Torque overload clutch

1. In a torque overload clutch having an outer member and an inner member radially inward of said outer member, and at least one detent between said inner member and said outer member which maintains said members in rotational driving engagement with one another below a certain overload torque between said members, each said detent including a driving member that slides radially in an opening in said inner member between an engaged position in which said driving member is seated in a recess of said outer member in driving engagement with said recess and a disengaged position in which said driving member is retracted from said recess and said outer member is continuously rotatable relative to said inner member, said driving member being moved radially outward to engage in said recess by a mechanism including a spring that exerts an axial spring force that biases said driving member into said engaged position, the improvement wherein:

said driving member and said inner member are axially captured in the outer member by a ring that fits in a groove around a bore of the outer member, so as to limit compression of the spring by thrust loads placed on the inner member.

2. The apparatus as recited in claim 1 , wherein said inner member is splined for engagement with a shaft.

3. The apparatus as recited in claim 1 , further comprising a thrust bearing between said ring and said driving member.

4. The apparatus as recited in claim 3 , wherein the thrust bearing bears against an axially facing surface of the inner member.

5. The apparatus as recited in claim 1 , wherein said mechanism includes an actuator ring axially between said driving member and said spring, and said spring biases said actuator ring so as to cam said driving member on said actuator ring radially outwardly.

6. The apparatus as recited in claim 1 , wherein said spring is retained axially by a keeper, and said keeper is retained axially relative to the inner member by a ring that fits in a groove in an outer surface of the inner member.

7. In a torque overload clutch having an outer member and an inner member radially inward of said outer member, and at least one detent between said inner member and said outer member which maintains said members in rotational driving engagement with one another below a certain overload torque between said members, each said detent including a driving member that slides radially in an opening in said inner member between an engaged position in which said driving member is seated in a recess of said outer member in driving engagement with said recess and a disengaged position in which said driving member is retracted from said recess and said outer member is continuously rotatable relative to said inner member, said driving member being moved radially outward to engage in said recess by a mechanism including a spring that exerts an axial spring force that biases said driving member into said engaged position, the improvement wherein:

said driving member is seated in said recess in driving engagement with the outer member in one rotary direction of driving torque transmission so that the outer member and inner member can be turned relative to one another only above said certain overload torque, and so that in an opposite relative rotary direction the outer member and inner member can be turned relative to one another with a lower torque than said certain overload torque.

8. The apparatus as recited in claim 7 , wherein in the opposite relative rotary direction the driving member slides on a surface of the outer housing that is more gently sloped than a surface of the outer housing that the driving member slides on in the one rotary direction.

9. In a torque overload clutch having an outer member and an inner member radially inward of said outer member, and at least one detent between said inner member and said outer member which maintains said members in rotational driving engagement with one another below a certain overload torque between said members, each said detent including a driving member that slides radially in an opening in said inner member between an engaged position in which said driving member is seated in a recess of said outer member in driving engagement with said recess and a disengaged position in which said driving member is retracted from said recess and said outer member is continuously rotatable relative to said inner member, said driving member being moved radially outward to engage in said recess by a mechanism including a spring that exerts an axial spring force that biases said driving member into said engaged position, the improvement wherein:

said driving member and said inner member are axially captured in the outer member by a ring that fits in a groove around a bore of the outer member, so as to limit compression of the spring by thrust loads placed on the inner member; and

each driving member is seated in an associated recess in driving engagement for only one rotary direction of driving torque transmission, so that in the opposite rotary direction the outer member and inner member can be turned relative to one another with a lower torque than in the one rotary direction.

10. The apparatus as recited in claim 9 , wherein said inner member is splined for engagement with a shaft.

11. The apparatus as recited in claim 9 , further comprising a thrust bearing between said ring and said driving member.

12. The apparatus as recited in claim 11 , wherein the thrust bearing bears against an axially facing surface of the inner member.

13. The apparatus as recited in claim 9 , wherein said mechanism includes an actuator ring axially between said driving member and said spring, and said spring biases said actuator ring so as to cam said driving member on said actuator ring radially outwardly.

14. The apparatus as recited in claim 9 , wherein said spring is retained axially by a keeper, and said keeper is retained axially relative to the inner member by a ring that fits in a groove in an outer surface of the inner member.