| 摘要 |
FIELD: mechanical engineering; fasteners. ^ SUBSTANCE: proposed expansion bolt has expanding sleeve and expanding screw to expand the sleeve. Expanding screw has saw-like thread whose more steep and short side is located in direction of turning-in of expanding screw in front, and more flat and long side, in rear. Thread has inner diameter increasing from front to rear, being in meashing with expanding sleeve which is made of plastic. Rear side of thread in direction of turning-in has angle alpha to axial direction of expanding screw decreasing approximately from 28o at front end of thread to approximately 7o at rear end of thread. ^ EFFECT: provision of high anchoring force. ^ 7 cl, 9 dwg |
