Ball coupling assembly for steering column assembly

Abstract

A steering column assembly for an autonomous or semi-autonomous vehicle includes a steering wheel and an upper steering shaft rigidly coupled to the steering wheel. Also included is a lower steering shaft operatively coupled to the upper steering shaft. Further included is a ball coupling assembly comprising balls retained within the upper steering shaft, the balls disposed in a first radial position that engages the balls with the upper steering shaft and the lower steering shaft to place the steering shafts in a coupled condition, the balls disposed in a second radial position that disengages the balls from at least one of the upper steering shaft and the lower steering shaft to place the steering shafts in a decoupled condition.

Having thus described the invention, it is claimed: 
     
       1. A steering column assembly for an autonomous or semi-autonomous vehicle having a steering wheel, the assembly comprising:
 an upper column steering shaft rigidly coupled to the steering wheel; 
 a lower column steering shaft operatively coupled to the upper column steering shaft; and 
 a ball coupling assembly for switching the upper column steering shaft and the lower column steering shaft between a coupled condition and a decoupled condition, the ball coupling assembly comprising:
 a plurality of balls retained within the upper column steering shaft; 
 a plurality of pockets circumferentially spaced from each other and defined by the lower column steering shaft, each of the pockets sized to receive a portion of one of the plurality of balls; 
 a collar surrounding the balls, the collar having an angled portion of an inner wall disposed in contact with the balls; and 
 a collar actuating mechanism for selectively axially translating the collar between a coupled condition and a decoupled condition, the collar actuating mechanism further comprising: 
 a driving structure engaged with the collar; and 
 a linkage coupled to the driving structure to axially translate the collar. 
 
 
     
     
       2. The steering column assembly of  claim 1 , wherein the linkage is secured to a column housing structure of the steering column assembly. 
     
     
       3. The steering column assembly of  claim 1 , wherein the collar includes a magnet located proximate the inner wall to attract the balls radially outwardly to the second radial position. 
     
     
       4. The steering column assembly of  claim 1 , wherein the upper and lower steering column shafts are switched between the coupled condition and the decoupled condition with a user input device. 
     
     
       5. The steering column assembly of  claim 4 , wherein the user input device comprises one of a button, a switch and a voice prompt system. 
     
     
       6. A steering column assembly for an autonomous or semi-autonomous vehicle having a steering wheel, the assembly comprising:
 an upper column steering shaft rigidly coupled to the steering wheel; 
 a lower column steering shaft operatively coupled to the upper column steering shaft; and 
 a ball coupling assembly for switching the upper column steering shaft and the lower column steering shaft between a coupled condition and a decoupled condition, the ball coupling assembly comprising:
 a plurality of balls retained within the upper column steering shaft; 
 a plurality of pockets circumferentially spaced from each other and defined by the lower column steering shaft, each of the pockets sized to receive a portion of one of the plurality of balls; 
 a collar surrounding the balls, the collar having an angled portion of an inner wall disposed in contact with the balls; and 
 a collar actuating mechanism for selectively axially translating the collar between a coupled condition and a decoupled condition, wherein the balls are disposed at a first radial position that disposes the balls within the pockets to place the upper and lower column steering shafts in the coupled condition, the balls disposed at a second radial position that removes the balls from the pockets to place the upper and lower column steering shafts in the decoupled condition, the coupled condition providing common rotation of the upper and lower column steering shafts and the decoupled condition permitting independent rotation of the upper and lower column steering shafts, the steering column assembly further comprising an annular recess defined by the lower column steering shaft, the annular recess extending to a radial depth that is less than a radial depth of the plurality of pockets, the balls free to rotate along the annular recess when the balls are in the second radial position, the collar actuating mechanism further comprising an actuator engaged with a linkage to actuate movement of the linkage. 
 
 
     
     
       7. The steering column assembly of  claim 6 , wherein the actuator comprises an electric solenoid biasing the linkage in a first state of the solenoid to position the balls in the first radial position, the electric solenoid switchable to a second state to allow the balls to move to the second radial position. 
     
     
       8. The steering column assembly of  claim 7 , wherein the collar actuating mechanism further comprises a spring axially biasing the driving structure to position the balls in the second radial position when the electric solenoid is in the second state. 
     
     
       9. A steering column assembly for an autonomous or semi-autonomous vehicle having a steering wheel, the assembly comprising:
 an upper column steering shaft rigidly coupled to the steering wheel; 
 a lower column steering shaft operatively coupled to the upper column steering shaft; and 
 a ball coupling assembly for switching the upper column steering shaft and the lower column steering shaft between a coupled condition and a decoupled condition, the ball coupling assembly comprising:
 a plurality of balls retained within the upper column steering shaft; 
 a plurality of pockets circumferentially spaced from each other and defined by the lower column steering shaft, each of the pockets sized to receive a portion of one of the plurality of balls; 
 a collar surrounding the balls, the collar having an angled portion of an inner wall disposed in contact with the balls; and 
 a collar actuating mechanism for selectively axially translating the collar between a coupled condition and a decoupled condition; and 
 
 an electric solenoid having a pin extending therefrom, the pin engageable with a receiving hole defined by the upper column steering shaft to rotationally lock the steering wheel when the upper and lower column steering shafts are in the decoupled condition. 
 
     
     
       10. A steering column assembly for an autonomous or semi-autonomous vehicle having a steering wheel, the assembly comprising:
 an upper column steering shaft rigidly coupled to the steering wheel; 
 a lower column steering shaft operatively coupled to the upper column steering shaft; and 
 a ball coupling assembly for switching the upper column steering shaft and the lower column steering shaft between a coupled condition and a decoupled condition, the ball coupling assembly comprising:
 a plurality of balls retained within respective holes defined by the lower column steering shaft in a single axial plane; 
 a central pin disposed within a bore of the lower column steering shaft and axially translatable therein; 
 an annular recess defined by the central pin; and 
 a central pin actuating mechanism for axially translating the central pin, the balls disposed at a first radial position that disposes the balls within the annular recess to place the upper and lower column steering shafts in a decoupled condition, the balls disposed at a second radial position that disposes the balls in abutment with a radially outer surface of the central pin and within the holes of the lower column steering shaft and holes of the upper column steering shaft to place the upper and lower column steering shafts in a coupled condition, the coupled condition providing common rotation of the upper and lower column steering shafts and the decoupled condition permitting independent rotation of the upper and lower column steering shafts. 
 
 
     
     
       11. The steering column assembly of  claim 10 , further comprising an electric solenoid having a pin extending therefrom, the pin engageable with a receiving hole defined by the upper column steering shaft to rotationally lock the steering wheel when the upper and lower column steering shafts are in the decoupled condition. 
     
     
       12. The steering column assembly of  claim 10 , wherein the central pin actuating mechanism further comprises:
 a collar disposed between the upper column steering shaft and a column housing structure and operatively coupled to the central pin; 
 a driving structure engaged with the collar; and 
 a linkage coupled to the driving structure to axially translate the collar and the central pin. 
 
     
     
       13. The steering column assembly of  claim 12 , wherein the linkage is secured to the column housing structure of the steering column assembly. 
     
     
       14. The steering column assembly of  claim 12 , wherein the collar actuating mechanism further comprises an actuator engaged with the linkage to actuate movement of the linkage. 
     
     
       15. The steering column assembly of  claim 14 , wherein the actuator comprises an electric solenoid biasing the linkage in an first state of the solenoid to position the balls in the first radial position, the electric solenoid switchable to a second state to allow the balls to move to the second radial position, the upper and lower steering column shafts switchable between the coupled condition and the decoupled condition with a user input device comprising one of a button, a switch and a voice prompt system. 
     
     
       16. The steering column assembly of  claim 15 , wherein the collar actuating mechanism further comprises a spring axially biasing the driving structure to position the balls in the first radial position when the electric solenoid is in the first state.