Abstract: A method and an apparatus for closing an earth borehole, wherein an expandable closure body is inserted into the earth borehole and expanded in its diameter in order to seal the leak. The closure body, at least a part thereof, is moved beyond the lower end of the borehole to enter into the raw material filled cavity, and is expanded within the cavity below the borehole and, with an axially sealing surface, is urged from below against the cavity's sealing surrounding the borehole. With regard to the device, to achieve this, the expandable part has an expandable portion with an axially sealing surface which, once expanded, has a diameter significantly greater than the diameter of the borehole. In order to permit the sealing part being pushed against the borehole wall once it has been expanded inside the cavity, a reversible feed motion or advancing drive is provided.

Abstract: A lens mount for eyeglasses lenses is provided with at least one bite means as an engagement means to permit locating the lenses relative to the lens mount and thus relative to a temple and/or bridge engaging in turn the lens mount. The bite means positively engage the surface of the lenses such that any twisting of the lenses relative to the lens mount is prevented. In a preferred embodiment the lens mount is configured as a bolt/nut design, the bite means being configured as protuberances on the underside of a bolt head opposing the lens.