A downhole motor (107) which comprises a stator housing (108), a rotor assembly (106) rotatable relative to said stator housing, and an arrangement for enabling, in use, a drill bit connected to the rotor assembly of said downhole motor to be rotated by rotating a drill string connected to said stator housing, wherein said arrangement comprises a unidirectional clutch (117) disposed between said rotor assembly and said stator housing and having at least one pawl which can be displaced between an inoperative position adjacent said stator housing and an operative position in which rotation of said stator housing by said drill string in one sense is transmitted to said rotor assembly via said at least one pawl, means biasing said at least one pawl towards said operative position, means retaining said at least one pawl in its inoperative position, and means which, when sufficient pulling force is applied to said drill string, will cause said means retaining said at least one pawl to release said at least one pawl and enable said at least one pawl to move into its operative position.

A downhole motor (107) which comprises a stator housing (108), a rotor assembly (106) rotatable relative to said stator housing, and an arrangement for enabling, in use, a drill bit connected to the rotor assembly of said downhole motor to be rotated by rotating a drill string connected to said stator housing, wherein said arrangement comprises a unidirectional clutch (117) disposed between said rotor assembly and said stator housing and having at least one pawl which can be displaced between an inoperative position adjacent said stator housing and an operative position in which rotation of said stator housing by said drill string in one sense is transmitted to said rotor assembly via said at least one pawl, means biasing said at least one pawl towards said operative position, means retaining said at least one pawl in its inoperative position, and means which, when sufficient pulling force is applied to said drill string, will cause said means retaining said at least one pawl to release said at least one pawl and enable said at least one pawl to move into its operative position.

An actuator controller to controllably supply DC power to a bi-directional electromechanical actuator is provided. The controller includes a first circuit to receive power and direction command signals from a remote electronic control unit through a vehicle-based bus. Control logic is operative to determine a vehicle system failure and to generate a failsafe position command signal in the event of the failure. A failsafe power circuit controllably stores electrical power and supplies the stored electrical power based on the failsafe position command signal. A power switching and supply circuit supplies DC power of a desired polarity to the electromechanical actuator in response to the power and direction command signals in the absence of the failure and supplies the stored electrical power to the electromechanical actuator in the event of the failure.

An actuator controller to controllably supply DC power to a bi-directional electromechanical actuator is provided. The controller includes a first circuit to receive power and direction command signals from a remote electronic control unit through a vehicle-based bus. Control logic is operative to determine a vehicle system failure and to generate a failsafe position command signal in the event of the failure. A failsafe power circuit controllably stores electrical power and supplies the stored electrical power based on the failsafe position command signal. A power switching and supply circuit supplies DC power of a desired polarity to the electromechanical actuator in response to the power and direction command signals in the absence of the failure and supplies the stored electrical power to the electromechanical actuator in the event of the failure.

An electro-mechanical clutch apparatus includes a stationary member (22,122) having a center portion extending along an axis A and a stationary coil assembly (34,134) fixed about the center portion. A rotatable member (46,146) extends along the axis A and includes an annular projection (52,152) radially spaced from the coil assembly. A ratchet surface (29,129) presents a plurality of teeth disposed in axially aligned and radially spaced relationship with the annular projection. The rotatable member includes a magnetic pole piece (62,162) disposed in radially spaced and concentrically aligned relationship with said coil assembly. The rotatable member includes a locking member (58,158) pivotably attached to the annular projection and pivotable between an engaged position in engagement with one of the teeth in response to the coil assembly being de-energized and a released position displaced from engagement with the teeth and attracted towards the magnetic pole piece in response to the coil assembly being energized.

A clutch for selectively preventing rotation of a rotating component may include a first and second pawls pivotable between engagement and disengagement with the rotating component to selectively prevent or allow rotation of the rotating component in one or both directions. An armature moveable between a first and second armature positions may have a common member pivotally connected thereto and engaging the first and second pawls, with a torque spring biasing the common member to rotate toward the first pawl and away from the second pawl. In an intermediate armature position, the common member may disengage the first pawl from the rotating component while engaging the second pawl to allow rotation in one direction while preventing rotation in the opposite direction. In embodiments, a clutch may include a cam actuator rotating to selectively control engagement of the pawls with the rotating component and locking in one or both directions.

A selectable one-way clutch comprises inside clutch elements and outside clutch elements. The inside clutch elements include: an inside pocket plate where inside pawl members are held; an inside notch plate where inside recesses to engage with the inside pawl members are formed; and an inside selector plate disposed between the inside pocket plate and the inside notch plate. The outside clutch elements include: an outside pocket plate where outside pawl members are formed; an outside notch plate where outside recesses to engage with the outside pawl members are formed; and an outside selector plate disposed between the outside pocket plate and the outside notch plate. The inside clutch elements and the outside clutch elements are disposed concentrically using one axial line as a center.

A selectable one-way clutch comprises inside clutch elements and outside clutch elements. The inside clutch elements include: an inside pocket plate where inside pawl members are held; an inside notch plate where inside recesses to engage with the inside pawl members are formed; and an inside selector plate disposed between the inside pocket plate and the inside notch plate. The outside clutch elements include: an outside pocket plate where outside pawl members are formed; an outside notch plate where outside recesses to engage with the outside pawl members are formed; and an outside selector plate disposed between the outside pocket plate and the outside notch plate. The inside clutch elements and the outside clutch elements are disposed concentrically using one axial line as a center.

A vehicle including a continuously variable transmission including a gear selectively locked to an output shaft via a clutch actuated by an electric coil. The vehicle also includes a controller configured to, in response to wheel hop being detected, energize the coil to disengage the clutch allowing the gear and the output shaft to rotate independently of each other.

A clutch includes a first race, a second race, a pawl, a post, and a shoe. The second race defines a cam surface. The pawl is supported in the first race to pivot between an engaged position and a disengaged position such that contact between the cam surface and the pawl in the engaged position prevents relative rotation between the first and second races in at least one direction. The post is supported in the first race to slide between a first and a second position such that in the first position the post forces the pawl into the disengaged position. The shoe is configured to pivot with respect to the first race in response to a magnetic field to slide the post into the second position.