1. Field
The present disclosure relates to swimming pool covers, and, more particularly, to a method and apparatus for attaching webbing to the edges of pool covers.
2. Background
Swimming pools are commonly covered to prevent debris from entering the pool, to preserve chemical treatments in the water and to heat the pool in the case of a solar cover. Typically, a pool cover will extend over the entire surface of the pool during periods of non-use and then be retracted during periods of use. The cover may be extended and retracted by mechanical or automatic means. In either case, a track assembly is usually connected to or built into the walls for guiding the edges of the cover as it traverses the pool. The pool cover typically has some means connected along the edge of the cover interacting with the track assembly to facilitate movement of the pool cover.
The pool cover may be fabricated from a vinyl-coated mesh made up of a dacron thread or “skrim” covered on top and bottom by vinyl coating. The result is a strong, durable and waterproof material that is ideal for long-term, maintenance-free use. The webbing may be made out of canvas or sail cloth, so that it can endure the mechanical stresses and wear placed on it as the bead slides along the tracking assembly and as weight is placed on the cover.
The webbing may be connected to the pool cover by thread stitches running along the webbing. Although the stitches are made of strong and durable thread, they are vulnerable to wear and may eventually wear out before the cover or the webbing. This wear occurs as the result of several factors, including ultraviolet rays from sunlight, chemical corrosion from pool chemicals and the mechanical stresses described above. Accordingly, it is not unusual for periodic repairs to be required to the thread stitching in order to maintain the integrity of the connection between the webbing and the pool cover.
Accordingly, there is an important need for an improved connection between the pool cover and the webbing that forms the edge bead for the pool cover. An improved webbing material and method of attaching the material to the pool cover is needed to reduce maintenance on the pool cover and to increase safety and durability for the pool cover.
The present disclosure provides an improved method for attaching border webbing to an edge of the pool cover to form a bead for guiding the webbing along an encapsulated track. The border webbing is heat sealed to the edge of the pool cover to form a durable attachment thereto. The webbing and the edge of the pool cover are made of heat sensitive material that become plastic and form a bond with the application of heat.
One application of the disclosure comprises a method for attaching an elongated webbing member to an edge of a pool cover, wherein the edge of the pool cover is positioned so that a portion of the pool cover edge is in contact with a portion of the webbing. The portion of the pool cover edge is then heat sealed to the portion of the webbing.
The method further comprises wrapping the webbing around an elongated filler member, so that at least one flap extends from the filler member, positioning the portion of the pool cover edge to overlap the flap, and applying heat to cause a heat seal between the portion of the pool cover edge and the flap. Preferably, the portion of the pool cover edge and/or the flap are composed of a heat sensitive material that will form the heat seal.
Another application comprises a pool cover having at least one pool cover edge, a webbing coupled to at least a portion of the pool cover edge by a heat seal between a portion of the webbing and a portion of the pool cover edge.
Additionally, the portion of the webbing and/or the portion of the pool cover edge may be made of a thermoactive material, such as vinyl, that becomes plastic with the application of heat, to form the heat seal. As used herein, the term “thermoactive material” means a material that is sufficiently sensitive to heat to become pliable or plastic in consistency, so as to provide a surface appropriate for heat welding. The webbing may be wrapped around a filler element to form a bead, so that the bead substantially maintains its shape under mechanical stress to guide the edge of the pool cover along a mechanical track.
Another implementation includes an apparatus for forming a webbing attached to the edge of a pool cover, comprising a positioning element for disposing a portion of the webbing in contact with a portion of the pool cover edge and a heating element for applying heat to form a heat seal between the webbing portion and the pool cover edge portion.
Additional optional features include a pressing element for consolidating the heat seal between the webbing portion and the pool edge cover portion. The positioning element may provide a flap extending from the webbing to overlap the portion of the pool cover edge and form the heat seal therewith. The apparatus may further comprise an element for wrapping the webbing around an elongated filler element, wherein the wrapping element forms the portion of the webbing to include at least one flap extending from the filler element. The portion of the pool cover edge may extend between first and second flaps of the webbing. The heating element may include a first nozzle to apply heat to the first flap and a second nozzle to apply heat to the second flap.
The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure will be better understood by reference to the following description of an example taken in conjunction with the accompanying drawings, wherein:
FIGS. 5 A-C are schematic views showing the steps involved in fabricating a webbing structure;
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one example, in one form, and such exemplification is not to be construed as limiting the scope of the disclosure in any manner.
In
In
In
As previously mentioned, the pool cover 16 may be fabricated from a vinyl-coated mesh made up of a dacron thread or “skrim” covered on top and bottom by vinyl coating. The result is a strong, durable and waterproof material that is ideal for long-term, maintenance-free use. The webbing may be made out of canvas or sail cloth, so that it can endure the mechanical stresses and wear placed on it as the bead 36 slides along the encapsulation assembly 30 and as weight is placed on the cover 16.
The thread stitches 45 and 46 or 42 and 44 are vulnerable to extensive wear. Although very strong and durable thread is used and multiple stitch lines are applied, the thread may eventually wear out before the cover or the webbing. This wear occurs as the result of several factors, including ultraviolet rays from sunlight, chemical corrosion from pool chemicals and the mechanical stresses described above. Accordingly, it is not unusual for periodic repairs to be required to the thread stitching in order to maintain the integrity of the connection between the webbing and the pool cover.
Looking now at FIGS. 5A-C, a preferred application of the method of the present disclosure is shown. As shown in
As shown in
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One advantage to the implementation disclosed in
Looking particularly at
The hot air generated by heater elements 76 and 82 may be heated to a temperature of between approximately 1000-1300 degrees Fahrenheit. Fifty pounds or more of pressure may be applied by the rollers 72 and 74 to the heated flaps 57 and 58. The result is an extremely strong heat weld or seam in the heat sealed web element 55 than will withstand forces that might be expected to be applied to the pool cover 50. The heat seal is not susceptible to deterioration from the sunlight or from chemical erosion. Methods of constructing such an apparatus are well known to those of skill in the art.
Moreover, the heat sealed web structure 55 above and below the pool cover edge 51, as described above, is formed in one pass of the materials through the apparatus. Heat is applied to the webbing flaps 57 and 58 at substantially the same time, and the rollers 72 and 82 confirm the heat seals to complete the sealing operation. This one pass procedure minimizes the amount of labor required to form the heat sealed webbing.
In operation, an operator may feed the webbing member 55 and the pool cover 50 to mate with each other, as further shown in
Referring now to
An substantially identical operation occurs on the underside of apparatus 70. Although not shown, heater element 82 and nozzle 84, seen in
It is understood that variations of the above preferred implementation might be employed within the scope of the disclosure. For example, in some cases the hot air coming from nozzle foot 80 and nozzle foot 86 may provide too much heat to the flaps 57 and 58 and the pool cover edge 51. In such case the upper or lower mechanisms may be offset by a a sufficient distance (not shown) to allow cooling of the flaps 57 and 58 and pool cover edge 51 between applications of hot air from the nozzle feet 80 and 86.
Thus, the upper mechanisms, including roller 72, heater element 76, nozzle 78 and nozzle foot 80 might be offset longitudinally along the service line of the pool cover edge 51 by some distance from the lower roller 76, heater element 82, nozzle 84 and nozzle foot 86. In the interim space, cool air may be applied to the flaps 57 and 58 and the pool cover edge 51 to allow the bond between the lower flap 58 and the pool cover edge 51 to cool and bond. Conversely, the hot air could be applied first to the upper flap and pool cover edge 51 and then the lower flap 58 and pool cover edge 51 could be bonded further down the service line of the pool cover edge.
Although the above applications are representative of the present disclosure, other applications will be apparent to those skilled in the art from a consideration of this specification and the appended claims, or from a practice of the applications of the disclosure. It is intended that the specification and applications therein be considered as exemplary only, with the present disclosure being defined by the claims and their equivalents.
This application is a divisional of U.S. patent application Ser. No. 10/305,467, filed Nov. 26, 2002, and entitled “Heat Sealed Webbing Method and Apparatus for Pool Covers”, by Lanny R. Smith, which claims priority under 35 U.S.C. 119(e) to provisional patent application No. 60/334,094, filed Nov. 29, 2001, the contents of which are hereby incorporated by reference.
Number | Date | Country | |
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60334094 | Nov 2001 | US |
Number | Date | Country | |
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Parent | 10305467 | Nov 2002 | US |
Child | 11274380 | Nov 2005 | US |