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Title:
BICYCLE WITH BILATERALLY MULTICHAIN DRIVE MECHANISM AND FORWARD MOTION PROMOTING REAR WHEEL SUPPORT
Document Type and Number:
WIPO Patent Application WO/2019/167084
Kind Code:
A1
Abstract:
This patent discloses bilaterally mounted multi-axis multi-chain drive mechanism for bicycles facilitating application of driving force on larger area. It consists of pair of drive assemblies with each consisting of a special type of planetary gearbox in which plurality of suitably modified planetary gears and a gear ring are arranged in such a way that gear ring can be rotated via pedal which in turn rotates planetary gears along its direction of rotation. Each planetary gear at its center is attached to coaxially parallel chain crank which in turn meshes with a separate sprocket wheel mounted on rear wheel hub. Larger radius of the gear ring than planetary gears accounts for gear ratio. Drive mechanism doesn't come in contact with clothing of the rider. Seat stays are replaced by rear wheel support mechanism which facilitates better bicycle kinematics.

Inventors:
GAUTAM, Ravi Shankar (RajendrapathNear Kabir Paan shop, Nai Godam, Gaya 1, 823001, IN)
Application Number:
IN2019/050179
Publication Date:
September 06, 2019
Filing Date:
March 01, 2019
Export Citation:
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Assignee:
GAUTAM, Ravi Shankar (RajendrapathNear Kabir Paan shop, Nai Godam, Gaya 1, 823001, IN)
International Classes:
B62M9/10; B62M11/14; B62M11/18; F16H3/66
Foreign References:
US6852060B12005-02-08
US20100298084A12010-11-25
Download PDF:
Claims:
Claims

[Claim 1] Bicycle having bilateral sided drive mechanism which includes plurality of chain cranks at the front part each having different axis of rotation mounted on a plane coplanar to the frame of bicycle, plurality of sprocket ratchet wheels at the rear wheel and plurality of endless chains meshing sprocket ratchet wheel with coplanar chain crank, and allows the rider to rotate all the chain cranks simultaneously by applying rotatory force via pedal, thereby rotating all the sprocket ratchet wheels simultaneously and generating rotatory motion on the rear wheel and a forward motion promoting rear wheel support mechanism.

[Claim 2] Drive mechanism, as claimed in [Claim 1], comprising

front part which includes a pair of drive assemblies each having plurality of chain cranks, multipoint inter-drive-assembly-coupling mechanism, a pair of pedals, a pair of drive enclosure brackets each of which secure a drive assembly to the frame via bracket support,

rear part which includes rear wheel assembly and

plurality of endless chains coupling the front and rear part.

[Claim 3] Rear wheel assembly, as claimed in [Claim 2], comprises a wheel at the rear part of bicycle with plurality of sprocket ratchet wheels coaxially mounted on each side of its hub.

[Claim 4] Each drive assembly, as claimed in [Claim 2], comprises

a special type of epicyclic gear which we refer as pivoted-slewing-bearing-epicyclic- gear, with plurality of chaincranks integrated to it.

[Claim 5] Pivoted-slewing-bearing-epicyclic-gear, as claimed in [Claim 4], comprises a

circular plate called as carrier plate having plurality of spur gears including planetary gears, a sun gear, satellite gears and far planet gears journalled to it and connected along its circumference to an internal toothed slewing bearing via U- shaped pegs, in arrangement such that

center of sun gear is at the center of the carrier plate,

carrier plate at its side containing sun gear is attached at its periphery to the outer ring of the said slewing bearing over-bridging gear ring with the help of U- shaped pegs such that slewing bearing is coaxial with Sun gear, each of planetary gears which are spur gears of equal radii is meshingly engaged with sun gear and gear ring of the slewing bearing, each satellite gear is meshingly engaged with two adjacent planetary gears and a far planet gear,

each far planet gear is meshingly engaged with gear ring of the said slewing bearing and a satellite gear,

and a pivot plate, which is an eared circular plate with radius equal to the average of outer and inner radius of gear ring, is attached at its rim to the gear ring at its outer side and is coaxially journalled to the outer side of the carrier plate.

[Claim 6] Pivoted-slewing-bearing-epicyclic gear, described in [Claim 5], is constrained to follow the conditions that

number of planetary gears, satellite gears and far planet gears used are three radius of planetary gears being greater than the radius of sun gear, satellite gears and far planet gears;

satellite gears are of equal radii and far planet gears are of equal radii;

centers of three planetary gears forms an equilateral triangle with its circumcenter being center of sun gear;

centers of satellite gears and far planet gears falls on the perpendicular bisectors of the said triangle.

[Claim 7] Each of the planetary gears of pivoted-slewing-bearing-epicyclic gear, claimed in

[Claim 5], is attached to a coaxially parallel chain crank via a metal peg such that each chain crank is coplanar to one of the sprocket ratchet wheel mounted on rear wheel hub.

[Claim 8] Each chain crank claimed in [Claim 7] meshes with a coplanar sprocket ratchet wheel mounted on rear wheel hub via an endless chain claimed in [Claim 2]

[Claim 9] Multipoint inter-drive-assembly-coupling mechanism, mentioned in [Claim 2], consists of plurality of inter-drive-assembly coupling shafts each of which is a straight shaft coaxially connecting center of chain cranks on drive assembly on left side to the center of a coaxially parallel chain crank on the other drive assembly on the right side.

[Claim 10] Drive bracket support, claimed in [Claim 2] is a vertical rectangular metal plate, coplanar with bicycle frame, is attached at its upper side to bottom end of down tube and seat tube and have ball bearings mounted on its plane each of which coaxially houses middle part of a inter-drive-assembly-coupling shaft, described in [Claim 9]

[Claim 11] Each of the pair of drive enclosure bracket, as claimed in [Claim 2], comprises an enclosure which is in the form of cylinder, with its axis being perpendicular to the frame of the bicycle, attached at its inner side rim to drive bracket support, explained in [Claim 10], vertically sliced to have a rectangular opening facing rear part of the bicycle, with cylinder being of radius equal to the outer radius of slewing bearing and length approximately equal to distance between frame and a carrier plate, with opening big enough to provide space for the motion of front- rear-coupling shafts,

a circular annular plate, attached to outer side rim of the said enclosure, to which outer ring of drive assembly is fastened, and

a metal bar referred to as shaft stays connecting said rear part of circular annular plate to outer end of main bearing shaft of rear crank shaft explained in claim[3]

[Claim 12] A pedal, claimed in [Claim 2] is pivoted to the periphery of the pivot plate, claimed in [Claim 5], at its outer side.

[Claim 13] Carrier plates, claimed in [Claim 5], can be fixed to be stationary by directly

connecting it to the drive bracket support, described in [Claim 10], via rods.

[Claim 14] Rear wheel support mechanism claimed in [Claim 1], comprises rear bracket, rear bracket support and a pair of hub fasteners, one on right side of rear wheel and one on left side of rear wheel.

[Claim 15] Rear bracket comprises two V-shaped planar trusses parallel to the rear wheel with one truss located on right side of rear wheel and other located on left side of rear wheel.

[Claim 16] Rear bracket support, which connects upper ends of both the V-shaped planar trusses of rear bracket to the bicycle frame, comprises two forward slanting A-shaped trusses and a tube extending rearwardly from the rear end of top tube wherein

one A-shaped truss located on rear side of the seat tube is connected at its angled upper end to rear side of the said tube;

other truss located on front side of the seat tube is connected at its angled upper end to the top tube;

bottom ends of two arms of front and rear A-shaped trusses are connected to upper front ends and upper rear ends, respectively of rear bracket;

[Claim 17] Each of V-shaped planar trusses, mentioned in [Claim 15], comprises two coplanar

V-shaped rods arranged one behind the other parallel to the rear wheel and a V- shaped peg located on corresponding side of the rear wheel wherein

each of V-shaped rods have acute angle bend facing the forward direction; angled corners of V-shaped rods lies on the upper rear side of axle of the rear wheel;

angled corner of front side V-shaped rod is located vertically higher than that of rear side V-shaped rod;

each of V-shaped rods have one arm extending downwards with their bottom ends fixedly connected to the main bearing shaft of the rear crank shaft on the corresponding side of the rear wheel;

above mentioned downward extending rods may be suspension or rigid rod according to requirement;

upper ends of rear and front V-shaped trusses are connected to bottom ends of corresponding side arms of rear and front A-shaped trusses respectively;

V-shaped peg is attached at its angled corner to the angled corner of front side V- shaped rod at its rearward side and one arm as a rearward extension of lower arm of front side V-shaped rod with its upper end attached to upper arm of rear side V-shaped rod and other arm as a rearward extension of upper arm of front V-shaped rod with its lower end attached to lower arm of rear side V-shaped rod.

[Claim 18] In one possible variation of the drive mechanism claimed in [Claim l]-[Claim 13], wherein gear ring is only peripherally pivoted, pedals are directly pivoted on the outer side of the gear ring.

[Claim 19] In another possible variation of the drive mechanism claimed in [Claim l]-[Claim

13], wherein gear ring is only axially pivoted, carrier plate at its periphery is connected to drive bracket via U-shaped pegs over-bridging gear ring.

AMENDED CLAIMS

received by the International Bureau on 16 July 2019 (16.07.2019)

[Claim 1] Bicycle having bilateral sided multi-chain multi-axis drive mechanism providing localized gear ratio and protection to rider clothing from gears and chains, comprising plurality of chain cranks at the front part each having different axis of rotation mounted on a plane coplanar to the frame of bicycle, plurality of sprocket ratchet wheels at the rear wheel and plurality of endless chains meshing sprocket ratchet wheel with coplanar chain crank, and allows the rider to rotate all the chain cranks simultaneously by applying rotatory force via pedal, thereby rotating all the sprocket ratchet wheels simultaneously and generating rotatory motion on the rear wheel and a forward motion promoting rear wheel support mechanism allowing bilateral rear suspension.

[Claim 2] Multi-chain multi-axis drive mechanism, as claimed in [Claim 1], comprising

front part which includes a pair of drive assemblies each having plurality of chain cranks, multipoint inter-drive-assembly-coupling mechanism, a pair of pedals, a pair of drive enclosure brackets each of which secure a drive assembly to the frame via bracket support,

rear part which includes rear wheel assembly and

plurality of endless chains coupling the front and rear part.

[Claim 3] Rear wheel assembly, as claimed in [Claim 2], comprises a wheel at the rear part of bicycle with plurality of sprocket ratchet wheels coaxially mounted on each side of its hub.

[Claim 4] Each drive assembly, as claimed in [Claim 2], comprises

a special type of epicyclic gear which we refer as pivoted-slewing-bearing-epicyclic- gear, with plurality of chaincranks integrated to it.

[Claim 5] Pivoted-slewing-bearing-epicyclic-gear, as claimed in [Claim 4], comprises a

circular plate called as carrier plate having plurality of spur gears including planetary gears, a sun gear, satellite gears and far planet gears journalled to it and connected along its circumference to an internal toothed slewing bearing via U- shaped pegs, in arrangement such that

center of sun gear is at the center of the carrier plate,

carrier plate at its side containing sun gear is attached at its periphery to the outer ring of the said slewing bearing over-bridging gear ring with the help of U- shaped pegs such that slewing bearing is coaxial with Sun gear, each of planetary gears which are spur gears of equal radii is meshingly engaged with sun gear and gear ring of the slewing bearing,

each satellite gear is meshingly engaged with two adjacent planetary gears and a far planet gear,

each far planet gear is meshingly engaged with gear ring of the said slewing bearing and a satellite gear,

and a pivot plate, which is an eared circular plate with radius equal to the average of outer and inner radius of gear ring, is attached at its rim to the gear ring at its outer side and is coaxially journalled to the outer side of the carrier plate.

[Claim 6] Pivoted-slewing-bearing-epicyclic gear, described in [Claim 5], is constrained to follow the conditions that

number of planetary gears, satellite gears and far planet gears used are three radius of planetary gears being greater than the radius of sun gear, satellite gears and far planet gears;

radius of planetary gears are chosen such that the difference between the radius of planetary gears and internal gear ring of slewing bearing provides appropriate localized gear ratio and ease of pedaling;

satellite gears are of equal radii and far planet gears are of equal radii;

centers of three planetary gears forms an equilateral triangle with its circumcenter being center of sun gear;

centers of satellite gears and far planet gears falls on the perpendicular bisectors of the said triangle.

[Claim 7] Each of the planetary gears of pivoted-slewing-bearing-epicyclic gear, claimed in

[Claim 5], is attached to a coaxially parallel chain crank via a metal peg such that each chain crank is coplanar to one of the sprocket ratchet wheel mounted on rear wheel hub.

[Claim 8] Each chain crank claimed in [Claim 7] meshes with a coplanar sprocket ratchet wheel mounted on rear wheel hub via an endless chain claimed in [Claim 2]

[Claim 9] Multipoint inter-drive-assembly-coupling mechanism, mentioned in [Claim 2], consists of plurality of inter-drive-assembly coupling shafts each of which is a straight shaft coaxially connecting center of chain cranks on drive assembly on left side to the center of a coaxially parallel chain crank on the other drive assembly on the right side. [Claim 10] Drive bracket support, claimed in [Claim 2] is a vertical rectangular metal plate, coplanar with bicycle frame, is attached at its upper side to bottom end of down tube and seat tube and have ball bearings mounted on its plane each of which coaxially houses middle part of a inter-drive-assembly-coupling shaft, described in [Claim 9]

[Claim 11] Each of the pair of drive enclosure bracket, as claimed in [Claim 2], comprises

an enclosure which is in the form of cylinder, with its axis being perpendicular to the frame of the bicycle, attached at its inner side rim to drive bracket support, explained in [Claim 10], vertically sliced to have a rectangular opening facing rear part of the bicycle, with cylinder being of radius equal to the outer radius of slewing bearing and length approximately equal to distance between frame and a carrier plate, with opening big enough to provide space for the motion of front- rear-coupling shafts,

a circular annular plate, attached to outer side rim of the said enclosure, to which outer ring of drive assembly is fastened, and

a metal bar referred to as shaft stays connecting said rear part of circular annular plate to outer end of main bearing shaft of rear crank shaft explained in claim[3]

[Claim 12] A pedal, claimed in [Claim 2] is pivoted to the periphery of the pivot plate, claimed in [Claim 5], at its outer side.

[Claim 13] Carrier plates, claimed in [Claim 5], can be fixed to be stationary by directly

connecting it to the drive bracket support, described in [Claim 10], via rods.

[Claim 14] Rear wheel support mechanism claimed in [Claim 1], comprises rear bracket, rear bracket support and a pair of hub fasteners, one on right side of rear wheel and one on left side of rear wheel.

[Claim 15] Rear bracket comprises two V-shaped planar trusses parallel to the rear wheel with one truss located on right side of rear wheel and other located on left side of rear wheel.

[Claim 16] Rear bracket support, which connects upper ends of both the V-shaped planar trusses of rear bracket to the bicycle frame, comprises two forward slanting A-shaped trusses and a tube extending rearwardly from the rear end of top tube wherein

one A-shaped truss located on rear side of the seat tube is connected at its angled upper end to rear side of the said tube;

other truss located on front side of the seat tube is connected at its angled upper end to the top tube; bottom ends of two arms of front and rear A-shaped trusses are connected to upper front ends and upper rear ends, respectively of rear bracket;

[Claim 17] Each of V-shaped planar trusses, mentioned in [Claim 15], comprises two coplanar

V-shaped rods arranged one behind the other parallel to the rear wheel and a V- shaped peg located on corresponding side of the rear wheel wherein

each of V-shaped rods have acute angle bend facing the forward direction;

angled corners of V-shaped rods lies on the upper rear side of axle of the rear wheel;

angled corner of front side V-shaped rod is located vertically higher than that of rear side V-shaped rod;

each of V-shaped rods have one arm extending downwards with their bottom ends fixedly connected to the main bearing shaft of the rear crank shaft on the corresponding side of the rear wheel;

above mentioned downward extending rods may be suspension rod according to requirement thus forming bilateral rear wheel suspension;

upper ends of rear and front V-shaped trusses are connected to bottom ends of corresponding side arms of rear and front A-shaped trusses respectively;

V-shaped peg is attached at its angled corner to the angled corner of front side V- shaped rod at its rearward side and one arm as a rearward extension of lower arm of front side V-shaped rod with its upper end attached to upper arm of rear side V-shaped rod and other arm as a rearward extension of upper arm of front V-shaped rod with its lower end attached to lower arm of rear side V-shaped rod.

[Claim 18] In one possible variation of the drive mechanism claimed in [Claim l]-[Claim 13], wherein gear ring is only peripherally pivoted, pedals are directly pivoted on the outer side of the gear ring.

[Claim 19] In another possible variation of the drive mechanism claimed in [Claim l]-[Claim

13], wherein gear ring is only axially pivoted, carrier plate at its periphery is connected to drive bracket via U-shaped pegs over-bridging gear ring.

Description:
Title of Invention: Bicycle with Bilaterally Multichain Drive Mechanism and Forward Motion Promoting Rear Wheel Support:

Field of Invention

[01] The present disclosure relates generally to a bicycle with bilaterally multichain manual force transmission mechanism allowing concealment of chain from clothing and robust rear wheel support mechanism which can facilitate better bike kinematics.

Background of Invention

[02] Typically Bicycles with chain drive consists of a frame which facilitates installation of a chain crank on the front part of the bicycle at bottom. Frame comprises of a truss consisting of two triangles: the front triangle and the rear triangle. The front triangle consists of the head tube, top tube, down tube, and seat tube. The top tube connects the head tube to the seat tube at the top, and the down tube connects the head tube to the bottom bracket. Seat tube at its bottom is connected to the bottom bracket. The rear triangle consists of the seat tube and paired chain stays and seat stays. The chain stays run parallel to the chain, connecting the bottom bracket to the rear dropout, where the axle for the rear wheel is held. The seat stays connect the top of the seat tube (at or near the same point as the top tube) to the rear fork ends.

Sear stays are forward slanted due to which horizontal component of the portion of weight of rider that is supported by it pushes the rear wheel backward.

Technical Problem

[03] In the conventional chain driven bicycle, chains and chaincrank comes in contact with the rider's clothing.

[04] In conventional chain driven bicycle, the gear ratio is achieved by difference between radius of the front chain crank and rear sprocket. In order to increase higher achievable speed higher gear ratio is needed. Higher gear ratio would require front chain crank of bigger radius. This would cause the drive train to be closer to dirt on the ground, increased midspan movement and increase in the area of exposure of the drive train to rider's clothing.

[05] In the prior art it is prohibitively difficult to use multiple chains due to large size of the front chain crank. Multi chain transmission mechanism allows applying the driving force over a larger area to help in high speed or torque setups. [06] In the prior art frame of bicycle comprises of paired seat stays to secure the rear wheel. The seat stays are forward slanted due to which it impedes the forward movement of bicycle.

[07] Conventional bicycle have only one point coupling between the left side and the right side of the drive mechanism, that is, through the spindle housed in bottom bracket.

Summary of Invention

[08] One of the objectives is to provide bilateral sided drive mechanism to make maximum utilization of manual force on both sides of the bicycle. Drive mechanism consists of two force transmission mechanisms, one on each side of the bicycle.

[09] One of our objective is to provide multi axis drive mechanism which can facilitate to spread driving force applied by the rider to a larger area in order to be helpful in high speed or torque setups. In order to achieve this objective each drive assembly consists of multiple chain cranks. Chain cranks are located at different distances from the plane of the bicycle frame. Also each chain crank is mounted at different points on a plane parallel to the bicycle frame. Rear wheel has a flip-flop hub with multichain sprocket wheel mounted on each side of the hub. Each chain crank meshes, via a separate chain, with a separate sprocket mounted on the rear wheel. Thus spreading of area of application of manual force is achieved in three modes.

[10] One of our objective is to allow the ease of use provided by conventional bicycle that is drive mechanism allow the application of manual force via pedal rotation about fixed center.

[11] Objective of this invention is also to provide force transmission mechanism with

localized gear ratio and to conceal drive mechanism from the riders clothing.

[12] In order to achieve objectives [08]-[l 1] drive assembly is provided with a feature by

which it facilitates rider to rotate the chain cranks in the drive assembly by the rotation of pedals.

This feature is accomplished by employing pivoted-slewing-bearing-epicyclic gear (a special type of planetary gear box), mounted with chain cranks, and a pedal in each drive assembly as described below. Coaxially parallel planetary gears on drive assemblies on two sides of bicycle are connected by straight rods which in turn are mounted with coaxial chain cranks. These chain cranks on the drive assemblies rotates the sprockets mounted on the hub of the rear wheel via chain drives. Gear ratio is achieved by the difference in radius of outer ring gear and planetary gear of epicyclic gear. In normal configuration gear ratio is around 2.5. Drive mechanism including chains doesn't come in contact with clothing of the rider as they lie between the pair of carrier plates/pivot plates.

[13] Above mentioned drive assemblies have two variations. In one variation, gear ring is only peripherally pivoted and in another variation gear ring is only axially pivoted.

[14] One of our objective is to achieve the driving efficiency comparable to conventional chain driven bicycle.

This objective is achieved due to a feature which maximise the number of tooth of gear ring gear that is used to rotate the planetary gears.

This feature is accomplished by the appropriately journalling additional gears, apart from planetary and sun gears, to the carrier plate. These additional gears are classified in two categories, one is referred in this patent as satellite gears and the other as far planet gears. Far planetary gears, of smaller size as compared to planetary gears, are meshingly engaged with gear ring and their sole purpose is to provide additional rotatory force to planetary gears via satellite gears. Satellite gears are meshingly engaged with two adjacent planetary gears and a far planet gears. With this feature loss of manual force is further minimized. This feature also allows attaching chain cranks to the appropriate satellite gears so that they can function as tension gears.

[15] One of the various objectives is to provide robust wheel support system which, in

addition to secure the rear wheel, should facilitate better bike kinematics. We achieve this by replacing seat stay tube of conventional bicycle by robust wheel support mechanism consisting of rear bracket arranged in special orientation. Rear bracket is a pair of V- shaped planar trusses, which holds the rear wheel at two points of contact, is attached to the rear part of top tube via rear bracket support with the help of a pair of A-shaped trusses. Rear bracket has two dropouts at its bottom, one on each side of the wheel. With backward slanting, weight of the rider is utilized to push the wheel in forward direction. Contrarily with forward slanting, conventional seat stay tube pushes the wheel in backward direction due to the weight of the rider.

[16] One of the objective is to provide axial support to inter-drive assembly coupling shaft.

This objective is achieved via bracket support. Bracket support is rectangular plate positioned along the plane of the bicycle frame. Its upper side is connected to bottom ends of seat tube and down tube. Lower half is attached to bracket encasing drive assembly. The bracket support has ball bearing attached on its plane through which said shafts passes through. [17] One of our objective is to provide the scalability in the force transmission mechanism. This transmission mechanism allows to use 1, 2, 3, 4, 5, or 6 number of chains.

Brief Description of Drawings

[18] [Fig. 1] Side view of the preferred embodiment of a shaft driven bicycle integrated with robust rear wheel support mechanism, according to this invention.

[19] [Fig. 2] Back view of the bicycle according to this invention

[20] [Fig. 3] Perspective view of drive mechanism

[21] [Fig. 4] Top view of drive mechanism with bracket holder

[22] [Fig. 5] Front view Drive mechanism on one side

[23] [Fig. 6] Front view of Drive assembly

[24] [Fig. 7] Exploded back view of Drive assembly

[25] [Fig. 8] Drive enclosure bracket

[26] [Fig. 9] Rear wheel support mechanism

[27] [Fig. 10] Variation of the drive mechanism wherein gear ring is only peripherally pivoted

[28] [Fig. 11] Variation of the drive mechanism wherein gear ring is only axially pivoted

[29] [Fig. 12] Schematic diagram of drive assembly kinematic

[30] [Fig. 13] Schematic diagram of Six Chain arrangement

[31] [Fig. 14] Schematic diagram of Four Chain arrangement

[32] [Fig. 15] Schematic diagram of multipoint inter-drive assembly coupling

[33] [Fig. 16] Impact of weight of rider on rear wheel via rear wheel support mechanism

Description of Embodiments

[34] Referring to [FIG. 1], the preferred embodiment of a bicycle (1) according to this

invention is shown to include a frame consisting of head tube (HT), seat tube (ST), down tube (DT), top tube (TT), Drive Bracket Support (DBS), Drive Bracket (DB), shaft stays (SST), Drive mechanism (DM), Pedal (PDL), Rear wheel assembly (RWA), Rear Fork Support (RFS) and Rear Fork (RF) .

Frame

[35] As shown in [Fig. 1] this bicycle (1) has frame similar to conventional bicycle. It is a planar truss consisting of a front triangle and a rear parallelogram.

[36] The front triangle consists of the head tube (HT), seat tube (ST) down tube (DT) top tube (TT) and Bracket at the bottom to hold drive assembly. The top tube (TT) connects the head tube (HT) to the seat tube ST at the top. Top of down tube (DT) is attached to head tube (HT).

Bottom end of seat tube (ST) and down tube (DT) is attached to drive bracket support (DBS). Drive enclosure bracket (DB) securing drive assembly is connected to frame via drive bracket support (DBS).

[37] The rear parallelogram consists of the seat tube (ST) and paired chain stays (CST), rear fork support (RFS) and rear fork (RF).

[38] Rear fork support rod (RFS) is a L-shaped rod which being coplanar with the frame of bicycle, is in an orientation such that horizontal arm extends towards the rear end of the bicycle and vertical arm extends in the upward direction. Vertical arm of rear bracket support rod is connected at its top to the top of seat tube and rear end of top tube and horizontal arm at its rear end is connected to the crown of rear fork (RF).

Chain stays (CST), a metal bar, is connected at its rear end to an end of rear wheel assembly (RWA), running parallel to the shaft and are fixedly connected at its front end to the drive enclosure bracket (DB) at the other end.

Drive Mechanism

[39] As shown in [Fig. 3] drive mechanism (DM) consists of a pair of coupled drive

assemblies (DA) in the front, one on each side of the bicycle, rear wheel assembly (RWA) and plurality of endless chains (CITN) and pedals (PDL). Two drive assemblies are coupled via inter-drive-assembly-coupling shafts (CPL) shown in [Fig. 15] to improve their efficiency.

[40] Number of chains can be 1, 2, 3, 4, 5 or 6 according to user requirement. For illustration we have shown drive mechanism with one possible arrangement of four chains through [Fig. 5] and [Fig. 13] Drive mechanism having six chain arrangement is shown in schematic diagram in [Fig. 14]

Drive assembly

[41] Drive assembly (DA), as shown in [Fig. 3], comprises of a special type of epicyclic gear which we refer as pivoted-slewing-bearing-epicyclic-gear (SBE) and a pedal (PDL).

Pivoted-Slewing-bearing-epicyclic gear

[42] As shown in [Fig. 6] and [Fig. 7] pivoted-slewing-bearing-epicyclic-gear comprises of a circular plate called as carrier plate (CP) and plurality of planetary gears (Pl), (P2), (P3), a sun gear (Sl), plurality of satellite gears, (Satl), (Sat2), (Sat3) plurality of far planet gears, (FP1) (FP2) (FP3) internal-toothed slewing bearing (ISB) and U-shaped pegs

(UPG), straight metal pegs (PPG) and an eared circular plate (PIV).

Internal toothed slewing bearing (ISB) consist of an internal gear ring (SGR) with internal toothing coaxially mounted on external ring (SOR) and an integrated raceway system rolling elements - balls or cylindrical rollers - that are separated by spacers. In slewing bearing, internal gear ring (SGR) can rotate with outer ring (SOR) fixed along a fixed axis, whilst guaranteeing the axial and radial link between the two parts.

Outer ring (SOR) is preferably flanged.

Three planetary spur gear (Pl), (P2), (P3), sun gear (Sl), three satellite gears (Satl), (Sat2), (Sat3) and three far planet gears (FP1), (FP2), (FP3) are journalled to the carrier plate (CP) in an arrangement as explained below.

Sun gear (Sl) which is a spur gear is journaled to the center of the carrier plate (CP). Planetary gears (Px) are spur gears of equal radii, and journalled to carrier plate (CP) such that each of them is me shingly engaged with sun gear (Sl) and gear ring (SGR) of the slewing bearing. Centers of planetary gears form an equilateral triangle.

Each satellite gear (Satx) which is a spur gear with radius smaller than that of planetary gears is journalled to the carrier plate such that it is meshingly engaged with two adjacent planetary gears and a far planet gear.

Centers of satellite gear form an equilateral triangle.

Each far planet gear (FP1), (FP2), (FP3) which is a spur gear with radius smaller than that of planetary gears is journalled to the carrier plate such that it is meshingly engaged with gear ring of the said slewing bearing and a satellite gear.

Carrier plate (CP) at its inner side, containing sun gear (Sl), is attached at its periphery to the outer ring (SOR) of the said slewing bearing over-bridging gear ring (SGR) with the help of El-shaped pegs (EIPG) such that slewing bearing is coaxial with Sun gear (Sl).

As shown in [Fig. 7], an eared circular plate (PIV) called as pivot plate, coaxially journalled to outer side of the carrier plate via ball bearing (PIVB), is attached at its rim to the outer side of gear ring (SGR).

Drive assembly input and output

[43] As shown in [Fig. 5], planetary gears are attached to coaxially parallel chain cranks (CR) via metal pegs. Chain cranks meshing with same chain should be at same height from their respective planetary gear. Chain cranks meshing with different chains should be at different heights from their respective planetary gear. Pedal on the left side drive assembly is in diametrically opposite position to that on right side drive assembly.

[44] As shown in [Fig. 3] a pedal (PDL) A pedal is attached at the periphery on the outer side of the pivot plate (PIV). Internal gear ring (SGR) act as input point and chain cranks (CR) connected to planetary gears act as output points of front drive assembly.

Multipoint inter-drive-assembly coupling

[45] As shown [Fig. 6] and [Fig. 15], pair of coaxially parallel drive assemblies (DA) are coupled via straight shafts (CPL). Chain cranks (CR) of left side drive assembly at its center is connected to the center coaxially parallel chain cranks (CR) on the right side drive assembly via straight shafts (CPL). Though not necessary for the functioning of drive mechanism, coupling between the drive assemblies does significantly improves the driving capability and efficiency.

Rear wheel assembly

[46] As shown in [Fig. 2], rear wheel assembly (RWA) comprises of a wheel (RW) with axle (RAX), plurality of sprocket ratchet wheel (SP) coaxially mounted on the hub (RHB) on both sides of the rear wheel. Each sprocket ratchet wheel is coplanar one of the chain cranks in drive assemblies on the front part of the bicycle.

Force Transmission Coupling

[47] As shown in [Fig. 5], each chain crank (CR) in the drive assemblies (DA) meshes with a coplanar sprocket rocket ratchet wheel (SP) on the rear wheel hub via a chain drive (CHN).

Rear Wheel Support Mechanism

[48] As shown in [Fig. 1], [Fig. 2] and [Fig. 9] robust rear wheel support mechanism (RWSM) comprises rear bracket (RB) and rear bracket support (RBS). It secures the rear wheel in robust manner and additionally facilitates better bike kinematics.

[49] As shown in [Fig. 1], [Fig. 2] and [Fig. 9], rear bracket (RB) comprises two V-shaped planar trusses parallel to the rear wheel with one truss (RRB) located on right side of rear wheel and other (LRB) located on left side of rear wheel. Rear bracket support (RBS) connects upper ends of both the trusses of rear bracket to the bicycle frame.

[50] As shown in [Fig. 1], [Fig. 2] and [Fig. 9], rear bracket support (RBS) comprises two forward slanting A-shaped trusses (RBS1) and (RBS3) and a tube (RBS2) extending rearwardly from the rear end of top tube (TT). One A-shaped truss (RBS1) located on rear side of the seat tube is connected at its angled upper end to rear side of the tube (RBS2) and other truss (RBS3) located on front side of the seat tube is connected at its angled upper end to the top tube (TT).

Bottom ends of two arms of A-shaped truss (RBS3) and (RBS1) are connected to upper front ends and upper rear ends, respectively of V-shaped trusses (RRB) and (LRB). [51] As shown in [Fig. 1], [Fig. 2] and [Fig. 9], V-shaped planar truss (RRB) comprises two coplanar V-shaped rods (RRB1) and (RRB2) and a V-shaped peg (RRB3). V-shaped planar truss (RRB) is configured such that each of V-shaped rods (RRB1) and (RRB2) have acute angle bend facing the forward direction; V-shaped rod (RRB1) lies on the rear side of V-shaped rod (RRB2); angled corners of V-shaped rods (RRB1) and (RRB2) lies on the upper rear side of axle of the rear wheel; angled corner of V-shaped rod (RRB1) is located vertically higher than that of V-shaped rod (RRB2); each of V-shaped rods (RRB1) and (RRB2) have one arm extending downwards with their bottom ends fixedly connected to the axle (RAX) on the right side of the rear wheel (RW); upper ends of V- shaped trusses (RRB1) and (RRB2) are connected to bottom ends of right arms of A- shaped trusses trusses (RBS1) and (RBS3) respectively; V-shaped peg (RRB3) is attached at its angled corner to the angled corner of front side V-shaped rod (RRB2) at its rearward side and one arm as a rearward extension of lower arm of V-shaped rod (RRB2) with its upper end attached to upper arm of rear V-shaped rod (RRB1) and other arm as a rearward extension of upper arm of front V-shaped rod (RRB2) with its lower end attached to lower arm of rear V-shaped rod (RRB1).

[52] As shown in [Fig. 1], [Fig. 2] and [Fig. 9], V-shaped planar truss (LRB) comprises two coplanar V-shaped rods (LRB1) and (LRB2) and a V-shaped peg (LRB3). V-shaped planar truss (LRB) is configured such that each of V-shaped rods (LRB1) and (LRB2) have acute angle bend facing the forward direction; V-shaped rod (LRB1) lies on the rear side of V-shaped rod (LRB2); angled corners of V-shaped rods (LRB1) and (LRB2) lies on the upper rear side of axle of the rear wheel; angled corners of V-shaped rods (LRB1) and (LRB2) lies on the upper rear side of axle of the rear wheel; each of V-shaped rods (LRB1) and (LRB2) have one arm extending downwards with their bottom ends fixedly connected to the axle (RAX) on the left side of the rear wheel (RW); upper ends of V- shaped trusses (LRB1) and (LRB2) are connected to bottom ends of left arms of A- shaped trusses (RBS1) and (RBS3) respectively; V-shaped peg (RRB3) is attached at its angled corner to the angled corner of front side V-shaped rod (RRB2) at its rearward side and one arm as a rearward extension of lower arm of V-shaped rod (RRB2) with its upper end attached to upper arm of rear V-shaped rod (RRB1) and other arm as a rearward extension of upper arm of front V-shaped rod (RRB2) with its lower end attached to lower arm of rear V-shaped rod (RRB1). [53] With this mechanism, weight of the rider is utilized to push the wheel in forward direction. Conventional seat stays push the wheel in backward direction due to the weight of the rider.

Drive Enclosure Bracket

[54] As shown in [Fig. 1] two drive assemblies (DA), are secured to the frame at its bottom of front triangle by a pair of drive enclosure brackets (DB) in a position so that they are coaxially parallel to each other and are at equal distance from the plane of the bicycle. Keeping the outer ring (SOR) fixed is necessary for the functioning of drive mechanism.

[55] As shown in [Fig. 8] drive enclosure bracket (DB), comprises of an enclosure (BCL) which is in the form of cylinder vertically sliced to have a rectangular opening at a required distance from the center, with cylinder being of radius equal to the outer radius of slewing bearing and length approximately equal to half the length of inter-drive coupling shafts. Opening is to provide space for the motion of chains (CHN). Enclosure (BCL) is attached at its rim on one side to the bracket support such that rectangular opening is facing the rear side of the bicycle. Rim on the other side of the enclosure is attached coaxially to a circular annular plate (BCA).

Cylindrical enclosure (BCL) of the two drive assemblies are coaxially parallel with each other. Outer ring (SOR) of drive assemly (DA) is fastened to (BCA).

Drive Braket support (DBS) is a rectangular plate attached to the bottom ends of down tube (DT) and seat tube (ST). It has ball bearings (DBB), shown in [Fig. 8] and [Fig. 15], on its plane on which inter-drive assemblies coupling rods (CPL) are axially mounted. Note that carrier plates can be fixed to be stationary by directly attaching it to the frame in variety of ways. For example, it can be fixedly connected to the Drive Bracket Support (DBS).

Chain stays (CST) at one end connected to rear axle running parallel to the chain and are welded to circular annular plate of the bracket at the other end. Chain stay (CST) has two vertical extensions to hold optional tension gears.

Variations of Drive Mechanism

[56] In one possible variation of the drive mechanism, wherein there is no pivot plate and gear ring is only peripherally pivoted, pedals are directly pivoted on the outer side of the gear ring (SGR) as shown in [Fig. 10]

[57] In one possible variation of the drive mechanism, wherein gear ring is not part of slewing bearing and is only axially pivoted at its center to carrier plate (CP) and carrier plate at its periphery is connected to drive bracket (DB) via U-shaped pegs (UPG) as shown in [Fig. 11] ยท

Drive operation

[58] Internal gear ring functions as the input from manual force to the drive assemblies with the help of pedals. One or more planetary gears meshes with a coplanar sprocket wheel attached to the axle of the rear wheel via chain.

Impact of Rear Wheel Support Mechanism

[59] Let W1 be the force, due to weight W of the rider, acting along the plane of lower arm of rear bracket (RB). As shown in the [Fig. 16] horizontal component of this force W 1 H is in the direction of the motion of the bicycle.