摘要:
The drill tool for drilling a drilled hole with an undercut in a wall has a drill tool shaft having a drill head at a free end of the drill tool shaft, a depth insertion stop formed on the drill tool shaft to limit an insertion depth of the drill tool in the drilled hole and cutting elements projecting laterally from the drill head for making the undercut. The drill tool shaft (15) has an enlarged portion (10) acting as a pivot bearing for making the undercut spaced approximately equally from the insertion depth stop (4) and the drill head (6). To prevent sticking of the drill tool in the drilled hole the drill tool shaft (15) also has a cylindrical step portion (11) connected to the enlarged portion (10) and located between the enlarged portion (10) and the insertion depth stop (4). A discontinuous transition between the enlarged portion (10) and the cylindrical step portion (11) forms a scraping edge (12) and the cylindrical step portion (11) has a diameter less than a diameter of the enlarged portion (10). Another cylindrical step portion (14) with another scraping edge can also be provided.
摘要:
The expansible anchor consists of a shank having a threaded portion for fixing an article at its rear end and a reduced cross-sectioned portion with an adjoining expander cone at its front end, and, positioned over the reduced cross-sectioned portion, an expansible sleeve having longitudinal slits forming expansible segments and locking elements protruding beyond the diameter of the expansible sleeve and arranged on the expansible segments. To increase the holding force of the anchor and to allow the expander cone to slide-up and the expansible sleeve to expand in operation if the drilled hole become enlarged as a result of cracks forming, the locking elements consist of several interconnected punched elements on each expansible segment extending in a longitudinal direction of the expansible segments. Each punched element is triangular with a point directed towards the front end of the expansible segments. An improved method of making the expansible anchor which includes stamping a blank for the expansible sleeve somewhat undersized from sheet metal, subsequently pressing it and then punching the punched elements in the expansible sleeve is also described.
摘要:
A drilling device for producing drilled holes with an undercut has a drill bit having a drilling head, a depth stop, an enlargement provided between the the drilling head and the depth stop and acting as a swivel bearing, a suction bell rotatably mounted on the depth stop, a bearing washer, and a resilient, ring-shaped cushioning element provided on the depth stop. The cushioning element abuts against the bearing washer and is connected to the suction bell. The depth stop of the drill shank has a concavely curved end face and the bearing washer has a convexly curved sliding face which rests on the concavely curved end face of the depth stop.
摘要:
A plug assembly that comprises a bolt having a cone portion at one end thereof and an external thread at another end thereof, a sleeve for mounting over the bolt and having an expansible portion at an end thereof which is adjacent to the one end of the bolt, and a tubular member screwed over the bolt until its engagement with an end of the sleeve which is remote from the expansible region for securing the plug assembly against rotation.
摘要:
The anchoring rod for anchoring an article to a base using a compounded mass including a synthetic resin, has a threaded portion at its rear end for fixing the article; a threaded nut engagable on the threaded portion for applying a mounting torque; a head having a shoulder facing toward the rear end, an outer surface tapering towards the front end of the anchoring rod and having a wedge-like tip at the front end; a conical portion connecting the head and the threaded portion and tapering toward the head; and a resilient annular washer bearing on the shoulder of the head.