Abstract: Two hooks are adjustable in position along a cylindrical bar for engaging operating elements in a vehicle, thereby preventing operation of the vehicle. One hook is fixed to an end of the bar. The other hook includes a yoke having arm ends pivotable about the bar. A lock body is captured between the yoke arm ends for pivoting about the bar. A spring wound under tension on the bar has one end attached to the yoke and the other end attached to the lock body. Pivoting of the lock body relative to the yoke, releases the spring, allowing sliding of the hook along the bar. A lock is mounted on the lock body for securing the lock body in a position in which the spring is under tension on the bar, thereby preventing movement of the hook along the bar.

Abstract: A compact self-blimped motion picture camera is achieved by mounting all drive train components on a mounting frame which together with a truncated conical lens support floats within the camera body. The lens support includes a forward annular lens mount and a generally cylindrical section the rear end of which is affixed to the mounting frame. The lens support is truncated in a 45.degree. plane that intersects the cylinder periphery just rearward of the lens mount and intersects the lens support rear end plane in a line that crosses the cylindrical axis. A rotating shutter and mirror assembly includes a sector-shaped mirror that rotates in a plane immediately behind the lens support truncation plane. Noise is minimized by using only belt and pulley drive components and only sleeve bearings.