Abstract: A skateboard includes a deck and a plurality of trucks connected to an underside of the deck. Each truck includes two shafts and two wheels are rotatably connected to the two shafts. At least one active device is connected to a top of the deck and controlled by user's foot. The at least one active device drives a driving member which is connected to a brake cable of at least one brake device so that the user can brake the wheels by the control from his or her feet.

Abstract: A skateboard includes a deck with two trucks connected to an underside of the deck and each truck has a case with two axles so that two rollers are rotatably connected to the two axles. Two protection members are connected to the two cases respectively and at least one cushion member is connected between respective one of the protection members and respective one of the cases. A rolling shaft is connected each of the two protection members and includes a mediate section which extends out from an opening of the protection member corresponding thereto so as to provide smooth grinding.

Abstract: A formula processor which computes results for a group of formulas in which at least one formula uses the result of another formula. The formula processor receives the formulas from a host and returns computed results for the formulas to the host for storage in a main memory. Formulas are received as a sequence of tokens, each token describing operands or operations. The formula processor is pipelined; as one token is interpreted and processed by the formula processor, subsequent tokens are received. The formula processor uses a computation element which is capable of performing only certain operations; before attempting each operation described by a token, the computation element determines whether the operation can be performed by the computation element--if it can be performed, it is; otherwise, the host may perform the operation itself, or rewrite the operation so the formula processor can perform it. After the formula processor computes a result for a formula, it stores this result in a cache memory.