Patent ID: 7997160

Claim:
A control device for controlling engagement of a selected gear of a gearbox for a motor vehicle, the control device comprising a holder unit, at least one control rod, the control rod is arranged and operable for linear movement in the holder unit, and a locking arrangement operable to cooperate with the control rod, the locking arrangement is configured to define one or more predetermined setting positions of the control rod relative to the holder unit, the locking arrangement comprising: the holder unit including a locking element having a hollow interior defined by a peripheral wall in which one or more grooves or recesses are formed at intervals along the peripheral wall, and each groove or recess defines a predetermined setting position of the control rod relative to the holder unit along the linear movement of the control rod relative to the locking element; the control rod having a hollow space defined therein extending along a longitudinal axis of the control rod; two locking balls disposed in the hollow space in the control rod, the hollow space being sized and shaped and the locking balls being sized such that the locking balls are radially movable in the hollow space in respective directions perpendicular to the control rod's longitudinal axis, while the control rod is configured to prevent longitudinal direction movement of the locking balls relative to the control rod; a spring in the hollow space and biasing against the locking balls for urging the locking balls radially toward a respective protruded position in which each locking ball engages in one of the grooves/recesses in the locking element for resisting longitudinal movement of the control rod relative to the locking element, and permitting the locking balls to move radially to a retracted position in which the locking balls do not engage in any of the grooves/recesses in the locking element; and a control ball disposed in and movable in the hollow space in the control rod's axial direction and preloaded by the spring to be biased against the locking balls so that the locking balls are urged by the spring to be preloaded to assume the protruded position, and the control ball is also operable under the influence of the locking balls and against the action of the spring to move axially in the hollow space in response to movement of the locking balls from the protruded position to the retracted position; and the locking balls and the control ball are of the same size as one another.