FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
PROVISIONAL / COMPLETE SPECIFICATION (See section 10 and rule 13)

1. TITLE OF THE INVENTION 2. Head Lamp Levelling System for Automotive Vehicles.
2. APPLICANT(a) NAME : MAHINDRA & MAHINDRA LTD(b) NATIONALITY : An Indian Company registered under the Companies Act, 1956(c) ADDRESS : R&D Centre, Auto sector, 89, M.I.D.C, Satpur, Nashik- 422007. Maharashtra State. India
3. PREAMBLE TO THE DESCRIPTION
PROVISIONALThe following specification describes the invention . COMPLETEThe following specification particularly describes the invention and the manner in which it is to be performed.


Technical Field
The invention is related to the field of headlamp levelling system used in automobile vehicles. More particularly it is related to manual headlamp levelling mechanism by which vertically tiltable reflectors are moved to and fro to aim the direction of light beam within the limited space of lamp body.
Background and Prior Art
The levelling mechanism is a mechanism for changing the direction of the light beam in response to the load on the vehicle. All the headlamps of automotive vehicles are with tiltable reflector resting on lamp body with rotating mechanism. By adjusting this headlamp reflector, the direction of the light beam can be aimed. Initial headlamp aiming is done with this mechanism at vehicle production line.
Headlamp levelling (space adjustment) done by the electric motor backed mechanism is well known in the prior art. One end of the motor is attached to the head lamp reflector and other end is connected to electrical switch. When we change the position of the electrical switch, motor rotates accordingly causing headlamp reflectors to move in to or fro direction as desired.
United States Patent No. US 4881152 discloses a headlight device comprising a lamp body having a recess which opens forward, a lens covering the forward opening of the lamp body and a reflective mirror tiltably supported in the lamp body through one rotatable support portion and two space adjusting portions. Each space adjusting portion


consists of a nut member supported on the reflective mirror, an adjusting rod rotatably supported on the lamp body and having a screw thread portion for screw-threadingly engaging with the nut member, a gear unit consisting of two intermeshing bevel gears with one of which being connected to the rear end of the adjusting rod, and an actuating rod with the front end of which being located near to the front end of a side surface of the lamp body and the rear end of which being located near to the front end of a side surface of the lamp body and the rear end of which being connected to the other bevel gear of the gear unit.
Japanese patent no. JP4259702A, German patent No. DE 4204097 Al and UK patent no. GB 2253900 describes headlamp levelling mechanism comprising a levelling member linearly moved back and forth by a levelling motor via drive gear means for tilting the reflector so as to level the beam. A printed circuit board is provided which has formed thereon a conductive pattern connected in circuit with the levelling motor. A contact gear rotatably mounted on a main shaft rigidly mounted to the printed circuit board carries contact means for revolving the same in sliding engagement with the conductive pattern so that the levelling motor may be set out of rotation when the beam is levelled. The contact gear is driven from the drive gear means via speed reduction gear means. Characteristically, for the ease of assemblage and for the accurate interengagement of the contact gear and the speed reduction gear means, the speed reduction gear means is rotatably mounted to a bearing member which is supported by the main shaft.


United States patent no. US 6814469B2 discloses a rotating reflector with an adjustment mechanism. Reflector assembly is rotatably attached to the housing within the interior compartment of the housing and an adjustment mechanism that is operable from the external surface of the housing to cause movement of the reflector assembly relative to the housing into a continuous range of operating positions. The adjustment mechanism comprises more than one screw assemblies configured to the reflector assembly relative to the housing.
European patent no. EP 0472280 describes a headlamp aiming and leveling apparatus for use with a headlamp assembly having a mounting arrangement in the form of a pair of adjacent, spaced slots with an open area there between, the slots receiving the aiming and leveling apparatus and the open area permitting viewing of the aiming and leveling apparatus when mounted to the slots. The aiming and leveling apparatus comprises a level member having a viewable indicator. An adjustment member is operatively coupled to the level member for adjusting the position thereof and correspondingly adjusting the indication provided by the indicator. A mounting device mounts the aiming and leveling apparatus in the slot with the level. member disposed in the open area.
United States patent no. US 4843523 discloses a headlight device including movable member connected to a stationary supporting member at spaced apart three points, at two of said three points said movable member being connected respectively to the stationary supporting member through aiming mechanism which enable to


change the space between the supporting member and the movable member respectively. At least one of the aiming mechanism comprises an adjusting rod and a gear unit, and the gear unit includes a casing mounted on the supporting member, a worm gear, a worm wheel meshing with the worm gear, a pinion gear co-axial with the worm gear, a driving gear meshing with the pinion gear, with the axis of the driving gear being arranged orthogonal to the axis of the worm wheel, and an actuating rod connected to the driving gear and extending through the casing. The adjusting rod has one end being rotatably connected to the movable member and screw threads being formed in the intermediate portion for engaging with the threaded bore in the worm wheel of the gear unit.
United States patent no. US 5707134 disclose a vehicular lamp including a reflector, a member of tiltably supporting the reflector and an aiming screw for driving the reflector to tilt by rotating. The aiming screw serves as a shaft member linking to the reflector supporting member by a so-called rotation pair, while linking to the reflector by so-called screw pair. The reflector is formed with an aiming screw stopper which comes into abutment against a tip end part of the aiming screw when the reflector tilts up to a predetermined angle position thereby to inhibit the reflector to tilt beyond the predetermined angle.
Korean patent application no. KR 2005/0012877 discloses a head lamp provided to achieve improved use convenience by easily adjusting the height and angle of a magnifying lens unit and a lamp unit. A head lamp comprises a height adjustment unit, a lamp unit, a


rotating unit and a magnifying lens unit. The height adjustment unit includes a vertical coupling element having a vertical screw thread, a horizontal coupling element screw-coupled to the vertical screw thread such that the horizontal coupling element is slidable in a vertical direction, an elastic fixing element for fixing the vertical position of the horizontal coupling element, and a rotatable screw thread accommodating hole arranged at an end of the horizontal coupling element. The lamp unit is formed into a cylinder and has one side with a lighting member and the other side with a rotatable screw thread accommodating hole. The rotating unit is L-shaped, and has both ends with rotatable screw threads. The rotating unit is screw-coupled to the rotatable screw thread accommodating holes of the height adjustment unit and the lamp unit such that the rotating unit adjusts the vertical position and front and rear angles of the lamp unit.
United States patent no. US 6481879B1 described a headlamp with movable reflector which includes lamp body, a reflector and an aiming mechanism interposed between lamp body and the reflector for tiltably supporting the reflector with respect to lamp body. The reflector tilts by rotational movement of the aiming screw which is rotatably supported in a screw insertion hole formed on the lamp body. The swinging strips engage with an engaging groove formed on the aiming screw to prevent the aiming screw from being detached from the lamp body. The aiming screw includes a rotatably supported portion formed of resin, a make screw portion, and a gear portion behind the rotatably supported portion. Further the rotatably


supported portion is unitarily formed with a skin type resilient watertight rib in pressurized contact and sliding contact with the rod surface of the backward extension of the tubular portion to ensure the resilient support of the aiming screw in the forward and backward direction and to ensure watertightness at the rotatably supported portion.
Deficiencies of Prior Art
1. In the available devices the space adjusting portion projects by a large amount in the rear direction, thus, there is a problem that the size of the headlight device in the front and rear direction increases.
2. The headlamp levelling mechanisms known in the art activate only when ignition is switched ON as they are costlier too.
3. None of the headlamp levelling mechanisms known in art is independent of motor and electric power source (battery)
4. None of the headlamp levelling mechanisms in public domain uses sliding mechanism for aiming the beam of head light.
Object of the Present Invention
The main objects of the present invention are-
1. To overcome the shortcomings in the prior art headlamp levelling/aiming mechanisms.
2. To provide headlamp device for use in an automobile and of the type vehicles with manually operated novel and improved


mechanism for headlamp levelling independent of electric power source (battery). 3. To effectively use the space of an engine compartment of the automotive vehicle.
Advantages of the Present Invention
1. The present invention makes the headlamp levelling mechanism simple and easy to operate.
2. It is low cost and requires less space within the engine compartment.
3. The levelling mechanism meets the light distribution characteristics and improves workability during levelling operation of the lamp.
4. Easy to change predetermined angle position of the reflectors.
5. It can be operated even if the ignition is OFF.
Description of the invention
Generally the vehicular lamps such as headlamps, fog lamps or the like are provided with levelling mechanism for adjusting the illumination angle of reflected light beam. This levelling mechanism is also called as aiming or space adjustment mechanism. The levelling mechanisms in public domain are battery operated and provided with a motor and a levelling/aiming screw for initial adjustment. The present invention has been made in line with existing electrical systems wherein the electrical system is replaced with the mechanical actuator consisting of sliding mechanism, spring and gear arrangement.


Description of figures
Figure 1 shows the sectional view of the headlamp along the central
line without headlamp levelling mechanism.
Figure 2 presents the sectional view of headlamp along with the
headlamp levelling mechanism as discussed in the present invention.
Figure 3 shows the enlarged sectional view and two dimensional view
of the actuator in headlamp levelling mechanism of the present
invention.
Figure 4 shows the headlamp levelling mechanism operating switch as
described in the present invention.
Detailed description of embodiment
The head lamp levelling system disclosed in the present invention consists of head lamp (1), tiltable reflectors (2), actuator called levelling mechanism (3), levelling cables (4) and operating switch (5). The reflector of the lamp is fixed with a screw (17) on lamp base (18) which is a tiltable. The reflector hinge along with the headlamp base is shown by no. (20), this reflector is with a reflective film of aluminium coating on internal surface. For proper aiming/levelling purpose of the head lamp, the tiltable reflectors can be moved in 6, 7 and 8 positions as shown in Fig. 1. The bulb (21) is inserted from the rear side of the glass portion through the bore and fixed against spring tension. Lower portion (22) of the lamp body protects the head lamp assembly.
Referring to the figure 3, the main components of actuator/levelling mechanism (3) are a moving stem/shaft (9) with ball type knob (10) at its one end, slider (11), a tension spring (12), initial


adjustment nut (13), locking nut (14) and all these components are arranged in a housing (15) as shown in Fig. 3. The shaft (9) of the actuator/levelling mechanism (3) is rigidly attached to the slider (11) and moves in to and fro direction against the spring tension. Spring tension is adjusted by the adjusting nut (13) and for locking of it locking nut (14) is provided. One end of the slider (11) is having a hook type structure (15) for attaching the levelling cables (4).
One end of the actuator (3) that is the knob (10) rests on the tiltable reflector (2) and rigidly connected to it, through the bracket plug (16) given for its fitment, to allow the movement of the reflector in forward and/or backward direction as desired within the space of head lamp body. The other end of the actuator (3) is connected to the one end of levelling cable (4) through the hook (15). The other end of levelling cable (4) is attached to the head lamp levelling switch (5) which is generally placed on the dashboard or it can be placed any where as per the convenience of the driver. The headlamp levelling switch is of mechanical type with gear arrangement (19) which will avoid the slippage of the slider. The gear arrangement (19) converts the rotary movement of the switch into linear movement of the slider and consequently that of the reflectors through the levelling cables.
Figure 2 explains the new mechanical headlamp levelling mechanism (actuator) attached to the headlamp body. (1) is the same head lamp body with ball knob (10) and moving stem/shaft (9). This mechanism /actuator have to be attached to the headlamp body from its rear side. The initial adjustment nut (13) is provided to the other


end of the mechanism to do the initial settings and a slot / hook (15) is provided to fix levelling cable from head lamp to switch. When the switch is operated, the levelling cables will move the reflectors vertically to direct the beam of head light.
There are two levelling mechanisms/actuators (3) for two head lamps connected through two cables to a single levelling switch. The initial vertical and horizontal levelling of the headlamp is done at production stage with screw driver. The secondary levelling by the mechanism disclosed herein is done by keeping the existing horizontal position as a reference.
When the levelling switch (5) is rotated in anti-clockwise direction, both the levelling cables (4) are pulled which consequently move the slider (11) outward from the actuator (3). The slider and moving stem/shaft are rigidly connected to each other. The outward movement of the slider (11) is transferred to the reflectors (2) through the shaft (9) and thus, the reflectors can be levelled in 6, 7 or 8 positions as desired for proper aiming of the light beam within the space of head lamp body. When the levelling switch (5) is rotated in clockwise direction, both the levelling cables (4) are released which consequently move the slider (11) back to its original position because of spring tension. The rearward movement of the slider (11) is transferred to the reflectors (2) through the shaft (9) and thus, the reflectors can be levelled in its original position as desired within the space of head lamp body. Such two mechanical actuators are required for one vehicle to fix it on the left & right head lamp body. Along with it two cables are


attached which are connected to the mechanical switch on the compartment.
Thus, the present invention replaces the prior art head lamp levelling concepts and meets its objectives. The mechanical system disclosed herein is like it has a stator with a moving stem which moves to and fro against spring tension. It should be understood that the present invention is not to be limited by the exact details of the illustrated embodiments. However, it is to be taken as the preferred example of the invention and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of below mentioned claims. Also, the terminologies used herein are for the purpose of description and should not be regarded as limiting.


claim
1. Headlamp levelling system for automotive vehicles comprising;
an actuator (3) with its one end connected to tiltably supporting
reflector (2) and other end connected to levelling cables (4);
levelling cables (4) and levelling switch (5) with gear
arrangement (19); a reflector (2) rotatably attached to the
headlamp housing (15) within the interior compartment and
sliding type levelling mechanism (3) that is operable externally
from the dashboard of the vehicle to cause the movement of the
reflector without the use of battery power or even if the ignition
switch OFF; an actuator (3) provided with spring configured to
move the reflectors (2) in up-down directions as desired; an
actuator (3) provided with initial adjustment nut (13) and locking
nut (14); levelling switch (5) of mechanical type with gear
arrangement (19) as disclosed herein and which will avoid the
slippage of the slider (11) and convert the rotary movement of
the switch (5) into linear movement of the slider (11) and
consequently that of the reflectors through the levelling cables
(4).
2. Headlamp levelling system as claimed in 1 wherein the said
levelling mechanism (3) is attached to the rear side surface of the
reflector (2) forming the section of the said reflector (2).


3. Headlamp levelling system as claimed in claim 1 and 2 wherein, the said sliding type levelling mechanism (3) tilts the reflector (2) in the up-down direction; the levelling cable (4) can be replaced with mechanical linkage or by combination of thereof.
4. Headlamp levelling system for automotive vehicles as claimed in claim 3 wherein

(a) apart from headlamp levelling it can be used for levelling fog lamp, tail lamp and like wise on any type of motor vehicle.
(b) the sliding type levelling mechanism (3) can be used to aim the reflectors in any direction.

5. Headlamp levelling system for automotive vehicles as claimed in claim 4 wherein the material of construction is not limited to steel or fibre reinforced plastic or aluminium die casting, however it can be made of any suitable and durable material fulfilling the required strength and purpose.
6. Headlamp levelling system for automotive vehicles substantially as herein above described in the specification with reference to the accompanying drawing.




Abstract
The present invention is related to mechanical headlamp levelling mechanism by which vertically tiltable reflectors, with respect to vehicle body, of the headlamp are moved in up-down direction to aim the direction of light beam within the limited space of lamp body. The levelling mechanism has been made in line with existing electrical systems wherein the aiming motor is replaced with the mechanical actuator comprising of moving stem/shaft, sliding mechanism, spring, levelling cables and gear arrangement.
The disclosed mechanism makes the lamp levelling simple and easy to operate and can be operated even if the ignition is OFF. It is a low cost technology and requires less space within the engine compartment. The levelling mechanism meets the light distribution characteristics and improves workability during levelling operation of the lamp.