FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
[See section 10, rule 13]
"SEALANT DISPENSING SYSTEM"
NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS LIMITED, an Indian company having its registered office at Bombay
house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA.
Nationality: Indian
The following specification describes the invention,

TECHNICAL FIELD
The present invention generally relates to industrial robots used for applying sealants and more particularly relates to a sealant dispensing system carried by an industrial robot.
BACKGROUND OF THE INVENTION
In automobile industry, sealants are used for joining or sealing a work piece such as doors, hoods, trunks or any such automobile body part. The sealants help in producing waterproof, air-tight and vibration isolating joints which are critical for an automobile. The sealants are chemical compounds of extremely high viscosity, being nearly rigid at room temperature, and often require high operating pressures and thermal conditioning to achieve and maintain a desired flow. Conventionally, a sealant pump distributes pressurized sealant to a sealant distribution hose, upon receiving a signal from a sealant controller. The sealant distribution hose of the sealant is laid on an assembly line up to various terminals where robotic machines, such as an industrial robot, apply the sealant at predetermined locations on the automobile body parts. Since the sealant is typically required to be applied in a fairly intricate, tightly controlled pattern, the six degrees of motion of arms of the industrial robot is well suited.
In typical arrangements, thick, heavy, semi-rigid sealant distribution hose are coupled to the robot arms and they run along the length of the robot arm to supply sealant to doser assemblies. Encoder cables connect encoder, carried by the doser, and communicate with the sealant controller to provide the sealant to the doser when required. Sealant hose extends from each of the dosers to sealant guns, to dispense sealant therefrom.
However, in such typical arrangements, the doser along with the nozzle, the encoders, the proportional valves and the fill valves, are carried by forearm end of the robot arm. As the forearm of the robot arm has a wide range of motion, the cables such as encoder

cable, pneumatic cable and the sealant hose also has to be extended, retracted, twisted, turned and dragged around as the robot arm moves the nozzle ( also known as "sealant guns") over the work piece. It therefore becomes difficult to prevent the cables from being dragged or rubbed against the robot arm and the doser.
Various problems arise in these typical arrangements, such as but not limited to breakdown of encoder cables and encoder, improper quantity of dispensing, entangling and breakdown of sealant hoses.
OBJECTS OF THE INVENTION
The objective of invention is to provide a reliable, simple and economical sealant dispensing system.
Another object of the invention is to reduce breakdown time of an industrial robot by provide a sturdy sealant dispensing system.
Yet another embodiment of the present invention is to provide a sealant dispensing system in which none of the dosers are carried by forearm of an industrial robot.
Another embodiment of the present invention is to minimize undesired movement of the cables such as the encoder cable thereby reducing breakdown thereof.
Further objects and features of the invention will become apparent from the following detailed description when considered in conjunction with the drawings.
SUMMARY OF THE INVENTION
The various embodiments of the present invention disclose a sealant dispensing system for an industrial robot having a forearm, a first wrist member rotatably joined to said forearm, and a second wrist member rotatably joined to said first wrist member. The

sealant dispensing system includes a doser assembly capable of storing pressurized sealant; a doser assembly mounting connected to said first wrist member, and configured to carry said doser assembly; a distributer block carried by said forearm; a sealant gun connected to said forearm; and a sealant hose extending from said doser assembly and connected to said distributer block. The sealant hose is configured to carry sealant from said doser assembly. The sealant dispensing system further includes a sealant distributor hose connected to said distributer block and said sealant gun. The sealant distributor hose is configured to transport said sealant from said distributer block to said sealant gun.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a view of a sealant dispensing system for the industrial robot, according to an embodiment of the invention,
FIG. 2a illustrates a front view of a portion of the sealant dispensing system of FIG. 2, according to an embodiment of the invention, and
FIG. 2b illustrates a front view of a doser assembly mounting of the sealant dispensing system of FIG. 1, according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
FIG. 1, 2a and 2b illustrates a sealant dispensing system 200 for an industrial robot 100 according to present invention. The industrial robot 100 may be any multi-axis robot having a varying numbers of axes or degrees of motion, for example a six-axis robot. Typically, the industrial robot 100 is used as a guide while dispensing high viscosity, pressurized, temperature conditioned structural sealant from a sealant gun onto a work

piece (not shown) such as an automobile door panel, a hood panel, a trunk panel and the like.
As would be evident to those skilled in the art, a sealant distribution line 102 supplies pressurized sealant to one or more dosers, of the industrial robot 100. In the embodiments illustrates herein, the industrial robot 100 has two dosers. In the exemplary embodiment of the present invention, a system (not illustrated) for distributing sealant upto the industrial robot 100 includes a sealant pump which pumps the pressurized sealant to the sealant distribution line 102, upon receiving a signal from a sealant controller. The sealant controller communicates with encoder to fill one or more dosers, as and when required.
Referring again to FIG. 1, the conventional sealant dispensing system 10 communicates the pressurized sealant from the sealant distribution line 102 and enables dispensing of the sealant on the work piece. The conventional sealant dispensing system 10 may be associated with an industrial robot, such as the industrial robot 100, for typical applications. The industrial robot 100 includes a forearm 104, a first wrist member 106 rotatably joined to the forearm 104, and a second wrist member 108 rotatably joined to the first wrist member 106. The second wrist member 108 may be rotatably connected to an aft portion 110 resting on the ground surface (not shown). The sealant distribution line 102 is supported on the aft portion 110 and regulating valves (not numbered) may be provided to selectively stop and start flow of the sealant through the sealant distribution line 102, for example during maintenance thereof. In an embodiment of the present invention, two sealant distribution lines such as a sealant distribution line 102a and a sealant distribution line 102b may be present and each of the two sealant distribution lines 102a, 102b may be supported on the aft portion 110 of the industrial robot 100.
As shown in Fig. 1, the sealant distribution line 102a of the sealant distribution system 10 is connected to a first doser assembly 112, carried by the first wrist member 106, to fill the sealant therein, through a first encoder (not numbered). The first encoder may be a ball-type encoder. A first proportional valve (not numbered) determines speed and volume of the sealant to be dispensed from the first doser assembly 112. An air-cable 14

(shown in dotted line in FIG. 1) travels along the aft portion 110 and is connected to the first proportional valve, to regulate the operation thereof. A second part 16 of the sealant distribution line 102a (also referred to as "sealant hose 16 of the sealant distribution line 102a") carries the sealant dispensed from the first doser assembly 112 to a sealant gun 18. Further, a second part 20 of the air-cable 14, coming from a first pair of solenoid members of a first terminal box; regulates final dispensing from a sealant gun 18.
The air-cable 14 traveling along the aft portion 110, and the first wrist member 106, and is connected to the second proportional valve, to regulate operation thereof. A second part 52 of the sealant distribution line 102b (also referred to as a "sealant hose 52" of the sealant distribution line 102b) carries the sealant dispensed from the second doser assembly 202. Further, a second part 56 of the air-cable 14 coming from a second pair of solenoid members of a second terminal box; regulates the final dispensing from the sealant gun 54 of the second doser assembly 202. The sealant dispensing system 200 includes a second doser assembly 202 (hereinafter also referred to as 'doser assembly 202') but unlike in the conventional system, the doser assembly 202 is not carried by the forearm 104. The sealant dispensing system 200 further includes a doser assembly mounting 204 connected to the first wrist member 106 (best shown in FIG. 1). The doser assembly mounting 204 is configured to carry the doser assembly 202. Therefore, the doser assembly 202 is mounted on the first wrist member 106.
Particularly, the doser assembly mounting 204 includes a gyro-shaped tennis bracket 206 encircling the first wrist member 106 and a winged-bracket projection member 208, and an adapter 209 connected to winged-bracket projection member 208. The adapter 209 is configured to carry the doser assembly 202. The winged-bracket projection member 208 is connected to the gyro-shaped tennis bracket 206 and is configured to allow at least one sealant hose to pass therethrough. Particularly, the winged-bracket projection member 208 includes one or more holes 210 to allow one ore more pipes to pass therethtough. In the given embodiment of the present invention, one or more holes are configured to allow the sealant hose 16 of the sealant distribution line 102a, coming from the first assembly 12 to pass therethrough and extend upto a distributer block 400. Further, the one or more holes may also be configured to allow the sealant hose 52 of the sealant distribution line

102b coming from the second doser assembly 50 to pass therethrough and extend up to the distributer block 400.
The distributer block 400 is carried by the forearm 104, In the disclosed embodiment, the distributer block 400 is removably attached to the forearm 104 and includes a plurality of hollow passages 402. Each hollow passage of the plurality of hollow passages includes a first end portion and an opposite end portion as a first opening and an opposite opening of the passage. The first end portion of the hollow passage is connected to the sealant hose 52. Likewise, a first end portion of any other hollow passage may be connected to the sealant hose 16. At least one sealant hose, such as the sealant hose 52 of the sealant distribution line 102b coming from the second doser assembly 50 upto the distributer block 400 may be provided with a permanent piping. Further, the sealant hose 16 of the sealant distribution line 102a coming from the first doser assembly 12 upto the distributer block 400 are also provided with a permanent piping. Furthermore, the second part 56 & 20 of the air-cable 14 are provided within a permanent piping, between the winged-bracket projection member 208 and the distributer block 400. In an embodiment of the present invention, an end portion of permanent piping forms a rotating joint with the distributer block 400.
The sealant dispensing system 200 furthermore includes at least one sealant distributer hose. The at least one sealant distributer hose is connected to the distributor block 400 and the sealant guns. In the disclosed embodiment of the present invention, the sealant dispensing system 200 includes two sealant distributer hoses namely, a first sealant distributer hose 404 and a second sealant distributer hose 406. The first sealant distributer hose 404 is connected to the distributer block 400 to transport the sealant to the sealant gun 18. Particularly The first sealant distributer hose 404 is connected to the distributer block 400 to transport the sealant carried up to the distributor block 400 by the sealant hose 52 from the doser assembly 50, to the sealant gun 18.
Likewise, the second sealant distributer hose 406 is connected to the distributer block 400 to transport the sealant to the sealant gun 54. Particularly, the second sealant distributer hose 406 is connected to the distributer block 400 to transport the sealant carried up to the

distributor block 400 by the sealant hose 16 from the doser assembly 12, to the sealant gun 54. The second part 20 of the air-cable 14 may also pass through the distributer block 400. Furthermore, a sealant gun adapter 408 may be carried by the forearm 104. The adapter may be configured to carry the sealant gun 54. The sealant gun adapter enables the sealant gun 54 to remain in same position with respect to the forearm, even after repositioning of the second doser assembly 50.
The foregoing description provides specific embodiments of the present invention. It should be appreciated that these embodiment are described for purpose of illustration only, and that numerous other alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.