Construction fastener assembly

Abstract: A construction fastener assembly (10) to be secured with an adhesive (16) within an aperture (12) of a structure (14) such as masonry, concrete or metal where the fastener assembly includes an elongate fastener member (10) having a first end (24) for insertion within the aperture (12) and a second opposite end (26) accessible from the exterior of the aperture (12). An adhesive retaining member (22) is secured to the first end (24) of the fastener member (10) for accepting adhesive (16) therein, for flexibly collapsing upon insertion of the retaining member and the fastener member (10) within the aperture (12) and for ejecting the adhesive (16) from the retaining member (22) into the aperture (12) to secure the fastener member (10) therein.

Description: The present invention relates generally to construction fasteners, and more particularly to a construction anchor or bolt which is adhesively bonded within an aperture defined in a structure formed from masonry, concrete, metal or the like. Construction anchors and bolts typically are adhesively bonded within apertures formed in masonry, concrete and similar structures. Such anchors and bolts frequently are made of metal and are substantially cylindrical in shape, the anchors including a longitudinally threaded bore and the bolts being threaded about their peripheries. After being secured to the surface, other objects can be readily secured to or suspended from the anchors or bolts. An example of an adhesively secured construction anchor is illustrated in US-A-5,263,804. To install that anchor, an aperture is drilled into the masonry surface and then cleaned of debris. A construction adhesive, such as epoxy, then is injected into the aperture from an injection gun. The anchor is inserted within the aperture with a cap positioning the anchor at a desired depth while the adhesive sets to secure the anchor thereto. An important criteria in securing such anchors is providing the proper size aperture and corresponding amount of adhesive within the aperture for the particular size anchor being utilized. If the amount of adhesive is reduced, the anchor may not be properly secured to the structure or air pockets may develop within the mixture. If too much adhesive is utilized, adhesive may squeeze out of the aperture upon insertion of the anchor which is undesirable. In use, to ensure enough adhesive is applied, the aperture frequently is completely filled with adhesive. Upon insertion of the anchor, some 80% of the adhesive is squeezed out and wasted. Adhesive squeeze out is particularly a problem when the anchor is being secured to a ceiling of a structure since the adhesive may fall onto and injure a user. Additionally, when secured to a ceiling, the adhesive may fall out before the anchor is set therein and/or extrude out due to hydraulic pressures created by air pockets. As FIG. 6 illustrates, existing fasteners have attempted to solve such problems by employing a separate, tubular metal screen 100 for use with an anchor 102. At the point of installation of such a fastener, the metal screen 100 is inserted over the interior end of the anchor 102 to a random position and is loosely retained on the anchor 102 by friction. The tubular metal screen 100 then is filled with adhesive which is sufficiently viscous to prevent adhesive from seeping through the mesh of the screen. The metal screen 100 and anchor 102 then are inserted within the aperture, screen first. Upon contacting the bottom of the aperture, the metal screen 100 is forced along the length of the anchor 102 to the position illustrated in FIG. 6. At the same time, the adhesive is expelled from the metal screen 100 and flows about the metal screen 100 and the anchor 102 to secure both the metal screen 100 and anchor 102 within the aperture upon setting. Such a metal screen 100, however, does not enable proper bonding of the anchor 102 directly to the structure. Accordingly, the pull out strength of the anchor 102 is reduced. Additionally, since the metal screen 100 is loosely and movably placed on the anchor 102 at the point of application, the proper amount of adhesive may not be employed. Furthermore, the metal screen 100 may interfere with the adhesive's bond with the wall of the aperture. DE-A-2,843,038 discloses an anchor including a first end which is inserted into an aperture in which the anchor is to be fixed. The anchor includes a brittle plastics cartridge for holding components of a two-part adhesive. As the anchor is inserted into the aperture, the cartridge is broken and disintegrates, and these pieces of brittle plastics material act as a filler for the adhesive. According to this invention, a construction fastener assembly to be secured with an adhesive within an aperture of a structure such as masonry, concrete or metal, comprising: an elongate fastener member having a first end for insertion within the aperture and a second opposite end accessible from the exterior of the aperture after insertion; and, adhesive retaining means secured to said first end of the fastener member for accepting adhesive therein, is characterised in that the retaining means is rigid enough to accept and retain the adhesive therein during insertion within the aperture, and is flexible enough to readily collapse upon insertion of the retaining means and the fastener member into the aperture and to eject the adhesive from the retaining means into the aperture to secure the fastener member in it. The adhesive retaining member enables a measured amount of adhesive to be applied within a prescribed aperture of a structure which releases the adhesive upon insertion of the retaining member and fastener within the aperture and does not interfere with the bonding power of the adhesive. When applied to ceilings it also reduces the potential for dripping. The retaining member preferably is formed from plastic or metal as a tubular screen, a bellows, or a perforated or slotted member and accepts a predetermined amount of adhesive therein. Thus, the correct amount of adhesive required for the prescribed aperture and fastener member is utilized to reduce wasting of adhesive and squeeze out of adhesive from the aperture while providing the desired adhesion. Preferred embodiments of construction fasteners in accordance with this invention will now be described with reference to the accompanying drawings, in which:- FIG. 1 is a perspective view of an anchor and adhesive retaining member of the invention illustrated being filled with an adhesive; FIG. 2 is a perspective partial sectional view of the anchor and adhesive retaining member of the invention illustrated being inserted within an aperture of a structure; FIG. 3 is a side elevational view of the anchor and adhesive retaining member of the invention illustrated in its final position within the aperture; FIG. 4 is a side elevational view of an intermediate insertion position of the anchor and adhesive retaining member of the invention illustrating the adhesive being expelled from the retaining member as it collapses within the aperture; FIG. 5 is a side elevational view of another embodiment of the present invention illustrating a bolt and an adhesive retaining member of the invention secured within an aperture; FIG. 6 is a side elevation view of a prior art fastener and metal screen illustrated within an aperture of a structure; and FIG. 7 is a side elevational view of another embodiment of the present invention illustrating a bolt and an adhesive retaining member of the invention. Referring to FIG. 2, a construction fastener of the invention is generally designated by the reference numeral 10. The fastener 10 preferably is secured within an aperture 12 of a structure 14, such as masonry, concrete, metal or any similar structure, with an adhesive, such as epoxy or the like, generally illustrated in FIG. 1 with the reference numeral 16. The fastener 10 substantially includes a fastener member 18, a cap 20 and an adhesive retaining member 22. For ease of use, the fastener 10 is provided as a unitary, one-piece article as described in detail below. Alternatively, the fastener 10 can be assembled at a job site prior to use. As FIGS. 1 to 4 illustrate, the fastener member 18 and cap 20 substantially are similar to the anchor and cap of above-referenced U.S. Patent No. 5,263,804, the disclosure of which hereby is incorporated by reference. The fastener member 18 preferably is made of metal, such as zinc-plated steel, but the particular material can vary and can be plastic or similar material if desired. Alternatively, as FIG. 5 illustrates, the fastener 10b can be a threaded bolt 18b with the attached adhesive retaining member 22b which does not include any cap. Preferably, the bolt 18b has an end 19 which is pointed along an edge for line contact within the aperture 12. For ease of description the present invention will be described as it applies to the anchor type fastener member 18. As FIG. 2 illustrates, the fastener member 18 includes a first distal insertion end 24 and a second opposite proximal end 26 which is accessible from the exterior of the aperture 12. To resist extraction or pull out of the fastener 18 from the aperture 12 after setting of the adhesive 16, the fastener 18 includes a plurality of major grooves 28 and a plurality of minor grooves 30. The major grooves 28 are positioned along the length of the fastener member 18 proximate the first end 24. The minor grooves 30 are positioned between the major grooves 28 and the second end 26. Although three major grooves 28 and two minor grooves 30 are illustrated, the number, shape and position of the major and minor grooves 28 and 30 can vary. In order to resist rotation of the fastener member 18 within the aperture 12 after setting of the adhesive 16, the fastener member 18 can include a plurality of longitudinal splines or flats 32. The splines 32 are positioned proximate the second end 26 of the fastener member 18 and extend a predetermined length along the fastener member 18, which can vary. As FIG. 2 illustrates, the second end 26 of the fastener member 18 includes an axial threaded bore 34 which extends a predetermined distance within the fastener member 18. The bore 34 can accept a threaded bolt (not illustrated) or other member for securing another article thereto. The cap 20 protects the threaded bore 34 and prevents debris and adhesive 16 from entering the bore 34 before use. The cap 20 also assists in seating the fastener member 18 to a desired depth within the aperture 12 so that proper tensile strength can be achieved. Structural details of the cap 20 are provided in above-referenced U.S. Patent No. 5,263,804. The adhesive retaining member 22 is formed as a tubular member having first and second open ends 36 and 38. The adhesive retaining member 22 preferably is formed from plastic, such as plastic screen, film or metal, and is flexible enough to readily collapse as described below yet rigid enough to accept and retain the adhesive 16 therein during insertion within the aperture 12. The particular material and structure of the adhesive retaining member 22 can vary so long as it functions as described herein. When the adhesive retaining member 22 is formed from screen, the screen size preferably is selected so that the adhesive 16 does not flow through the screen when initially injected into the retaining member 22 before insertion into the aperture 12, due to the viscosity of the adhesive 16. One of the ends 36 or 38 is secured to the first distal end 24 of the fastener member 18, such as with an adhesive, spot welding, ultrasonic welding or any other method. Alternatively, the retaining member 22 can be secured to the distal end 24 of the fastener member 18 with a snug press fit, as FIG. 7 illustrates. For ease of description, the end 36 of the adhesive retaining member 22 will be described as secured to the fastener member 18. The end 36 of the adhesive retaining member 22 is inserted over the first end 24 of the fastener member 18, tightened within one of the major grooves 28 and then secured therein with a spot or ultrasonic weld. Alternatively, as FIG. 7 illustrates, the end 36 of the adhesive retaining member 22 can be press fit over a mounting post 25 formed on the distal end 24 of the fastener member 18. The length and diameter of the adhesive retaining member 22 is selected so that when secured to the fastener member 18 it can be filled with a desired amount of adhesive 16 to provide the exact amount of adhesive 16 to optimize anchor performance. In the embodiment of FIG. 5, the adhesive retaining member 22b is secured to the last few threads of the bolt 18b. The dimensions of the adhesive retaining member 22 are selected so that the required amount of adhesive 16 is supplied within the aperture 12 for a given size aperture 12 and fastener member 18. Such an amount provides the desired bonding and pull out force while reducing the amount of wasted adhesive 16 and preventing squeeze out and dripping of adhesive 16 from the aperture 12. In use, the aperture 12 is drilled into the structure 14 and thereafter cleaned of debris. As FIG. 1 illustrates, the adhesive retaining member 22 then is filled with the adhesive 16. As FIG. 2 illustrates, the filled adhesive retaining member 22 and attached fastener member 18 then are inserted within the aperture 12. As FIG. 4 illustrates, upon engagement of the end 38 of the adhesive retaining member 22 with the bottom of the aperture 12, the adhesive retaining member 22 begins to collapse. During collapsing of the adhesive retaining member 22, adhesive 16 is forced out of the open end 38 and, if a screen is utilized, out of the screen openings substantially in the direction of arrows "A" into the aperture 12 and about the fastener member 18. As FIG. 3 illustrates, due to the portioned amount of adhesive 16 within the adhesive retaining member 22, substantially the entire area within the aperture 12 about the fastener 18 is filled with adhesive 16. Accordingly, the proper bond and pull out strength are provided without under-filling the aperture 12 or providing excess waste or squeeze out of adhesive. The fastener 10 is particularly useful when the structure 14 is a ceiling. In such a situation, the adhesive typically drips out before installing the fastener. The adhesive retaining member 22 and fastener member 18 readily can be inserted vertically within the aperture 12 without adhesive 16 falling out of the adhesive retaining member 22 after filling.

Claims: A construction fastener assembly (10) to be secured with an adhesive (16) within an aperture (12) of a structure (14) such as masonry, concrete or metal, comprising: an elongate fastener member (10) having a first end (24) for insertion within the aperture (12) and a second opposite end (26) accessible from the exterior of the aperture after insertion; and, adhesive retaining means (22) secured to said first end (24) of the fastener member (10) for accepting adhesive (16) therein, is characterised in that the adhesive retaining means (22) is rigid enough to accept and retain the adhesive (16) therein during insertion within the aperture (12), and is flexible enough to readily collapse upon insertion of the retaining means (22) and the fastener member (10) into the aperture (12) and to eject the adhesive (16) from the retaining means (22) into the aperture (12) to secure the fastener member (10) in it. A fastener assembly according to claim 1, wherein said retaining means (22) can accept a predetermined amount of adhesive therein for providing the correct amount of adhesive to securely attach said fastener (10) into an aperture of prescribed size in the structure, and thereby reduce waste adhesive (16), prevent adhesive (16) from squeezing out of the aperture (12) and avoid under filling of the aperture (12). A fastener assembly according to claim 1 or 2, wherein said retaining means (22) is formed from plastic. A fastener assembly according to claim 3, wherein said plastic retaining means (22) is formed as a tubular screen. A fastener assembly according to claims 3 or 4, wherein said retaining means (22) are formed by extrusion. A fastener assembly as defined in claim 1 or 2, where said retaining means (22) are formed from plastic film, metal foil or a woven material. A fastener assembly according to any one of the preceding claims, wherein said fastener member (10) is formed as an anchor. A fastener assembly according to any one of claims 1 to 6, wherein said fastener member (10) is formed as a bolt (10b).

Inventors: ERNST RICHARD J, TIMMERMAN MARK S, ERNST, RICHARD J., TIMMERMAN, MARK S.
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 1995
Main classification: F16B13
IPC codes: F16B13