A Cable Assembly for Motor Vehicles

FIELD OF THE INVENTION

[001] The present invention relates to a cable assembly for motor vehicles. BACKGROUND OF THE INVENTION

[002] Motor vehicles use cables for braking systems, clutch systems, accelerator systems etc. A typical cable is operationally coupled to an actuator on one end and to a respective component on another end. The actuator is mostly a lever, like a brake actuator lever or a clutch actuator lever; whereas the components are brake assemblies or clutch assemblies or accelerator assemblies. Thus, operation of the actuator leads to an effect on the respective component. Accordingly, it is desired that when an actuator is operated, an effect in the respective component is immediately seen. For instance, when a user operates the lever of a brake, the user expects the vehicle to start slowing down and eventually stop as soon as the lever is pressed.

[003] However, slackness in cables pose many problems due to which there is a delay or complete failure in producing an effect when the actuator is operated. Figure 4 shows prior art configuration of a cable 200 coupled to a lever 250. The cable comprises an outer cable 210 and an inner cable 220 disposed inside the outer cable 210. A shank 230 is circumferentially affixed to an end of the outer cable 210. The shank 230 is generally divided into three regions: a first region 230a being circumferentially affixed on the outer cable 210, a second region 230b being the collar which abuts against a tube 240 disposed inside a lever holder 260, and a third region 230c which goes inside the tube 240. As such, outer cable 210 is held in place and the inner cable 220 passes through the tube 240 whereby a bullet 270 formed at an end of the inner cable 220 engages with the lever 250. However, the outer cable 210 generally slacks, and a curvature is formed. Accordingly, when the lever 250 is actuated, the lever 250 will have to travel to overcome the slackness in the outer cable 210. Only when the outer cable 210 is straightened, lever 250 further travels to a desired distance to pull the inner cable 220 in accordance with the requirement. The additional distance to be traveled by the lever due to slackness of the outer cable 220 also gives an unwanted spongy feeling to a driver. [004] Typically, the lever 250 is provided with free play due to which the lever 250 has to travel a predetermined distance before the inner cable 220 is pulled to cause an effect on corresponding component. Thus, additional distance required to be traveled by the lever 250 due to slackness of the outer cable 220, as seen hereinbefore, adds with the distance required due to free play. For example, in case the lever 250 is provided with a free play of 20 mm and additional distance required to be travel due to slackness is 3 mm then, assuming a lever ratio of 5 mm, total distance required by the lever 250 to travel would be 35 mm before the inner cable 220 is pulled. As such, for a lever which can travel a maximum distance of 70 mm before it touches a handlebar of a vehicle, the lever is left with only 35 mm of effective travel distance. It may be noted that free play increases with time due to wear and tear of the components. For example, in case of braking systems, free play increases with wear and tear of brake liner and drum. Such increase in free play together with slackness in outer cable 220 further impact the effective travel distance of the lever 250.

[005] Particularly in case of braking systems, when the brake lever is left with reduced amount of travel distance due to free play and slackness, there are high chances that a rider may hit the handle bar of the vehicle in case of panic braking. Such phenomenon is generally referred as bottoming and is unwanted and dangerous too as it may lead to the vehicle toppling leading to accident.

[006] Thus, there is a need in the art for a cable assembly which at least addresses the problem of slackness of outer cable. SUMMARY OF THE INVENTION

[007] In one aspect, the present invention is directed to a cable assembly for a motor vehicle. The cable assembly having a cable, a shank abutted on an end of the cable and a tube. At least a portion of the shank has a tapered outer surface extending with decreasing diameter towards a second end of the shank. The tube has an entry end, an exit end and a tapered bore extending with decreasing diameter from the entry end to the exit end.

[008] In an embodiment of the invention, the cable is a coaxial cable having an inner cable, and an outer cable sleeve, the inner cable movable axially inside the outer cable sleeve.

[009] In another embodiment of the invention, the shank abuts on an end of the outer cable sleeve. Further, the tapered bore of the tube is configured to receive the tapered portion of the shank through the entry end, and to allow the inner cable to pass through the exit end whereby the tapered portion of the shank frictionally engages with the tube.

[010] In yet another embodiment, the tapered bore is tapered at an angle ranging approximately between l°to 45° from axial axis of the tube. [Oil] In a further embodiment of the invention, the tube resides in a component assembly of the motor vehicle. The component assembly comprises a brake assembly or a clutch assembly. [012] In another aspect, the present invention is directed to a lever holder for a motor vehicle. The lever holder is mounted on a handlebar of the motor vehicle and coupled with a lever movable relative to the handlebar. The lever holder comprising a tube having an entry end, an exit end and a tapered bore extending with decreasing diameter from the entry end to the exit end.

[013] In an embodiment of the invention, the tapered bore is configured to receive a shank abutted on an end of a cable, wherein at least a portion of the shank having a tapered outer surface extending with decreasing diameter towards a second end of the shank, the tapered portion of the shank frictionally engages with the 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 left side view of an exemplary vehicle, in accordance with an embodiment of the present subject matter.

Figure 2 shows a general layout of a synchronized braking system having a cable assembly in accordance with an embodiment of the invention.

Figure 3 illustrates a schematic view of a front wheel, in accordance with an embodiment of the present subject matter.

Figure 4 shows configuration of a cable assembly according to prior arts.

Figure 5a shows a cable assembly along with an actuation lever in accordance with an embodiment of the invention.

Figure 5b is a schematic representation of a cable with a shank in accordance with an embodiment of the invention.

Figure 6 shows a tube residing in a lever holder in accordance with an embodiment of the invention. Figure 7 shows a tube residing in a lever holder in accordance with an embodiment of the invention.

Figure 8 shows a perspective view of the cable assembly along with an actuation lever in accordance with an embodiment of the invention.

Figure 9 shows a front brake panel assembly in accordance with another embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[015] The present invention relates to a cable assembly for motor vehicles.

[016] Figure 1 illustrates a left side view of an exemplary vehicle 10, in accordance with an embodiment of the present subject matter. The vehicle 10 comprises a frame assembly 105. The frame assembly 105 includes a head tube 105A, a main frame assembly 105B. One or more front suspensions 110 connect a front wheel 115 to a handlebar assembly 190, which forms a steering assembly of the vehicle 10. The steering assembly is rotatably disposed about the head tube 105A. The main frame assembly 105B extends rearwardly downward from the head tube 105A and includes a bent portion thereafter extending substantially in a longitudinal direction. Further, the frame assembly 105 includes one or more rear tubes 105C extending inclinedly rearward from a rear portion of the main frame assembly 105B towards a rear portion of the vehicle 10. [017] The vehicle 10 includes a power unit comprising at least one of an internal combustion (IC) engine 125 and a traction motor 135. For example, the traction motor 135 may include a brush less direct current (BLDC) motor. The power unit is coupled to the rear wheel 145. In one embodiment, the IC engine 125 is swingably connected to the frame assembly 105. In the present embodiment, the IC engine 125 is mounted to the swing arm 141 and the swing arm 141 is swingably connected to the frame assembly 105. The traction motor 135, in one embodiment, is disposed adjacent to the IC engine 125. In the present embodiment, the traction motor 135 is hub mounted to the rear wheel 145. Further, the vehicle 10 includes a transmission means 131 coupling the rear wheel 145 to the power unit. The transmission means 131 includes a continuously variable transmission, an automatic transmission, or a fixed ratio transmission. A seat assembly 151 is disposed above the power unit and is supported by the rear tubes 105C of the frame assembly 105. The seat assembly 151 is hingedly openable. The frame assembly 105 defines a step-through portion ST ahead of the seat assembly 151. A floorboard 155 is disposed at the step-through portion ST, wherein a rider can operate the vehicle 10 in a seated position by resting feet on the floorboard 155. Further, the floorboard 155 is capable of carrying loads.

[018] The vehicle 10 includes an on-board battery (not shown) that drives the traction motor 135. Further, the frame assembly 105 is covered by plurality of body panels including a front panel 160A, a leg shield 160B, an under-seat cover 160C, and a left and a right-side panel 160D, mounted on the frame assembly 105 and covering the frame assembly 105 and parts mounted thereof.

[019] In addition, a front fender 165 is covering at least a portion of the front wheel 115. In the present embodiment, the front fender 165 is integrated with the front panel 160A. A utility box is disposed below the seat assembly 151 and is supported by the frame assembly 105. A fuel tank (not shown) is disposed adjacent to the utility box. A rear fender 175 is covering at least a portion of the rear wheel 145 and is positioned below the fuel tank and upwardly of the rear wheel 145. One or more suspension(s) 195 are provided in the rear portion of the vehicle 10 for connecting the swing arm 141 and the rear wheel 145 to the frame assembly 105 for damping the forces from the wheel 145 and the power unit from reaching the frame assembly 105.

[020] Furthermore, the vehicle 10 comprises of plurality of electrical and electronic components including a headlight 185 A, a taillight 185B, a transistor-controlled ignition (TCI) unit (not shown), an alternator (not shown), a starter motor (not shown). Further, the vehicle 10 includes an anti-lock braking system (ABS), a synchronous braking system (SBS), or a vehicle control system (VCS).

[021] Figure 2 illustrates a general layout of a synchronized braking system 100 having a cable assembly in accordance with an embodiment of the present invention. As shown in the Figure, brake cable 110 is coupled with a brake lever 140 on one end and with a rear brake assembly 170 on another end. Brake cable 110 coupled with the brake lever 140 on one and brake cable 130 coupled with a brake lever 150 on one end are coupled with a front brake assembly 180 on another end. The brake levers 140, 150 are mounted on a handlebar 190. Thus, actuation of the brake lever 140 will cause rear brake assembly 170 and front brake assembly 180 to operate synchronously. Actuation of the lever 150 will cause only the front brake assembly 180 to operate.

[022] Figure 3 illustrates a schematic view of a front wheel, in accordance with an embodiment of the present subject matter. The front wheel 115 comprises a wheel rim 117, which supports a tyre. In the depicted embodiment, the front wheel 115 is an alloy type wheel with an arm portion and a hub portion integrated with the rim 117. In the depicted embodiment, the front wheel-brake 180 is a drum brake mounted to the hub portion of the front wheel 115. For instance, in an embodiment, the cable assembly includes a synchronized-front brake cable 110 and the independent- front brake cable 130 may be connected to the front wheel-brake 180.

[023] The front-wheel brake 180 includes a cam lever 119 and each of the synchronized-front brake cable 110 and the independent-front brake cable 130 are functionally connected to the cam lever 119. The cam lever 119 is rotatably supported on a plate member 121 of the front wheel- brake. The plate member 121 is provided with at least a cable abutment 123, wherein one end of outer sheaths of both the brake cables 110, 130 are supported on the cable abutment 123 and inner cables of the brake cables are slidable through the outer sheaths and the cable abutment 123. The front-brake lever 150 (shown in Figure 2) is connected to the cam lever 119 of the front wheel-brake 180 through the independent- front brake cable 130 and the synchronized-brake lever 140 (shown in Figure 2) is connected to the cam lever 119 of the front wheel 115 through the synchronized front brake cable 110.

[024] Figure 5a and Figure 8 depict a cable assembly 300 of the present invention at an actuator end. The cable assembly 300 has a coaxial cable 310 as further elaborated in Figure 3b. The coaxial cable 310 has an outer cable sleeve 312 and an inner cable 314. The outer cable sleeve 312 extends from a first end 312a to a second end 312b (not shown). The first end 312a is adjacent to a lever 350, whereas the second end 312b is adjacent to a component (not shown). [025] The inner cable 314 is axially movable inside the outer cable sleeve 312 whereby, the inner cable 314 extends between a lever end 314a and a component end 314b (not shown). Thus, the lever end 314a of the inner cable 314 extends out of the first end 312a of the outer cable sleeve 312 and the component end 314b of the inner cable 314 extends out of the second end 312b of the outer cable sleeve 312.

[026] The lever end 314a and the component end 314b of the inner cable 314 each have a bullet 316 formed at the respective ends. The bullets are used to couple the inner cable 314 to a respective unit. Thus, as shown in Figures 5a, 5b and 8, the bullet 316 formed at the lever end 314a of the inner cable 314 is used to couple the lever end 314a of the inner cable 314 to a lever 350. In this regard, means for engaging the bullet 316 is provided in the lever 350.

[027] Further, as shown in Figures 5a, 5b and 8, the cable assembly 300 has a shank 320 abutted on an end of the outer cable sleeve 312. The shank 320 is a metal tube configured to receive the outer cable sleeve 312 to fasten the outer cable 312 to either an actuator or a component. In this regard, at least a portion of the shank 320 has a tapered outer surface extending with decreasing diameter towards an end of the shank 320.

[028] As shown in Figure 5b, in an embodiment of the invention, the shank 320 extends from a first end 320a’ to a second end 320b’, and has a first portion 320a and a second portion 320b. Internal wall of the first portion 320a of the shank 320 has an annular profile and configured to circumferentially abut on the first end 312a of the outer cable sleeve 312. The second portion 320b of the shank 320 has a tapered outer surface. The tapered outer surface decreases in diameter towards the second end 320b’ of the shank 320 such that at the second end 320b’, the shank 320 has lowest outer diameter. Thus, the second portion 320b of the shank 320 forms a circumferential periphery around the inner cable 314 which extends out of the outer cable sleeve 312. In this regard, inner diameter of the second portion 320b of the shank is more than outer diameter of the inner cable 314, such that the inner cable 314 is axially movable inside the second portion 320b of the shank 320. [029] In an embodiment of the invention, and as described hereinabove, the shank 320 is present on a first end 312a of the outer cable sleeve 312 which is adjacent to a lever 250. In another embodiment, the shank 320 is present on the second end 312b of the outer cable sleeve 312, which is adjacent to a component. In yet another embodiment, the shank is present on the first end 312a of the outer cable sleeve 312 and the second end 312b of the outer cable sleeve 312.

[030] Further, as shown in Figures 5a, 6 and 7, the cable assembly 300 has a tube 330. In an embodiment of the invention, the tube 330 resides in a lever holder 340 coupled with a lever 350. Thus, operation of the lever 350 causes the inner cable 314 to move axially. The tube 330 extends from an entry end 330a to an exit end 330b, and has a tapered bore 360 made therethrough. The tapered bore 360 extends from the entry end 330a to the exit end 330b, such that diameter of the bore 360 decreases from the entry end 330a towards the exit end 330b. In this regard, the tapered bore 360 is defined by inner wall 370 of the tube 330 wherein the inner wall 370 slopes towards the exit end 330b. In an embodiment of the invention, as shown in Figure 7, the bore is tapered at an angle a, from axial axis 332 of the tube 330. The angle a ranges between 1° to 45°.

[031] The bore of the tube 330 is configured to receive the tapered second portion 320b of the shank from the entry end 330a of the tube 330 and to allow the inner cable 314 to pass through the exit end of the tube 330b. Thus, the tapered second portion 320b of the shank 320 frictionally engages with the tube 300. In an embodiment of the invention, slope of the second portion 320b of the shank 320, corresponds to slope of the inner wall 370 of the tube 330, such that the entire second portion 320b of the shank frictionally engages with the inner wall of the tube 330. As such, the tapered second portion 320b of the shank 320 snuggly abuts with inner wall 370 of the tube 330. Further, the inner cable 314 along with the bullet 316 is drawn outwards such that the inner cable is made to pass through the slit of the tube 330 to reside inside the tube 330, and the bullet is made to abut outer wall of the exit end 330b of the tube 330. The inner diameter of the exit end 330b of the tube 330 is more than the outer diameter of the inner cable 314 and less than outer diameter of the bullet 316. Thus, once the inner cable 330 passes through the bore, it does not slip out due to presence of the bullet 316. The configuration thus achieved leads to only an axial movement of the inner cable 314. [032] In an embodiment of the invention, and as described hereinabove, and as shown in Figure

5a, Figure 6, Figure 7 and Figure 8, the tube 330 is present in an actuator end, i.e. in the lever holder 340 and thus engages with the shank 320 of the present invention in the lever holder 340. In another embodiment, the tube 330 is present in a component assembly of the vehicle and thus engages with the shank 320 present at the second end 312b of the outer cable sleeve 312. The component assembly may be a brake assembly or a gear assembly. In yet another embodiment, the tube 330 is present in both the actuator end and the component assembly and engages with the shank 320 at the first end 312a of the outer cable sleeve 312 and the shank 320 at the second end 312b of the outer cable sleeve 312.

[033] Figure 9 shows front brake panel assembly 180 in accordance with another embodiment of the invention. In this embodiment, the front brake panel 180 includes a front brake panel cable abutment structure 182, which is integrated to an outer surface of the brake panel 180. In an embodiment, the front brake panel cable abutment 182 is provided with one or more tapered bores 182a, 182b to receive the brake cables (not shown). The brake cables are also provided with corresponding tapered shank portions to snugly fit within the tapered bore 182a, 182b of the front brake panel 180 cable abutment structure 182.

[034] Advantageously, the cable assembly of the present invention solves the problem of slackness of the outer cable sleeve. Due to the configuration of the shank and the tube as disclosed hereinabove, the outer cable sleeve is snuggly fastened with the tube. Thus, the outer cable sleeve stays intact during operation of the inner cable by the lever. Further, since the bore of the tube is tapered, the inner cable only moves axially and therefore does not slack inside the tube. As such, any spongy feeling due to slackness of the outer cable and inner cable is eliminated. Further, since slackness in the outer cable is eliminated by the present invention, it will be the free play alone which will be responsible for reduction in effective travel distance of the lever. Thus, chances of bottoming are considerably reduced.

[035] 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 modification may be made without departing from the scope of the invention as defined in the following claims.