*EP A1* EP A1 (19) (11) EP A1 (12) EUROPEAN PATENT APPLICATION. (43) Date of publication: Bulletin 2001/43

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1 (19) Europäisches Patentamt European Patent Office Office européen des brevets *EP A1* (11) EP A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: Bulletin 2001/43 (51) Int Cl. 7 : B62M 17/00 (21) Application number: (22) Date of filing: (84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (71) Applicant: Liu, Jen-Chih Kaohsiung City (TW) (72) Inventor: Liu, Jen-Chih Kaohsiung City (TW) (74) Representative: Pendered, Timothy George et al R.G.C. Jenkins & Co. 26 Caxton Street London SW1H 0RJ (GB) (54) Chainless transmit device for bikes (57) A chainless transmit device for a bike includes a front bevel gear unit and a rear bevel gear unit and a first flexible or hard transmit means and a second flexible or hard transmit means coupled with each other. The front bevel gear unit consists of a large bevel gear and a small bevel gear engaging with each other. The front large bevel gear is fixed on the shaft of a pedal of a conventional chain transmit bike, and the front small bevel gear is connected to the first flexible or hard transmit means connected with the second flexible or hard transmit means connected to the rear small bevel gear engaging the rear large bevel gear fixed on the shaft of the rear wheel of a conventional chain transmit bike. Thus, the chainless transmit device can replace the chain transmit device of common conventional chain transmit bikes without changing or modifying the bike body. EP A1 Printed by Jouve, PARIS (FR)

2 1 EP A1 2 Description BACKGROUND OF THE INVENTION [0001] This invention relates to a chainless transmit device for bikes, particularly to one adaptable to common chain transmit bikes without remodeling its body. [0002] Common conventional bikes are generally provided with a chain extending around a chain gear fixed with a pedal shaft, and a chain gear fixed with a shaft of a rear wheel, but have various disadvantages such as the end of a pair of trousers or a skirt being pulled in by the chain in running a bike, the chain falling off the chain wheel, etc. So many patents regarding to a chainless transmit device for bikes have been disclosed in U. S. Patens in No , No , No , No , No , No , No , No , No No , No , No , No , No , No , No , No , No , No , No , No , No , and a U. S. Design NO [0003] As can be known from the above data regarding to the chainless transmit device for bikes, their arts generally have no mutual adaptability, all not compatible to common conventional chain transmit style bikes, needing an exclusive bike body to install a chainless transmit device on a bike, impossible to be adapted to common conventional bikes. The main impasse lies in the shafts of the gears having the axle (the axles of a large and a small gear engaging with each other are aligned in the same horizontal line). So the bike body has to be changed or remodeled in order to fix a chainless transmit device on the conventional bike, limiting their adaptability and versatility. SUMMARY OF THE INVENTION [0004] This invention has been devised to offer a chainless transmit device for bikes, adaptable to common conventional chain transmit bikes without need to change a bike body, only to fix a chainless transmit device on the conventional bike, very convenient to adapt. [0005] The main feature of the invention is a front bevel gear unit, a rear bevel gear unit, and a connecting means provided between the front and the rear bevel gear unit to transmit revolution of a large bevel gear rotated by the shaft of the pedal to a large bevel gear fixed on the shaft of a rear wheel so as to rotate the rear wheel. BRIEF DESCRIPTION OF DRAWINGS [0006] This invention will be better understood by referring to the accompanying drawings, wherein: Figure 1 a side view of a conventional chain transmit bike; Figure 2 is a side view of a conventional chain transmit bike replaced with a chainless transmit device in the present invention; Figure 3 is an upper view of a chainless transmit device for a bike assembled on a bike in one way in the present invention; and, Figure 4 is an upper view of a chainless transmit device for a bike assembled on a bike in another way in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0007] A preferred embodiment of a chainless transmit device for a bike in the present invention, as shown in Fig. 2 is fixed on a conventional bike having chain transmit device replaced with the chainless transmit device in the invention, without changing or modifying the body of the bike. [0008] The chainless transmit device for a bike includes a front bevel gear unit, a rear bevel gear unit 4, a flexible transmit means 5 or a hard transmit means 6 connecting the front bevel gear unit 2 and the rear bevel gear unit 4. [0009] The front bevel gear unit 2 consists of a large bevel gear 21 and a small bevel gear 22 engaging with each other, and a housing hiding them. [0010] The rear bevel gear unit 4 consists of a large bevel gear 41 and a small bevel gear 42. [0011] Figs. 3 and 4 show two ways by which the chainless transmit device is fixed on a body of a bike. The large bevel gear 21 is fixed on the shaft of a pedal, with the sloped gear surface facing inside, engaging the sloped gear surface of the small gear 22, so their axles are not on a same horizontal line, but cross each other in a right angle. Then an output shaft of the small bevel gear 22 is connected with a first flexible transmit means 5 or a first hard transmit means 56 to transmit revolution of the small bevel gear 22. [0012] The large bevel gear 41 of the rear bevel gear 4 is fixed on the shaft of a rear wheel, engaging the small bevel gear 42, which has its input shaft connected to a second flexible transmit means 5 or a second hard transmit means 6. Then the first and the second flexible means 5, 5 or the second hard transmit means 6, 6 are connected with each other with a coupling means 3 to transmit revolution of the front bevel gear 2 to the rear bevel gear to rotate the rear wheel. [0013] The chainless transmit device in the invention has the following advantages, as can be understood by the aforesaid description. 1. It is compatible with a common conventional chain transmit bike, by replacing the large chain wheel with the front bevel gear unit and the small chain wheel of the rear wheel with the rear bevel gear unit without changing or moderating \the body of the conventional bike. 2

3 3 EP A A bile with the chainless transmit device may be manufactured or the conventional chain transmit bikes may be converted in chainless transmit bikes. 3. It can break through the limit of a special body to adapt it on a common conventional bike. 4. It can save the investment for manufacture of chainless transmit bikes, enhancing industrial worthiness and benefit, offering the right for owners of common conventional chain transmit bikes to convert them into chainless transmit ones. While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications, which may fall within the spirit and scope of the invention The chainless transmit device for bikes as claimed in Claim 1, wherein said rear small bevel gear has its input shaft connected to said second hard transmit means. Claims 1. A chainless transmit device for bikes comprising a front bevel gear unit, a rear bevel gear unit, said front bevel gear unit having a large bevel gear fixed on the shaft of a pedal and engaging a small bevel gear, said rear bevel gear unit having a large bevel gear fixed on the shaft of a rear wheel of a bike and engaging a small bevel gear, said front small bevel gear having its output shaft connected with a first flexible transmit means or a first hard transmit means connected with a second flexible transmit means or a second hard transmit means connected to said rear small bevel gear so as to transmit revolution of said front bevel gear unit to said rear bevel gear unit, permitting rotation of said pedal rotate said rear wheel to let said bike run, and characterized by said front large bevel gear and said front small bevel gear not engaging with a center to a center but by a sloped gear surface to another sloped gear surface, in other words, the axles of both said front bevel gears being not on a same horizontal surface, and so being the axles of both said rear bevel gears not on the same horizontal surface The chainless transmit device for bikes as claimed in Claim 1, wherein said front small bevel gear has its output shaft connected with said first flexible transmit means The chainless transmit device for bikes as claimed in a claim, wherein said front small bevel gear has its output shaft connected to said first hard transmit means The chainless transmit device for bikes as claimed in Claim 1, wherein said rear small bevel gear has its input shaft connected to said second flexible transmit means. 55 3

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