Patent Publication Number: US-2010122406-A1

Title: Pneumatic powered lift for swimming pools

Description:
The main subject matter of this patent of invention is a PNEUMATIC POWERED LIFT FOR SWIMMING POOLS especially created for people with motor disabilities and/or people in wheelchairs to get in and out of swimming pools, thus discarding the usual difficulties and inconveniences to be expected when they wish to take a bath, either for therapeutic reasons or for the sake of recreation. 
     More specifically, this invention patent refers to a very specific lift for swimming pools, which comprises a receiving platform that may be placed above water level, preferably coplanar to the pool&#39;s edge surface and may remain stable over it, thus providing an essentially flat and horizontal surface where a person remains, either standing or seating on a chair, or even sitting directly on this platform. 
     These lifts were designed for handicapped as well as elderly people in general, either in physical and therapeutic treatment institutions and centers or in clubs and recreation venues. 
     In order to lift and lower such receiving platform, various inventions have been developed, many of which are patented, for different construction and functional conceptions, seeking to make it easier to use, avoid unnecessary risks, lower costs and, mainly, achieve the greatest efficiency possible. 
     This invention in particular is an extremely simple device that can be operated either by a third party or users themselves (through a remote control). It stands out because it is operated by a pair of pneumatic cylinders especially placed in the same general support structure of the device; thus taking great advantage of its operative capacity while simplifying its assembly and maintenance tasks. 
     This invention defines a new combination of means designed to achieve a superior result, therefore, it is rendered unpredictable and surprising even for a field expert. Consequently, it is not only new, but also its construction and functional conception shows a clear inventive activity, therefore, it meets the conditions required by Law to be considered an invention patent. 
     PRIOR ART 
     The existence of numerous Rehabilitation Centers and Public and Private Institutions specialized in therapeutic treatment for the elderly people or for people who have lost the ability to move by their own means is common knowledge. 
     The role of the forenamed rehabilitation centers is to provide special treatments, physical activity oriented in order to activate the overall functioning of the body, whether for its recovery or to avoid malfunctions caused by lack of physical activity. 
     Hydrotherapy is a relevant aspect taken into account in the different recovery methods. Hence, in most cases the aforementioned Institutions are equipped with swimming pools. 
     Many of these special swimming pools usually have a construction condition adapted for handicapped people, such as handrails adjacent to the entry and exit sectors, or receiving platforms that can be lowered and lifted into the water body in a controlled way. 
     However, efficient solutions have not been found for every problem that may arise. 
     For instance, for safety reasons, and due to the risk and danger it implies, the use of electrical resources to operate devices in water areas is not advisable. Therefore, access with electrically driven chairs and electrically powered lifts is thereby avoided. 
     Similarly, the use of hydraulic lifts is currently non-advisable since there is risk of contaminating the water with these devices&#39; oil. 
     As a result, throughout the years, there have been many inventions which display submergible and emergible platforms attached to different types of assembly structures, combined with different operation resources, among which we shall name the following: 
     Application for Argentine Invention Patent P 050102866 from Mr. Carlos Alberto SORS. It refers to a floating platform, submergible and emergible by means of pneumatic action to be used in swimming pools. This invention can be placed over the water body of a swimming pool or similar, and can work as a receiving platform so that a person, placed over it, may access and submerge into the water as a consequence of lowering vertical movements, and then emerge by means of the lifting operation executed by the platform in such body of water. In this case, the aforementioned submersible platform is a hollow, light and rigid casing with an upper horizontal floor, where downward-oriented lateral walls are projected (when into the water), thus defining an internal enclosure which remains communicated with the exterior through at least one air exit and entry duct cause the ascending and descending vertical movements of such platform in the body of water; these movements are guided by vertical logs placed adjacent to the inner side of the pool wall, whereby the corresponding sliding carts projected from the platform move. 
     In this invention, an internal and watertight enclosure is define which holds a certain air volume with sinking resistance; therefore, the platform remains floating on the water surface, even when a load similar to the weight of a person is placed on it. 
     Provided the air volume retained inside the aforementioned enclosure is released, the weight supported by the platform will eventually overcome the resistance force and start submerging into the body of water. 
     For this purpose, in a likely implementation, the invented device includes, communicated to the abovementioned internal enclosure, an outwardly-projected tube for air exit where a valve closure that opens or closes the established communication is included. 
     The same internal enclosure may remain communicated to a tubular duct that extends to an air supply source placed duly far from the swimming pool, so that the reverse process is conducted through it; that is to say, the air inlets into such internal enclosure creating an internal pneumatic pressure that causes a lifting force which, when it overcomes the cargo weight supported, will translate into rising the platform. 
     The problem of this innovative invention lies in ensuring the due control of lifting and lowering movements since many times the presence of some undesired air bubble creates sudden “leaps” that affect the needed movement softness required in many cases. 
     On the other hand, many times the water surface is below the edge of the pool, in a significant height dimension, thus hindering the access of user to the platform, especially in the case of elderly, handicapped or people in wheelchairs. 
     Invention Patent DE 3.708.117 from Mr. Joerg HECK. It refers to a device suitable to be installed on the edge of a swimming pool, holding a hook system to support a wheelchair projected, cantilevered, towards the interior of the swimming pool. These supports are attached to a vertically elongated center post which moves vertically to lower and lift the chair, which is operated with a manually operated rotating handle. 
     There are several limitations in this case, namely the fact that not all chairs can be submersed into water; therefore, in order to be able to use this invention, users shall have specific wheelchairs. Moreover, the rotating handle that commands the movements is external so that users must always be aided by a third party. 
     Application for Invention Patent 200302466—Publication ES 2.253.953 from Mr. Joaquin Lioveras Macía and other. It refers to an invention entitled Swimming Pool Immersion System. This invention can be used by handicapped people and can be operated by users themselves. This invention stands out as it uses an innovative hydraulic cylinder placed, submerged in the water body, assembled in the bottom of the swimming pool and is activated with tap water. 
     While it enjoys some advantages in terms of its lower maintenance and installation cost, it fails to be powerful; therefore, whenever the weight of user is heavier than usual, its operation is non-acceptable. 
     Utility Model in Spain, Publication 1050637 from Mr. Jaime MORRAL GISPERT, entitled “Device For Entering Handicapped People in Wheelchairs Into Swimming Pools”. 
     It comprises an innovative platform with handrail radially mounted to a vertically mobile support, which revolves by manual operation. This support is linked to a hydraulic cylinder that slides along a vertical axis assembled to a support column that is supported on the bottom of the swimming pool through by lower end, whereas by its upper end it is linked to a frame installed adjacent to the edge of the swimming pool. 
     As indicated hereinbefore, this invention uses a hydraulic cylinder that makes contact with the swimming pool water body. Therefore, necessary safekeeping measures have to be taken in order to preserve the normal performance of the hydraulic system, thus avoiding any possibility of oil leak, which leads to large installation and maintenance expenses. 
     U.S. Pat. No. 5,685,030 from Mr. Edwin Baranowski, entitled Lift that Enables Someone in a Wheelchair Into and Out Of a Swimming Pool or Water Body. 
     In this case, the wheelchair is also secured to a support plate, placed on the upper end of the piston of a hydraulic cylinder which must remain submerged in the water. The piston&#39;s upward and downward movements are operated from an external pusher engine communicated through ducts, thus creating a double-effect hydraulic circuit. 
     A hydraulic cylinder immersed in the pool&#39;s body of water is also used, which requires safekeeping measures in order to preserve the regular performance of the hydraulic system, thus increasing installation and maintenance costs. 
     United States Patent (Publication US 20067/0101568 A1 from Mr. Martin Gallen, entitled “Swimming Pool Lift”. This invention refers to a very special assembly which includes a solid hydraulic cylinder whose cylindrical body supports a chair with seatbelts created to secure the use when sitting in this chair. This cylindrical body can be rotated 180° to allow the user to ingress and egress from the lift. Similarly, the hydraulic cylinder is assembled in such a way that it can be moved vertically when lifting and lowering a user. 
     The published device requires a complex and delicate installation due to safety and functional reasons. 
     U.S. Pat. No. 5,960,909 from Mr. Stefan Horcher and other entitled Device for Lifting a Person from a Swimming Pool. This invention refers to a carrier structure with a lower end submergible in the body of water and which has a manual holder. This structure is attached to a vertical jack mechanism assembled to a vertical column, operated from an external lever. 
     It is a specific device not suitable to lower persons in wheelchairs, elderly or disabled people. 
     The Application for French Invention Patent N o  82 01472 from Mr. Jacques CLODUNG, entitled Lift for Enabling Handicapped People into a Swimming Pool. It refers to a platform with a handrail designed to receive the user, which is placed adjacent to the edge of the swimming pool in order to move vertically towards the bottom of the pool. This platform is attached to a counterweight through a system of cords across pulleys which limit the lowering speed of the user who gets into the pool. 
     U.S. Pat. No. 4,104,082 from Mr. Claude Boujard and other entitled Lifting Device to Be Used in a Liquid Medium. It refers to a structure that holds a flat platform supported by a pair of parallel arms, which can be placed in two operating upper and lower positions, keeping such platform in horizontal position. 
     This device can make the aforementioned platform access and exit the body of water while holding a person or equivalent in weight. 
     DESCRIPTION OF INVENTION 
     None of the before mentioned resources, apparatuses and devices informs or suggests the construction and functional principle of the lift referred to herein this invention patent, which resources to the use of a special pair of pneumatic cylinders operated from a small compressor that, in a preferred implementation, can amount to 220 liters/min. with a capacity of about 50 Lts. 
     Indeed, the invented lift stands out as it uses pneumatic cylinders that, in general, are smaller than most hydraulic cylinders, as well as silent, extremely neat and non-contaminating, with the special feature that they make out the upper section of a pair of vertical cylindrical center posts that are part of the lift&#39;s support and bearing structure. 
     Indeed, the aforementioned tubular vertical center posts may be extended adjacent to the pool&#39;s wall and be supported on it until reaching the floor&#39;s bottom, thus being the lift&#39;s support structural parameter while working as guide of the movements of the platform where the user stands or sits. 
     A special structure is thereby constituted where the presence of such main parallel center posts pointing upwards from the bottom of the pool, thus exceeding the height of the pool&#39;s edge, is a remarkable feature. 
     Under the conditions hereby described, the pistons from both pneumatic actors slide along the upper sections of their respective cylinders, defined over the pool&#39;s edge level, thus preventing any possibility of their becoming into contact with water from the beginning and ensuring a simpler maintenance and longer life for their lifting and lowering operations. 
     Both pistons extend their respective piston rods that slide vertically in the interior of such cylindrical center posts, attached to the user&#39;s receiving platform, in such a way that the platform can slide vertically from the pool&#39;s edge to its bottom. 
     Since it is a pneumatic powered device, assembly already explained, the platform&#39;s movement can be interrupted immediately, at any point, whether while submerged or outside the water. This functional feature is extremely distinctive in comparison to many other known similar devices, in which the platform&#39;s operation interruption usually leads to undesired movements which alter the necessary stability required in some cases. 
     In the correct way, the platform may be placed adjacent to the pool&#39;s edge even when the surface of the body of water is way below such level. 
     The lift&#39;s entire operation is controlled from a small control board located externally for the easy access of any user. It has a corresponding manually operated knob through which all movements are controlled. 
     The invention makes sure that the valve resources from the pneumatic operation circuit may be electronically operated. In this case, they may be operated from a remote and portable control commanded by users themselves from the platform, inside the pool. 
     Inventive Activity 
     No lifting apparatus or device for pools currently known proposes or even suggests the construction solution that the aforementioned paragraphs describe. Hence, this proposal is not only innovative but has also a clear inventive activity. 
    
    
     
       SUMMARIZED DESCRIPTION OF FIGURES 
       In order to summarize the advantages referred to herein and further advantages users and experts on the field may add, and so as to facilitate the understanding of the construction, constitutive and functional features of the invented lift, a preferred embodiment of implementation is described hereinafter which is illustrated, schematically and with no determined scale, in the plates attached. It is hereby expressly stated that, being precisely an embodiment, no limit or exclusive feature to the protection scope of this present invention patent shall be allocated, on the contrary, it is only aimed at explaining and illustrating the basic concept this invention is based on. 
         FIG. 1  is a view plane in perspective which shows a lift that corresponds to construction and functional conditions under the present invention patent. Such lift is placed in a pool, with its receiving platform outside the water surface. 
         FIG. 2  is a view plane in perspective, similar to the one represented in the previous figure; in this case, its receiving platform is shown submerged in the body of water. 
         FIG. 3  is a vertical cut view plane of the same lift from the previous figures which, in this case, shows the position of its parts and pieces when its receiving platform is placed in two operating positions. 
         FIG. 4  is a broadened description which represents a construction aspect related to the assembly of the receiving platform in its support structure center posts. 
     
    
    
     It is hereby made clear that, in every figure, the same reference numbers and letters there correspond the same or equivalent parts or constitutive elements part of the whole, according to the embodiment selected for the explanation of the invented lift. 
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     As shown in  FIGS. 1 and 2 , the pneumatic powered lift for swimming pools referred to in this invention patent is made up of a pair of parallel vertical center posts ( 1 ) and ( 2 ) with an upper section projected upwards, to a significant height, above the level of the swimming pool edge (P), and a lower section that extends up to the bottom&#39;s floor of the same swimming pool, so that a large section of its length remains immersed in the body of water (A). 
     Both vertical center posts are part of a supporting structure that is completed by the fixed handrails ( 3 ) and ( 4 ), which lower seat sections ( 5 ) and ( 6 ) are provided for the assembly and fixing of the unit in accordance to the swimming pool edge. 
     As previously explained, the aforementioned vertical centre posts are straight cylinders preferably made of stainless steel or any similar water resistant material, with a sufficient structural capacity as to support the weight of the load being transported. 
     Both centre posts, in their middle and lower sections, have vertical guide slots ( 7 ) and ( 8 ) which guide the upward and downward movements of the receptive platform ( 9 ), with a pair of tubular handrails attached ( 10 ) and ( 11 ), which, for design purposes, may be of the same height and format as the aforementioned fixed handrails ( 3 ) and ( 4 ). 
     As shown in the cut away view in  FIG. 3 , the superior upper section of said vertical centre posts ( 1 ) and ( 2 ) runs from the free extreme ( 12 ) and ( 13 ) to the beginning of the mentioned guide slots ( 7 ) and ( 8 ), constituting two actuator pneumatic cylinders through which the platform movements ( 9 ) are performed and commanded. 
     It is a particular construction and functional solution aimed at achieving a special format and layout of the centre posts so that they can be used in the assembly of the propellant resource that, if properly protected and isolated, away from the abrasive water, simplifies the task of moving the receptive platform directly and with minimum wearing. 
     Indeed,  FIG. 3  shows that the upper section of each centre post shapes a respective double effect pneumatic cylinder, and so an internal chamber is established ( 14 ) closed by the plugs ( 15 ) and ( 16 ), where a piston moves ( 17 ) activated by the action of the pneumatic pressure circulating through the inlet and outlet fluid ducts ( 18 ) and ( 19 ) with the insertion of the corresponding valves at intervals (not illustrated) placed in the control board ( 20 ) from where the corresponding pipe, that comes from the pneumatic compressor, extends, not illustrated. 
     The command will allow for either electronic resources driven by digital means through manually operated knobs, or even by a remote control with the advantage that in this case it is users themselves who command its movements. 
     The construction solution designed for the assembly of said receiving platform ( 9 ) so that it can perform its upwards and downwards movements effectively, without difficulties stands out. 
       FIG. 3  also shows that a piston rod extends ( 21 ) from the piston ( 17 ) which is located within the center post projected downwards until it attaches to a metal plate ( 22 ) upon which the supporting structure of the mentioned platform is mounted ( 9 ). This structure juts out through said vertical slot ( 7 ) or ( 8 ) on the lower section of each center post. 
       FIG. 3  also shows that in order to ensure the stability in the assembly of said platform ( 9 ), the aforementioned lateral connected handrails ( 10 ) and ( 11 ), are attached to the same supporting structure and they also support the referred piston rod ( 21 ) by means of a metal plate ( 23 ) located at a higher level. 
     Finally,  FIG. 4  illustrates a construction solution incorporated to the platform assembly regarding the piston rod that extends within the lower section of the cylinder&#39;s interior. It is depicted that the fixing of the assembly must be performed in the interior of the cylindrical center post; for this purpose the respective openings ( 24 ), ( 25 ) and ( 26 ) are made to allow the passage of manual adjustment tools to fasten the plate ( 22 ) and the point ( 23 ). 
     It can be observed that once the assembly is carried out, the use of a fixed protection lid is considered ( 27 ) that closes the assembly and prevents accidents during operation.