Static structures (e.g. – buildings) – Module or panel having discrete edgewise or face-to-face... – Having integral key
Reexamination Certificate
1999-05-13
2001-09-11
Friedman, Carl D. (Department: 3635)
Static structures (e.g., buildings)
Module or panel having discrete edgewise or face-to-face...
Having integral key
C052S309900, C052S651020, C052S749100
Reexamination Certificate
active
06286281
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to poles for supporting utility lines and more specifically to a hollow tapered pole formed from a plurality of pultruded composite panels.
Presently utility line poles are generally made of wood, steel or concrete. Wood poles are known by the industry to have many existing and long-term problems. These include supply, the use of environmentally questionable treatment such as creosote and pentachlorophenol, and the issue of environmental attack on the life of the pole due to problems with fungus, rot and animal attack. Wood continues to have questions relative to the environmental safety of the preservatives. In some cases, the disposal of the poles has presented questions resulting in unclear direction regarding landfill acceptability and recycling. Existing alternatives include tubular light duty steel poles, which are designed in a twelve-sided configuration, and concrete poles. Both provide equivalent performance to wood, but have significant problems regarding weight, shipping constraints, corrosion and in some cases first costs. Wood appears to be the popular choice of utilities if availability exists due to primarily low initial costs.
In U.S. Pat. No. 5,222,344, the inventor, Johnson, discloses a utility pole having an upper section formed of pultruded composites. In one embodiment, an interior lattice of composite members forms an elongated open celled beam which is enclosed in a preferably composite outer skin.
There are some utility poles utilizing composite processes such as filament winding and centrifugal casting. The drawback to these processes are that they require a mold or a mandrel. Also the maximum height for these type of composite poles appears to be in the 50-55 foot range.
The need for utility poles in the height range of 65-120 feet is presently being served by wooden poles. These poles are quite expensive and the time delay from ordering to delivery is long. Light duty steel poles and concrete poles in this height range are expensive, have long lead times, and are exceptionally heavy.
It is an object of the invention to provide a novel composite pole for supporting utility lines that has a tapered shape.
It is also an object of the invention to provide a novel composite pole for supporting utility lines that in lengths greater than 60 feet are lighter than wooden poles, steel poles or concrete poles.
It is another object of the invention to provide novel composite poles for supporting utility lines that would weigh less than 1000 pounds and thus allow them to be transported by light duty helicopters to remote installation sites.
It is an additional object of the invention to provide a novel composite pole for supporting utility lines that does not have any of the undesirable environmental objections such as are common with the use of timber poles.
It is a further object of the invention to provide a novel composite pole for supporting utility lines that is economical to manufacture and market.
SUMMARY OF THE INVENTION
The tubular tapered composite pole for supporting lines provides an alternative to wood poles in transmission class applications for new and replacement installations. There are several benefits from using poles formed from pultruded composite material. These type of poles would not use chemical preservatives such as wooden poles require, thus eliminating disposal and liability issues from the preservatives. Composite poles have an eighty year life and will not deteriorate in the environment and do not require preservatives to protect them from insects and the weather. The composite poles are resistant to pests such as woodpeckers and such other boring birds and insects. Also when the life span of a composite pole ends its inert material is recyclable. Much of the maintenance required for wooden poles would be eliminated by the use of composite poles. The composite poles are also much lighter than wooden poles making them much easier to transport and easier to install. This light weight feature makes them attractive versus steel and concrete also, resulting in much lower installation costs.
The novel tubular tapered composite pole is formed from a plurality of pultruded panels. These panels extend in length from 30-120 feet or longer. Since the dies used in the pultrusion process can only make panels having a constant width, it is necessary that certain machining operations be done to the initial panels that are formed. Preferably, the panels would have a groove structure formed along its length on one of the side edges of the panel. A biased cut would be made from the top edge of the panel to its bottom edge to form a trapezoidal shaped panel. An interlocking tongue structure would be machined on to the edge of the biased cut side edge of the panel, made at the same time as the biased cut using advanced CNC machinery. The combined tongue and groove structure that the inventor utilizes has been given the name of a fir tree joint. A plurality of the aforementioned panels are assembled together with their respective tongue interlocking structure captured in the respective groove structure of the adjacent panels. These interlocking structures may also have adhesive material applied to their surfaces. The resulting structure is a tapered elongated tubular composite pole for supporting utility lines. The diameter of these utility poles would be in the range of 16-40 inches at their base and 5-16 inches at their top.
The interlocking fir tree joint is an important feature of this invention. Composite materials can have the strength of steel, but have a modulus of elasticity that is {fraction (1/7)}th that of steel. This means the material can deflect under high load, but not yield or permanently change shape. This characteristic is advantageous to the successful manufacturing of a composite pole and the double snap groove configuration of the fir tree joint is a key feature. When assembling six panels of a composite pole using the fir tree joint, tremendous force is required to open up the entrance to the groove side of the joint. This is accomplished with a proprietary machine that applies inward pressure to each panel. Once the joint is completely interlocked, the manufacturer knows the assembly is complete due to a loud “snap”. The joint is thus held together with several thousand pounds of clamping force, equivalent to the several thousand pounds of force required to snap the joint together initially.
Once this fir tree is snapped together, the machining process is significantly complete. If adhesives are used in the joint the high pressure clamp force provides a dual feature. First by dimensioning the fir tree joint correctly, a fixed bond line (thickness) can be controlled. Any excess adhesive in the groove will be squeezed out of the joint and the optimum bond line for strength can be achieved. Secondly, the excessive clamping force of the assembled fir joint is absolutely mandatory for achieving a satisfactory bond joint. It is well known in adhesives that a clamp force is required to permit an acceptable cure. If it were not for the fir tree joint, bond pressure would need to be applied on the outside and inside of every inch of seam over the entire pole. With 30 minute cure adhesives (state-of-the-art) there is not time to put secondary clamps on the seams. There is no conceivable method to apply force on the inside of the pole with specialized tooling. An 80 foot pole is 960 inches in length. With 6 joints per pole this is 5760 lineal inches of seams. This means a mechanical tool would need to quickly clamp 5760 lineal inches on the outside of the pole and a second internal clamp would need to apply outward pressure to an additional 5760 inches of seam on the inside. This would have to be done within 30 minutes of assembling the pole. The fir tree joint eliminates this expensive tool requirement.
Finally, the fir tree joint assists with the prevention of slippage in the joint. An 80 foot pole without the clamp pressure assistance of the fir tree joint would slip and bend under its o
Friedman Carl D.
Logan II Charles C.
Wilkens Kevin D.
LandOfFree
Tubular tapered composite pole for supporting utility lines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tubular tapered composite pole for supporting utility lines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tubular tapered composite pole for supporting utility lines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2491512