The present disclosure generally relates to a base can fastening system. More specifically, the present disclosure relates to a fastening system that retains a nut under a base can flange to engage a bolt inserted from above.
Base cans are generally known in the art and serve as anchoring devices for removably attaching an object. In particular, the base can may be permanently fixed in an underlying material that may not be conducive to attaching the object directly thereto. Similarly, a base can may provide an enclosure for retaining and protecting portions of the object and related equipment. In some cases, the object itself serves as a cover for the enclosure upon attachment to the base can. One common application for base cans is with electrical installations, using the base can as a convenient and standardized receptacle for anchoring an electrical fixture while also protecting its wiring from the elements by containing them therein.
Base cans are often cylindrical in shape, having curved sidewalls and often an at least partial bottom wall. The top end, opposite of the bottom wall if present, is generally at least partially open and includes a flange extending radially inwardly from the circumference of the base can sidewalls. This flange often contains a plurality of threaded base can apertures that are spaced evenly around the circumference of the open top end of the base can. This configuration provides an interface for attaching objects to the base can by inserting couplers, such as bolts from above. In this arrangement, the object attached to the base can effectively closes the base can, which may then be further sealed from the elements by placing intermediate seals or gaskets between the object and the base can before attachment.
One particularly challenging application for base cans is within the context of airport lighting, which relies upon base cans being fixed within the runway to anchor in-runway lighting. Mounting base cans and light fixtures within a runway presents many unique challenges, including the need to withstand tremendous forces of airplanes landing and taking off, the need to support quick repairs and replacements to the light fixtures to avoid runway down-time, and the need to maintain a flush runway surface to ensure the safety of the airplane and its passengers.
The base cans, lighting fixtures, and fastening systems presently known in the art attempt to meet these challenges as follows. The durability of these elements, as well as the specifications of fasteners for attaching light fixtures to base cans, are specified by the Federal Aviation Administration (FAA) to ensure that they can withstand the demands of in-runway installations. The time for repairs and replacements of light fixtures is reduced by using commonly known, threaded bolts (albeit, meeting FAA specifications) to install the fixtures from above, standardizing the process and tools involved. Annular spacers are often used as needed to offset the distance between the base can flange and the object, allowing the installed height to be adjusted until it is flush with the surrounding runway surface.
A seating ring may also be installed between any spacers and the light fixture, which may contain a recessed surface below the upper surface to allow the fixture to be at least partially nested down within the seating ring upon installation. This arrangement may provide additional benefits, such as providing a seal or supporting the fixture by a lip between the upper surface and the recessed surface of the seating ring.
One embodiment of the present disclosure generally relates to a fastening system for coupling an object to a base can. The base can has a flange with an upper surface and a lower surface and defines a plurality of base can apertures through the flange. The object defines a plurality of object openings through the object. The fastening system includes a clip having an upper arm and a lower arm that each extend from a spreader, where the spreader separates the upper arm and lower arm. The clip is configured to engage the flange such that the flange is positioned between the upper arm and the lower arm. A nut has a nut base and a plurality of sides that extend perpendicularly from the nut base. The nut defines a nut opening with internal threads. The clip is configured to retain the nut between the lower arm and the lower surface of the flange such that the nut opening is aligned to a base can aperture of the plurality of base can apertures. A coupling system having a threaded member is configured to couple the object to the base can. When the object is coupled to the base can, the threaded member extends at least through one of each of the plurality of object openings in the object and the plurality of base can apertures in the flange, and the threaded member also extends at least partially into the nut opening to engage the nut.
Another embodiment generally relates to a fastening system for coupling an object to a base can with a coupling system and a nut. The nut has a lip and defines a nut opening. The base can has a sidewall with an upper end, a lower end that is opposite the upper end, and a flange that extends radially inwardly and perpendicularly from the upper end of the sidewall. The flange has an upper surface and a lower surface and defines a plurality of base can apertures through the flange. The object defines a plurality of object openings through the object. The fastening system includes a clip configured to engage the flange of the base can. The clip has a spreader and an upper arm, a middle arm, and a lower arm that are each coupled to and separated by the spreader. The upper arm defines an upper opening, the middle arm defines a middle opening, and the lower arm defines a lower opening. In certain embodiments, the upper opening, the middle opening, and the lower opening are axially aligned. The clip is configured to engage the flange such that the flange is positioned between the upper arm and the middle arm. A spacer is positionable between the upper surface of the flange and the object. The spacer has an upper surface and a lower surface and defines a plurality of spacer openings though the spacer. The lower surface of the spacer further defines a plurality of clip grooves that extend towards the upper surface of the spacer, where the plurality of spacer openings coincide with the plurality of clip grooves. The plurality of clip grooves are configured to accommodate the upper arm of the clip such that the upper arm does not prevent the lower surface of the spacer from contacting the upper surface of the flange when the clip is engaged with the flange and the spacer is positioned between the flange and the object. The clip is configured to retain the lip of the nut between the middle arm and the lower arm such that the nut opening is aligned to one base can aperture of the plurality of base can apertures. When the object is coupled to the base can, the threaded member extends at least through one of each of the plurality of object openings in the object, the plurality of spacer openings, the upper opening of the clip, the plurality of base can apertures in the flange, and the middle opening of the clip, and the threaded member also extends at least partially into the nut opening to engage the nut.
Another embodiment generally relates to a fastening system for coupling an object to a base can. The base can has a sidewall with an upper end and a lower end that is opposite the upper end, where the base can has a flange that extends radially inwardly and perpendicularly from the upper end of the sidewall. The flange has an upper surface and a lower surface and defines a plurality of base can apertures through the flange. The object defines a plurality of object openings through the object. The fastening system includes a clip configured to engage the flange of the base can, where the clip has a spreader and an upper arm, a middle arm, and a lower arm that are each coupled to and separated by the spreader. The upper arm defines an upper opening, the middle arm defines a middle opening, and the lower arm defines a lower opening. In certain embodiments, the upper opening, the middle opening, and the lower opening are axially aligned. The clip is configured to engage the flange such that the flange is positioned between the upper arm and the middle arm. A coupling system has a threaded member. A nut has a lip and a plurality of sides that extend perpendicularly from the lip, where the nut defines a nut opening having internal threads. The internal threads are threadably engageable with the threaded member of the coupling system. The clip is configured to retain the lip between the middle arm and the lower arm. A spacer is positionable between the upper surface of the flange and the object, where the spacer has an upper surface and a lower surface and defines a plurality of spacer openings through the spacer. The lower surface of the spacer further defines a plurality of clip grooves that extend towards the upper surface of the spacer, where the plurality of spacer openings coincide with the plurality of clip grooves. The plurality of clip grooves are configured to accommodate the upper arm of the clip such that the upper arm does not prevent the lower surface of the spacer from contacting the upper surface of the flange when the clip is engaged with the flange and the spacer is positioned between the flange and the object. The clip is configured to retain the lip of the nut between the middle arm and the lower arm such that the nut opening is aligned to one base can aperture of the plurality of base can apertures. When the object is coupled to the base can, the threaded member extends at least through one of each of the plurality of object openings in the object, the plurality of spacer openings, the upper opening of the clip, the plurality of base can apertures in the flange, and the middle opening of the clip, and the threaded member also extends at least partially into the nut opening to engage the nut.
The drawings illustrate the best mode presently contemplated of carrying out the disclosure. In the drawings:
Embodiments of the base can fastening system are described herein.
Through observation and product development, the present inventors have identified problems with base cans and fastening systems known in the art. One application in which this was identified is within the field of runway light fastening systems. Although this disclosure often discusses the presently claimed subject matter in the context of runway lighting, it should be recognized that the following relates to attaching any object to any structure analogous to a base can.
One exemplary problem identified by the present inventors is that the threaded openings or apertures in the flange of presently known base cans often become stripped over time. These are also prone to bind with a bolt inserted therein, resulting in the bolt breaking off and the broken portion of the bolt remaining within the threaded opening of the base can flange. In the context of runway lighting fixtures, this problem is further exacerbated by the fact that the presently known and used base cans are not regulated to the same specifications as the fasteners used to attach fixtures to them, resulting in base cans being made of a lower grade material that is more likely to become damaged.
Since the integrity of fastener systems for attaching objects such as lights to a runway is critical to the safety of both airplanes and their passengers, damaged base cans must be repaired such that each light fixture remains fixed to the base can with the necessary quantity of fasteners and corresponding threaded base can apertures in fully functional form. In the case of a stripped aperture thread, there is little that can be done to restore the thread integrity while allowing the same standardized bolt to be used in that aperture. In the case of a broken bolt, the fragment must be removed or otherwise drilled out in order to restore an open aperture through the flange. However, this too may result in widening of the aperture diameter or damage to the threads, leading to the inability to engage the aperture using the same standardized bolt used in the other apertures.
Furthermore, any such repairs to stripped threads, or efforts to remove a broken bolt fragment, are further complicated in the context of a base can assembly that is permanently fixed within a concrete runway surface, making repairs both difficult and expensive. The present inventors have identified a need to improve the speed and efficacy of making such repairs within the narrow time window that a technician has available between runway uses, as well as a solution to prevent damage and/or to accommodate repair more readily for future base cans being installed.
One of the most significant expenses for repairing damaged base cans arises from stripped threads, which require the base can to be removed from the concrete runway surface in order to install a new base can having fully functioning threads. Since a runway must have an exceptionally flat and even surface, removal and replacement of a base can generally requires a section of the runway concrete surrounding the base can to be removed and re-poured in conjunction with the newly installed base can.
In practice, the base can 1 is permanently fixed within the concrete of a runway. Once the concrete has hardened, an appropriate number of spacers 44 are placed on the base can 1 to ensure the desired overall installation height, a seating ring 50 is placed on the spacers 44, and an object 90 is secured to the base can from above by inserting a series of coupling systems 18. Any subsequent repairs are performed on the runway, as the base can 1 is fixed within the concrete.
While
Beyond the improvement for new base cans 1, the present inventors have designed and developed the presently disclosed fastener system to allow an existing base can 1 to be restored to functioning condition after the threaded base can apertures 8 have been damaged or rendered otherwise unusable. Specifically, the present inventors have developed a fastening system 100 that enables a new nut 12 having fully functional threads within the nut opening 16 defined therein to be retained under a damaged base can aperture 8 of the base can flange 3, allowing the threaded nut opening 16 to be engaged by a coupling system 18 to couple an object 90 to the base can flange 3 regardless of the condition of the threads within the base can aperture 8.
It should be noted that although this disclosure generally refers to base cans 1 oriented with the open end facing upwardly, and in the context of in-runway lighting, the present disclosure anticipates use of the disclosed fastening system for any base cans, such as overhead lighting or other applications.
The present inventors have identified another embodiment of the present disclosure as being particularly advantageous in the context of runway repair. Frequently, runway resurfacing requires an extension 60 to be placed above flange 3 of base cans 1 set within the runway. These extensions 60 have been observed to shift relative to the base can 1 over time and through use, causing shearing or other damage any coupling systems 18 used to couple an object 90 to the base can 1. There are presently no known methods or devices for solving this problem.
Returning to the embodiment shown in
It should be recognized that while the openings in the clip 20 are in some embodiments depicted as circular holes, these openings may have other shapes and also need not be enclosed, such as shown for lower opening 32.
The inventors have further developed an improvement to new base cans 1 to accommodate the presently disclosed fastening system 100 for use in repairing newly manufactured base cans 1 as they become damaged in the future. For example, the embodiment of
In other embodiments, the fit and friction between the upper surface 37 of the middle arm 36 and the lower surface 5 of the flange 3 is sufficient to maintain alignment of the clip 20 to the flange 3 without an alignment feature 40 and chamfer 9. Therefore, the presently disclosed fastening system 100 also functions with existing base can installations.
In base can 1 assemblies known in the art, a pair of wedge lock washers 11 are routinely installed between the object 90 and the coupling system 18 in circumstances where vibrations may cause loosening over time (shown in
While the presently disclosed fastening system 100 can incorporate wedge lock washers 11 as known in the art, the present inventors have further identified improvements by instead using a nut 12 having variable pitches within the nut opening 16. In the embodiment of
As discussed above, the presently known base can systems commonly include the use of spacers, as necessary, to ensure that the final installation of an object 90 on the base can 1 remains at a height that is substantially flush with the runway surface. However, the present inventors have also identified that the use of a clip that attaches onto the base can flange would interfere with the presently known spacers making contact with the base can flange upper surface. Accordingly, the present inventors have developed an improved spacer 44 to accommodate the use of the clip 20 in the presently disclosed fastening system, as shown in
The spacer 44 contains one or more clip groove 47 in the lower surface 46 of the spacer 44 that each substantially correspond a spacer opening 48 through the spacer 44. The clip groove 47 is configured to be at least the size of the upper arm 24 of the clip 20 such that the clip groove 47 may fully accommodate the upper arm 24 therein when the spacer 44 is placed on the upper surface 4 of the base can 1 flange 3 with a clip 20 attached thereto. The clip groove 47 may be substantially larger than the dimensions of the upper arm 24 of the clip 20, and in fact, the portion of the spacer 44 comprised of clip grooves 47 may be substantially greater than the portion of the lower surface 46 that makes contact with the upper surface 4 of the base can flange 3.
An optional seating ring 50 may be placed on the upper surface 45 of the spacer 44 shown in
In this arrangement, the object 90 is coupled or secured to the base can 1 by inserting a coupling system 18, such as a bolt, into an opening 92 in the object 90, through a seating ring opening 58 in the seating ring 50, through a spacer opening 48 in the spacer 44, through the upper opening 25 in the upper arm 24 of the clip 20, through the base can aperture 8 of the flange 3, through the middle opening 39 of the middle arm 36 in the clip 20, and finally into and threadably engaging the nut opening 16 of the nut 12 within the lower opening 32 of the lower arm 28 of the clip 20.
As discussed above, the present disclosure anticipates clips 20 that do not include a middle arm 36, but instead retain the nut 12 between the base can flange 3 and the clip 20 by merely the lower arm 28. For example, the lower arm 28 may comprise a pocket shaped recess to prevent rotation of the nut 12 and to upwardly retain the nut 12 against the lower surface 5 of the flange 3 when the clip 20 is attached onto the base can flange 3.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
This application claims the benefit of U.S. Provisional Patent Application No. 62/349,928, filed Jun. 14, 2016, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62349928 | Jun 2016 | US |