Abstract: An energy converter comprises a sleeve with a sleeve channel. A longitudinal groove is configured in the wall of the sleeve channel. A shank of a bolt is introduced into the sleeve channel. An L-shaped deformation member having an arresting leg is introduced into a lateral bore of the bolt shank, wherein then the sleeve leg comes to rest in the longitudinal groove of the sleeve and at the outer surface of the bolt shank. The sleeve and the bolt are thus secured against rotation. The bolt has a hexagonal bolt head, which can be positionally fixed in a matchingly configured aperture in the cheek of the belt fitting. If a predetermined force F acts upon the belt band, the sleeve and the bolt turn relative to one another and the deformation member pulls out of the longitudinal groove while rolling around the bolt shank.