Patent Grant
8418411
The present invention refers to an integral, industrialized, modular dwelling system which is based on modular, multi-functional, three-dimensional modules that are made from reinforced concrete, thus optimizing its earthquake-resistant, monolithic structure, through ribs and cells in walls and slabs. The coverings and mezzanines use a “Structural Geometry” and Vaults. A variety of very high esthetical and social sets are achieved, and having superior durability.
In the system of the invention, the manufacture of modules, coverings and components is performed at a semi-automated covered plant, integrating finishes, installations, accessories, metal work, partitions and high quality details. They are afterwards shipped to site already for being assembled, thus creating single-level dwellings or several floor buildings.
The integral, Industrialized, Modular dwelling system which is intended to be used for serial dwelling construction has no comparison to any of the current constructive systems, in that the concrete dwelling construction by the present invention is done either in situ using metallic molds or producing at the plant prefabricated panels which are assembled on-site in order to form the dwellings' walls and slabs.
The integral, industrialized, modular dwelling system of the present invention has the feature that in a plant or factory building, complete rooms having floor and walls are prefabricated from a steel mold actuated by means of hydraulic jacks such that with the use of a steam curing four castings are achieved within 24 hours, as opposed to the traditional mold system for on-site casting, wherein a casting is achieved every 24 hours. Fixtures, finishes and metal work can be integrated on factory, such that on the construction-site, the working is reduced to connections between rooms of the dwellings and their roofs.
The complete rooms will be assembled on-site by “dry” connections based on screwed joints; as opposed to the traditional panel-based prefabricated systems in which the joints are “wet” that is based on small castings, further in the traditional systems the panels are sent without finishes, the fixtures are made on-site as well as the metal work.
In the present integral, industrialized, modular dwelling system, as opposed to the existing constructive systems, modules are produced which include all the elements (structure, finishes, wood finishing, etc.) having a superior quality, thus saving 80% manpower and the construction time is speeded up to 70%.
By performing the manufacture process inside a closed plant, work can be done at any time of the year, with any weather, having the guaranteed production under control and with the highest quality.
From a formal point of view, the current dwelling edification systems are rigid and repetitive, thus falling into an esthetical monotony with no individuality. The integral, industrialized, modular dwelling system of the present invention, on the contrary, humanizes the dwelling due to the huge variety of components that are produces at the factory, these can be exchanged resulting in countless formal options, of textures and color, thus giving the individuality each dwelling requires.
In the current systems there is a need for further afterward working in order to install the finishes, the integral, industrialized, modular dwelling system allows to obtain every kind of textures and integral colors without additional on-site working.
Currently, in the commonly used systems, there is a need for constant maintenance in order for the finishes to preserve their original features. With the present integral, industrialized, modular dwelling system, by being integral finishes there is no need for maintenance work and their durability is for the house entire useful life.
The future growth of dwellings is very expensive and complex, thus creating every kind of social and urban image problems. The integral, industrialized, modular dwelling system allows the owners to place an order for the module they need, the modules being delivered complete either they are residential (habitable) or technical (restrooms) and are assembled at a three hour time period, which makes them completely unique.
In the following there is a description of some of the constructive systems which are most commonly used nowadays and it follows a brief comparison thereof with the system object of the present invention.
Block Walls
The construction of block walls is a process wherein manually and on-site said walls are gradually constructed from small concrete masonry pieces which are joined with mortar.
With the integral, industrialized, modular dwelling system of the present invention, the work is moved to the factory and with the mold casting processes, the construction of said walls is reduced from a week to a period of three to four hours, with millimetric tolerances in its execution. The concrete and steel used with this system are similar to those of the block walls but with an important reduction in the execution times and at a substantial increase of the execution quality.
On-Site Cast Concrete Walls
Poured concrete walls are solid walls which require a centering or formwork that is gradually moved at the construction-site for the walls' casting.
With the integral, industrialized, modular dwelling system object of the present invention, hollow walls can be constructed thus achieving concrete savings of up to 40% without reducing the wall's strength and with dimensional tolerances of tenths of a millimeter. Further, the integral, industrialized, modular dwelling system produces concrete of several colors and textures with which integral finishes are obtained. The textures are applied in different ways from the centering with factory quality.
On-Site Cast Concrete Slabs
On-site cast concrete slabs are solid having a 10 cm normal thickness, which need several days for their shoring to be removed after casting.
In the integral, industrialized, modular dwelling system object of the present invention the slabs (foundation and roofing) are prefabricated having a domed and ribbed structure. For them use is made of Structural Geometry, which allows concrete savings of up to 40% and due to the mold manufacturing process an apparent finish which needs no gypsum or tyrol layer application is achieved. A slab of this kind is self contained and needs no waiting time after its installation, and further when being manufactured the curing is done with a heating system, which renders it much more fast.
Joist and Flooring Block Slabs
These slabs require joists, block slabs and on-site casting of a concrete compression layer, the main difference with the slabs of the integral, industrialized, modular dwelling system of the present invention being that in the latter the material equivalent to the flooring slab is saved and by being prefabricated members and apparent finish is achieved that, as opposed to joist and flooring slab needs no additional finishing work.
The core principle of the present invention system is to significantly reduce the concrete, steel and manpower used in dwelling construction, as well as to reduce manufacturing time, thus guaranteeing a high quality and millimetric precision with integral finishes, prefabricated fixtures and standardized components. The peculiar features of the modules are among others their structural multifunctionality (thickness variation and cells in walls), lego type modulation, facility concentration, functional space generation, architectural detail variation, slab-flooring dual function, and the variability of the structural geometry vaults. The urban components are produced with the same criterion of “structural air” always reducing material consumption.
It is therefore an object of the present invention a concrete module factory for manufacturing high quality and high durability economical dwellings.
It is another object of the present invention an industrialized process for constructing a series of concrete three-dimensional modules of a residential and technical character for manufacturing dwellings.
Other object of the invention is to provide a flexible mold for manufacturing three-dimensional modules of residential and technical character for building dwellings.
Another object of the present invention is a method for in situ edification of dwellings based on prefabricated concrete three-dimensional modules.
All the abovementioned objects of the invention jointly make up a single inventive concept grouped by the overall concept of integral, industrialized dwelling system.
These and other objects which will be apparent are now disclosed and illustrated in the figures accompanying this specification.
The invention shall be disclosed in detail with reference to the drawings, in which:
House manufacturing is made up by high tech equipment, thus reaching the highest levels of precision, quality and cost. Its backbone is constituted on one side by the mechanic actuation steel molds both for boundaries, metallic brushes (conical elements) with unique design for constructing three-dimensional modules with honeycomb and ribbed walls, as well as vaulted slabs having varying thickness and shapes thus creating high flexibility in their combination, and on other side, the special concrete production system for achieving surfaces and constructive details, as well as the peripheral equipment for cutting, enabling and soldering. The use of platforms allows an optimal handling of the modules as it avoids extraordinary efforts in the structures of the concrete curing process. Also, this process is enhanced by integrating curing chambers. The modules are connected each other by bridle joints in slabs and walls, which allows an easy on-site assembly, dispensing with construction works on-site, and thus creating a system free from assemblies and screwed joints.
The originality and novelty of the present invention system consists of achieving three-dimensional modules with monolithically cast walls and slabs having void cells thus optimizing their assemblies and using the same molds for constructing buildings. Another novel aspect is the integration of modular and varying dwelling solutions, as well as for urbanization and equipment.
The system also features a great variety of shapes, textures and colors, having infinite combinations, thus obtaining human individuality in an industrialized system.
According to the overall concept of the integral, industrialized, modular dwelling system object of the present invention, concrete savings of up to 40% are achieved by substituting it with air as it is monolithically manufactured. This is achieved in part by using an arch center designed for creating cells in the concrete walls, according to the structural needs and which likewise allows to augment the walls' thickness and the module's width.
The overall concept of the invention can be summarized by the following sequence of steps illustrated in
i) Assembly and installation of the inner retractable mold 8;
ii) Deployment of boundaries forming the outer mold 7;
iii) Placement of combs 6 at convenient distances in the gap formed between the inner mold 8 and the outer mold 7;
iv) Concrete casting into the gap formed between the inner 8 and outer 7 molds;
v) Curing of the molds 9;
vi) Finishes integration and final finishing 14;
vii) Shipping of modules to the construction-site 17;
viii) Deployment of modules on their site 22;
ix) Joining of modules 26.
Production Process Synthesis
The module production process is done by the following sequence of steps:
House manufacturing is a new concept of concrete prefabricated production that allows a production of 40 dwellings a day and 10,000 dwellings a year. The factory backbone is made up by an integral system of production, curing, finishing and stacking areas, modern high precision equipment, production, quality and organization control systems, and a logistics system for performing a production in carrousel system.
Each module (Residential and Technical), component or element is prefabricated into a system of multifunctional and flexible molds having very high geometrical precision of ±1.5 mm, integrating variable shapes of novel and esthetical textures by using integral or exterior color, which is made possible thanks to the use of autocompressible concrete (SCC). By means of a special pumping system in said modules, which is done from bottom to top and by using an adequate filling rate, elimination of air and realization of a fine surface finish are achieved. For flat members, the casting is done in the traditional way.
Concrete plant 3 is provided with planetary mixers and is the supplier of the autocompressible concrete at a high quality and mixture blending, including color. Concrete loads are cast therein into a hopper for homogenizing them and allowing their uniform distribution at pumping.
In the continuation of the carrousel system, the next step of the process is the ingress to the area on which the modules detail and finishes preparation is performed. In this area the preparation 10, integration of fittings in furniture 11, prefabricated components 12 and painting 13 take place. The activities are done by working teams, thus avoiding interference by dividing into zones or groups. Working islets gather the installing and testing tools and equipment for achieving the final finishing. Once the final finishing is concluded, the platforms are shifted with the prefabricated products towards the storage and/or assembly zone 16 for being sent to the construction-site.
Factory Production Process
As can be seen in
It then takes place the uncentering of outer boundaries 7 and of the retractable inner mold 8 and the mold cores. Then the already uncentered cast modules are transported by mobile platforms driven by a wheel and track mobile system which allows lateral and longitudinal movements, thereby preventing warping or over-strains in the prefabricated products. In the final curing area 9 the final curing step lasts between 6 and 8 hours. Continuing with the process, the following step consists in entering the area on which the modules detail and finishing preparation take place. In this area it is proceeded to the preparation 10, furniture accessories integration 11, prefabricated components 12, painting 13 and final finishing 14. Once the final finishing 14 has concluded, the platforms with the prefabricated products are moved to the storage 15 and/or assembly 16 zone for being sent to the construction-site 17.
Module Construction Process
As can be seen from
a) Placing the slab centering 51;
b) Placing the laths and steel reinforcements 2 for slab and walls together with the installations;
c) Lowering the inner centering 8 such that it is seated around the slab centering 51 and inside the laths and steel reinforcements 2;
d) Expanding the inner centering 8 until it reaches the inner area intended for the module;
e) Placing the boundaries 7 of the outer centering, leaving a free gap between said boundaries 7 and the inner centering 8 corresponding to the intended thickness of the module wall;
f) Lowering said combs 6 such that they are loosely placed between the inner centering 8 and the boundaries of the outer centering 7, in order to create the air gaps at the time the module casting is done;
g) Pouring the concrete after said combs 6 are down at the intended position;
h) Removing the outer centering 7 when the desired set is achieved;
i) Rising said combs 6 for leaving free the honeycomb gaps formed during casting;
j) Retracting the inner centering 8 to separate it from the cast module inner wall;
k) Rising the inner centering 8 for leaving free the inside of the cast module;
l) Passing the finished module having an integral finish at the floors, to the set area;
m) Leaving the concrete to set and afterwards continuing the cast and set module travel to the installation area;
n) Preparing the details and finishes 10;
o) Integrating the furniture accessories 11;
p) Integrating the prefabricated components 12;
q) Painting the modules 13;
r) Effecting the modules final finishing 14.
Once the manufacturing process has ended, the already finished module is raised to the mobile platform 17 that will carry it to the construction-site, wherein a crane 21 shall place it at its final destination.
Construction Process Elements
It follows a detailed disclosure of the elements used in the factory production process.
Molds
The first elements to be considered are the molds, which are made of 8 mm steel sheeting which has been designed with the maximum structural efficiency. Its geometry allows to achieve a high finishing precision. The use of this material allows to obtain the high quality needed by the houses made of the integral, industrialized, modular dwelling system of the present invention. When a new mold is designed in the computer, the electronic data is transferred to a novel laser cutting machine. The operator here only controls the cutting process. This machine guarantees a precision of ±0.01 mm in the mold construction.
In the system of the present invention, the element that can be considered as the most important one and which allows the great flexibility and versatility of the system is a flexible mold which is used for casting monolithic concrete modules with the flexibility of being able to reduce the amount of material by a mechanic system that actuates some metallic cone-shaped combs which are located, as the structural needs require, inside the mold for being towed after casting, thus leaving cells inside the concrete volume.
The flexible mold is an integral system that can be adapted to the most varying module requirements, adjustable in every direction, length, width, height, thickness and comb amount and location.
Said flexible mold consists of:
(a) A retractable mold 8 suspended in a frame, which moves downwards and upwards thus working as an internal centering.
(b) An outer mold 7, divided in boundaries, which works as outer centering.
(c) A basket or frame 52 which, located in the upper part of said molds, works as comb support 6.
(d) A series of slightly tapered combs 6 which will fill in the space inside the mold, for being removed after casting and leaving air voids, thus reducing the amount of material. The amount and position of said combs 6 will be the result of a structural study specifically made for each module composed of different wall shapes, and which will make up the several prototypes.
Laser Cutting System and Metal Bending
The sheet needed for preparing the individual modules is cut by a laser cutting system consisting of a Trumpf Trumatic® series L4030 machine operating according to a traveling optic nozzle principle, in which the laser beam rod is moved over the working area. This allows to achieve very high processing speeds independent from the thickness of the material to be cut. The operator and laser control panels are integrated to the machine structure. There can be accessed from three sides in order to facilitate loading and unloading of material, as well as being able to simultaneously perform these steps in production avoiding dead times. The laser beam is a multifunctional tool, its main feature being to allow cutting a wide variety of materials having different thicknesses with high precision. The geometry of the cuts can be simple or complex because the laser has the capacity of leaving the piece ready for assembling.
Concrete Plant
The mixing plant is fitted with two or three planetary mixers for producing 600 m3/day. This system allows to achieve a high quality concrete for obtaining high resistance and excellent quality surface finishes. With these equipments it is possible to produce Autocompressible Concrete (SCC), which allows to comply with said requirements. Said casting are also performed rapidly and easily. Likewise, it is also possible to comply with the tolerance in the best way as there is no need for the traditional vibration, thus lengthening the service life of the centering while achieving a high quality surface in the finished modules.
Pumping
Two pumps are needed which are connected to the concrete mixing bowl. These pumps are the endless screw kind of pumps. This equipment pumps concrete uniformly without exerting shock forces on it. This is a great advantage for the mold design. The machine is modularly constructed. All of its parts can be exchanged very quickly in case they become damaged. The pump is connected to the lower part of the mold in order to perform the injection from the lower part thereof. This pump-mold connection is mechanical and has a simple operation for performing a uniform dispensing of the whole element.
Production and Preparation of Reinforcing Steel and Meshing
The fully automatized production for producing custom made meshing by using a versatile welding system is the most efficient and economically feasible method for producing the reinforcement of about 23 ton/day and 200 m2/hr. Quality is made possible with the exact positioning of the reinforcing inside the prefabricated product, thus simplifying the logistics for moving said material (perfect deployment and simplification of its positioning). Full compliance of the structural requirements is one of the main arguments in favor of this production method. From the several roll rotors, the machine is automatically fed of cable for automatically straighten and cut it, in order to achieve the required longitudinal and transverse bars regardless of their amount, length or gauge. The rotor-based straightening system has been fully tested and assures the constant processing both of cold and hot rolled materials, thus complying with the most stringent standards, which is a prerequisite for the plant as such (without problems and continuous operation).
A CAD-CAM (Computer assisted design/computer assisted manufacturing) controls the correct location of the bars which is done by a rack system having tongs and which places the transverse and longitudinal bars in the notches that exist on a intermeshed platform for welding the intersections that can be percentage-controlled. This system allows to prevent waste by being exact cuts of the bar length in order to make window and door passages.
The automatic rotable MSR 16 2 BK machine straightens, cuts and bends 4 to 16 mm gauge cold or heat rolled roll bar. The same will produce 15 ton/day.
The machine is designed for fulfilling the needs high production capacity plants demand, for which it is essential to make a rapid diameter change. The special features of this machine make it specially adequate for using in prefabricate production plants and steel preparation plants with a high degree of automation.
Curing
Curing of the cast molds is done in three phases or stages. The first and second 9 curing phases are performed at the very casting area and the third phase is done at the curing chamber or zone. Curing takes place naturally by setting the ambient temperature, taking care of relative humidity and keeping concrete's own heat by using heaters.
In all the concrete curing stages the necessary resistances have to be obtained in order to remove combs 6, drawing cores and removing side wall borders 7 or centering 8. In the first curing stage the resistance must be between 2 and 3 MPa which is necessary for drawing said combs; the second stage has the purpose of achieving sufficient concrete aging (7 MPa resistance) in order for the casting inside the mold to support movement towards the third curing area, this has the purpose for concrete to reach the sufficient maturity (15 MPa) in order for centerings 7 and 8 to be removed from said side walls.
It is necessary to protect the temperature generated by the chemical reaction occurring between cement and water by taking advantage thereof for curing the element. As an additional alternative cores could be heated to a temperature not higher than 40° C. in order for concrete to get higher resistances at early ages. In the tests and experiences that are currently being obtained, a canvas system for keeping temperature is being evaluated, although by the time said elements are introduced to the curing zone, the use of canvas is unnecessary.
From the stationary zone the element is shifted, already been uncentered from the cores and the outer walls, transporting it on the platform which is its base and that shall be kept during its whole travel up to reaching the storing point. In the abovementioned curing stages there is no lifting of the element because all the displacements are horizontal even when entering the standing zone in which it will stand for about 12 hours, the element then being moved to the following zone.
In-Factory Movements by Overhead Cranes
Overhead cranes are composed of steel frames and an adjustable high precision electromechanical engine which guarantees that the loads are always at the system's center of gravity. The capacity of these cranes has been chosen according to the loads to be handled ranging between 5 or 20 ton. Pulley adjustment is done by means of a rigid frame system and an electromechanical crane that can be adjusted in longitudinal position about ±750 mm. Centroidal balance is achieved by adjusting the position of the electromechanically operated charge (transverse) tie and the crane (longitudinal).
The dual rail of overhead cranes offers the lowest dead weight ratio in the system as it is distributes in two bearings the structure weight. They are also characterized by the excellent geometry thus assuring very favorable traveling features. The particularly big towing height is achieved due to the fact that the hook can pass between the main steel frames.
Assembling System
In order to perform the assembly of the elements a 100 ton. hydraulic crane is required. The gin pole or arm of the crane is formed by a structure that gives the adequate resistance for the loads but at the same time allows to have few wind resistance. Towing and lowering can be substantially performed with the aid of the engine although they can also be made with regulated descent and no engine, for all of them a hoist system is used. It has a dampening system which gradually reduces operational speed by avoiding jolting when beginning load towing or lowering.
Installations and Finishes
Preparation works for prefabricating installations need adequate tools, definition of all their elements and material disposition at the site in order to be able to perform rapid and good quality assemblies. All the piping is placed inside the concrete wall before performing the casting. In order to perform the prefabricated installations special scantlings are handled; workers can thus install piping having the corresponding bending and cutting, and afterwards placing the rapid union connections; with this is made possible an installation that can be places with a single movement, as a single element and tested. Preparing the electrical installation must be done directly in the mold. The cases or boxes are fixed by special connectors included in the mold such that their adequate defined position is assured, thus reducing the risk of human errors and speeding up the setting process. The polyduct contains the wiring and is directly attached to the steel structure by using a trolley carrying all the tooling, connectors and material required for making the installation; each of them has a predetermined place inside the trolley for being easily located.
Paint application is done by means of a sprinkler system, this can be achieved because the wall surface finishing is adequate for achieving a uniform application.
Shipping and Deployment at Construction-Site
Technical and housing modules are shipped to the construction-site (or future growth) by trucks with specially designed platforms.
Modules are places on prefabricated foundations, by means of a crane located at the construction-site, for simply assembling the dwellings by screwing the joints, that is by “dry work”.
For future growth the required module is likewise shipped with the difference that the crane is included inside the shipping truck.
Module Placing at Construction-Site
Shipping to the Construction-Site
The element is towed by placing it on the transporting equipment, the covering wall being then placed with the intention of shipping the two elements at the same time and thus reduce transportation and towing costs and in order to simplify the logistics. The transport then heads to the assembly site. For optimizing shipping use is made of feed type equipment, which are two trailers on which the two elements are shipped thereby optimizing travels. At the assembly place there is a Terex 1000 caterpillar track crane which due to its load movement control allows a uniform movement without sudden jolts, likewise, a rocker for the automatic regulation of the loading centroid is used that allows to easily position the element at the desired place; this positioning is guided by bridle joint type connectors which are embedded in the modules forming the dwellings, which serve as guides and attaching elements in order to achieve a 1.5 mm tolerance.
First Floor Assembly and Growth
In the case of growths a trailer-crane transport is used that allows to rapidly tow the growth module; in order to position it; first the deck roof slab of the ground floor is removed and the growth element is placed for then placing again the slab which formerly was from the ground floor on the growth module thus forming the deck roof slab of the second story.
For comprising the constructive system one of the dwellings is used, such as can be seen in
The illustrated economical dwelling is made up from a duplex type house, that is two dwellings that share a common central wall, which for illustration purposes shall be identified as right or left in terms of their orientation from the inside of the dwellings, which has a right, ground floor residential module 27, a ground floor technical module 28 and a left, ground floor residential module 29. Above the technical module 28 a ground floor technical module vault slab 30 is placed.
Above the ground floor modules a right, upper floor residential module 31, an upper floor technical module 32 and a left, upper floor residential module 33 are placed. Above the upper floor modules a right residential module wall 35, an upper floor technical module slab 34 and left, upper floor residential module slab 36 are respectively placed.
It is important to remember that the system is so versatile that a huge variety of dwellings and urban elements could be created under this same concept.
Upper Floor Modules
Ground Floor Technical Module
As can be seen in
On the rear side of the technical modules, seen from the front of the dwelling, there are bathrooms 65 in which the left 41 and right 42 bathroom-kit components are installed which can be seen in more detail in
Upper Floor Modules
As the ground floor, the upper floor is formed by an upper floor technical module 32 and two right 31 and left 33 residential modules.
Upper Floor Residential Modules
The left, upper floor residential module corresponds to a mirror image of the right module.
Upper Floor Technical Module
The upper floor technical module is a monolithic structure having a longitudinal wall 68 separating the bathrooms from the corresponding right and left modules.
Components and Slabs
Closet Component
Bathroom Kit Component
Washing Sink Component
The right 43 and left 44 ground floor technical module washing components which are generally embedded in the rear wall 56 of the ground floor technical module are clearly seen on
Patio Wall and Roof Components
Stair Component
Stair components for the left residential module 47 and for the right residential module 48, such as can be seen in
Slabs
Vault slab 30 for the lower floor technical module can be seen in
Finally,
The present invention has been clearly disclosed and illustrated according to the preferred embodiment of the invention only for clarity and understanding purposes. It is to be understood from this that no unnecessary limitations must exist. The invention is not limited to the exact details shown and disclosed, and therefore included are all the obvious variations for a person skilled in the art to which this invention belongs defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| PA/a2005/013858 | Dec 2005 | MX | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/MX2006/000136 | 11/29/2006 | WO | 00 | 12/2/2008 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2007/069877 | 6/21/2007 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3762112 | Evans et al. | Oct 1973 | A |
| 3785314 | Scanlan | Jan 1974 | A |
| 4180233 | Johnson | Dec 1979 | A |
| 4773523 | Hansen et al. | Sep 1988 | A |
| 5081805 | Jazzar | Jan 1992 | A |
| 6067771 | Blankenship | May 2000 | A |
| 6253504 | Cohen et al. | Jul 2001 | B1 |
| 20100088975 | Klersy | Apr 2010 | A1 |
| Number | Date | Country |
|---|---|---|
| 01280181 | Nov 1989 | JP |
| 04343977 | Nov 1992 | JP |
| 05071230 | Mar 1993 | JP |
| 05263529 | Oct 1993 | JP |
| 06042179 | Feb 1994 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20090145079 A1 | Jun 2009 | US |
