Abstract: Attainment of a predetermined stress in a bolt (10) which is being tightened is indicated by interference with the freedom of a pin (15) to rotate relative to the bolt. The pin extends along a bore (14) from an end of the bolt and the bore lies in that part of the bolt which presents the minimum diameter of the bolt. The invention is especially useful for detecting when the stress to which the bolt is subjected exceeds the elastic limit of the bolt, because the radial contraction of the bore which then occurs is large, relative to the contraction which occurs during elastic deformation of the bolt.

Abstract: A soft-release lever-operated control system for parking brake cables is disclosed including a helical main clutch spring arrangement permitting movement of the operating lever only toward the brake-engaged position, and a release device for releasing the main clutch spring to permit return of the operating lever toward the brake-released position. According to another embodiment of the invention, a second helical clutch spring arrangement is provided that is activated when the operating cable is returned to the brake-released position, thereby to activate a cable tension adjusting device that removes slack contained in the inner brake cable operating member. According to a further embodiment, a push-to-release arrangement including a toggle pawl and spring device is operable upon tapping of the operating lever to place the system in a brake-released condition.