METHOD AND PANEL FOR CONSTRUCTING COURT WALLS
WIPO Patent Application WO/
An improved method and panel for constructing racquetball and squash court walls in which the panel (10) is constructed with an ability to withstand wide fluctuations in humidity and temperature. This is accomplished by applying a phenolic plastic laminate or moisture resistant seal around the outer edges of an industrial particle board core (12) and then applying a wood style (14) around the outer edges of the phenolic plastic laminate covered edges of the industrial particle board core (12). The next step requires applying a sheet of plastic laminate (18) to both faces of the particle board core (12) overlapping the wood styles (14) thus encapsulating the particle board core so moisture cannot penetrate. The edges of the styles are conventionally routed and squared for tongue (20) and groove (22) installation.
Inventors:
Randall, Mattingly
Application Number:
Publication Date:
07/09/1992
Filing Date:
12/17/1990
Export Citation:
Randall, Mattingly
International Classes:
A63C19/00; E04C2/16; E04C2/38; E04H3/14; (IPC1-7): A63B71/02
View Patent Images:
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Foreign References:
34628974630418470205447083364741136
1. An improved panel for constructing racquetball and squash court walls which comprises a formed particle board core having a size slightly less than the finished panel, styles which are di ensionally stable secured to the surrounding edges of the particle board, opposite outer edges of the styles on opposing edges having a tongue and groove configuration, a sheet of phenolic plastic laminate secured to opposite surfaces of the particle board and which overlaps the style secured along each edge of the particle board, characterized in that a water resistant sealing means is disposed between abutting edges of the particle board and the style.
2. An improved panel as set forth in claim 1, in which the style is made of wood.
3. An improved panel as set forth in claim 3, in which the wood is catalpa or northern white cedar.
4. An improved panel as set forth in claim 1, in which the style is made of PVC.
5. An improved panel as set forth in claim 1, in which the style is made of calcium silicate.
6. An improved panel as set forth in claim 1, in which the water resistant sealing means is selected from a group consisting of waterproof paint, rubberized material, plastic sheet, plastic laminate, phenolic plastic, epoxy coating, phenolic kraft paper, or an adhesive coating.
7. A method of forming an improved panel for construction of a racquetball and squash court comprising the steps of: forming a particle board core which is of slightly less dimension than a finished panel,
forming a style of a dimensionally stable material for each edge of the particle board core, a respective style being of a longer dimension than a corresponding edge of the particle board, gluing the style to each edge of the particle board core, applying a glue to completely cover opposite side surfaces of the particle board core, applying a sheet of phenolic plastic laminate onto each side surface of the particle board core to overlap the styles secured to the edges of the particle board, machining the outer edges of the styles to the proper dimensions of a finished panel and to form a tongue and groove on opposing edges, applying a pressure onto the styles to secure the styles to the edges of the particle board, applying pressure onto said sheets of plastic laminate to insure adherence to the surfaces of the particle board and the styles, and applying a moisture resistant sealing material onto an edge of each of the styles before securing the edge to a corresponding edge of said particle board with the moisture resistant sealing material between outer edges of the particle board and inner edges of the styles.
8. A method as set forth in claim 7, in which the style is selected from a group consisting of wood, PVC or calcium silicate.
9. A method as set forth in claim 7, in which said moisture resistant sealing means is selected from a group consisting of phenolic kraft paper, waterproof paint, rubberized material, plastic sheet, plastic laminate, an epoxy coating or an adhesive coating.
10. An improved panel for constructing racquetball and squash court walls which comprises a formed particle board core having a size slightly less than the finished panel, styles secured to the surrounding edges of the particle board, outer edges of the styles on opposing
edges having a tongue and groove configuration, a sheet of phenolic plastic laminate secured to opposite surfaces of the particle board and which overlaps the styles secured along each edge of the particle board, characterized in that the style is comprised of a material which is dimensionally stable.
11. An improved panel as set forth in claim 10, in which the style is made of catalpa wood.
12. An improved panel as set forth in claim 10, in which the style is northern white cedar.
13. An improved panel as set forth in claim 10, in which the style is made of PVC.
14. An improved panel as set forth in claim 10, in which the style is made of calcium silicate.
15. A method of forming an improved panel for construction of a racquetball and squash court comprising the steps of: forming a particle board core which is of slightly less dimension than a finished panel, forming a style of a dimensionally stable material for each edge of the particle board core which is of a longer dimension than a corresponding edge of the particle board, gluing a style to each edge of the particle board core applying a glue to completely cover opposite side surfaces of the particle board core, applying a sheet of phenolic plastic laminate onto each side surface of the particle board core to overlap the styles secured to the edges of said particle board, machining the outer edges of the styles to the proper dimensions of a finished panel and to form a tongue and groove on opposing edges, applying a pressure onto the styles to secure the styles to the edges of the particle board, and
applying pressure onto the sheets of plastic laminate to insure adherence to the surfaces of the particle board and the styles.
16. A method as set forth in claim 15, in which said style is selected from a group consisting of wood, PVC or calcium silicate.
Description:
"METHOD AND PANEL FOR CONSTRUCTING COURT WALLS" TECHNICAL FIELD This invention is directed to a racquetball and squash court and more particularly to an improved racquetball and squash court wall panel construction which will withstand wide fluctuations in humidity and temperature. BACKGROUND ART A typical racquetball court has four vertical walls. The court dimensions are 40' long by 20' wide by 20' high. The sidewalls require 800 square feet of paneling or a combination of twenty-eight 4' x 8' and 4' x 4' panels. These panels are butted together with the edges either erfed for tongue and groove, lap joints, or aluminum spline. These processed edges allow the panels to be installed on studs or furring by use of screws with the screws embedded into the core of the panels so that when the next panel is slotted against the adjoining panel, the screws are covered up inside the panel. In addition to the screws, a bead of adhesive is applied on each furring strip or stud. The screws basically align the panels and hold the individual panels onto the studs or furring until the structural adhesive dries. The vast majority of racquetball and squash courts built in the USA over the past fifteen years have been 4' x 8' and 4' x 4' plastic laminate particle board panel systems. These interlocking panels consist of a high density particle board sandwiched between phenolic plastic laminate. They are constructed either with high pressure cold press methods or thermally fused mela ine applied directly to the particle board during the manufacturing process. In either process, there is basically a particle board core sandwiched between
phenolic plastic laminate. A popular method of constructing indoor courts is with standard plastic laminated particle board made into 4' x 8' and 4# x 4' panels with either interlocking tongue and groove seams or spline system. In today's racquetball and squash industry, there are two types of wall systems utilized. Most commonly used are 4' x 8' and 4' x 4' plastic laminated particle board panels which are installed over furring or steel studs. The older system, not used extensively, is a plaster or fiberglass reinforced concrete which is normally trowelled over steel mesh which is attached to concrete block walls. The typical problem associated with panel type courts involves maintaining their integrity in an environment beyond a range of 40% to 60% humidity. If not kept within these stringent tolerances, the panels will absorb moisture which will cause cupping at the seams. The courts must be installed in a controlled air environment and be kept in this constant humidity range for the life of the court. The HVAC system has to operating properly at all times to control the court humidity and temperature. Also, warpage of panels can occur if there are water leaks for instance pipes breaking or roofs leaking. Problems associated with wet wall or plaster courts are the constant cracking and peeling of the plaster type surfaces. These require continual patching and painting in order to keep the courts in reasonable condition. After several years, the wet wall systems always look old and worn which is undesirable, especially in clubs and college situations. Wet wall or plaster type courts are also extremely noisy which has contributed to their decline over the years. The advantages associated with utilizing a dry wall or panel type court are listed as follows: Basically, once installed and kept in a consistent humidity and
temperature environment, the courts are virtually maintenance free. Because the walls consist of plastic laminate, they are easily cleaned with kitchen type cleaning solutions. There is the additional benefit of consistent installation because the panels are premanufactured at a factory prior to shipping. Thus, they provide uniform ball rebound and play characteristics. One advantage of the wet wall or plaster system is that it is a very solid playing surface. Also, changes in humidity and temperature do not effect a wet wall system. It is well known that problems occur when these interlocking sports panels absorb moisture along the edges. This moisture is introduced either through rising humidity in the air or condensation occurring on one side of the panel, or actual water, as in the case of roof leaks or broken pipes. If one was only concerned about an individual panel expanding (for instance like a dinette table top or an individual door) then there would actually be no cause for concern. Because there are twenty-eight interlocking sports panels all joined together on a single wall, the expansion of each panel applies pressure to the others on all four sides. As moisture travels inside the particle board cores, swelling develops in both thickness and length of each individual panel. The damage is caused, however, by the cumulative action over the entire wall. Intense pressure builds up as the panels expand in length, height and thickness to the point where buckling must occur at the seams. In minor humidity fluctuations from 50% to 70%, slight cupping is readily apparent. If the problem is not resolved immediately, this warping will cause permanent damage. There have been cases where as much as one inch curvature of the edges of the panels due to excessive humidity has been recorded, which makes these courts totally unusable. Over the past fifteen years and thousands of courts later, the vast majority of
racquetball courts utilize this type of a 4' x 8' and 4' x 4' particle board panel. The problem is worldwide, and has never been solved. The problem has been controlled through the use of sophisticated HVAC systems, adequate insulation, and experience by the court installers within the industry. However, in many situations HVAC systems are not adequate, and insulation and building construction is not done properly. There are certain situations, such as in universities and colleges, in which courts are not used during the summer months and where building owners would like to reduce the HVAC operating costs within their facilities. Currently they are unable to do so because of the potential damage of warping panels due to excessive moisture if not maintained in a controlled atmosphere. In racquetball and squash courts previously built, problems occur when humidity fluctuates, — especially when it rises — and moisture is absorbed into the particle board core. Because the panels are installed over an 800 square foot wall with twenty-eight panels interconnecting along all edges, the wall acts as a single large panel. When moisture is absorbed, the wall expands until buckling occurs at each panel seam causing permanent damage at the panel seams. Buckling can occur with a humidity level of over 60%. If humidity levels drop significantly below 40%, then gaps become present along the edges of two abutting panels thereby becoming a visual hindrance. Prior patents have disclosed different types of wall construction which attempted to deal with the humidity fluctuation within the court, in particular the following known U.S. patents 3,405,493; 4,238,914; and 3,893,275 addressed this problem. These patents either required materials which are too expensive to be economically feasible, or the materials were not readily accepted within the sports industry. Other problems occurred with
these inventions when humidity fluctuation actually did cause the particle board subsurface to expand, causing cracks in the monolithic material trowelled over the particle board. Consequently, none of these systems have been accepted in the sports industry today. DISCLOSURE OF INVENTION In carrying out this invention, a standard 4' x 8' and 4' x 4' particle board panel, heretofore accepted for constructing racquetball and squash courts, has been constructed with an ability to withstand wide fluctuations in humidity and temperature. A standard particle board panel has been used onto which a specially selected wood style has been glued around its edges. This is accomplished in part by applying a wood style around industrial particle board in conjunction with the application of a special moisture resistant seal. Applying phenolic plastic laminate to both faces of the core overlapping the wood piece thus encapsulating the particle core so moisture can not penetrate to the particle board. The wood edges are conventionally routed and squared for tongue and groove installation. The moisture resistant seal consists of phenolic plastic laminate glued to the edge of the wood style which is next to the particle board edge. The wood style consists of a type of wood that resists expansion when moisture is absorbed. The key feature of this invention is that when moisture is absorbed in the panel, only the wood edges 1- 1/2" deep around the panel can expand because of the moisture resistant seal. When moisture is absorbed in the standard particle board core, the entire 4' x 8' panel can expand as moisture penetrates throughout the core. In high humidity, the style without the moisture resistant seal will perform adequately. In extreme humidity, the moisture resistant seal is recommended. Moisture can penetrate the wood style, especially when humidity exceeds 80%. This diffusion process will allow moisture to travel into the particle board core if the phenolic moisture resistant seal were not in place. In
less than 80% humidity, the moisture would be contained by the wood style and would not reach the particle board core with or without the phenolic moisture resistant seal. However, there are many instances when humidity exceeds 80% in a typical athletic type building. The moisture resistant seal also ensures integrity in the case of high moisture other than humidity - such as water leaks. Heretofore, because of high humidity, it has been necessary to form the particle board cores of Western Ponderosa Pine to restrict the absorption. With the present construction the cores may be made of less expensive Southern Pine. Further, in the prior art system of construction, it was required that the panels be sent to the construction site a few days before construction so that the panels may acclimate to the building humidity. Also, construction could not begin until after a HVAC system was installed and in use. It is therefore an object of this invention to solve the problems encountered by humidity in current racquetball and squash courts. Another object is to provide a method and panel system whereby standard 4' x 8' and 4' x 4' accepted racquetball and squash panels are constructed such that they have an ability to withstand wide fluctuations in humidity and temperatur . Still another object is to provide a racquetball and squash court which has a neat appearance and one which will retain its neat appearance over a long period. Still another object is to provide a racquetball and squash court which does not require a HVAC system to protect the panel construction against absorption of dampness due to the humidity.
Yet another object is to provide a racquetball and squash court construction such that the panels are protected by a moisture resistant seal. While another object is to provide a wall panel construction for a racquetball and squash court which can be installed without the requirement for a prior construction of a HVAC system. Another object is to provide a panel system for a racquetball and squash court wherein less expensive material may be used for the panels. Another object is to provide a panel construction system such that the panels need not be shipped to the job site before actual construction starts. The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawings. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 illustrates a particle board made in accordance with this invention with portions removed to e Fig. 2 is an enlarged cross sectional view along 2-2 of Fig. 1 cut through the core material to Fig. 3 illustrates a side wall elevation of a racquetball or squash court made with panels accordi and Fig. 4 illustrates a partial view of a side wall and front wall with a structure to which the panels are secured. Fig. 5 is a partial cross sectional view through Fig. 4 along lines 5-5 illustrating the panels secured to the supports.
BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawing, there is shown in Figure 1 a particle board panel, with portions removed made in accordance with this invention. As set forth previously, finished panels are both 4' x 8' and 4' x 4'. In order to construct a panel 10 according to the invention, one must begin with a particle board core 12 which may be made of Southern pine having the dimension of about 46 1/2" by 94 1/2". The thickness of the core may vary between 1", 3/4" or 1/2" to provide a finished thickness of 1 1/8" for a front wall, 7/8" for a side and back wall and 5/8" for the ceiling. The core material 12 consists of a standard 45 lb. or 60 lb. industrial grade particle board. Before construction of the panel, the moisture content of the core material should be 5% ± 1%. Wood strips 14 are made of catalpa wood or northern white cedar installed around the edges of the particle board core. These wood strips are selected for this purpose because of their resistance to expansion, once moisture has been introduced, as will be explained in greater detail in later paragraphs. The wood strips should be cut to approximately 1 1/2" wide and by the proper length depending on whether the finished size is 4' x 4' or 4' x 8' long and depending on which edge of the core the strips are to be applied. Before application of the wood strips to the core, a phenolic laminate or moisture resistant seal 16 needs to be applied to the edge of the wood strip that is to be installed against the particle board core or to the edge of the particle board core. The thickness of the laminate is typically 0.050 phenolic plastic laminate supplied by companies like Formica Corporation. The phenolic moisture resistant seal can be edge-banded to the wood strip using a typical hot melt process. This process laminates the phenolic strip to the edge of the wood strip and trims it flush to both sides of the wood strip at the same time.
Once the phenolic strips are installed on the edges of the wood strips, these now edge-laminated styles can be glued and clamped on all four surrounding edges of the particle board core. The phenolic edge must be in contact with the particle board core. These strips are glued onto the particle board core using a contact glue. Clamps are applied until the glue dries. Once the drying process is complete, the clamps are removed and panels with the wood strip styles installed thereon are then run through a double-sided abrasive planer to sand smooth all wood to the same plane. After sanding, the panels are run through a Black Brothers Glue Spreader applying urea formaldehyde glue approximately five to seven mils thick on both sides of the core and wood strips. After applying glue to both faces of the panels, a sheet of plastic laminate 18 is then applied to both faces of the panel . The panels are stacked and moved into a hydraulic press. The panels will stay pressed under 60 lbs. per square inch pressure for approximately one hour. After removal from the press, all four edges will be machined through the double end tennenor. This machine trims the edges, adding the tongue 20 and groove 22 and squaring the panel to ± 1/32". After the edges are routed, the finished panel has approximately 1" of wood strip around all edges so that moisture must travel through the wood strip before reaching the phenolic moisture resistant seal. Because of the special moisture resistant seal, moisture would not be able to penetrate to the porous particle board core. This is one key in the development of this new panel. After manufacturing the panels, the materials (including the panels) are shipped to the appropriate job sites for installation. A typical wall installation incorporates 800 square feet or an area of 40' long x 20' high illustrated by Fig. 3. There are twenty-eight interlocking panels that are glued and screwed 28 to
steel studs 24 or furring strips, see Fig. 4. Each panel is glued to these studs with a structural panel adhesive. The fasteners are screwed through the tongues into the studs with a self-countersinking head. The next panel is slotted into the joining panel thus causing the screw heads to be embedded inside the panel along the seams. Once installed, no screws or glue are visible from the playing side. Fig. 4 illustrates the steel wall support structure. It is obvious that in order to have straight end walls, some of the panels must be made in 4' x 4' dimensions in order to set the panels alternating in adjacent rows and to have a smooth edge on opposite ends of the wall. In consideration of the type of wood to be used for the styles, the following woods were analyzed: Poplar, northern white cedar , red oak, catalpa, cherry, teak, mahogany, and maple. Among this group, the catalpa and northern white cedar stood out as having the most resistance to movement or expansion once some moisture is introduced. All samples were subjected to numerous types of humidity tests with and without various types of wood sealers. The catalpa and northern white cedar were found to be the most acceptable for the new panels. Over a five day 100% humidity test, the thickness swell of the catalpa was .006 inches, while the northern white cedar was .019 inches. If one were to compare this thickness swell .with normal racquetball panel construction of 45 lb. particle board core, the thickness swell under the same conditions would be 0.1875 inches. In other words, the particle board expanded over thirty times greater than the catalpa wood during the same test. Even though this is true, it is even more significant that the moisture, if it does penetrate the wood strip, can only effect the first 1 1/2 " because of the phenolic moisture resistant seal. However, once moisture is introduced into a standard particle board panel, it can travel throughout the entire eight foot panel very rapidly.
It has been determined that completed panels using standard, prior art procedures, subjected to extreme humidity will continue to expand or move until permanent damage occurs on the racquetball court walls. However, the panel of this invention withstands this high humidity with little or no damaging effect. Experiments were also conducted using several types of wood sealers with all of the types of wood listed above. These sealers will reduce slightly the moisture absorption in the catalpa and northern white cedar once humidity is introduced. There are several sealers that will perform equally. For instance, Sher-wood Homoclad Sealer by Sherwin Williams is a synthetic sealer that may be used. As a contrast, if one coats the edges of the particle board with these sealers, there seems to be no noticeable resistance to moisture. This is primarily because of the open pores within the particle board core. Also, the particle board is made from a softwood. The catalpa and northern white cedar styles are hardwood. It is also worthy of mention that a hydrous calcium silicate has been tried in place of the catalpa wood and northern white cedar wood style. This product performed adequately in the test and could be used as a substitute style, but only if the moisture resistant seal is applied to the edges of the calcium silicate. Also, a plastic style of PVC can also be substituted. This proved acceptable once installed, as it kept all moisture from reaching the particle board core and did require the use of a moisture resistant seal. The cost of installing a plastic style in lieu of the wood style was significantly greater. The new panel has the following advantages: 1. This new panel has many features, one of which is that each panel will be able to resist expansion due to humidity fluctuations within the environment. No longer will this moisture absorption occur, thereby eliminating
very costly damage to the racquetball and squash court walls. 2. Because each panel has the ability to resist moisture absorption, the entire wall will not move as one unit. This is currently not the case with standard panels. All of the prior art panels expand together as a unit applying pressure upon each other which causes cupping and warping at the seams. In the new panel, only the outer 11/2" could be effected by moisture. The expansion of the wood style is not enough to cause damage to the panel. Even if moisture travels through the wood style, the phenolic moisture resistant seal will stop moisture from entering the particle board core. 3. The new wall system can be installed in a non- controlled environment. Currently, the typical wall panels must be installed in a controlled environment of 40% to 60% humidity and 65 to 78 degrees. These new panels can be installed within a 10% to 90% humidity level with 40 to 95 degree temperatures. This means that the courts can be installed prior to the operation of an HVAC system and therefore does not delay the project. Currently, there are situations in which the air conditioning units cannot be turned on until the building is finished, and the wall system cannot be installed until the air conditioning is turned on. This new panel solves this major problem. Many times the buildings do not have the proper amount of insulation or have the wrong HVAC systems, which usually shows up during the high humidity season and results in damaged panels. Also, these new panels will be very useful overseas where proper building construction and HVAC systems are not as efficient as they are in the USA. Many courts installed overseas are experiencing warping due to moisture absorption which this new panel will solve. 4. Currently, once the standard racquetball panel is installed, the HVAC system must operate for the life of the court system. This means that 365 days a year, the system must be operating in order to control the humidity level within the court. Once installed, these new panels
will enable the operators to regulate the HVAC system and maximize their cost savings. For instance, colleges that have classes nine months a year normally leave their systems operating during this time. However, when school is closed and they wish to turn the air conditioning off within the court system, this new panel will enable them to do so. This will save a tremendous amount of money for utilities and wear on the HVAC equipment. With the new panels, air conditioning is operated mainly for the benefit of the players, not to control humidity for the walls. 5. In a current typical particle board plastic laminate panel, the core is a Western Ponderosa Pine. A less expensive Southern Pine is not used in the core because of its tendency to absorb moisture quicker than its Western counterpart. However, with the wood styles installed along the edges with the moisture resistant seal, the chance for the core to absorb moisture no longer exists. Therefore, in the new panel, one can recommend using a Southern Pine particle board core which will save substantial money over using the Western Ponderosa Pine. 6. Currently, materials are shipped to the job site several days prior to installation so that they may acclimate to the building humidity. This is costly because many times the installation crews must make two trips, one to receive and unload the materials and a second to install the materials a week or two later once the materials have acclimated to the building humidity. Many times a job must be stopped just prior to installation or during installation because of improper humidity within the building. This causes the tongue and groove around the edges of the panels to swell so that it is difficult to fit them together. This new panel solves this problem totally, and will allow the crews to make only one trip just prior to installation. There would never be a reason to leave the job site because of excessive humidity in the building.
7. One important feature of this invention is that it incorporates standard, accepted racquetball and squash court panel materials that are currently being marketed today. Over 90% of all courts built world wide today use a plastic laminated particle board panel. It is important that any new panel use materials in accordance with the present invention. 8. Currently there are thousands of old plaster courts in need of renovation. These courts are being used in deteriorated condition. The plaster has been cracked or is pitted and they are unable to be fixed with additional plaster. Many of these courts are simply abandoned because they are unable to be repaired. Many plaster courts are repaired with a new lining of racquetball panels which are installed over furring strips. This is the typical way to fix a deteriorated plaster court. However, many of these courts are built with inadequate HVAC systems and insulation. Therefore, installing a traditional racquetball panel would not work because of the lack of humidity controls. This new panel could be incorporated inside of these plaster courts on furring strips and make them usable once again. 9. An important part of this invention is the dual aspects in which the panel can be constructed. If, prior to the installation of the new panel in a building, the humidity is known not to exceed the parameters of 30% to 80%, then the phenolic moisture resistant seal could be used but is not required. If however, the humidity could exceed these parameters to a maximum limit of 10% to 90% humidity level, then it would require the phenolic moisture resistant seal. Not incorporating the phenolic moisture resistant seal within the panel would save mo however, incorporating the phenolic moisture resistant seal would insure a panel that would not expand in high humidity situations.
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