FIELD OF INVENTION
Non-tilting steering system for reverse trike.
BACKGROUND OF INVENTION
It is obvious that reverse trikes are more safe and stable than bikes and conventional trikes. Reverse trikes have many mechanical advantages over conventional trikes which include stability, traction in uphills and steerability. But providing an efficient steering mechanism for reverse trikes is a challenge. In recent past many models of reverse trikes have come up in the public domain offering tilting steering system. Tilting steering system has many issues which includes traction as well as ground clearance while cornering around a turn. Non-tilting steering system for reverse trikes have drawn little attention as it is understood by majority of folks that rack and pinion steering mechanism used in cars is sufficient for the purpose. But it has its own issues which includes big reduction ratio and too complex mechanism to handle on a trike. Non-tilting steering system is provided in Newton reverse trikes. It employs pitman arm to swing the kingpin attached to spindle mounted on each of the two front steer wheels.
Technical Problem
Steering mechanism of reverse trike or four wheelers have externally moving parts in the form of steer transmission rods. It may be huge disadvantage in case of uneven land mass caused during snow fall.
Rotation motion is converted into translational motion which is then converted back to rotation motion
Non-tilting steering mechanism in Newton reverse trike applies the steering torque on the two wheels either from the front side of the head tube or rear side of the head tube due to which force gets exerted on the head tube rearward or forward direction respectively, thus making it difficult to operate as compared to steering system for a bicycle. In bicycles steering torque applied on the wheel is symmetric along the head tube.
SUMMARY OF INVENTION
One of our objective is to provide steering system for reverse trike which is as ergonomic to operate as that of a bicycle.
To achieve this objective steering system for reverse trike is designed such that two front wheels can be transversely rotated using coupled torque. Steering torque is applied on each of the front wheels symmetrically on both ends of the axle and symmetrically on front and rear side of the steerer rods, thereby providing easy and stable maneuverability to the steering system. Head tube is proportional to the length of steerer rod to provide sturdiness to steerer rod.
Wheels can be turned by 360 degree.
Rotation steering action at the handle is transmitted as steering action on the wheel through rotation motion and is not converted into translational motion as intermediate phase.
It has no externally moving parts.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 and FIG. 2 Side and Top view respectively of reverse trike with wormface gearset based coupled torque steering system according to this invention.
FIG. 3 and FIG. 4 Back and front view respectively of wormface gearset based coupled torque steering system according to this invention.
FIG. 5 Steering mechanism according to this invention without head tubes.
FIG. 6 Central, left and right wormface gearset used as in steering mechanism according to this invention.
FIG. 7 Central, left and right wormface gearset used as in steering mechanism without head tube arms according to this invention.
FIG. 8 Blown out image of central wormface gearset
FIG. 9 Blown out image of left wheel wormface gearset
FIG. 10 Reverse trike with rotated front wheels due to steering action by steering system according to this invention.
DESCRIPTION OF EMBODIMENTS
As shown in [FIG. 1] and [FIG. 3], wormface gearset based coupled torque steering system for reverse trike (1) with top tube (TT) and down tube (DT), according to this invention comprises central steering system (CSS), left wheel steering system (LSS), right wheel steering system (RSS), steer transmission mechanism (STM), steering support mechanism (SSM).
Central Steering System
As shown in [FIG. 3] central steering system consists of central steering shaft, central head tube (CHT), central gear set (CGS) and central tubular cage (CTC).
As shown in [FIG. 3] central steering shaft (CST) is a straight shaft, connected to a handle at its top, located on the center of the front part of reverse trike.
As shown in [FIG. 3] central head tube (CHT) is a set of two sections of vertical tubes, upper section (CHT1) and lower section (CHT2) separated by distance equal to the height of central gear set with each section coaxially holding the central steering shaft using ball bearings and upper section on its rear attached to top tube (TT) and lower section attached on its rear side to down tube (DT).
As shown in [FIG. 6] and [FIG. 8] central gear set (CGS) consists of special type of coupled duplex wormface gear. It consists of spur-toothed worm gear (CWG) meshingly engaged with a pair of coaxially parallel spur-toothed face gear (CFG1) and (CFG2) which in turn is meshingly engaged with three spur gears (CSG1), (CSG1) and (CSG3).
As shown in [FIG. 3] worm gear (CWG) coaxially fixedly connected with central steerer rod (CSR) is cylindrical worm gear with a spur gear of radius greater than or equal to that of said worm gear coaxially attached at its upper end with number of worm teeth being equal to that of its spur teeth. Each of face gears (CFG1) and (CFG2) is a face gear coaxially attached at its vertically upward circular face to a spur gear of face radius greater than equal to that of said face gear with the number of face teeth being equal to the number of its spur teeth.
As shown in [FIG. 3], [FIG. 6] and [FIG. 8] face gears (CFG1) and (CFG2) are arranged and oriented such that they are coaxially parallel, face gear (CFG1) lies on the left side of worm gear, face gear (CFG2) lies on the right side of worm gear, axis of face gears (CFG1) and (CFG2) are perpendicular to that of worm gear (CWG), each face gears (CFG1) and (CFG2) are symmetrically placed with respect to worm gear, face teeth on upper half of face gears (CFG1) and (CFG2) are meshingly engaged with worm teeth of worm gear at its left and right side respectively, spur teeth of face gears (CFG1) and (CFG2) are meshingly engaged with spur teeth of worm gear (CWG) at its left and right side respectively. Face gear (CFG1) at its outward side is fixedly coaxially connected to right end of left steering arm (LSA) of steer transmission mechanism (STM). Face gear (CFG2) at its outward side is fixedly coaxially connected to left end of right steering arm (RSA) of steer transmission mechanism (STM).
As shown in [FIG. 3], [FIG. 6] and [FIG. 8] spur gears (CSG1), (CSG2) and (CSG3) are placed on front, bottom and rear point of face gears respectively such that each spur gear is equidistant from both the face gears, axis of spur gears lie on the plane perpendicular to the axis of face gears, spur teeth of spur gears are meshingly engaged with spur teeth of face gears. Bottom spur gear (CSG2) is coaxially mounted on steering shaft via ball bearing so that it is free to rotate.
As shown in [FIG. 3], central tubular cage (CTC) consists of two C-shaped rods and four L-shaped rods, surrounding central gear set, with one C-shaped rod on the front side of central gear set with its upper and lower ends connected to upper section (CHT1) and lower section (CHT2), respectively, of central head tube; one C-shaped rod on the rear side of central gear set with its upper and lower ends connected to upper section (CHT1) and lower section (CHT2), respectively, of central head tube; one L-shaped on upper right side of central gear set with its ends connected to right steer arm of steer transmission mechanism and upper section (CHT1) of central head tube; one L-shaped rod lower right side of central gear set with its ends connected to right steer arm of steer transmission mechanism and lower section (CHT2) of central head tube; one L-shaped upper left side of central gear set with its ends connected to left steer arm of steer transmission mechanism and upper section (CHT1) of central head tube; and one L-shaped rod on lower left side of central gear set with its ends connected to left steer arm of steer transmission mechanism and lower section (CHT2) of central head tube.
As shown in [FIG. 3], [FIG. 6] and [FIG. 8] pinion spur gears on front and rear side (CSG1) and (CSG3) are coaxially connected at their outer side to the rod extending from the central tubular cage via ball bearings (CBB1), (CBB2) and (CBB3) respectively.
As shown in [FIG. 3], [FIG. 6] and [FIG. 8] central face gears (CFG1) and (CFG2) are held in place by steer transmission mechanism (STM).
Left Wheel Steering System
As shown in [FIG. 3] and [FIG. 5] left wheel steering system consists of a wheel (LW), left steering fork (LSF), left head tube (LHT), left gear set (LGS) and left tubular cage (LTC).
As shown in [FIG. 3] and [FIG. 5] left wheel steering fork (LSF) is a rigid/suspension fork with steerer rod (LSR) with fork blades at their ends holding the wheel (LW) at the ends of its axle.
As shown in [FIG. 3] and [FIG. 5] left head tube (LHT) is a set of two sections of vertical tubes, upper section (LHT1) and lower section (LHT2) separated by distance equal to the height of left wheel gear set (LGS) with each section coaxially holding the central steering shaft using ball bearings.
As shown in [FIG. 6] and [FIG. 9] left gear set (LGS) is structurally same as central gear set (CGS) with the difference in orientation in order to mount is mounted it on the left wheel steerer rod (LSR). Left gear set (LGS) consists of special type of coupled duplex wormface gear. It consists of spur-toothed worm gear (LWG) meshingly engaged with a pair of coaxially parallel spur-toothed face gear (LFG1) and (LFG2) which in turn is meshingly engaged with three spur gears (LSG1), (LSG1) and (LSG3).
As shown in [FIG. 6] and [FIG. 9] worm gear (LWG) is a cylindrical worm gear same as (CWG) and is coaxially fixedly connected at its spur gear face to the left end of the left steering arm (LSA) of steering transmission mechanism (STM).
As shown in [FIG. 3], FIG. 6 and [FIG. 9] each of face gear (LFG1) and (LFG2) is a face gear same as (CFG1) or (CFG2). Worm gear (LWG) and two face gears (LFG1) and (LFG2) are arranged and oriented such that worm gear (LWG) is transversely oriented and is located right side of left wheel steerer rod (LSR) with its spur face coaxially facing the central face gear (CFG1), two face gears (LFG1) and (LFG2) are coaxially parallel, face gear (LFG1) lies on the upper side of worm gear and is coaxially mounted on left wheel steerer rod (LSR) via ball bearing, face gear (LFG2) lies on the lower side of worm gear (LWG) and is coaxially fixedly connected to the left wheel steerer rod (LSR), axis of face gears (LFG1) and (LFG2) are perpendicular to that of worm gear (LWG), each face gears (LFG1) and (LFG2) are symmetrically placed with respect to worm gear, face gears (LFG1) and (LFG2) are meshingly engaged with worm gear at its upper and lower side respectively on the right side of left wheel steerer rod (LSR), spur teeth of face gears (LFG1) and (LFG2) are meshingly engaged with spur teeth of worm gear (LWG) at its upper and lower side respectively.
As shown in [FIG. 3], [FIG. 6] and [FIG. 9] spur gears (LSG1), (LSG2) and (LSG3) are placed on front, left and rear end point of face gears respectively such that each spur gear is equidistant from both the face gears (LFG1) and (LFG2), axis of spur gears lie on the plane perpendicular to the axis of face gears, spur teeth of spur gears are meshingly engaged with spur teeth of face gears (LFG1) and (LFG2).
As shown in [FIG. 1] and [FIG. 3], left tubular cage (LTC) consists of three C-shaped rods and two L-shaped rods, surrounding left wheel gear set, with one C-shaped rod on the front side of central gear set with its upper and lower ends connected to upper section (LHT1) and lower section (LHT2), respectively, of left wheel head tube; one C-shaped rod on the rear side of left wheel gear set with its upper and lower ends connected to upper section (LHT1) and lower section (LHT2), respectively, of left wheel head tube; one C-shaped rod on the left side of left wheel gear set with its upper and lower ends connected to upper section (LHT1) and lower section (LHT2), respectively, of left wheel head tube; one L-shaped on upper right side of left wheel gear set with its ends connected to right steer arm of steer transmission mechanism and upper section (LHT1) of left wheel head tube; one L-shaped rod lower right side of left wheel gear set with its ends connected to right steer arm of steer transmission mechanism and lower section (LHT2) of left wheel head tube.
As shown in [FIG. 3] pinion spur gears on front and rear side (LSG1), (LSG2) and (LSG3) are coaxially journalled at their outer side to the rod extending from the left tubular cage (LTC) via ball bearings (LBB1), (LBB2) and (LBB3) respectively.
Right Wheel Steering System
As shown in [FIG. 3] and [FIG. 5] Right wheel steering system consists of a wheel (RW), right steering fork (RSF), right head tube (RHT), right gear set (RGS) and right tubular cage (RTC).
As shown in [FIG. 3] and [FIG. 5] right wheel steering fork (RSF) is a rigid/suspension fork with steerer rod (RSR) with fork blades at their ends holding the wheel (RW) at the ends of its axle.
As shown in [FIG. 3] and [FIG. 5] right head tube (RHT) is a set of two sections of vertical tubes, upper section (RHT1) and lower section (RHT2) separated by distance equal to the height of central gear set with each section coaxially holding the central steering shaft using ball bearings.
As shown in [FIG. 3] and [FIG. 6] right gear set (RGS) is structurally same as central gear set (CGS) with the difference in orientation in order to mount is mounted it on the right wheel steerer rod (RSR). Right gear set (RGS) consists of special type of coupled duplex wormface gear. It consists of spur-toothed worm gear (RWG) meshingly engaged with a pair of coaxially parallel spur-toothed face gear (RFG1) and (RFG2) which in turn is meshingly engaged with three spur gears (RSG1), (RSG1) and (RSG3).
As shown in [FIG. 3] and [FIG. 6] worm gear (RWG) is a cylindrical worm gear same as (CWG) and is coaxially fixedly connected at its spur gear face to the right end of the right steering arm (RSA) of steering transmission mechanism (STM).
As shown in [FIG. 3], [FIG. 6] and [FIG. 9] each of face gear (RFG1) and (RFG2) is a face gear structurally same as (CFG1) or (CFG2). Worm gear (RWG) and two face gears (RFG1) and (RFG2) are arranged and oriented such that worm gear (RWG) is transversely oriented and is located left side of right wheel steerer rod (RSR) with its spur face coaxially facing the central face gear (CFG2), two face gears (RFG1) and (RFG2) are coaxially parallel, face gear (RFG1) lies on the upper side of worm gear and is coaxially mounted on right wheel steerer rod (LSR) via ball bearing, face gear (RFG2) lies on the lower side of worm gear (RWG) and is coaxially fixedly connected to the right wheel steerer rod (RSR), axis of face gears (RFG1) and (RFG2) are perpendicular to that of worm gear (RWG), each face gears (RFG1) and (RFG2) are symmetrically placed with respect to worm gear, face gears (RFG1) and (RFG2) are meshingly engaged with worm gear at its upper and lower side respectively on the left side of right wheel steerer rod (RSR), spur teeth of face gears (RFG1) and (RFG2) are meshingly engaged with spur teeth of worm gear (RWG) at its upper and lower side respectively.
As shown in [FIG. 3] and [FIG. 6] spur gears (RSG1), (RSG2) and (RSG3) are placed on front, right and rear end point of face gears respectively such that each spur gear is equidistant from both the face gears, axis of spur gears lie on the plane perpendicular to the axis of face gears, spur teeth of spur gears are meshingly engaged with spur teeth of face gears.
Right tubular cage (RTC) consists of three C-shaped rods and two L-shaped rods, surrounding right wheel gear set, with one C-shaped rod on the front side of central gear set with its upper and lower ends connected to upper section (RHT1) and lower section (RHT2), respectively, of right wheel head tube; one C-shaped rod on the rear side of right wheel gear set with its upper and lower ends connected to upper section (RHT1) and lower section (RHT2), respectively, of right wheel head tube; one C-shaped rod on the right side of right wheel gear set with its upper and lower ends connected to upper section (RHT1) and lower section (RHT2), respectively, of right wheel head tube; one L-shaped on upper right side of right wheel gear set with its ends connected to right steer arm of steer transmission mechanism and upper section (RHT1) of right wheel head tube; one L-shaped rod lower right side of right wheel gear set with its ends connected to right steer arm of steer transmission mechanism and lower section (RHT2) of right wheel head tube.
As shown in [FIG. 3], [FIG. 5] and [FIG. 6] pinion spur gears on front and rear side (RSG1), (RSG2) and (RSG3) are coaxially journalled at their outer side to the rod extending from the right tubular cage (RTC) via ball bearings (RBB1), (RBB2) and (RBB3) respectively.
Steer Transmission Mechanism
As shown in [FIG. 3], [FIG. 6] and [FIG. 7] central steering system is coupled with left wheel steering system and right wheel steering system via steer transmission mechanism (STM). Steer transmission mechanism (STM) consists of two transverse straight shafts, one transverse shaft (TS1) on right side coaxially connecting central face gear (CFG2) to right wheel worm gear (RWG) and one transverse shaft (TS2) on left side coaxially connecting central face gear (CFG1) and to left wheel worm gear (LWG) of the central gear set. Transverse shaft (TS1) and (TS2) are coaxially encased in straight tubes, right head tube arm (TH1) and left head tube arm (TH2) respectively, via ball bearings.
As shown in [FIG. 3] head tube arms on the left side and right side are connected at their rear side to top tube via rods left top tube arm (LTTA) and right top tube arm (RTTA) respectively.
Steer Operation
On rotation in clockwise direction, handle causes worm gear (CWG) to rotate clockwise direction which in turn causes face gear causes face gears (CFG1) and (CFG2) and hence causes worm gears (LHG1) and (RHG1) to rotate clockwise direction and anticlockwise direction respectively with respect to left steer transmission arm (TS1). Rotation of worm gears (LHG1) and (RHG1) causes face gears (LFG2) and (RFG2) to rotate in clockwise direction and thus steering the wheels in clockwise direction.
Spur gears in the central gear set, left wheel gear set and right wheel gear set are auxiliary gears which help to couple the steering action of worm gears.
Patent Application
20200398925
