FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"POT GUN STIRRER FOR PAINT TOUCH UP"
MAHINDRA & MAHINDRA LIMITED
A COMPANY REGISTERED UNDER THE
PROVISIONS OF COMPANIES ACT, 1956
HAVING ADDRESS AT
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C, SATPUR,
NASHIK-422 007,
MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION:-
The present invention is related to paint spray gun used for Paint touch up in the Automobile Industry. More particularly, the present invention is related to the improvements in pot gun lid for the purpose of stirring the paint by providing an unique stirrer therein.
BACKGROUND OF THE INVENTION:-
Vehicle bodies are generally painted with the spray painting application wherein pot guns are used for touch up activities. In this pot gun, a source of air under pressure is passed through a nozzle whereby a vacuum is created that aspirate the paint from a source adjacent the gun to the work surface.
In many paints particularly having a metallic pigment, there is a strong tendency for the pigment particles to settle in the liquid, resulting in an inconsistent and unsatisfactory application of the paint over the body surface.
Efforts have been made to keep such pigment suspended uniformly throughout the paint during the paint application. Prior art document no. US3042310 describes hand paint spray gun agitator which is actuated by the same pressure means which actuates the paint spraying means for the gun.
The drawback of this prior art is that it requires fix air hose requirement for the paint stirring and further requires extra attachment on the paint rework gun that lead to increase the weight of the gun during the touch up operation. Another drawback is that it has no flexibility towards the multi color selection as the agitator is mounted inside the colour cup to be attached to the gun during the operation. For cleaning purpose, colour pot requires dismantling of the unit.
Another document no. US 4401268 disclose spray gun with paint agitator wherein a paint supply container has a motor driven agitator means for automatically mixing the paint in the container.

The drawback of this prior art is that the stirrer is operated by motor and it is gun mounted. Further, it requires fix air hose requirement for the paint stirring and further requires extra attachment on the paint rework gun that lead to increase the weight of the gun during the touch up operation. Further, it is a side mounted stirrer wherein a single blade is provided at the bottom only. Therefore, thorough stirring cannot be ensured.
OBJECT OF THE PRESENT INVENTION:-
The main object of the present invention is to provide a simple and cost effective stirrer mechanism to the pot gun lid.
Further object of the present invention is to provide a simple stirrer mechanism to the pot gun lid which is fully adaptable to the standard paint guns available in the market with no modifications required to attach it.
Another object of the present invention is to keep the paint pigment suspended within a paint while the pot gun is in standstill condition.
Still another object of the present invention is to eliminate the possibility of running out of paint through a critical area and risk of having a change in colour tone at the run out point.
Still further object of the present invention is to reduce the preparation time prior to painting and thus impart more on-the-job painting leading to increase in worker productivity.
STATEMENT OF fNVENTION:-
Accordingly the invention provides a pot gun stirrer for paint touch up comprises housing (2) having a housing cover (8) incorporating a covering plate (9); a bearing (10) fitted inside the said covering plate (9) with the help of suitable seals (11); a bearing plate (12) having a projected portion fitted to the said bearing (10) through its projected portion (15) which fits inside the bearing; a

rotor housing (13) is fitted to the bearing plate (12) through its projected stud (14) which gets locked inside the opening (16) provided on the bearing plate (12); an inlet adopter is provided to the said housing cover for pneumatic air supply; a rotor fitted inside the said rotor housing (13) with locking; a pot lid (3) is attached to the housing (2) with the help of brackets (7); a stirrer shaft provided with stirring blades fitted to the output shaft, protruding out of said pot lid, of the said rotor; a color pot, filled with metallic paint (20) of the touch up pot gun (22), top open engaged, by screwing, to the said pot lid fitted with housing of the stirrer assembly.
DESCRIPTION OF THE FIGURES:-
Figure 1 shows perspective view of the pot gun stirrer arrangement in accordance with the present invention.
Figure 2 shows assembly diagram of rotor housing and other components to be fitted inside the housing.
Figure 3 shows the stirrer shaft with the stirring blades.
Figure 4 shows the pot gun stirrer assembly of the present invention attached to the touch up gun with colour pot placed in standstill condition on the stand during the stirring operation.
Figure 5 shows the cross sectional view of the whole assembly as shown in figure 4.
DESCRIPTION OF THE INVENTION:-
Referring to figure 1, pot gun stirrer assembly (1) comprises of a housing (2), pot lid (3), stirring shaft (4) and stirring blades (5) attached to the shaft (4). The pot lid (3) is attached to the housing (2) with the help of brackets (7). The housing (2) further comprises of housing cover (8) wherein the said housing cover incorporates covering plate (9), bearing (10), wherein the said bearing (10) is

fitted inside the covering plate (9) with the help of suitable seals (11) as shown in figure 2. The bearing plate (12) is fitted to the bearing (10) through its projected portion (15) which fits inside the bearing. The rotor housing (13) is fitted to the bearing plate (12) through its projected stud (14) which gets locked inside the opening (16) provided on the bearing plate (12). The rotor (not shown in the figure) is incorporated and fitted inside the rotor housing (13) with suitable means and gets locked.
Referring to figure 3, the shaft (17) of the stirrer is fitted to the output shaft of the rotor protruding out from the pot lid (3) with the help of suitable means and most preferably with nut. The blades (5) are attached securely to the stirrer shaft (17) with the help of nuts (18). The said blades are spaced apart by 35 mm to attain the thorough stirring of the colour pigments in an average sized colour pot. Further, the said blades are at an angle of 30 to 45 degrees to ensure the thorough stirring of the colour pigment and avoid the settlement of metallic particles prior to the touch up operation.
The pot lid (3) of the stirrer assembly is made up of generally available PVC material. The bracket (7) is made of mild steel material and the housing cover is made of suitable composite material to make the whole assembly light in weight. The stirrer shaft is made of stainless steel material and the stirring blades are made of aluminum to have the effective stirring of the metallic colour pigment and avoid settling of the particles at the bottom.
The stirring activity happens when a touch up gun with colour pot attached, is put in stand-still condition as shown in figure 4. The rotor inside the housing (2) is rotated by the pneumatic air source supplied through the conduit (6). The figure 4 shows the pot gun stirrer assembly of the present invention attached to the touch up gun (22) with colour pot (20) placed in standstill condition on the stand (21). The stirring arrangement of the invention work on low air pressure that is 1 bar.
Working of the stirring attachment of the invention is explained as follows. After metallic paint filled in the colour pot (20) of the touch up pot gun (22), the stirrer

assembly is mounted on the pot. The stirrer assembly generally fitted on the wall wherein the touch up guns are put after the touch up work. Once the stirrer assembly is engaged with the touch up gun, the pneumatic source is put on which drives the rotor of the stirrer assembly. Since the stirring blades through the shaft are attached to the rotor, these blades also starting rotating when the rotor starts and stirring operation is done.
The advantages achieved / derived from the stirring mechanism of the present invention are as under.
- Portability - Can be used anywhere by taking pneumatic air supply for the automotive body metallic paint repair.
- Adaptability - Suits for all types of metallic colors use for paint application on the automobile body.
- Reusable -Stirrer can be clean and can be use again and again.
- Shade Mismatch concern eliminated for the metallic colors.
- Paint wastages saved approx.2 Liter/day.
- Repair Time reduced by 50 %.
- It's an environment friendly simple and low cost stirring arrangement.
- No Fix air hose connection is required for the paint stirring and continuous paint stirring is possible through this.
- It leads to the stirring of the paint when the gun is in no operation condition and is mounted on the top of the Gun whereas the conventional systems have suction feed, side mounted cup.
- It requires low air pressure that is 1 bar for its working.
- No extra attachment is needed on the paint rework gun as compared to the prior art solutions.
- It is easy to clean whereas the prior art stirrers are difficult and huge amount of thinner is required for cleaning. Further, no gun dismantling is require for cleaning as that of prior art systems.
- Easy for handling due to less weight.

WE CLAIM:-
1. A pot gun stirrer for paint touch up comprises housing (2) having a housing cover (8) incorporating a covering plate (9); a bearing (10) fitted inside the said covering plate (9) with the help of suitable seals (11); a bearing plate (12) having a projected portion fitted to the said bearing (10) through its projected portion (15) which fits inside the bearing; a rotor housing (13) is fitted to the bearing plate (12) through its projected stud (14) which gets locked inside the opening (16) provided on the bearing plate (12); an inlet adopter is provided to the said housing cover for pneumatic air supply; a rotor fitted inside the said rotor housing (13) with locking; a pot lid (3) is attached to the housing (2) with the help of brackets (7); a stirrer shaft provided with stirring blades fitted to the output shaft, protruding out of said potl lid, of the said rotor; a color pot, filled with metallic paint (20) of the touch up pot gun (22), top open engaged, by screwing, to the said pot lid fitted with housing of the stirrer assembly.
2. The pot gun stirrer as claimed in claim 1 wherein the said stirrer blades (5) are attached securely to the stirrer shaft (17) with the help of nuts (18).
3. The pot gun stirrer as claimed in claims 1 and 2 wherein the said blades are spaced apart by 35 mm to attain the thorough stirring of the colour pigments in an average sized colour pot.
4. The pot gun stirrer as claimed in claims 1 to 3 wherein further, the said blades are at an angle of 30 to 45 degrees to ensure the thorough stirring of the colour pigment.
5. The pot gun stirrer as claimed in claims 1 to 4 wherein the said pot lid made of PVC material.
6. The pot gun stirrer as claimed in claims 1 to 5 wherein the said bracket is made of mild steel.

7. The pot gun stirrer as claimed in claimsl to 6 the said housing cover is made of composite material.
8. The pot gun stirrer as claimed in claims 1 to 7 wherein the said stirrer shaft made of stainless steel and stirring blades are made of aluminum.
9. The pot gun stirrer as claimed in claims 1 to 8 wherein the said rotor is operable at one bar pressure air supply.