FORM 2
THE PATENTS ACT 1970
(39 of 1970)
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See Section 10; rule 13)
TITLE OF INVENTION
Improved Pantograph Wiper Mechanism
APPLICANTS
TATA MOTORS LIMITED,
an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Srinivasa Raju Gavarraju & Ashfaque Ahmed Ansari
both Indian Nationals
of TATA MOTORS LIMITED,an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
This invention relates to the wiping mechanism used in vehicles and more particularly to string type pantograph wiping mechanism.
BACKGROUND OF INVENTION
Windshield wiping mechanism is generally used in vehicles to wipe the windshield glass to make it free from water, dirt and dust. Conventional windshield wiper mechanism comprises of motor driven spindle, arm and blade. Wherein said arm is connected to the said spindle and blade, the rotary motion of the motor is converted to oscillatory motion of the blade through arm.
The drawback associated with said conventional windshield wiping mechanism is that, it is not possible to reach the desired parking and up positions with this type of mechanism.
US2336007 teaches pantograph wiping mechanisms used in aircraft, comprises of motor driven spindle, arm, link structure and blade. Wherein said arm is connected to the said spindle and blade, the rotary motion of the motor is converted to oscillatory motion of the blade through arm. Said link structure assist in achieving the pantograph wiping.
The drawback associated with said prior art is that, it requires additional link mechanism and the mounting of which obstructs the field of vision. In addition to this, this also affects aesthetic appeal.
In order to overcome the above said drawbacks, this invention is devised.


OBJECTS OF INVENTION
The main object of this invention is to provide an improved pantograph wiper mechanism, which will not affect the field of vision and contribute for good aesthetics.
Yet another object of this invention is to provide an improved pantograph wiper mechanism which is flexible and which can reach to the desired parking and up positions.
Yet another object of this invention is to provide an improved pantograph wiper mechanism, which is simple in construction and cost effective.
STATEMENT OF INVENTION
Improved pantograph wiper mechanism comprises of spindle, arm, flexible string, spring and blade, wherein said arm is having a head portion, a body portion and a hook portion, said head portion is provided with a provision to hold in a spindle, and is hinged to the said body portion, said body portion and hook portions are joined together through said spring, one end of said arm is connected to spindle and hooked end is connected to said blade, one end of said flexible string is connected to the said spindle at its periphery and other end is connected to the said hook portion of said arm.
BRIEF DESCRIPTION OF INVENTION
Improved pantograph wiper mechanism in accordance with this invention basically comprises of spindle, arm, flexible string, spring and blade. Said arm is having a head portion, a body portion and a hook portion, said head portion is provided with a provision to hold in a spindle, and is hinged to the said body portion. Said body portion and hook portions are joined together by fastening


through said spring. One end of said arm is connected to spindle and hooked end is connected to said blade. One end of said flexible string is connected to the said spindle at its periphery and other end is connected to the base portion of said hook portion of said arm. Said flexible string is made to pass along the said body portion of said arm. Said flexible string is connected to said spindle at left side of the centre line of the arm when it is in up position based on the requirement of desired wiping area. Said hooking portion of said arm is provided with provision to hold the said blade. Said arm is provided with coil spring to apply pressure on said blade, one end of said coil spring is connected to the said head portion and other end is connected to the said body portion.
Said body portion of said arm is provided with stopper to prevent the movement of the wiper blade beyond the desired wiping area.
During operation the spindle receives oscillatory motion from motor, said oscillatory motion is transferred to the said wiper blade through said arm. Because of which the said blade moves between parking and up positions. During movement of said blade from parking to up position, the said flexible string pulls the said hook portion of arm, which in turn tilts the said blade to the desired wiping area. During movement of said blade from up to parking position the said spring provided between body portion and hook portion of said arm assist in putting the said blade in original parking position.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 shows line diagram of the improved pantograph wiper mechanism in
accordance with this invention.
Figure 2 shows improved pantograph wiper mechanism fitted on vehicle.
Figure 3 shows the exploded view of the improved pantograph wiper
mechanism.


DETAILED DESCRIPTION OF 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,
Referring to figure 1, figure 2 and figure 3,
Improved pantograph wiper mechanism in accordance with this invention basically comprises of spindle (8), arm (1), flexible string (6), spring (5) and blade (9). Said arm is having a head portion (la), a body portion (lb) and a hook portion (lc), said head portion (la) is provided with a provision (2) to hold in a spindle (8), and is hinged to the said body portion (lb). Said body portion (lb) and hook portions (lc) are joined together by fastening (4) through said spring (5). One end of said arm (1) is connected to spindle (8) and hooked end (lc) is connected to said blade (9). One end of said flexible string (6) is connected to the said spindle (8) at its periphery (15) and the other end is fixed in a slot (3) provided in the base portion of said hook portion (lc) of said arm. The body portion of the arm (lb) has provision (7) for routing the flexible string (6) through the said body portion (lb) of said arm. Said flexible string (6) is connected to said spindle (8) at left side of the centre line of the arm when it is in up position based on the requirement of desired wiping area. Said hooking portion of said arm (lc) is provided with provision (10) to hold the said blade (9). Said arm is provided with coil spring (11) to apply pressure on said blade (9), one end of said coil spring (11) is connected to the said head portion (la) and other end is connected to the said body portion (lb).
Said body portion of said arm (1) is provided with stopper (12) to prevent the movement of the wiper blade beyond the desired wiping area.


Said body portion (lb) of the said arm (1) has groove (13) to hold one end of the spring (5) and said hook portion (lc) of the said arm (1) has groove (14) to hold other end of the spring (5).
During operation the spindle (8) receives oscillatory motion from motor, said oscillatory motion is transferred to the said wiper blade (9) through said arm (1). Because of which the said blade (9) moves between parking position (A) and up position (B) on windshield (C). During movement of said blade (9) from parking to up positions, the said flexible string (6) pulls the said hook portion (lc) of arm (1), which in turn tilts the said blade (9) by an angle (a) to the desired wiping area. During movement of said blade (9) from up position (B) to parking position (A) the said spring (5) provided between body portion (lb) and hook portion (lc) of said arm (1) assist in putting the said blade (9) in original parking position (A).
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous 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.


WE CLAIM
1. Improved pantograph wiper mechanism comprising of spindle, arm, flexible string, spring and blade, wherein said arm is having a head portion, a body portion and a hook portion, said head portion is provided with a provision to hold in a spindle, and is hinged to the said body portion, said body portion and hook portions are joined together through said spring, one end of said arm is connected to spindle and hooked end is connected to said blade, one end of said flexible string is connected to the said spindle at its periphery and other end is connected to the said hook portion of said arm.
2. Improved pantograph wiper mechanism as claimed in claim 1 wherein said flexible string is connected to said spindle at left side of the centre line of the arm when it is in up position based on the requirement of desired wiping area.
3. Improved pantograph wiper mechanism as claimed in claims 1 and 2 wherein said body portion and hook portion are joined together by fastening through said spring.
4. Improved pantograph wiper mechanism as claimed in claims 1 to 3 wherein said flexible string is made to pass along the said body portion of said arm.
5. Improved pantograph wiper mechanism as claimed in claims 1 to 4 wherein said arm is further provided with coil spring to apply pressure on said blade, one end of said coil spring is connected to the said head portion and other end is connected to the said body portion.
6. Improved pantograph wiper mechanism as claimed in claims 1 to 5 wherein said body portion of said arm is further provided with stopper to prevent the movement of the wiper blade beyond the desired wiping area.
7. Improved pantograph wiper mechanism as claimed in claims 1 to 6 wherein one end of said flexible string is connected to the said spindle at


its periphery and other end is connected to the base portion of said hook
portion of said arm.
Improved pantograph wiper mechanism as claimed in claims 1 to 7
wherein said body portion and hook portions are joined together through
a torsion spring.
Improved pantograph wiper mechanism as claimed in claims 1 to 8
wherein said body portion of the said arm has groove to hold one end of
the spring. Said hook portion of the said arm also has groove to hold
other end of the spring.
Improved pantograph wiper mechanism and process of manufacturing
improved wiper mechanism substantially as herein described with
reference to accompanying drawings.




ABSTRACT
Improved Pantograph Wiper Mechanism
This invention relates to the wiping mechanism used in vehicles and more particularly to string type pantograph wiping mechanism. Improved pantograph wiper mechanism in accordance with this invention basically comprises of spindle, arm, flexible string, spring and blade, wherein said arm is having a head portion, a body portion and a hook portion, said head portion is provided with a provision to hold in a spindle, and is hinged to the said body portion, said body portion and hook portions are joined together through said spring, one end of said arm is connected to spindle and hooked end is connected to said blade, one end of said flexible string is connected to the said spindle at its periphery and other end is connected to the said hook portion of said arm. Fig. 1