In the drawings, the same structural parts and structural parts with the same function are denoted by the same reference numerals.
 in figure 1 The marking and/or leveling device 1 is shown in a schematic diagram. The marking and/or leveling device includes a housing 2 and a pendulum 3 that is supported relative to the housing 2 so as to be deflectable relative to the housing 2 in all spatial directions. The pendulum 3 is configured as a rigid connecting rod element and carries a light source 4 configured as a laser diode on its lower end in the plane of the drawing, which is used to generate a laser beam 5 in a point or line shape along the cross section. With this laser beam, a point-like or linear horizontal laser line can be projected onto the projection plane.
 On the upper end of the light source 4 in the plane of the drawing, the hard pendulum 3 has a ball head 6 which forms a self-adjusting bearing 8 together with an annular bearing receiver 7. The bearing receiving portion 7 is firmly connected to the housing 2 and is penetrated downward by the pendulum 3 in the plane of the drawing. In other words, the ball head 6 is placed on the bearing receiving portion 7.
 in figure 1 , The pendulum 3 is located in a position different from the vertical direction without orientation. In order to orient the pendulum 3 vertically, a mechanism 9 shown only schematically is provided for impulsively accelerating the pendulum 3. In the illustrated embodiment, the mechanism 9 is arranged directly on the pendulum 3. As a supplement or alternative, the mechanism 9 can be arranged on the light source 4 or on the bearing receiving portion 7, that is to say on the self-adjusting bearing 8 (refer to the mechanism 9 drawn in dashed lines). It is also conceivable that all the aforementioned components are provided with a separate mechanism 9 for pulsed acceleration. In the simplest case, the mechanism 9 for pulsed acceleration of the pendulum 3 is constructed as an electric motor with an unbalanced part. If the mechanism 9 for pulsed acceleration of the pendulum 3 is activated, the mechanism is placed in vibration and undergoes a pulsed movement relative to the bearing receiver 7 and the housing 2, whereby the pendulum 3 With the light source 4 occupying its center of gravity, the pendulum 3 is oriented so that the light source 4 places a horizontal mark on the projection plane.
 in figure 1 In the illustrated embodiment, the bearing receptacle 7 of the self-adjusting bearing 8 simultaneously forms the non-adjustable element 10 of the (passive) braking device 11. In the pulse interval, the friction fit connection between the ball head 6 and the element 10 (bearing receiving portion 7) achieves rapid braking of the pendulum 3, so that the leveling time for the vertical orientation of the pendulum 3 is short.
 Pressing figure 2 In the embodiment, in addition to the self-adjusting bearing 8, a separate braking device 11 is also provided. The braking device includes a (brake) element 12 that can be adjusted actively, manually or automatically relative to the ball head 6 of the pendulum 3, and the element can be friction-fitted against the ball in the release position shown. The braking position on the head 6 is adjusted along the arrow direction 13. By adjusting the adjustable element 12 into the release position shown, the mechanism 9 for pulsed acceleration of the pendulum 3 is automatically activated, thereby placing the pendulum in vibration and positioning it relative to the housing. 2Twist in the self-adjusting bearing 8. The vibration of the pendulum 3 achieved by the mechanism 9 for pulsed acceleration is indicated by the arrow 14. Since the vibrating motion of the pendulum 3 overcomes the bearing friction of the self-adjusting bearing 8, and the restoring force 15 caused by gravity is sufficient to orient the pendulum 3 vertically, the horizontally and/or vertically-oriented light marks can be assisted by the light source 4 The light beam 5 is projected onto a projection plane not shown. As a supplement or alternative, the mechanism 9 can be arranged on the self-adjusting bearing 8 (refer to the mechanism 9 shown in dashed lines).
 in figure 1 with 2 The marking and/or leveling device 1 shown in FIG. 1 has a particularly robust construction compared to the marking and/or leveling devices disclosed in the prior art. In addition, the pendulum 3 is relatively short, so that the entire marking and/or leveling device 1 is constructed relatively low.