Abstract: A speed change device has an input member rotatable in opposite directions to transmit higher torque as its rotation angle becomes larger, and a variable angle-ratio change mechanism including rollers and teethed wheels that are arranged in parallel to each other. The rollers and teethed wheels are respectively connected to rotate together with each other. The teeth of the wheels have a clearance on a pitch circle between their adjacent teeth so that the clearance is larger than a slip amount of the rollers in a low torque range where the rollers transmit low torque with bypassing the wheels in a normal operation. The wheels are engaged with each other to transmit high torque in a high torque range where the high torque is applied in an exceptional operation and the rollers slip larger than the slip amount in the low torque range.

Abstract: A speed change device has an input member rotatable in opposite directions to transmit higher torque as its rotation angle becomes larger, and a variable angle-ratio change mechanism including rollers and teethed wheels that are arranged in parallel to each other. The rollers and teethed wheels are respectively connected to rotate together with each other. The teeth of the wheels have a clearance on a pitch circle between their adjacent teeth so that the clearance is larger than a slip amount of the rollers in a low torque range where the rollers transmit low torque with bypassing the wheels in a normal operation. The wheels are engaged with each other to transmit high torque in a high torque range where the high torque is applied in an exceptional operation and the rollers slip larger than the slip amount in the low torque range.

Abstract: A method for searching the magnetic stripe on a credit card to determine the indispensably read out track comprising the steps of reading a card number from any one of the several tracks, determining if the credit card has an indispensably read out track already decided by the issuer of the card, reading out a track number for indispensable data from memory if such read out track has been decided, reading out indispensable data from the read out track using the track number, reading out a track searching mode on a priority basis from memory if such read out track has not been decided, reading out a first priority track which is known by the mode for the credit card, determining the read out data as being indispensable if no reading error occurs, and sending the indispensable data to a host computer for business transactions. The method is accomplished by apparatus for reading data from the tracks, for identifying the indispensably read track, and for performing the business transactions.