Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Having separate expander means – With hole forming means
Patent
1983-02-22
1985-05-21
Holko, Thomas J.
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Having separate expander means
With hole forming means
411 77, 411 82, 405261, F16B 1308
Patent
active
045182906
DESCRIPTION:
BRIEF SUMMARY
The invention concerns an anchoring bolt with a connection portion, a smooth rod section and an insertion portion, by which it is possible to produce conical undercutting in a cylindrical pre-bore which is filled with a mortar capsule, when the anchoring bolt is drilled into the bore.
BACKGROUND AND PRIOR ART
An anchoring bolt of that kind is described in DE-OS No. 29 41 769. The conical undercutting is produced in the case of the known anchoring bolt by the cooperation of rod profiling and the presence of abrasive grains in the mortar capsule. The anchoring bolt executes a staggering motion in which the insertion end, with its profiling, is moved in a more or less defined path. The abrasive grains of the mortar capsule, in the case of the known anchoring bolt, are pulled along intermittently with a component of motion in the circumferential direction during the drilling-in movement and, as a result of their being alongside the insertion portion, they are forced along the walls of the cylindrical pre-bore. The exact shape of the undercutting results as a matter of chance and it is not excluded that a cross-section through the undercutting is oval instead of round.
If the known anchoring bolt should be used for anchoring in a so-called parting zone, a defined undercutting is desirable. In particular it is advantageous of the undercut has circular symmetry, since it cannot be foreseen in which direction the cracks that may possibly appear will run.
SUMMARY OF THE INVENTION
Starting from the above-described state of the art, the invention has the object of providing an anchoring bolt of the kind mentioned in the introduction by which it is possible to provide a defined and reproducible widening without the introduction of abrasive grains.
This object is accomplished according to the invention by having the anchoring bolt provided, in the region of the insertion portion, with a slot, running axially from the insertion end, into which there projects the narrowed-down end stem of an axially shiftable spreading wedge. In the setting operation the wedge first breaks the resin mortar capsule located in the bore hole and then finally reaches the bottom of the bore. Under hammer-driling movement and continuous axial pressure, the insertion end is then pushed over the wedge standing up in the bore. The insertion portion of the anchoring bolt is hereby pressed against the bore walls and widened. The wedge is driven into the slot until its stem abuts the closed slot end. When this point is reached, the anchor rod has reached its greatest possible spreading and the intended undercut is produced.
The removal of the bore material is performed either by profiling formed on the insertion portion of the rod or by inserts provided in the insertion portion which are disposed radially protruding beyond its circumference.
It is useful for the wedge to have an extension in the form of a stem with parallel running surfaces, so that the wedge can be clamped in the slot and the user receives the anchor bolt and the wedge as a set. It is advantageous for the slot to extend through the profiling all the way into the smooth shaft section and for the width of the wedge to be somewhat smaller than the outer diameter of the profiling. The optimum size of the wedge angle for the wedge depends upon the hardness of the fastening ground, the material quality of the anchoring bolt and the length of the wedge. A favorable wedge angle for a fastening ground of concrete lies in the region from 2.degree. to 6.degree.. Good crushing of the mortar capsule and mixing up of the synthetic resin mortar is obtained when the wedge has an obtuse point at its outward end and the anchoring bolt is provided at its end surface with mixing teeth.
In one example of embodiment of the invention the inserts are constituted as round hard metal pegs, which are soldered, cemented or pressed into radially extending socket bores. In order to prevent pulling the insertion portion of the anchoring bolt, once it becomes fixed in the bore, away from the wedge, it is ad
REFERENCES:
patent: 948938 (1910-02-01), Skidmore
patent: 1762349 (1930-06-01), Phillips
patent: 2570618 (1951-10-01), Werner
patent: 3202035 (1965-08-01), Rosselet
patent: 4073212 (1978-02-01), Lerich
patent: 4091882 (1978-05-01), Hashimoto
patent: 4162133 (1979-07-01), Clark et al.
Frichmann Albert
Kistner Herbert
Mermi Kurt
Sternisa Danilo
Holko Thomas J.
Upat GmbH & Co.
Wilson Neill
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