Controllable coupling assembly and overrunning coupling and control assembly utilizing same

1. A controllable coupling assembly comprising:

first and second coupling members supported for rotation relative to one another about a common rotational axis, the first coupling member having a coupling first face oriented to face axially in a first direction along the rotational axis and the second coupling member having a coupling second face opposed to the first face and oriented to face axially in a second direction along the rotational axis, the second coupling member having a third face spaced from the second face and oriented to face axially in the first direction;

the second face having a set of pockets spaced about the rotational axis, each pocket of the set having a strut received thereby;

the first face having a set of locking formations that are engaged by the struts upon projecting outwardly from the set of pockets to prevent relative rotation of the first and second coupling members with respect to each other in at least one direction about the axis;

the third face having a set of passages spaced about the rotational axis and in communication with their respective pockets;

a control member mounted for controlled shifting movement along the rotational axis relative to the second coupling member between a first position which corresponds to a first mode of the coupling assembly and a second position which corresponds to a second mode of the coupling assembly;

a set of actuators supported on the control member to move therewith, each passage of the set of passages having an actuator received thereby to actuate its respective strut within its respective pocket so that its respective strut moves into contact with the locking formations to couple the first and second coupling members for rotation with each other in at least one direction about the rotational axis in one of the positions of the control member; and

at least one biasing member exerts a biasing force on the control member along the rotational axis wherein a control force causes the control member to move from its first position to its second position along the rotational axis against the biasing force of the at least one biasing member and wherein in the absence of the control force the at least one biasing member moves the control member from the second position back to the first position along the rotational axis.

2. The assembly as claimed in claim 1 , wherein each of the struts has an end that is pivotally movable outwardly of its respective pocket.

3. The assembly as claimed in claim 2 , further comprising a set of biasing members that bias their respective struts against pivotal movement of their respective ends out of their respective pockets toward the locking formations wherein the set of actuators pivot the ends of their respective struts against the bias of the set of biasing members and into contact with the locking formations to couple the first and second coupling members for rotation with each other in the at least one direction about the rotational axis and wherein the set of biasing members are configured to move the ends of each respective strut back into their respective pockets to permit relative rotation of the coupling members in the at least one direction about the rotational axis.

4. The assembly as claimed in claim 1 , wherein the at least one biasing member is disposed between the second coupling member and the control member to urge the control member towards its first position.

5. The assembly as claimed in claim 1 , wherein the first position is an overrun position, the first mode is an overrun mode, the second position is a locked position and the second mode is a locked mode.

6. The assembly as claimed in claim 1 , wherein the struts include at least one reverse strut and at least one forward strut.

7. The assembly as claimed in claim 6 , further comprising an element supported between the first and second coupling members, the element having at least one opening extending completely therethrough to allow the forward and reverse struts to extend therethrough at the same time and fully lock the coupling members together to prevent relative rotation between the coupling members in either direction about the rotation axis.

8. The assembly as claimed in claim 1 , wherein the third face has a set of formations spaced about the rotational axis and wherein the control member has a corresponding set of apertures for receiving the set of formations therein to guide the shifting movement of the control member.

9. The assembly as claimed in claim 1 , wherein the set of actuators includes springs.

10. The assembly as claimed in claim 1 , wherein the first, second and third faces are generally flat and face generally axially.

11. The assembly as claimed in claim 1 , wherein the first, second and third faces are generally annular and extend generally radially with respect to the rotational axis.

12. A controllable overrunning clutch assembly comprising:

first and second clutch members supported for rotation relative to one another about a common rotational axis, the first clutch member having a coupling first face oriented to face axially in a first direction along the rotational axis and the second clutch member having a coupling second face opposed to the first face and oriented to face axially in a second direction along the rotational axis, the second clutch member having a third face spaced from the second face and oriented to face axially in the first direction;

the second face having a set of pockets spaced about the rotational axis, each pocket of the set having a pivotal strut received thereby and a spring that privotally biases its strut inwardly therein;

the first face having a set of locking formations that are engaged by the struts upon pivoting outwardly from the set of pockets to prevent relative rotation of the first and second clutch members with respect to each other in at least one direction about the axis;

the third face having a set of passages spaced about the rotational axis and in communication with their respective pockets;

a control member mounted for controlled shifting movement along the rotational axis relative to the second clutch member between a first position which corresponds to a first mode of the clutch assembly and a second position which corresponds to a second mode of the clutch assembly;

a set of actuators supported on the control member to move therewith, each passage of the set of passages having an actuator received thereby to actuate its respective strut within its respective pocket so that its respective strut pivots into contact with the locking formations to couple the first and second clutch members for rotation with each other in at least one direction about the rotational axis in one of the positions of the control member; and

at least one biasing member which exerts a biasing force on the control member along the rotational axis wherein a control force causes the control member to move from its first position to its second position along the rotational axis against the biasing force of the at least one biasing member and wherein in the absence of the control force the at least one biasing member moves the control member from the second position back to the first position along the rotational axis.

13. The assembly as claimed in claim 12 , wherein the set of actuators pivot ends of their respective struts against the bias of their respective springs and into contact with the locking formations to couple the first and second coupling members for rotation with each other in the at least one direction about the rotational axis and wherein the springs are configured to move the ends of each respective strut back into their respective pockets to permit relative rotation of the coupling members in the at least one direction about the rotational axis.

14. The assembly as claimed in claim 12 , wherein the at least one biasing member is disposed between the second clutch member and the control member to urge the control member towards its first position.

15. The assembly as claimed in claim 12 , wherein the first position is an overrun position, the first mode is an overrun mode, the second position is a locked position and the second mode is a locked mode.

16. The assembly as claimed in claim 12 , wherein the struts include at least one reverse strut and at least one forward strut.

17. The assembly as claimed in claim 16 , further comprising an element supported between the first and second clutch members, the element having at least one opening extending completely therethrough to allow the forward and reverse struts to extend therethrough at the same time and fully lock the clutch members together to prevent relative rotation between the clutch members in either direction about the rotation axis.

18. The assembly as claimed in claim 12 , wherein the third face has a set of formations spaced about the rotational axis and wherein the control member has a corresponding set of apertures for receiving the set of formations therein to guide the shifting movement of the control member.

19. The assembly as claimed in claim 12 , wherein the set of actuators includes springs.

20. An overrunning coupling and control assembly comprising:

first and second coupling members supported for rotation relative to one another about a common rotational axis, the first coupling member having a coupling first face oriented to face axially in a first direction along the rotational axis and the second coupling member having a coupling second face opposed to the first face and oriented to face axially in a second direction along the rotational axis, the second coupling member having a third face spaced from the second face and oriented to face axially in the first direction;

the second face having a set of pockets spaced about the rotational axis, each pocket of the set having a strut received thereby;

the first face having a set of locking formations that are engaged by the struts upon projecting outwardly from the set of pockets to prevent relative rotation of the first and second coupling members with respect to each other in at least one direction about the axis;

the third face having a set of passages spaced about the rotational axis and in communication with their respective pockets;

a control member mounted for controlled shifting movement along the rotational axis relative to the second coupling member between a first position which corresponds to a first mode of the coupling assembly and a second position which corresponds to a second mode of the coupling assembly;

a set of actuators supported on the control member to move therewith, each passage of the set of passages having an actuator received thereby to actuate its respective strut within its respective pocket so that its respective strut moves into contact with the locking formations to couple the first and second coupling members for rotation with each other in at least one direction about the rotational axis in one of the positions of the control member;

at least one control member biasing member which exerts a biasing force on the control member along the rotational axis wherein a control force causes the control member to move from its first position to its second position along the rotational axis against the biasing force of the at least one control member biasing member and wherein in the absence of the control force the at least one control member biasing member moves the control member from the second position back to the first position along the rotational axis; and

apparatus responsive to a control pressure signal to exert the control force on the control member.

21. The assembly as claimed in claim 20 , wherein the apparatus includes:

a housing having an inner surface which defines a bore within the housing;

a hollow piston having an inner surface which defines a cavity, the piston including first and second piston parts disposed within the bore of the housing, the piston parts being movable relative to one another;

at least one piston biasing member disposed within the cavity which exerts a biasing force on the second piston part wherein a control pressure signal within the housing and against the outer surface of the second piston part causes the second piston part to move within the bore against the biasing force of the at least one piston biasing member until a portion of the second piston part exerts the control force on the control member.