A window crank (10) has a rotary knob (12) consisting of plastic. This has a cylindrical bearing element (22) which is mounted in a hollow hub (20) of the crank arm (11). For this purpose, use is made of two separate bearing points (25, 45), whose spacing (d) corresponds approximately to the bearing diameter (D). Cutouts (46) with lubricant are located in one of the bearing points (45). The cylindrical bearing element (22) has a conical portion (47), and the hollow hub (20) has resilient elements (50) which bear against said conical portion (47). <IMAGE>
