Patent ID: 8608646
Filing Date: 2013-12-17
Classification: A61B

Abstract:
1. An endoscope comprising: an everting tube drive consisting of a drive tube everted twice which is encompassed by a drive device including drive means which are in frictional engagement with the drive tube so as to apply a feed force to the drive tube; and an endoscope shaft which is guided to slide in the drive tube and which forms a radial counter bearing for the drive means, the endoscope shaft comprising a composite tube, the composite tube further comprising an external tube having a wall, an internal tube having a wall and which is at least one of softer and more resilient than the external tube, and a helical spring mounted within the internal tube and adapted to radially press against the internal tube, for stiffening the composite tube; wherein the helical spring has windings and an outer diameter such that, in a relaxed state, the outer diameter is larger than an inner diameter of the internal tube, and the helical spring exerts a radially outwardly directed pressing force against a radially inner surface of the internal tube, the radial pressing force being sufficiently high that the helical spring windings impress a structure corresponding to the spring windings, to a radially outer surface of the external tube through the walls of the internal tube and the external tube.