shoe 10 in this area the support 5 is constructed in a dovetail configuration to which the segments 3 are pressed from both sides over the segments 3 the underwire 1 is shown on which an already partially dewatered fiber layer 28 is arranged which is covered by the upper wire 12 and which is moved in the direction 34 indicated by the arrow depicting the course of the machine as shown particularly in fig1 a device is provided which controls lubrication and cooling of the apparatus and thus prevents dry running thereof this control and cooling device consists of one or more detecting elements 40 which respond to moisture and or temperature and which are arranged at the outlet of the dewatering device a line 41 operates to transmit the sensed actual state detecting in the detecting elements 40 to an actual desired value converter and transmitter 42 which operates to regulate one or more valves 43 to provide a regulated quantity of water the water is emitted from a container 45 and is fed to the spraying pipes 6 by means of a pump 44 located in the line 26 thus it will be seen from the foregoing that the segments 3 in the area of the gap 4 are connected with the support 5 and are sealed with respect to the support 5 below the gap 4 which is formed by the segments 3 and which extends over the width of the paper machine there is provided a spraying pipe 6 arranged with a length that corresponds essentially to the width of the paper machine the machine is equipped with a cooling control device which consists of at least one of the detecting elements 40.