IMPROVED THREE-WHEELER FOR TOURIST, SPORTING USE IN GENERAL

Abstract: Three-wheeler having two front wheels acting as directional wheels, and one rear wheel acting as the driving wheel, endowed with a considerably high transversal and longitudinal stability thanks to the particular ratio between its values of wheel base and track, to the arrangement of its seats, and to its rear suspension, the vehicle being equipped with reverse gear installed on one of its front wheels.

Description: • IMPROVED THREE-WHEELER FOR T0URI5T, SPORTING U5E IN GENERRL" Disclosure The present invention relates to a three-wheeler characterized in that it has two front directional wheels, and a rear driving wheel. The driving wheel is connected with the engine through a single-arm swinging fork, and the motion transmission is of the chain-transmission or of the shaft-transmission type. Rll of the three wheels have an independent suspension with shock absorbers. The vehicle is endowed with a considerably high transversal and Longitudinal stability, which is provided by the particular value of the ratio of its base wheel value to its track value, the arrangement of its seats, its particular rear suspension, with particular reference to the installation of an engine of motor-cycle type, and is furthermore equipped with reverse gear, installed on one of its front wheels. It is well known that various models of three- wheelers exist, in which their single driving wheel may be a front wheel or a rear wheel; in any case, nearly all of them are affected by problems of side stability when running along bends, and show a trend to turn over owing to the action of centrifugal force. These drawbacks are above all due to problems of technical nature, and of design "philosophy", i.e.: - to the high position of the barycentre, to the too targe track as compared to the base wheel, to the type of suspension, to the side-by-side arrangement of the seats and to the wrong weight distribution. Rll the above does not enable the vehicles to be driven at high speeds, and conditions the type of use, limiting it to low-speed vehicles for prevailingly urban service. On the contrary, the purpose of the improved vehicle proposed by the present invention is precisely of getting rid of all of the above said drawbacks, with a vehicle being provided which is fast, safe, and, above all, stable even at high speeds. In fact, the difficulty due to the unfavourable ratio of the value of the base wheel to the value of the track is favourably solved; several tests demonstrated that the base wheel should be equal to the product of the track Cmm) multiplied by 1.58-1.60, preferably by 1.70. This coefficient, which is fixed, causes the values of the base wheel and of the track to proportionally vary as a function of the dimensions of the vehicle. The result is a high transversal and directional stability at high speeds. The rear wheel is installed in a shifted position relatively to the middle axis of the vehicle: When the suspension is a single-arm suspension the rear wheel has to be shifted by a certain distance towards the vehicle side on which the asymmetrical weight is Larger, above all towards the engine and a car wheel having a large cross-section surface-area is adopted, in order to achieve a better grip on ground surface. The arrangement of the seats, which are installed in tandem arrangement along the middle axis of the vehicle increases the transversal stability, while simultaneously lowering the rolling centre. The front suspensions are of the type with upper and lower triangle arms and central spring-shock absorber. Their length is determined taking into due account the rolling centre of the whole vehicle. The rear suspension is accomplished with a shaft transmission with two shock absorbers in a particular position in order to prevent the rear wheel from bouncing during the acceleration step. In fact, it is well-known that this type of transmission on the bevel gears of the driving wheel tends to cause the rear side of the vheicle to lift, with the shock absorber being consequently not allowed to operate under compression conditions, but, on the contrary, said shock absorber being caused to extend, becoming rigid, with the driving wheel consequently bouncing and skidding with negative effects on the directional i ty . In order to remove such a drawback, two differently calibrated shock absorbers have to be used. The main shock absorber has to be positioned vertically, and the second shock absorber has to be positioned horizontally, with both of them being hinged onto an "L"-shaped rocker lever which rotates according to the forces it is submitted to. When the vehicle is traveling, the main shock absorber is used for springing purposes, operates under compression, and, during such a funtion, the second shock absorber is not active. When the vehicle is starting, or under the acceleration conditions, the main shock absorber extends owing to the action of the shaft transmission; when said main shock absorber reaches its stroke end, causes the ".."-shaped rocker lever to rotate towards the secondary shock absorber which, by operating under compression conditions, compensates for the stiffness of the firs shock absorber, thus preventing the driving wheel from undergoing bouncing. The reverse gear, essential in a three-wheeler, is obtained by means of a chain transmission. Rn electrical motor provided with a sprocket gear transmits the motion, through a chain, to a sprocket wheel keyed onto an axle. shaft. Said transmission axle shaft, equipped with a constant-velocity universal joint, is fastened to a directional front wheel. Rn electromechanϊcal,.device enables the electrical motor to operate and to transmit the motion to the wheel only when the main engine is idling. Said electrical motor also acts as the parking brake, because, by means of a relevant control means, it can be . locked. The top cover the three-wheeler is equipped with o can be laterally overturned by 90 in the direction opposite to the vehicle entrance side, and can be totally removed or use during summer time. R mechanical device makes it possible said top cover to be totally disengaged also at its hinge side, in order to enable the vehicle passenger(s) to easily abandon the vehicle in case of a vehicle overturning or of an accident. Said device can be controlled from the interior of the vehicle, and from the outside by means of a lever. Rs regards the vehicle bodywork, beside the overturning top cover, the vehicle is furthermore equipped with a front bonnet and with a rear bonnet, which can be overturned against the traveling direction*. " For water-cooled engines, the front bonnet is provided with a front opening for cooling air inlet. Rir, after passing through the radiator, outflows to the atmosphere through a purposely provided central opening, having a baffle-shaped edge, before the vehicle wiridscreen. The above and still other functional and design characteristics of the three-wheeler according to the instant finding can be better understood with the aid of the figures of the hereto attached drawing tables supplied for indicative and non-Limitative purposes, in which : Figure 1 shows the vehicle complete with the main components of its bodywork. Figure 2 shows the direction of overturning of the front bonnet and of the rear bonnet. Figure 3 shows the path along which the cooling air flows. Figure 4 shows the structure of vehicle chassis. Figure 5 shows the operating mechanism of the reverse gear. Figures 6 and 7 show the kinematic system for rear suspension operation. Figure 6 shows the three-wheels support base of the three-wheeler and the relevant system of calculation of the base wheel/track ratio. Figure 9 shows the overturning top cover with fast-disengagement mechanism. With particular reference ' to the above said figures, we can observe that the vehicle according to the present invention shown in Drawing table 1, Figure 1, is complete with its main bodywork parts, which are: - (1) front bumper, C2) front bonnet, C3) righthand/ Lefthand mudguard/front bonnet connection piece, C4) rear engine bonnet, C5) overturning top cover . Bonnets (2) and (4) are overturning forwards, against the traveling direction, and are hinged in C7) and (θ) . The cooling of the radiator is obtained by means of air entering through the front air inlet C7) provided in the bumper CD, and leaving through the air outlet (6) provided in the front bonnet before the windscreen, with the front edge of said air outlet being so shaped as to act as a baffle. In Drawing table 2, Figure 4, the tubular structure of the chassis is shown in side view R, in top view B and with the stiffening tie-rods C. Dimensions are indicative only. The construction material is metal section bar, with different cross-section surface-areas. In Drawing table 3, Figure 5, the reverse gear transmission system is composed by an electrical motor B fastened onto a motor support R. The electrical motor B transmits the motion, through chain C, to the shaft E equipped with a constant-velocity universal joint D, through a sprocket gear F. Rt its end, the shaft E is fastened to the chassis by means of the floating bearing G in order to enable the springing of the wheel to take place. In Drawing Table 4, Figure B, the kinematic system for shock absorbing of the rear suspension is shown. The rear suspension consists of a plurality of elements, which operate as follows. In resting position, the rocker lever H is parallel to ground and is spaced apart from the suspension arm by a distance fl,which distance is controlled by means of the adjustable stop support L. Said rocker lever H is hinged in the fixed point E to the swinging arm. In this case, the main shock absorber C is under compression conditions, and the secondary shock absorber D is in neutral position, with Length N. The shock absorbers are respectively fastened at their ends in the points G and F, integral with the chassis, and the distance of the chassis from ground is B, directed downwards. The chassis tends to Lift, with distance B increasing, and with the shock abso-rber C being caused to extend to its maximum length. When this occurs, the rocker lever H is caused to rotate upwards by a value R' , and, by mechanical reaction, it compresses the shock absorber D, which gradually compensates for the extension of the shock absorber C. The ultimate consequence is that the arm of the suspension, and therefore the wheel, does not directly undergo the forces of reaction of the shock absorbers, but such reaction forces are applied through the rocker lever H, and the overall result is a progressive balancing of a vertical force and a horizontal force. For the purposes of the stability, the calculation of the distance between the front wheels -- i.e. , the track -- and of the distance between the front wheels and the rear wheel -- i.e. , the wheel base -- is important. In our specific case, the calculation is carried out by considering that the three-wheeler rests on ground on three points, and namely: - X : rear wheel ; - Y, Z : front wheels. Rfter assigning the track value, it wilt be enough to multiply said value by 1.58-1.60, preferably by 1.78 (a fixed coefficient) and the value of the wheel base will be obtained. Clearly, for any vehicle dimensions said value change, with them being proportional . to each other, with a constant ratio. In the specific case of engines with shaft transmission and one single arm, or when the engine is shifted relatively to the middle axis of the vehicle, with the side weight being hence unbalanced, the centre of the rear wheel should be shifted by the distance "X" in the same direction as of the excess weight. Such a finding is of basic importance, and constitutes an integral part of the other technical features of the vehicle according to the present invention, in that it enables the vehicle to turn to 6 the right and to the Left in the same way as it would do, if it had the weight it its exact middle. The top .cover shown in Drawing table 7 , Figure 9, which can be overturned laterally towards the side opposite to the entrance side, is equipped with a lock which enables it to be opened. Said lock is provided with a handle L installed inside the interior of the vehicle, and with an external handle H installed outside the vehicle. When said handles are rotated, they cause a lock pin F to enter the bore of the support G integral with the top cover, which is hence locked . In the specific case shown, when the handles are rotated downwards the top cover is opened and when they are rotated upwards, the top cover is Locked. Under emergency conditions, in order to make it possible the top cover to be totally removed, the vehicle is furthermore provided with a rapid-release safety lock, installed on the side opposite to the opening side. Said safety lock is equipped with two handles, i.e., an inner handle Cfl) and an external handle CB). Said Lock controls two rods CO and CE) , which lock the supports of the hinges around which the top cover rotates CD) . Said supports are fastened to the chassis and at their lower side they are locked by the rods CO and CE). The top cover is hinged onto the upper side of said supports by means of the pins CM) . When the .handles are rotated downwards, the rods CO and CE) come out from the bores, unlocking the supports, which are disengaged together with the top cover . From the above said Figures and from the hereinabove disclosure, the considerable vaLuable characteristics of practical and functional nature can be understood, which characterize the hereinabove disclosed improved three-wheeler; such valuable characteristics form, as a whole, an organic design which is the object of the present invention.

Claims: 1 β "IMPROVED THREE-WHEELER FDR TOURIST, SPORTING USE IN GENERRL" Claims 1. Improved three-wheeler for tourist and sporting use in general, characterized in that it has two front wheels acting as directional wheels, and one rear wheel acting as the driving wheel, with said rear wheel being connected with the engine through a single-arm swinging fork with a transmission of shaft-transmission type or of chain-transmission type, said three-wheeler being endowed with a considerably high stability supplied by the structure of the chassis, the arrangenent of the seats according to a tandem-arrangement, the particular value of the ratio of the wheel base value to the track value, the rear suspension equipped with two shock absorbers operating through a rocker lever, the reverse gear installed on one of the front wheels, and a Laterally overturning top cover with possibility of total disengagement from the vehicle. 2. Three-wheeler according to claim 1, characterized in that it has a multi-component bodywork comprising a front bonnet and a rear bonnet, bumpers, lower mudguard connection parts, overturning top cover, with said bonnets tilting in the same direction as the traveling direction. 3. Three-wheeler according to claim 1, characterized in that the structure of said chassis consists of metal section bars suitably welded and reinforced, with the two seats of the vehicle being arranged in tandem arrangement. 4. Three-wheeler according to claim 1, characterized in that a reverse-gear device is adopted which acts on one of said front wheels, by means of a chain transmission powered with electrical motor. 5. Three-wheeler according to claim 1, characterized in that the kinematic system of operation of said rear suspension comprises two shock absorbers, i.e. , a main shock absorber and a secondary, horizontal shock absorber, fastened, at one of their ends, onto the chassis, and at their other end to an "L"-shaped rocker Lever hinged onto the swinging arm of the suspension, with said shock absorbers compensating for each other in their operation above all during the acceleration, uniformly and proportionally discharging onto the hinge point of the rocker lever the contrast forces which are generated. 6. Three-wheeler according to claim 1, characterized in that for the calculation of the wheel base length, the track length, preliminary established, multiplied by 1.50:1.80, preferably by 1.70, determines the value of the wheel base, with said operation being completed with the calculation of the shift of the centre of the rear wheel from the middle of the vehicle, towards the same side as of asymmetrical loads possibly present, in order to compensate for unfavourable unbalancings directed towards the side of the excess load while the vehicle is running along a bend. 7. Three-wheeler according to claims 1 and 2 , characterized, in that it is equipped with a laterally overturning top cover, with a special device enabling the top cover hinges -- around which the top cover is overturned-- to be totally disengaged by means of purposely provided Locks to be used under particular emergency conditions and which are installed on the right-hand side or on the Left-hand side of the chassis, and are equipped with handles positioned outside the vehicle and inside the interior of the vehicle in order to consequetly operate. 6. Three-wheeler conceived within the scope of these interdependent features which, as their end result, make it possible a three-wheeler to be provided, which is endowed with exceptionally high characteristics of safety and stability for tourist and sporting use, according to the preceding claims, with the whole being as disclosed and illustrated in greater detail in the hereinabove disclosure and in the figures and in the drawings attached with the instant patent application .

Inventors: LAMATTINA CARLO, LAMATTINA, CARLO
Applicants: LAMATTINA CARLO, LAMATTINA, CARLO
Application year: 1989
Main classification: B62D61
IPC codes: B62D61, B62K5