DESC:FIELD OF INVENTION
The present invention relates generally to a self-propelled all-terrain multipurpose land vehicle able to perform a multitude of load transferring tasks. More particularly, the present invention relates to a multipurpose land vehicle with enhanced ground clearance and wider stance. Advantageously, the present invention maintains grip on the road during adverse weather conditions. Further, the present invention maintains traction on the road in mud or on gravel in order to keep the vehicle stable and increase the overall level of traction while towing.

BACKGROUND OF INVENTION
A multipurpose land vehicle generally provides the power and traction to mechanize agricultural tasks such as tillage, implements may be towed behind or mounted on the multipurpose land vehicle and said multipurpose land vehicle may also provide a source of power if the implement is mechanised.

The multipurpose land vehicle comprises a frame on which the wheels are mounted and driven by the drive system. The multipurpose land vehicles are provided with two wheel steering system. The two wheel steering system is the conventional steering arrangement which is in use to turn the front wheels using a hand operated steering wheel positioned in front of the driver via steering column. However, the two wheel steering system require fairly larger turning radius. In certain terrains there will be limitations in the width of the passage, where it may be very difficult to steer the vehicle safely.

The frames of the conventional multipurpose land vehicles are very rigid and almost do not permit twisting. In the known multipurpose land vehicles such as tractors since the wheels are mounted on the frame directly there is a limitation in the ground clearance, which is less than half of the wheel diameter. Due to the limited ground clearance, the conventional multipurpose land vehicles are not suitable for use in terrains where irregularities or obstacles such as wooden logs are present.

In order to overcome the limitations in the ground clearance, it is necessary to use large diameter drive wheels which are very expensive. The installation of the larger diameter drive wheels again require oversized transmissions to provide required torque to drive the larger diameter drive wheels. The driving of the larger wheels is also associated with the requirement of enhanced power source which are not only very heavy but also increases its initial and operating cost.

Traditional multipurpose land vehicle of the like tractors have a unsafe condition called tip over which is reported in many of the accidents in tractors.

Accordingly, there exists a need for a multipurpose land vehicle with increased ground clearance. Further, there exists a need for a multipurpose land vehicle which maintains a proper grip on the road during adverse weather conditions. Further, there exists a need for a multipurpose land vehicle which maintains a proper grip on the road in mud or on gravel in order to keep the vehicle stable and increase the overall level of traction while towing.

OBJECTS OF INVENTION
One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention.
The primary object of the present invention is directed to provide a multipurpose land vehicle constructed with enhanced ground clearance.

It is another object of the present invention is directed provide a multipurpose land vehicle in which the load is equally distributed in all the four driven wheels thereby increasing the traction as well as preventing the occurrence of tip over condition.

It is another object of the present invention to provide a multipurpose land vehicle, which allows all the wheels to be in contact with the ground during working of the vehicle in both even and uneven terrain.

It is another object of the present invention to provide a multipurpose land vehicle with four wheel drive, which is capable to maintain grip on various terrains during adverse weather conditions.

It is another object of the present invention to provide a multipurpose land vehicle with four wheel drive, which is capable to maintain grip on the road in mud or on gravel in order to keep the vehicle stable and increase the overall level of traction while towing.

It is another object of the present invention to provide a multipurpose vehicle with four wheel drive, which does not interrupt articulation of suspension system.

It is another object of the present invention to provide a multipurpose vehicle comprising of a floating frame comprises of at least two first members and at least two second members forming a frame and has a pivot point at each of the respective members.
It is another object of the present invention to provide a multipurpose vehicle having an interlinked articulated suspension system comprises of ‘C’ shaped arms arranged on both sides, which are disposed to carry respective drive wheels through one or more transmission and reduction gears.

It is another object of the present invention to provide a multipurpose vehicle wherein floating frame that houses the transmission arrangement, steering arrangement and an engine is positioned on the interlinked articulated suspension system.

It is another object of the present invention to provide a multipurpose vehicle wherein ‘C’ shaped arms arranged on both sides are interlinked by a rocker arm set up which has a rocker arm which are pivoted at the centre of both front and rear second member.

It is another object of the present invention to provide a multipurpose vehicle wherein tilt angle of the floating frame is half of that of vehicle’s tilt angle so that articulation of the suspension system does not affect the frame.

It is another object of the present invention to provide a multipurpose vehicle with interlinked articulated suspension system.

It is another object of the present invention, wherein the ‘C’ shaped arms arranged on both sides are interlinked by a rocker arm set up which has a rocker arm that is pivoted at the centre of both front and rear second members.
It is another object of the present invention, wherein the interlinked articulated suspension system allows all the four wheels to contact with the ground in order to provide effective traction during the travel of the multipurpose vehicle in both even and uneven terrain.

It is another object of the present invention, wherein the interlinked articulated suspension allows high articulation of one wheel height, so that the vehicle can pass over an obstacle of height of the wheel.

It is another object of the present invention, wherein the interlinked articulated suspension enables high ground clearance which gives the vehicle high off road capability.

It is another object of the present invention, wherein the interlinked articulated suspension system provides enhanced ground clearance, which allows a tow bar system to be mounted under carriage that helps for the even distribution of weight to all drive wheels.

It is another object of the present invention, wherein the traction is equal and part of the pulled or towed load is transferred to the floating frame, so that the traction is increased that enable the vehicle to pull loads that are greater than weight of the multipurpose vehicle.

It is another object of the present invention, wherein power transmission from the engine to the four wheels is conveyed through the transmission arrangement from which drive shaft splits into left hand side and right hand side.

It is another object of the present invention, wherein from the left hand side and right hand side, the drive shaft again splits to respective front and rear reduction hub gear box on which the wheels are mounted.

It is another object of the present invention, wherein the transmission arrangement includes but not limited to a continuously variable transmission (CVT), gear box, differential.

It is another object of the present invention, wherein a light duty gear box with low reduction mounted on the floating frame and heavy duty reduction gear box with high reduction that are mounted at each wheel end.

It is another object of the present invention, wherein the transmission arrangement is light on the floating frame and heavy on the wheels to have centre of gravity of the vehicle within base in order to enhance the stability of the multipurpose vehicle.

It is another object of the present invention wherein the multipurpose vehicle provided with four wheel steering arrangement allows small turning radius mode, crab mode, zero radius mode and articulation of the suspension system.

It is another object of the present invention, wherein rotation of the steering wheel is transmitted to all the wheels through a rack and pinion steering gear.

It is another object of the present invention, wherein in the rack and pinion steering gear, the rack’s movement is converted into rotational movement at the centre which splits into front and rear which in turn steers the wheels in the respective direction.
SUMMARY OF THE INVENTION
Thus according to the embodiment of the present invention there is provided a multipurpose land vehicle with four wheel drive comprising of a floating frame, an interlinked articulated suspension system, a transmission arrangement and a steering arrangement.

It is another aspect of the present invention, wherein the floating frame comprises a left side long member, right side long member, a front cross member and a rear cross member which are joined and formed as a frame having 4 pivot points each one is arranged at the centre of the members.

It is another aspect of the present invention, wherein the articulated suspension comprised of a ‘C’ shaped arm LH provided with pivot pin, a ‘C’ shaped arm RH provided with pivot pin, a rocker arm assembly LH having pivot pin a rocker arm assembly RH having pivot pin.

It is another aspect of the present invention, wherein the ‘C’ shaped arm LH the ‘C’ shaped arm RH are inter linked by the rocker arm assembly LH and the rocker assembly RH.

It is another aspect of the present invention, wherein the articulated suspension system is pivotally supported at pivot points (PP1,PP2,PP3 and PP4) of the floating frame by the pivot pins (P1, P2,P3 and P4).

It is another aspect of the present invention, wherein the transmission arrangement comprising an engine which transmits power via a transmission arrangement to a gear box that transmits drive to a differential.

It is another aspect of the present invention, wherein the differential split the drive into LH side drive & RH drive and the transmitted to a power split gear box LH and to a power split gear box RH.

It is another aspect of the present invention, wherein the power is transmitted to a front reduction hub gear box LH, rear reduction hub gear box LH and to respective wheels attached to them through power split gear box LH, angle gear front LH and angle gear rear LH.

It is another aspect of the present invention, wherein the power is transmitted to a front reduction hub gear box RH and a rear reduction hub gear box RH and to respective wheels attached to them through power split gear box RH, angle gear front RH and an angle gear rear RH.

It is another aspect of the present invention, wherein the steering arrangement is a four wheel.
It is another aspect of the present invention, wherein the steering arrangement comprises a rack and pinion steering gear comprising a rack LH and a rack RH.

It is another aspect of the present invention, wherein the operation of the steering gear through the rack LH and the rack RH incorporates rotary motion to drive shaft LH and the drive shaft RH.

It is another aspect of the present invention, wherein the rotary motion of the drive shaft LH and the drive shaft RH through the worm and segment gears that turn the wheels fitted to the respective reduction hub gear box.

It is another aspect of the present invention comprises a hydrostatic pump which pumps and supply hydraulic fluid to a steering valve which is activated by the operation of the steering wheel.

It is another aspect of the present invention, wherein the steering valve operates the hydrostatic motors to incorporate rotary motion to the worms.

It is another aspect of the present invention, wherein the worm are in drive engagement with the segment gears respectively that turn the wheels fitted to the respective reduction hub gear box to steer the vehicle.

It is another aspect of the present invention, wherein the transmission arrangement is continuously variable transmission (CVT).

It is another aspect of the present invention, wherein the reduction hub gear box LH, the rear reduction hub gear box LH, the reduction hub gear box RH and the rear reduction hub gear box RH which are mounted on the wheel of the vehicle are heavy duty reduction gear box of higher weight with high reduction ratio.

It is another aspect of the present invention, wherein the power split gear box LH, the angle gear front LH, the angle gear rear LH, the power split gear box RH, the angle gear front RH and the angle gear rear RH which are mounted on the floating frame are light duty gear boxes of lighter weight with low reduction ratio.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1: schematically illustrates the floating frame of the multipurpose land vehicle according to the present invention.
Figure 2: schematically illustrates the articulated suspension system of the multipurpose land vehicle according to the present invention.
Figure 3: schematically illustrates the drive arrangement of the multipurpose land vehicle according to the present invention.
Figure 4: schematically illustrates the first embodiments of the steering arrangement of the multipurpose land vehicle according to the present invention.
Figure 5: schematically illustrates the second embodiment of the steering arrangement of the multipurpose land vehicle according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES
The multipurpose land vehicle according to the present invention comprising a floating frame (F), an interlinked articulated suspension system (S), a transmission arrangement of 4 wheel drive and a steering arrangement.

As shown in Figure 1 of the drawing the floating frame (F) comprises a left side long member (1), a right side long member (2), a front cross member (3) and a rear cross member (4) which are joined and formed as a frame in the shape of a rectangle /square. The floating frame (F) has 4 pivot points each one is arranged at the centre of the members namely (PP1) in the left side long member (1), (PP2) in the right side long member (2), (PP3) in the front cross member (3) and (PP4) in the rear cross member (4).

As shown in figure 2, the articulated suspension (S) system comprised of a ‘C’ shaped arm LH (5) provided with pivot pin (5a), a ‘C’ shaped arm RH (6) provided with pivot pin (6a), a rocker arm assembly LH (7) having pivot pin (7a) and a rocker arm assembly RH (8) having pivot pin (8a).The ‘C’ shaped arm LH (5) and the ‘C’ shaped arm RH (6) are inter linked by the rocker arm assembly LH (7) and the rocker assembly RH (8).

The articulated suspension system (S) is positioned outside the floating frame (F) and pivotally supported at pivot points (PP1,PP2,PP3 and PP4) by pivot pins (P1, P2,P3 and P4) in a manner the relation between the suspension system (S) and the floating frame (F) in such a manner the articulation of the suspension (S) does not affect the floating frame (F) to an extent.

The interlinked articulated suspension system as per the above construction permits all the four wheels planted on the ground at all the times even or uneven terrain, thereby providing traction all the time.

The interlinked articulated suspension system as per the above construction allows high articulation of one wheel height, so that the vehicle can pass over an obstacle of a height of one wheel.

The interlinked articulated suspension system as per the above construction facilitates high ground clearance to the vehicle provides the vehicle high off road capability.

The interlinked articulated suspension system according to the present invention provides high ground clearance which allows a tow bar system to be mounted under carriage, which in turn helps in even distribution of weight to all the 4 drive wheels, so the traction is equal and part of the pulled or towed load is transferred to the vehicle chassis, so that the traction is increased and enable the vehicle to pull greater load than its own weight.

In order to achieve all time 4 wheel drive power transmission system which does not interrupt the articulation of the suspension system the ‘C’ shaped arm LH (5) and ‘C’ shaped arm RH (6) houses the transmission and reduction gear boxes.

As shown in figure 3, the power from an engine (9) is transmitted via a transmission arrangement (10) that includes but not limited to a continuously variable transmission (CVT) to a gear box (11). From the gear box (11) the drive is transmitted to a differential (12) which split the drive into LH side drive & RH side drive and the power is transmitted to a power split gear box LH (13) and to a power split gear box RH (14).

The power split gear box LH (13) split the drive and transmits the same to an angle gear front LH (15) and to an angle gear front RH (16). Subsequently power from angle gear front LH (15) and an angle gear front RH (16) is transmitted to a front reduction hub gear box LH (17) and a rear reduction hub gear box LH (18) and transmitted to respective wheels attached to them.
Similarly the power split gear box LH (14) split the drive and transmits the same to an angle gear front RH (19) and to an angle gear rear RH (20 ). Subsequently power from the angle gear front RH (19) and angle gear rear RH (20) is transmitted front reduction hub gear box RH (21) and a rear reduction hub gear box RH (22) and transmitted to respective wheels attached to them.

The drive arrangement according to the present invention explained as above does not hinder the articulation of the suspension (S) as well as the steering angle of all the 4 wheels.
The power split gear box LH (13), the angle gear front LH (15 ), the angle gear rear LH (16), the power split gear box RH (14) , the angle gear front RH (19 ) and the angle gear rear RH (20) which are mounted on the floating frame (F) are light duty gear boxes with low reduction. On the other hand the front reduction hub gear box LH (17), the rear reduction hub gear box LH (18), the reduction hub gear box RH (21) and the rear reduction hub gear box RH (22) which are mounted on the wheel of the vehicle are heavy duty reduction gear box with high reduction.

The objective of the transmission is to be light on the frame and heavy at the wheel. This is achieved in order to lower the CG of the tall vehicle which in turn increases the stability is achieved using:
- The reduction hub gear box LH (17), the rear reduction hub gear box LH (18), the reduction hub gear box RH (21) and the rear reduction hub gear box RH (22) which are mounted on the wheel of the vehicle are heavy duty reduction gear box of higher weight with high reduction ratio.
- The power split gear box LH (13), the angle gear front LH (15), the angle gear rear LH (16), the power split gear box RH (14), the angle gear front RH (19) and the angle gear rear RH (20) which are mounted on the floating frame (F) are light duty gear boxes of lighter weight with low reduction ratio.

The multipurpose vehicle according to the present invention is provided with four wheel steering arrangement that allows different modes of steering which includes small turning radius mode, crab mode, zero radius mode and articulation of the suspension system.
In an embodiment the invention uses a rack and pinion steering gear (23) as shown in figure 4. The operation of a steering wheel activate a rack LH (24) and a rack RH (25) of the rack and pinion steering gear (23).The actuation of the rack LH (24) transmits angular motion to a drive shaft LH (26) through a pinion (27) fitted to it. Similarly the actuation of a rack RH (25) transmits rotary motion to a drive shaft RH (28) through a pinion (27’) fitted to it. The drive shaft (26) is fitted with a worm (29) at the front side and a worm (29’) at the rear side and is in drive engagement with segment gears (30, 30’) respectively fitted at the front side and rear side.

Similarly the drive shaft RH (28) is fitted with a worm (29’’) at the front side and a worm (29’’’) at the rear side and is in drive engagement with segment gears (30’’,30’’’ ) respectively fitted at the front side and rear side.

The operation of the steering wheel (23) through the steering gear (23) incorporates rotary motion to drive shaft LH (26) and the drive shaft RH (28). The drive shaft LH (26) and the drive shaft RH (28) provides angular movement through the worm (29,29’,29’’,29’’’ ) to the segment gears (30,30’,30’’,30’’’) that turn the wheels fitted to the respective reduction hub gear box (17,18,21,22) there by the vehicle is steered.

In this manner steering of the wheels in the respective direction is achieved with the help of rack and pinion steering gear. The rack’s movement is converted into rotational movement at the centre which splits into front and rear. The rotation of the steering wheel is transmitted to all the 4 wheels through a rack and pinion steering gear.

In a preferred embodiment the steering arrangement is hydrostatic type as shown in figure 5. Power from the engine (9) is transmitted to a hydrostatic pump (31) which pumps and supply hydraulic fluid to a steering valve (32).
The operation of the steering wheel actuate a steering valve (32) that operates the hydrostatic motor (33,33’,33’’and 33’’’) which in turn incorporate rotary motion to the worm (29,29’,29’’,29’’’ ) . The worm (29,29’,29’’,29’’’) are in drive engagement with the segment gears (30,30’,30’’,30’’’) respectively that turn the wheels fitted to the respective reduction hub gear box (17,18,21,22) to steer the vehicle.

The direction of rotation of the worm (29,29’,29’’,29’’’ ) are independent to each other and are determined by the hydrostatic motor (33,33’,33’’and 33’’’) respectively. The direction control of the wheel is achieved by providing direction to the valves that controls the direction of the hydrostatic motor (33,33’,33’’and 33’’’).

By this arrangement it is possible to achieve the required mode such as small turning radius mode, crab mode and normal mode according to the requirement.

Mode selection is achieved by a selector switch that provides direction control to the hydrostatic motor (33,33’,33’’and 33’’’).

Advantages of the present invention are:
• Lesser fuel consumption for operating the vehicle due to reduction in weight of the vehicle.
• Provides relatively high ground clearance.
• Four wheel drives maintain grip on the road and increase the overall level of traction.
• Four wheel steering arrangement allows different mode of steering which are small turning radius mode, crab mode, zero radius mode and standard mode .
Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the invention. ,CLAIMS:WE CLAIM
1. A multipurpose land vehicle with four wheel drive comprising of:
a floating frame (F);
an interlinked articulated suspension system (S);
a transmission arrangement; and
a steering arrangement,
wherein the floating frame (F) comprises a left side long member (1), right side long member (2), a front cross member (3) and a rear cross member (4) which are joined and formed as a frame having 4 pivot points each one is arranged at the centre of the members,
wherein the articulated suspension (S) comprised of a ‘C’ shaped arm LH (5) provided with pivot pin (5a), a ‘C’ shaped arm RH (6) provided with pivot pin (6a), a rocker arm assembly LH (7) having pivot pin (7a) a rocker arm assembly RH (8) having pivot pin (8a),
wherein the ‘C’ shaped arm LH (5) the ‘C’ shaped arm RH (6) are inter linked by the rocker arm assembly LH (7) and the rocker assembly RH (8),
wherein the articulated suspension system (S) is pivotally supported at pivot points (PP1,PP2,PP3 and PP4) of the floating frame (F) by the pivot pins (P1, P2,P3 and P4),
wherein the transmission arrangement comprising an engine (9) which transmits power via a transmission arrangement (10) to a gear box (11) that transmits drive to a differential (12),
wherein the differential (12) split the drive into LH side drive & RH drive and the transmitted to a power split gear box LH (13) and to a power split gear box RH (14),
wherein the power is transmitted to a front reduction hub gear box LH (17), rear reduction hub gear box LH (18) and to respective wheels attached to them through power split gear box LH (13), angle gear front LH (15) and angle gear rear LH (16),
wherein the power is transmitted to a front reduction hub gear box RH (21) and a rear reduction hub gear box RH (22) and to respective wheels attached to them through power split gear box RH (14), angle gear front RH (19) and an angle gear rear RH (20), and
wherein the steering arrangement is a four wheel steering.

2. The multipurpose land vehicle with four wheel drive as claimed in claim 1, wherein the steering arrangement comprising a rack and pinion steering gear (23) comprising a rack LH (24) and a rack RH (25),
wherein the operation of the steering gear through the rack LH (24) and the rack RH (25) incorporates rotary motion to drive shaft LH (26) and the drive shaft RH (28),
wherein the rotary motion of the drive shaft LH (26) and the drive shaft RH (28) through the worm (29,29’,29’’,29’’’) and segment gears (30,30’,30’’,30’’’) that turn the wheels fitted to the respective reduction hub gear box (17,18,21,22).

3. The multipurpose land vehicle with four wheel drive as claimed in claim 1, comprises a hydrostatic pump (31) which pumps and supply hydraulic fluid to a steering valve (32) which is activated by the operation of the steering wheel,
wherein the steering valve (32) operates the hydrostatic motors (33,33’,33’’,33’’’) to incorporate rotary motion to the worms (29,29’,29’’,29’’’),
wherein the worm (29,29’,29’’,29’’’) are in drive engagement with the segment gears (30,30’,30’’,30’’’) respectively that turn the wheels fitted to the respective reduction hub gear box (17,18,21,22) to steer the vehicle.

4. The multipurpose land vehicle with four wheel drive as claimed in claim 1, wherein the transmission arrangement (10) is continuously variable transmission (CVT).

5. The multipurpose land vehicle with four wheel drive as claimed in claim 1, wherein the reduction hub gear box LH (17), the rear reduction hub gear box LH (18), the reduction hub gear box RH (21) and the rear reduction hub gear box RH (22) which are mounted on the wheel of the vehicle are heavy duty reduction gear box of higher weight with high reduction ratio.

6. The multipurpose land vehicle with four wheel drive as claimed in claim 1, wherein the power split gear box LH (13), the angle gear front LH (15), the angle gear rear LH (16), the power split gear box RH (14), the angle gear front RH (19) and the angle gear rear RH (20) which are mounted on the floating frame (F) are light duty gear boxes of lighter weight with low reduction ratio.