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[0001]    This application is based on the foreign priority of Canadian Application No. 2,923,280, filed Mar. 10, 2016. 
       BACKGROUND OF THE INVENTION 
       [0002]    Safety pool ladders for above-ground swimming pools are known in the prior art. One well known type of safety pool ladder for above-ground swimming pools is described in patent documents U.S. Pat. No. 3,908,795, to Gannon (Sep. 30, 1975) and US20130025042A1, to Lin et Al. (Jan. 31, 2013). This type of safety pool ladder is generally represented by a substantially A-shaped ladder disposed in a saddle-like manner over the pool wall of a conventional above-ground swimming pool. The safety pool ladder typically has a relatively small horizontal platform at the top, and a set of ladder steps or rungs on each side of its A-shaped configuration, for climbing over the pool wall from either side thereof. 
         [0003]    Furthermore, the set of ladder steps or rungs on the outside of the pool are mounted to a pair of parallel ladder side members having their upper ends pivotably attached to an upper portion of the A-shaped ladder. Thus, a user may selectively pivot this assembly upwardly when the pool must not be accessed unattended by an adult. 
         [0004]    This type of safety pool ladder of the prior art, with its ladder steps and side members assembly thus pivoted upwardly, has the disadvantage of being relatively unstable during strong wind conditions, to a point of sometimes rolling over and tumbling out of the pool if not well anchored. This type of safety ladder further requires sufficient space near the pivotable assembly outside the pool, for allowing the relatively long pair of ladder side members to freely pivot upwardly. Finally, this type of safety ladder, with its ladder steps and side members assembly pivoted upwardly does not always particularly blend well aesthetically with pool side design furniture. 
         [0005]    Another known type of safety pool ladder for above-ground swimming pools is described in patent documents U.S. Pat. No. 8,191,682B2, to Lipniarski (Jun. 5, 2012), U.S. Pat. No. 8,430,205B2, to Leung (Apr. 30, 2013), and FR2986032, to Bouillet (Jan. 23, 2012). This type of safety ladder also has a substantially A-shaped configuration, with a relatively small horizontal platform at the top and sets of ladder steps or rungs on each side thereof. This type of safety ladder further has a deployable or otherwise removably attachable cover that a user may selectively use to hide or at least block access to the set of ladder steps on the outer side of the pool wall, in order to prevent access to the pool. 
         [0006]    This type of safety pool ladder solve some of the disadvantages of the previously described type of safety pool ladder by being more stable during strong wind conditions, requiring only limited space to be functional, and being more aesthetically appealing. On the other hand, this type of safety pool ladder may be less secure since it may allow some determined 7-8 year old kids to have unattended access to the pool by slightly jumping up to grab a lower part of the handrails typically positioned on each side of the platform, and using the step cover as a climbing ramp means that provides sufficient support adherence under their running shoes for relatively easily climbing the ladder. 
         [0007]    Thus, there is a need for an improved automatic safety pool ladder for above-ground swimming pools. In a broad aspect, the present invention provides such an improved automatic safety pool ladder that avoids the aforementioned disadvantages. 
       SUMMARY OF THE INVENTION 
       [0008]    In a broad aspect, the present invention provides an improved automatic safety pool ladder for an above-ground swimming pool. The swimming pool defines a pool wall extending upwardly above ground, a pool bottom and a pool peripheral ground extending substantially adjacently around the pool wall. 
         [0009]    According to an embodiment of the present invention, the automatic safety pool ladder generally comprises a stationary ladder assembly and a rotative ladder assembly. 
         [0010]    The stationary ladder assembly includes a pair of ladder side members. Each one in the pair of ladder side members has substantially an open trapezoidal configuration defined by a substantially vertically extending ladder side in-pool leg portion and a substantially vertically extending ladder side ground engaging leg portion, that are joined through the upper ends thereof by a ladder side apex portion extending therebetween. 
         [0011]    Each one in the pair of ladder side members is disposed in a parallelly spaced apart relationship relative to the other one, with a ladder platform extending between the ladder side apex portions thereof, and a set of stationary ladder step members extending horizontally between the pair of ladder side in-pool leg portion, and disposed in an equidistantly spaced apart relationship therealong. 
         [0012]    The rotative ladder assembly includes a set of rotative rungs fixed in guide holes inside the pair of ladder side members. A spring is placed on the bottom of one of the ladder side to hold the mechanism in secure position. 
         [0013]    When in closed position, rungs forms a flat surface, preventing climbing. 
         [0014]    Each ladder assembly step member is joined in a parallelly spaced apart relationship relative to the other ones through a rod extending parallelly between each adjacent ends thereof, this rod fixed to a lever permitting controlled rotation. The lever end is placed along the platform, out of the reach of children. 
         [0015]    Hence, when the lever is pulled down in the ladder deployed position, a user standing on the pool peripheral ground can climb the safety pool ladder. 
         [0016]    The weight of users is enough to let the rungs stay in open position, permitting to climb to the top platform without being preoccupied with the lever. 
         [0017]    Then, without weight on any rung, the spring let the lever to be automatically released in normal position, letting reset all rungs in flat position. 
         [0018]    When the lever is released in the ladder retracted position, a user standing on the pool peripheral ground is prevented from climbing the safety pool ladder. 
         [0019]    Thus, the automatic safety pool ladder for above-ground swimming pools of the present invention is relatively stable during strong winds, requires only limited space to be functional, is more likely to be aesthetically appealing among pool side design furniture and, most importantly, may discourage very determined young kids from accessing an unattended above-ground swimming pool. 
         [0020]    Other advantages, novel features and alternate embodiments of the present invention will be more apparent from the following drawings and detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1 , in a perspective view, illustrates an embodiment of an automatic safety pool ladder, according to the present invention; 
           [0022]      FIG. 2 , in a perspective view, illustrates an automatic safety pool ladder, here shown in a retracted position; 
           [0023]      FIG. 3 , in a partial, side cross-sectional view, illustrates an embodiment of a rotative ladder assembly, here shown with the rotative ladder assembly (rungs) moved in its retracted position; 
           [0024]      FIG. 4 , in a partial, side cross-sectional view, illustrates another embodiment of a retractable ladder assembly, here shown with the rotative ladder assembly (rungs) moved to its open position; 
           [0025]      FIG. 5 , in a partial, front elevational view, illustrates the rotative ladder assembly in  FIG. 3 ; 
           [0026]      FIG. 6 , in a partial side cross-sectional view, illustrates the rotative ladder assembly in  FIG. 3 , here shown provided with a lock means for locking the rotative ladder assembly in a retracted position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]      FIG. 1  illustrates various aspects of an embodiment, according to the present invention, of a safety pool ladder  10  for an above-ground swimming pool  12 . 
         [0028]    The swimming pool  12  defines a pool wall  14  extending upwardly above ground  16 , a pool bottom  18  and a pool peripheral ground  20  extending substantially adjacently around the pool wall  14 . 
         [0029]    Now referring more particularly to  FIGS. 1 and 2  respectively, the safety pool ladder  10  generally comprises a stationary ladder assembly  22  and a rotative ladder steps assembly  24 . 
         [0030]    The stationary ladder assembly  22  has substantially an open trapezoidal configuration defined by a substantially vertically extending ladder side in-pool leg portion  28  and a substantially vertically extending ladder side ground engaging leg portion  30 , that are joined through the upper ends thereof by a ladder side apex portion  32  extending therebetween. 
         [0031]    Each one in the pair of ladder side members  22  is disposed in a parallelly spaced apart relationship relative to the other one. 
         [0032]    The stationary ladder assembly  22  further includes a ladder platform  34  extending horizontally between the ladder side members and substantially adjacently the ladder side apex portions  32  thereof. 
         [0033]    The stationary ladder assembly  22  further includes a set of stationary ladder step members  36  extending horizontally between the pair of ladder side in-pool leg portions  28 , and disposed in an equidistantly spaced apart relationship therealong. 
         [0034]    Furthermore, the stationary ladder assembly  22  defines an underside trapezoidal outline  38  substantially circumscribed by the parallelly extending ladder side in-pool leg portions  28 , the platform  34 , and the parallelly extending ladder side ground engaging leg portions  30 . 
         [0035]    The rotative step ladder  24  has substantially a parallelepiped shape. 
         [0036]    In addition, a protrusive rotation axis  40  is placed on each side of the steps  24  and fits into the lateral leg portions  30 . 
         [0037]    Another control axis  41  is placed on one of the sides of the steps  24  and is inserted into the guide rod  42 , this one is placed inside one of the leg portion  30 . 
         [0038]    The guide rod  42  is pierced at equal distance to allow the insertion of control axis  41  of each step  24 , allowing steps to be fixed by their control axis  41  equidistantly and leave no opening between each of the steps when in retracted position. It also allows maneuvering all the steps in unison. 
         [0039]    Furthermore, this guide rod  42  is connected by a pivot  44  to the lever  43 . This lever  43  protrudes on the top side of the ladder side apex portion  32 . 
         [0040]    This lever  43  stands normally in a vertical position when in retracted position. When the user lowers a few degrees the lever  43 , its drag along the guide rod  42  by moving the series of steps in their open position, which allows the user to ascend or descend. 
         [0041]    Furthermore, control axis  41  are retained in good place in their displacement by lunar-shaped slots  31  in the lateral leg portion  30  who receive the mechanism. 
         [0042]    Also, this guide rod  42  is connected to a compression spring  45  which allows to retain the steps in their retracted position. This spring is strong enough to hold up steps closed, but enough relaxed to not cause too much tension on the lever  43 . 
         [0043]    Hence, when the rotative ladder assembly  10  is in the ladder deployed position as illustrated in  FIG. 1 , a user standing on the pool peripheral ground  20  can climb the safety pool ladder  10 . And when the rotative ladder assembly  60  is in the ladder retracted position as illustrated in  FIG. 2 , a user standing on the pool peripheral ground  20  is prevented from climbing the safety pool ladder  10 . 
         [0044]    As illustrated in  FIG. 1 , the safety pool ladder  10  is sufficiently sized and shaped for substantially stably standing over the pool wall  14  in a saddle-like configuration, with a lower end of the ladder side in-pool leg portions  28  resting on the pool bottom  18 , and a lower end of the ladder side ground engaging leg portions  30  resting on the pool peripheral ground  20 . 
         [0045]    In some embodiments, as illustrated in  FIG. 6 , the safety pool ladder  10  further includes a lock means  120  along the lever  43 , for locking the rotative ladder assembly  10  substantially in the retracted position. 
         [0046]    For example, the lock means  120  may define a padlock aperture  66  configured and sized for engaging a locking member  121  of a padlock. The padlock aperture  66  may fit exactly through a side portion of a second padlock aperture that is suitably fixed on the platform  34  so as to block the movement of the lever  43 , consequently to the rotative ladder assembly. 
         [0047]    As would be obvious to someone familiar with locking means for slidable assemblies, such as doors and the like, other known types and arrangements for a locking means  120  are also possible. 
         [0048]    In some embodiments, as illustrated in  FIG. 1 , the ladder side apex portion  32  of each one in the pair of ladder side members  30  is extending relatively higher than the platform  34  so as to define a pair of substantially rigid pool ladder side guardrails for safely helping users move across the platform  34 . 
         [0049]    In some embodiments, as best illustrated in  FIGS. 1 and 2 , the set of stationary ladder step members  36  has a substantially equivalent number of step members relative to the set of ladder assembly step members  24 . 
         [0050]    Although the above description contains many specificities, these should not be construed as limitations on the scope of the invention but is merely representative of the presently preferred embodiments of this invention.

Summary:
The present invention relates to an automatic safety pool ladder for an above-ground swimming pool composed of a set of rotative self-closing steps where the retracted position prevents access to water and where access to open steps is easily controlled by user through a lever arm and positioned so that the arm is not accessible to children.