fig1 shows , firstly , a relevant section of an interior trim piece 1 , by way of example in the present case a dashboard of a vehicle , for example , a motor vehicle . the interior trim piece 1 has an opening 3 in a horizontal or substantially horizontal top covering surface 2 . however , the covering surface 2 need not be horizontal or substantially horizontal in its orientation , but instead can also deviate from the horizontal and / or can be curved in design . according to this exemplary embodiment , the opening 3 ensures the optical path of the light rays produced by means of a head - up display that is not shown in the drawing . as already explained above , a head - up display is understood to be an information display system in which the information is projected out of the interior trim piece 1 or the dashboard of the vehicle and through the opening 3 in the same into the field of view of the vehicle driver , for example onto a windshield or onto a separate so - called combiner screen of the vehicle ( not shown in the drawing ). by means of a displaceable cover element 4 here , the geometrical optical path of the light rays can be blocked and unblocked , or the opening 3 can be closed and opened . the cover element 4 is composed of a flat or substantially flat element and can be moved through travel thereof from an open position 4 a , in which the cover element 4 uncovers the opening 3 ( see fig1 and 2 , in particular ), to a closed position 4 b , in which the cover element 4 occupies or covers the opening 3 ( see fig3 - 5 , in particular ), and back again . in the present case , the cover element 4 is movable in such a manner that , during the opening process , it moves more or less along the opening 3 and below the covering surface 2 of the interior trim piece 1 that borders the opening 3 . in this process , the cover element 4 can be moved parallel to , at least in sections , or substantially parallel to the covering surface 2 . to this end , the cover element 4 is movably supported on a frame element 5 that is rigidly connected to the interior trim piece 1 , in the present case its covering surface 2 . the frame element 5 forms a rectangle that has two longitudinal struts 5 a , 5 b connected to one another by means of two transverse struts 5 c , 5 d . the longitudinal struts 5 a , 5 b are oriented in the longitudinal direction ( x - direction ) of the vehicle in this design . the frame element 5 additionally has so - called snap nuts 6 on the side facing the covering surface that serve to attach the frame element 5 to the interior trim piece 1 or to its covering surface 2 by means of mounting screws or the like , which are not shown in the drawing . in this design , the frame element 5 is placed against the covering surface 2 from below , and in this regard surrounds the opening 3 . in addition , a frame - like trim panel 7 is fastened to the frame element 5 from above , preferably through a catch mechanism , in particular so as to form a uniform surface together with the interior trim piece 1 or the dashboard . furthermore , a stiffener 8 is also associated with the frame element 5 ; it extends between the longitudinal struts 5 a , 5 b at the back of the frame element 5 in the manner of a cross - beam , and is fastened thereto as an add - on component by means of mounting screws 9 ( fig3 ). according to fig1 - 6 , the frame element 5 additionally has two lateral supports 10 , 11 that are orthogonal to a surface spanned by the frame element 5 or by its longitudinal and transverse struts 5 a - 5 d . viewed in the transverse direction of the vehicle ( y - direction ), the lateral supports 10 , 11 are spaced apart from one another and are each joined at one end to a longitudinal strut 5 a , 5 b of the frame element 5 , and are directed away from the covering surface 2 of the interior trim piece 1 proceeding from the frame element 5 . it is preferred for the frame element 5 , including the lateral supports 10 , 11 , to be implemented as a single piece , and further preferred for it to be made of a plastic using a plastic injection molding process . each of the free or bottom ends 10 a , 11 a of the lateral supports 10 , 11 has a bearing lug 12 , 13 . the bearing lugs 12 , 13 are arranged to be coaxial to one another . in each of the bearing lugs 12 , 13 , a pivoted lever 14 , 15 is supported at one end , or each at its bottom , first end 14 a , 15 a , so as to pivot about a common first pivot axis 16 . the pivoted levers 14 , 15 are supported at the other end , or at their top , second ends 14 b , 15 b , in bearings 17 , 18 of the cover element 4 so as to pivot about a common second pivot axis 19 . furthermore , the pivoted levers 14 , 15 are rigidly connected to one another by means of a transverse strut 20 , wherein the attachment of the pivoted levers 14 , 15 to the bearings 17 , 18 is accomplished indirectly through the transverse strut 20 in the present case . preferably the pivoted levers 14 , 15 , including the transverse strut 20 , are made of plastic as a single piece . it is further preferred for the bearings 17 , 18 to be provided on a first , in the present case front , end 22 (− x ) of the cover element 4 when viewed in the direction of travel 21 of the cover element 4 or in the longitudinal direction (± x - direction ) of the vehicle ( see fig2 , in particular ). as is very clearly evident from fig3 , and 6 , the cover element 4 has , viewed in the transverse direction ( y - direction ) of the vehicle , two bearing blocks 23 , 24 that are spaced apart from one another and are oriented toward the first pivot axis 16 . viewed in the direction of travel 21 of the cover element 4 or in the longitudinal direction (± x - direction ) of the vehicle , and proceeding from the bearings 17 , 18 , the bearing blocks 23 , 24 are arranged offset by a certain distance from a second , in the present case rear , end 25 (+ x ) of the cover element 4 . preferably the bearing blocks 23 , 24 are implemented as a single piece with the cover element 4 . a shaft 26 that is axially parallel to the first and second pivot axes 16 , 19 and passes through the bearing blocks 23 , 24 is rotatably supported in the bearing blocks 23 , 24 . a first gear 27 , 28 is arranged in a rotationally fixed manner at each of the free ends of the shaft 26 ( fig4 , in particular ). the first gears 27 , 28 mesh with a first gear rack 29 , 30 located on the applicable lateral support 10 , 11 . preferably the first gear racks 29 , 30 are implemented as a single piece with the lateral supports 10 , 11 , for example are molded onto the lateral supports 10 , 11 during the aforementioned plastic injection molding process . as can be seen from fig4 , in particular , the first gear racks 29 , 30 are designed to be congruent to one another . with regard to the first gears 27 , 28 that are rigidly attached to the shaft 26 , this results in synchronization of the two sides of the cover element 4 . as can be seen from fig2 , and 6 , in particular , the first gear racks 29 , 30 can be designed to be straight and / or curved , at least in sections . in advantageous fashion , this measure can be used to predefine a rolling contour of the first gear racks 29 , 30 or a travel path of the cover element 4 , for example a curved travel path , which ensures , during the opening process , that the cover element 4 drops below the sections of the covering surface 2 of the interior trim piece 1 that border the opening 3 . fig1 and 2 show a first variant embodiment of the first gear racks 29 , 30 to the effect that the teeth of the same face upward and the first gears 27 , 28 engage or are placed in the teeth more or less from above . in contrast , fig3 - 6 show a second variant embodiment of the first gear racks 29 , 30 such that the teeth of the same face downward and the first gears 27 , 28 engage or are placed in the teeth more or less from below . in order to further improve the positive guidance here of the cover element 4 that is already achieved by the first gear racks 29 , 30 , there is , adjoining each first gear 27 , 28 on the side facing the lateral support 10 , 11 , a guide block 31 , which preferably is rotationally symmetrical and rotates with the shaft 26 and the first gears 27 , 28 , which in turn is guided in a slide guide 32 of the applicable lateral support 10 , 11 ( fig3 and 6 ). the slide guides 32 in this design are parallel to the first gear rack 29 , 30 . the rotary motion of the rotationally symmetrical guide blocks 31 counters any stick - slip effect that may arise , but at a minimum the stick - slip effect can be efficaciously reduced . the slide guides 32 preferably are formed as a single piece with the associated lateral support 10 , 11 . to bring about the travel of the cover element 4 in one direction or the other (± x - direction ), at least one of the pivoted levers 14 , 15 , in the present case the left - hand pivoted lever 14 viewed facing forward in the vehicle (− x - direction ), is in operative connection with a pivot drive 33 . by means of the pivot drive 33 , a rotary motion or pivoting motion of the interconnected pivoted levers 14 , 15 is advantageously converted into a predominantly translational motion of the cover element 4 operatively connected to the pivoted levers 14 , 15 . the pivot drive 33 is composed of a motor , in particular an electric motor , fastened to the frame element 5 , or a motor / transmission block . in the present case , a motor / transmission block is shown as the pivot drive 33 . its output shaft , not visible , passes through the lateral support 10 associated with the pivoted lever 14 from the outside . as shown in fig3 , and 6 , a second gear 34 is arranged at the free end of the output shaft in a rotationally fixed manner . the second gear 34 meshes with a second gear rack 35 located on the pivoted lever 14 . in this design , the second gear rack 35 is composed of a sector of an internally toothed spur gear , and is preferably formed as a single piece with the pivoted lever 14 . furthermore , in the present case the second gear rack 35 is located in an approximately central region between the two ends 14 a , 14 b of the pivoted lever 14 . in order to prevent , or at a minimum to efficaciously reduce , adverse effects of any gear backlash that may be present , especially between the second gear 34 and the second gear rack 35 , at least one of the pivoted levers 14 , 15 is designed to be spring - loaded in the direction of pivoting . in the present case , a preloaded coil spring 36 that bears against the lateral support 10 at one end and against the pivoted lever 14 at the other end is located on the pivoted lever 14 . the invention being thus described , it will be obvious that the same may be varied in many ways . such variations are not to be regarded as a departure from the spirit and scope of the invention , and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims .