摘要 |
A pneumatic spring is arranged with a view to putting a piece of electrical equipment into operation as soon as it reaches a given geometrical condition corresponding to a determined relative position of its piston rod, the device being equipped for this purpose with elastic strips which are arranged so as to be in contact at one time with the conducting wall of its tube, and to be separated from the latter at another time. The elastic contact strips are controlled by an insulating cam which is movable relative to them, and which is designed either to apply them against the wall of the tube if they are separated from it when at rest, or the reverse, that is to say to separate them from the wall of the tube if they are in contact with it when at rest. Such a spring can be used for automobiles. |