Drive assembly for rotary mower or the like

A drive assembly for a rotary mower or the like providing automatic de-clutching and braking of the mower blade when the device is left unattended which comprises, in combination, a frame, a drive shaft, an annular blade carrier having means for securing a blade to its underside, an anti-friction bearing mounting the blade holder for rotation at the lower end of the drive shaft, a drive hub secured to the drive shaft at a level above the anti-friction bearing, the lower end of the drive shaft being threaded for reception of a threaded clamping member for securing the hub and bearing rigidly to the shaft in stacked relation, an axially shiftable shell of upwardly facing hollow bowl shape surrounding the drive hub with an axial opening for clearing the drive shaft and defining a clutch space, a stack of clutch discs of annular shape mounted on the hub in the clutch space, the stack including a set of driving clutch discs keyed to the hub and an interposed set of driven clutch discs keyed to the interior of the shell, interengaging means for keying the blade holder to the under surface of the shell, a set of biasing springs interposed between the blade carrier and the shell for urging the shell upwardly in a direction to apply clutching pressure to the stack of clutch discs so that torque is transmitted from the shaft through the shell and the carrier for driving the blade, the shell having an annular outwardly extending flat lip about its upper edge presenting an upwardly facing friction surface, an annular brake plate arranged above the friction surface with its edge portion registering therewith, means mounting the brake plate on the frame for movement toward and away from the friction surface on the shell, means for coupling the brake plate to the frame to resist rotational drag, means for pressing the brake plate downwardly against the friction surface on the shell for (1) braking rotation of the shell and blade and (2) shifting the shell downwardly against the force of the biasing springs for releasing clutching pressure upon the clutch discs so that the blade is stopped, and a manual control member arranged for convenient gripping by the operator during normal operation of the device for over-powering the pressing means and for holding the brake plate in an upraised position so that the blade is driven only as long as the control member is gripped.