Telescopic column

Abstract

The invention relates to a telescopic column with one outer and at least one inner rod element capable of telescoping relative to each other, where at least the outer rod element surrounds at least one ball arrangement with at least one ball, which acts as a rolling bearing between the outer and inner rod elements during telescoping movement. In order to create a telescopic column which, while having a low weight and low manufacturing costs, displays high lateral stability, the at least one inner rod element is provided with a longitudinal groove, which surrounds part of the circumference of at least one ball of the ball arrangement and serves as a ball guide. The longitudinal groove can provide two or more laterally separated running surfaces for the at least one ball. An area with a larger radial distance can be provided on at least one rod element between adjacent running tracks for an assigned ball, this being able to act as an abutment for the ball in the manner of an overload protector.

Patent claims:  
     
         1 . A telescopic column with one outer and at least one inner rod element capable of telescoping relative to each other, where at least the outer rod element surrounds at least one ball arrangement with at least one ball, which acts as a rolling bearing between the outer and inner rod elements during telescoping movement, characterized in that the at least one inner rod element displays a longitudinal groove which surrounds part of the circumference of the at least one ball of the ball arrangement and serves as a ball guide.  
     
     
         2 . A telescopic column according to  claim 1 , characterized in that the longitudinal groove provides at least two laterally separated running surfaces for the at least one ball.  
     
     
         3 . A telescopic column according to  claim 2 , characterized in that the inside of the outer rod element surrounds part of the circumference of the at least one ball and provides at least two more laterally separated running surfaces for the at least one ball.  
     
     
         4 . A telescopic column according to  claim 3 , characterized in that an area with a larger radial distance is provided on at least one rod element between adjacent running surfaces for an assigned ball constituting an overload protector in the form of an abutment for the ball.  
     
     
         5 . A telescopic column according to  claim 2 , characterized in that the laterally separated running surfaces of a groove of the radially inner and/or outer rod element enclose an angular range of the respectively guided ball of approx. 50 degrees to approx. 120 degrees.  
     
     
         6 . A telescopic column according to  claim 1 , characterized in that the at least one rod element is manufactured from a metal sheet or a section of tubing by a rolling method and the groove is an impression made in the sheet or section of tubing.  
     
     
         7 . A telescopic column according to  claim 1 , characterized in that the rod elements each have two or more laterally and/or axially separated guide areas for at least one given ball arrangement and that the at least one ball arrangement displays two or more balls separated in the lateral and/or axial direction or is suitable for accommodating two or more balls separated in the lateral and/or axial direction.  
     
     
         8 . A telescopic column according to  claim 1 , characterized in that at least one ball displays a slight oversize referred to its target position in disassembled condition of the telescopic column and, as a result of at least the first telescoping movement, impresses a running surface for the intended purpose in the inner and/or outer of the rod elements capable of telescoping relative to each other.  
     
     
         9 . A telescopic column according to  claim 8 , characterized in that the ball is located in a longitudinal groove of at least one of the inner and outer rod elements and two laterally separated running surfaces are impressed in the longitudinal groove of at least one of the inner and outer rod elements by means of a telescoping movement.  
     
     
         10 . A telescopic column according to  claim 9 , characterized in that the ball impresses at least two laterally spaced running surfaces in one of the inner and outer rod elements and at least one running surface in the corresponding of the inner and outer rod elements by means of a telescopic movement.  
     
     
         11 . A telescopic column according to  claim 8 , characterized in that the impressed running surfaces are provided with pre-machined running grooves for the balls, where the balls are pre-machined to the oversize of the ball existing in disassembled condition of the telescopic column.  
     
     
         12 . A telescopic column according to  claim 1 , characterized in that at least one of the inner rod elements essentially displays a polygonal profile and the at least one longitudinal groove is provided in the corner area of the profile.  
     
     
         13 . A telescopic column according to  claim 1 , characterized in that at least three rod elements capable of telescoping relative to each other are provided, which are at least partially designed as hollow profiles in the groove area and in that the rear side of the groove of the hollow profile of at least one rod element serves as a guide for a ball lying radially farther inwards, which forms the rolling bearing for the directly adjacent, radially inner rod element.  
     
     
         14 . A telescopic column according to  claim 13 , characterized in that at least three rod elements capable of telescoping relative to each other are provided, where two or more essentially groove-like ball guides are formed consecutively in radial direction, and in that the connecting axis of the center points of the balls guided in the guides lies outside the center point of the telescopic column.  
     
     
         15 . A telescopic column according to  claim 1 , characterized in that two or more rod elements capable of telescoping relative to each other are provided and in that, at least in pairs, the outer cross-section of an inner rod element essentially corresponds to the inner cross-section of the respective outer rod element.  
     
     
         16 . A telescopic column according to  claim 1 , characterized in that guide elements that absorb forces acting laterally on the rod elements, at least after slight angling of the rod elements relative to each other, are provided in the longitudinal direction of the rods, above and/or below at least one ball arrangement on adjacent rod elements.  
     
     
         17 . A telescopic column according to  claim 16 , characterized in that at least one guide element is provided that can be fixed in position on the assigned rod element by means of a snap-in connection and engages at least one corner of a rod element designed as a polygonal profile and/or a groove area of a rod element.  
     
     
         18 . A telescopic column according to  claim 1 , characterized in that at least one ball retainer is provided that displays at least two retaining areas, which are assigned to axially and/or laterally separated balls or ball arrangements and in that the ball retainer extends over one side wall of an assigned rod element.  
     
     
         19 . A telescopic column according to  claim 1 , characterized in that at least one rod element is provided with at least two ball retainers with retaining areas for running balls which extend over only part of the circumference of the assigned rod element and in that the ball retainers are located in diametrically opposite positions on the rod element.