Blind riveting apparatus and methods

1. A friction stir blind riveting apparatus comprising:

a motor, wherein the motor is a driven motor;

a clamp for gripping a mandrel of a blind rivet, the clamp being movable along the axis of the mandrel;

a first transmission configured, when engaged, to transfer rotary motion of the motor to the clamp so as to cause rotary motion of the clamp;

a second transmission configured, when engaged, to convert rotary motion of the motor to linear motion of the clamp, and thereby retract the clamp to pull on the mandrel, when engaged;

a transmission control apparatus arranged to selectively adjust the degree of engagement of at least one of the first and second transmissions, the transmission control apparatus comprising a variable-influence brake or clutch; and

wherein an amount of slip the brake or clutch permits while the motor is being driven can be varied from no slip at all permitted, to slip being completely unrestricted, and anywhere in between.

2. The blind riveting apparatus of claim 1 wherein the transmission control apparatus is arranged to selectively adjust the degree of engagement of both the first and second transmissions.

3. The blind riveting apparatus of claim 2 wherein the second transmission comprises a first threaded member connected to the motor and a second threaded member connected to the clamp, the threads of the first and second threaded members being arranged to directly or indirectly act on each other to convert rotation of the first threaded member relative to the second threaded member into linear motion of the second threaded member.

4. The blind riveting apparatus of claim 3 , wherein the transmission control apparatus is configured to engage the first transmission by rotationally coupling the first and second threaded members so as to restrict relative rotation therebetween, and is configured to engage the second transmission by restricting rotation of the second threaded member so that relative rotation of the first and second threaded members takes place.

5. The blind riveting apparatus of claim 2 wherein the transmission control apparatus is arranged to selectively adjust the degree of engagement of said first transmission and/or second transmissions to any degree of engagement within the operable range of the first transmission and/or second transmission.

6. The blind riveting apparatus of claim 2 wherein the transmission control apparatus is arranged to selectively adjust the degree of engagement of said first transmission and/or said second transmission between fully disengaged and fully engaged states.

7. The blind riveting apparatus according to claim 1 wherein the transmission control apparatus comprises a variable-influence brake system.

8. The blind riveting apparatus according to claim 7 wherein the variable-influence brake system comprises a volume of magneto-rheological or electro-rheological fluid retained in a cavity between a rotationally fixed component and a rotational component, the variable-influence brake system further comprising an electric or magnetic field generator arranged to selectively apply an electric or magnetic field to the volume of fluid in order to alter the viscosity of the fluid.

9. The blind riveting apparatus according to claim 7 wherein the transmission control apparatus is configured to selectively adjust the degree of engagement of the second transmission by controlling the amount of slip permitted by the variable-influence brake system.

10. A blind riveting apparatus according to claim 1 further comprising:

a nose tip configured to support the body of said blind rivet; and

a third transmission configured, when engaged, to convert rotary motion of the motor into linear motion of at least the nose tip, wherein the transmission control apparatus is arranged to also selectively adjust the degree of engagement of the third transmission.

11. A blind riveting apparatus according to claim 10 , wherein the second transmission is comprised within the third transmission.

12. A blind riveting apparatus according to claim 10 wherein the third transmission comprises a first threaded member connected to the motor and a second threaded member connected to the nose tip, the threads of the first and second threaded members being arranged to directly or indirectly act on each other to convert rotation of the first threaded member relative to the second threaded member into linear motion of the second threaded member.

13. The blind riveting apparatus of claim 1 wherein the apparatus further comprises a nose piece which is configured to engage with the blind rivet, the clamp being arranged to rotate the rivet by rotationally driving the nose piece.

14. The blind riveting apparatus of claim 13 wherein the apparatus further comprises a controller configured to monitor a performance of the apparatus via one or more sensors.

15. The blind riveting apparatus according to claim 1 wherein the transmission control apparatus comprises a one-directional clutch.

16. The blind riveting apparatus of claim 1 wherein the apparatus further comprises a controller configured to gather feedback on a status or dynamic performance of the apparatus via one or more sensors, and calculate and/or implement real-time adjustments to said status or dynamic performance of the apparatus.

17. The blind riveting apparatus according to claim 1 , wherein the variable-influence brake or clutch is a mechanical variable-influence brake or clutch.