Abstract: The invention relates to an obstacle for a driving training device comprising a unit which can be moved, essentially in a straight line, between a resting position and a working position. Accordingly, it is provided that the unit includes a flexible sleeve and a reset device for returning the sleeve to the resting position. Furthermore, the invention relates to a method for extending a spontaneously appearing and solid-looking object on a roadway using a driving training device that includes at least one obstacle with a unit that has a flexible sleeve and that is moved, essentially in a straight line, between a resting position and a working position. Accordingly, it is provided that the unit with the flexible sleeve is automatically moved to the working position and, if necessary, automatically returned to the resting position during an approach of a training vehicle to the driving training device.

Abstract: The invention relates to a thermal protection element (1), which is arranged on the front side for protecting a diaphragm (11) of a pressure sensor (10) to which pressure is applied. According to the invention, the thermal protection element (1) has, in the region of the sensor diaphragm (11), lamellae (2) which run parallel or are configured as circular arc segments (8) and cover 40% to 60% of the diaphragm surface, with the ratio between the cross-sectional height (h) of the lamellae (2) and the cross-sectional width (b) thereof being 8:1 to 12:1.

Abstract: The invention relates to a thermal protection element (1), which is arranged on the front side for protecting a diaphragm (11) of a pressure sensor (10) to which pressure is applied. According to the invention, the thermal protection element (1) has, in the region of the sensor diaphragm (11), lamellae (2) which run parallel or are configured as circular arc segments (8) and cover 40% to 60% of the diaphragm surface, with the ratio between the cross-sectional height (h) of the lamellae (2) and the cross-sectional width (b) thereof being 8:1 to 12:1.

Abstract: A piezoelectric pressure sensor which includes piezoelectric measuring elements is inserted in a housing having a membrane element located on the pressure side of the housing. The membrane element has a centered membrane stamp at the centre of a thin annular membrane. The piezoelectric measuring elements being radially disposed outwards from a prestressing element extending essentially along the longitudinal axis of the sensor, which prestressing element passes through the housing base, serves as a lead for the sensor signal and is attached to a pressure body at its end adjacent to the membrane. The centered membrane stamp is attached to the pressure body, and the prestressing element is prestressed against the housing base, having a gas-tight insulating element interposed. Furthermore, the pressure body is provided with a sealing shoulder which fits against a sealing seat in the interior of housing upon destruction of the measuring elements, thus forming a gas-tight zone.

Abstract: A piezoelectric sensor, preferably a pressure sensor, comprising at least two piezoelectric measuring elements placed in a housing, which are clamped between a membrane on the pressured side of the housing and a pick-up electrode electrically insulated against the housing. The piezoelectric measuring elements are fixedly attached to the pick-up electrode by thermo-compression or soldering and together with said pick-up electrode form a compact measuring element stack, which will significantly simplify assembly of the piezoelectric sensor.

Abstract: A piezoelectric sensor, preferably a pressure sensor, comprising at least two piezoelectric measuring elements placed in a housing, which are clamped between a membrane on the pressured side of the housing and a pick-up electrode electrically insulated against the housing. The piezoelectric measuring elements are fixedly attached to the pick-up electrode by thermo-compression or soldering and together with said pick-up electrode form a compact measuring element stack, which will significantly simplify assembly of the piezoelectric sensor.