Abstract: An apparatus for varying the damping characteristics of a shock absorber of the kind comprising a piston rod and an adjusting shaft mounted coaxially within the piston rod for rotation relative to the piston rod. Upon a change in its angular position relative to the piston rod, the adjusting shaft effects a change in an effective oil passage area in the shock absorber, and thus varies its damping characteristics. The adjusting shaft (16) has a free end (15) located at the end of the piston rod. The apparatus comprises a housing (4, 18, 19, 50) arranged to be attached to the end of the piston rod. The housing accommodates, in succession: an electric motor (1) adapted to be driven and positioned in two directions; a speed reducer (2) coupled to an output shaft (26) thereof; and a universal joint (3) disposed between an output member (33) of the speed reducer (2) and the free end (15) of the shock absorber adjusting shaft (16).

Abstract: A method and apparatus for operating and monitoring the opening and closing cycle of electrically operated units such as electric windows and electric slide roofs which both eliminates the danger of body parts getting caught in the window and permits a complete opening and closing of the window automatically. In accordance with the invention, the speed of the drive motor is measured, directly or indirectly, and the first obtained measured value is compared with all following measured values. More particularly, this first measured value is used to detect momentary electrical and mechanical factors which change over the entire time of operation of the window, such as self-heating of the drive motor, the voltage charge of the battery, and the state and condition of the window. The processing or comparing of the measured values is carried out by a microcomputer. The actual measuring of the speed is by means of a sensor. The changes furnished by those sensors are utilized to determine the position of the window.

Abstract: An electrical circuit for controlling the operating of the relay of a fuel pump depending on the number of revolutions of the motor supplied by the fuel pump, whereby the fuel pump is cut off if the minimally permissible time interval being ignition pulses falls short, i.e., the number of revolutions of the motor exceeds an established value.