TECHNICAL FIELD

[0001] The present subject matter generally relates to a transmission system for two and three wheeled vehicle, and particularly relates to a clutch manipulation system for the two and three wheeled vehicle clutch manipulation system.

BACKGROUND

[0002] A vehicle typically includes an internal combustion engine which imparts power to a transmission for driving the vehicle. The transmission has several gear ratios which an operator of the vehicle may put to use depending on the driving conditions. A clutch typically provides a mechanical coupling between the engine and transmission, and aids transfer of power and torque from the engine to the transmission by helping in shifting among various gear ratios. It coordinates smooth engagement of the spinning engine to the non-spinning transmission by controlling the slippage between them and hence allows the vehicle to stop without killing the engine.

[0003] The clutch can either be in engaged position or in disengaged position. When the clutch is engaged i.e. connected to a crankshaft of the engine, the transmission transfers a driving torque from the engine crankshaft to one or more wheels of the vehicle. When the clutch is disengaged i.e. disconnected to the crankshaft, the transmission is decoupled from the engine and does not transfer the driving torque to the wheel(s).

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[0004] Conventional clutches include a friction type clutch that is normally held in engaged position by a clutch spring. It is actuated through a manually operated clutch actuation lever, usually operated by left hand thereof. The clutch actuation lever is pivotally mounted to a handle bar of the vehicle adjacent to a hand grip on the handle bar and. is connected to clutch by means of a clutch cable. The manual operation requires an operator to grip the clutch lever and pull it back towards him. The pullback operation actuates the clutch to the disengaged position. After selecting a desired gear ratio, the operator releases his grip upon the clutch lever and the clutch gets engaged again. This manual operation provides a sense of controlling the operation of the vehicle to the operator arid hence forms a necessary part of a majority of vehicles.

[0005] Most often than not the operator keeps the clutch disengaged by keeping the clutch actuation lever retracted so that he may shift the vehicle to a suitable gear as the traffic signal turns green to enjoy a swift acceleration from a stop condition. However the continuous retraction of the clutch actuation lever corresponds to a continuous manually applied force. Repetitive retraction and release of clutch lever to disengage and engage the clutch leads to severe hand fatigue to the operator. More such actions subsequently result in an uncomfortable, painful and tiresome riding experience.

[0006] Recent developments have introduced several methodologies to reduce the operator fatigue, which reduces, the manual force necessary to operate the clutch actuation lever. In such systems, the input force by the operator increases and subsequently decreases as the clutch is disengaged. However such mechanisms are often housed inside the crankcase thereby consuming unnecessary space in the engine assembly and increase the overall complexity of the vehicle assembly. A need therefore exist for a simple yet operator friendly clutch actuation system that provide enough assisting force required to be applied by the operator upon the clutch actuation lever.

[0007] The present invention is directed to overcoming all or any of the problems as set forth above. Hence it is one of the objects of the present subject matter to provide a clutch manipulation system that assists and thereby reduces the manual clutch operating force by the vehicle operator and can be used effortlessly and conveniently. Another object of the present invention is to disclose a clutch manipulation system clutch manipulation system where the input manual force applied for actuating the clutch is assisted thereby reducing the . operator fatigue and providing better driving comfort.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other features, aspects, and advantages of the present subject matter will be better understood with regard to the following description, appended claims and accompanying drawings where:

[0009]Figure 1 shows a perspective view of a vehicle, particularly a three wheeled vehicle in accordance with an embodiment of the present subject matter.

[00010]Figure 2 shows a front view of the three wheeled vehicle in accordance with an embodiment of the present subject matter.

[00011]Figure 3 shows a rear view of the three wheeled vehicle in accordance with an embodiment of the present subject matter.

[00012]Figure 4 shows a perspective view of a clutch manipulation system, according to an implementation of the present subject matter.

[00013] Figure 5 shows a sectional side view of the clutch manipulation system in accordance to an implementation of the present subject matter.

[00014] Figure 6 shows an exploded view of a clutch manipulation sub-assembly in accordance to an implementation of the present subject matter.

DETAILED DESCRIPTION

[00015] In an implementation, the present subject matter describes a retractable clutch manipulation system havinga clutch manipulation sub-assembly, and an intermediate link mechanically connected to a clutch actuation lever. The intermediate link is supported by a clutch actuation link and establishes contact with the clutch manipulation sub-assembly. A housing is provided for supporting the clutch manipulation sub-assembly. The clutch manipulation system assists the clutch operating force applied manually by an operator of the vehicle to operate a clutch, and the clutch manipulation system is operable through the clutch actuation lever pivotally mounted on a handle bar of the vehicle and connected to the clutch actuation link.

[00016] In accordance with an embodiment of the present subject matter, the clutch manipulation sub-assembly provided in the clutch manipulation system includes a spring contained in a clutch anipulation unit. For instance, the spring contained in the clutch manipulation unit is a torsion spring. The clutch. manipulation sub-assembly also includes an actuating lever, a clutch manipulation pivot, an engaging member and a pin. In an embodiment, the clutch manipulation sub-assembly is in direct contact with the intermediate link through the engaging member.

[00017] According to yet another aspect of the present subject matter, the clutch actuation lever is provided with a free play zone and the clutch manipulation sub-assembly is operable after the free play zone is overcome. According to another aspect of the present subject matter, the other components of the clutch manipulation system are held outside of and supported on a crankcase of engine assembly of the vehicle.

[00018] Further, the clutch manipulation system of the present subject matter is supported outside of the crankcase of engine assembly. The clutch manipulation system includes the clutch actuation lever for manually operating a clutch. A clutch cable mechanically connects the clutch actuation lever to a clutch actuation link. An adjustable intermediate link pivotable at one end about a clutch shaft and supported by the clutch actuation link is provided. A clutch manipulation sub-, assembly having a torsion spring contained in a clutch manipulation unit, an engaging member in contact with the intermediate link and a pin is provided. A housing for supporting the clutch manipulation sub-assembly is also provided. When a manual force is applied on the clutch actuation lever by an operator, the clutch cable is pulled and rotates the clutch actuation link which in turn rotates the intermediate link through the. clutch shaft, and after a free play zone provided is overcome, the engaging member applies additional torque on the intermediate link in the direction of the clutch cable pull thereby assisting the manual force applied by the operator. Further, in an embodiment, when the clutch actuation lever is released by the operator, the intermediate link reverts to its original position due to preload of the spring of the clutch manipulation sub-assembly. Furthermore, in an embodiment, the clutch manipulation unit is circumferentially provided with . one or more preload adjustment spouts that enable setting up of preload on the clutch manipulation sub-assembly before assembling onto the crankcase of the engine assembly. In an embodiment, the clutch manipulation unit in addition to preventing dust entry into the torsion spring zone by acting as a dust cover, also acts as a preload adjusting means. For instance, preload is adjusted in the clutch manipulation system of the present subject matter depending upon the driver's need and ease of operation.

. [00019] Further in an embodiment, the clutch manipulation sub-assembly includes a guide and guide holder. For instance, the guide helps in preventing deflection of the torsion spring during preloading operation.and keeps the spring in line with the clutch manipulation pivot. In one embodiment, the clutch manipulation sub-assembly also includes a retainer. For example, the retainer helps in maintaining the clutch manipulation unit in preloaded condition after preloading operation so that uring assembly of the clutch manipulation sub-assembly onto the engine crankcase there is no change in the preload that is set.

[00020] Furthermore, in an embodiment, the clutch manipulation sub-assembly also includes one or more bearings, for example, double side sealed bearings. In an embodiment, the one or more bearings help in guiding the clutch manipulation pivot and in overcoming any overhang of the pivot. It also prevents dust and dirt entry into the clutch manipulation system.

[00021] In an advantageous embodiment, the clutch manipulation system of the present subject matter helps in enhancing the overall packaging of the engine assembly. For instance, the clutch manipulation unit of the present subject matter is capable of being retrofitted without aiiy major changes in the existing engine assembly. Further, the clutch manipulation system of the present subject matter is capable of achieving varying preload of the torsion spring, which provides assisting force in addition to the operating force applied by the driver thereby enhancing the clutch actuation. For instance, the preload, of the clutch manipulation system can be adjusted anytime depending upon the driver's ease of operation.

[00022] The. subject matter described herein relates to an clutch manipulation system for a vehicle. Various other features and embodiments of the mechanism according to the present subject matter here will be discernible from the following further description thereof, set out hereunder. In the ensuing exemplary embodiments, the vehicle is a three wheeled vehicle generally used as a passenger carrier. However it is contemplated that the concepts of the present invention may be applied to other types of vehicles within the spirit and scope of this invention including a motorcycle or a scooter type motorcycle. It is to be noted that the detailed explanation of the constitution of parts other than the subject matter , which constitutes an essential part has been omitted at suitable places.

[00023] Figure 1 describes a side view of a typical three wheeled vehicle, referenced by the numeral 100, driven by an internal combustion engine. It is commonly used as a passenger carrier. It has a front panel 101 along with a windscreen 102. The lower portion of the front panel is connected to a front wheel 104 with a wheel cover 103 stationed in between. A handle bar assembly 109 is present behind the front panel 101 which is used to operate the said three wheeled vehicle 100. The vehicle is laterally divided into two halves, along the line X-X, the first half having the driver's seat 107 while the second half has a long passenger seat 108 with a seating capacity of minimum three passengers. The rear panel 106 along with the second half of the vehicle containing the passenger seat 108 is supported on a pair of rear wheels 105 located on either side of the longitudinal axis of the vehicle 100. In this view, a steering tube assembly is not visible to an onlooker of the vehicle. Below the passenger seat, an internal combustion engine 300 is located used to power the vehicle.

[00024] Figure 2 illustrates the front view of the three wheeled vehicle with the side panels, coverings and styling parts removed. The said three wheeled vehicle 100 is supported on a frame structure spanning from the first half to the .

second half of the vehicle. A front fork steering column assembly is connected to the front wheel 104 and comprises a steering column assembly, front suspension 203 and a trailing arm 204. The steering column assembly comprises of a steering column tube 202, rotatably supporting the front wheel 104 and acting as a.

mechanical link between a handle bar 109 and the front wheel 104. The steering column tube 202 is engulfed by a head pipe 205 on all sides and welded or secured to the head pipe. The head pipe usually houses bearings that allow the steering tube to turn freely. A clutch actuation lever is pivotally mounted at a distal end of the handle bar 109 preferably on the left side thereof, such that the user may grip the handle bar and concurrently operate the clutch manipulation system 400 by retracting and releasing the clutch actuation lever. According to an aspect of the present subject matter, the clutch actuation lever 212 includes a clutch actuation lever 212.

[00025] Figure 3 shows the rear view of the three wheeled vehicle 100 with the rear panel removed and hence showing the otherwise invisible internal combustion engine 300 mounted on a posterior portion of the vehicle frame below the passenger seat 108. The internal combustion engine 300 produces the necessary power which is then transferred to the transmission through a clutch (not shown). The engine 300 is covered with a crankcase 301 at the rear which forms an outer surface of the engine. The engine power is transferred to the wheels through a clutch. Since the basic construction of a clutch is known to those versed in the art, the details have been omitted.

[00026] Figure 4 shows a perspective view of the clutch manipulation system 400, according to an implementation of the present subject matter. In an embodiment, the clutch manipulation system 400 includes a clutch actuation link 470 functionally coupled to the clutch actuation lever 212 and is capable of further actuating an intermediate link 490 when actuated. In an embodiment, the actuation of the intermediate link 490 causes the intermediate link 490 to rotate about a central slot of the clutch actuation link 470 until it attains a free play angle of rotation of the clutch actuation link 470. Upon overcoming the predetermined free play angle of rotation, the intermediate link 490 which is already in established contact with an engaging member 480 of the clutch manipulation sub-' assembly causes rotation of the engaging member 480 assisted by a cam follower 465. In an embodiment, the rotation of the engaging member 480 about a clutch manipulation pivot 515 (shown in Figure 5), causes actuation of the already preloaded torsion spring 520 (shown in Figure 5), which ensures that required torque is provided to assist the actuation of the clutch by the clutch actuation link 470.

[00027] Figure 5 shows a sectional side view of the clutch manipulation system 400 in accordance to an implementation of the present subject matter. In an embodiment, the clutch manipulation sub-assembly 405 is disposed outside a crankcase cover 525 of the engine assembly. The torsion spring 520 is preloaded inside the clutch manipulation unit 450. The engaging member 465 is attached to one end of the centrally disposed pivot 515 and is engaged to the intermediate link 490, which is connected to the clutch actuation link 470 mounted on to a clutch . shaft 510.

[00028] Figure 6 shows an exploded view of a clutch manipulation sub-assembly 405 in accordance to an implementation of the present subject matter. In an embodiment, the clutch manipulation sub-assembly 405 includes a centrally disposed pivot 515 onto which a torsion spring 520 is preloaded and held in line with the pivot 515 by means of one or more guides, for example, a guide top 610 and a guide bottom 615. In an embodiment, the guides 610, 615 are held in its position by means of a guide holder 455. Further, in an embodiment, a first bearing 620 and a second bearing 625 are disposed between the guide holder 455 and a housing 485 whose other end is attached to the crankcase cover (not shown). The pivot 515 is disposed with a cam follower 465 and an engaging member 480 at its other end. The torsion spring 520 is housed and prevented from dust entry by means of a clutch manipulation unit 450. In an embodiment, the clutch manipulation unit 450 includes one or more preload adjustment spouts 460 that helps in preloading of the torsion spring 520. Further in an embodiment, a retainer 475 is provided in the clutch manipulation sub-assembly 405, which helps in maintaining the preload of the torsion spring 520 during assembly of the clutch manipulation sub-assembly 405 on to the crankcase of the engine assembly.

1/ we claim:

1. A clutch manipulation system (400) for a vehicle (100) comprising:
a clutch actuation lever (212) capable of being manually actuated by an operator of said vehicle (100);

a clutch actuation link (470) mechanically coupled and capable of being actuated by said clutch actuation lever (212);

an intermediate link (490), one end of said intermediate link (490) rotatably coupled to said clutch actuation link (470); and a clutch manipulation sub-assembly (405) functionally connected to an other end of said intermediate link (490), said clutch manipulation sub-assembly (405) includes at least one torsion spring (520) for providing assisting force to operate a clutch of said vehicle (100) after a free play zone of said clutch actuation lever (212) is overcome.

2. The clutch manipulation system (400) as claimed in claim 1, wherein said clutch manipulation sub-assembly (405) includes a clutch manipulation unit (450) for housing said at least one torsion spring (520), and wherein said clutch manipulation unit (450) includes at least one preload adjustment spout (460) for preloading said at least one torsion spring (520).

3. The clutch manipulation system (400) as claimed in claim 1, wherein said clutch manipulation sub-assembly (405) includes at least one retainer (475) for maintaining the preload of the torsion sprihg(520) during assembly of said clutch manipulation sub-assembly (405) on to a crankcase (525) of an internal combustion engine (300) of said vehicle (100).

4. The clutch manipulation system (400) as claimed in claim 1, wherein said clutch manipulation sub-assembly (405) includes at least one guide (610, 615) for preventing deflection of said torsion spring (520) during preloading and for maintaining said torsion spring (520) in line with a centrally disposed clutch manipulation pivot (515).

5. The clutch manipulation system (400) as claimed in claim 4, wherein said clutch manipulation sub-assembly (405) includes at least one bearing (620, 625) for guiding and overcoming overhang said clutch manipulation pivot (515), and wherein said at least one bearing (620, 625) prevents entry of dust into said clutch manipulation unit (450).

6. The clutch manipulation system (400) as claimed in claim 1, wherein said clutch manipulation sub-assembly (405) includes an engaging member (480) functionally connected to said another end of said intermediate link (490), and wherein said engaging member (480) rotates along with the rotation of the intermediate link (490) when said clutch actuation lever (212) overcomes the predetermined free play angle of rotation and applies additional torque on said intermediate link (490) to assist the clutch actuation force provided by the operation of the clutch actuation lever (212).

7. The clutch manipulation system (400) as claimed in claim 1, wherein said clutch manipulation sub-assembly (405) includes a housing (485) to hold said clutch manipulation sub-assembly (405) externally of the crankcase (525) of the engine (300).

8. The clutch manipulation system (400) as claimed in any one of the. preceding claims, wherein upon release of said clutch actuation lever (212), the intermediate link (490) reverts to its original position due to preload acting on said clutch actuation link (470) through a clutch actuation spring.

9. The clutch manipulation system (400) as claimed in any one of the preceding claims, wherein rotational angle of said intermediate link (490) is adjustable about a slot centrally disposed on said clutch actuation link (470)

10. A two-or three-wheeled vehicle (100) comprising a clutch manipulation system (400) as claimed in any one of the preceding claims.