Cable operated automatic pool cover system using buoyant slat pool covers

Abstract: A control system for controlling the movement of a pool cover comprised of interconnected rigid buoyant slats and which uses a driven cable through a remotely powered source as a primary drive mechanism. The swimming pool cover is typically mounted on a drum and often in a submerged condition. In order to overcome the buoyant forces, the drive and control means must provide a braking action to the pool cover which would tend to unwind from a drum as a result of buoyant forces. The drive mechanism employs a cable drive which will wind a cable upon a cable reel or drum mounted in a remote location with respect to the cover drum. Cable could be trained from the cover drum to this cable drum in order to power same for rotation in at least a wind-up direction and could be used for controlling a braking action in the unwinding direction.

Description: 1. Field of the Invention This invention relates in general to certain new and useful improvements in an automatic pool cover system utilizing cable drives for controlling wind-up and payout of a buoyant preferably slatted swimming pool cover from a cover drum. 2. Brief Description of Related Art The vast majority of automatic swimming pool cover systems use electrically operated using electric motor drives. However, electric motor drive systems present numerous safety hazards and, moreover, the electric motors must be completely insulated from a water environment. Even when the pool cover drive systems are located in a separate subterranean environment in proximity to the swimming pool, rain water and other water from the swimming pool itself tends to collect in the subterranean compartment which is used for housing the electric motors and associated electrical components. Moreover, it has been recognized that at least fifty percent of failures in most automatic pool cover systems is the result of the inherent problem of water damage. In order to overcome this problem, the present applicant designed and developed a pool cover system which totally relies upon a hydraulic drive located at or near the swimming pool. An electric power pack is provided at a remote location for pumping the hydraulic fluid. One such system is described in U.S. Patent No. 5,184,357, dated February 9, 1993, in which the applicant describes an automatic swimming pool cover using a hydraulic drive for providing cover drum rotation during extension and rotating the cover drum for cover retraction. The present applicant has proposed and has designed a pool cover system for preferably relatively rigid buoyant slatted pool covers which relies upon a cable drive system. The cable drive is powered by a power pack in a remote location. The present invention therefore relies totally upon a cable system which is powered from a remote location and, therefore, the drive can be either an electric drive, a hydraulic drive or the like. Automatic pool cover systems utilizing interconnected rigid buoyant slats which roll up on a submerged or elevated drum are described in U.S. Patent No. 3,613,126 to R. Granderath, which discloses a swimming pool in combination with an automatic pool covering apparatus, and a method of controlling movement of a buoyant pool cover which respectively comprise all of the features of the preambles of claims 1 and 8 and are quite popular in the United States and also in Europe. These pool cover systems utilize passive forces arising from buoyancy or gravity to propel the cover and extend the cover across the swimming pool. However, there must be some mechanism to prevent the retracted cover from unwinding responsive to these passive forces. Granderath provides a worm gear drive mechanism for winding the cover and preventing cover drum rotation when not powered. However, worm gear drive mechanisms are not effective and insufficient for the intended purposes. There has been a need for a pool cover system in which a swimming pool cover can be driven across a swimming pool to a closed position and wound back onto a cover drum in order to an opened position in order to provide access to the swimming pool and which could be powered completely from a remote location. The present invention finds its employment in a cable drive in which the power source is remotely located. BRIEF SUMMARY OF THE INVENTION In accordance with the present invention, which is embodied in a swimming pool in combination with an automatic pool cover apparatus according to claim 1 and a method of controlling movement of a buoyant pool cover according to claim 8, a cable drum is located at a remote location and is powered from a separate power source at that remote location. The power source could be either an electric motor or a pneumatic drive motor or any other type of motive means. The cable drum is also trained about a separate cable drum mounted on the cable drum shaft which carries the cover. Thus, cable can be pulled from the cable drum on the cover drum shaft and also wound onto the powered cable drum. In like manner, speed of movement of payout of the cable from the powered cable drum can be controlled by a brake means at a remote location to thereby control any unwinding of the cover from the cover drum. The drive system of the invention utilizes the extensive upward buoyant force of the cover and its ability to cover the swimming pool and converts this force into a usable controllable drive means. In the present invention, the system employs a stainless steel cable or other non-corrosive cable or force transmitting means and winds this cable onto the cover drum or, otherwise, to a separate reel attached to the cover drum while the cover is being propelled across the swimming pool by its own inherent buoyant force. In this case, the drum pays out the cable at a controlled and essentially constant rotational speed by a winch-like means operated either by a hydraulic or electric motor at a location remote from the swimming pool. BRIEF DESCRIPTION OF THE DRAWINGS Having thus described the invention in general terms, reference will now be made to the accompanying drawings in which: Figure 1 is a fragmentary schematic perspective view, partially broken away, showing one form of automatic pool cover system in accordance with the present invention; and Figure 2 is a fragmentary schematic perspective view, partially broken away, and showing a modified form of automatic pool cover system in accordance with the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now in more detail and by reference characters to the drawings, there is illustrated in Figure 1 an overall automatic pool cover system in combination with a swimming pool. This pool cover system specifically shows the drive mechanism in a subaqueous condition and with a special subterranean compartment as hereinafter described. More specifically, there is illustrated a pool deck 70 surrounding a swimming pool wall 72 and which provides an interior swimming pool cavity 74 containing water therein. The automatic pool cover mechanism is located in a separate subterranean compartment 76 formed by a subterranean wall 78, as shown. A pool cover lid 80 is disposed over the compartment 76 and provides access thereto. A cover dispensing and winding mechanism 82 is provided and includes a subaqueously located cover drum 84. Generally, the cover dispensing and winding mechanism 82 is located in its own separate compartment for easy access and for purposes of cleaning and repair. By further reference to Figures 1 and 2, it can be seen that the cover drum 84 is mounted on a drum shaft 90 which projects through a sealed aperture 91 in the wall 78, and which is also hereinafter described in more detail. The drum shaft may also be contained in an interior compartment and mounted to the inside of the pool wall. A buoyant slat type cover 92 is wound upon the cover drum and may be unrolled therefrom to extend over the upper surface 94 of a swimming pool body of water. Also mounted on the drum shaft 90 and being co-axial with the drum 84 is a cable reel 96 and which receives a cable 98. The cable 98 is trained about a cable spool 100 which is, in turn, coupled to and driven by a motor 102. It can be observed that the motor has an output shaft 104 which is connected to a worm gear reducer 116, the latter of which serves to provide a braking action to the cover drum. The reducer 106 is mounted to the cable spool 100 for rotating same. Since the steel cable may be as thin as two or three millimeters, the reel could be mounted on the inside of the pool wall. At approximately twenty revolutions of the drum to close the pool, a three to four layer cable buildup would amount to a cable reel width of only eight to 10 millimeters. It should also be observed that the cable spool 100 and the drive motor 102 is remotely located with respect to the pool cover mechanism 82. In this way, the cable can be trained through a wall or other structure and connected to the spool 100 when the latter is in a remote location. The cover which is used in the system of the present invention is preferably a buoyant type cover comprised of a plurality of interconnected buoyant slats. When this cover is wound onto a drum, particularly when the latter is in a submerged condition, as shown in Figure 1, the diameter of the drum will increase. The torque on the drum shaft 90 increases and is the product of the upward buoyant force of the slat area unwound from the cover drum and still submerged beneath the surface of the water multiplied by the instant radius of the cover drum. One means to brake the cover drum in the unwinding direction, when the cover is moving to the closed position, is a worm gear reducer, as shown. Another means, such as a ratchet and pawl mechanism, can also be used. In place of a worm gear reducer or a ratchet and pawl, it is possible to use a conventional braking mechanism, such as a disc (not shown), engaged on the shaft and engaged by brake shoes, similar to that shown in Figure 2. For this purpose, any type of braking mechanism may be employed in accordance with the present invention. It can be observed that when the cover is unwinding from the drum, it will cause an unwinding of the cable 98 from the spool 100 and which will thereupon wind onto the reel 96. In addition, when it is desired to wind the pool cover onto the drum, the motor 102 is energized causing rotation of the spool 100 and the causing the cable 98 to rotate the drum shaft 90 as well as the reel 96 and the cover drum 84. In accordance with the present invention, it is possible to run the cable through any subterranean structure or other structure so that it does not encumber access to the swimming pool itself. In this case, the cable 98 is shown as being trained around the reel 96 and over an idler roller 112 through a retaining tube 114 to the spool 100. Figure 2 illustrates an alternate embodiment of the present invention. In this case, reference numerals used to identify those components in Figure 1 will be used to identify like components in Figure 2. In the embodiment of the invention as shown in Figure 2, there is a conventional brake mechanism 120 which is used in place of the worm gear reducer 106. In this case, there is provided a brake disc 122 acted upon by brake shoes 124. A suitable control mechanism would be provided for operation of the brake mechanism. In this way, a braking force can be provided, if desired. Also in the embodiment of the invention as illustrated in Figure 2, a second reel 126 is also mounted on the drum shaft 90 adjacent to the spool 100. The spool 100 continues to pay out and receive the cable 98. However, a second cable 128 is trained about the second reel 126, also in the manner as shown in Figure 2. The second cable 128 similarly winds up onto the reel 100. Moreover, it can actually be continuous with the cable 98, if desired. In accordance with the above-identified construction, it can be observed that a controlled drive is provided in both directions, that is, the first cable 98 would provide a positive drive to roll cable onto the drum. The second cable 128 provides a controlled rotation of the drum shaft 90 and, hence, the drum 84, and thereby provides a controlled payout of the cover 92. This mechanism is highly effective, particularly when used with a brake mechanism, such as the mechanism 120. It should be understood that the aforementioned system may also be applied to systems where drums are placed above the water surface and subject to gravitational as opposed to buoyant forces. This arrangement would be equally effective.

Claims: A swimming pool in combination with an automatic pool cover apparatus incorporating a buoyant pool cover, preferably a buoyant type cover (92) comprised of a plurality of interconnected buoyant slats, wherein movement of same is controlled to a closed position over the swimming pool (74) and to an opened position where the cover is wound upon a cover drum, and which cover apparatus comprises the cover drum (84) rotatably mounted in a subaqueous position or in a position above the water surface and a power source (102) for driving said cover drum, characterized by the apparatus further comprising: a) a cable reel (96) operatively mounted with respect to said cover drum and being rotatable in relationship to said cover drum; b) said power source (102) for controlling movement of a cable (98) and being at a remote location from said swimming pool; and c) a cable (128) trained about said cable reel (96) and extending from said cable reel (96) in proximity to said swimming pool to said power source (102) and being operable by said power source (102) to cause rotation of said cable reel (96) and thereby causing rotation of said cover drum (84) to wind the pool cover onto the drum. The swimming pool in combination with the automatic pool cover apparatus of Claim 1 further characterized in that said cover drum (84) and said cable reel (96) are co-axially mounted on a common shaft means (90). The swimming pool in combination with the automatic pool cover apparatus of Claim 2 further characterized in that said cable reel (126) rotates at the same rate of speed as said cover drum (84). The swimming pool in combination with the automatic pool cover apparatus of Claim 1 further characterized in that said power source (102) comprises a cable spool (100) and motive means (102) for operating said cable spool to cause a simultaneous unwinding of cable from the cable reel and onto the cable spool in response to operation of said motive means. The swimming pool in combination with the automatic pool cover apparatus of Claim 1 further characterized in that a brake means (120) is operatively connected to a motive means (102) to control speed of movement of said cable (98) and said cover drum when said cover unwinds from the cover drum to the closed position. The swimming pool in combination with the automatic pool cover apparatus of Claim 1 further characterized in that a pair of cable reels (96, 126) is mounted co-axially with respect to said cover drum and one cable pays out from one of said cable reels to said cable drum and the other receives cable wound thereon simultaneously with the payout of the cable from the first cable reel therefrom. The swimming pool in combination with the automatic pool cover apparatus of Claim 1 further characterized that roller means (112) is located above the water surface of the swimming pool and that the cable extends from the reel over said roller means to said cable drum. A method of controlling movement of a buoyant pool cover, preferably a slatted type buoyant pool cover (92), to a closed position over a swimming pool (74) and to an opened position where the pool cover is wound upon a cover drum (84), said method is characterized by comprising the steps: a) providing during controlling movement of the cover to the opened position a pulling force on a cable (128) operatively trained with respect to the cover drum (84) and providing that pulling force at a remote location; and b) providing during controlling movement of the cover to the closed position a braking force to said cable (128) and, hence, to said cover drum (84) to control the rate of movement of the cover from the cover drum. The method of Claim 8 further characterized in that said method comprises training said cable about a cable reel (96) mounted co-axially with respect to said cover drum (84) and about a cable spool (100) located at a remote source and which is powered at said remote source by motive means (102). The method of Claim 8 further characterized in that said method comprises simultaneously winding one cable about a cable reel (96) and withdrawing cable from another cable reel (126) also mounted co-axially with respect to said drum.

Inventors: LAST HARRY J, LAST, HARRY J.
Applicants: LAST HARRY J, LAST, HARRY J.
Application year: 2001
Main classification: E04H4
IPC codes: E04H4