Abstract: A suction head for a suction device including an annular support member (1), an annular guide member (2) releasably connectable with the support member (1), a suction nipple (51) connected with the support member (1), and an annular seal (6) projecting beyond a first free end of the support member (1) in an axial direction, with the guide member having a first end region (22) projecting beyond the first free end of the support member (1) in the axial direction by a length which at most corresponds to a length by which the seal projects beyond the first free end of the support member (1).

Abstract: In drilling a bore in a structural component (3) using a hollow cylindrical core drill bit (4) initially a guide such as a disk (1) or a template (12) is secured to the surface of a structural component (3) for guiding one of the inner or outer circumferential periphery of the core drill bit. At the commencement of the drilling operation, the core drill bit (4) is guided by the disk or template and maintains the bit in a centered position. The guide can be fixed to the surface of the structural component (3) in a known manner, such as by an adhesive or by fastening elements (2, 6) driven directly into the structural component. Generally core drill bits of smaller diameter can be guided by the outer circumferential periphery of the guide (2) or by the inside circumferential periphery of the template (12).

Abstract: A working tool holder for a drilling or chiseling device includes a holder sleeve with an axially extending conically shaped section within a holder opening or bore. A working tool to be secured in the holder sleeve, has a tool shaft with a conically shaped section to engage the conically shaped section in the holder opening. Grooves are formed in the tool shaft to receive inwardly projecting ridges in the holder opening. The tool shaft has recesses to receive the pins mounted in the holder sleeve. The tool shaft and an actuating sleeve extending around the holder sleeve each have connecting threads for securing the working tool in the holder.

Abstract: A tool holder for drilling and chiselling tools includes a receiving sleeve forming a bore with a conically shaped section for receiving a conically shaped shank on a drilling or chiselling tool. Shoulders extending in the axial direction of the sleeve are formed on the surface of the conically shaped section for interengagement with grooves in the drilling or chiselling tool shank so that the sleeve can rotate the tool. Locking elements in the form of axially elongated pins are mounted in the receiving sleeve so that the pins extend transversely of the sleeve axis and tangentially of the conically shaped bore section. The pins are spring biased toward the bore section and are displaceable generally radially relative to the bore. The pins are arranged to seat within an annular groove in the shank of the tool.

Abstract: A self-drilling dowel is formed by a tubular member defining an axially extending bore. The tubular member has a leading end and a trailing end with a cutting head at the leading end. A spreader member is insertable into the bore for expanding the tubular member. A member, preferably a plate, is positioned within and extends transversely across the bore adjacent the leading end forming a closure. The bore closure member is spaced axially from the leading end and it is separate from the tubular member and is displaceably fitted within the bore.

Abstract: A self-drilling dowel assembly is made up of an expansion sleeve with an annular drill bit formed on one end and a spreader axially displaceable through the sleeve after it has formed a borehole for expanding and anchoring the sleeve in the borehole. The bore through the sleeve is divided by a transverse partition wall into two axially extending blind bores each extending inwardly from an opposite end of the sleeve. The blind bore extending from the drill bit end of the sleeve has a diameter which is 0.5 to 0.9 times the exterior diameter of the sleeve and the axial length of this blind bore is also about 0.5 to 0.9 times the exterior diameter of the sleeve. Axially extending grooves are formed in the exterior surface of the sleeve and recesses extend inwardly from the base of the grooves for facilitating the expansion of the sleeve.

Abstract: A self-drilling dowel has a drill head extending across its leading end. A bore extending through the dowel from its trailing end is closed at its leading end by the drill head forming a centrally located blind bore. The blind bore is cylindrically shaped for a part of its axial length from the trailing end of the dowel with the remainder of its axial length to its closed end tapering inwardly from the surface of the cylindrically shaped part. A spreader is positionable in the central bore with complementary dimensioned surfaces relative to the cylindrically shaped and tapering parts of the bore. Slots are formed in the dowel and extend from the drill head to approximately the transition plane between the cylindrically shaped and tapering parts of the blind bore. The slots have a dimension extending transversely of the axis of the bore just sufficient to open into the bore at the transition plane.

Abstract: An impact dowel for insertion into a prepared bore hole in receiving material consists of an axially extending expansion sleeve and a spreading element insertable into the bore in the sleeve. The expansion sleeve and spreading element each have a first end and an oppositely directed second end with the first end being inserted first into the bore hole. The bore in the expanding sleeve has a pair of axially spaced restrictions which limit the axial displacement of the spreading element through the bore. The second end of the sleeve has an outwardly directed shoulder and a connecting section adjacent to the shoulder. The connecting section absorbs substantially only tensile forces.