Automatic mini-bike transmission

Abstract

Abstract AN AUTOMATIC TWO-SPEED TRASMISSION FOR MINI-BIKE AND OTHER LIGHT-WEIGHT VEHICLES. A FIRST CENTRIFUGAL MAIN CLUTCH ON THE ENGINE SHAFT DRIVES PARALLEL CHAINS TO HIGHAND LOW-SPPED SPROCKETS ON A JACK SHAFT WHICH IS CHAINCONNECTED TO THE DRIVE-WHEE. THE LOW-SPEED SPROCKET DRIVES THE JACK SHAFT THROUGH A ONE-WAY, ROLLER "LOW" CLUTCH OF STUDY 4-ROLLER CONSTRUCTION, WHICH ALLOWS THE JACK SHAFT TO OVERRUN WHEN THE HIGH DRIVE ENGAGES. THE HIGH-SPEED SPROCKET DRIVES THE CLUTCH SHOES OF A SECOND CETRIFUGAL "HIGH" CLUTCH WHICH HAS ITS CLUTCH DRUM FIXED TO THE JACK SHAFT. THE HIGH-CLUTCH SHOES ARE PRIMARILY CENTRIFUGALLY RESPONSIVE, BUT ARE ARRANGED TO HAVE LIMITED SELF-ENRGIZING ACTION AND THEREBY TO MAINTAIN SMOOTH ENGAGEMENT AND RELEASE AS TRANSITION HANGES OCCUR DURING SHIFTS. THE COMBINATION GIVES RELIABLY PREDICTABLE SHIFTS IN RESPONSE TO DRIVE CONTROL OF ENGINE SPEED, AND SMOOTH TRANSITIONS BETWEEN LOW DRIVE AND HIGH DRIVE. THE JACK SHAFT ASSEMBLY COMPRISES A CONTINUOUSLY SLOTTED SHAFT ON WHICH THE CLUTCHES, SPROCKETS, A BRAKE DRUM, AND SUPPORTING BEARINGS ARE MOUNTED IN AXIALLY ADJUSTABLE RELATION TO ADAPT SUCH ASSEMBLY FOR VERSATILE APPLICATION TO DIFFERENT BIKE STRUCTURES AND FOR USE AS A MODIFICATION KIT ON EXISTING BIKES.

Inventors

• 👤 Stephen J Hoff

Bibliographic Details