The indexer was initially developed for bicycle gear shifting to keep rides within a predetermined pedaling cadence range.
A patented mechanical indexer indexes a fixed number of degrees when the motor input shaft reaches a preset speed. The initial 2.5-inch diameter model has five indexes and rotates through 17 degrees. For other models, the angle varies by the number of indices and size of the unit. When a preset speed is attained, a flyweight with a helical segment engages and interlocks with a helical thread on the inside bore of the housing. This action advances the output drum one index. If the input shaft drops a fixed amount below the present speed, the mechanism will index back to its original start position. If the input shaft speed drops to a speed between the advance and return speed, a ball-detent mechanism will stop indexing and hold position. The speed differential at which the indexer will advance, hold, or return is adjustable by changing the helix' circumferential position. Applications include advance or retard speed indexing such as on bicycle shift mechanisms.
Oliver Tysver, T DESIGN LTD, W76N1062 Hampton Ave; Cedarburg, WI 53012 Tel: (262) 375-8727; E-mail: firstname.lastname@example.org.
Samsung's Galaxy line of smartphones used to fare quite well in the repairability department, but last year's flagship S5 model took a tumble, scoring a meh-inducing 5/10. Will the newly redesigned S6 lead us back into star-studded territory, or will we sink further into the depths of a repairability black hole?
In 2003, the world contained just over 500 million Internet-connected devices. By 2010, this figure had risen to 12.5 billion connected objects, almost six devices per individual with access to the Internet. Now, as we move into 2015, the number of connected 'things' is expected to reach 25 billion, ultimately edging toward 50 billion by the end of the decade.
NASA engineer Brian Trease studied abroad in Japan as a high school student and used to fold fast-food wrappers into cranes using origami techniques he learned in library books. Inspired by this, he began to imagine that origami could be applied to building spacecraft components, particularly solar panels that could one day send solar power from space to be used on earth.
Biomedical engineering is one of the fastest growing engineering fields; from medical devices and pharmaceuticals to more cutting-edge areas like tissue, genetic, and neural engineering, US biomedical engineers (BMEs) boast salaries nearly double the annual mean wage and have faster than average job growth.
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