Patent Application
20060033336
The present invention relates to methods and apparatus for forming connections within structural elements, and, in particular, to weld-free connectors and connections within overhead roadway signage and structures and methods of forming such connectors/connections.
Motorists rely upon roadway signage and structures to receive important information (e.g., information regarding highway exits, distances to approaching municipalities, gas-food-lodging, traffic conditions) and to ensure their safety (e.g., via traffic signals, light poles, warning beacons). To guarantee maximum visibility, these structures are often very large and are constructed such that they overhang the roadway. Thus, there could be significant adverse consequences (e.g., fatalities, damage to vehicles and/or roadways, increased traffic) if the structures were to fall.
At present, the majority of overhead roadway structures utilize one or more welded metal connections. For example, a cantilevered overhead roadway structure (e.g., a light pole) generally utilizes two or more welded metal connections, including at least one connection between the base plate and the vertical column and at least one connection between the vertical column and the horizontal mast. These welded connections are vulnerable to fatigue-based failure due to the natural stresses placed thereupon, the aging of the materials from which they are constructed, and the effects of precipitation (e.g., rain, snow), harmonic vibration (due to, e.g., galloping, natural wind gusts, and “truck” gusts from passing motor vehicles), and human intervention (e.g., road salt used to treat snow and ice, leaked antifreeze, vandalism).
Those who design overhead roadway signage and structures have developed or made use of design methodologies to estimate when such structures may undergo failure. However, the resultant designs are not guaranteed to be accurate, mostly due to the inability to precisely estimate the many conditions, especially the fatigue characteristics of welded joints. This is because welding induces highly variable residual stresses, which, in turn, can cause premature fatigue-based failure. Also, welded designs can be subject to fatigue-based failure at stress levels much lower than would be anticipated based on the strength of the materials being welded. Moreover, conditions such as runaway galloping caused by site-sensitive harmonic vibration can in turn cause a structure to undergo catastrophic failure well in advance of a predicted date. And even when such design methodologies are ultimately accurate, those who oversee the structures still must be trusted to repair and/or replace the structures in accordance with the schedule dictated by the models, otherwise tragedy may occur. Thus, those in the art understood there was a need to extend the lifetime of overhead roadway structures, with the logic being that the longer the structures remain standing, the more likely it will be that someone takes appropriate measures in time to prevent an anticipated or catastrophic failure from occurring.
One attempt to meet this need has been via implementation of so-called “weld-free” connectors. For example, U.S. Pat. No. 6,685,154 B1 to Blyth et al. (the entirety of which is incorporated by reference herein), teaches weld-free connectors for use in erecting light poles and the like. In an embodiment of the Blyth et al. patent, a first connector is provided to join a tapered column to a base and a second connector is further provided to join a tapered mast to the tapered column. The joint regions between the connectors and the structural elements are closed in assembly. In addition, torsion bars such as bolts or pins are pasted through the joints to provide torque resistance. Lastly, neoprene pads are placed in the joint regions in order to provide vibration dampening.
Although use of the Blyth et al. weld-free connectors in place of traditional welded connections may increase the lifetime of the structures in which they are used, installation of such connectors has proven to be quite difficult and time-consuming, so much so that those entrusted with building, purchasing and installing overhead roadway structures have not sought to implement them on a widespread basis.
Therefore, a need exists for weld-free connectors/connections that can be utilized to extend the lifetime of overhead roadway structures without necessitating added cost or complexity in their implementation.
These and other needs are met by the present invention, which provides weld-free connectors for connecting two or more members or elements, as well as methods for forming such weld-free connectors. Despite being weld-free, the connectors formed in accordance with the present invention provide excellent vibration dampening and are highly resistant to fatigue-based cracking and failure. Such weld-free connections can be advantageously substituted for welded connections within roadway signage and other structures in order to prevent or delay fatigue-based cracking and failure caused by stresses and harmonic vibrations that occur due to, e.g., galloping, natural wind gusts and so-called truck gusts.
In accordance with an exemplary aspect of the present invention, a non-welded (i.e., weld-free) connector for joining a plurality of structural members includes at least a first and second members, wherein the first member is in tactile communication with the second member to define a joint region. A sleeve is positioned around (e.g., substantially centered over) the joint region of the first and second structural members to define a cavity between the sleeve and at least the joint region of the first member and the second member. A predetermined quantity of polymeric material is introduced within the cavity, and adheres to at least the joint region of the first and second members. The cavity is sealed so as to contain the polymeric material, which, once cured, forms a weld-free connection/connector at the joint region.
In accordance with another exemplary aspect of the present invention, a non-welded connector for joining a plurality of structural members includes at least a first member and a second member, wherein a portion of the first member is disposed at least partially within a portion of the second member so as to be in tactile communication with the first member at a joint region. The first member has a diameter less than that of the portion of the second member in which the portion of the first member is disposed, so as to define a cavity between the first member and the second member. A predetermined quantity of polymeric material is introduced within the cavity, wherein the polymeric material adheres to at least the joint region of the first and second members so as to provide a weld-free connection once the polymeric material has cured.
In accordance with yet another exemplary aspect of the present invention, a non-welded connector for joining a plurality of structural members, includes at least a first member and a second member, wherein a portion of the first member is disposed at least partially within a portion of the second member so as to be in tactile communication with the first member. The first member has a diameter less than the portion of the second member in which the portion of the first member is disposed so as to define a cavity between the first member and the second member. An object (e.g., a split ring) is in tactile communication with the first member and the second member to define a joint region between the first member and the second member. A predetermined quantity of polymeric material is introduced within the cavity, wherein the polymeric material adheres to at least the joint region of the first and second members so as to provide a weld-free connection once the polymeric material has cured.
In accordance with these exemplary aspects (and, if desired, still other aspects) of the present invention, the first member and the second member (and, if present, the sleeve) can be made of the same material or a different material, wherein suitable such materials, by way of non-limiting example, can be metal-based materials such as iron, steel and aluminum.
In accordance with these exemplary aspects (and, if desired, still other aspects) of the present invention, the polymeric material is selected in order to provide such properties as proper adhesion, excellent vibration dampening, torsion resistance, and/or fatigue resistance. By way of non-limiting example, the polymeric material can be a polyurethane material, e.g., an unpigmented polyurethane comprised of a predetermined ratio of a resin and an isocyanate.
In accordance with another exemplary aspect of the present invention, a cantilevered structure (e.g., a light pole, a traffic signal) is provided and includes a base, a substantially vertically disposed column that is connected to the base (e.g., by a flange through use of at least one fastener), and a substantially horizontally disposed mast. The column has a predetermined height and can be made of a predetermined material (e.g., iron), and the mast has a predetermined length and can be made of a predetermined material (e.g., aluminum). Either or both the mast and the column can have substantially constant or tapered diameters.
One or more non-welded connections can be formed within the cantilevered structure. For example, a first non-welded connection can be provided between the vertical section of the base and the column, and can be formed of a predetermined quantity of a first polymeric material within a first cavity defined between the vertical section of the base and the column. A second non-welded connection can be provided between the column and a vertically disposed sleeve that surrounds at least a portion of the column, and can be formed of a predetermined quantity of a second polymeric material (e.g., the same or different polymeric material as the first polymeric material) within a second cavity defined between the vertical sleeve and the column. An optional third non-welded connection can be provided between the mast and a horizontally disposed sleeve that is orthogonal to the column and-that surrounds at least a portion of the mast, and can be formed of a predetermined quantity of a third polymeric material (e.g., the same or different polymeric material as the first polymeric material and/or the second polymeric material) within a third cavity defined between the horizontal sleeve and the column. If the third weld-free connection is not included, it can be replaced by one or more other connections known in the art, e.g., a slip fit joint.
Still other aspects, embodiments and advantages of the present invention are discussed in detail below.
For a fuller understanding of the nature and desired objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying figures, wherein like reference characters denote corresponding parts throughout the views, and in which:
Referring initially to
The first member 20 has a first end 22 and a second end 24, and the second member 30 has a first end 32 and a second end 34. Prior to being joined together, the first member 20 and the second member 30 are placed in tactile communication. According to an exemplary embodiment of the present invention, and as shown in
The abutting first and second members 20, 30 are then placed within a surrounding sleeve 40. The sleeve 40 is positioned with respect to the abutting members 20, 30 such that at least a portion of the sleeve surrounds at least a portion of each of the first and second member, thus, in turn, ensuring that the sleeve will surround at least the abutting ends 22, 34 of the first and second members. According to an exemplary embodiment of the present invention, and as depicted in
In accordance with an alternate embodiment of the present invention, the first and second members 20, 30 are positioned such that their ends 22, 34 are not abutting, but instead are in close proximity. As with the exemplary embodiment described above, however, the non-abutting ends 22, 34 generally are surrounded by the sleeve 40.
The first and second members 20, 30 and the sleeve 40 can be made of the same or different materials; however, in an exemplary embodiment of the present invention, the first member, the second member and the sleeve are formed of the same metal-based material, wherein suitable such materials include, but are not limited to iron, steel and aluminum.
As shown in
The cavity 50 is sealed at each end as is known in the art, e.g., through use of a plugging object 55 such as an O-ring made of silicone, rubber, a thermoplastic resin, or a thermoset resin, or through use of weather stripping, or via a chemical sealant. Alternatively, one or more of the O-ring seals 55 can be formed integral with the sleeve 40. A predetermined quantity of polymeric material 60 is introduced within the sealed cavity and allowed to cure to form the non-welded connection at the joint 10. This can occur as is generally known in the art, e.g., by pumping, injecting or otherwise introducing the polymeric material into the cavity 50 through an injection port (not shown). A second port (not shown) can be provided away from the injection port in order to assess when the cavity 50 is full—that is, the polymeric material 60 is introduced until it starts to emerge from the second port, thus indicating that the cavity has been completely or at least substantially filled with the polymeric material.
The specific choice of polymeric material 60 for filling the cavity 50 can vary according to several factors, including, but not limited to the chosen materials for first and second members 20, 30, the width of the cavity 50, the diameter of the members, and the purpose for joining the first and second members. Generally, the chosen polymeric material 60 has at least one of the following materials properties: proper adhesion when used in association with a wide range of materials; excellent vibration dampening properties; torsion resistance; lack of susceptibility to degrading conditions (e.g., road salt, antifreeze); and fatigue resistance even when subjected to high vibrational loads. Polymeric materials exhibiting such properties include, but are not limited to urethane materials, such as polyurethane. An exemplary polyurethane material is unpigmented polyurethane comprised of a resin and an isocyanate. By way of non-limiting example, the polyurethane material 60 can be comprised of about 100 parts of a resin commercially available from BASF Corporation of Florham Park, N.J. USA under supply part number NB # 98113-1-256-212 and about 94.3 parts of an isocyanate commercially available from BASF Corporation of Florham Park, N.J. USA under supply part number WVC 3154T. In its cured form, this polyurethane material exhibits the following materials properties:
As the polymeric material 60 is introduced within the cavity 50, it surrounds the first and second members 20, 30, including at their abutting ends 22, 34. Thus, once the polymeric material 60 cures, it will adhere to the first and second members 20, 30, and, in turn, will cause the members to be maintained within their abutting position through a weld-free connection/connector created at joint 10.
Although not shown in
Thus, the present invention provides an important advantage, namely the ability to tailor the length of a plurality of joined members or elements through use of weld-free connections. For example, it is a well known problem in the art that certain types of ductile iron piping are only available in lengths which restrict their use to a limited number of structural applications. However, in accordance with an exemplary embodiment of the present invention, several individual segments of iron piping can be joined via weld-free connections/connectors to form what is in essence a single, joined piece of piping having a tailored length as needed for a particular structural application. That, in turn, will beneficially expand the number of structural applications for ductile iron piping. Moreover, the presence of the polymeric material within the weld-free connections provides highly advantageous shock, blast and earthquakes resistance, plus excellent vibration dampening characteristics.
Referring now to
Referring now to
The embodiments depicted in
The weld-free connections/connectors of the present invention have important uses in practice, including, by way of non-limiting example, replacing traditional welded connections/connectors in certain structures. For example, weld-free connections/connectors of the present invention can be incorporated within roadway structures and signage having cantilever, butterfly or bridge support (i.e., overhead or span-type support) designs, or still other designs. Examples of such roadway structures and signage include, but are not limited to, light poles, highmast luminaries, traffic signal structures, overhead highway signs, and mounted traffic monitoring equipment. Also, the weld-free connections can be beneficially incorporated within any structures (e.g., bridges, buildings) that require increased shock, blast and/or earthquake resistance.
An exemplary cantilevered light pole 100 is shown in
The column 110 has a first end 112 (see
The column 110 and the mast 120 of the light pole 100 can be made of the same material or a different material, wherein suitable materials from which the column and the mast can be made include, but are not limited to, metal-based materials such as iron, steel and aluminum. In accordance with an exemplary embodiment of the present invention, the column 110 is made of an iron material because iron is stronger in compression than tension, and the mast is made of an aluminum material because aluminum is a lightweight metal-based material but also has an excellent strength to weight ratio. Moreover, without wishing to be bound by theory, it is believed that the presence of the polymeric material within the weld-free connections/connectors that are included within the light pole 100 will beneficially reduce the possibility of a galvanic reaction occurring between the iron and the aluminum.
The flanged portion 210 of the base casting is connected to the base 130 by a technique that ensures a reliable and secure connection. According to an exemplary embodiment of the present invention, the flanged portion 210 is connected to the base 130 by a fastening technique (e.g., embedment), through the use of concrete, or via a bolted connection, each as is generally known in the art.
To form the weld-free connection/connector 140 between the column 110 and the base 130, a space or cavity 230 is defined between the inner walls 220 of the column 110 and the outer walls 270 of the vertical section 200 of the base casting. One or more seals 240 (e.g., one or more O-rings) are mounted within the cavity 230, e.g., in the upper and lower parts of the cavity as shown in
As illustrated in
Turning now to
For the optional third weld-free connection 155, a horizontally disposed sleeve 350 is positioned substantially orthogonal to the vertical column 110 in order to slideably receive the open end of the mast 120. A second space or cavity 360 is provided or defined between the mast 120 and sleeve 350, and one or more appropriate seals (e.g., one or more O-rings) or closure devices 370 are provided (e.g., mounted at the upper and lower ends of the cavity) to enclose the second cavity. The enclosed second space or cavity 360 is then filled (e.g., as explained above with respect to
Although the mast 120 in the
Although the present invention has been described herein with reference to details of currently preferred embodiments, it is not intended that such details be regarded as limiting the scope of the invention, except as and to the extent that they are included in the following claims—that is, the foregoing description of the present invention is merely illustrative, and it should be understood that variations and modifications can be effected without departing from the scope or spirit of the invention as set forth in the following claims. Moreover, any document(s) mentioned herein are incorporated by reference in their entirety, as are any other documents that are referenced within the document(s) mentioned herein.
This application claims priority from and incorporates by reference the entirety of U.S. Provisional Patent Application Ser. No. 60/600,622, which was filed on Aug. 11, 2004.
| Number | Date | Country | |
|---|---|---|---|
| 60600622 | Aug 2004 | US |
