a ball locking mechanism for the releasable locking of a movable part comprises a locking or arresting ball arranged in at least one bore of a stationary or fixed part or component and can be pushed , by means of a slide member , into one of a number of bores of the movable part or element , so that such movable part can be locked in place . for unlocking , the slide member is displaced until a bore thereof comes to lie essentially coaxially with respect to the remaining bores . then , the ball moves out of the aforementioned one bore of the movable part . the movable part can then be displaced until a further similar bore thereof comes to lie essentially coaxially with respect to the bore of the fixed part . by means of the pressure of a spring , exerted upon the slide member , the ball then is again pushed into this further bore .