Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B13/00—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose
  • F16B13/02—Dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose in one piece with protrusions or ridges on the shaft

Definitions

• the invention relates to an expansion anchor for anchoring in boreholes of any diameter, consisting of a sleeve lying against the borehole wall, which is provided with longitudinal slots over part of its length.
• expansion anchors Numerous types of expansion anchors are known from everyday practice, which are used to fasten wood screws, threaded screws used in industry and in households in pre-drilled holes. These expansion anchors require a borehole, the diameter of which is three or is four times the screw diameter.
• the expansion effect of the screw to be held begins to occur when the screw has been driven in at least up to half of the expansion anchor.
• the expansion sleeve spread through the front end of the screw only touches the threads in a few points, although this contact makes a significant contribution to determining the holding values.
• the screw does not touch the introduction part of the expansion anchor and the anchor only rests on the borehole wall with its rear expanded part. This fact affects the holding value of the conventional expansion plug in a strong till.
• the depth and also the diameter of the drilled hole is of great importance.
• the expansion plug is rotated by the driven screw, which expands the hole even more and prevents the screw from being driven in.
• the expansion dowel disappears completely in a hole that is too deep, i.e. it is pushed back so far by the screw that only an extremely long screw can work together or a new hole should be drilled that is neither technically nor aesthetically advantageous.
• the expansion anchor should be hammered into the hole, causing the anchor to be broken, bent or crushed, or the insertion part of the anchor protrudes from the hole to such an extent that it strengthens the anchor securing part must be cut off.
• conventional expansion anchors it sometimes happens that the driven screw leaves the dowel in a lateral direction immediately behind the insertion part, so that the sleeve of the dowel, which is slit open in the longitudinal direction, is not expanded, which means that there is no contact force between the expansion sleeve and the borehole wall.
• the holding value of such an expansion plug is zero.
• the longitudinal slots do not extend to the rear end of the anchor and a dog nut is fastened in the rear sleeve end.
• a threaded screw is inserted over the thing to be fastened into the dowel and screwed into the round nut.
• the round nut compresses the dowel in the longitudinal direction, the slotted middle part is pressed against the borehole wall.
• the disadvantage is that the round nut can be ejected from the sleeve or that the dowel material that is too soft cannot hold the round nut in place.
• the invention is therefore an object of the invention to provide a fastener element which, while eliminating the abovementioned shortcomings, ensures uniform contact between the driven screw and the sleeve or between the sleeve and the borehole wall along the entire length of the dowel with different or uneven hole diameters, thereby ensuring a higher holding value with a smaller dowel or hole diameter, the depth of the drilled hole puncturing the Dowels not badly affected.
• the sleeve has a star-shaped through opening and a smooth outer jacket which is cut along a helix along its entire length.
• the solution according to the invention results in a better contact between the sleeve and the borehole wall along the expansion dowel, which enables complete filling of the borehole and thus high holding values.
• the star-shaped through opening provides secure guidance for the screw and a suitable internal thread for the respective screw.
• the drilling depth is of no interest, since the dowel tube, which is expediently produced by extrusion, can be cut to size after insertion into the hole.
• the diameter of the pre-drilled hole can be reduced by almost half when using the expansion anchor according to the invention compared to a conventional anchor.
• ribs made of the material of the expansion anchor are formed on its outer jacket transversely to the longitudinal axis of the anchor over a part of the circumference or over the entire circumference, which increase the holding value of the anchor by an increased frictional force.
• FIG. 2 shows a section through the fastening element from FIG. 1 along the line II-II
• Figure 3 shows the fastener inserted into a borehole with a partially driven wood screw.
• the expansion anchor according to Figure 1 consists of a sleeve 1, which is made of plastic, for example from semi-hard polyethylene by extrusion.
• the expansion anchor can be cut up to a predetermined length or produced as a longer expansion anchor tube with a length of 40-60 cm.
• the outer jacket of the sleeve 1 is cut along its entire length along a helix 2 according to the figure.
• the helical line 2 is also designed to be right-handed for standardized, ie for right-handed screws.
• a pitch angle ⁇ of the helical line 2 can be selected in the range from 5 to 60 ° depending on the dowel diameter. This pitch angle ⁇ , which has an average value of 30, also determines the thread pitch of the helical line 2. According to FIG.
• the sleeve 1 has a star-shaped central through opening 3, which in the embodiment shown has the shape of a hexagram. From the figure it can be seen that the screw line 2 cuts through the relatively thin wall of the sleeve 1 compared to a conventional expansion dowel.
• Figure 3 shows an expansion dowel, which is used for anchoring in a borehole 4 in a masonry 5 and adapted to the depth of the borehole 4 by cutting off the protruding part.
• the expansion anchor is inserted into the borehole 4 in such a way that the one with the right-handed screw benlinde 2 provided and is screwed along the cut sleeve 1 counterclockwise into the hole 4.
• the "threads” move along the helical line 2, as a result of which the diameter of the sleeve 1 is reduced and the sleeve 1 can easily be screwed into the borehole 4.
• the diameter of the borehole 4 or the uniformity of the hole diameter is irrelevant, since the elastic sleeve 1 regains its original shape after being released. In this state, the sleeve 1 is only partially against the wall of the borehole 4.
• the element to be fastened in this case a screw 6, is screwed into the expansion dowel.
• the penetrating threads of the screw 6 attempt to bring along the inner edges of the star-shaped through opening 3 in the direction of rotation due to the resulting frictional force.
• the parts of the sleeve 1 separated along the helix 2, that is to say the “threads” of the sleeve 1 are displaced in one direction, as a result of which the.
• Diameter of the sleeve. 1 increases and the sleeve 1 is pressed over its entire surface against the wall of the borehole 4.
• the screw threads then deform the inner edges of the star-shaped through opening 3 and form an internal thread therein. This ensures that the fully screwed screw 6 is evenly stuck in the sleeve 1 in the entire contact area.
• the retention value of the anchoring depends on the diameter of the screw 6, the borehole 4 and the shape of the inner through opening 3, and experience has shown that it is higher than the retention value of a conventional anchor of the same dimensions.
• ribs can be formed transversely to the longitudinal axis of the material of the dowel that extends on its outer jacket over part of the circumference or over the full circumference, which ribs in certain types of masonry increased frictional force and thus a higher holding value.
• two screw lines 2 can be attached to the sleeve 1 of the expansion anchor like a two-start thread or elastic metals can be used as the raw material of the anchor instead of plastic.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Dowels (AREA)
• Joining Of Building Structures In Genera (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10952559

Family Applications (1)

Country Status (3)

Families Citing this family (2)

Family Cites Families (7)

• 1985
  • 1985-03-06 EP EP19850901538 patent/EP0176545A1/de active Pending
  • 1985-03-06 WO PCT/HU1985/000015 patent/WO1985004221A1/de not_active Application Discontinuation
  • 1985-03-06 JP JP50130685A patent/JPS61501652A/ja active Pending

Non-Patent Citations (1)

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