FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"A JERK-FREE CHECK ARM FOR THE DOOR OF A MOTOR VEHICLE"
MAHINDRA & MAHINDRA LIMITED
AN INDIAN COMPANY,
R&D CENTER, AUTOMOTIVE SECTOR,
89, M.I.D.C., SATPUR,
NASHIK-422 007,
MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:-
The present invention is related to the automotive body systems. More particularly the present invention is related to the check arm of the vehicle door wherein the said check arm does not provide the jerk during opening operation of the door of the vehicle.
BACK GROUND OF INVENTION:-
The check arm in vehicle door closing system is known as shown in the figure 1 of accompanying drawing. It is observed that the one end of check arm fixed to the body of vehicle is having two pair grooves (G )opposite side and at distant a check house (HD) fitted to the door provided with a spring biased ball (CB)in the groove, while opening door balls enters the far end grooves (G)on check arm and while closing door the balls enter the near end grooves. It is observed that the door closing and opening is not smooth requires more effort. Check arm what we are currently using which is shown above have detent or grove (check position) which is "V" or "U" shaped. Due to this "V" shaped groove(G) while opening the door, the door oscillates about that grove when it comes to that position. That is during door opening, when the check ball comes to that grove portion it over travels that grove and then comes to the center of grove and depending upon the force of opening the door it again over travels the grove in the other side and settles down. This oscillation of the door over that grove while opening creates discomfort among the customer. The failure of spring or worn out of grooves makes totally non functioning door. The present invention is a solution to the such type of check arm.
OBJECTIVES OF THE INVENTION:-
It is an object of invention to provide a check arm to vehicle door system for effort less smooth opening and closing of door.

It is another object of invention to provided non mechanical means to check arm for control of opening closing so as to avoid wear and tear of check arm part.
It is another object of invention to provide check arm with magnet means for control of opening and closing of vehicle door.
It is another object of invention to provide a check arm for opening and closing of vehicle door free from oscillation.
It is also another object of invention to provide a check arm having improved ergonomic of the operation.
BRIEF DESCRIPTION OF THE FIGURES:-
Figure 1 shows the conventional check arm system available in the prior art.
Figure 2 shows exploded view check arm with check house in accordance with the present invention.
Figure 3 shows another view of check arm with its mounting means to the vehicle body.
Figure 4 shows the exploded view of check housing of the check arm in accordance with the present invention.
DESCRIPTION OF THE PRESENT INVENTION:-
Referring to figure 1 check arm what we are currently using which is shown above have detent or groove (G) (check position) which is "V" or "U" shaped. Due to this "V" shaped grove while opening the door, the door oscillates about that grove when it comes to that position. That is during door opening, when the check ball comes to that groove (G) portion it over travels that grove and then comes to the center of grove and depending upon the force of opening

the door it again over travels the grove in the other side and settles down. This oscillation of the door over that grove while opening creates discomfort among the customer. Some other problems related to the current system is that, if the spring in the system fails then the whole system fails. The design of check arm and the check house is also complex in the current system. Also the mechanism involved in the current system is also complex.
To avoid that oscillatory motion of door while opening, in the present invention magnetic principle is used. The model consists of spherical magnet in the check house and plastic check arm. Referring to figures 2 to 4, a jerk-free check arm 1 for the door of a motor vehicle comprises of a pair of spherical magnet 2 at distance freely rotating in a holder one in top and other at bottom placed in a the check house 3 fitted to the vehicle door; a check arm 1 made of plastic, fixed to the body of vehicle, provided with a iron sheet form 4 at top and bottom by clamping over the check arm 1 at a distance location, to the extent door of vehicle to be opened, from the body of vehicle ; the arrangement is such that when the door opens, the spherical magnet 2 in the check house 3 slides over the check arm and due to the magnetic attractive force of the iron to the spherical magnet, the spherical magnet 2 stops over the iron sheet form 4 on the check arm 1 and the door stops in that position without having any oscillatory motion.
Ceramic permanent magnets can be used. Cobalt based magnet can also be used but it is costlier compared to ceramic permanent magnets. Ferrite based permanent magnet can also be used. But the disadvantage is that it is very fragile and expensive tooling is required to manufacture it. Check arm can be made up of Noryl material. It can also be made up of nylon material. Body mounting bracket can be made up of steel. The check house can be made up of steel.

WE CLAIM:-
1. A jerk-free check arm for the door of a motor vehicle comprises of a pair of spherical magnet at distance freely rotating in a holder one in top and other at bottom placed in a the check house fitted to the vehicle door; a check arm made of plastic, fixed to the body of vehicle, provided with a iron sheet at top and bottom by clamping over the check arm at a distance, to the extent door of vehicle to be opened, from the body of vehicle ; the arrangement is such that when the door opens, the spherical magnet in the check house slides over the check arm and due to the magnetic attractive force of the iron to the spherical magnet, the spherical magnet stops over the iron sleeve on the check arm and the door stops in that position without having any oscillatory motion.
2. A jerk-free check arm for the door as claimed in claim 1 wherein the said holder is cup like ring with central opening for protruding said spherical ball there through fixed to the said check housing.
3. A jerk-free check arm for the door as claimed in 1 and 2 wherein the said check arm is mounted to the vehicle body with a U-type bracket.
4. A jerk-free check arm for the door as claimed in claims 1 to 3 wherein the said magnate is of Ceramic permanent magnets, or Cobalt based magnet or Ferrite based permanent magnet.

5. A jerk-free check arm for the door ac claimed in claims 1 to 4 wherein the said check arm made up of Noryl material or nylon material.