Abstract: A magnetic encoder system (2) of a sewing machine drive comprises a disk (5), which is magnetized, an incremental track (8) and a reference track (9). The incremental track (8) extends completely around the disk (5) and has alternating pole elements (10), which serve as incremental markings. The reference track (9) is designed as a ring-shaped section on the disk (5) and has a monopole (11). The result is a magnetic encoder system (2), for example for a servo motor of a sewing machine.

Abstract: An electric motor comprises a flange at one end, the corner portions of the flange projecting over the outline of the stator. A ventilator is provided at the opposite end, having outlets which are in alignment with the corner portions. The ventilator does not project over the borderline of the flange.

Abstract: A flange motor for a sewing machine comprises a motor casing with a drive shaft journal projecting over the latter. A casing flange, on which an adapter flange is mounted, is allocated to the drive shaft journal.

Abstract: In a position indicating device, especially for an industrial sewing machine, with a slotted wheel (3) and a first track (6) of slots (4) having, e.g., 512 slots (4), to permit a null-point synchronization over a relatively small range of rotational angles, and the establishment of definite angular positions, a second track (8) with slots (7) of various widths is provided. The first track (6) of slots (4) is associated with two light barrier arrangements comprising emitters (11a, 11b), receivers (12a, 12b), and masks (13a, 13b) while the second track (8) is associated with one light barrier arrangement. Evaluating systems are connected to the receivers (12) so that, on the basis of the number of slots (4) of the first track (6), the size of the slots (7) passing in each case and corresponding approximately to a multiple of the slot width may be determined through evaluating systems (14, 28) connected to the output, and in this manner to define the rotary angle position.

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: In a clutch-and-brake unit for use with a continuously rotating, motor-driven shaft, for example in an industrial sewing machine, a single disk has a clutch surface on one side and a brake surface on the other side. The disk is magnetically urged into operative engagement with clutch and brake pressure plates facing the respective clutch and brake surfaces of the disk, the clutch pressure plate being rotated by the motor-driven shaft to rotate the disk and a shaft connected thereto when operatively engaged, and the brake pressure plate being non-rotatable to brake the shaft. The brake pressure plate is also constantly urged into light contact with the brake surface sufficient to brake the disk and shaft only when the disk is not operatively engaged with the clutch pressure plate. This prevents the disk and connected shaft from rotating when neither the clutch nor the brake are operatively engaged and eliminates engagement noise when the brake pressure plate is operatively engaged.

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.

Abstract: An arrangement for securing a housing cover, especially useful for securing a cover for a switch box having electrical switching devices therein includes at least one screwable element which can be threaded to the housing and which is secured undetachably on the cover by a stop on its shaft. The shaft extends through the cover, each of the screwable elements extending through a bottom of an indentation in a surface of the cover. A pre-stressed compression spring is disposed in the indentation between a shoulder of the screwable element and the base of the indentation. Each screwable element comprises a shaft nut, the shaft nut having a shaft with an indentation in its pressure-receiving face. The shaft engages with a threaded pin attached to the housing and rests against a structural part which is supported against a support attached to the housing. The screwable element is centered by a centering body positioned directly ahead of the support on the threaded pin.

Abstract: An actuation apparatus for a control switch which, in accordance with the position of a switching member, produces various control signals, in which an actuation arm coupled with the switching member is provided. The actuation arm is pivotable out of a central position of rest about a pivoting shaft counter to the restoring force of a torsion spring provided with free arms. A respective stationary initial stop is provided for each arm for the purpose of fixing the arm position in the position of rest and in which at least one coupler in contact with the free arms is connected with the actuation arm. At least one second stop, which acts as an end stop, is operatively associated with each free arm of the torsion spring to define the end of the switching paths.

Abstract: A circuit board arrangement which is to be disposed in a housing closable by a cover or hood has a plugged connector, which has plug prongs for effecting electrical connections of circuitry attached to the housing. The plug connector is secured on a rim portion of the circuit board. The plug connector is disposed on the side of the circuit board oriented towards the cover. The plug prongs extend perpendicular to the main plane of the circuit board, plug sockets opening toward an outer face of the plug connector remote from the circuit board. The outer face is located in an opening in the cover. The plug connector is an insulating body substantially L-shaped in cross-section having one free end of the longer L-arm supported on the circuit board and having a shorter L-arm pointing towards the adjacent circuit board rim portion. The plug connector has U-shaped plug prongs extending through its longer L-arm and its shorter L-arm.

Abstract: A contactless synchronizer for sewing machines has been developed. This synchronizer contains at least two transmitting elements which rotate with the sewing machine shaft and indicate the angular position of the machine with respect to stationary sensing elements. These sensing elements form a part of the entire circuit of the machine and produce control pulses as each transmitting element passes a sensing element.