Title of Invention

IMPROVED IN STEERING SYSTEM OF 2 WHEELED VEHICLES

Abstract

An improved steering control system for two wheeled vehicles comprising a steering tube (1), a steering bracket (2) having a pair of lugs (10) fixed on the handle bar of steering system of vehicle, a damper mounting bracket (3) fixed to the steering tube (1), a damper (4) mounted on the said damper mounting bracket (3), a spring plate (6) mounted on the said steering bracket (2) with the help of said lugs (10), the said spring plate (6) is provided with a slot (9)and a curvature corresponding to the curve of turning of handle bar and the said damper being provided with a curvature matching with curvature of said spring plate in horizontal plane there by providing maximum contact area between said damper and said spring plate and the said spring plate exerting desired pressure on the said damper in straight driving position of handle bar of vehicle and the said contact area and pressure being progressively reduced in the turning position of handle bar of vehicle.

Full Text

FORM - 2 THE PATENTS ACT, 1970 (39 of 1970) PROVISIONAL / COMPLETE SPECIFICATION SECTION 10 TITLE "AN IMPROVED STEERING CONTROL SYSTEM FOR TWO WHEELED VEHICLES" APPLICANT BAJAJ AUTO LIMITED, an Indian limited Company, of Akurdi, Pune 411 035, Maharashtra, India The following specification particularly describes nature of the invention and the manner in which it is to be performed 23-10-2006 This invention relates to an improved steering control system of two wheeled vehicles namely motorcycle which have handle bar type steering control system. This invention particularly relates to two wheeled vehicles having telescopic type suspension. In order to simplify the explanation, two wheeled vehicles explained above are called as 'vehicles' in this specification. The handle bar of these vehicles is made up of steel tube bent to suit the fitment on the vehicle components. When the handle bar is turned, the suspension parts are rotated about the steering axis. This moves the front wheel in the direction in which handle bar is rotated and the vehicle is turned in that direction. One of the disadvantages experienced in the above steering control system is that, when the vehicle is driven in straight line, particularly at high speed, the vehicle tends to vobble and deviate from the straight line path due to the reasons such as road conditions, variation in the weight of components on left side and right side of the vehicle etc. The rider has to apply some efforts on any one side of the handle bar to keep vehicle moving in straight line. In majority of cases, high speed driving is on the straight line and application of effort is unnecessary. This adds to fatigue of the driver. 2- Yet another disadvantage experienced in the above steering control system is, due to vobbling of vehicle at high speed, the driver tends to loose the control of the vehicle and prove fatal to rider and people nearby. In order to avoid above disadvantages and reduce driver fatigue, we have developed an improved steering control system of the vehicle. In case of some of the three-wheeled vehicles provided with handle bar type steering control system, an arrangement of metal parts is provided which helps in avoiding the vobbling of the vehicle and vibrations of the handle bar. However, we have found that metallic damping arrangement used in three wheeled vehicles cannot be used in these vehicles, because of design constraints. Further, in the system used in three wheelers, the damping force remains constant irrespective of angular position of the handle bar. 3 Therefore, one of the objects of the present invention is to avoid the disadvantages experienced in the known steering control system, in the class of two wheeled vehicles mentioned above. A further object of the invention is to provide a steering control system the damper of which is made of nylon, synthetic plastic or rubber thereby avoiding wobbling and vibration of handlebar. A still further object of the invention is to provide a system, which will offer just enough speed during turning. The present invention provides an improved steering control system for two wheeled vehicles comprising a steering tube , a steering bracket having a pair of lugs fixed on the handle bar of steering system of vehicle, a damper mounting bracket fixed to the steering tube , a damper mounted on the said damper mounting bracket, a spring plate mounted on the said steering bracket with the help of said lugs , the said spring plate is provided with a slot and a curvature corresponding to the curve of turning of handle bar and the said damper being provided with a curvature matching with curvature of said spring plate in horizontal plane there by providing maximum contact area between said damper and said spring plate and the said spring plate exerting desired pressure on the said damper in straight driving position of handle bar of vehicle and the said contact area and pressure being progressively reduced in the turning position of handle bar of vehicle. The steering control system of two wheeled vehicle will now be explained with reference to the figures accompanied with Provisional Specification, wherein 4 Fig. 1 illustrates in front perspective view of the improved steering control system of the present invention with handle bar in straight position. Fig. 2 illustrates in front perspective view the of the improved steering control system of the present invention with handle bar in turned position. Fig. 3 illustrates the relevant parts of the improved steering control system of the present invention in a plan view The present invention will now be described in detail with reference to the figures 1, 2 and 3. The improved steering control system for vehicles provided with telescopic type suspension having a dampening system to avoid unintentional movement of handle bar during driving the vehicles in straight line and to generate progressively reduced contact areas in registration with increased turning of handle bar thereby restricting any increase in the steering efforts during turning of vehicle consists of essential parts like steering tube (1), steering bracket (2) with a pair of lugs (10), damper mounting bracket (3), damper (4), bolts (5), spring plate (6) provided with hole and a slot (9), a bolt (7) and a shoulder bolt (8). With reference to figures 1 and 2, the steering tube (1) is a part of frame assembly (not shown) of the vehicle, which allows rotation of the handle bar (not shown) when turned for steering the vehicle. The steering bracket (2) is fixed to the handle bar, which turns when the handle bar is turned by the rider about the axis A1 to turn the vehicle. 5 The steering tube (1) is fixed with a damper mounting bracket (3) to which a damper (4) made of resilient material like nylon, rubber, synthetic plastic is mounted with the help of bolts (5). The steering bracket (2) is mounted with a spring plate (6) as shown in the figure 3 and is held with the help of bolt (7) and a shoulder bolt (8) passing through the holes made in lug(10). The spring plate (6) is provided with a slot (9) for passing through shoulder bolt(8).The spring plate (6) is provided with curvature in horizontal plane substantially corresponding to turning curve of handle bar. The location of and the curvature of spring plate (6) and damper (4) are selected such that it exerts just enough frictional force in the horizontal plane in order to avoid vobbling without increasing steering effort and the contact area is reduced with increased turning of handle bar so that the steering effort is not increased for intentional turning (Fig. 2).Due to the location and the curvature of said spring plate (6) and said damper (4), the efforts while turning are not increased. This is further explained in following paragraph. In normal driving in straight ahead condition, the spring plate (6) exerts a predetermined pressure on damper (4). This pressure is just sufficient to maintain the handle bar in straight ahead positions the rider initiates turning of the handle bar thereby progressively reducing the contact area between spring plate and damper and the pressure gets progressively reduced which reduces the effort required for turning. Due to this the spring plate tries to achieve comparatively straight position. In order to take care of this movement of spring plate , the slot (9) and shoulder bolt (8) are provided. 6 We claim: 1. An improved steering control system for two wheeled vehicles comprising a steering tube (1), a steering bracket (2) having a pair of lugs (10) fixed on the handle bar of steering system of vehicle, a damper mounting bracket (3) fixed to the steering tube (1), a damper (4) mounted on the said damper mounting bracket (3), a spring plate (6) mounted on the said steering bracket (2) with the help of said lugs (10), the said spring plate (6) is provided with a slot (9)and a curvature corresponding to the curve of turning of handle bar and the said damper being provided with a curvature matching with curvature of said spring plate in horizontal plane there by providing maximum contact area between said damper and said spring plate and the said spring plate exerting desired pressure on the said damper in straight driving position of handle bar of vehicle and the said contact area and pressure being progressively reduced in the turning position of handle bar of vehicle. 2. An improved steering control system for two wheeled vehicles as claimed in claim 1 wherein said damper(4) is mounted on damper mounting bracket (3) by a known fastening means like bolts or rivets. 3. An improved steering control system for two wheeled vehicles as claimed in claim 1 or 2 wherein said damper (4) is made of any resilient material such as nylon, synthetic plastic, rubber. 4. An improved steering control system for two wheeled vehicles as claimed in claim 1 wherein said spring plate (6) is mounted on the lugs (10) of the steering bracket (2) with help of a bolt (7) and a shoulder bolt(8), the said shoulder bolt passing through the slot (9) of said spring plate (6). 5. An improved steering control system for two wheeled vehicles substantially as herein described with reference to figures 1 to 3 of the provisional specification. Dated this 1st day of August 2002. M K Chakrabarti of MKC & Associates Applicant's Attorney 3

Documents:

659-mum-2001-claims(granted)-(23-10-2006).doc

659-mum-2001-claims(granted)-(23-10-2006).pdf

659-mum-2001-correspondence 1(12-04-2006).pdf

659-mum-2001-correspondence 2(20-03-2007).pdf

659-MUM-2001-CORRESPONDENCE(26-10-2010).pdf

659-mum-2001-correspondence(ipo)-(14-07-2006).pdf

659-mum-2001-drawing(23-10-2006).pdf

659-mum-2001-form 1(12-07-2001).pdf

659-mum-2001-form 13(19-10-2006).pdf

659-mum-2001-form 18(11-07-2005).pdf

659-mum-2001-form 2(granted)-(23-10-2006).doc

659-mum-2001-form 2(granted)-(23-10-2006).pdf

659-mum-2001-form 3(12-07-2001).pdf

659-mum-2001-form 4(01-08-2002).pdf

659-mum-2001-form 4(13-04-2006).pdf

659-mum-2001-form 5(01-08-2002).pdf

659-MUM-2001-GENERAL POWER OF ATTORNEY(26-10-2010).pdf

659-mum-2001-power of attorney(12-07-2001).pdf

659-mum-2001-power of attorney(19-10-2006).pdf

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