FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
Title:
ELECTRICALLY OPERATED TELESCOPIC CUM FOLDABLE
FOOT-STEP ASSEMBLY IN A VEHICLE & METHOD FOR
OPERATING THE SAME
Applicant: MAHINDRA & MAHINDRA LIMITED
GATEWAY BUILDING, APOLLO BUNDER,
MUMBAI-400001,
MAHARASHTRA, INDIA.
Inventors:
R. R. SAKTHIVEL S. SUDARSANAM
S. SRINIVASAN G. BALA JI
T. RAVIKUMAR
All Indian,Nationals.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF INVENTION
The present invention relates to a compact arrangement for climbing on or alighting from an automobile. In particular, the present invention relates to a foldable-cum-telescopic foot-step assembly. More particularly, the present invention relates to an electrically operable telescopic-cum-foldable foot-step assembly for vehicles with high ride-height, e.g. tractors.
The invention also relates to a method for operating the foldable-cum-telescopic foot-step assembly by the driver for climbing on and alighting from the vehicle.
BACKGROUND OF THE INVENTION
An automobile with a high ride-height or ground-clearance, e.g. tractor often has to move over rough and undulating surfaces, such as agricultural fields. During manoeuvers over such fields, the driver has to take precautions, so that the foot-steps and clutch housing do not hit bunds or other raised obstacles. Usually, a foot-step is provided in the tractor for facilitating the tractor driver to climb on and alighting from the high-position tractor seat.
DISADVANTAGES WITH THE PRIOR ART
It has always been a problem during operation and movement of the tractor on field work that fixed footstep is prone to hitting the high bunds and/or raised obstacles or to get stuck thereon. This hinders the trouble-free movement of the tractor over fields. This also causes serious damages to the footstep and sometimes the footstep or the clutch housing mounting area even gets broken.
Therefore, there is an existing need to improve the fixed footstep of high ride-height vehicles, such as tractors by introducing a foldable and vertically movable foot-step arrangement. This would ensure to selectively adjust the ground clearance according to the field condition, so as to prevent any damage to the footstep and/or clutch housing of such high ride-height vehicles during field operation thereof.

OBJECTS OF THE INVENTION
Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:
An object of the present invention is to provide compact arrangement to the driver of high ride-height vehicle for climbing on or stepping down therefrom.
Another object of the present invention is to provide foldable-cum-telescopic climbing or alighting arrangement for high ride-height vehicle drivers.
Still another object of the present invention is to provide electrically operated climbing or alighting arrangement for high ride-height vehicle drivers.
Yet another object of the present invention is to provide electrically operated arrangement for selective operation by the driver for climbing or alighting from high ride-height vehicle.
A further object of the present invention is to provide an electrically operated arrangement for preventing damage to the foot-step assembly or clutch housing of the high ride-height vehicles during field operation thereof.
These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an electrically operable telescopic-cum-foldable foot-step assembly for high ride-height vehicles, the assembly comprising:
- a vertically moveable, foldable foot-step assembly,

- a telescopic actuator unit for vertical movement of the folded foot-step assembly,
- an electrically driven mechanism operable by means of a two-way toggle switch for winding and unwinding the connector to the foot-step assembly,
- a mechanism provided for locking of the foot-step assembly from rotation about the telescopic actuator axis, and
- a pair of limit switches for restricting the upper and lower limits of the footstep ground clearance,
wherein the assembly is mounted on the vehicle skid mounted sheet metals by means of a plurality of brackets and fasteners and the upper limit switch restricts the upward movement of the folded foot-step assembly to a maximum ground clearance and the lower limit switch restricts the downward movement to a minimum ground clearance by means of the telescopic actuator unit and unfolding of foot-step by final unwinding of the connector engaged at an anchoring point on the foot-step.
Typically, the foot-step assembly comprises:
a horizontally disposed profiled foot-step frame open at the side turned away from the telescopic actuator unit,
a profiled foot-step disposed inside the foot-step frame and provided with a plurality of openings, the foot-step being pivotable within the foot-step frame for upwards folding movement towards the rear vertical side thereof,
a connector with its first end engaged at an anchoring point provided on the rear upper surface of the foot-step, the anchoring point being disposed in a vertical plane of the connector and carrier thereof,
a gap configured between the rear vertical edge of the foldable foot-step and the foot-step frame for passage of the connector thereunder, and
a lower limit switch disposed under the outer side of the foot-step to provide a predetermined minimum ground clearance for alighting.

Typically, the telescopic actuator unit comprises:
- a vertically disposed hollow cylinder open at both ends thereof and securely mounted on the vehicle chassis by means of a plurality of brackets and fasteners provided at upper and lower-end thereof, and
- a piston with a piston head sliding inside the hollow cylinder, .
wherein the hollow cylinder is provided with a reduced diameter opening at the lower end thereof, the reduced diameter opening configured to allow the vertical sliding movement of the piston inside the hollow cylinder.
Typically, the electrically driven mechanism comprises:
- an electric motor operable in forward and reverse direction and securely mounted on the vehicle chassis,
- the electric motor shaft supporting a carrier for winding the connector with one end thereof fixed on the circumference thereof at a predetermined point and the other end thereof engaged at an anchoring point provided on the rear upper surface of the foot-step.
Typically, the foot-step assembly rotational locking mechanism comprises:
- a shaft for locking of the foot-step assembly from rotation about the telescopic actuator axis, the shaft being guided in a guide-cylinder fixed on a bracket on the cylinder, which in turn is mounted on the vehicle chassis,
wherein, the lower end of the shaft loosely rests against the rear vertical side of the foot-step frame to prevent the foot-step assembly from rotating about telescopic actuator unit on winding of the connector by electric motor.
Typically, the upper limit switch is fixed at the upper peripheral end of the cylinder duly aligned with the upper end of the rotational locking shaft for restricting the vertical movement of the foot-step assembly to a predetermined maximum ground clearance.

Typically, the lower limit switch is fixed under the outer edge of the foot-step to be unfolded to a horizontal position with a predetermined minimum ground clearance.
Typically, the connector is a chain and the carrier is a sprocket, e.g. made of metal or plastics, carrying and fixing one end of the chain on the circumference thereof.
Typically, the connector is a rope and the carrier is a pulley, e.g. made of metal or plastics, carrying and fixing one end of the rope on the circumference thereof.
A method for electrically operating a telescopic-cum-foldable foot-step assembly, the method comprising the steps of:
- switching on the vehicle ignition key, and
- either turning the toggle switch towards left for winding the connector by rotating the carrier in a clock-wise direction to first fold the foot-step in an upward direction, subsequently pulling the connector further to lift the footstep aseembly with the folded foot-step by means of the telescopic actuator unit connected to the foot-step frame,
- stopping the vertically upward movement of the foot-step assembly automatically on upper limit switch coming in contact with the upper end of the rotation locking shaft, whereby the folded foot-step is maintained at a position of maximum ground clearance for field operation of the vehicle, and
- preventing the electric motor to operate on further turning of the toggle switch in clock-wise direction by the driver;
- or turning the toggle switch towards right for operating the elecric motor in a reversed or anticlockwise direction for unwinding the connector from the the carrier for lowering the foot-step assembly,

- lowering the foot-step assembly to a predetrmined height to reach the lower-most horizontal position when the outer edge of the foot-step comes in contact with the lower limit switch disposed thereunder and stopping the electric motor operation o keep the foot-step assembly in this lower-most position with the minimum ground clearance for facilitating the driver to climb on or alight from the vehicle, and
- preventing the electric motor from rotation in the anticlockwise direction by a further turning of the toggle switch to the right.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present invention will be briefly described with reference to the accompanying drawings, which include:
Figure 1 shows a telescopic actuator unit for an electrically operated foldable-cum-telescopic foot-step assembly in accordance with the invention.
Figure 2 shows an embodiment of the chain-driven exemplary electrically operated foldable-cum-telescopic foot-step assembly in accordance with the present invention mounted on a tractor (not shown).
Figure 3 shows another exemplary embodiment of the rope-driven electrically operated foldable-cum-telescopic foot-step assembly in accordance with the present invention mounted on a tractor (not shown).
Figure 4a shows a front-view of the chain-driven exemplary embodiment shown in Figure 2.
Figure 4b shows a right-side view of the chain-driven exemplary embodiment shown in Figure 2.
Figure 4c shows a top-view of the chain-driven exemplary embodiment shown in Figure 2.

Figure 5 shows a left-side view of the chain-driven exemplary embodiment shown in Figure 2.
Figure 6a shows a front-view of the rope-driven exemplary embodiment shown in Figure 3.
Figure 6b shows a right-side view of the rope-driven exemplary embodiment shown in Figure 3.
Figure 6c shows the top-view of the rope-driven exemplary embodiment shown in Figure 3.
Figure 7 shows the left-side view of the rope-driven exemplary embodiment shown in Figure 3.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.
Figure 1 shows a telescopic actuator unit A for an electrically operated foldable-cum-telescopic foot-step assembly in accordance with the invention. It consists of a long hollow cylindrical body 100 and a piston 200, which is axially guided inside the hollow cylinder cavity. Here, the cylindrical body 100 is sectioned along face B and C thereof, for clearly showing the position of the piston 200 of diameter d2 configured with a piston head 210 of diameter d1. The lower end of the piston 210 is fixed on the frame of the foot-step assembly shown in Figs. 2 and 3 described below.
Figure 2 shows an exemplary embodiment of the chain-driven electrically operated foot-step assembly in accordance with the present invention mounted on a tractor (not shown). The foot-step assembly includes a foldable foot-step 12. The cylinder 100 of the telescopic actuator unit A is mounted on the tractor body by means of mounting brackets 16 and 22 by suitable

fasteners. An electric motor 10 operated and chain-driven foot-step folding mechanism is also mounted on the tractor body. The chain-drive includes a chain 30 with its upper end fixed on a metal or plastic sprocket 18 rotatable by means of a reversibly driven electric motor 10 and the lower end of the chain 30 is fixed at anchoring point 28 adjacent the rear edge of the foot-step 12. The lower limit switch 24a is disposed under the outer edge 34 of the foot-step 12. By operating the electric motor 10, the sprocket 18 can be selectively rotated to wind or unwind the chain 30. Accordingly, viewing in the direction of arrow X, the chain 30 is wound on the sprocket 18 by a clockwise rotation thereof for pulling the lower chain end fixed on foot-step 12, which in turn folds the foot-step upwards. The foot-step 12 is stopped in its vertical position during upward movement thereof by coming in contact with the rear vertical side 32 of the foot-step frame. A shaft 26 is also provided fixed parallel to the piston 200 and its upper end is mounted at the lower peripheral end of the cylinder 100, which in turn is fixed on the chassis by the mounting bracket 16. The lower end of the shaft 26 loosely rests against the rear vertical side 32 of the foot-step frame in order to stop the foot-step 12 from rotating about the axis of the telescopic actuator unit, when chain 30 is wound on the sprocket, thereby steadying the vertical sliding movement of the folded foot-step 12. On winding further on the sprocket 18, the chain 30 pulls the folded foot-step assembly upwards by means of the vertical sliding movement of the piston 200 inside the cylinder 100. An upper limit switch 24b is fixed in alignment with the axis of the shaft 26, which acts as the upper stopper to restrict the vertical sliding movement of the folded foot-step 12 to a predetermined highest position corresponding to the maximum desirable ground clearance of the foot-step 12. As soon as the upper end of shaft 26 comes in contact with the upper limit switch 24b, the electric motor 10 stops and chain-drive is immediately stopped in this position, in which the foot-step 12 is in a folded and upper-most position thereof. With this position of maximum ground clearance, the driver while sitting in his seat can avoid any damage to the footstep or clutch housing, because there is no possibility of the foot-step being hit by any bund or obstacle during the field operation of the tractor. On the contrary, when the vehicle is stationary and the driver wants to alight from the tractor, he activates the electric motor 10 in an opposite direction by means of the toggle switch (not shown), which causes the sprocket 18 to rotate in anti-

clockwise direction when viewed in the direction of the arrow X. This unwinds the chain 30 from the sprocket 18 and thereby the foot-step 12 moves vertically downwards due to its own weight aided and guided by the piston 200 moving down inside the cylinder 100. A further unwinding of the chain 30 facilitates unfolding of the foot-step 12 and it is fully opened. As soon its outer edge 34 touches the lower limit switch 24a, the electric motor 10 stops and chain-drive is held in this position, allowing the driver to step-down from the tractor. This position also allows the driver to climb on the foot-step 12 to get seated on his seat for field operation of the tractor.
Figure 3 shows an exemplary embodiment of the rope-driven electrically operated foldable-cum-telescopic foot-step in accordance with the present invention mounted on a tractor (not shown). Here, the mechanism of chain 30 and sprocket 18 shown in Figure 2 is replaced by another mechanism of rope 30' and pulley 18'. The rest of the operation of this rope-driven mechanism (30', 18') is similar to the chain-sprocket (30, 18) mechanism shown in the Figure 2.
Figure 4a shows a front-view of the chain-driven exemplary embodiment shown in Figure 2. Here, the foot-step 12 is shown in an open position, i.e. the piston 200 is in its lower-most position with its head 210 resting on the bottom side opening of the cylinder 100. As soon as the outer edge 34 of the foot-step 12 reaches this position, the lower limit switch 24a disposed thereunder switches-off the power supply to the electric motor 10. Typically, the electric motor 10 is power window motor, which can operate in forward as well as in reverse direction, so that the chain drive can be selectively driven to wind or unwind the chain 30 on the sprocket 18 for folding or unfolding the foot-step 12 and to move folded foot-step 12 vertically raising or lowering by means of the cylinder 100 and piston 200 assembly of the telescopic actuator unit. This figure also illustrates the vertical alignment of the upper limit switch 24b and, the axis of the rotational locking shaft 26. This arrangement is suitably used to limit the vertical upward sliding movement of the foot-step assembly with the folded foot-step 12. This shaft 26 also helps in preventing the foot-step 12 to rotate about the axis of the telescopic actuator unit during upward pulling of the chain 30 by rotating the sprocket 18. As soon as the upper end of this

shaft 26 touches the upper limit switch 24b, the power supply to the electric motor 10 is switched-off and the foot-step 12 remains in its folded and highest position (not shown) allowing maximum ground clearance of the foot-step 12.
Figure 4b shows a right-side view of the chain-driven exemplary embodiment shown in Figure 2. Here, the sprocket 18 is shown in with chain 30 in fully unwound condition, which corresponds to unfolded and lowered foot-step 12, e.g. to facilitate the driver to alight from the tractor easily.
Figure 4c shows a top-view of the chain-driven exemplary embodiment shown in Figure 2, clearly showing the layout of the electric motor 10, motor shaft 10s, sprocket 18 and chain 30 connected to foot-step 12 at anchoring point 28. The concentric positioning of the cylinder 100 and piston 200 with its head 210 sliding inside the cylinder 100 is also illustrated in this figure. A gap M is also provided between the foot-step 12 and the frame pivotably supporting the same, which facilitates ease of folding and unfolding of the foot-step 12.
Figure 5 shows the left-side view of the chain-driven exemplary embodiment shown in Figure 2 showing the chain 30 and sprocket 18 mechanism connected to the foot-step 12.
Figure 6a shows the front-view of the rope-driven exemplary embodiment shown in Figure 3. The view is similar to Figure 4a, with the exception of chain 30 and sprocket 18 replaced by rope 30' and pulley 18' respectively.
Figure 6b shows the right-side view of the rope-driven exemplary embodiment shown in Figure 3. The view is similar to Figure 4b, with the exception of chain 30 and sprocket 18 replaced by rope 30' and pulley 18' respectively.
Figure 6c shows the top-view of the rope-driven exemplary embodiment shown in Figure 3. The view is similar to Figure 4c, with the exception of chain 30 and sprocket 18 replaced by rope 30' and pulley 18' respectively

Figure 7 shows the left-side view of the rope-driven exemplary embodiment shown in Figure 3. The view is similar to Figure 5, with the exception of chain 30 and sprocket 18 replaced by rope 30' and pulley 18' respectively
WORKING PRINCIPLE OF THE INVENTION
The electrically operated foldable-cum-telescopic foot-step arrangement in accordance with the invention is fixed below the LH side floor panel for climbing on and alighting from a tractor. The driver can climb to his seat by using this foldable foot-step 12, which is normally in an open position. Once the driver sits on the driver's seat, he can switch on the tractor ignition key for supplying 12v DC power supply to the entire electric system of the tractor including the inventive arrangement. With power being on in the electrical circuits via vehicle batteries, the foldable-cum-telescopic foot-step in accordance with the present invention can be operated with the help of double-position toggle switch as described below:
- When turned towards left, the toggle switch (not shown) provides DC supply to the electric motor (power window motor) 10, which starts rotating in a clock-wise direction (when seen in the direction of arrow X in Fig. 2).
- By the clockwise rotation of the sprocket 18 or pulley 18' connected to electric motor 10 via shaft 10s, which carries a chain 30 or rope 30", initially the foot-step 12 is pulled back in an upward direction by about 90° and then the foot-step 12 comes to rest against rear vertical side 32 of the footstep frame 20.
- A further rotation of the electric motor 10 pulls the chain 30 or rope 30' further to raise the complete foot-step assembly 20 by means of the vertical sliding action of the telescopic actuator unit.
- This upward movement will reduce the total height of the foot-step assembly 20, e.g. by about 130 mm from its initial position.
- As soon as the foot-step assembly 20 reaches the desired height, the limit switch 24b aligned with the rotational locking shaft 26 acts as the upper

stopper to limit the vertical sliding movement of the foot-step assembly 20 and once the upper end of shaft 26 comes in contact with the upper limit switch 24b, the electric motor 10 is stopped and chain or rope drive is also stopped in this position having the foot-step 12 is in folded and the footstep assembly 20 in its upper-most position allowing maximum ground clearance.
- After the power supply is disconnected, even if the toggle switch is turned further in clock-wise direction by the operator, the DC motor will not operate.
- With this upper-most position of the foot-step assembly 20, the tractor can be moved on field with increased ground clearance of the foot-rest assembly 20 and therefore, preventing any bund hit, so avoiding any possibility of damage to foot-rest assembly and/or and clutch housing.
- Once the field operation is over or whenever the driver wants to step down from the tractor, he just needs to operate the toogle switch in the opposite (right) direction. This will enable to operate the elecric motor 10 to rotate in a reversed or anticlockwise direction, whereby sprocket 18 or pulley 18' along with chain 30 or rope 30' will also rotate in the anticlockwise direction to facilitate in losening or unwinding of the chain 30 or rope 30' from the sprocket 18 or pulley 18'.
- With this chain 30 or rope 30' loosening, the foot-step assembly 20 will slide down, e.g. by about 130 mm and further allows to unfold the footstep 12 to come to a horizontal position (Figure 2) convenient for climbing on or alighting from the tractor. Now, the outer edge 34 of the foot-step 12 comes in contact with the lower limit switch 24a disposed thereunder and the power supply to the electric motor 10 is disconnected and the foot-step 12 remains there in its lower-most position.
- Now, even if the driver keeps turning the toggle switch to the right, the electric motor cannot be rotated further in the anticlockwise direction.
- This position will enable the driver to step-down from the tractor.

Technical advantages and economic significance
• Prevents any damage to foot-step assembly or clutch housing.
• Simple construction operable by low-power DC electric motor, e.g. power window motor.
• Safe for field operations.
• Automatic switching by limit switches, requiring no driver intervention for adjusting the foot-step folding or assembly height for achieving minimum or maximum ground clearance.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.
The use of the expression "a", "at least" or "at least one" shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.
The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.
Although, only the preferred embodiments have been described herein, the skilled person in the art would readily recognize to apply these embodiments with any modification possible within the spirit and scope of the present invention as described in this specification.
Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents,

components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.
The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.
While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention.
These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim:
1. An electrically operable telescopic-cum-foldable foot-step assembly for
high ride-height vehicles, the assembly comprising:
- a vertically moveable, foldable foot-step assembly,
- a telescopic actuator unit for vertical movement of the folded foot-step assembly,
- an electrically driven mechanism operable by means of a two-way toggle switch for winding and unwinding the connector to the foot-step assembly,
- a mechanism provided for locking of the foot-step assembly from rotation about the telescopic actuator axis, and
- a pair of limit switches for restricting the upper and lower limits of the foot-step ground clearance,
wherein the assembly is mounted on the vehicle skid mounted sheet metals by means of a plurality of brackets and fasteners and the upper limit switch restricts the upward movement of the folded foot-step assembly to a maximum ground clearance and the lower limit switch restricts the downward movement to a minimum ground clearance by means of the telescopic actuator unit and unfolding of foot-step by final unwinding of the connector engaged at an anchoring point on the foot-step.
2. The telescopic-cum-foldable foot-step assembly as claimed in claim 1,
wherein the foot-step assembly comprises:
a horizontally disposed profiled foot-step frame open at the side turned away from the telescopic actuator unit,
a profiled foot-step disposed inside the foot-step frame and provided with a plurality of openings, the foot-step being pivotable within the footstep frame for upwards folding movement towards the rear vertical side thereof,

a connector with its first end engaged at an anchoring point provided on the rear upper surface of the foot-step, the anchoring point being disposed in a vertical plane of the connector and carrier thereof,
a gap configured between the rear vertical edge of the pivoted foldable foot-step and the foot-step frame for passage of the connector thereunder, and
a lower limit switch disposed under the outer edge of the foot-step to provide a predetermined minimum ground clearance for alighting.
3. The telescopic-cum-foldable foot-step assembly as claimed in claim 1,
wherein the telescopic actuator unit comprises:
- a vertically disposed hollow cylinder open at both ends thereof and securely mounted on the vehicle chassis by means of a plurality of brackets and fasteners provided at upper and lower-end thereof, and
- a piston with a piston head sliding inside the hollow cylinder,
wherein the hollow cylinder is provided with a reduced diameter opening at the lower end thereof, the reduced diameter opening configured to allow the vertical sliding movement of the piston inside the hollow cylinder.
4. The telescopic-cum-foldable foot-step assembly as claimed in claim 1,
wherein the electrically driven mechanism comprises:
- an electric motor operable in forward and reverse direction and securely mounted on the vehicle chassis,
- the electric motor shaft supporting a carrier for winding the connector with one end thereof fixed on the circumference thereof at a predetermined point and the other end thereof engaged at an anchoring point provided on the rear upper surface of the foot-step.
5. The telescopic-cum-foldable foot-step assembly as claimed in claim 1,
wherein the foot-step assembly rotational locking mechanism comprises:

- a shaft for locking of the foot-step assembly from rotation about the telescopic actuator axis, the shaft being guided in a guide-cylinder fixed on a bracket on the cylinder, which in turn is mounted on the vehicle chassis,
wherein, the lower end of the shaft loosely rests against the rear vertical side of the foot-step frame to prevent the foot-step assembly from rotating about telescopic actuator unit on winding of the connector by electric motor.
6. The telescopic-cum-foldable foot-step assembly as claimed in claim 1, wherein the upper limit switch is fixed at the upper peripheral end of the cylinder duly aligned with the upper end of the rotational locking shaft for restricting the vertical movement of the foot-step assembly to a predetermined maximum ground clearance.
7. The telescopic-cum-foldable foot-step assembly as claimed in claim 1, wherein the lower limit switch is fixed under the outer edge of the foot-step to be unfolded to a horizontal position with a predetermined minimum ground clearance.
8. The telescopic-cum-foldable foot-step assembly as claimed in claim 1, wherein the connector is a chain and the carrier is a sprocket, e.g. made of metal or plastics, carrying the chain on the circumference thereof.
9. The telescopic-cum-foldable foot-step assembly as claimed in claim 1, wherein the connector is a rope and the carrier is a pulley, e.g. made of metal or plastics, carrying the rope on the circumference thereof.
10. Method for electrically operating a telescopic-cum-foldable foot-step assembly as claimed in anyone of the claims 1 to 9, the method comprising the steps of:
- switching on the vehicle ignition key, and

- either turning the toggle switch towards left for.winding the connector by rotating the carrier in a clock-wise direction to first fold the foot-step in an upward direction, subsequently pulling the connector further to lift the foot-step aseembly with the folded foot-step by means of the telescopic actuator unit connected to the foot-step frame,
- stopping the vertically upward movement of the foot-step assembly automatically on upper limit switch coming in contact with the upper end of the rotation locking shaft, whereby the folded foot-step is maintained at a position of maximum ground clearance for field operation of the vehicle, and
- preventing the electric motor to operate on further turning of the toggle switch in clock-wise direction by the driver;
- or turning the toggle switch towards right for operating the elecric motor in a reversed or anticlockwise direction for unwinding the connector from the the carrier for lowering the foot-step assembly,
- lowering the foot-step assembly to a predetrmined height to reach the lower-most horizontal position when the outer edge of the foot-step comes in contact with the lower limit switch disposed thereunder and stopping the electric motor operation o keep the foot-step assembly in this lower-most position with the minimum ground clearance for facilitating the driver to climb on or alight from the vehicle, and
- preventing the electric motor from rotation in the anticlockwise direction by a further turning of the toggle switch to the right.