed (1), a saddle(2), a rotary table assembly(6)/ and a column (4) mounted on said machine bed, a head stock assembly(5) housed inside said column, and a control panel equipped with an electronic calculating means for monitoring the entire milling process.
2. The Travelling Column CNC machine as claimed in claim 1, wherein said head stock assembly (5) comprises a spindle motor housed in a spindle housing, a quill motor housed in a rear housing, a nose block housing a milling and boring spindle assembly, and a plurality of pulleys and timer belt.
3. The Travelling Column CNC machine as claimed in claim 1, wherein said rotary table assembly comprises a main base, a table motor, a hydrostatic Lucas unit, a bottom table and a rotary table driven by said motor.
4. The Travelling Column CNC machine as claimed in claim 1, wherein said saddle (2) comprises, rack and pinion (2.1 to 2.5) drive for X-axis and a gear box for higher reduction and the maximum torque
5. The Travelling Column CNC machine as claimed in claim 1, wherein said column (4) is a thermo-symmetric cast member which can be mounted on column base(3).
6. The Travelling Column CNC machine as claimed in claim 1, wherein said milling and boring machine comprises a travelling column CNC milling and boring machine.
7. The Travelling Column CNC machine as claimed in claims 1 and 2, wherein said spindle is turned at a rate of at least 15-1500 revolutions per minute.

8. The Travelling Column CNC machine as claimed in claim 1, wherein said NC Rotary Table (6) is hydrostatically operated.
9. The Travelling Column CNC machine as claimed in claim 1, wherein said machine comprises a separate Coolant tank, Chip trolley and Slat type chip conveyor (8) for the removal of chips.
10. The Travelling Column CNC machine as claimed in claim 1, wherein said machine comprises a machine guard designed in terms of the ergonomic considerations and operators safety.