Abstract: An electromotive variable-speed and control drive particularly for use in industrial sewing machines comprising a motor capable of continuous drive with a disk flywheel and a brake-coupling unit connected to this motor. Cooling ribs confining cooling channels are disposed at the stator frame to achieve efficient cooling. A disk flywheel in the form of a fan is in the form of an axial-radial blower the suction area of which extends to the coupling surface of the disk flywheel. Furthermore, particularly intensive cooling of the brake end shield is possible.

Abstract: An electromotive variable-speed and control drive particularly for use in industrial sewing machines and comprising a coupling coil casing radially surrounding a coupling-brake disk and a brake coil casing radially relocated towards the center. Both are positioned in the brake end shield. In order to avoid a sticking of the coupling-brake disk with high alternations and a delay of the break-down and build-up of the magnetic fields, a brake coil casing has been relocated radially so near to the center that it is situated within the brake pad in front of the armature ring. On the other hand, there is an undercut and a recess at the coupling coil casing and a recess at the disk flywheel which assures that no axial forces can occur at the radial gaps.

Abstract: An electromotive control drive mechanism, in particular for industrial sewing machines, comprises a continuously drivable motor and a brake/clutch unit connected therewith. A clutch disk connected in a rotationally fixed manner with a driven shaft can, by axial movement and by overcoming a clutch air gap, be brought into frictional engagement with a clutch support which is connected in a rotationally fixed manner with the rotor of the motor. A brake disk connected in a rotationally fixed manner with the driven shaft can be brought into frictional engagement with a brake support which is rotationally fixed. A clutch coil and a brake coil are also provided. In order to reduce the expense of the brake/clutch unit without burdensome actuation noises arising, only one clutch/brake disk is provided, and mechanisms are provided for adjusting the clutch air gap and the automatic readjustment of the clutch air gap.

Abstract: An electromotive control drive mechanism, in particular for industrial sewing machines, comprises a continuously drivable motor and a brake/clutch unit connected therewith. A clutch disk connected in a rotationally fixed manner with a driven shaft can, by axial movement and by overcoming a clutch air gap, be brought into frictional engagement with a clutch support which is connected in a rotationally fixed manner with the rotor of the motor. A brake disk connected in a rotationally fixed manner with the driven shaft can be brought into frictional engagement with a brake support which is rotationally fixed. A clutch coil and a brake coil are also provided. In order to reduce the expense of the brake/clutch unit without burdensome actuation noises arising, only one clutch/brake disk is provided, and mechanisms are provided for adjusting the clutch air gap and the automatic readjustment of the clutch air gap.

Abstract: An arrangement for energy economy in a drive which includes an induction motor and a clutch-brake unit, particularly for sewing machines is provided. The windings of the induction motor are dimensioned so that the motor speed remains virtually constant in a stable speed range under normal service conditions, and in which the clutch-brake unit serves to control the drive output speed, so that the motor operates in an alternation of load phases and no-load phases. Switches are included in the current paths of the windings, which reduce the current through the windings to a prescribable degree. A modulation circuit to control the acceleration of the motor speed and its persistence in the stable speed range during load variations is associated with the switches. The modulation circuit contains a delay element, which is triggered when the mains voltage is applied, and an impulse prolongation element having a time constant dimensioned so that the motor remains in the stable speed range under all service conditions.