Abstract: At the electromagnetically controlled wrap around spring clutch a braking spring (14) designed as a wrap around spring is foreseen on the driven shaft (4) in addition to the clutch spring (8) acting between the driving shaft (3) and the driven shaft (4), which braking spring (14) is also switched by the control magnet (11), such that if the magnet is excited the driven shaft (4) is released, but at a currentless magnet the driven shaft (4) is immediately braked and blocked in the direction of the drive.

Abstract: A spring clutch includes a driving hub attached to a drive shaft, a driven hub to which a mass to be rotated is attached, and first and second helical clutch springs which are engageable to interconnect the driving hub and the driven hub, the first helical clutch spring including a first portion of smaller diameter which is in preloaded contact with the driven hub and a second portion of larger diameter which has a radially outwardly-extending end, and the second helical clutch spring being in preloaded contact with the driving hub and including a radially outwardly-extending end. A rotatable clutch sleeve is connected to the end of the first helical clutch spring and is movable by a pivot lever to interconnect the end of the first helical clutch spring with the end of the second helical clutch spring so that rotation of the second helical clutch spring will cause rotation of the first helical clutch spring and thus the driven hub.