Abstract: A moving element which forms a sliding carriage comprises a housing with several pairs of guiding balls supported therein, which balls are arranged for contacting and rolling on guiding surfaces of a guide means. Each guiding ball is supported by a roller bearing and is rotatable around the axis of said bearing when travelling along a guiding surface contacting the same along a little circle of its surface. The guiding balls are positioned in groups, each group of balls forming a set to provide a form-locked support transversely to the guiding direction. One ball of each set is elastically biased against the respective guiding surface. Therefore the roller bearing of said ball is mounted axially displaceable and is supported by a spring washer against an adjusting screw in said housing. Thereby a compensation of play is achieved without making necessary a precise machining of the guide.

Abstract: The spindle bearing for the spindle shaft relative to a support to be shifted has at least one pivoted roller. The roller is geared by its peripheral groovings into a thread of the spindle shaft. In order to keep the required precision of the feed during an appearance of heavy loads in the axial direction, the roller and the spindle shaft are supported against each other in such a way, that the relative position of axes of the roller and of the spindle shaft remains unchanged during the action. The roller is adjustably supported crosswise to the spindle shaft through needle bearings, taking up axial and radial forces, in order to achieve a complete freedom from play.

Abstract: A filter, mainly for coffee-making devices, comprises a cup-shaped cylindrical member and a circular member partially closing the top aperture of the cup-shaped cylindrical member so as to leave a filter-forming circular gap therebetween. This gap increases in width from the inner edge of the cup-shaped member inwards; the top face of the circular member may constitute the bottom of the filtration chamber. Means may be provided for adjusting the relative spacing of these members and therefore the width of the filter-forming gap. Ribs or shims may be provided on either of the two members for maintaining a permanent gap width.