The field of the invention is fastener systems and more particularly explosively driven fastener systems.
The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
These and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Fastener systems have been developed to drive fasteners through hard structures, such as wood, concrete, masonry and steel. One example of a type of fastener system used to drive fasteners through hard structures is an explosively-driven fastener system. Typically, an explosively-driven fastener system comprises a tool that receives a fastener and a charge. When the charge is detonated, the fastener is driven from the tool and through a hard structure by gas produced by the detonated charge.
While typical driven fastener systems assist in driving a fastener through a hard surface, several drawbacks can make limit the application of such fastener systems. For example, fastener systems can overdrive the fastener through the structure, which can limit some fastener systems to specific structures. In another example, some fastener systems can produce excessive sound levels and/or provide inadequate penetration of the fastener through a structure due to misalignment of the fastener with respect to the structure.
U.S. Pat. No. 3,172,123 to Helderman discloses an explosive actuated tool for driving a fastening stud. The fastening stud is inserted into the bore of the tool adjacent to an explosive charge. When the stud strikes a work piece the stud impacts the charge to produce an explosion that drives the stud into the work piece. Helderman discloses that a guide washer can be affixed to the stud and placed in the muzzle end of the tool to align the stud in the bore. Furthermore, Helderman discloses ports that can be used to couple the bore with an expansion chamber to dissipate the explosive force of the charge and reduce recoil.
Similarly, U.S. Pat. Nos. 3,797,721 and 4,899,919 to Clump discloses a fastening system for energizing a fastener into a material (e.g., concrete) comprising a centering member/guide washer disposed on the fastener. Venting apertures or pathways receive expanding gases as the head of the fastener is driven past the venting apertures or pathways to relieve the pressure driving the fastener. U.S. Pat. No. 5,423,469 to Armstrong and U.S. Pat. No. 8,397,969 to Masas describe other venting systems for self-powered fastener systems.
Although these references address some drawbacks of fastener systems, it should be appreciated that additional improvements can further reduce or eliminate drawbacks in such systems. Thus, there is still a need in the art for improved fastener systems.
The inventive subject matter provides apparatus, systems, and methods in which an improved fastener system can reduce, or even eliminate, drawbacks encountered in typical fastener systems. For example, fastener systems are contemplated that (i) provide optimal penetration of a fastener into a work surface, (ii) align and guide the fastener into the work surface, and (iii) reduce the sound level of the system. Thus, contemplated systems maintain the orientation of the fastener from insertion into a fastener tool until optimum penetration to thereby provide additional stability and guidance of the fastener, and improve performance of the fasteners by reducing failures and spalling.
In a contemplated embodiment, a tool for driving a fastener into a work surface comprises an elongated member having a longitudinal bore that is accessible through an opening. The longitudinal bore comprises a first inner diameter, and a recess disposed at the opening comprises a second inner diameter. Typically, the second inner diameter is larger than the first inner diameter. A first vent having an inlet is disposed on an inner surface of the recess, and a second vent having an inlet is disposed on an inner surface of the longitudinal bore. It should be appreciated that the vent locations are suitable to capture propellant gases produced by an explosive charge to thereby reduce the volume of sound and prevent overdriving the fastener through the work surface.
The first vent can be longitudinally separated from the second vent by a first distance. Typically, the first distance is greater than or equal to the length of a head portion of the fastener. It should be appreciated that the distance between the first vent and the second vent can impact the driving force of the fastener. On the one hand, if the first vent and the second vent are separated by too far of a distance then there may not be enough driving force to adequately drive the fastener through the working surface. On the other hand, if the first vent and the second vent are too close to each other then there may be a risk of overdriving the fastener. Typically, the first vent is adjacent to a first plurality of vents, and the second vent is adjacent to a second plurality of vents.
A chamber can be circumferentially disposed about the elongated member to receive any propellant gases through an outlet of each of the first and second vents. The first and second vents are typically angled with respect to a longitudinal axis of the elongated member. In other words, the first and second vents typically extend at an angle away from the distal end of the elongated member. Furthermore, the second vent can be flared, such that the vent gradually widens from the inlet to the outlet.
In another aspect, a fastener system comprising a tool, a fastener, and a washer is contemplated. The tool has an elongated member having a proximal end and a distal end, and a longitudinal bore having an inner diameter. The longitudinal bore is accessible through an opening in the distal end of the elongated member. The fastener comprises a head portion and a body portion whereby the inner diameter of the longitudinal bore of the tool is sized and dimensioned to receive the head portion of the fastener. The body portion of the fastener has a first diameter and a second diameter that meet at a step. The washer has a through-hole sized and dimensioned to receive the first diameter of the fastener, and the through-hole is smaller than the second diameter. When the washer is coupled with the elongated member, it should be appreciated that the step of the fastener helps uncouple the washer from the elongated member as the fastener is driven out of the longitudinal bore.
The tool of the fastener system can comprise a first vent and a second vent. The distance between the first and second vents and the distal end of the tool is suitable for capturing gases produced when firing the tool to improve penetration of the fastener. Typically, the step of the fastener is positioned on the body portion of the fastener such that the head portion of the fastener passes the first vent before the step contacts the washer after the tool is fired.
In another aspect, a fastener system comprising a tool and a washer is contemplated. The tool is typically for driving a fastener into a work surface. The tool comprises an elongated member having a proximal end and a distal end, and a longitudinal bore having an inner diameter. The longitudinal bore is accessible through an opening in the distal end of the elongated member. The tool further comprises a recess disposed at the opening having a tapered inner diameter. Typically, the tapered inner diameter gradually increases towards the distal end. The washer has an outer diameter that is larger than a portion of the tapered inner diameter of the recess. It should be appreciated that the washer is preferably sized and dimensioned to seal the vent when the washer is inserted into the recess.
Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
The following discussion provides example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
Also, as used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously.
Washer 202 has a through-hole that receives fastener 200. Washer 202 can comprise at least one of a metal and a polymer. For example, washer 202 can comprise all metal, all nylon or some other hard polymer, or a combination of a metal and polymer (e.g., a steel washer with a nylon coating). Typically, washer 202 can flex to fit into a recess of the barrel (see, e.g., recess 121 in
Clip 204 can also be coupled to fastener 200 whereby a fastening tool can be used to drive fastener 200 into a work surface to attach clip 204 onto the work surface. It is contemplated that clip 204 can be an angle clip (e.g., L-shaped clip or 90° angle clip, 120° angle clip, etc.), a conduit clip, and any other suitable attachment device as desired by the user. Clip 204 can be used to attach a wire or other item to the work surface.
A side view of fastener 200 is shown in
Projections 214 can be disposed on one end of fastener 200 that are used to detonate a charge within a fastening tool. Preferably, projections 214 are disposed on an end of fastener 200 that is proximal to head portion 206. Projections 214 comprise a pointed apex that assists in detonating the charge.
A washer 202 can comprise an annular flange 218 as shown in
While not shown, it is contemplated that annular flange 218 can comprise a coating (e.g., nylon coating) to more easily flex and slide into the recess of the barrel. In other contemplated embodiments, washer 202 can be a solid piece (i.e., no empty areas between outer surface and through-hole 220) with through-hole 220. In such embodiment, washer 202 can comprise a polymer material that is flexible to fit within the recess of the barrel.
Through-hole 220 is sized and dimensioned to receive a body portion 208 of fastener 200. In some embodiments, through-hole 220 engages body portion 208 of fastener in a friction fit. It is contemplated that through-hole 220 is sized and dimensioned to receive the first diameter of fastener 200 (i.e., body portion 208 on side of step 210 distal of head portion 206) and that through-hole 220 is smaller than the second diameter of fastener 200 (i.e., body portion 208 on side of step 210 proximal of head portion 206). When fastener 200 is driven out of the fastener tool, it is contemplated that through-hole 220 can expand to accommodate the second diameter, such that head portion 206 will rest on annular flange 218 when fastener 200 is driven into a work surface.
An exemplary illustration of use of a fastener tool to drive a fastener is shown in
Barrel 5 and gas expansion cylinder shield 3 form a chamber 305 that is fluidly coupled with vent outlets 125 and vent outlets 130. Chamber 305 allows gases from the ignition and explosion of charge 300 to escape, thereby reducing the velocity of fastener 200 and reducing the noise of the explosion, as will be further explained in more detail below.
In the firing position, this fastener system provides three points of stabilization that guide fastener 200 in a straight path as it penetrates work surface 400: (i) the first point of stabilization is provided by the tight tolerances between head portion 206 and the inner diameter of bore 135; (ii) the second point of stabilization is provided by tight tolerances between recess 121, washer 202, and body portion 208; (iii) the third point of stabilization is provided by tight tolerances between body portion 208 and clip 204, in combination with the friction between the distal end of barrel 5, clip 204, and work surface 400. Since washer 202 is held in place within recess 121 (due to the tapered walls of recess 121 and the flexing of annular flange 218), the three points of stabilization provide guidance and stability throughout the majority of fastener 200's travel time. This reduces the amount of failures compared to conventional zero standoff tools.
In the fully seated and firing position, projections 214 on head portion 206 of fastener 200 are pressed into charge 300, causing charge 300 to ignite and explode.
Once head portion 206 of fastener 200 reaches recess 121, gas 500 can move freely into chamber 305, as shown in
Thus, specific compositions and methods of fastener systems have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure. Moreover, in interpreting the disclosure all terms should be interpreted in the broadest possible manner consistent with the context. In particular the terms “comprises” and “comprising” should be interpreted as referring to the elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps can be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
This application claims the benefit of priority to U.S. Provisional Application Ser. No. 62/189,047 filed on Jul. 6, 2015. All extrinsic materials identified herein are incorporated by reference in their entirety.
Number | Date | Country | |
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62189047 | Jul 2015 | US |