| 摘要 |
A fracturing device which is intended, by insertion into a bore in a material and expansion therein, to fracture or crack the material, comprises two end pieces (4, 5) which are disposed at the opposing ends of the fracturing device and are interconnected via a longitudinally directed drawbar (1). An elastic expander sleeve (8) surrounds the drawbar (1) and seals against the end pieces (4, 5), and may be subjected to inner excess pressure. In order to avoid rupture at the anchorage of the expander sleeve (8) in the end pieces (4, 5), the expander sleeve (8) is provided with a radially expanding, thick-walled central portion (23). At each end thereof, there is disposed interiorly in each end piece (4, 5), an axially extendible thin-walled strain portion (26). The expander sleeve (8) has, at its opposite ends outside the strain portions (26), thick, bead-shaped end portions (38) which are accommodated in corresponding interior, annular grooves (12) in the end pieces (4, 5). |
