A method for operating a clutch in a power tool having an electric motor having an open-loop and closed-loop control device for closed-loop and open-loop control of motor power of the tool, and having a sensor, wherein the tool is operable in a first or second operating mode; in the first mode, the clutch is actuated after a predetermined time if a predetermined rotational speed threshold is undershot, and in the second mode, the clutch is actuated if a first predetermined motor current threshold value is exceeded. The method comprises setting the second mode; measuring the current of the motor; and reducing the motor rotational speed from a first rotational speed value to a second rotational speed value if a second predetermined current threshold value is exceeded, wherein a torque that can be generated by the tool is increased from a first torque value to a second torque value.

A method for operating a clutch in a power tool having an electric motor having an open-loop and closed-loop control device for closed-loop and open-loop control of motor power of the tool, and having a sensor, wherein the tool is operable in a first or second operating mode; in the first mode, the clutch is actuated after a predetermined time if a predetermined rotational speed threshold is undershot, and in the second mode, the clutch is actuated if a first predetermined motor current threshold value is exceeded. The method comprises setting the second mode; measuring the current of the motor; and reducing the motor rotational speed from a first rotational speed value to a second rotational speed value if a second predetermined current threshold value is exceeded, wherein a torque that can be generated by the tool is increased from a first torque value to a second torque value.

An engine-driven working machine according to the present invention has a controller and a muffler. The controller is operated from starting of the engine in a rotational speed limitation mode in which the engine is prevented from rotating at a rotational speed that is higher than the predetermined limitation rotational speed. The controller forces to stop the engine, after a predetermined period has passed, during which the engine operates in the rotational speed limitation mode.

The HUMAN POWERED FLYWHEEL DRIVE SYSTEM is a vehicle drive system utilizing a flywheel positioned concentrically within an air sealed space inside a drive wheel, so as to rotate in a coaxial configuration with both the drive wheel and flywheel rotating independently until the drive wheel is propelled to between a ten and fifteen mile per hour speed, when the rotation of the drive wheel is coupled to that of the flywheel so as to purpose stored energy for added momentum and torque. Braking is applied only to the drive wheel while allowing the flywheel to remain spinning freely to store energy.

The HUMAN POWERED FLYWHEEL DRIVE SYSTEM is a vehicle drive system utilizing a flywheel positioned concentrically within an air sealed space inside a drive wheel, so as to rotate in a coaxial configuration with both the drive wheel and flywheel rotating independently until the drive wheel is propelled to between a ten and fifteen mile per hour speed, when the rotation of the drive wheel is coupled to that of the flywheel so as to purpose stored energy for added momentum and torque. Braking is applied only to the drive wheel while allowing the flywheel to remain spinning freely to store energy.

A safety coupling has a driving coupling member engaged with a driven coupling member by a frictional connection. The frictional connection can be disconnected by activation of a release element. The release element can be activated by a centrifugal device wherein a centrifugal unit of the centrifugal device is radially moveable to interact with a shift gate in dependence of the revolution speed of the centrifugal unit and the slip between the driving coupling member and the driven coupling member. The centrifugal device includes a stop to limit the centrifugal force applied to the centrifugal unit.

It is preferable to reduce an uncomfortable feeling arising from an abrupt driving force generated in an automatic starting clutch in an automatic clutch vehicle. When an automatic clutch operating device is about to automatically engage a starting clutch, a brake controller drives a brake actuator to forcibly actuate a brake device, thereby braking a driving wheel WR. Here, a brake pressure to be applied to the driving wheel WR can be set as a brake pressure such as to change an expected driving torque which is accompanied by an uncomfortable feeling in the absence of control by the brake controller into a norm driving torque which is not accompanied by the uncomfortable feeling, taking into account the clutch capacity and an engine control output.

It is preferable to reduce an uncomfortable feeling arising from an abrupt driving force generated in an automatic starting clutch in an automatic clutch vehicle. When an automatic clutch operating device is about to automatically engage a starting clutch, a brake controller drives a brake actuator to forcibly actuate a brake device, thereby braking a driving wheel WR. Here, a brake pressure to be applied to the driving wheel WR can be set as a brake pressure such as to change an expected driving torque which is accompanied by an uncomfortable feeling in the absence of control by the brake controller into a norm driving torque which is not accompanied by the uncomfortable feeling, taking into account the clutch capacity and an engine control output.

An actuator includes housing having a reciprocation axis, drive gear configured to couple to the motor, and electromagnetic clutch configured to couple to the motor and coupled to the drive gear. The clutch engages first and second clutch plates responsive to being powered and disengages the clutch plates responsive to not being powered. Actuator includes a ball screw including a nut and a threaded shaft. The nut is coupled to the drive gear and rotation of the drive gear induces rotation of the nut about the reciprocation axis. Rotation of the nut induces motion of the threaded shaft along the reciprocation axis. Actuator includes a fluid damper having a piston coupled to the threaded shaft and disposed within a chamber containing a fluid. Piston includes a port that couples a first chamber portion to a second chamber portion. A brake assembly limits rotation of the nut responsive to the assembly being engaged.

An actuator includes housing having a reciprocation axis, drive gear configured to couple to the motor, and electromagnetic clutch configured to couple to the motor and coupled to the drive gear. The clutch engages first and second clutch plates responsive to being powered and disengages the clutch plates responsive to not being powered. Actuator includes a ball screw including a nut and a threaded shaft. The nut is coupled to the drive gear and rotation of the drive gear induces rotation of the nut about the reciprocation axis. Rotation of the nut induces motion of the threaded shaft along the reciprocation axis. Actuator includes a fluid damper having a piston coupled to the threaded shaft and disposed within a chamber containing a fluid. Piston includes a port that couples a first chamber portion to a second chamber portion. A brake assembly limits rotation of the nut responsive to the assembly being engaged.