Patent Application
20060144007
1. Technical Field
The present invention relates generally to construction materials and methods. More particularly, this invention relates to coil anchors for use for lifting and positioning structural materials such as concrete barriers and other heavy and/or cumbersome devices. This invention further relates to a method for manufacturing such a coil anchor.
2. Prior Art
Concrete structures, such as prefabricated barriers or panels, are ubiquitous in the construction industry. As these structures are very heavy, they often must be transported, lifted and positioned through the use of heavy equipment such as a crane. In order to facilitate the transporting, lifting and positioning of such structures, lifting assists and anchors, such as coil anchors, are installed in the concrete structures so as to provide a means to grasp and lift such structures. Typically, the anchors and other lifting assists are embedded into such structures and lifting attachments, such as lifting loops or lifting members, are attached to the anchor or other lifting assist. Often, the anchors and other lifting assists must be positioned within such structures the lifting attachment may be installed onto the anchor after the structure or panel has been formed or cut to the proper length or size.
The lifting attachments, once attached to the anchor or other lifting assist, are used to lift and position the structure into place. In many instances, the lifting attachments often are releasably attached to the structure and often removed once the structure has been position as desired on site. More particularly, the lifting attachments, such as lifting rings and bolts, are installed and removed at the building site, and therefore preferably are designed to be easily and rapidly installed and removed in order to save the maximum amount of time. Not surprisingly, the prior discloses devices placed within concrete structures that allow for the attachment of lifting attachments.
U.S. Pat. No. 4,655,015 to Hoyer discloses an anchor tie device for the construction industry that is in common use. The Hoyer '015 device is an anchor tie for use in carrying prefabricated concrete components and has a threaded part for connecting the tie member to a lifting device and a tie rod member that is secured within the prefabricated concrete component. The tie rod has two end portions such that the first end is secured to the threaded part and the second end is shaped so as to form at least one undulation. The threaded part and the tie rod are secured together by means of radial pressure swaging.
Although the Hoyer '951 device is suitable for many applications, the use of a swaging attachment technique has drawbacks. The two piece structure defines a relatively weak point in the anchor tie, particularly at the junction between the threaded part and the tie rod part. Often the weak point will be the first break or separate during movement and transport of the structure.
Further, current coil anchors in the US comprise a coiled wire with a welded strut. Such a coil anchor is shown in
Accordingly, there is always need for an improved anchor for use in the construction industry. For example, there is a need for an improved anchor having fewer or no weak points, or with weak points that are relatively strong compared to prior art devices, and with a stronger means for securing a lifting attachment within the anchor. Such an improved anchor should have a relatively simple structure and be relatively inexpensive to manufacture. Further, such an improved anchor should be able to be embedded securely into concrete and other heavy or cumbersome structures such that the anchor may resist forces applied to the anchor during lifting and positioning. It is to these needs, among others, that the present invention is directed.
Briefly, the present invention is a coil bar anchor that is embedded into concrete and masonry structures, and the like, such as concrete panels and barriers to assist in the transporting, lifting and positioning of such structures. For the purposes of this disclosure, all such structures will be referred to as concrete structures no matter what their material of manufacture. The coil bar anchor comprises a coil thread segment and an anchor segment (sometimes referred to as a tie rod or tie bar), which are formed as a unitary structure out of a single piece of material. The anchor segment comprises a shaped length of material and is secured within or to the concrete structure to secure the coil bar anchor to the concrete structure. The threaded segment comprises an interior coil thread accessible through an open top side. A lifting attachment is screwed into the threaded segment so that a crane or other lifting mechanism can lift, transport and/or position the concrete structure.
The coil bar anchor is preferably manufactured from a high strength material such as iron or steel. The coil thread segment is comprised of a spiral coil of material and the anchor segment is comprised of a rod of material that can be bent afterward to create a desired shape, if desired. Overall, the unitary coil anchor of the present invention has an overall stronger structure than that of the two-piece anchors seen in the prior art, utilizes a coil thread for added strength over conventional bolt threads, and can have a multi-dimensional anchor segment design for added strength in being retained within the concrete structure.
More particularly, unlike the prior art, because the present invention is formed from a single piece of material, the junction between the threaded segment and the anchor segment is not a weak point relative to the entire coil bar anchor. That is, because the coil bar anchor is formed as a unitary generally uniform uninterrupted structure, the junction between the threaded segment and the anchor segment is stronger than junction between the two separate sections of the prior art. In fact, it has been found that manufacturing the coil bar anchor from a single piece of material results in a stronger coil anchor than manufacturing a coil anchor from two or more separate pieces.
In use and application, the coil bar anchor may be embedded or cast into a concrete structure. In one embodiment, the coil bar anchor is placed into the wet material (that is, the uncured concrete or other masonry material, or other suitable materials such as epoxies, carbon fiber materials, graphite fiber materials, ceramics, and the like) such that a cast forms around at least the anchor segment and preferably also the threaded segment with the top side of the threaded segment accessible afterward. In another embodiment, a hole or slot is drilled into the concrete structure, a construction epoxy is filled therein, and coil bar anchor is inserted into the hole such that top side is accessible afterward. In another embodiment, the coil bar anchor is positioned within a mold of a concrete structure and the concrete material is poured into the mold such that the mold is filled and the wet material forms a cast around the anchor shafts. After the material has set and cured, the coil bar anchor is secured within the concrete structure.
Another aspect of the invention is a method for manufacturing the coil bar anchor. Rather than swaging a coil threaded segment to a separate anchor segment as in the current art, the present invention is formed from a single piece of material. A coil thread can be formed into one end of a rod having a suitable constant diameter, with the other end of the rod acting as the anchor segment. Alternatively, a rod having a larger diameter at one end can be used, with the coil thread being formed into the end of the rod having the larger diameter. Alternatively, a coil bar anchor can be cast using a suitably shaped multi-piece mold.
These features, and other features and advantages of the present invention, will become more apparent to those of ordinary skill in the relevant art when the following detailed description of the preferred embodiments is read in conjunction with the appended drawings in which like reference numerals represent like components throughout the several views.
Illustrative embodiments of the present invention include a coil bar anchor to be embedded into concrete structures and structures of other materials, such as but not limited to concrete and cement barriers, concrete and cement panels, and prefabricated panels and barriers. The coil bar anchor of the present invention is useful particularly with concrete structures that are lifted or positioned using mechanical means. While the invention is described herein in conjunction with the preferred and illustrative embodiments, it will be understood that the invention is not limited to these embodiments.
Referring now to the figures in general, the figures illustrate preferred embodiments of the invention in the best mode known to the inventor at this time. Specifically,
Referring now to
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The shape of the anchor segment 30 may be formed using a cold forming process, a casting process, or any other material forming process suitable for the material of manufacture of the coil bar anchor 10. Such a process is applied to produce a short arc or other disruption in the straight portion of the anchor segment 30. More particularly, after a preliminary structure consisting essentially of the threaded segment 20 and the anchor segment 30 has been formed as a single unitary structure, the arc shape 32 or any other desired disruption may be introduced into the structure of the anchor segment 30. This arc shape 32 or other disruption serves to help retain the coil bar anchor 10 within the concrete structure 100 better generally with higher strength than with a straight anchor segment 30. Thus, arc shape 32 can be any two-dimensional or three-dimensional disruption of the linear shape of anchor segment 30.
Preferably, the coil bar anchor 10 is manufactured from a single, generally linear, piece of material, with the threaded segment 20 and the anchor segment 30 being formed on opposite ends. In one embodiment, the anchor segment 30 may be formed initially as straight rod and subsequently manipulated to a desired arc, wave, helix or other form. It has been found that manufacturing the coil bar anchor 10 from a single piece of material results in a stronger device than manufacturing a coil anchor from two or more separate pieces.
The anchor segment 30 assists in anchoring the coil bar anchor 10 within a concrete or other material structure, such as concrete structure 100, and typically has a length (measured axially) up to approximately 25 inches or longer depending on the load of the concrete structure, and preferably between 6 inches and 25 inches. The anchor segment 30 typically has a diameter or thickness of up to 1.25 inches, and preferably between 0.25 inch and 1.25 inches. Preferably, the threaded segment 20 has a length of up to 6 inches, and more preferably between 1 inches and 4 inches, and more preferably between 11 inch and 3 inches, with a diameter of between 0.75 inch and 3 inches, and more preferably between 0.75 inch and 2 inches. The length of the threaded segment should be on the order of twice the diameter or more of the threaded segment. Preferably, the anchor segment 30 has a straightened length of up to 25 inches, and is approximately straight for up to approximately 2 to 6 inches extending from the threaded segment 20 and curved for approximately 3 to 6 additional inches. The length, diameter or thickness, and curvature design of the anchor segment 30 can be selected based on the application and one of ordinary skill in the art can select the length, diameter or thickness, and curvature design of anchor segment 30 without undue experimentation.
Referring now to
In a preferred application, the coil bar anchor 10 is embedded into a concrete structure 100. In one embodiment, both the threaded segment 20 and the anchor segment 30 are embedded in the concrete structure 100 by casting concrete structure 100 around the anchor bar coil 10 leaving the open top end of the threaded segment exposed so as to be able to receive a lifting attachment. Preferably, the concrete structure 100 is molded such that the threaded segment 20 and the anchor segment 30 are immobilized in the concrete structure 100. For example, the concrete material may be poured into a mold or frame so that the concrete material flows around threaded segment 20 and the anchor segment 30 such that the top edge 21 of the threaded segment 20 is flush with the surface of the concrete structure 100.
In this arrangement, the lifting attachment 40 may be attached to the threaded segment 20. As shown in
Referring now to
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Another aspect of the invention is a method for manufacturing the coil bar anchor 10. The coil bar anchor 10 may be manufactured from a suitable metal or other material. For example, the coil bar anchor 10 may be machined, molded or cast from an iron or steel bar stock. The quality of steel suitable with the coil bar anchor 10 may be selected according to the load bearing forces upon the coil bar anchor 10. One of ordinary skill in the art may select a suitable material without undue experimentation. Rather than swaging a coil threaded segment 30 to a separate anchor segment 20 as in the current art, the present invention is formed from a single piece of material. A coil thread can 22 be formed into one end of a rod having a suitable constant diameter, with the other end of the rod acting as the anchor segment 30. Alternatively, a rod having a larger diameter at one end can be used, with the coil thread 22 being formed into the end of the rod having the larger diameter. Alternatively, a coil bar anchor 10 can be cast using a suitably shaped multi-piece mold.
The dimensions of the coil bar anchor 10 may be dependent on the designed load requirements of a particular application. However, the dimensions may depend on factors such as size of the mechanical lifting device, the size, weight and composition of the concrete structure 100, and the material selected for the coil bar anchor 10. One of ordinary skill in the art may select appropriate dimensions for the coil bar anchor 10 and components thereof.
In one embodiment, the internal threads 22 number at least eight turns; however, a greater or lesser number of internal threads 22 may be necessary to support larger concrete structures 100. It is contemplated that between four and twelve turns should be sufficient for the majority of applications. It is necessary that the coil interior be free of concrete and has a sufficient number of turns to engage the threads 52 of the lifting attachment 40 stem 50
As disclosed previously, in use and application, the coil bar anchor 10 preferably is embedded or cast into a concrete structure 100. The coil bar anchor 10 may be used with or embedded in any concrete structure 100. For example, such concrete structures 100 may include prefabricated panels or barriers and concrete blocks. Further, the coil bar anchor 10 may be used with or embedded in prefabricated walls and construction panels. Concrete structures 100 suitable with this invention are obvious to those with ordinary skill in the art.
In one embodiment, the coil bar anchor 10 is placed into the wet material (that is, the uncured concrete or other masonry material, or other suitable materials such as epoxies, carbon fiber materials, graphite fiber materials, ceramics, and the like) such that a cast forms around the walls of the threaded segment 20 and the anchor segment 30. In another embodiment, a hole or slot 104 is drilled into the concrete structure 100 (as mentioned previously, for ease of understanding, all structures for which the coil bar anchor 10 can be used will be referred to as a concrete structure 100 irrespective of the actual material of manufacture), a construction epoxy 101 is filled therein, and the coil bar anchor 10 is then inserted therein such that top side 21 of the threaded segment 20 is accessible. In another embodiment, the coil bar anchor 10 is positioned within a mold of a concrete structure 100 and the concrete material is poured into the mold such that the mold is filled and the wet material forms a cast around coil bar anchor 10 such that the top side 21 of the threaded segment 20 is accessible. After the material has set and cured, the coil bar anchor 10 is secured in place within the concrete structure 100.
One advantage of the coil bar anchor 10 is that the junction between threaded segment 20 and the anchor segment 30 is stronger than that of the coil anchors of the prior art. As coil bar anchor 10 is formed as a single structure, the junction between the threaded segment 20 and the anchor segment 30 is substantially stronger than that of prior inventions.
While the coil bar anchor 10 is disclosed in connection with the lifting attachment 40, it is understood that the coil bar anchor 10 may used with any fixture or object that may be connected the threaded segment 20. For example, the coil bar anchor 10 could be used with bolts or other construction members. Such fixtures or objects that may be used with coil bar anchor 10 are readily known to those with ordinary skill in the art.
The above detailed description of the preferred embodiments, examples, and the appended figures are for illustrative purposes only and are not intended to limit the scope and spirit of the invention, and its equivalents, as defined by the appended claims. One skilled in the art will recognize that many variations can be made to the invention disclosed in this specification without departing from the scope and spirit of the invention.
