Claims: WE CLAIM:
1. An electronic steering column lock (ESCL) assembly with a backup mechanical stopper for locking and unlocking the steering column of automotive vehicles, the ESCL assembly (10) comprising:
a lower housing (4) having a drive motor (5), a worm cluster gear (6), an idler gear (7) and a lift gear (8) accommodated therein, wherein
the drive motor (5) drives the worm cluster gear (6),
the worm cluster gear (6) meshes with the idler gear (7), and
the idler gear (7) drives the lift gear (8) in response to the motion provided by the worn cluster gear (6), wherein the lift gear (8) accommodates a locking mechanism with a lock bolt (9),
a magnet carrier (3) snapped onto the lift gear (7), the magnet carrier having a magnet (3a) embedded thereon, wherein when the lift gear (8) rotates the magnet carrier (3) along therewith, the lock bolt (9) moves in up and down direction to perform locking and unlocking of the steering column;
a plurality of electronic stoppers (1) placed at locking and unlocking ends to monitor the position of the lock bolt (9) through the magnet (3a) embedded in the magnet carrier (3); and
a gearbox cover (2) fitted on the lower housing (4) to blanket the ESL assembly (10), the gearbox cover (2) having a secondary stopper (2a) incorporated therein, wherein the secondary stopper (2a) controls the rotation of the magnet carrier (3) within the range of the electronic stoppers (1).
2. The system (100) as claimed in claim 1, wherein the lock bolt (9) translates the motion from the rotation of the lift gear (8) in the up and down direction.
3. The ESCL assembly (10) as claimed in claim 1, wherein the electronic stoppers (1) are Hall Effect sensors.
4. The ESCL assembly (10) as claimed in claim 1, wherein the electronic stoppers (1) triggers and gives a signal to a controller when the magnet carrier (3) rotates and the magnet (3a) comes in the range of the electronic stoppers (1).
5. The ESCL assembly (10) as claimed in claim 1, wherein the secondary stopper (2a) includes a first stopping face (2ai) and a second stopping face (2aii).
6. The ESCL assembly (10) as claimed in claim 4, wherein the first stopping face (2ai) and the second stopping face (2aii) makes maximum contact with the magnet carrier (3) to relieve the stress during impact.
7. The ESCL assembly (10) as claimed in claim 1, wherein the magnet carrier (3) stops within the range of the electronic stoppers (1) by hitting the first stopping face (2ai) and second stopping faces (2aii) in locking and unlocking respectively during more rotation of the magnet carrier (3) due to high inertia.
Dated this on 11th day of June 2021
Prafulla Wange
(Agent for the applicant)
(IN/PA-2058)

, Description:BACKUP MECHANICAL STOPPER WITH ROTATION CONTROL IN ELECTRONIC STEERING COLUMN LOCK
FIELD OF THE INVENTION:
The present invention relates to the field of automotive vehicles, and more particularly, the present invention relates to the Electronic Steering Column Lock (ESCL) for locking and unlocking a steering column of a motor vehicle.
BACKGROUND OF THE INVENTION:
A column lock used in an automotive vehicle usually comprises an electrical motor for controlling the movement of a bolt from a locking position to a rest position, in which the steering column is respectively blocked or unblocked, which means free in rotation.
An Electronic Steering Column Lock (ESCL) locks and unlocks the steering column as per requirements to achieve anti-theft in keyless cars. The ESCL assembly accurately controls and monitors the motion and the position of a lock bolt for locking and unlocking the steering column. In the present ESCL assembly, the motion of the lock bolt is controlled by a drive motor and a reduction gear train. Whereas the position is continuously checked by the Hall Effect sensors. The Hall Effect sensors are mounted on a PCB. The Hall Effect sensors are placed at the locking and unlocking position of the lock bolt. When a magnet carrier rotates from one position to another, the relative signal is given to the controller by the Hall Effect sensors. The ESCL assembly is designed in such a way to convert the rotation of the motor into linear travel of the lock bolt, thereby locking or unlocking the operation of the steering column. During the trials, it was observed that at very high input speeds the magnet carrier and, thereby, the lock bolt travels very fast, and in these rare cases it over travels the detection range of the Hall Effect sensor due to high moment of inertia. Thus, there is a need to stop the magnet carrier in these conditions before it leaves the detection range of the Hall Effect sensor.
Presently, Hall Effect sensors (to be referred as ‘electronic stoppers’ hereinafter) are used to stop the rotation of the magnet carrier in such a situation. If the magnet carrier rotates more than the permissible limit of the electronic stopper, due to excessive input speeds it will go out of reach of the electronic stoppers. Thus, the ESCL assembly stops functioning anymore as the controller is not able to detect the magnet carrier’s position. The prior documents are lacking properly designed secondary stoppers and had electronic or switch type stoppers. The failure in the electronic stoppers or switch type stoppers leads to function failure. In the case of the electronic stoppers, if the magnet carrier over travel due to excessive input speed and moment of inertia, the magnet carrier goes out of reach of the electronic stoppers, and the critical design is required to control and detect the magnet carrier’s position.
Accordingly, there exists a need to provide a mechanism for the electronic steering column lock (ESCL) assembly to restrict the magnet carrier’s rotation within the range in case the magnet carrier goes out of reach of the electronic stopper due to the magnet carrier’s over travel.
OBJECTS OF THE INVENTION:
An object of the present invention is to provide a mechanism for the Electronic Steering Column Lock (ESCL) assembly to achieve antitheft in keyless cars.
Another object of the present invention is to stop the magnet carrier of the ESCL assembly before it leaves the detection range of the Hall Effect sensor.
Still, another object of the present invention is to provide a mechanical stopper in a gearbox cover of the ESCL assembly for restricting the rotation of the magnetic carrier within range.
Yet another object of the present invention is to provide the mechanical stopper as a secondary stopper for the magnetic carrier after the electronic stopper for making the system full proof.

SUMMARY OF THE INVENTION:
Accordingly, the present invention provides an electronic steering column lock (ESCL) assembly with a backup mechanical stopper. The ESCL assembly with the backup mechanical stopper controls the rotation of the magnet carrier within the range of the electronic stoppers by restricting the rotation thereof and helps the electronic stoppers in position detection of the magnet carrier for the next stroke of ESCL.
The Electronic Steering Column Lock assembly comprising a lower housing, a magnet carrier, a plurality of electronic stoppers, and a gearbox cover. The lower housing provides facility to mount a drive motor, a worm cluster gear, an idler gear, and a lift gear. The drive motor drives the worm cluster gear. The worm cluster gear meshes with the idler gear which drives the lift gear in response thereto. The lift gear is snapped with the magnet carrier which rotates therewith. The magnet carrier is embedded with a magnet. The lift gear comprises a locking mechanism with a lock bolt. Whenever the lift gear rotates along with the magnet carrier, the lock bolt moves in an up and down direction to perform locking and unlocking of the steering column. The plurality of electronic stoppers are placed at the locking and unlocking ends to monitor the position of the lock bolt through the magnet.
The gearbox cover is fitted on the lower housing to cover the ESCL assembly. The gearbox cover has a secondary stopper with at least two stopping faces. The secondary stopper controls the rotation of the magnet carrier within the range of the electronic stoppers. When the magnet carrier rotates more due to high inertia, the secondary stopper controls the magnet carrier within the range of the electronic stoppers by hitting the first and second stopper faces in locking and unlocking respectively. This results in the tracking of the lock bolt position by the electronic stoppers accordingly.

BRIEF DESCRIPTION OF THE DRAWINGS:
The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows an isometric view of an electronic steering column lock (ESCL) assembly without a gearbox cover, in accordance with the present invention;
Figure 2 shows an auxiliary view of the gearbox cover, in accordance with the present invention;
Figure 3 shows a top view of the electronic steering column lock (ESCL) assembly with the gearbox cover, in accordance with the present invention;
Figure 4 shows a sectional view of the electronic steering column lock (ESCL) assembly, in accordance with the present invention;
Figure 5 shows a side view of the electronic steering column lock (ESCL) assembly, in accordance with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS:
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
The present invention provides the Electronic Steering Column Lock assembly for locking and unlocking the steering column for automotive vehicles. More particularly, the present invention provides the secondary stopper mechanism for Electronic Steering Column Lock assembly.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in a bracket in the following description.
Referring to Figure 1-5, there is shown an Electronic Steering Column Lock (hereinafter ‘ESCL’) assembly (10) comprising a lower housing (4), a magnet carrier (3), at least three electronic stoppers (1), and a gearbox cover (2).
The lower housing (4) accommodates a drive motor (5), a worm cluster gear (6), an idler gear (7), and a lift gear (8). The drive motor (5) drives the worm cluster gear (6). The worm cluster gear (6) meshes with the idler gear (7). Further, the idler gear (7) is configured to drive the lift gear (8) in response to the motion provided by the worn cluster gear (6).
The lift gear (8) accommodates a locking mechanism (not shown). The locking mechanism has a lock bolt (9). Further, the lift gear (8) is snapped with the magnet carrier (3) thereon. The magnet carrier (3) rotates whenever the lift gear (8) rotates. Further, the magnet carrier (3) has a magnet (3a) embedded thereon. The arrangement of the lower housing (4) is made in such a way that, whenever the lift gear (8) rotates along with the magnet carrier (3), the lock bolt (9) moves in up and down direction to perform locking and unlocking of the steering column.
During any cycle of the lock bolt (9), it is very important to know the status and position of the lock bolt (9). The plurality of electronic stoppers (1) are placed at locking and unlocking ends to monitor the position of the lock bolt (9) through the magnet (3a) embedded in the magnet carrier (3). In an exemplary embodiment, the electronic stoppers (1) are Hall Effect sensors. When the magnet carrier (3) rotates and the magnet (3a) comes in the range of the electronic stoppers (1), it triggers and gives a signal to a controller (not shown). Sometimes, the magnet carrier (3) rotates very fast if the input speed is high due to some external factors. In these conditions, as it possesses a high moment of inertia, there is the possibility that the magnet (3) travels more and goes far away from the electronic stoppers (1). This results in the error in the position detection of the lock bolt (9) and the ESCL assembly (10) fails to perform the function.
To overcome these issues, the gearbox cover (2) is provided with a secondary stopper (2a). The gearbox cover (2) blankets the whole ESCL assembly (10) and fitted on the lower housing (4) by means of a plurality of screws. Additionally, the electronic stoppers (1) along with other electronic components are soldered to a Printed Circuit Board Assembly (PCBA) (not shown). Further, this PCBA is screwed on the gearbox cover (2).
The secondary stopper (2a) is incorporated in the gearbox cover (2). Here, the secondary stopper (2a) is a backup mechanical stopper. The secondary stopper (2a) has a first stopping face (2ai) and a second stopping face (2aii). Additionally, the secondary stopper (2a) is designed to perform the secondary stopping function and to make the ESCL assembly (10) full proof due to the backup option. Further, the secondary stopper (2a) controls the rotation of the magnet carrier (3) within the range of the electronic stoppers (1). Due to which even if the magnet carrier (3) rotates more due to high inertia, it will be stopped within the range of the electronic stoppers (1) by hitting the first and second stopper faces (2ai, 2aii) in locking and unlocking respectively. This results in the tracking of the lock bolt (9) position by the electronic stoppers (1) accordingly. The secondary stopper (2a) is designed in a shape that stopping (hitting) faces of the secondary stopper (2ai, 2aii) makes maximum contact with the face of the magnet Carrier (3). This helps to relieve the stress during impact.
In an exemplary embodiment, if the ESCL assembly (10) does not include the electronic stoppers (1), then the magnet carrier (3) hits the secondary stopper (2a) in every cycle. The secondary stopper (2a) is strong enough to sustain the loads for a high number of cycles.

Advantages of the invention:
1. The assembly (10) of the present invention provides an anti-theft purpose for the automotive vehicle in case of ESCL assembly failure.
2. The assembly (10) of the present invention is designed to perform the secondary stopping function and the system becomes full proof due to the backup option.
3. The secondary stopper of the present invention is an integral part of the gearbox cover (2) which sustains the impact of the magnet carrier (3) due to the high moment of inertia.
4. The secondary stopper of the present invention is incorporated in the gearbox cover only, there is no separate arrangement required for stopping. Thus, the cost associated with the additional part is eliminated. Also, the solution is simple yet very useful and compact.
5. The secondary stopper of the present invention is designed in such a way that the hitting faces of the secondary stopper make maximum contact with the Magnet Carrier’s face. This helps to relieve the stress during impact.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention.