Hilti Aktiengesellschaft

Hubert Forster

Armin Herb

Michael Werner

Thomas Doppelbauer

Franz-Xaver Huber

Herbert Kaufmann

Frank Ansch&uuml;tz

Helmut Fuchs

Frank Anschutz

A dowel bolt is formed of a bolt ( ) and has at the trailing end an outer thread ( ) and on the leading end an expansion head ( ) expanding in the setting direction (S) and an expansion sleeve ( ) that can be expanded by the expansion head ( ). At the trailing end face ( ) directed away from the setting direction of the bolt, the bolt has at least one peripheral recess ( ) with a depth (t ) providing a setting control and that can be economically manufactured.

Dowel bolt with expansion control

A fastener is formed of an axially extending shaft ( ) and a driving head on the end directed away from the setting direction, and has on its underside or first side ( ) for the prevention of unintended loosening, a plurality of webs ( ) extending radially from the longitudinal axis (L) of the shaft up to the external periphery ( ) of the underside ( ). The webs ( ) having a substantially trapezoidal cross-section, are limited by a face surface ( ) on the underside ( ), extending between two flank surfaces.

Fastener driving head

An attachment assembly formed of an anchor bolt (1) and an expansion wedge (2) with the anchor bolt having an outside surface (4) at its leading end in the setting direction and widening in a wedge-like manner. The expansion wedge (2) can be displaced axially along the wedge-like outside surface (4) for effecting expansion of the attachment assembly. At its trailing end (6), the anchor bolt (1) has a flange-like engagement part (5) for applying a load to a receiving material into which the attachment assembly is expanded. The engagement part (5) has a throughbore (3) through which the expansion wedge (2) extends and is secured in a preassembled state. The expansion wedge (2) has a trailing end section (14) extending rearwardly from the engagement part (5) in the preassembled state so that in the expanded state the expansion wedge is held in a press fit in the throughbore (3).

Attachment assembly with anchor bolt and expansion wedge

The expansion dowel includes an expansion sleeve (1) and an expanding member (5). The expansion sleeve 1 is provided with a bore (2) tapering in the setting direction as well as with open ended longitudinal slots (3). The expanding member (5) has a blind bore (6) open towards the setting side and has a lug (7) projecting from same at its opposite end, wherein the cross-sections of lug (7) and blind bore (6) are matched in such a way to one another, that a rated break point or failure point is formed. The force dependent response of this rated break point leads to a force dependent expansion while maintaining the driving or advance travel (X).

Expansion dowel with sleeve and expansion member

A self-tapping screw has a cutting thread formed by two separate threads (3, 4). An imaginary envelope (5) defines a annular space (5) laterally enclosing the screw shank and has a section (5a) tapering inwardly along an inwardly tapering leading end section (1a) of the shank (1). The inwardly tapering section of the annular enclosing space an envelope forms an angle (B) considerably larger than the angle (A) formed by the tapering leading end section (1a) of the shank. The leading ends (3a, 4a) of the separate threads (3, 4) are located diametrically opposite one another for uniform distribution of the forces developed when the screw penetrates into a hard receiving material, such as concrete, masonry, gas concrete and the like.

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Moorenweis, Germany

Hubert Forster