WO2019167076A1

WO2019167076A1 - Helicon wormface gear set based steering system for reverse trikes

Info

Publication number: WO2019167076A1
Application number: PCT/IN2019/050168
Authority: WO
Inventors: Ravi Shankar Gautam
Original assignee: Ravi Shankar Gautam
Priority date: 2018-02-28
Filing date: 2019-02-28
Publication date: 2019-09-06

Abstract

This non-tilting steering system for reverse trikes uses spur-toothed duplex helicon wormface gear set mechanism. Central steerer rod, and steerer rod controlling the wheels are connected to duplex helicon wormface gear set. Each set consisting of two helicon worm gear meshingly simultaneously engaged with two face gears. Steerer rod at the center upon rotation, via handle, rotates a coaxial helicon worm gear which in turn rotates vertical pinion face gears engaged with it. Pinion face gear at the center then rotates transverse worm gear of the gear set mounted on the wheels via a transmission shaft which in turn rotates the horizontal pinion face gears attached to wheels, thus rotating the wheels. Second helicon worm gear in each gear set serves the purpose of coupling the steering action to other side of the face gears. This steering system can also used in a four wheeler.

Description

Title of Invention: Helicon Wormface Gear Set based Steering System for Reverse Trikes

Field of Invention

[01] Non-tilting steering system for reverse trike.

Background of Invention

[02] 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

[03] 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.

[04] Rotation motion is converted into translational motion which is then converted back to rotation motion

[05] Non-tilting steering mechanism for 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

[06] 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.

[07] 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.

[08] It has no externally moving parts.

Brief Description of Drawings

[09] [Fig. 1] and [Fig. 2] Side and Top view respectively of reverse trike with coupled torque steering system using helicon wormface gearset mechanism according to this invention.

[10] [Fig. 3] and [Fig. 4] Back and front view respectively of coupled torque steering system using helicon wormface gearset mechanism according to this invention.

[11] [Fig. 5] Steering mechanism according to this invention without head tubes.

[12] [Fig. 6] Front view of central, left and right helicon wormface gearset used as in steering mechanism according to this invention.

[13] [Fig. 7] Rear view of central, left and right helicon wormface gearset used as in steering mechanism according to this invention.

[14] [Fig. 8] Central, left and right helicon wormface gearset used as in steering mechanism without head tube arms according to this invention.

[15] [Fig. 9] and [Fig. 10] Assembled and exploded image of Central helicon wormface gear set. [16] [Fig. 11] Reverse trike with rotated front wheels due to steering action by steering system according to this invention.

Description of Embodiments

[17] As shown in [Fig. 1] and [Fig. 3], helicon wormface gear set 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

[18] As shown in [Fig. 3] central steering system (CSS) consists of central steering shaft

(CST), central head tube (CHT), central gear set (CGS) and central tubular cage (CTC).

[19] As shown in [Fig. 3] central steering shaft (CST) is a straight shaft, connected to a handle (HN) at its top, located on the center of the front part of reverse trike.

[20] 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).

[21] As shown in [Fig. 6], [Fig. 7], [Fig. 8], [Fig. 9] and [Fig. 10] central gear set (CGS)

consists of spur-toothed coupled duplex helicon gear. It consists of two coupled spur toothed cylindrical helicon worm gear (CHG1) and (CHG2) meshingly engaged with a pair of coaxially parallel face gear (CFG1) and (CFG2).

[22] As shown in [Fig. 9] and [Fig. 10] each of worm gears (CHG1) and (CHG2) is a vertical cylindrical worm gear with a spur gear of radius greater than that of said worm gear coaxially attached at each of its two circular faces. Worm gear (CHG1) has worm teeth on its upper half and worm gear (CHG1) has worm teeth on its lower half.

Worm gear (CHG1) coaxially fixedly connected with central steerer rod (CSR). Worm gear (CHG2) is located on the front side such that spur gears at its upper and lower end are meshingly coupled with spur gears at its upper and lower end respectively of (CHG1). [23] As shown in [Fig. 9] and [Fig. 10] 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 (CHG1), each face gears (CFG1) and (CFG2) are symmetrically placed with respect to worm gear, face teeth on face gears (CFG1) and (CFG2) are meshingly engaged with worm teeth of worm gear (CHG1) and (CHG2) at their left and right side respectively. Worm gears (CHG1) and (CHG2) lie on the rear and front half respectively of face gears (CFG1) and (CFG2) equidistant from the centers of face gears. 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).

[24] As shown in [Fig. 3] central tubular cage (CTC) consists of three C-shaped rods,

surrounding central gear set, with one C-shaped rod (CTC1) on the front side and one C- shaped rod (CTC2) on the right side, one C-shaped (CTC3) on left side of the central gear set. C-shaped rod (CTC1) lie on vertical forward plane and C-shaped rod (CTC2) and (CTC3) lie on vertical transverse plane. Upper end of C-shaped rods connected to upper section (CHT1) of head tube and lower end connected to lower section (CHT1) of central head tube (CHT).

Worm gear (CHG2) is coaxially journalled at it upper end and lower end to the rod extending from upper and lower arm of the C-shaped rod (CTC1) via ball bearings (CBB1) and (CBB2) respectively.

Central face gears (CFG1) and (CFG2) are held in place by steer transmission mechanism (STM).

Left wheel steering system

[25] As shown in [Fig. 3] left wheel steering system (LSS) consists of a wheel (LW), left steering fork (LSF), left head tube (LHT), left gear set (LGS) and left tubular cage (LTC).

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. [26] 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 central gear set with each section coaxially holding the central steering shaft using ball bearings.

[27] As shown in [Fig. 3], [Fig. 6], [Fig. 7] and [Fig. 8] left gear set (LGS) is structurally same as central gear set (CGS) with the difference in orientation in order to mount it on the left wheel steerer rod (LSR). Left gear set (LGS) consists of coupled spur-toothed duplex helicon gear set. It consists of two coupled spur-toothed cylindrical helicon worm gear (LHG1) and (LHG2) meshingly engaged with a pair of coaxially parallel face gear (LFG1) and (LFG2).

[28] Each of worm gear (LHG1) and (LHG2) is a transverse cylindrical worm gear with a spur gear of radius greater than that of said worm gear coaxially attached at each of its two circular faces. Worm gear (LHG1) has worm teeth on its right half and worm gear (LHG2) has worm teeth on its left half.

Worm gear (LHG1) is coaxially fixedly connected at its spur gear face to the left end of the left steering arm (LSA) of steering transmission mechanism (STM). Worm gear (LHG2) is located on the front side such that spur gears at its left and right end are meshingly coupled with spur gears at its left and right end respectively of (LHG1).

[29] Each of face gear (LFG1) and (LFG2) is a face gear same as (CFG1) or (CFG2). Face gears (LFG1) and (LFG2) are arranged and oriented such that they are coaxially parallel, face gear (LFG1) lies on the upper side of worm gear, face gear (LFG2) lies on the lower side of worm gear, axis of face gears (LFG1) and (LFG2) are perpendicular to that of worm gear (LHG1), each face gears (LFG1) and (LFG2) are symmetrically placed with respect to worm gear, face teeth of face gears (LFG1) and (LFG2) are meshingly engaged with worm teeth of worm gear (LHG1) and (LHG2) at their upper and lower side respectively. Worm gears (LHG1) and (LHG2) lie on the rear and front half respectively of face gears (LFG1) and (LFG2) equidistant from the centers of face gears. Face gear (LFG1) and (LFG2) are coaxially fixedly connected to steerer rod (LSR) of the left wheel.

[30] As shown in [Fig. 3] left tubular cage (LTC) consists of one C-shaped rod and four L- shaped rods, surrounding central gear set.

One C-shaped rod (LTC1) located on the front side of the left wheel steerer rod (LSR) lies on horizontal plane connected at its right end to the left head tube arm (TH1) of steer transmission mechanism (STM). Four L-shaped rods lies on vertical transverse plane.

One L-shaped rod (LTC2) is located on upper right side, one L-shaped rod (LTC3) is located on upper left side, one L-shaped rod (LTC4) is located on lower right side, one L- shaped rod (LTC5) is located on lower left side of the left wheel steerer rod (LSR). Upper end and lower end of (LTC5) and (LTC3) respectively are connected to outward arm of (LTC1). Upper end and lower end of (LTC4) and (LTC2) respectively are connected to left head tube of steer transmission mechanism (STM). Upper ends of (LTC2) and (LTC3) connected to upper section (LHT1) of left head tube. Lower ends of (LTC4) and (LTC5) connected to lower section (LHT2) of left head tube.

[31] Worm gear (LHG1) is coaxially journalled at it left end to the rod extending from upper and lower arm of the C-shaped rod (LTC1) via ball bearings (LBB1) and (LBB2) respectively. Worm gear (LHG2) is coaxially journalled at it left end and right end to the rod extending from the central tubular cage via ball bearing (LBB3).

Worm gear (CHG2) is coaxially journalled at it upper end and lower end to the rod extending from upper and lower arm of the C-shaped rod (CTC1) via ball bearing.

Right wheel steering system

[32] 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).

[33] 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. 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.

[34] As shown in [Fig. 3], [Fig. 6], [Fig. 7] and [Fig. 8] 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 helicon gear. It consists of two special type of cylindrical helicon worm gear (RHG1) and (RHG2) meshingly engaged with a pair of coaxially parallel face gear (RFG1) and (RFG2). [35] Worm gear (RHG1) and (RHG2) transverse cylindrical worm gear with a spur gear of radius greater than that of said worm gear coaxially attached at its left end and right end. Worm gear (RHG1) has worm teeth on its left half and worm gear (RHG1) has worm teeth on its right half.

Worm gear (RHG1) is coaxially fixedly connected at its spur gear face to the right end of the right steering arm (RSA) of steering transmission mechanism (STM). Worm gear (RHG2) is located on the front side such that spur gears at its right and left end are meshingly coupled with spur gears at its right and left end respectively of (RHG1).

[36] Each of face gear (RFG1) and (RFG2) is a face gear same as (CFG1) or (CFG2). Face gears (RFG1) and (RFG2) are arranged and oriented such that they are coaxially parallel, face gear (RFG1) lies on the upper side of worm gear, face gear (RFG2) lies on the lower side of worm gear, axis of face gears (RFG1) and (RFG2) are perpendicular to that of worm gear (RHG1), each face gears (RFG1) and (RFG2) are symmetrically placed with respect to worm gear, face teeth of face gears (RFG1) and (RFG2) are meshingly engaged with worm teeth of worm gear (RHG1) and (RHG2) at their upper and lower side respectively. Worm gears (RHG1) and (RHG2) lie on the rear and front half respectively of face gears (RFG1) and (RFG2) equidistant from the centers of face gears. Face gear (RFG1) and (RFG2) are coaxially fixedly connected to steerer rod (RSR) of the right wheel.

[37] Right tubular cage (RTC) consists of one C-shaped rod and four L-shaped rods,

surrounding central gear set.

One C-shaped rod (RTC1) located on the front side of the right wheel steerer rod (RSR) lies on horizontal plane connected at its left end to the right head tube arm (TH1) of steer transmission mechanism (STM). Four L-shaped rods lies on vertical transverse plane.

One L-shaped rod (RTC2) is located on upper left side, one L-shaped rod (RTC3) is located on upper right side, one L-shaped rod (RTC4) is located on lower left side, one L- shaped rod (RTC5) is located on lower right side of the right wheel steerer rod (RSR). Upper end and lower end of (RTC5) and (RTC3) respectively are connected to outward arm of (RTC1). Upper end and lower end of (RTC4) and (RTC2) respectively are connected to right head tube of steer transmission mechanism (STM). Upper ends of (RTC2) and (RTC3) connected to upper section (RHT1) of right head tube. Lower ends of (RTC4) and (RTC5) connected to lower section (RHT2) of right head tube. [38] Worm gear (RHG1) is coaxially journalled at it right end to the rod extending from upper and lower arm of the C-shaped rod (RTC1) via ball bearings (RBB1) and (RBB2) respectively. Worm gear (RHG2) is coaxially journalled at it right end and left end to the rod extending from the central tubular cage via ball bearing (RBB3).

Steer Transmission Mechanism

[39] Central steering system is coupled with left wheel steering system and right wheel

steering system via steer transmission mechanism (STM). As shown in [Fig. 6], [Fig. 7] and [Fig. 8] 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 (RHG1) and one transverse shaft (TS2) on left side coaxially connecting central face gear (CFG1) and to left wheel worm gear (LHG1) 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.

[40] Head tube arms on the left side and right side are connected at their rear side to upper section (CHT1) of central head tube via two rods left top tube arm (LTTA) and right top tube arm (RTTA) respectively.

Steer operation

[41] On rotation in clockwise direction, handle causes which in turn worm gear (CHG1) to rotate clockwise direction causes worm gear (CHG1) to rotate anticlockwise direction and therefore causes face gears (CFG1) and (CFG2) and hence causes helicon worm gears (LHG1) and (RHG1) to rotate clockwise direction with respect to left steer transmission arm (TS1). Rotation of worm gears (LHG1) and (RHG1) causes helicon worm gears (LHG2) and (RHG2) ) to rotate anticlockwise direction with respect to left steer transmission arm (TS1) and thus causing face gears (LFG1), (LFG2), (RFG1) and (RFG2) to rotate in clockwise direction and thus steering the wheels in clockwise direction.

Claims

[Claim 1] Coupled torque steering system comprising helicon wormface gear set based central steering system, left wheel steering system, right wheel steering system and steer transmission mechanism.

[Claim 2] Right wheel steering system and left wheel steering system claimed in [Claim 1] are located on the right and left side respectively on the front part of the reverse trike with each of them comprising a wheel, steering fork, head tube, tubular cage and helicon wormface gear set wherein

wheel is preferably of diameter less than the height of seat;

steering fork is a rigid/ suspension fork with steerer rod connected at its crown and fork blades at their ends holding the wheel at the ends of its axle; head tube consists of two vertical tubes separated by distance of bevel-pinion gear set encasing the steerer rod with the help of ball bearings;

helicon wormface gear set consists of two coaxially parallel face gears, two tranverse spur-toothed helicon worm gear;

each face gear with faces in the vertical direction and vertically inward face have spiral tooth;

spur-toothed worm gear is a helicon worm gear with spur gear coaxially attached at each of its circular face;

tubular cage consists of one C-shaped rods and four L-shaped rods which directly or indirectly holds the worm gears and face gears in their designated places.

[Claim 3] Helicon wormface gear set for the wheels mentioned in [Claim 2] is configured such that

upper and lower face gears are coaxially fixedly connected to the steerer rod; two spur-toothed worm gears are oriented in transverse direction and lie between the spur-toothed face gear with one gear lying on the rear half and another on the front half of horizontal face gears with their spur teeth of one worm gear me shingly engaged with the spur teeth of another worm gear;

rear side spur toothed worm gear coaxial attached at its transversely inward end to the transversely outward end of the steer transmission arm of steer transmission mechanism;

front side worm gear is coaxially journalled at both of its ends to a horizontal rod extending from tubular cage via ball bearing; rear side worm gear is coaxially journalled at its transversely outward end to a horizontal rod extending from tubular cage via ball bearing.

[Claim 4] Tubular cage for the front wheels are configured such that

one C-shaped rod lying on horizontal plane located on the front side of the corresponding wheel steerer rod connected at its transversely inward end to corresponding side head tube arm of steer transmission mechanism;

all four L-shaped rod for tubular cage on each side lie on transverse vertical plane;

L-shaped rods located in upper transversely inward side and lower transversely inward side of the steerer rod of the corresponding wheel connects upper section and lower section respectively of the head tube of the wheel to the corresponding side head tube arm of steer transmission mechanism;

L-shaped rods located in upper transversely outward side and lower transversely outward side of the steerer rod of the corresponding wheel connects upper section and lower section respectively of the head tube of the wheel to the transversely outward side arm of corresponding C-shaped arm;

[Claim 5] Central steering system claimed in [Claim 1] located on centre of the front part of the reverse trike, comprises, central steering shaft, central head tube, central tubular cage and central helicon wormface gear set wherein

central steering shaft is a straight shaft with handle at its top ;

central head tube consists of two vertical tubes as upper section and lower section separated by distance of central bevel-pinion gear set encasing the central steering shaft with the help of ball bearings with upper section connected at its rear side to the top tube of the reverse trike and lower section at its rear side is connected to the down tube of the reverse trike;

central helicon wormface gear set consists of two coaxially parallel face gears oriented in transverse direction, two vertical spur-toothed helicon worm gear; each face gear with faces oriented in transverse direction and transversely inward face have spiral tooth;

spur-toothed helicon worm gear is a helicon worm gear with spur gear coaxially attached at each of its circular face;

tubular cage consists of three C-shaped rods which directly or indirectly holds the worm gears and face gears in their designated places.

[Claim 6] Central helicon wormface gear set mentioned in [Claim 2] is configured such that left spur-toothed face gear are coaxially attached at its left face to the right end left steer arm of steer transmission mechanism and right spur-toothed face gear are coaxially attached at its right face to the left end of the left steer arm of steer transmission mechanism;

two spur-toothed worm gears are oriented in vertical direction and lie between the spur-toothed face gear with one gear lying on the rear half and another on the front half of horizontal face gears with their spur teeth of one worm gear me shingly engaged with the spur teeth of another worm gear;

rear side spur toothed worm gear coaxial attached on the upper side to the central steerer rod;

front side worm gear is coaxially journalled at both of its ends to a vertical rod extending from tubular cage via ball bearing;

rear side worm gear is coaxially journalled at its bottom end to a vertical rod extending from tubular cage via ball bearing.

[Claim 7] Central tubular cage is configured such that

it has one C-shaped rod on front and one on right side and one on left side of the steerer rod with their and lower ends attached to upper and lower section of the central head tube;

upper arm and lower arm of the front C-shaped rods holds the front side worm gear via coaxial vertical rods coaxially attached with ball bearing.

[Claim 8] Central steering system is coupled with left wheel steering system and right wheel steering system via steer transmission mechanism mentioned in [Claim 1]

[Claim 9] Steer transmission mechanism mentioned in [Claim 1] and [Claim 8] consists of two steer transmission arms each of which is a transverse straight shaft, wherein one transmission arm coaxially connects right side face of transversely oriented right side central face gear, mentioned in [Claim 3], to left face of transversely oriented right wheel rear side helicon worm gear mentioned in [Claim 2];

one transmission arm coaxially connects left side face of transversely oriented left side central face gear mentioned in [Claim 3] to right face of transversely oriented left wheel rear side helicon worm gear mentioned in [Claim 2];

each transmission arm is coaxially encased in head tube arm, which is straight tube, via ball bearings; head tube arms on the left side and right side are connected at their rear side to front side of upper section of central head tube via appropriately bent rods. [Claim 10] Handle claimed in [Claim 2] is preferably round handle with its center connected to the upper end of central steering shaft claimed in [Claim 3], is located above the front end of the top tube of reverse trike at a height around the height of seat.