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Patent Searching and Data


Title:
POSITIVE DRIVE COVER SYSTEM
Document Type and Number:
WIPO Patent Application WO/2005/118983
Kind Code:
A1
Abstract:
A cover system (10) is provided to cover an opening of a space. A cover (12) is moveable between an open position and a closed position. Bead members (38, 40) are attached along the length of each side edge of the cover. Guide tracks (14) are positioned proximate the space to be covered and are configured to slideably receive and guide the plurality of bead members along the track length. Positive drives (18, 20) are configured to move the bead members into and out of the guide track to urge the cover between the open and closed position. A shaft is operably connected to the positive drives and a drive means for operating the cover system. Clutch means (140) is connected to the shaft to effect a driving relationship between the positive drives while allowing relative movement between the positive drives upon development of torsional forces of preselected magnitude.

Inventors:
RAGSDALE KELLY J
DRECHSEL LAMONT
BRADY CORY
Application Number:
PCT/US2004/017035
Publication Date:
December 15, 2005
Filing Date:
May 28, 2004
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
COVER POOLS INC (US)
International Classes:
A47H1/00; E04H4/00; E04H4/10; (IPC1-7): E04H4/00; A47H1/00
Foreign References:
US5701613A1997-12-30
US2754900A1956-07-17
Attorney, Agent or Firm:
Lillywhite, Jeffery M. (Suite 1800 299 South Main Stree, Salt Lake City UT, US)
Download PDF:
Claims:
What is claimed is:
1. A cover system comprising: a cover shaped and sized for positioning over an opening of a space to be covered, said cover being moveable between a closed position in which said cover extends at least in part over the opening and an open position in which said cover is displaced from said closed position, said cover having a first side edge and a second side edge spaced from said first side edge, said first side edge having a first edge length and said second side edge having a second edge length; a first plurality of bead members attached to said first side edge along said first edge length; a second plurality of bead members attached to said second side edge along said second edge length; a first guide track positioned proximate said space to be covered, said first guide track having a first track length, said first guide track being configured to slideably receive and guide said first plurality of bead members along said first track length upon movement of said cover between said open position and said closed position; a second guide track positioned proximate said space to be covered and spaced from said first guide track, said second guide track having a second track length, said second guide track being configured to guide said second plurality of bead members along said second track length; a first positive drive configured to move bead members of said first plurality of bead members into and out of said first track to urge said cover between said open position and said closed position; a second positive drive configured to move bead members of said first plurality of bead members into and out of said second track to urge said cover between said open position and said closed position; a shaft operably connected to said first and second positive drives; drive means operably connected to said shaft for operating said first and second positive drives; and clutch means connected to said shaft to effect a driving relationship between said first positive drive and said second positive drive while allowing relative movement between said first positive drive and said second positive drive upon development of torsional forces of preselected magnitude.
2. The cover system of claim 1 wherein said clutch means is disposed in said shaft between said first and second positive drives.
3. The cover system of claim 1 wherein said shaft has a first length and a second length, and wherein said clutch means effects said driving relationship between said first length and said second length.
4. The cover system of claim 3 wherein said clutch means includes a first coupling assembly attached to one end of said first length and a second coupling assembly attached to one end of said second length, said first coupling assembly being joinab Ie to said second coupling assembly.
5. The cover system of claim 1 wherein said clutch means is coupled to at least one of said first and second positive drives.
6. The cover system of claim 1 wherein said clutch means includes a first clutch assembly coupled to said first positive drive and a second clutch assembly coupled to said second positive drive.
7. The cover system of claim 1 wherein said clutch means includes a first portion and a second portion, said clutch means being configured to hold said first portion relative to said second portion to effect a mechanical relationship therebetween to transfer rotational torque between said first portion and said second portion while in operation, and to effect relative movement between said first portion and said second portion when said rotational torque exceeds a predetermined limit.
8. The cover system of claim 7 wherein said first portion is coupled to said first positive drive and said second portion is coupled to said second positive drive.
9. A cover system comprising: a cover shaped and sized for positioning over an opening, said cover being moveable between a closed position in which said cover covers the opening at least in part and an open position in which said cover is displaced from said closed position, said cover having opposite side edges; a plurality of bead members attached along each of said opposite side edges; guide tracks each positioned on at least two opposing sides of said space to be covered, said guide tracks being configured to slideably receive and guide said plurality of bead members; positive drives each positioned relative to each of said guide tracks and configured to move each of said plurality of bead members into and out of a respective one of said guide tracks to urge said cover between said open position and said closed position; a shaft operably connected to each of said positive drives; a drive mechanism operably connected to said shaft for operating said positive drives; and clutch mechanism connected to said shaft to allow relative movement between said the positive drives when the rotational torque between the positive drives exceeds a preselected value.
10. The cover system of claim 9 wherein said clutch means is disposed in said shaft between said first and second positive drives.
11. The cover system of claim 9 wherein said clutch means is coupled to at least one of said first and second positive drives.
12. The cover system of claim 9 wherein said clutch means includes a first clutch assembly coupled to said first positive drive and a second clutch assembly coupled to said second positive drive.
13. The cover system of claim 9 wherein said shaft has a first length and a second length, and wherein said clutch means effects a driving relationship between said first length and said second length.
14. The cover system of claim 13 wherein said clutch means includes a first coupling assembly attached to one end of said first length and a second coupling assembly attached to one end of said second length, said first coupling assembly being joinable to said second coupling assembly.
15. The cover system of claim 9 wherein said clutch means includes a first portion and a second portion, said clutch means being configured to position said first portion relative to said second portion to effect a mechanical relationship therebetween to transfer rotational torque between said first portion and said second portion while in operation, and to effect relative movement between said first portion and said second portion when said rotational torque exceeds a predetermined limit.
16. The cover system of claim 9 further comprising a receiver mechanism positioned relative to said positive drive for receiving said cover from and supplying said cover to said positive drive as said cover is moved between said open position and said closed position.
17. The cover system of claim 16, wherein said receiver mechanism comprises a space having a depth and wherein said receiver mechanism is positioned below said positive drive.
18. The cover system of claim 16, wherein said receiver mechanism comprises a takeup drum connected to said positive drive by a drive mechanism for driving said drum relative to the speed of said positive drive.
19. The cover system of claim 9 wherein said positive drive includes a bead sprocket having a circumferential wall with a plurality of inverse teeth formed there through, each of said plurality of inverse teeth being sized and configured to engage at least a portion of each of said plurality of guide beads.
20. A cover system comprising: a cover shaped and sized for positioning over an opening, said cover being moveable between a closed position in which said cover covers the opening at least in part and an open position in which said cover is displaced from said closed position, said cover having opposite side edges; a plurality of bead members attached along each of said opposite side edges; guide tracks each positioned on at least two opposing sides of said space to be covered, said guide tracks being configured to slideably receive and guide said plurality of bead members; positive drives each positioned relative to each of said guide tracks and configured to move each of said plurality of bead members into and out of a respective one of said guide tracks to urge said cover between said open position and said closed position; a shaft operably connected to each of said positive drives, the shaft having a first length and a second length; a drive mechanism operably connected to said shaft for operating said positive drives; and a clutch mechanism connected to said shaft, the clutch mechanism including a first portion and a second portion, said first portion including grooves on an outer surface of said first portion, said second portion including a spring plunger, wherein said first portion is arranged with respect to said second portion to position at least a portion of said spring plunger in one of said grooves to force said first and second lengths of said shaft to rotate until a torsional force becomes greater than a preselected magnitude wherein the first portion slips with respect to the second portion causing said spring portion to advance to another one of said grooves.
Description:
POSITIVE DRIVE COVER SYSTEM

BACKGROUND OF THE INVENTION

The Field of the Invention

[0001] The invention relates to systems for retractably positioning a cover over an opening of a space and, more particularly, to systems for retractably positioning a cover over a swimming pool.

State of the Art

[0002] The use of automated swimming pool covers on conventional residential- type swimming pools is well known. Examples of such are described in U.S. Pat. No. 5,913,613 to Ragsdale et al. ("the '613 Patent) and U.S. Pat. No. 5,920,922 to Ragsdale et al. ("the '922 Patent"). As discussed in the foregoing references, pool covers are becoming standard equipment for enhancing pool safety as well as reducing unwanted debris from entering the swimming pool when the pool is not in use and covered. In addition, the use of pool covers reduces heat loss from heated pool water and can also be used to heat the pool water during daylight hours by absorbing energy from the sun.

[0003] Many motorized pool cover systems include a recessed well or a raised housing positioned at one end of the pool. Mounted in the well or housing is an elongated drum fixed to a rotatable shaft which in turn is connected to an electric drive motor. A flexible pool cover is secured, at one of its ends, to the cover- collecting drum and is collectable thereon by rotational movement of the drum. The pool cover is extended over the top of the swimming pool by attaching draw cords to the opposite sides of the pool cover as longitudinal extensions thereof. The draw cords extend through track in which the edges of the cover slide. The draw cords extend the length of the pool and around a pulley rotatably fixed to the outermost end of their respective tracks. Typically, the draw cord is returned and secured to a collecting reel which is rotatably carried on the same elongated shaft that carries the cover-collecting drum.

[0004] In some versions, one collecting reel is carried on one side of the drum and the other is carried on the other side. In other versions, both reels are positioned next to each other with pulleys positioned to direct the draw cords to the appropriate reel. A coupling and dog clutch drivingly engage to drive the reels or the drum through the shaft. The dog clutch operates as illustrated and described in U.S. Pat. No. 4,858,253 to Lamb, the disclosure of which is hereby incorporated by reference.

[0005] The prior art systems, although effective for the purposes designed, on occasion damage the pool cover fabric during the time it is being retracted on the collecting drum. Tearing or ripping of the cover fabric can occur when one side of the cover fabric is collected on the drum at a rate faster than the other side. Eventually, the cover fabric is damaged. Systems to avoid this problem and to avoid costly repairs of the pool cover fabric are not known. BRIEF SUMMARY OF THE INVENTION

[0006] A cover system is provided including a cover shaped and sized for positioning over an opening. The cover is moveable between a closed position in which the cover substantially covers the opening and an open position in which the cover is displaced from the closed position. A plurality of bead members attach along each of the side edges of the cover. A guide track is positioned on at least two opposing sides of the space to be covered. The guide track is configured to slideably receive and guide the plurality of bead members along the guide track. A positive drive is configured to move each of the plurality of bead members into and out of the guide track to urge the cover between the open position and the closed position. A shaft operably connected to the positive drive between the plurality of bead members. A drive mechanism operably connected to the shaft for operating the positive drive. Clutch means is connected to the shaft to effect a driving relationship between the first positive drive and the second positive drive while allowing relative movement between the first positive drive and the second positive drive upon development of torsional forces of preselected magnitude.

[0007] hi other embodiments of the present invention additional components can be provided. For example, the shaft of the cover system can be provided with two parts and the clutch mechanism couples the two parts of the shaft. The clutch mechanism can include a coupling assembly for each end of the shaft. Also, the clutch mechanism can be provided between the positive drive at a midpoint between the plurality of bead members attached along each of the side edges. The clutch mechanism may alternatively or in conjunction be coupled to the positive drive. The cover system can provide a clutch mechanism that includes a first and second portion, the first portion being held within the second portion by frictional force to distribute rotational torque while in operation, and when the rotational torque exceeds a predetermined limit, the first portion being allowed to rotate within the second portion. [0008] The cover system can also include a receiver mechanism positioned relative to the positive drive for receiving the cover from and supplying the cover to the positive drive as the cover is moved between the open position and the closed position. The receiver mechanism can include a space having a depth and wherein the receiver mechanism is positioned below the positive drive. The receiver mechanism can also include a take-up drum connected to the positive drive by a pulley and belt arrangement.

[0009] In the present invention, the cover system can provide a positive drive that includes a bead sprocket having a circumferential wall with a plurality of inverse teeth formed there through, each of the plurality of inverse teeth being sized and configured to engage at least a portion of each of the plurality of guide beads. The drive mechanism can include a first electric motor or a first hydraulic drive mechanism connected to the shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0011] FIG. 1 is a perspective view of an enclosure system of the present invention;

[0012] FIG. 2 is a cross sectional view of the enclosure system illustrated in FIG. 1;

[0013] FIG. 3 A is a partial view of an edge of the pool cover illustrating a plurality of edge beads disposed thereon;

[0014] FIG. 3B is a close-up view of an edge bead in a guide track;

[0015] FIG. 4 is a partial cross sectional depiction of an edge bead secured to the cover taken along the line 4 - 4 as shown in FIG. 3 A;

[0016] FIG. 5 A is a cross sectional view of a guide track taken along the line 5 A - 5 A as shown in FIG. 1 ;

[0017] FIG. 5B is a cross sectional view of an alternative construction for a guide track of the present invention;

[0018] FIG. 6 is an exploded view of a positive drive mechanism shown in FIG. 1; [0019] FIG. 7 A is an overhead view of an enclosure system of the present invention showing a single drive means with a drive shaft disposed between the positive drive mechanisms;

[0020] FIG. 7B is an overhead view of an enclosure system of the present invention showing a drive means attached to each of the positive drive mechanisms;

[0021] FIG. 8 is an exploded view of an enclosure system of the present invention showing a first embodiment of a clutch;

[0022] FIG. 9 is a perspective view of the enclosure system illustrated in FIG. 8 in an assembled state;

[0023] FIG. 10 is an exploded view of the enclosure system illustrated in FIG. 8 showing the clutch from another side;

[0024] FIG. 11 is a perspective view of the enclosure system illustrated in FIG. 10 in an assembled state;

[0025] FIG. 12 is an exploded view of an enclosure system of the present invention showing a second embodiment of a clutch;

[0026] FIG. 13 is a perspective view of the enclosure system illustrated in FIG. 12 in an assembled state;

[0027] FIG. 14 is an exploded view of the enclosure system illustrated in FIG. 12 showing the clutch from another side; and

[0028] FIG. 15 is a perspective view of the enclosure system illustrated in FIG. 14 in an assembled state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The various exemplary embodiments provide systems for retractably positioning a cover over an opening of a space.

[0030] Referring to FIG. 1, an enclosure system 10 generally includes a cover 12, a first guide track 14, a second guide track 16, a first positive drive 18, a second positive drive 20 and a drive means 22. The enclosure system 10 retractably positions the cover 12 over an opening of a space to be enclosed, such as, for example, a swimming pool 24. The enclosure system 10 operates by driving the cover 12 between an open or retracted position and a closed position. In the open position, the opening of the space to be enclosed is uncovered sufficient for the space to be accessible and useable. Preferably, the opening is substantially uncovered in the open position. The cover is substantially uncovered when the opening is more uncovered than covered. That is, it can be greater than about 50% uncovered to about 100% uncovered. In the closed position, the opening of the space to be enclosed is substantially covered. That is, the space is covered sufficient for the space to be more covered than uncovered. In particular, it can be covered from about 50% to about 100%. Use of the terms "substantially covered" and "substantially uncovered" herein indicates that the opening of the space to be enclosed need not be completely covered or uncovered by the enclosure system 10.

[0031] The swimming pool 24 illustrated in FIG. 1 represents a wide variety of swimming pool and other configurations that exhibit a space to be enclosed. For example, the enclosure system 10 described herein can be made to work equally well for swimming pools that are oval in shape, or that are elliptical or kidney shaped. With swimming pools that are oval in shape, for example, the first and second guide tracks 14, 16, although positioned parallel to one another, will not necessarily be in alignment with any particular wall of the swimming pool. Further, the enclosure system 10 can be used for ponds, recessed spas, and tiered or terraced pools. Still further, the enclosure system 10 described herein can be configured to enclose a wide range of shaped openings or spaces that benefit from periodic covering and uncovering.

[0032] Referring to FIGS. 1 and 2, the swimming pool 24 is illustrated as including a first side wall 26, a second side wall 28, a front wall 30, which is the wall opposite the positive drives 18, 20, and a rear wall 31. The swimming pool 24 also has a deck or surface 32 that surrounds the four walls of the pool. The shape and dimensions of the deck or surface 32 are not critical, but the deck or surface 32 must nonetheless provide a stable structure from which to secure the first and second guide tracks 14, 16 adjacent to the opening of the space to be enclosed.

[0033] The first guide track 14 and the second guide track 16 are mounted on top of the deck or surface 32 proximate the two side walls 26, 28. More particularly, the first guide track 14 and the second guide track 16 are positioned close to and in alignment with the first side wall 26 and the second side wall 28, respectively. Further, the first guide track 14 and the second guide track 16 are mounted, preferably, parallel to one another. The guide tracks 14, 16 are secured to the deck or surface 32 using any suitable means. A preferred means, however, is to secure the guide tracks 14, 16 to the deck or surface 32 using bolts spaced periodically along the length of the guide tracks 14, 16. The bolts are extended through holes that are bored through the guide tracks and are then fastened to the material that the deck or surface 32 is constructed of, which may be wood, plastic or concrete, for example. Further details regarding the positioning of the guide tracks with respect to the walls of the swimming pool and the mounting of the guide tracks to the deck or surface 32 is disclosed in the '613 patent and the '922 patent, the disclosures of which are incorporated herein by reference.

[0034] Still referring to FIG. 1, the cover 12 has a first side edge 34 and a second side edge 36. The second side edge 36 is spaced from and is, preferably, in parallel alignment with the first side edge 34. The cover 12 also has a front edge 37 and a rear edge 39 (see FIG. 2). The rear edge 39 is preferably fastened to a take-up drum 41, but may, alternatively, hang free so as to permit collection of the cover 12 in an open box 43 disposed below the deck or surface 32 when the cover 12 is in a fully or partially retracted position. The cover 12 is constructed using any suitable fabric. Preferably, however, the cover 12 is constructed from vinyl material reinforced with a polyester mesh to increase strength and wear resistance. The thickness 67 of the cover 12 in this embodiment is about four-tenths (4/10) of a millimeter (or about 0.015 inches). Materials of other thickness may be used being mindful that thicker material increases the weight and in turn may dictate a need for stronger components and a more powerful drive means 22.

[0035] Disposed along the first side edge 34 and the second side edge 36, respectively, are a first plurality of edge beads 38 and a second plurality of edge beads 40. Referring more specifically to FIGS. 3 A, 3B and 4, an individual edge bead 42 of one of the first and second pluralities of edge beads 38, 40 is illustrated as having a first section 44 and a second section 46 (the individual edge bead 42 is representative of each edge bead contained in the first and second pluralities of edge beads). The first and second sections 44, 46 are secured to the second side edge 36 using a pair of rivets 48 or some other suitable fastening device, such as spikes or prongs. Indeed, securing the beads 38 to the cover or fabric at the edges may be effected by any arrangement that precludes separation with substantial forces that may arise with water collecting on the cover or even people or animals on the cover. Each one of the edge beads of the first and second pluralities of edge beads 38, 40 are secured to their respective edges 34, 36 in a similar fashion.

[0036] The edge beads 38, 40, when assembled to the cover 12, have a diameter 68 that is from about 5.0 millimeters to about 15.0 millimeters, and that is, preferably, about 9.0 millimeters (or about 0.375 inches). The length of each edge bead 38, 40 is from about 15.0 millimeters to about 30.0 millimeters and is, preferably, about 25.0 mjn;™^™. (or about 1.0 inch). An aspect ratio of the edge beads, which is equal to the length divided by the diameter, is preferably about three (3), but may also be from about two (2) to about four (4), for the embodiment here described. Certainly beads of other shapes including cylindrical and even rectangular are within contemplation. Other aspect ratios and sizes are also contemplated.

[0037] When the edge beads 38, 40 are secured to their respective edges 34, 36, the front tip 50 of each edge bead will, preferably, abut the rear tip 52 of the adjacent edge bead. In practice, the distance 54 between the front tip 50 and the rear tip 52 is from zero (i.e., the tips abut one another) to less than about 1.0 millimeter. The beads 38, 40 are mounted to abut one another. A very small, almost non-existent, distance 54 may be found between some of the tips 50, 52 of adjacent edge beads. An abutting relationship is believed to facilitate the closing of the pool cover (as discussed below) by preventing binding of the edge beads 38 , 40 in their respective guide tracks 14, 16.

[0038] Referring to FIG. 3B, the edge beads 38, 40 can be seen to have rounded ends or tips 50A, 50B, 52 which are elliptical in cross section and can be approximately hemispherical with a blunt or transverse portion 50C and 50D along or on the axis 51 of the bead to facilitate force transmission when in alignment. The arcuate portions 50E and 5OF from the exterior wall 50G of the bead to the blunt or transverse portion 50C and 50D has a radius or shape selected so that if the bead is not in axial alignment in the track but, rather, is cocked or at some angle 50H relative to the axis 501 of the track (or more particularly the cut out portion or race 50J), then the bead will not jam. Rather, the friction is sufficiently small in magnitude such that the bead will slide or move within the cutout portion or race 50J of the track. The length 50K of the bead is also selected so that if or when a bead is cocked relative to the axis 501 of the cutout portion of the track, the bead cannot become wedged or jammed into the cutout portion of the track by application of a force F to one end 50A of the bead. In other words, the bead cannot rotate 50M about its center point 5OL and become wedged against the interior surface of the cutout portion 50J. [0039] The edge beads 38, 40 and the first guide track 14 and the second guide track 16 are, preferably, constructed from any suitable material that allows for the slideable relationship between the track and the beads while being less prone to corrosion. Acetal (which may be obtained from Dupont under the trade name DeMn) has been found to be suitable. Other suitable materials being contemplated include aluminum, stainless steel, nylon, teflon and alnico.

[0040] The first guide track 14 and the second guide track 16 function, in part, to guide the first side edge 34 and the second side edge 36, respectively, during operation of the enclosure system 10. The guide tracks 14, 16 also function to secure the cover 12 in place over the opening of the space to be enclosed when the cover 12 is substantially closed. Referring more specifically to FIGS. 5 A and 5B, the second guide track 16 has a cutout portion 60 that spans the length of the track (the first guide track 14 mirrors the second guide track 16 in construction, so only the shape and construction of the second guide track 16 is discussed). The cutout portion 60 has a wall 62 that is, preferably, circular in cross section. Notwithstanding the preference for a wall 62 that is circular in cross section, the wall 62 may exhibit other cross sectional geometries as well, depending on the cross sectional geometry of the assembled edge beads. As described and illustrated herein and above, however, it should be appreciated that circular or slightly elliptical cross sections for the wall 62 are preferred, as circular or slightly elliptical cross sectional shapes for the assembled edge beads are preferred.

[0041] The cutout portion 60 which can also be called a race also has a side opening 64 that is sized to accept the cover 12 but that is not so large that the edge beads can become dislodged from the track. In other words, the side opening 64 has a width 66 that is slightly larger than the thickness 67 of the cover 12 but that, at the same time, is smaller than the diameter 68 of the assembled edge bead. The tolerance 69 between the outer surface 70 of the edge bead and the inner surface 72 of the wall 62 is selected to allow for the edge bead to slide within the wall 62 while minimizing any binding of the beads in the cutout or race. Tolerances may vary based on the materials selected. For the illustrated embodiment, the tolerance 69 is, preferably, about 0.254 millimeters (or about 0.10 inches). Similarly, the width 66 of the side opening 64 may vary and for the present embodiment is about 3.0 millimeters (or about 0.125 inches). An alternative cross sectional geometry for the construction of the guide tracks 14, 16 is illustrated in FIG. 5 A. Here, guide track 73 is shown having a curved outer profile 74 and a flat section 75. The dimensions of the cutout portion 76 are essentially the same as those described above.

[0042] While the track 73 is here shown with a race or cutout portion sized to receive a bead, it should be understood that the track 73 may also be a simple rod supported by a plurality of pins attached to a support surface. The beads are C-shaped in cross section with an interior sized to snuggly and slideably fit over the rod so that they may slide there along.

[0043] Referring again to FIG. 1, the first positive drive 18 is secured adjacent to the first end 15 of the first guide track 14. Likewise, the second positive drive 20 is secured adjacent to the first end 17 of the second guide track 16. Referring now to FIG. 6, the first positive drive 18 includes a housing 80 and a bead sprocket 82 (the second positive drive 20 mirrors the first positive drive 18, so only the construction of the first positive drive 18 is discussed here). The housing 80 has a cutaway portion 84 that is sized and configured to accept the bead sprocket 82 therein. The cutaway portion 84 is semi-circular in shape and has a radius 85. The bead sprocket 82 is circular in shape and has a radius 87 that is slightly smaller than the radius 85 of the cutaway portion 84, thus allowing the bead sprocket 82 to rotate within the cutaway portion 84 of the housing 80.

[0044] The housing 80 is secured to a bracket means 88 by a pair of bolts 89 that extend through respective bolt holes 86 that are positioned on opposing sides of the cutaway portion 84. The bracket means 88 is itself secured to the back side of the rear wall 31 of the swimming pool 24, or to some other structure that is fixed with respect to the swimming pool, using any suitable means, such as, for example, bolts. The construction and mounting of bracket means suitable for the present invention is disclosed in the '613 patent and the '922 patent, previously referenced.

[0045] The drive means 22 functions to rotate the bead sprocket 82 inside the cutaway portion 84 of the housing 80. The drive means 22 is preferably an electric motor, but may, alternatively, consist of a variety of other means with which to rotate the bead sprocket 82. Contemplated alternatives to the drive means 22, for example, include an hydraulic system, a hand crank, an electric drill or other portable power tool, or similar known devices. The hydraulic system, for example, can include a power head that is used to rotate the bead sprockets and is connected to a hydraulic pump through hydraulic fluid pipes or hoses. The use of hydraulic drive means for similar purposes - i.e., for purposes related to driving a shaft that is part of an enclosure system - is disclosed in the '613 patent and the '922 patent, previously referenced. Referring to FIGS. 1 and 6, the drive means 22 is illustrated as being connected directly to the edge bead sprocket 82 by a drive shaft 115. Alternate drive means can include a gear assembly connected to the first positive drive with a drive head configured to be driven by a hand crank or with gearing so that an electric drill with a bit sized to engage the drive head can operate the cover system.

[0046] Still referring to FIG. 6, the housing 80 has a recess strip 90 that is formed on an inner wall or receiving surface 91 of the of the cutaway portion 84. The recess strip 90 is sized and configured to accept therein the upper portion 92 of the edge bead members as the edge bead members traverse the arc length 95 of the recess strip 90. The edge bead sprocket 82 has an outer or circumferential wall 81 with a plurality of inverse teeth 93 extending partially there through and sized and configured to accept therein the lower portion 94 of the edge bead members. With the inverse teeth 93 and the recess strip 90 so sized and configured, the edge beads become sandwiched between the housing 80 and the edge bead sprocket 82 as the edge bead sprocket 82 turns within the housing 80. It is noted here that the cutaway portion 84 is illustrated as being semi-circular in projection along the axis of the edge bead sprocket 82. Nonetheless, the cutaway portion 84 may be formed such that the inner wall or receiving surface 91 and the recess strip 90 extend a further distance about the circumference of the edge bead sprocket 82.

[0047] The recess strip 90 terminates at the leading or front-most edge 104 of the arc length 95. At this location, the recess strip 90 merges into a second cutout portion 103 which has the same cross sectional dimensions and shape as the cutout portion 60 belonging to the corresponding guide track. In other words, the second cutout portion 103 has a wall 105 and a side opening 106 that are sized and configured to be compatible with the wall 62 and side opening 64 of the guide track above described.

[0048] A first connector track 19 is, if desired, positioned between the first end 15 of the first guide track 14 and the housing 80 of the first positive drive 18. Likewise, a second connector track 21 is positioned between the first end 17 of the second guide track 16 and the housing 80 of the second positive drive 20. The connector tracks 19, 21 have a cutout portion 110 and corresponding walls and side openings that form a smooth-walled and continuous link between the edge bead exit and entry port 102 and the cutout portion 60 located at the first end 15, 17 of the corresponding guide track 14, 16. In other words, the cutout portion 110 has a wall 111 and a side opening 112 that are sized and configured to be compatible with the wall 62 and side opening 64 of the guide track above described and with the wall 105 and side opening 106 of the second cutout portion 103 above described. The connector tracks 19, 21 are positioned at points expected to be most prone to wear from the forced entry of the edge beads into the guide tracks and facilitate maintenance, replacement and repair of the enclosure system 10 without having to replace the guide tracks 14, 16.

[0049] As the edge bead sprocket 82 rotates within the cutaway portion 84 of the housing 80, the edge beads are gripped by the inverse teeth 93 and thereby forced to move in the direction of rotation of the edge bead sprocket 82. More specifically, when the edge bead sprocket 82 rotates in the closing direction 97 - i.e., the direction whereby the cover 12 is pushed out and over the top of the swimming pool 24 - the trailing edge 96 of each inverse tooth 93 will abut the trailing edge 98 of the lower portion 94 of a corresponding edge bead and force the edge bead to move in the direction of rotation 97 along the arc length 95 of the recess strip 90. As each edge bead passes by the leading or front-most edge 104 of the arc length 105 (or the recess strip 90) each edge bead is forced into the second cutout portion 103 of the housing 80. Each edge bead is then forced along the length of the second cutout portion 103 and then into and along the cutout portion 110 of the respective connector track 19, 21. Finally, each edge bead emerges from the cutout portion 110 of the connector track 19, 21 and enters the cutout portion 60 of the guide track 14, 16 where each edge bead is then forced along the length of the guide track 14, 16 in the cutout portion 60 thereof.

[0050] It should be appreciated from the discussion above that the edge beads, when connected to the cover 12 such that the rear tip 52 of each bead abuts the front tip 50 of an adjacent bead, are forced along their respective guide track 14, 16 by the force applied through the adjacent bead, hi other words, when the edge beads are lined up in their respective guide track, a "segmented rod" is simulated whereby the force applied to the bead just exiting the recess strip 90 is transmitted to and through each of the edge beads that are then lined up in a respective guide track 14, 16. As mentioned above, the close tolerance between the outer surface 70 of the edge bead and the inner surface 72 of the wall 62 (as is the case with the second cutout portion 103 and the cutout portion 110 that is formed in the connector track 19, 21) prevents the edge beads from overlapping or becoming kinked in the guide track 14, 16. Hence, the action of the positive drive 18, 20 forces the edge beads, together with the cover to which they are attached, along the guide track 14, 16 as the cover 12 is being closed over the swimming pool 24.

[0051] In a similar fashion, when the edge bead sprocket 82 rotates in the opening direction 99, such that the cover 12 is retracted from over the top of the swimming pool 24, the leading edge 100 of each inverse tooth 93 will abut the leading edge 101 of the lower portion 94 of a corresponding edge bead and force the edge bead to move in the opening direction of rotation 99 along the arc length 95 of the recess strip 90. When the bead sprocket 82 rotates in the opening direction 99, however, the edge beads are no longer "pushed" down the guide track 14, 16 but, rather, are "pulled" together with the cover 12 to which they are attached.

[0052] Generally, the opening of the space to be enclosed is made with concrete walls and flooring. Since the concrete surfaces are typically not square, the lengths of the opening of the space to be enclosed may not be equal or even parallel. Thus, one side of the cover 12 may arrive at the end of the length before the other side arrives, leaving a gap not enclosed by the cover 12. To accommodate for this discrepancy, the clutch means 140 can be strategically placed on the shaft 120. For example, if one clutch means 140 is placed between the first and second positive drives 18, 20 as shown in FIG. 1, the drive means 22 should be placed on the side having the shorter length. In this aspect, the drive means 22 is positioned opposite to the side having the longer length so that when the cover 12 at the side of the longer length arrives at the end first, the clutch means 140 is disengaged allowing that side to crease from advancing forward and the other side can progress until it also reaches the end. The drive means 22 can be arranged as shown in FIG. 1 or switched to the other end depending on which side of the opening is shorter.

[0053] Referring to FIGS. 7A and 7B, two alternative arrangements for rotating the bead sprockets are illustrated. In these embodiments, the clutch means 140 is integrated into the first and second positive drives 18, 20. In FIG. 7 A, for example, a single drive means 22 is used to rotate the bead sprockets 82 in both the first positive drive 18 and the second positive drive 20. This arrangement employs a shaft 120 that extends from the edge bead sprocket 82 of the first positive drive 18 to the edge bead sprocket 82 of the second positive drive 20. The first and second ends 128, 129 of the shaft 120 are connected to the edge bead sprockets 82 of the first and second positive drives 18, 20 using any suitable means, such as, for example, flanges 130 that are threaded onto the ends of the shaft and then bolted to the respective edge bead sprockets 82. [0054] The first and second positive drives 18, 20 can advance or retract the opposite edges of the cover 12 at different speeds when the shaft 120 is used. For example, one edge of the cover 12 may move faster or slower due to discrepancies in the manufacturing tolerances of the components, alignment of the first and second drive tracks 14, 16 and the trueness of the first and second side walls 26, 28. The shaft 120 drives two bead sprockets 82 to advance or retract the first and second plurality of edge beads 38, 40. When the first or second plurality of edge beads 38, 40 advances or retracts along the respective first and second drive tracks 14, 16 faster than the other side, the cover 12 can become skewed or angled relative to the wall of the pool. Eventually, the cover 12 can become skewed enough to cause the enclosure system 10 to bind or the cover 12 to rip.

[0055] Excess torque drastically increases in one of the first and second ends 128, 129 of the shaft 120 when the cover 12 becomes skewed. The problem of one side of the cover 12 advancing faster than the other is overcome by placing at least one clutch means 140, shown generally, at either the first or second positive drives 18, 20 or both as illustrated in FIG. 7 A. If one clutch means 140 is used, the system would have a similar protection system as discussed with respect to FIG. 1, where the clutch means 140 is placed between the first and second ends 128, 129 of the shaft 120. Clutch means 140 in the embodiments illustrated in FIGS. 1, 7 A and 7B may include, for example, a slip clutch, a pneumatic slip clutch, a torque limiting coupling, a ball- detent torque limiter, a friction torque limiter or other devices known by one skilled in the art to transfer rotational torque during operation and to permit relative movement (i.e., slip) between portions of a shaft to prevent torque overloading and in turn damage to the mechanism and/or overrunning. The clutch means 140 can be made of a steel, plastic or alloy material, preferably a material having corrosion resistant properties, such as 304 and 316 stainless steel. More than one clutch means 140 may be used depending on the design requirements and the length of the shaft 120. For example, clutch means 140 may be incorporated into each of the bead sprockets 82. Examples of clutch means 140 are illustrated in FIGS. 8-15 further discussed below. [0056] Optional Bearings 121 stabilize and support the shaft 120 as needed. That is, the bearings 121, if needed, are spaced along the length of the shaft 121 in a number and spacing there between that depends on the width of the pool 24 and the length of the shaft 120. The bearings 121 are secured to the back side of the rear wall 31 of the swimming pool 24, or to some other structure that is fixed with respect to the swimming pool, using any suitable means, such as by bearing housings that are themselves fastened to a bracket means in a manner similar to that discussed above with respect to the housing 80. The bearings will, for example, stabilize the shaft 120 and in turn restrict shaft flexion when it is heavily loaded.

[0057] In FIG. 7B, an alternative arrangement is illustrated whereby a second drive means 122 is connected directly to the edge bead sprocket 82 of the second positive drive 20 in a manner similar to that used to connect the drive means 22 to the edge bead sprocket 82 of the first positive drive. That is, and by way of analogy with the first positive drive, a key comparable to key 125 is set in a groove in a drive shaft comparable to drive shaft 115 and mates with a corresponding groove comparable to the groove 126 and aperture arrangement seen in FIG. 6 that is cut into shaft aperture 127 that extends through the central axis of the edge bead sprocket. A nut (not illustrated) then secures the edge bead sprocket onto the drive shaft. In the alternative arrangement that employs two drive means 22, 122, care must be taken to ensure that the drive means 22, 122 are timed to rotate the edge bead sprockets like sprocket 82 of the positive drives 18, 20 such that the edge bead sprockets rotate at the same rate or speed of rotation. This concern is, however, substantially alleviated when a shaft 120 is disposed between the edge sprockets 82 as illustrated in FIG. 7 A.

[0058] As discussed above with respect to FIG. 7A, a clutch means 140A and 140B can be integrated into either the first or second positive drives 18, 20, or both, as illustrated in FIG. 7B. The cover system could have a similar protection system as discussed with respect to FIG. 1 if one clutch means 140 is used. In addition, a limit switch may be used at each side of the cover 12 to stop advancement of each side of the cover independently. The clutch means 140A and 140B are similar to the clutch means 140 discussed above with respect to the embodiments illustrated in FIGS. 1 and 7A, which include, for example, a slip clutch, a pneumatic slip clutch, a torque limiting coupling, a ball-detent torque limiter, a friction torque limiter or other devices known to one skilled in the art to transfer rotational torque during operation and to permit relative movement (i.e., slip) between portions of a shaft to prevent torque overloading and in turn damage to the mechanism and/or overrunning. As discussed above, the clutch means 140A and 140B can be made of a steel, plastic or alloy material, preferably a material having corrosion resistant properties, such as 304 and 316 stainless steel.

[0059] A take-up drum 41 is positioned below the positive drives 18, 20 and serves to store the cover 12 when the cover 12 is partially or completely retracted from the swimming pool 24. The take-up drum 41 can have a cylindrical shape. The surface of the take-up drum 41 can also be curved or arcuate so that the diameter in the middle of the drum is larger than the diameter on the ends. The smaller outside diameter allows the beads 38, 40 to wind-up evenly with the cover 12 on the take-up drum 41. For example, when the beads 38, 40 are gathered on the ends, the wound-up cover 12 is prevented from gathering in the middle. The take-up drum 41 is mounted in the box and optimally to the back side of the rear wall 31 of the swimming pool 24. A bracket means 135 is mounted at both ends of the take-up drum 41 and secured to the wall using bolts or the like. Reference is again made to the '613 patent and the '922 patent for details regarding the construction and mounting of suitable brackets. Bearings or bushings (not illustrated) are positioned between the brackets 135 and the ends of the take-up drum 41 to hold the take-up drum 41 and to allow for rotation of the drum 41 relative to the bracket means 135.

[0060] The take-up drum 41 is rotated or driven using a pulley and belt arrangement. Specifically, a first pulley 136 is secured to the bead sprocket 82 of the second positive drive 20 while a second pulley 137 is secured to the take-up drum 41. A belt 138 connects the first and second pulleys 136, 137 together. The belt is allowed to slip on the pulleys 136, 137 to account for the change in diameter of the take-up drum 41 as the cover 12 is collected thereon or removed therefrom. A slip clutch or friction plate can also be used to allow for the slippage and account for the change in diameter. Alternatively, the cover 12 may be allowed to simply collect in the box 43 that would otherwise house the take-up drum 41.

[0061] As shown in FIGS. 8-11, one embodiment of a clutch means 140C suitable for use as clutch 140, 140A or 140B is provided to allow the shaft 120 to slip thereby alleviating excess torque build-up. The clutch means 140C includes a first portion 142 and a second portion 150, which are held together by frictional force, thereby allowing the first and second ends 128, 129 of the shaft 120 to rotate. When a torsional force becomes greater than a preselected magnitude determined by the frictional coefficients of the surfaces of the first and second portions 142, 150, the frictional force is overcome thereby allowing first and second portions 142, 150 to rotate with respect to each other. The shaft 120 is cut at a point between the first and second ends 128, 129, or provided in separate parts, then spliced back together using the clutch means 140.

[0062] The first portion 142 is circular shaped having an outer surface 143 extending around the circumference of the first portion 142. Grooves 144 are formed into the outer surface 143 by cutting, milling, molding, drilling or the like. The grooves 144 are formed in the shape of a notch, channel or indent sufficient to provide a recess for a spring plunger 160, such as a round-nose spring plunger as provided in 2004 Catalog of McMaster Carr Supply Co., pg. 2416. The spring plunger 160 can be made of a corrosion resistant material, such as 304 or 316 stainless steel. A coupling assembly 145 may be any device known by one skilled in the art to attach the shaft 120 to the clutch means 140C, such as a clamp, flange, keyway or the like. For example, the coupling assembly 145 includes a fixed piece 146 and a removable piece 148 is attached to the first portion 142. The fixed piece 146 is attached to one side of the first portion 142 and arranged to extend out substantially perpendicular from the surface of the first portion 142. The fixed piece 146 is positioned substantially in the center of the first portion 142 and adapted to receive an end of the shaft 120. The removable piece 148 is also adapted to receive an end of the shaft 120 and fitted against the fixed piece 146. An aperture 147 is formed through the coupling assembly 145 and a bolt 149 is inserted into the aperture 147.

[0063] The second portion 150 is also circular shaped and has a bore 152 formed into one side thereof. The bore 152 provides an inner surface 154 that is planar and is sized to accommodate the first portion 142. A coupling assembly 155 may be any device known by one skilled in the art to attach the shaft 120 to the clutch means 140C, such as a clamp, flange, keyway or the like. For example, the coupling assembly 145 includes a fixed piece 156 and a removable piece 158 is attached to the second portion 150. The fixed piece 156 is attached to a side of the second portion 150 opposing the bore 152 and arranged to extend out substantially perpendicular from the surface of the second portion 150. The fixed piece 156 is positioned substantially in the center of the second portion 150 and adapted to receive an end of the shaft 120. The removable piece 158 is also adapted to receive the end of the shaft 120 and fitted against the fixed piece 156. An aperture 157 is formed through the coupling assembly 155 and a bolt 159 is inserted into the aperture 157.

[0064] The first and second portions 142, 150 are assembled to the shaft 120 in the following manner. The shaft 120 is cut into or provided as two parts. An aperture is drilled or bored into one end of each part of the shaft 120. The first portion 142 is attached to an end of one part of the shaft 120 by placing the shaft 120 onto the fixed piece 146 of the coupling assembly 145, fitting the removable piece 148 on the opposite side of the fixed piece 146 and placing the bolt 149 through the coupling assembly 145 and shaft 120. The second portion 150 is attached to one end of the other part of the shaft 120 by placing the shaft 120 onto the fixed piece 156 of the coupling assembly 155, fitting the removable piece 158 on the opposite side of the fixed piece 156 and placing the bolt 159 through the coupling assembly 155 and shaft 120. The first portion 142 is then inserted into the bore 152 of the second portion 150. A first thrust washer 170 is sandwiched between the first and second portions 142, 150. The surfaces of the first thrust washer 170 abut against the surface opposing the coupling assembly 145 of the first portion 142 and inner surface 154 of the second portion 150.

[0065] Apertures 151 are provided in the second portion 150 in the same radial line as the grooves 144 of the first portion 142. Spring plungers 160 are then inserted through apertures 151 until a portion of the set screw enters the groove 144. The set screws include, for example, a slotted head 162, a round tip 164 and threads 166. The round tip 164 provides an adjustable surface for further setting torque limits. When the torque exceeds the adjusted limit, the first portion 142 slips within the second portion 150 and the spring plunger 160 slips from one groove 144 to another until the excess torque has been eliminated.

[0066] A second thrust washer 172 is slid over the shaft 120 and against the first portion 142 to abut against the surface where the coupling assembly 145 extends out from the first portion 142. A locking ring 174 locks the second thrust washer 172 against the first portion 142. The locking ring 174 locks against the second portion 150 thereby holding the first and second portions 142, 150 together. The first and second portions 142, 150 provide a driving relationship between the positive drives 18,20 while allowing relative movement between the positive drives 18, 20 upon development of torsional forces of preselected magnitude.

[0067] Referring now to FIGS. 12-15, a second embodiment of a clutch means 140D suitable for use as clutch 140, 140A or 140B is provided having a similar function as described above with respect to FIGS. 8-11. The clutch means 140D includes a first portion 180, a second portion 190 and a third portion 200, which couple the parts of the shaft 120 together to allow the first and second ends 128, 129 of the shaft 120 to rotate under normal operating conditions. The second and third portions 190, 200 are fixed to prevent rotation with respect to each other. When a torsional force becomes greater than a preselected magnitude determined by the frictional coefficients of the surfaces preventing the first portion 180 from rotating within the second portion 190, the frictional force is overcome thereby allowing the first portion 180 to rotate with respect to the second and third portions 190, 200.

[0068] The first portion 180 has a circular shape with an outer surface 182 extending around the circumference of the first portion 180. A coupling assembly 184 may be any device known by one skilled in the art to attach the shaft 120 to the clutch means 140D, such as a clamp, flange, keyway or the like. For example, the coupling assembly 184 includes a fixed piece 186 and a removable piece 188 is attached to the first portion 180. The fixed piece 186 is attached to one side of the first portion 180 and arranged to extend out substantially perpendicular from the surface of the first portion 180. The fixed piece 186 is positioned substantially in the center of the first portion 180 and adapted to receive an end of the shaft 120. The removable piece 188 is also adapted to receive an end of the shaft 120 and fitted against the fixed piece 186. An aperture 187 is formed through the coupling assembly 184 and a bolt 189 is inserted into the aperture 187.

[0069] The second portion 190 has a split flange configuration including a first half 192 and a second half 194. The first and second halves 192, 194 are held together using fasteners, for example, bolts 196 and nuts 198. The second portion 190 includes a bore 191 that extends into the first and second halves 192, 194 and is sized to accommodate the first portion 180. The bore 191 provides an inner surface 193, which is lined with a material having a high coefficient of friction. The material of the inner surface 193 is affixed to the bore 191 by an adhesive.

[0070] The third portion 200 includes a plate 202 having a circular configuration that substantially matches the third portion 190. A coupling assembly 204 may be any device known by one skilled in the art to attach the shaft 120 to the clutch means 140, such as a clamp, flange, keyway or the like. For example, the coupling assembly 204 includes a fixed piece 206 and a removable piece 208 is attached to the third portion 200. The fixed piece 206 is attached to a side of the third portion 200 opposing the third portion 190 and arranged to extend out substantially perpendicular from the surface of the third portion 200. The fixed piece 206 is positioned substantially in the center of the third portion 200 and adapted to receive an end of the shaft 120. The removable piece 208 is also adapted to receive the end of the shaft 120 and fitted against the fixed piece 206. An aperture 207 is formed through the coupling assembly 204 and a bolt 209 is inserted into the aperture 207.

[0071] The first, second and third portions 180, 190, 200 are assembled together to form the clutch means 140D and attached to the shaft 120. The shaft 120 is cut into or provided as two parts and an aperture is drilled or bored into one end of each part of the shaft 120. The first portion 180 is attached to an end of one part of the shaft 120 by placing the shaft 120 onto the fixed piece 186 of the coupling assembly 184, fitting the removable piece 188 on the opposite side of the fixed piece 186 and placing the bolt 189 through the coupling assembly 184 and shaft 120.

[0072] The third portion 200 is attached to one end of the other part of the shaft 120 by placing the shaft 120 onto the fixed piece 206 of the coupling assembly 204, fitting the removable piece 208 on the opposite side of the fixed piece 206 and placing the bolt 209 through the coupling assembly 204 and shaft 120. The second portion 190 is attached to the third portion 200 sandwiching a thrust washer 210 in between. Fasteners such as bolts 212 and nuts 214 attach the second and third portions 190, 200 together and prevent the second and third portions 190, 200 from rotating with respect to each other.

[0073] The first portion 180 is then inserted into the bore 191 of the second portion 190 and positioned to abut against the thrust washer 210. Thrust bearings 216 are placed on the outside of the first portion 180 and attached to the second portion 190 using machine fasteners 218. The thrust bearings 216 apply a small force against the surface of the first portion 180 towards the third portion 200. The inner surface 193 creates a mechanical relationship therebetween to transfer rotational torque in the clutch means 140. When the torque exceeds the limit of the frictional force, the first portion 180 slips within the second portion 190 until the rotational torque is reduced below the predetermined magnitude.

[0074] Generally, the clutch means corrects the cover 12 when it becomes skewed. The clutch means 140 allows the side of the cover 12 that is not advancing as fast as the other to catch up with the other side. The clutch means 140 can also be incorporated into each of the bead sprockets 82 to provide torque release at each individual bead sprocket 82.

[0075] While the enclosure system 10 has been described with reference to the specific embodiment described, the descriptions are only illustrative and are not to be construed as limiting the invention. As such, the optimal dimensional relationships for the parts of the preferred embodiment of the invention can be varied in size, materials, shape, configurations, form, function and manner of operation. The optimal dimensional relationships, use and assembly that are readily apparent to those skilled in the art and all equivalent relationships to the embodiments illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

[0076] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.