US2524480A - Bolt anchorage - Google Patents

Description

T. c. scHENK 2,524,480

Bour ANcHoRAGE Oct. 3, 1950 Filed Nov. 20l 1948 lNVENTOR Patented ct. 3, 1950 jUNITED S1`A"II 3Sv PATENT OFF-ICE' i t 2,524,480 j" y "l BOLT ANCHORAGE Tamis C. Schenk, Richmond Hill, N. Y.

Application November 20, 1948, Serial No. 61,249

1 Claim (Cl. 85-32) This invention relates to anchorages for bolts and other threaded elements in concrete or similar plastic masses. An object of the invention is to provide a device of this character which will threadably receive the bolt and hold it rmly in place under hard conditions of service.

I am aware that prior to the present invention, eiiorts have been made to embed in concrete masses, threaded spirals or helicals for the reception of the threaded end portions of bolts or like elements, and the primary object of the present invention is to provide a threaded anchorage of such a character which will be, because of its improved design and construction more firmly anchored in the concrete mass so that its dislodgment will be virtually impossible without destruction of the surrounding portions of the concrete in which it is embedded.

The invention further contemplates the provision of an article of this character which can be speedily and economically made in quantity; which can be readily placed in position, and after the concrete has hardened or set, will act as a rm and secure anchorage for the bolt.

These and other objects are attained by the invention, a more particular description f which will be hereinafter set forth and pointed out in the claim appended hereto.

In the accompanying drawing, wherein an illustrative embodiment of the invention is disclosed, Fig. 1 is a vertical sectional View through a part of a concrete mass showing the anchorage embedded therein and in engagement with the threaded portion of a bolt or similar threaded member; Fig. 2 is an end view of the helical anchorage; Fig. 3 is a side elevation of the same, and Fig. 4 is a face View of the metallic strip from which the coil or helix is formed.

Referring to the embodiment of the invention illustrated in the drawing, the anchorage is preferably formed from an elongated strip I of flat sheet metal of the form generally shown in Fig. 4. The length of the strip from which the coillike anchorage is produced is, of course, dependent upon the desired length of the anchorage. In the form shown, the strip is provided with one longitudinal straight edge 2, the opposite edge 3 being undulated or formed with decidedly flat, spaced serrations. The strip formed as above described is Wound or shaped into helical or spiral form, as clearly shown in Fig. 3. The helix or spiral so produced has its inside diameter or inner edge composed of the straight edge 2 of the strip I and hence the inside diameter of the coil 2 or helix, or the bore thereof, will be of uniform or constant diameter.

The diameter of the coil thus formed will, of course, be that intended to permit of threadable engagement with the threaded portion 5 at the end of a bolt 6 or other threaded element, and the length of the coil will be that required to accommodate the threaded portion of the bolt. At one end, the end convolution of the coil is inwardly bent or distorted as shown at 'l to form a limiting abutment for the pointed end of the bolt 6.

:It will be noted that the undulated edge 3 of the strip I is that which forms the outer edge of the formed coil or helix, and as a result, the outside diameter of the coil or helix is varied. That is to say, the shape of the coil is that of a plurality of frusto-conical members connected endwisely. It will be also noted that the convolutions of the helix or coil are spaced apart, acy cording to the threads to be accommodated, and that concrete in which the coil is embedded can enter between these convolutions and rest against the flat faces 9 thereof.

When an anchorage coil of this character is embedded in a concrete mass, the concrete will flow around the same and enter between the convolutions of the coil as well as around the undulating surfaces dened by the outer edge of the coil.

The arrangement described is such that it is impossible to withdraw the coil out of the concrete by axial movementpf the coil as well as extremely diicult, if not impossible, to rotate the coil in the concrete mass. The conical disposition of the coils of the helix tends to furnish a positive bearing on a larger area of con- -crete and insures a better lling of the voids between the turns in the narrow parts of the coil.

While I have herein described the strip from which the coil is made as being fabricated from at metal, it is apparent that it might be other- Wise formed, as for example, from wire made possibly triangulated in cross-sectional shape and having one edge undulated as described with respect to the embodiment shown in the drawing.

While I have herein described one embodiment o f the invention, it is obvious that the same is not to be restricted thereto but is broad enough to cover all structures coming within the scope of the annexed claim.

What I claim is:

An anchorage for insertion in concrete or material of like character comprising, a iiat metal strip having a straight lengitedinal aise and e 3 longitudinal edge of undulated form, said strip REFERENCES CITED being coiled into a spiral having spaced-apart The following references are of record in the convolutions, the outside diameter of the coiled me of this patent:

strip being gradually increased or decreased in diameter according to the undulations of said 5 UNITED STATES PATENTS outside edge, the straight edge of the strip form- Number Name Date ing the inside edge of the spiral and providing a 163,485 Hansen May 18, 1875 constant and uniform inside diameter for said 240,780 Smith Apr. 26, 1881 spiral and adapted to form a spiral thread fOr a 271,929 Seybert Feb. 6, 1883 threadedrmember; inserted within the coil. f 10v 1,230,603 Richmond` June 19, 1917 1,311,646 Gordon June 29, 1919 TAMIS C. SCHENK.A I 2,439,685 Findley Apr. 13, 1948

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