Abstract: A drive and control device for sewing machines, automatic sewing installations, and the like, with a recognition unit which responds for the purpose of end recognition when the sewing tools have approached a predetermined spacing from the desired seam end. The drive and control device also includes a preselection stitch counting unit, which can be triggered by means of the recognition unit, for the presetting of a predetermined number of remaining stitches still to be executed subsequently to the end recognition, and a correction unit for the performance of a stitch correction in dependence on the respective needle position at the instant of end recognition. The correction unit serves for automatically varying the length of at least one of the remaining stitches.

Abstract: Drive mechanism for working machines, especially industrial sewing machines, including a speed-controlled DC motor without a collector, the windings of this motor being supplied by way of a power stage having a full bridge circuit, actuated in dependence on the rotor position of the motor. A safety monitoring circuit responding to overcurrent is associated with the power stage in order to block the full bridge circuit in case of overload. The drive mechanism is furthermore provided with a microprocessor control for the positioning and ancillary functions of the driven working machine.

Abstract: The position adjusting drive unit for a sewing machine having its work shaft driven by an electromotor with an adjustable rotary speed, includes a supporting box connected to the electromotor and including a power supply transformer and an activation mechanism for a signal generator for desired and actual values of the rotary speed of the motor and of the angular position of the working shaft; an exchangeable printed circuit board supports all electrical and mechanical component parts of the speed regulating and angular position adjusting circuits including the signal generators and the coupling rod between the activation mechanism in the supporting box and the part of the activation mechanism on the circuit board is guided into the proper coupling position when the circuit board is electrically connected to the power supply transformer.

Abstract: A positioning drive for a serving machine of the type having a variable speed motor and functional means driven by the motor. A microprogram system controls the motor and the functional means in response to a program data source.

Abstract: The position adjusting drive unit for a sewing machine having its work shaft driven by an electromotor with an adjustable rotary speed, includes a supporting box connected to the electromotor and including a power supply transformer and an activation mechanism for a signal generator for desired and actual values of the rotary speed of the motor and of the angular position of the working shaft; an exchangeable printed circuit board supports all electrical and mechanical component parts of the speed regulating and angular position adjusting circuits including the signal generators and the coupling rod between the activation mechanism in the supporting box and the part of the activation mechanism on the circuit board is guided into the proper coupling position when the circuit board is electrically connected to the power supply transformer.

Abstract: A driving arrangement with a friction clutch has at least one clutch element arranged to transmit torque and forming a friction face, and at least one lubricating storing container carried by the clutch element and arranged for accommodating a lubricating medium and distributing the latter over the friction face. The clutch element may be provided with a friction member forming the friction face and constituted of cork. The lubricant storing container may be formed as a hollow ring whose hollow is connected with the friction face so as to provide a dosed passage or the lubricating medium to the latter.

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: 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.