WO2016147024A1

WO2016147024A1 - Front wheel-drive recumbent bicycle with fully self-contained folding mechanism

Info

Publication number: WO2016147024A1
Application number: PCT/IB2015/051870
Authority: WO
Inventors: Mohamed Rizwan MUZZAMMIL
Original assignee: Muzzammil Mohamed Rizwan
Priority date: 2015-03-14
Filing date: 2015-03-14
Publication date: 2016-09-22

Abstract

A front wheel-drive recumbent bicycle with fully self-contained folding mechanism comprising a bicycle frame, a drive-train, front and rear wheels, and a rear rack (56) comprising four roller wheels (58). Folding hinges are provided on a steering stem (26), a top tube (34), at a interface between the seat tube (40) and rear-frame portion, and at a interface between a seat pan (44) and a seat back (42) in order that the bicycle can be folded into a compact structure in four steps. The folded bicycle rests on a surface by way of the four roller wheels (58) which facilitates ease of handling, ease of storage and multi modal commuting.

Description

Title of Invention : FRONT WH EEL-DRIVE RECU M BENT BICYCLE WITH FU LLY SELF- CONTAI N ED FOLDI NG M ECHAN ISM

Background of the invention - Field of Invention

[1] The present invention relates generally to bicycles.

Background of the Invention

[2] Recumbent bicycles or recumbents which place cyclists in the reclined orientation have been available for years. Some advantages of recumbents are as follows: a. The reclined orientation lowers wind resistance and hence improves cyclist efficiency. b. The reclined orientation is similar to the driver position of motor vehicles and thus

facilitates better frontal visibility and hence safety.

c. The larger seat of recumbents is generally more comfortable than the seats found on conventional upright bicycles. This encourages cycling and the benefits thereof.

d. The distinct and unfamiliar shape of recumbents catches attention more easily in traffic in comparison with conventional upright bicycles. This encourages motorist caution and hence safety.

[3] Despite these advantages recumbents have failed to capture a significant market share. One possible reason for this is the larger size and bulk that is characteristic of the bicycle type. These characteristics may be perceived as inconvenient for the purposes of storage and transport.

[4] The problem of storage may be addressed by utilizing a folding recumbent bicycle. The folding recumbents presently available in the market are unable to fold to a compact size without detachment of some component. The detachment of a component can cause the overall folded system to become unwieldy and inconvenient to manage. These types of folds are therefore more suitable if done infrequently in situations, for example, when the bicycle is folded for long term storage or disassembled for travel. An everyday commuting cyclist, preferring a bicycle that can be quickly folded and unfolded for use with multimodal transportation or for storage at the workplace or at home may find these recumbents inconvenient for use. Background of the Invention - Objects and Advantages

[5] The presented recumbent bicycle solves the aforesaid problems through the advantages listed below: a. The bicycle folds quickly and easily requiring no detachment of any component during or after the process. This results in a more easily accomplished folding process and a more manageable folded bicycle.

b. The bicycle folds into a compact structure occupying a spatial volume comparable to conventional upright folding bicycles available in the market. The compact nature of the folded bicycle is practical for the purposes of storage at the workplace, at home, in modes of public and private transportation etc.

c. The folded bicycle rests on roller or trolley wheels which can be used to easily move and maneuver it along surfaces. This feature is useful for improving the ease at which the bicycle is handled whilst it is in its folded form.

[6] The aforesaid objects and advantages are not exclusive. Still further objects and advantages will become apparent from a consideration of the ensuing descriptions and drawings.

Summary

[7] In accordance with the presented invention a front wheel-drive folding recumbent bicycle

comprising a bicycle frame, front and rear wheels, a steering stem folding hinge, a top tube folding hinge, a seat tube folding hinge, a seat folding hinge, a device to secure a rear-frame portion of the bicycle frame to a center-frame portion of the bicycle frame (for when the bicycle is in its unfolded form), a device to secure a front-frame portion of the bicycle frame to the rear- frame portion of the bicycle frame (for when the bicycle is in its folded form), and a rear rack comprising roller wheels upon which the folded bicycle rests on a surface, wherein the bicycle is foldable to a compact size without necessitating removal of any component.

Drawings - Figures

[8] Fig 1 shows a general isometric view of a recumbent bicycle in an unfolded state.

[9] Fig 2 shows a general isometric view of the recumbent bicycle in a folded state.

[10]Fig 3 shows a detailed view of a top tube hinge in a closed position (port side view). Brake and gear cables are omitted for clarity.

[11] Fig 4 shows a detailed view of the top tube hinge in a closed position (starboard side view). [12] Fig 5 shows a detailed view of the top tube hinge in an open position. Brake and gear cables are omitted for clarity.

[13] Fig 6 shows a detailed view of a steering stem hinge in a closed position (port side view).

[14]Fig 7 shows a detailed view of the steering stem hinge in an open position.

[15] Fig 8 shows a detailed view of a seat tube hinge with a rear fold securing device in a closed

position.

[16] Fig 9 shows a detailed view of the seat tube hinge with the rear fold securing device in an open position.

[17] Fig 10 shows the recumbent bicycle in a folded state viewed from the rear starboard side.

Emphasis is given to a front fold securing device and the rear fold securing device. A steering handlebar, a drive-train, and a brake assembly are omitted for clarity.

[18] Fig 11 shows a seat back in a folded position (port side view). A seat post is shown as retracted into a seat post tube.

[19] Fig 12 shows a detailed view of a seat back quick release clamp.

[20]Fig 13 shows an illustration of the first step in the folding process.

[21] Fig 14 shows an illustration of the second step in the folding process.

[22] Fig 15 shows an illustration of the third step in the folding process.

[23] Fig 16 shows an illustration of the fourth step in the folding process.

Drawings - Reference Numerals

In the reference numerals, closely related items have the same number but different alphabetic suffixes.

[24]2 drive-train

[25]4 front wheel

[26]4a front wheel dropout [27]6 rear wheel

[28]6a rear wheel dropout

[29]8 front-frame portion

[30]10 center-frame portion

[31]12 rear-frame portion

[32]14 telescopic steering boom

[33]15 steering boom clamp

[34]16 twin front chain stays

[35]18 bottom bracket shell

[36]20 twin fork blades

[37]22 front suspension unit

[38]24 front fold securing device

[39]26 steering stem

[40]28 steering stem folding hinge

[41]30 head tube

[42]32 steering handlebars

[43]34 top tube

[44]36 top tube folding hinge

[45]38 down tube

[46]40 seat tube

[47]41 seat tube hinge [48]42 seat back

[49]43 seat back quick release clamp

[50]44 seat pan

[51]45 seat pan clamp

[52]46 seat post

[53]47 seat folding hinge

[54]48 seat post clamp

[55]50 twin rear stays

[56]52 twin seat stays

[57]54 twin support members

[58]55 rear suspension unit

[59]56 rear rack

[60]58 roller wheels

[61]60 rear fold securing device

[62]62 front and rear brake levers and gear shifter

[63]64 cables for front brake, rear brake and gear assembly

[64]66 entry opening for top tube hollow space Detailed Description - General Outline of Components

[65]A preferred embodiment of a front wheel-drive recumbent bicycle with a fully self-contained folding mechanism is shown in its unfolded state in Fig 1.

[66]The bicycle comprises a drive-train 2 (i.e. the mechanism used to power the bicycle), a front wheel 4, a rear wheel 6 and a bicycle frame. The bicycle frame comprises a front-frame portion 8, a center-frame portion 10, and a rear-frame portion 12.

[67]The front wheel and rear wheel are both rotatably mounted to pairs of front wheel dropouts 4a and rear wheel dropouts 6a respectively.

[68]The front-frame portion 8 comprises a telescopic steering boom 14, a steering boom clamp 15, twin front chain stays 16, a bottom bracket shell 18, twin fork blades 20, a front brake assembly, a front mud-guard, a front suspension 22, a front fold securing device 24, a steering stem 26, a steering stem folding hinge 28, an internal steering tube, and steering handlebars 32.

[69]The center-frame portion 10 comprises a top tube 34, a top tube folding hinge 36, a head tube 30, a down tube 38, a seat tube 40, a seat tube hinge 41, a seat back 42, a seat back quick release clamp 43 (not visible in Fig), a seat pan 44, a seat pan clamp 45, a seat post 46, a seat folding hinge 47, and a seat post clamp 48.

[70]The rear-frame portion 12 comprises twin rear wheel stays 50, twin seat stays 52, a rear brake assembly, a rear mud guard, two supporting members or strut members 54, a rear suspension unit 55, a rear fold securing device 60, and a rear rack 56 upon which four roller wheels or trolley wheels 58 are rotatably mounted.

[71]The center-frame portion 10 spans between the front-frame portion 8 and rear-frame portion 12.

The front-frame portion is pivotally coupled to the center-frame portion by way of the internal steering tube threaded through the head tube 30. The rear-frame portion is pivotally connected to the center-frame portion by way of the seat tube hinge 41, and it is secured in the unfolded bicycle position by way of the rear fold securing device 60.

Detailed Description - Arrangement of components belonging to front-frame portion

[72]The twin front chain stays 16 and twin fork blades 20 comprise upper ends which are joined and lower ends which are separate. The front brake assembly and the front mud guard are connected to the upper end of the twin fork blades. The internal steering tube comprises an upper end and a lower end. The front wheel dropouts 4a, upon which the front wheel 4 is rotatably mounted, are a feature of the twin fork blade lower ends.

[73]The upper end of the twin fork blades 20 is connected to the front suspension unit 22. The front suspension unit is connected to the lower end of the internal steering tube. The internal steering tube is threaded through the head tube 30.

[74]The front suspension unit 22 is provided in order to mitigate sudden impact forces caused by irregular cycling surfaces. If it is envisioned that the bicycle is to be used on smooth cycling surfaces then it is desirable to omit the front suspension unit as this will save weight and improve efficiency. For this situation the upper end of the twin fork blades 20 can be directly connected to the lower end of the internal steering tube.

[75]The lower ends of the front twin chain stays 16 and lower ends of the twin fork blades 20 are connected together. The front fold securing device 24 is connected to the lower end of the port side fork blade.

[76]The upper end of the twin chain stays 16 is pivotally connected to the bottom bracket shell 18.

The bottom bracket shell is rigidly connected to the telescopic steering boom 14.

[77]The steering stem 26 comprises an upper end and a lower end. The lower end of the steering stem is attached to the upper end of the internal steering tube.

[78]The telescoping steering boom 14 pivotally connects to the steering stem 26. This connection is made at any point between the steering stem folding hinge 8 and the head tube 30.

[79]The telescopic steering boom 14 comprises two structural members, an internal tube and an external tube. The internal tube slides within the external tube thereby facilitating the telescopic feature. The two tubes are fixed in relation to each other by way of the steering boom clamp 15. The telescopic steering boom is used in order to adjust the fit of the bicycle in order to accommodate a variety of cyclist leg lengths.

[80]The upper end of the steering stem 26 connects to the center of the steering handlebars 32. The steering handlebars comprise handlebar grips, a front brake lever, a rear brake lever, a gear shifter 62 and associated brake and gear specific cabling 64.

[81]The drive-train 2 is coupled to the front wheel 4 in such a manner as to allow the front wheel to be powered by cyclist enabled pedal action. The drive-train shown in Fig 1 comprises a single chain-ring and an internal hub gearing system. This system is provided due to its low

maintenance and straightforward arrangement that is suitable for commuting usage. However the arrangement of the front-frame portion 8 components is compatible with most standard drive-trains available in the market.

[82]Most recumbents available in the market comprise a drive-train 2 coupled to the rear wheel 6.

This configuration typically results in a very long drive-train and thus, due to increased mechanical complexity, results in lower energy efficiency. The front wheel-drive configuration of the presented bicycle has a short compact drive-train similar to what is present in conventional upright style bicycles. The energy efficiency of this drive-train is thus comparable to conventional upright style bicycles.

[83]The cabling specific to the gear shifter and front brakes are extended downward from the

steering handlebars 32 and connect to the internal gear hub and front brake assembly respectively.

Detailed Description - Arrangement of components belonging to center-frame portion

[84]The top tube 34 comprises a proximal end, a distal end and a top tube folding hinge 36. The head tube 30 is welded to the proximal end of the top tube. The head tube is positioned at an angle approximately perpendicular in relation to the top tube. The top tube comprises an internal hollow space for cable management. The hollow space is accessed by way of an entry opening 66 (see Fig 3) and an exit opening provided at the proximal and distal ends of the top tube respectively. The rear brake cable 64 is threaded through the top tube hollow space.

[85]The down tube 38 comprises an upper end and a lower end. The upper end of the down tube is welded to the top tube 34 at a position between the approximate midpoint of the top tube and top tube distal end. The clearance between this welded point and the head tube 30 is such that, after the bicycle is folded, there is sufficient space for the rear wheel 6 to be relocated to beneath the top tube whilst avoiding interference with the down tube.

[86]The seat tube 40 comprises an upper end, a lower end and a seat post clamp 48. The lower end of the down tube 38 is welded to the lower end of the seat tube 40 and the distal end of the top tube 34 is welded to the upper end of the seat tube. Thus a triangular shape is formed between part of the top tube, seat tube and down tube. The shape formed provides a stable structure for the purpose of withstanding the weight of a seated cyclist.

[87]The cyclist rests in a reclined position on the seat pan 44 and the seat back 42. The seat pan is attached, by way of the seat pan clamp 45, to the top tube 34 at any plurality of lengths between the top tube folding hinge 36 and top tube distal end. [88]The seat pan 44 comprises a distal end. The seat back 42 comprises an upper end and a lower end. The seat pan distal end connects to the seat back lower end by way of a seat folding hinge 47 (see Fig 10). The seat back is attached by way of the seat back quick release clamp 43 to the upper end of the seat post 46. The seat post is partially inserted into the seat tube 40 and clamped therein into position by way of the seat post clamp 48.

[89]The position of the seat pan 44 in the approximate horizontal plane is adjustable by way of the seat pan 44 clamped position on the top tube 34. The seat pan position adjustment also facilitates the fitting of the recumbent to a variety of cyclist leg lengths.

[90]The reclined angle of the seat back 42 is changeable by way of utilizing the seat post clamp 48 and seat back quick release clamp 43 to adjust the seat post 46 apparent length. Lowering the reclination angle of the seat back allows the cyclist to recline further. This reduces wind resistance and improves the overall aerodynamic characteristics and speed of the cyclist and recumbent. However a lowered reclination angle can also compromise cyclist forward visibility and maneuverability. For this reason a higher reclination angle of the seat back may be preferred for situations when the cyclist encounters heavy vehicular or pedestrian traffic.

Detailed Description - Arrangement of components belonging to rear-frame portion

[91]The twin rear stays 50 have proximal ends and distal ends. The twin seat stays 52 and two

supporting members 54 have upper ends which are joined and lower ends which are separate. The rear brake assembly and the rear mud guard are connected to the twin seat stays. The rear brake cable 64 is extended from the steering handlebars 32 and, after being threaded through the top tube hollow space, is connected to the rear brake assembly.

[92]The proximal ends of the twin rear stays 50 connect to the lower ends of the supporting

members 54. The joined upper end of the supporting members connects to the joined upper ends of the twin seat stays 52. The lower ends of the twin seat stays connect to the distal ends of the twin rear stays. In this manner the twin rear stays, twin seat stays and two supporting members form a twin triangular truss structure. Additional cross bracing members are provided to the triangular truss structure for greater stability. This structure supports the rear wheel 6. The rear wheel dropouts 6a are a feature of the twin rear stay distal ends.

[93]The rear rack 56 structure connects to the upper and lower ends of the twin seat stays 52 in a manner so as to serve as a luggage bearing rack for when the bicycle is in its unfolded form. The four roller wheels 58 are rotatably mounted at the corners of the flat upper portion of the rear rack. The four roller wheels are mounted such that the direction of rotation is the same as the rear wheel 6. [94]The proximal ends of the twin rear stays 50 are pivotally connected by way of the seat tube hinge 41 to the lower end of the seat tube 40. The joined upper end of the twin seat stays 52 is connected to the rear suspension unit 55. The rear suspension unit abuts the seat post clamp 48 (see Figs 8 and 9). The rear suspension unit, and by association the rear-frame portion 12, is held in this position by way of the rear fold securing device 60.

[95]The rear suspension unit 55 is provided in order to mitigate sudden impact forces caused by irregular cycling surfaces. If it is envisioned that the bicycle is to be used on smooth cycling surfaces then it is desirable to omit the rear suspension unit as this will save weight and improve efficiency. For this situation the proximal end of the twin seat stays 52 will abut the seat post clamp 48.

Detailed Description - Method of folding the recumbent bicycle

[96]The folded recumbent bicycle is shown in Fig 2. The method of folding the bicycle is a four step process which is illustrated in Figs 13, 14, 15 and 16.

[97]ln order to facilitate the fold in Fig 13 the rear fold securing device 60 is opened thus releasing the rear-frame portion 12 from its unfolded position. The open and closed positions of the rear fold securing device 60 are shown in Figs 8 and 9 respectively. The rear-frame portion 12 pivots about the seat tube hinge 41 into its folded position. The folded position is such that the rear- frame portion and rear wheel 6 lie substantially beneath the top tube 34. The position of the rear rack 56 is such that the bicycle rests on a surface by way of the roller wheels 58. The roller wheels facilitate the moving and maneuvering of the bicycle whilst it is in its folded form as illustrated in Fig 2.

[98]The fold shown in Fig 14 is facilitated by opening the top tube hinge 36 (see Figs 3, 4, and 5 for detailed views of the top tube hinge) and thereafter displacing the top tube 34 proximal end and front-frame portion 8 in a manner such that the front-frame portion lies substantially alongside the center-frame portion 10. The front fold securing device 24 is thereafter latched on to the starboard side rear stay 50 as illustrated in Fig 10.

[99]The fold shown in Fig 15 is facilitated by opening the steering stem hinge 28 (see Figs 6 and 7 for detailed views of the steering stem hinge) and thereafter displacing the upper end of the steering stem 26 downwards in a manner such that the steering stem and associated steering handlebars 32 thereof lie substantially alongside the center-frame portion 10.

[100] The steps illustrated in Figs 13, 14 and 15 are easy and quick to implement and sufficient for the purposes of folding for temporary storage or public transport use. For greater compactness the fold shown in Fig 16 is provided. [101] The fold shown in Fig 16 is facilitated by opening the seat back quick release clamp 43

(see Fig 12) and the seat post clamp 48. The seat post is thereafter lowered into the seat tube 40. The seat back 42, being no longer connected to the seat post, is rotated forward about the seat folding hinge 47 into its folded position as illustrated in Fig 11.

Detailed Description - Additional Descriptions

[102] The provided front and rear brake assemblies are of a rim brake type which is widely utilized in the market. Other brake types that are available are drum brakes and disk brakes. The bicycle frame is also able to accommodate these brake types.

[103] Front fairings are useful in order to improve wind resistance and provide additional protection for the cyclist. The bicycle provided in this patent comprises no front fairing. It is envisioned that market available front fairings can be easily installed on to the front-frame portion 8. It is further envisioned that the overall folding process may not be compromised through careful choice of front fairing and appropriate adjustment of its position in relation to the front frame portion.

Concluding Remarks

[104] Although the descriptions above contain many specificities, these should not be

construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.

Claims

[Claim 1] A front wheel-drive recumbent bicycle, comprising: a. a drive-train, a front wheel, a rear wheel, and a bicycle frame, and b. said bicycle frame comprising a front-frame portion, a rear frame portion and a center-frame portion, wherein said center-frame portion spans between said front- frame portion and said rear frame portion, and c. said rear frame portion is pivotally hinged to said center-frame portion by way of a seat tube folding hinge and secured in position therein by way of a first means for securing said rear frame portion, and said front-frame portion is pivotally coupled to said center frame portion by way of a steering tube passing through a head tube, and d. said front-frame portion comprising a steering stem, a second means for securing said front-frame portion, and a front truss structure upon which said front wheel and said drive-train are mounted, wherein said drive-train is coupled to said front wheel in a manner as to allow energy produced by way of a cyclist enabled pedal action to be transmitted to said front wheel thereby resulting in said front wheel being driven rotationally, and e. said center-frame portion comprising a center truss structure and a seat, and said center truss structure comprising a top tube, wherein said top tube comprising a proximal end, a distal end and a top tube folding hinge, and f. said seat connecting to said top tube at a position nearer to said distal end of top tube, and said top tube folding hinge positioned along a length of said top tube between said proximal end of top tube and said connected position of seat, wherein said seat and said center truss structure are capable of supporting a weight of said cyclist, and g. said rear-frame portion comprising a rear rack, and a rear truss structure upon which said rear wheel and said rear rack are mounted, and h. said steering stem comprising an upper end, a lower end and a steering stem

folding hinge, wherein said upper end of steering stem is connected to a third means for steering said bicycle, and said steering stem folding hinge is positioned at a point closer to said lower end of steering stem, whereby said front and rear wheels rest on a surface, wherein said bicycle is capable of being driven by cyclist enabled pedal action, and

i. said steering stem is capable of folding by way of said steering stem folding hinge in a manner such that said upper end of steering stem thereof lies substantially alongside said front-frame portion, and j. said front-frame portion is capable of folding by way of said top tube folding hinge in a manner such that said front-frame portion lies substantially alongside said center-frame portion and is secured therein by way of said second means, and k. said rear-frame portion is capable of folding by way of said seat tube folding hinge in a manner such that said rear-frame portion lies substantially beneath said top tube, whereby said bicycle is capable of folding to a compact size, wherein said folded bicycle rests on said surface by way of said rear rack.

[Claim 2] A front wheel-drive bicycle as claimed in 1 wherein, a. said seat comprising a fifth means for folding said seat, and an underside further comprising proximal and distal ends, and b. said rear truss structure comprising a seat tube and a seat post, wherein said seat post comprising an upper end connecting to a sixth means for attaching and detaching said seat post to said distal end of seat underside, and c. said seat post is capable of being lowered or raised within said seat tube in a

telescopic fashion, and d. said seat post is fixed in place by a seventh means for clamping said seat post

within said seat tube, and e. said proximal end of seat underside is connected to said top tube at a point nearer to said distal end of top tube by an eighth means for clamping said seat to top tube, whereby a reclined angle of said seat is changeable by way of adjusting said seat post position by said seventh means and adjusting said clamped position of seat on top tube by said eighth means, whereby said distal end of seat underside is capable of detaching from said seat post by way of said sixth means and foldable by way of said fifth means to a compact size.

[Claim 3] A front wheel-drive recumbent bicycle as claimed in 1 wherein, a. said rear rack comprising a fourth means to move and maneuver said folded bicycle on said surface,

whereby said bicycle is capable of folding to a compact size, wherein said folded bicycle rests on said surface by way of said fourth means.

[Claim 4] A front wheel-drive recumbent bicycle as claimed in 2 wherein, a. said rear rack comprising a fourth means to move and maneuver said folded bicycle on said surface,