FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A ROTOPAINTING MACHINE FOR PAINTING STORAGE WATER HEATER
TANKS
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Joshi Sachin Sharad, Nadar Vinay Velayutham and Ingie Asha Jayaprakash of Crompton Greaves Ltd, AMPTC, Global R&D Centre, Kanjur (E), Mumbai 400042, Maharashtra, India; all Indian Nationals
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to a rotopainting machine. Particularly, the present invention relates to a rotopainting machine for painting the inner surface of tanks, such as storage water heater tanks.
The present invention also relates to a method of painting the inner surface of a storage water heater tank using the rotopainting machine of the present invention.
BACKGROUND OF THE INVENTION
In domestic storage water heater, the inner container is made up of mild steel.
Mild steel by nature is corrosive but is still preferred for its cost and pressure resistant advantage, in order to make it resistant to corrosion, it has to be protected by paint or a layer of coating that isolates the steel from the environment. This coating could be epoxy paint, powder coating or glass lining.
Powder coating is a type of coating that is applied as a free-flowing, dry powder. It creates a professional-looking finish on steel and other metal surfaces.
Another approach for protecting the inner surface of the water heaters is to make use of glass lining on the inside to help prevent corrosion. While a glass lining mostly protects the steel from rusting, due to limitations in manufacturing process there is always some exposed steel.
Epoxy paint coatings have proven to be the solution to some of industry's most persistent corrosion problems. They are tough, durable resin system that protects the equipment and the surfaces in extremely corrosive environment. Furthermore, liquid epoxy paint gives a cost advantage over powder coating and glass lining.

It may be noted that though there are techniques available to protect the steel or other substance from corrosion, the domestic storage water heater wherein the inner surface of the geyser tank is made up of steel and has an opening of 72mm diameter makes it impossible to paint the inner surface. It is not feasible for a person to insert his hand and paint it. Therefore, there is a need of a unique and effective rotopainting machine to paint the inner surface of the domestic storage water heater tanks.
A rotary painting machine having a number of barrels for holding parts to be painted is disclosed in US Patent No. US4616593A. However, it deviates in terms of construction and method of painting with respect to the present invention.
Thus, there is a continuing need for a rotopainting machine for uniformly painting the inner surface of the domestic water heater storage tank made up of mild steel in reduced amount of time to provide resistance to corrosion.
OBJECTIVE OF THE INVENTION
An object of the invention is to provide a rotopainting machine for painting the inner surface of storage water heater tanks.
Another object of the invention is to provide a method of painting the inner surface of the storage tank of domestic water storage heater using rotopainting machine of the present invention,
An object of the present invention is to provide a method of painting the inner surface of the domestic water storage heater which uniformly paints the inner surface in a reduced time.
SUMMARY OF THE INVENTION
A rotopainting machine comprising:
a supporting frame having a pair of vertical supporting structures;

a horizontal frame pivotably connected to the pair of vertical supporting
structures, the horizontal frame having a front wall and a rear wail, and a plurality
of having connection ports;
a plurality of tank holding structures for supporting a plurality of tanks, wherein
the plurality of tank holding structures are rotatably connected to the horizontal
frame;
a first driving motor for rotating the plurality of tank holding structures along a
first axis of rotation; and
a second motor for pivoting the horizontal frame along a second axis of rotation,
wherein the second axis of rotation is perpendicular to the first axis of rotation.
A method of painting an inner surface of a tank comprising the steps of:
loading at least one of a plurality of tanks with a predetermined quantity of paint; securing the tank in a horizontal position into a tank holding structure, wherein the tank holding structure is disposed on a horizontal frame ; rotating the tank holding structure along a first axis of rotation by a first driving motor;
maintaining the horizontal frame in a first horizontal position for a predetermined period of time;
pivoting the horizontal frame along a second axis of rotation and in a first direction to move the horizontal frame from a first horizontal position to a second position by a second driving motor;
maintaining the horizontal frame in the second position for a predetermined time period; pivoting the horizontal frame along the second axis of rotation and in a second opposite direction to move the horizontal frame from the second position to a third position with the second driving motor; and
maintaining the horizontal frame in the third position for a predetermined period of time.
BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a perspective view of the rotopainting machine according to the present
invention.
FIG. 2 illustrates a top view of the rotopainting machine according to the present
invention.
FIG. 3 illustrates a left side of the rotopainting machine according to the present
invention.
FIG. 4 illustrates the front view of the rotopainting machine according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. land FIG. 2, the rotopainting machine (1) according to the present invention includes a frame (2) having a pair of vertical support structures (3). Each of the support structures (3) has a connecting port (4) disposed at the top end. Further, the machine has a horizontal frame (5) disposed at the top end of the frame (2) which is supported by the pair of vertical support structures (3). The horizontal frame (5) is pivotably connected to the connection port (4) on the support structure (3) and pivots about the axis 21-21' as shown in FIG. 2. The horizontal frame (5) has a front wall (6) and a rear wall (7). The front wall (6) has a plurality of connection ports (8a), (8b), (8c), (8d), and (8e) respectively.
Further, the rotopainting machine according to the present invention includes a plurality of tank holding structures namely, (9a), (9b), (9c), (9d) and (9e) respectively to which enclose the plurality of tanks (12a), (12b), (12c), (12d), and (12e) respectively. Each tank holding structure (9a) through (9e) includes a pair of tank holding plates (10) separated by a plurality of rods (11) which surround and support the plurality of tanks (12a) to (12e) enclosed within the tank holding structures (9a) to (9e) respectively.
The tank holding structures (9a) through (9e) are disposed in a horizontal orientation between the front wall (6) and the rear wall (7) of the horizontal frame (5), in a linear array. Further, the tank holding structures (9a) through (9e) respectively are rotatably connected to the connection ports (8a) through (8e) respectively. Each holding structure

rotates about an axis of rotation 22-22' as shown in FIG. 2, which is perpendicular to the pivoting axis 21-21'.
Further, the rotopainting machine has a first driving mote"' (13) disposed on a supporting structure (18). As shown in FIG. 3, the first driving motor (13) is connected by a chain (16) to a sprocket (15) disposed on the horizontal frame (5)- When the first driving motor (13) rotates, the sprocket (15) meshes with the chain (10) and causes the rotation of the tank holding structures (9a) through (9e) about the axis of rotation 22-22'.
The tank holding structures (9a) through (9e) rotate about the axis 22-22' at a speed of about 24 RPM. The rotopainting machine includes a gear box (not shown) to regulate the speed of rotation.
As shown in FIG. 4, a second motor (14) is disposed on a supporting structure (19)
to a chain (17) and causes the horizontal frame (4) to pivot about the axis 21-21'.
The angle of rotation of the horizontal frame (5) ranges from 45° to 55° when the frame (5) pivots about the axis 21-21'.
In another aspect, the present invention relates to the method of an inner surface of a tank. The method according to the present invention comprises loading at least one of the plurality of tanks (I2a) through (12e) with a predetermined quantity of paint. The quantity of paint may be 100ml to 600ml. Further, the suitable types of paint may include any liquid paint. The tank is then sealed and secured to the tank holding structures (9a) through (9e) disposed on the horizontal frame (5), where it is enclosed within the supporting plates (10) and the plurality of rods (11) and maintained in a horizontal position. At this time, the horizontal frame (5) is maintained in a first horizontal position for a time period of about 2- 5 minutes. The tank holding structures (9a) through 9(e) are then rotated about the axis 22-22', in a horizontal direction by the first driving motor (13) for a about 5 minutes. The horizontal frame (5) is then pivoted along the axis 21-21' by the second motor (14), in order to move the frame 0) in a first direction towards a

second position. The angle of rotation of the horizontal frame (5) necessary to move the frame (5) from a first horizontal position to a second position ranges from 45°to 55°. The frame (5) is maintained in the second position for about 2 to 5 minutes. Further, the frame (5) is then pivoted by the second motor (14) in a second opposite direction to a third position. The frame (5) is maintained in the third position for about 2 to 5 minutes. The angle of rotation of the horizontal frame (5) necessary to move the frame (5) from the second position to a third position ranges from 45° to 55°.
The rotopainting machine of the present invention may include conventional controllers (not shown) to regulate the time period for maintaining the frame (5) in each of the above-mentioned positions.
The rotation of the tank holding structures (9a) through (9e) in a horizontal direction along the axis 22-22' by the first motor (13) and the simultaneous sequential movement of the frame (5) to a first, second, and third position by the second motor (14) allows the paint contained inside the tank to distribute evenly and form a uniform coating on the inner surface of the tank. Also, the method of painting reduces the amount of time required for painting the inner surface of the tank.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.

We claim,
1) A rotopainting machine comprising:
a supporting frame having a pair of vertical supporting structures;
a horizontal frame pivotably connected to the pair of vertical supporting
structures, the horizontal frame having a front wall and a rear wall, and a plurality
of having connection ports;
a plurality of tank holding structures for supporting a plurality of tanks, wherein
the plurality of tank holding structures are rotatably connected to the horizontal
frame;
a first driving motor for rotating the plurality of tank holding structures along a
first axis of rotation; and
a second motor for pivoting the horizontal frame along a second axis of rotation,
wherein the second axis of rotation is perpendicular to the first axis of rotation.
2) The machine of claim 1, wherein the tank holding structures consist of a pair of tank holding plates separated by a plurality of rods for supporting the tanks.
3) The machine of claim 1, wherein the plurality of tank holding structures are disposed between the front wall and the rear wall of the horizontal frame.
4) The machine of claim 3, wherein the plurality of tank holding structures are disposed in a linear array and in a horizontal orientation.
5) The machine of claim 1, wherein the angle of rotation of the horizontal frame along the second axis ranges from 45°to 55°.
6) A method of painting an inner surface of a tank comprising the steps of: loading at least one of a plurality of tanks with a predetermined quantity of paint; securing the tank in a horizontal position into a tank holding structure, wherein the tank holding structure is disposed on a horizontal frame ;

rotating the tank holding structure along a first axis of rotation by a first driving
motor;
maintaining the horizontal frame in a first horizontal position for a predetermined
period of time;
pivoting the horizontal frame along a second axis of rotation and in a first
direction to move the horizontal frame from a first horizontal position to a second
position by a second driving motor;
maintaining the horizontal frame in the second position for a predetermined time
period; pivoting the horizontal frame along the second axis of rotation and in a
second opposite direction to move the horizontal frame from the second position
to a third position with the second driving motor; and
maintaining the horizontal frame in the third position for a predetermined period
oftime.
7) The method of claim 6, wherein the quantity of paint is from 100 to 600 ml.
8) The method of claim 6, wherein the angle of rotation of the horizontal frame from the first position to the second position ranges from 45°to 55°.
9) The method of claim 6, wherein the angle of rotation of the horizontal frame from the second position to the third position ranges from 45°to 55°.
10) The method of claim 6, wherein the horizontal frame is maintained in the first position for a time period of 2 minutes to 5 minutes.
11) The method of claim 6, wherein the horizontal frame is maintained in the second position for a time period of 2 minutes to 5 minutes.
12) The method of claim 6, wherein the horizontal frame is maintained in the third position for a time period of 2 minutes to 5 minutes.

13) The method of claim 6, wherein the tank holding structure is rotated about the first axis at a rate of 24 RPM.
14) The method of claim 6, wherein the paint is in the form of liquid.
15) The method of claim 6, wherein the first axis of rotation is perpendicular to the second axis of rotation.