1 Mufti-axle vehicle configuration having heavy duty lift axle
FIELD OF INVENTION
[001] The present invention relates to a commercial vehicle configuration, and more particularly to a commercial multi-axle vehicle configuration having twin front axles, tandem leaf spring rear suspension and a heavy duty pusher lift axle having dual tires.
BACKGROUND OF INVENTION
[002] All countries have regulations which regulate the size and weight of the vehicles traveling on the road. The regulations vary from country to country, but basically they limit the amount of load per axle. Therefore, in all countries, the maximum loads that can be carried by a truck, as well as the maximum load that can be acted on each tire are limited. In addition, the maximum length of the vehicle that can be developed is also limited according to the road way design of the countries. Therefore, each country frames their own law for developing vehicles.
[003] In developing countries such as India and Pakistan etc., the load acting on the front steer axle (having single tire on each side) is limited to 6-7T. Similarly, the load acting on the rear non-steer axle (having dual tires on each side) is limited to 9.5-11.5T. Similarly, the load acting on the auxiliary lift axles is also legally limited. The load capacity of the auxiliary lift axle having single tire on each side is limited to 6-7Tand the auxiliary lift axle having dual tires on each side is limited to about 10.2-11.5T.The limitation of load acting on the axle is important, because, it is designed to prevent the damage of road due to excessive and concentrated pressures thereon. On the other hand, from the

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truckers' viewpoint, it is desirable to be able to transport the maximum allowable load with using the economical and inexpensive vehicle.
[004] Now a day, original equipments manufacturers (OEMs) develop commercial multi-axle vehicles (having multi-axles) to satisfy customers demand. As cost of driver is being increased and road system is being improved, OEMs are more focusing on developing long commercial multi-axle vehicles (i.e., heavy duty rigid trucks) having maximum allowable load limit. At the same time, they focus on developing low cost and low maintenance vehicles.
[005] In order to increase the hauling capacity of the commercial multi-axle vehicle, auxiliary axles are added either in front of the drive axle or rear side of the drive axle. The auxiliary axle is usually an air suspension system. The axle can be lifted in un-laden condition. Therefore, it is called lift axle. If the auxiliary axle is located in-front of the drive axle, it is called as pusher lift axle. If the auxiliary axle is located at the rear side of the drive axle, it is called as tag lift axle.
[006] Figure 1 is a prior art of a commercial multi-axle vehicle (CMV) having configuration of 10x4 with a pusher lift axle (1). Similarly, commercial multi-axle vehicle having configuration of 10x4 with a tag lift axle (not shown) is being developed. Such vehicles are manufactured in developed countries such as USA and Australia. The vehicle has twin front axles (2a and 2b) and two rear axles (3a, 3b). The rear axles (3) are drive axles (3a and 3b). Another auxiliary axle is a lift axle (1). Therefore, the commercial multi-axle vehicle (i.e., heavy duty rigid trucks) is configured as 10x4 (i.e., 5 axles vehicles in which two of them are drive axles (3a and 3b) attached to rear side of the chassis frame). The twin front axles (2a and 2b) are equipped with leaf spring suspension system and the rear axles (3) are equipped with air spring suspension systems. The auxiliary axle is located in either pusher location (i.e.,

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in front of first drive axle, 3a) or tag location (i.e., rear side of second drive axle, 3b).
[007] Due to limited space available at the front of the vehicle, the front axles (first front axle (2a) and second front axle (2b)) are usually equipped with conventional leaf spring suspension systems. The suspension has appropriate spring stiffness to have a better ride and comport. The rear axles (3a and 3b) are equipped with air suspensions. The road condition of such developed countries (USA and Australia) is better than that compared to the developing countries such as India, Pakistan, China and Brazil, etc.,. Therefore, the rear air suspensions offers a better ride and comport compared to mechanical suspension (i.e., steel spring suspension). Further, the chassis can be lifted and lowered when loading or unloading the vehicle. In addition, ride height of the vehicle can be raised when the vehicle is operated in undulated roads. Furthermore, the ride height of the vehicle can be maintained a constant height in laden and unladen condition.
[008] Because of their adaptability, vehicles that are equipped with air spring suspension systems can be driven over a variety of terrains while maintaining a smoother ride and better handling. This is' achieved because an air spring works on a closed volume of compressed air at a desired pressure. Therefore, it gives to the driver a greater feel when the vehicle is operated on the road. In addition, the rear air spring suspensions improve handling and provide the ability to adjust for load/ weights (of commercial multi-axle vehicles). Moreover, the rear air suspension maintains a good tire contact (with road surface). Therefore, tire wear is also reduced if the commercial multi-axle vehicle is operated in rated load condition. Thus, the air suspension system will save money in the long run as less expenditure (i.e., spend) for tires, as well as other components such as axles and tie-rods. The smoother ride offered by air spring also will result in a steady, constant aim of the headlights, further improving safety. In addition, as the air suspension is manufactured largely in such

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developed countries, the cost of the air suspension is less compared to that of leaf spring suspension that is usually used in tipper (dump truck) vehicle only. In addition, the air spring suspension offers light weight, better fuel efficiency and low cost (i.e., vehicle's production cost). Moreover, air spring suspension offers low operating cost of the vehicle due to less maintenance (i.e., overall vehicle maintenance). Therefore, in developing countries such as USA, UK, Australia, Germany etc., and OEMs develop commercial multi-axle vehicle(i.e., heavy duty rigid trucks) having rear air suspension.
[009] In developing countries such as India, Pakistan, Brazil etc., the heavy commercial multi-axle vehicles are equipped with a steel suspension system, (i.e., composed of leaf springs). The leaf spring suspension is commonly used in truck in developing countries; because of its robustness and simple to manufacture. It is very complaint in vertical direction, laterally rigid and capable of carrying heavy loads. However, the leaf springs generally have greater weight than other type of springs such as air spring and coil spring with equivalent weight carrying capabilities.
[010] In terms of function, leaf spring suspensions are much simpler, since the axle is suspended by the leaf spring, and does not require the complicated suspension geometry. Leaf springs are much stronger, and are capable of handling much higher loads with less deflection than air springs. In addition, in developing countries the trucks are abused (over loaded) and are operated in undulated roads. Moreover, the load is arranged an un-organized manor in the load body, which results an increase in the thrust angle in the rear axles. It leads a sever tire wear in the tires. Therefore, additional leafs are added to the conventional leaf spring suspension which is according the application requirements. In addition, the same heavy truck is used for multi-purpose applications (i.e., (a) carrying light density materials such as parcel, general goods, wood, etc., and (b) carrying heavy density materials such as machinery, sand, steel coil, oil&gas, etc.).In order to carry heavy loads in the undulated

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road, truck users in developing countries prefer truck having rear leaf spring suspension.
[Oil] Figure 2 is prior arts of tandem rear leaf spring suspensions (4); (a) non-reactive suspension (4a) , b) slipper end balancer beam suspension (4b) and c) bogie inverted leaf spring suspension (4c).These suspensions are commercially accepted in multi-axle vehicles operated in developing countries. The non-reactive suspension (4a, Figure 2a) and the slipper end balancer beam suspension (4b, Figure2 b) are used in the MAV operated for haulage application; because of its low cost. Whereas, bogie inverted leaf spring suspension (4c, Figure2c), (has a moderate cost and a higher self weight) is commercially accepted for the multi-axle vehicle (i.e., commercial multi-axle vehicle) operated for tipper application.
[012] The conventional available rear air suspension vehicle is designed for rated load application. The suspension and chassis frame of the vehicle are designed to light weight to withstand rated loads. Few OEMs tried to use this air suspension in developing countries such as in India. However, the trailing arm type air suspension having dual tire is not yet commercially accepted because of its low ground clearance and reversible sleeve air spring, etc. In addition, few trailer manufactures tried to use this air suspension. A lot of failures are observed in the truck (having rear air suspension) operated in undulated roads. A frequent failure is observed in the rubber bushing used in the control arms of air suspension. It is mainly due the sever fatigue load experienced in the pivot joins. A sever bend is observed in the Panhard rod which is due to severe cornering load. As the air suspension experiences frequent undulates, the air springs consume a large amount of compressed air. Therefore, a big compressor (with higher capacity of air tanks) is required. In addition, it consumes a considerable power from engine; therefore, a less fuel efficiently is observed in the trucks having rear air suspension. In addition, cost of the air suspension and maintenance cost (if vehicle is operated in

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undulated road) are remarkably high in the developing countries. From the overall study, the conventional available commercial multi-axle vehicle (i.e., heavy duty rigid truck) having rear air suspension (Figure 1, prior art) is not desirable solution for hauling in developing countries. Therefore, a new commercial multi-axle vehicle is required, which should give high performance in the undulated road and abused condition (rugged operating condition). In addition, it should be economical for both OEM (i.e., low over all production cost) and user (i.e., less investment, operating and maintenance cost).
[013] Accordingly, the present invention provides two improved commercial multi-axle vehicle configurations of the prior arts which meets the legal requirements of developing countries and provides the desirable advantages and objects referred to. More specially, the present invention provides a heavy duty multi-axle rigid truck having a pusher lift axle having dual tires and tandem rear spring suspension.
OBJECT OF THE INVENTION
[014] Prime object of the present invention is to provide commercial multi-axle vehicles (having maximum legally allowable load carrying capacity) in both 10x2 and 10x4 configurations for developing countries
[015] Another object of the present invention is to provide commercial multi-axle vehicles, which should be economical for both OEMs (i.e., low over all production cost) and users (i.e., less investment, operating and maintenance cost).
[016] Another object of the present invention is to provide commercial multi-axle vehicles, which should be operated in rugged operation.
[017] Another object of the present invention is to provide commercial multi-axle vehicles, which should have a pusher lift axle.

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[018] Another object of the present invention is to provide commercial multi-axle vehicles, which should be used for haulage application.
[010] Yet another object of the present invention is to provide commercial multi-axle vehicles, which should have a non-steer lift axle having dual tires.
[020] Yet another object of the present invention is to provide commercial multi-axle vehicles, which should have a steer lift axle having dual tires as analternative option.
[021] Another object of the present invention is to provide commercial multi-axle vehicles, which should have more reliable in developing countries.
[022] Another object of the present invention is to provide commercial multi-axle vehicles, which should have hauling capacity of maximum legal limit in both 10x2 and 10x4 configuration vehicles.
[023] Another object of the present invention is to provide commercial multi-axle vehicles, which should have sufficient grade-ability.
[024] Another object of the present invention is to provide commercial multi-axle vehicles, which should be suitable for operating undulated roads.
[025] Another object of the present invention is to provide commercial multi-axle vehicles, which should have moderate technology suitable to developing countries.
[026] Another object of the present invention is to provide commercial multi-axle vehicles, which should consume less amount of air consumption.
[027] Another object of the present invention is to provide commercial multi-axle vehicles, which should have high fuel efficiency.
[028] Another object of the present invention is to provide commercial multi-axle vehicles, which should have less power engine.

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[029] Another object of the present invention is to provide commercial multi-axle vehicles, which should have less tire wear.
[030] Another object of the present invention is to provide commercial multi-axle vehicles, which should be suitable to multi-purpose applications.
[031] Yet another object of the present invention is to provide commercial multi-axle vehicles, which withstands dynamic loads and shocks.
SUMMARY OF THE INVENTION
[032] A low cost and high fuel efficiency commercial multi-axle vehicle configuration of 10x2 (5) (having heavy duty pusher lift axle) is disclosed for hauling application for developing countries as a first embodiment. The vehicle that can carry a maximum allowable load in undulated road has two front axles (6a and 6b), a pusher axle (8) and two rear axles (7a and 7b). The front axles (6a and 6b) and rear axles (7a and 7b) are equipped with conventional leaf spring suspension (4). The tandem rear suspension system (4) is either NRS leaf spring suspension (4a) or slipper end balancer bean leaf spring suspension (4b) or bogie inverted leaf spring suspension (4c). The pusher lift axle(8)(having dual tires (9) on each sidejis either non-steer air suspension (8a)or steer air suspension (8b). All the axles are mounted with the chassis frame (10) in the usual way. The front axles (6a and 6b)having single tire (11) on each side are steered by power steering. All the tandem rear axles (7a and 7b)having dual tires on each side are non-steer axles. The pusher lift axle (8) has dual tires (9) on each side. Therefore, the commercial multi-axle vehicle (i.e., heavy duty multi-axle rigid truck (5)) can carry maximum allowable load in developing countries, according to the first embodiment of the invention. It is a feature of this invention that the pusher lift axle (8) having dual tires (9) is mounted to the chassis frame (10) in front of single drive axle (7a). The driver cabin, load body, fuel tank and other accessories such as battery carries, air

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tank, muffler, exhaust, electrical etc., are attached with the chassis frame (1 l)in a well-known manner.
[033] A low cost and high fuel efficiency commercial multi-axle vehicle configuration of 10X4, 18) is disclosed for hauling application for developing countries as a second embodiment. It is a feature of this invention that the pusher lift axle (20) having dual tires (22) is mounted to the chassis frame (24) in front of dual drive axles (21a and 21b) equipped with the tandem leaf spring suspension (25). The other entire systems except two drive axles (21a and 21b) are similar to the first embodiment. The commercial multi-axle vehicle having configuration of 10X4 (18) is provided for better drivability in sever undulated roads.
BRIEF DESCRIPTION OF THE DRAWINGS
[034] The objects and advantages of the present invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings, in which:
[035] FIG.lillustrates the commercial multi-axle vehicle (10x4) having pusher lift axle and rear air suspension (prior arts) operated in developed countries such as USA,UK, Australia, etc.
[036] FIG.2 illustrates conventional tandem rear leaf spring suspensions (prior art) used in developing countries such as India, Brazil, Pakistan, etc.
[037] FIG.3illustrates commercial multi-axle vehicle (i.e., heavy duty multi-axle vehicles, MAV,)having pusher lift axle in the 10x2 vehicle configuration, in accordance with an exemplary first embodiment of the present invention.
[038] FIG.4 illustrates the suspension methodologies used, in accordance with the first embodiment of the present invention.

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[039] FIG.5illustrates a lift axle suspension, in accordance with an exemplary first embodiment of the present invention.
[040] FIG.6 illustrates the detail of dual tires lift axle suspension fitted with the tandem rear leaf spring suspensions, in accordance with an exemplary first embodiment of the present invention.
[041] FIG.7 illustrates a view of non-steer dual tire lift axle and steer lift axle suspension system, in accordance with an exemplary first embodiment of the present invention.
[042] FIG.8 illustrates commercial multi-axle vehicle, having pusher lift axle in the 10x4 vehicle configuration, in accordance with an exemplary second embodiment of the present invention.
[043] FIG.9 illustrates the suspension methodologies used, in accordance with the second embodiment of the present invention.
[044] FIG. 10 illustrates the details of dual tires lift axle suspension fitted with the tandem rear leaf spring suspensions, in accordance with an exemplary second embodiment of the present invention.
[045] FIG.l 1 illustrates a view of non-steer dual tire lift axle and steer lift axle suspension system, in accordance with an exemplary second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[046] Referring to FIG. 3 of the drawings, a commercial multi-axle vehicle (5), having configuration of 10X2, is disclosed for haulage application. The commercial multi-axle vehicle (5) has two front axles (6aand 6b), a pusher axle and two rear axles (7a and 7b). The front axles (6a and 6b) are, namely, first front axle (6a) and second front axle (6b). The rear axles (7a and 7b) are, namely drive axle (7a) and dummy axle (7b). It is a feature of this invention that the pusher lift axle (8) has dual tires (9). It is either non-steer air

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suspension or steer air suspension. The lift axle is located in front of the conventional tandem rear leaf spring suspension (4) in a well-known manner. All the axles (6a,6b, 7a, 7b and 8) are mounted with the chassis frame (9) in the usual way. The front axles (6a and 6b) are steered by power steering and all the tandem rear axles (7a and 7b) are non-steer axles. Each front axle has single tire (11) on each side. Similarly, each rear axle (7a and 7b) having dual tires (9) on each side. The pusher lift axle (8) having dual tires (9) on each side. Therefore, the present commercial multi-axle vehicle (5), can carry maximum allowable load in developing countries, according to the first embodiment of the invention. It is a feature of this invention that the pusher lift axle (8) having dual tires (11) is mounted in the chassis frame (10) in front of single drive axle (7a). The driver cabin, load body, fuel tank and other accessories such as battery carries, air tank, muffler, exhaust, electrical etc., are attached with the chassis frame (10) in a well-known manner.
[047] FIG.4 illustrates the details of the front axles (6a and 6b), pusher lift axle suspension (8)and tandem rear suspensions (7a and 7b), in accordance with first exemplary embodiment of the present invention. A pair of front axles namely, first front axle (6a) and second front axle (6b), are attached to the chassis frame (10) through the conventional multi-leaf spring suspension in a well-known conventional manner. The fuel tank is attached to the side member of the chassis frame (10) and is placed behind the second front axle (6a). The tandem rear non-steer axles (7a and 7b) equipped with conventional proven tandem leaf spring suspension (4) is attached at the rear end of the chassis frame (10) through suitable brackets in usual ways. According to the first embodiments of present invention, the tandem rear leaf spring suspension (4)is either NRS leaf spring suspension (4a, Figure 4a) or slipper end balancer beam suspension (4b, Figure 4b) or bogie inverted leaf spring suspension (4c, Figure 4a). The pusher lift axle (8) is an air suspension. It is attached to the chassis frame (10) in between the twin front axles (6a and 6b) and tandem rear axles (7a and 7b). The load body (12) is rigidly attached on the chassis frame(10)by

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mechanical means. The driver cabin (13) is pivotally attached at the front end of the chassis frame (10) which is above the engine assembly (not shown).
[048] FIG.5 illustrates the details of the pusher lift axle (8). It has a pair of load air springs (14), a pair of lift air springs (15), a pair of top control arms (16) and a pair of lower control arms (17). In addition, it has two tires at each side of the axle. The design of lift axle (8) is not a part of present invention. Therefore, the details are not described hereafter. In unladen condition, the load air spring (14) is deflated and lift air spring (15) are inflated. The axle is lifted-off from the road surface and is held at a desired height from the road surface.
[049] FIG.6 illustrates the details of the tandem rear suspension and the location of pusher lift axle (8). The tandem rear suspension is either equipped with NRS leaf spring suspension (4a, Figure 6a) or slipper end balancer beam suspension (4b, Figure 6b) or bogie inverted leaf spring suspension (4c, Figure 6c).The NRS leaf spring suspension (4a, Figure 6a), slipper end balancer beam suspension (4b, Figure 6b) and bogie inverted leaf spring suspension (4c, Figure 6c) are commercially accepted in developing countries. The design of leaf spring suspension is not a part of present invention. Therefore, the details are not described hereafter. According to the first embodiment of present invention, one of the tandem rear suspensions is a drive axle (7a)and another is a dummy axle (7b). It is mainly to develop a low cost, high fuel efficiency commercial multi-axle vehicle, according to objects of present invention.
[050] FIG.7 illustrates the top view of the tandem rear suspension (4) and the pusher lift axle (8). The pusher lift axle (8) has dual tires (9) at the each side of the axle. The pusher lift axle (8) is equipped with air spring suspension. According to the first embodiment of present invention is the pusher lift axle (8) is either non-steer suspension (8a, Figure 7a) or steer suspension (Figure 7b). The cost of the non-steer lift axle (8a) is less compared to that of steer suspension (8b, Figure 7b). In the performance aspect, the steer axle has a better tire life compared to that of non-steer lift axle (8a). Therefore, according

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to an object of present invention, a low cost commercial multi-axle vehicle is provided using the non-steer pusher lift axle (8a). In addition, a high performance (less tire wear) commercial multi-axle vehicle is also provided using the steer pusher lift axle(8a) according to another object of present invention.
[051] Referring to FIG. 8 of the drawings, a commercial multi-axle vehicle (18) (having configuration of 10X4) is disclosed for haulage application. The commercial multi-axle vehicle (18) has two front axles (19a and 19b), a pusher lift axle(20) and two rear axles(21a and 21b). The front axles are, namely, first front axle (19a)), and second front axle (19b). The rear axles are, namely first drive axle (21a), and second drive axle (21b). It is a feature of this invention that the pusher lift axle (20) has dual tires (22), It is either non-steer air suspension (20a) or steer air suspension (20b). The lift axle is located in front of the conventional tandem rear leaf spring suspension in a well-known manner. AH the axles are mounted with the chassis frame (24) in the usual way. The front axles (19a and 19b), are steered by power steering and all the tandem rear axles (21a and 21b), are non-steer axles. Each front axle has single'tire (23) on each side. Similarly, each rear axle has dual tires (22) on each side. The pusher lift axle has dual tires (22) on each side. Therefore, the present commercial multi-axle vehicle can carry maximum allowable load in developing countries, according to the second embodiment of the invention. It is a feature of this invention that the pusher lift axle (20) having dual tires (22) is mounted on the chassis frame (24) in front of dual rear drive axles (21a and 21b). The driver cabin, load body, fuel tank and other accessories such as battery carries, air tank, muffler, exhaust, electrical etc., are attached with the chassis frame in a well-known manner. This vehicle is provided to give a better drivability when a vehicle is operated a sever undulated road, in accordance with a exemplary objective of present invention

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[052] FIG.9 illustrates the details of the front axles, pusher lift axle suspension and tandem rear axles, in accordance with first exemplary embodiment of the present invention. A pair of front axles namely, first front axle (19a) and second front axle (19b), are attached to the chassis frame (24) through the conventional multi-leaf spring suspension in a well-known conventional manner. The fuel tank is attached to the side member of the frame and is placed behind the second front axle. The tandem rear non-steer axles equipped with conventional proven leaf spring suspension is attached at the rear end of the chassis frame through suitable brackets in usual ways. According to the second embodiments of present invention, the tandem rear leaf spring suspension is either NRS leaf spring suspension (25a, Figure 9a) or slipper end balancer beam suspension (25b, Figure 9b) or bogie inverted leaf spring suspension (25c, Figure 9c). The pusher lift axle (20) is an air suspension. It is attached to the chassis frame (24) in between the twin front axles (19a and 19b) and tandem rear axles (21a and 21b). The load body is rigidly attached on the chassis frame (24)by mechanical means. The driver cabin is pivotally attached at the front end of the chassis frame (24) which is above the engine assembly (not shown).
[053] FIG. 10 illustrates the details of the tandem rear suspension and the location of pusher lift axle (20). The tandem rear suspension is either equipped with NRS leaf spring suspension (25a, Figure 10a) or slipper end balancer beam suspension (25b, Figure 10b) or bogie inverted leaf spring suspension (25c, Figure 10c). The NRS leaf spring suspension (25a, Figure 6a), slipper end balancer beam suspension (Figure 10b) and bogie inverted leaf spring suspension (25c, Figure 10c) are commercially accepted in developing countries. The design of leaf spring suspension is not a part of present invention. Therefore, it not is described hereafter. According to the second embodiment of present invention, the tandem rear suspensions (25)has two drive axles (21a and 21b), namely first drive axle ( 21a) and second drive (21b) axle one It is mainly to develop a low cost, high performance (better drivability

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in undulated road) commercial multi-axle vehicle, according to objects of present invention.
[054] FIG. 11 illustrates the top view of the tandem rear suspension (25) and the pusher lift axle (20). The pusher lift axle has dual tires (22) at the each side of the axle. The pusher lift axle (20) is equipped with the air spring suspension. According to the second embodiment of present invention is the pusher lift axle (20) is either non-steer suspension (20a, Figure 10a) or steer suspension (20b, Figure 10b). The cost of the non-steer lift axle (20a) is less compared to that of steer suspension (Figure 10b). In the performance aspect, the steer axle has a better tire life compared to that of non-steer lift axle (20a). Therefore, according to an object of present invention, a low cost commercial multi-axle vehicle (18) is provided using the non-steer pusher lift axle (20a). In addition, a high performance (less tire wear) commercial multi-axle vehicle is also provided using the steer pusher lift axle (20b) according to an another object of present invention.
[055] With the present arrangement, including the long rigid truck frame has been provided which is capable of carrying the maximum allowable load and the vehicle can be controlled by the operator because of the rigid frame and the non-steerable lift axle's wheels.
[056] As previously indicated the commercial multi-axle vehicles (5 and 18) of the present invention are the non-steerable type, and with this arrangement the truck can be easily and more positively controlled. It results in an economically produced and efficient truck capable of carrying the maximum load allowable by the laws of the developing countries.
[057] An important feature of this invention is that the commercial multi-axle vehicle could be converted quickly from haulage load body to tipper load body. [058] In addition, the truck could be converted quickly to conventional truck

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without load body for carrying long containers which is usually carried by tractor trailer combination vehicle. In addition, even without the conversion, different materials can be carried in the open area of load body, provided the gross weight for the truck is not exceeded. For example, sand and wood could be carried in the load body. When the truck is being used as a container carrier, the load body can be dismantled from the chassis frame by conventional manner.
[059] A unique of the present invention is the load carrying capacity of the vehicle. The commercial multi-axle vehicles (5 and 18))are capable of carrying the maximum allowable load and the vehicles can be controlled by the operator because of the rigid frame with the proven arrangement of front and rear leaf spring suspensions.
[060] A unique of the present invention is the design of commercial multi-axle vehicle. The commercial multi-axle vehicle is designed to suitable to rugged operation. Both front and rear suspensions are proven systems that have low cost and proven record in developing countries.
[061] A unique of the present invention is the pusher lift axle (8) in the 10x2 configuration (5). The commercial multi-axle vehicle (5) having configuration of 10x2 has a pusher lift axle (20) having dual tires (22) at the each side of the axle.
[062] A unique of the present invention is the pusher lift axle (20) in the 10x4 configuration (18). The commercial multi-axle vehicle having configuration of 10x4 has a pusher lift axle (20b) having dual tires (22) at the each side of the axle.
[063] Another unique of the present invention is the pusher lift axle is either non-steer axle air suspension (8a, 20a) or steer axle air suspension (8a, 20a).

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[064] Another unique of the present invention is the selection suspensions and vehicle configuration to provide a low cost, less maintenance and high fuel efficient commercial multi-axle vehicle that has a capability of carry maximum allowable load in developing countries. The rear drive axle and tag axle are equipped with one of the proven tandem rear leaf spring suspensions (It is low cost, low maintenance, high durable suspension. In addition, it is commercially accepted in developing countries.
[065] Another unique of the present invention is the selection suspensions and vehicle configuration to provide a high performance (less tire wear and high drivability) commercial multi-axle vehicle that has a capability of carry maximum allowable load in developing countries. The pusher lift axle (8, 20) is either non-steer or steer air suspension. The steer suspension provides a high performance commercial multi-axle vehicle (CMV); thereby high fuel efficient CMV is provided according to an object of the present invention.
[066] The invention is not limited to the embodiments here in before described which may be varied in both construction and detail within the scope of the appended claims.

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WE CLAIM:
1. A multi-axle vehicle having 10x2 configuration, comprises:
a first front axle (6a) and a second front axle (6b) equipped with leaf
spring suspensions attached to front side of a chassis frame (10);
at least two rear axles (drive axle (7a) and dummy axle (7b)) equipped
with tandem leaf spring suspension attached to the rear side of the
chassis frame (10); and
a pusher lift axle (8) having dual tires (9), attached to the chassis
frame (10) in front of the rear drive axles (7a, 7b).
2. The multi-axle vehicle as claimed in claim 1, wherein said tandem leaf spring suspension attached to the rear side of chassis frame is either NRS leaf spring suspension (4a) or slipper end balancer beam leaf spring suspension (4b) or single point bogie inverted leaf spring suspension (4c).
3. The multi-axle vehicle as claimed in claim 1, wherein said pusher lift axle (8)having dual tires (9) attached in front of the tandem leaf spring suspension having single drive axle (7a) is either a non-steer air suspension (8a) or steer air suspension (8b).
4. The multi-axle vehicle as claimed in claim 3, wherein said the pusher lift axle (8) having dual tires (9) at each end is lifted in unladen condition automatically or manually.
5. The multi-axle vehicle as claimed in claim 2, wherein said NRS leaf spring suspension(4a), or slipper end balancer beam leaf spring suspension (4b) or single point bogie inverted leaf spring suspension (4c)is equipped with multi-leaf springs.
6. A multi-axle vehicle having 10x4 configuration, comprises:

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a first front axle (19a) and a second front axle(19b)equipped with leaf
spring suspensions attached to front side of a chassis frame (24);
at least two drive axles first drive axle (21a) and second drive axle (21b)
equipped with tandem leaf spring suspension (25) attached to rear side
of the chassis frame (24); and
a pusher lift axle (20) having dual tires (22), attached to the chassis
frame (24) in front of the rear drive axles (21a, 21b).
7. The multi-axle vehicle as claimed in claim 6, wherein said tandem leaf spring suspension (25) attached to the rear side of the chassis frame (24) is either NRS leaf spring suspension (25a) or slipper end balancer beam leaf spring suspension (25b) or single point bogie inverted leaf spring suspension (25c).
8. The multi-axle vehicle as claimed in claim 6, wherein said pusher lift axle (20) having dual tires (22)attached in front of the two rear drive axles (21a,21b) is either non-steer air suspension (20a) or steer air suspension (20b).
9. The multi-axle vehicle as claimed in claim 7, wherein said NRS leaf spring suspension (25a), or slipper end balancer beam leaf spring suspension (25b)or single point bogie inverted leaf spring suspension (25c)is equipped with multi-leaf springs.
10. The multi-axle vehicles claimed in claim 8, wherein said the
pusher lift axle (20) having dual tires (22) at each end is lifted in unladen
condition automatically or manually.
Dated this 27 day of July 2016
(RRNair)
Reg. No.: IN/PA- 121
Of De Penning & De Penning
Agent for the Applicants