Claims:WE CLAIM:
1. A handlebar assembly (100) comprising:
a centre tube (110) coupled to a steering shaft (20) of a vehicle (10), the centre tube (110) extends in a vehicle width direction (W) between a left end (110L) and a right end (110R);
a left side tube (120L) having a proximal end (122L) and a distal end (124L), the proximal end (122L) having a flared portion (130L) configured to be inserted into the left end (110L) of the centre tube (110); and
a right side tube (120R) having a proximal end (122R) and a distal end (124R), the proximal end (122R) having a flared portion (130R) configured to be inserted into the right end (110R) of the centre tube (110).

2. The handlebar assembly (100) as claimed in claim 1, wherein the centre tube (110), the left side tube (120L), the right side tube (120R), the flared portion (130L) of the left side tube (120L) and the flared portion (130R) of the right side tube (120R) have a circular cross section.

3. The handlebar assembly (100) as claimed in claim 2, wherein the flared portion (130L) of the left side tube (120L) is disposed concentrically to the centre tube (110) at its left end (110L); and the flared portion (130R) of the right side tube (120R) is disposed concentrically to the centre tube (110) at its right end (110R).

4. The handlebar assembly (100) as claimed in claim 2, wherein an inner diameter (D) of the centre tube (110) is greater than an outer diameter (d1) of the of the left side tube (120L) and the right side tube (120R).

5. The handlebar assembly (100) as claimed in claim 4, wherein an outer diameter (d2) of the flared portion (130L) of the left side tube (120L) and the flared portion (130R) of the right side tube (120R) is lesser than the inner diameter (D) of the centre tube (110).

6. The handlebar assembly (100) as claimed in claim 4, wherein an outer diameter (d2) of the flared portion (130L) of the left side tube (120L) and the flared portion (130R) of the right side tube (120R) is substantially equal to the inner diameter (D) of the centre tube (110).

7. The handlebar assembly (100) as claimed in claim 1, wherein: the left side tube (120L) gradually expands to define a flaring transition section (132L) and the flared portion (130L), the flared portion (130L) extends from the flaring transition section (132L); and the right side tube (120R) gradually expands to define a flaring transition section (132R) and the flared portion (130R), the flared portion (130R) extends from the flaring transition section (132R).

8. The handlebar assembly (100) as claimed in claim 1, wherein: the proximal end (122L) of the left side tube (120L) is welded to the left end (110L) of the centre tube (110); and the proximal end (122R) of the right side tube (120R) is welded to the right end (110R) of the centre tube (110).

9. The handlebar assembly (100) as claimed in claim 1 comprising a pair of handlebar holders (160) mounted on an upper bridge (24), the upper bridge (24) being coupled to the steering shaft (20) and connecting a pair of front forks (22) of the vehicle (10), wherein the pair of handlebar holders (160) is configured to receive the centre tube (110).

10. The handlebar assembly (100) as claimed in claim 1, comprising a handlebar grip (140), a lever (142) and switchgear (144) disposed at the distal end (124L) of the left side tube (120L) and at the distal end (124R) of the right side tube (120R).
, Description:FIELD OF THE INVENTION
[001] The present invention generally relates to a handlebar assembly and particularly relates to assembly of components of the handlebar assembly.

BACKGROUND OF THE INVENTION
[002] Handlebars have been conventionally used to steer two-wheeled vehicles that entail an element of balancing while in motion. Hence, the handlebar has been employed in motorcycles, scooters and cycles to balance and steer them. Handlebars are also cheaper alternative to steering wheels and hence have been employed in a wide variety of vehicles including three-wheeled vehicles, light ATVs, light work machines, etc. Additionally, handlebars provide mounting platform for switches or levers of controls such as brakes, throttle, clutch, horn, lights, etc. and for other accessories like rear view mirrors. Since an operator’s hands rest on the handlebar while the vehicle is in use, locating control switches of the vehicle on the handlebar is convenient and saves space on the vehicle’s body.
[003] Generally, the handlebar is made from a single tube of uniform circular cross section bent into desired shape. This simplistic design allows for ease of manufacture and lower costs. However, the handlebar is to have adequate strength and stiffness and should be sturdy enough to resist deformations and deflections. The handlebar is most prone to deformation and deflection around its mounting zones, i.e., around region of the handlebar where it is mounted to handlebar holders. Deformation of the handlebar or deflections at the mounting zones can occur when the operator constantly puts his/her weight on the handlebar owing to the riding position, while manoeuvring or under breaking and due to stresses in the handlebar from road undulations or obstructions. Deflections and deformations are a safety concern as they affect the steerability and handling of the vehicle and may lead to loss of control and accidents.
[004] A solution to increase the strength of the handlebar is to provide for a tube having higher section modulus, at least near its mounting zones. Higher section modulus can be achieved by increasing the diameter of the tube. But increasing the cross sectional diameter of the tube along its entire length poses other challenges. A tube of larger diameter will be heavier and more costly. Furthermore, larger diameter of the tube at its distal ends would affect ergonomics adversely as handlebar grips have to be that much wider and vehicle switchgear have to be placed distant from one another causing discomfort to operator. Another solution is to shape ductile metals such as aluminium, brass, low alloy steel, or stainless steel into lightweight, structurally stiff and strong tubes for use in handlebars through the process of hydroforming. However, this process of forming such tubes is very expensive.
[005] Another alternative is to employ split handlebars. Instead of using a single tube of uniform cross section, split handlebars use multiple tubes of varying cross sections connected together to form the handlebar. A tube with higher section modulus, i.e., a larger cross sectional diameter is used at the mounting zones of the handlebar and narrower tubes are used at sides of the vehicle where the handlebar grips and the controls are mounted, to ensure good ergonomics. This arrangement ensures adequate strength at the mounting zones while keeping weight of the handlebar in check. Multiple tubes of varying cross sections are joined together in split type handlebars via welding. Welding of tubes of different cross sections is complex and requires the use of sophisticated guiding tools, dedicated welding machinery and highly skilled workforce. The use of sophisticated guiding tools and machinery and employing ultra-skilled workforce drives up the manufacturing cost and could make vehicle production uneconomical. Further, if the tubes are not properly held against one another or there is a slight misjudgement in orientation, welding miss outs may occur leading to compromise in strength at welding zones. The handlebar may deform or even break at welding zones thereby increasing the probability of fatal accidents. Therefore, it is desirable to have a split type handlebar with enough rigidity to avoid deflection under normal loads and road stresses at minimum manufacturing and material costs.
[006] Thus, there is a need in the art for a handlebar assembly, which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[007] In one aspect, the present invention is directed to a handlebar assembly. The handlebar assembly includes a centre tube, a left side tube and a right side tube. The centre tube is coupled to a steering shaft of a vehicle and extends in a vehicle width direction between a left end and a right end. The left side tube has a proximal end and a distal end. The proximal end of the left side tube has a flared portion adapted to be inserted into the left end of the centre tube. The right side tube has a proximal end and a distal end. The proximal end of the right side tube has a flared portion adapted to be inserted into the right end of the centre tube.
[008] In an embodiment, the centre tube, the left side tube, the right side tube, the flared portion of the left side tube and the flared portion of the right side tube are of a circular cross section. In another embodiment, the flared portion of the left side tube is disposed concentrically to the centre tube at its left end and the flared portion of the right side tube is disposed concentrically to the centre tube at its right end in an assembled state of the handlebar assembly.
[009] In a further embodiment, an inner diameter of the centre tube is greater than an outer diameter of the of the left side tube and the right side tube, the outer diameter of the left side tube and the right side tube being the same. In another embodiment, an outer diameter of the flared portion of the left side tube and the flared portion of the right side tube is lesser than the inner diameter of the centre tube. In yet another embodiment, the outer diameter of the flared portions of the left side tube and the right side tube is substantially equal to the inner diameter of the centre tube.
[010] In an embodiment, the left side tube gradually expands to define a flaring transition section and the flared portion of the left side tube, such that the flared portion extends from the flaring transition section. The right side tube gradually expands to define a flaring transition section and the flared portion of the right side tube, such that the flared portion extends from the flaring transition section.
[011] In a further embodiment, the proximal end of the left side tube is welded to the left end of the centre tube, and the proximal end of the right side tube is welded to the right end of the centre tube.
[012] In an embodiment, the handlebar assembly includes a pair of handlebar holders mounted on an upper bridge disposed at a top portion of a front suspension of the vehicle. The upper bridge is coupled to the steering shaft and connects a pair of front forks of the vehicle. The pair of handlebar holders is configured to receive the centre tube.
[013] In yet another embodiment, a handlebar grip, a lever for brake/clutch and switchgear are disposed at the distal end of the left side tube and at the distal end of the right side tube.

BRIEF DESCRIPTION OF THE DRAWINGS
[014] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a schematic side elevation view of an exemplary vehicle, in accordance with an embodiment of the present invention.
Figure 2 illustrates a perspective view of a front portion of the vehicle, in accordance with an embodiment of the present invention.
Figure 3 illustrates a perspective view of the front portion of the vehicle, in accordance with an embodiment of the present invention.
Figure 4 illustrates a perspective view of an exemplary handlebar assembly and an upper bridge assembly of the vehicle, in accordance with an embodiment of the present invention.
Figure 5 illustrates a rear elevation view of the handlebar assembly, in accordance with an embodiment of the present invention.
Figure 6 illustrates a cross sectional view of the handlebar assembly, in accordance with an embodiment of the present invention.
Figure 7 illustrates a cross sectional view of the handlebar assembly, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[015] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[016] The present invention generally relates to a handlebar assembly and particularly relates to assembly of components of the handlebar assembly. In the ensuing exemplary embodiments, the vehicle 10 is a two-wheeled vehicle. However, it is contemplated that the disclosure in the present invention may be applied to any automobile like a three-wheeled or four-wheeled vehicle capable of accommodating the present subject matter without defeating the scope of the present invention.
[017] Figure 1 illustrates a schematic side elevation view of an exemplary vehicle 10, in accordance with an embodiment of the present subject matter. The vehicle 10 comprises a front wheel 36, a rear wheel 38, a frame member (not shown) and a seat 44. The frame member includes a head pipe 18, a main tube (not shown), a down tube (not shown), and seat rails (not shown). A headlamp 32 and an instrument cluster (not shown) are arranged on an upper portion of the head pipe 18. Further, the head pipe 18 supports a steering shaft 20 (shown in Figure 2) disposed inside the head pipe 18. A front suspension 22 coupled to the steering shaft 20 is provided at a front of the vehicle 10, the front wheel 36 being supported by the front suspension 22. In the illustrated embodiment, the front suspension 22 is a fork type suspension, i.e., a pair of front forks 22. An upper portion of the front wheel 36 is covered by a front fender 46 mounted to a lower portion of the pair of front forks 22. A handlebar assembly 100 is operatively coupled to the steering shaft 20 and can rotate about the head pipe 18 for steering the vehicle 10.
[018] The vehicle 10 includes a prime mover 12 that is adapted to provide motive force for movement of the vehicle 10. In an embodiment, the prime mover 12 is an internal combustion engine. A fuel tank 42 is mounted on the main tube. An exhaust pipe (not shown) extends vertically downward from the prime mover 12 and then extends below the prime mover 12, longitudinally along length of the vehicle 10 before terminating in a muffler (not shown). In another embodiment, the prime mover 12 is an electric motor. The down tube is positioned in front of the prime mover 12 and extends downward from the head pipe 18 in a slanting manner. The main tube of the frame member is located above the prime mover 12 and extends rearward from the head pipe 18. Seat rails are joined to the main tube and extend rearward to support the seat 44. A rear swing arm (not shown) is connected to the frame member to swing vertically, and a rear wheel 38 is connected to a rear end of the rear swing arm. The rear swing arm is supported by a rear suspension 52. A taillight 54 is disposed at a rear of the seat assembly 44. A grab rail 56 is also provided to the seat rails. The rear wheel 38 arranged below the seat 44 rotates by motive force generated by the prime mover 12 transmitted through a transmission (not shown). A rear fender 48 is disposed above the rear wheel 38.
[019] Figures 2 and 3 illustrate perspective views of a front portion of the vehicle 10, in accordance with an embodiment of the present subject matter. An upper bridge 24 is disposed at a top portion of the pair of front forks 22 and connects the pair of front forks 22. The upper bridge 24 is also coupled to the steering shaft 20, such that by rotating the upper bridge 24 the steering shaft 20 turns along with the pair of front forks 22 allowing the front wheel 36 to turn in the same direction. A lower bridge 26 is disposed downwardly of the upper bridge 24 and at a lower portion of the head pipe 18. The lower bridge 26 connects the head pipe 18 and the pair of front forks 22.
[020] In an embodiment, a pair of handlebar holders 160 are mounted on the upper bridge 24. The pair of handlebar holders 160 are adapted to receive the handlebar assembly 100. The handlebar assembly 100 is secured to the pair of handlebar holders 160 with the aid of handlebar clamps 162. Hence, rotation of the handlebar assembly 100 is translated to rotation of the upper bridge 24 to steer the vehicle 10. In another embodiment, handlebar grips 140 are mounted on the left and right ends of the handlebar assembly 100. An operator rests his/her palms and holds the handlebar assembly 100 at the handlebar grips 140 while operating the vehicle 10. The handlebar grips 140 offer enough friction for the operator to hold on to the handlebar assembly 100 in comfort while the vehicle 10 is in motion.
[021] In a further embodiment, switchgear 144 and levers 142 for controls of the vehicle 10 are mounted on the handlebar assembly 100. The switchgear 144 and levers 142 for controls of the vehicle 10 are disposed close to the handlebar grips 140 to be easily accessible to the operator without taking his/her hands off the handlebar assembly 100. In an embodiment, the levers 142 are mounted on the handlebar assembly 100. The levers 142 are adapted to control at least one of a front brake or a rear brake and a clutch of the vehicle 10. In another embodiment, the switchgear 144 is mounted on both left and right sides of the handlebar assembly 100. In an embodiment, the switchgear 144 on right side of the handlebar assembly 100 include a kill switch to turn off the vehicle 10, an ignition switch for starting the vehicle 10 and a switch to control the headlamp 32. In another embodiment, the switchgear 144 on left side of the handlebar assembly 100 include a switch to operate a horn, a switch to operate a pair of left and right turn signal lamps, switches for media controls and a switch to shift between a low beam and a high beam of the headlamp 32.
[022] In yet another embodiment, a brake fluid reservoir 148 to store brake fluid for a front brake of the vehicle 10 is mounted on the handlebar assembly 100. In another embodiment, handlebar end weights 146 are disposed on either end of the handlebar assembly 100 to enhance the aesthetic appeal of the handlebar assembly 100 and reduce vibrations in the handlebar assembly 100. In another embodiment, a pair of rear view mirrors 34 (shown in Figure 1) are mounted on either end of the handlebar assembly 100 to facilitate an operator to see rearward of the vehicle 10 without turning around.
[023] Figure 4 illustrates a perspective view of an exemplary handlebar assembly 100 and an upper bridge 24 of the vehicle 10, in accordance with an embodiment of the present subject matter. The handlebar assembly 100 includes a centre tube 110 extending in a vehicle width direction W (shown in Figure 3) between a left end 110L and a right end 110R. The centre tube 110 is received by the pair of handlebar holders 160. In assembled condition, the centre tube 110 is sandwiched between each of the pair of handlebar holders 160 and the corresponding handlebar clamp 162. Thus, the centre tube 110 is coupled to the steering shaft 20 and the vehicle 10 can be steered by rotating the centre tube 110 of the handlebar assembly 100. The handlebar assembly 100 includes a left side tube 120L and a right side tube 120R. In an embodiment, the centre tube 110, the left side tube 120L and the right side tube 120R have a circular cross section. In another embodiment, the centre tube 110, the left side tube 120L and the right side tube 120R are hollow tubes. In yet another embodiment, the left side tube 120L and the right side tube 120R have the same diameter. In a further embodiment, the inner diameter D (shown in Figures 6 and 7) of the centre tube 110 is greater than the outer diameter d1 (shown in Figures 6 and 7) of the left side tube 120L and the right side tube 120R. The left side tube 120L has a proximal end 122L adapted to be inserted into the centre tube 110 at its left end 110L. The right side tube 120R has a proximal end 122R adapted to be inserted into the centre tube 110 at its right end 110R.
[024] Hence, the handlebar assembly 100 is formed by joining the left side tube 120L to a left side 110L of the centre tube 110 and by joining the right side tube 120R to a right end 110R of the centre tube 110. In an embodiment, the left side tube 120L and the right side tube 120R are respectively secured to the centre tube 110 by welding. The proximal end 122L of the left side tube 120L is welded to the left end 110L of the centre tube 110 and the proximal end 122R of the right side tube 120R is welded to the right end 110R of the centre tube 110. In another embodiment, the handlebar grip 140, the lever 142 and the switchgear 144 are mounted to the left side tube 120L and the right side tube 120R respectively.
[025] Figure 5 illustrates a rear elevation view of the handlebar assembly 100, in accordance with an embodiment of the present subject matter. In an embodiment, the centre tube 110 includes a pair of mounting sections 112 adapted to be received by the pair of handlebar holders 160. In an embodiment, the pair of mounting sections 112 includes a knurled surface at contact interface between the centre tube 110 and the pair of handlebar holders 160 and between the centre tube 110 and the corresponding handlebar clamp 162. The knurled surface ensures adequate friction and prevents the centre tube 110 from slipping out of the pair of handlebar holders 160. In another embodiment, the left side tube 120L includes a distal end 124L opposite its proximal end 122L and the right side tube 120R includes a distal end 124R opposite its proximal end 122R. In an embodiment, the handlebar grip 140, the lever 142, the switchgear 144 the handlebar end weights 146 and the pair of rear view mirrors 34 are mounted at the distal end 124L of the left side tube 120L and the distal end 124R of the right side tube 120R respectively.
[026] In an embodiment, the proximal end 122L of the left side tube 120L includes a flared portion 130L (also shown in Figures 6 and 7). The flared portion 130L is adapted to be inserted into the left end 110L of the centre tube 110. The proximal end 122R of the right side tube 120R includes a flared portion 130R. The flared portion 130R is adapted to be inserted into the right end 110R of the centre tube 110. In an embodiment, the left side tube 120L gradually expands to define a flaring transition section 132L and the flared portion 130L. The flared portion 130L extends from the flaring transition section 132L such that the flaring transition section 132L is disposed between the flared portion 130L and the non-flared portion of the left side tube 120L. Further, the right side tube 120R gradually expands to define a flaring transition section 132R and the flared portion 130R. The flared portion 130R extends from the flaring transition section 132R such that the flaring transition section 132R is disposed between the flared portion 130R and the non-flared portion of the right side tube 120R.
[027] Figure 6 illustrates a cross sectional view of the handlebar assembly 100, in accordance with an embodiment of the present subject matter. While Figure 6 illustrates the cross sectional view of a left side of the handlebar assembly 100, the right side of the handlebar assembly 100 is a mirror image of the illustration in Figure 6. In an embodiment, the flared portions 130L, 130R of the left side tube 120L and the right side tube 120R have a circular cross section. In another embodiment, the flared portion 130L of the left side tube 120L is disposed concentrically to the centre tube 110 at its left end 110L and the flared portion 130R of the right side tube 120R is disposed concentrically to the centre tube 110 at its right end 110R. Outer surface of the flared portions 130L, 130R are parallel to inner surface of the centre tube 110 at its left end 110L and its right end 110R respectively. Concentricity of the flared portions 130L, 130R with the centre tube 110 aids in maintaining a uniform root gap between the flared portions 130L, 130R and the centre tube 110 during welding. This helps in avoiding welding miss outs while welding the left side tube 120L and the right side tube 120R respectively to the centre tube 110.
[028] In another embodiment, an outer diameter d2 of the flared portions 130L, 130R is lesser than the inner diameter D of the centre tube 110. Thus, there is a gap between the flared portions 130L, 130R and the centre tube 110 when assembled. This gap is adapted by varying the outer diameter d2 of the flared portions 130L, 130R to maintain adequate root gap for obtaining best weld efficacy. This gap also aids in uniform heat input and weld accessibility, i.e., easy reach of weld torch during welding process. In yet another embodiment, the outer diameter d2 of the flared portions 130L, 130R is substantially equal to the inner diameter D of the centre tube 110. This ensures that there is a tight fit between the flared portions 130L, 130R and the centre tube 110 on assembly. Thus, during assembly process the left side tube 120L and the right side tube 120R can be inserted into the centre tube 110 and can be held in place by the tight fit between the flared portions 130L, 130R and the centre tube. This automatically locates the left side tube 120L and the right side tube 120R for welding with the centre tube 110. Hence, use of sophisticated guiding tools, dedicated welding machinery and highly skilled workforce can be dispensed with leading to reduced manufacturing cost.
[029] Figure 7 illustrates a cross sectional view of the handlebar assembly 100, in accordance with an embodiment of the present subject matter. While Figure 7 illustrates the cross sectional view of a left side of the handlebar assembly 100, the right side of the handlebar assembly 100 is a mirror image of the illustration in Figure 7. In an embodiment, welding technique employed to weld the proximal end 122L of the left side tube 120L to the left end 110L of the centre tube 110 and the proximal end 122R of the right side tube 120R to the right end 110R of the centre tube 110 is lap welding. The weld 115 is provided along circumference of a periphery between the left side tube 120L and the centre tube 110, and the right side tube 120R and the centre tube 110 respectively. In an embodiment, the continuous weld 115 ensures that there is no steep junction between the centre tube 110 and the left side tube 120L, and the centre tube 110 and the right side tube 120R at their respective joining interfaces. Thus, a smooth and aesthetically appealing joint between the centre tube 110, the left side tube 120L and the right side tube 120R can be obtained. Lap welding has a measurable advantage over butt welding in terms of weld quality and ease of welding when tubes of different cross sections are welded together. Insertion of the flared portions 130L, 130R into the centre tube 110 along with lap welded joints make the junction between the left side tube 120L and the right side tube 120R and the centre tube 110 resilient to forces applied by the operator and other road stresses. In a further embodiment, the flaring transition sections 132L, 132R can act as locators to identify how much of the flared portions 130L, 130R have to be inserted into the left end 110L and the right end 110R respectively of the centre tube 110. Hence, complex locator systems and machines can be dispensed with during assembly process.
[030] Advantageously, the present invention provides a handlebar assembly 100 and disposition of components of the handlebar assembly 100. Since the handlebar assembly 100 is mechanically connected to the vehicle 10 only through the centre tube 110, only the diameter of the centre tube 110 need to be increased to enhance the strength and rigidity of the handlebar assembly. Thus, the handlebar assembly 100 is stronger at the mounting zones 112 and resists deformation and deflection effectively under external loads. Further, the cross sectional size of the centre tube 110 can be increased without affecting the diameter d1 of the left side tube 120L and the right side tube 120R owing to the provision of flared portions 130L, 130R. Hence, operator ergonomics and switchgear placement will remain unaffected while the strength and durability of the handlebar assembly 100 is enhanced. Further, preservation of consistent root gap between the centre tube 110 and the right side tube 120R and the left side tube 120L respectively during welding avoids welding miss outs. Additionally, the use of sophisticated guiding tools, dedicated welding machinery and highly skilled workforce can be dispensed with. The handlebar assembly 100 also provides for increased durability, better manufacturability, enhanced aesthetics, better safety and weight and cost reduction.
[031] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.