Hilti Aktiengesellschaft

Arndt Bergner

Armin Herb

Erich Leibhard

Gusztav Lang

A device, for cutting an undercut in a borehole at a location spaced from the surface of a material into which the borehole is formed, includes a housing (1) with a bore therethrough and a guide sleeve (2) rotatably supported in the housing bore and having an eccentric bore therein. A bushing (3) with an eccentric bore is rotatably supported in the guide sleeve bore. A drive shaft (7) is rotatably supported in and extends through the eccentric bore of the housing and has a cutter head (9) at one end. The drive shaft (7) can be shifted from a centered position within the housing bore into an eccentric position by rotation of the bushing (3) relative to the guide sleeve (2). In the eccentric position, the cutter head (9) can penetrate into and form an undercut in the surface of the borehole. A displacable snap-in element (16) in the housing (1) prevents rotation of the guide sleeve (2). When the maximum eccentricity of the drive shaft (7) is reached, the snap-in element is disengaged from the guide sleeve by an actuating cam (3a) on the bushing (3). Subsequently, the guide sleeve (2) and the bushing (3) can be rotated together through at least 360.degree. degrees for cutting the undercut. A blocking member (13) prevents rotation of the guide sleeve (2) during rotation of the bushing back into the center position.

Device for cutting undercuts

An expansion dowel assembly is made up of an anchor bolt and an expansion sleeve laterally enclosing the bolt. The sleeve is expanded by driving it in the axial direction relative to the bolt so that the end of the sleeve widens as it moves axially over a conically shaped expanding member on the bolt. The axially extending surface of the expanding member is formed as a concave surface affording an increasing conicity in the driving direction. Cutting teeth are formed on the outer surface of the sleeve and provide a saw-tooth section. When the sleeve is driven relative to the bolt, the teeth cut into the surface of a borehole in a receiving material and form an undercut in the borehole surface. To facilitate expansion, an annular groove is located in the outside surface of the sleeve adjacent the cutting teeth. The annular groove is located on the opposite side of the cutting teeth from the leading end of the expansion sleeve.

Expansion dowel assembly

An expansion dowel assembly is made up of an anchor bolt and an expansion sleeve laterally enclosing the bolt. The sleeve is expanded by driving it in the axial direction relative to the bolt so that the leading end of the sleeve widens as it moves axially over a conically shaped expanding member at the leading end of the bolt. Cutting teeth are formed on the outer surface of the sleeve at its leading end and provide a saw-tooth section. The teeth cut into the surface of a borehole in a receiving material and form an undercut in the borehole surface as the sleeve is expanded. To facilitate expansion, an annular groove is located in the inside surface of and adjoining the cutting teeth. The annular groove is spaced on the opposite side of the cutting teeth from the leading end of the expansion sleeve.

A device for dispensing metered quantities of flowable multi-component masses includes a housing with separate chambers, each containing a flexible bag with one component of the multi-component mass. Material is pressed out of the bags by a liquid propellant supplied from a reservoir in the housing to the chambers by gear wheel pumps located in a conduit connecting the reservoir to the chambers. The pumps are connected to a common drive so that the mixture ratio of the components is exactly maintained for any desired amount to be dispensed.

Dispensing device for flowable masses

An expansion anchor assembly for use in a borehole with an annular undercut includes a threaded anchor stud with a head part at its leading end inserted first into the borehole. Locking elements are arranged around the anchor stud at the head part, a conically shaped member is arranged to expand the locking elements in the radial direction, and an annular abutment member is in threaded engagement with the anchor stud and is arranged to axially displace the conically shaped member. By threading the abutment member toward the leading end of the anchor stud, the locking elements are displaced radially outwardly in the annular undercut. The radially outer surface of the abutment member is located within the axial projection of the radial outer surface of the conically shaped member. Accordingly, the abutment member and conically shaped member can be countersunk relative to a part to be secured to the material in which the borehole is formed. The extent of the countersink relative to the part varies according to the location of the annular undercut so that a complete anchoring of the part is ensured in every case.

Expansion anchor assembly

An expansion anchor assembly for use in a bore with an undercut section adjacent the base of the bore, includes an axially elongated expansion sleeve and an anchor bolt positioned within the sleeve with an expansion cone at one end of the bolt. The expansion sleeve is slit from one end for a portion of its axial length. By drawing the expansion cone into the slit end of the sleeve, the sleeve can be expanded. An expansion element is seated within a recess in the outside surface of the sleeve. The base of the recess has a decreasing depth in the direction toward the slit end of the sleeve. The expansion element secures the expansion anchor assembly within the bore.

An expansion dowel assembly is used to anchor a part to the surface of a structural member. The expansion dowel assembly is inserted into and anchored within a borehole in the structural member. The assembly includes a support tube, an anchor rod extending axially through the support tube, and expansion elements positioned within the support tube so as to be radially displaced by the anchor rod into anchoring engagement with the structural member. The expansion elements are positioned within the support tube in bearing contact with a support surface. The support surface contacting the expansion elements faces toward the bottom of the borehole into which the dowel assembly is inserted. The support surface is a web formed as part of the support tube and it is axially displaceable when a force acting on the anchor rod exceeds a predetermined level.

In a dispensing device for filling boreholes with a single or multi-component adhesive, filler, sealer or primer, the material is conveyed from storage containers holding the individual components through a supply pipe and an outlet nozzle which dispenses the material directly into the borehole. By manually operating a handle lever, material is displaced out of the storage container into the supply pipe. Further, an actuating unit operated by the handle lever is connected to the outlet nozzle for telescoping it relative to the supply pipe whereby material is displaced out of the supply pipe through the outlet nozzle into the borehole.

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Munich, Germany

Arndt Bergner