Abstract: The invention relates to a horizontal directional drilling system, comprising a dual string (1), said dual string (1) comprising an inner string (2), and an outer string (3), said inner string (2) is rotatable independently of said outer string (3), a first rotary drive system (4) to drive said inner string (2), a second rotary drive system (5) to drive said outer string (3), a frame (11) to movably support said rotary drive systems (4, 5), a front casing (7) fitted to a distal end of said outer string (3), a drive shaft (8) coaxially positioned into said front casing (7) and connected with said inner string (2) and a hammer (9) connected to said front casing (7) and operable in response to rotation of said drive shaft (8), said hammer (9) comprising a drill head (90) and a drill bit (91) wherein said drill head (90) generating percussive energy using pressurized fluid, e.g. pressurized air, supplied through an annular passage between said outer string (3) and said inner string (2).

Abstract: A bottle cap is disclosed having a pair of spaced score lines extending across the top of the cap and across a peripheral depending skirt to the edge. A sealing element is bonded to the surface of the inside of the cap. The bonded interface between the sealing element and the cap extends across portions of each of the score lines away from a downwardly depending tear-off flap. The bonded interface serves to prevent tearing of the score lines when the cap is removed. The sealing element is undamaged when the cap is removed so that the cap may be reused.