Abstract: The drive shaft of a motor can be coupled to an output shaft by an electromagnetically activated friction clutch. The output shaft can be braked by an electromagnetically activated friction brake. The motor drive shaft rotates at constant speed. The rotary speed of the output shaft is regulated by negative-feedback action to maintain a selected value, by activating the clutch and brake alternately as necessary. The activating signals for the clutch and brake are pulse-width-modulated activating signals. The output shaft can be stopped in at least one predetermined angular position when commanded to do so. The movable parts of the brake and clutch are of minimal mass, and the speed-regulating system includes a speed feedback transducer system of very high resolution.

Abstract: The drive shaft of a motor can be coupled to an output shaft by an electromagnetically activated friction clutch. The output shaft can be braked by an electromagnetically activated friction brake. The motor drive shaft rotates at constant speed. The rotary speed of the output shaft is regulated by negative-feedback action to maintain a selected value, by activating the clutch and brake alternately as necessary. The activating signals for the clutch and brake are pulse-width-modulated activating signals. The output shaft can be stopped in at least one predetermined angular position when commanded to do so. The movable parts of the brake and clutch are of minimal mass, and the speed-regulating system includes a speed feedback transducer system of very high resolution.

Abstract: A sewing machine has a main drive shaft to which is drivingly coupled the output member of a coupling motor unit, the latter including an electric motor having a constantly rotating output shaft, a braking structure, and electrically controlled electromagnets for causing the output member to engage and become disengaged from the output shaft and the braking structure to increase and decrease the rpm of the main drive shaft of the machine. An rpm regulator has first and second inputs for receipt of a desired-rpm command signal and an actual-rpm feedback signal. The actual-rpm feedback signal is generated using a pole wheel rotating synchronously with the sewing-machine drive shaft and a plurality of pick-up transducers spaced along the pole-wheel periphery. During pole-wheel rotation, an A.C. voltage is induced in each such pick-up transducer. The spacing of the transducers relative to the spacing of the poles of the pole wheel is such that these induced voltages are phase-shifted relative to one another.

Abstract: An electric coupling and brake motor comprises a continuously rotating main or drive shaft of the motor and an output shaft coaxially therewith, on which a cylindrical coupling member is coaxially mounted for rotation therewith and axially immovable with respect thereto. A flywheel is mounted on the drive shaft for rotation therewith and axially movable with respect thereto and facing one of the end faces of the coupling member, and a brake abutment member is mounted in the motor housing movable only in axial direction toward and away from the other end face of the coupling member. The motor includes further electromagnet means for selectively moving the flywheel or the brake abutment member in axial direction into frictional engagement with the respective end face of the coupling member to rotate the output shaft together with the drive shaft or to hold the output shaft stationarily during rotation of the drive shaft.

Abstract: A machine is comprised of at least one machine part, such as a rotating shaft, which moves cyclically during performance by the machine of first and second operations. The machine also includes a controlled unit which undergoes changes of state for the purpose of initiating and terminating machine operations. A control system for the machine includes a synchronizer for generating synchronizing pulses synchronized with the cyclical movement of the cyclically moving machine part. There is provided a first automatic control arrangement for automatically controlling performance by the machine of the first operation by counting synchronizing pulses generated during such first operation and upon reaching a first predetermined count causing the controlled unit to undergo a change of state, the first automatic control arrangement thereafter becoming inoperative.

Abstract: A transmitter for determining the speed of rotation and the angular position of a rotating member, such as a shaft, in which a coding disc is driven synchronously with the shaft and has a series of circularly distributed light and dark areas which cooperate with two sections of alternating light and dark areas formed by a coding segment which is fixed relative to the disc. The pitch of the light and dark areas of the coding segment is equal to the pitch of the light and dark areas of the coding disc, respectively, and the light and dark areas of one section of the coding segment are staggered relative to the light and dark areas of the other section thereof. A light is passed towards the coding disc and the coding segment and at least one photosensitive receiver is in the path of the light passing through the light areas for generating an output signal.

Abstract: A stator is mounted in a housing, and a rotor is rotatable with reference to the stator and rotates with a motor shaft. A flywheel is mounted on and rotatable with the motor shaft. An output shaft is separate from the motor shaft and a stationary member is mounted in the housing and surrounds the output shaft with clearance. A coupling plate and a braking plate are both mounted on the output shaft for rotation therewith, being located axially adjacent the flywheel and the stationary member, respectively. A first electromagnet is associated with the coupling plate and when energized causes frictional engagement of the latter with the flywheel so that the coupling plate and thereby the output shaft are entrained in rotation by the flywheel. A second electromagnet is associated with the braking plate and when energized causes frictional engagement thereof with the stationary member so that the braking plate and the output shaft are braked by frictional engagement therewith.