Freewheel for a bicycle

• Main Authors: OI, TAKESHI, LIM, PUAT THIAM
• Format: Patent
• Language: English; French; German
• Published: 21.03.2001
• Edition: 7
• Subjects: BEARINGS; BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; CYCLES; ELEMENTS OR CRANKSHAFT MECHANISMS; ENGINEERING ELEMENTS AND UNITS; FLEXIBLE SHAFTS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS; LIGHTING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; POWERED PROPULSION OF SLEDGES OR; RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; ROTARY BODIES OTHER THAN GEARING ELEMENTS; SHAFTS; THERMAL INSULATION IN GENERAL; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES; TRANSPORTING; WEAPONS

A freewheel (15) is provided for mounting a plurality of sprockets (21-27) on an axle of a bicycle (1). The freewheel (15)basically includes an inner tubular body (16), an outer tubular body (17) coaxially mounted on the inner tubular body (16) with a bearing assembly (18) rotatably coupling the inner tubular body (16) to the outer tubular body (17). A one-way clutch (20) is coupled between the inner tubular body (16) and the outer tubular body (17) to allow one-way rotation between the inner (16) and outer (17) tubular bodies. In the preferred embodiment, seven sprockets (21-27) are mounted on the exterior of the outer tubular body (17). The bearing assembly (18) has a pair of ball bearing races of the same diameter located at one end. An outer ball race or housing (70) and a side plate (73) are utilized in conjunction with the inner tubular body (16) to fixedly secure the first (71) and second (72) ball bearings on the exterior surface of the inner tubular body (16). The inner tubular body (16) with the bearings (71,72) is then fixedly coupled to the outer tubular body (17) so that the outer tubular body (17) can rotate relative to the inner tubular body (16). The one-way clutch (20) includes a pair of pawls (92) attached to the inner tubular body (16) and a set of ratchet teeth (59) formed on the inner tubular body (16). The ratchet teeth (59) are rotated between splines (58) that are formed on the exterior surface of the outer body so as to maximize strength and minimize material. The outer tubular body (17) has a step-shaped configuration with a plurality of abutment stoppers (56) formed on the splines (55) of the largest section such that some of the sprockets (21-27) are installed from one direction and the other sprockets (21-27) are installed in a second direction.