Patent Publication Number: US-2017348604-A1

Title: Magnetic building blocks and methods of manufacturing thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit under 35 U.S.C. §119(e) of Provisional Patent Application Ser. No. 62/344,873, filed Jun. 2, 2016, and further claims the benefit under 35 U.S.C. §119(e) of Provisional Patent Application Ser. No. 62/472,464, filed Mar. 16, 2017, the disclosures of all of which are incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention is directed to interlocking toy building blocks having magnets embedded therein and to methods for manufacturing such interlocking toy building blocks. 
     2. Description of Related Art 
     Toy blocks or bricks are typically fabricated from wood, plastic, or foam pieces, and form various shapes that are used as building blocks. Playing with the toy blocks builds strength in a child&#39;s fingers and hands, improves eye-hand coordination, and teaches children about different shapes. Playing with the toy blocks also encourages interaction creativity and imagination, and provides for social play. 
     The toy building blocks typically are fabricated from wood or plastic. Wooden toy blocks are susceptible to hosting germs and bacteria as a result of their organic composition. In contrast, polymeric blocks are easier to clean; thus, preventing the transfer of germs and bacteria, particularly if blocks are used in schools, or hospitals where there is a large communal gathering. The toy building blocks also typically are made available in a variety of colors or are marked with numbers or letters painted or imprinted thereon. Painted wooden blocks typically fade or otherwise lose their color or mark. Some paint, when consumed, can be hazardous particularly if a high Volatile Organic Compound (“VOC”) is present. Unlike wooden blocks, building blocks manufactured from polymers are not require to be painted. Plastic or polymeric building blocks can have their colors embedded in the pellets thus making it part of the composition. 
     Interlocking toy building blocks and bricks provide for the attachment or mating of toy block faces having a mechanical interlocking feature. For example, some building blocks have a top face that includes a protrusion extending outwardly therefrom that is received within a corresponding cavity extending inwardly into a bottom face of another building block. However, such mechanically interlocking building blocks require the precise positioning of the protrusions of one building block with the corresponding cavity of another building block, and human force to mate the blocks, which can be problematic for individuals of all ages who lack the strength and/or coordination to mate the blocks. 
     Some toy building blocks employ magnets to bring together the blocks to build upon an assembly of the blocks. However, the magnetic toy building blocks currently in the marketplace employ exposed magnets which are hazardous to kids if ingested. For example, wooden toy blocks typically employ wood glue to attach wooden subcomponents encasing a magnet. Wood glue can become loosened if exposed to relative elevated temperatures which can loosen the glue, thus loosening up the mating faces and revealing the magnets therein which creates a hazard for children. Moreover, fabricating wooden blocks having magnets disposed thereon is labor intensive and comparatively of high cost in relation to fabricating plastic or polymeric blocks having magnets disposed therein such as by, for example, injection molding. 
     Injection molding is a common manufacturing method for plastic toys including toy building blocks. A plastic or polymer material is injected under pressure into a two-part mold. The material is allowed to cool, the mold is opened, and the solid building blocks inside the mold are ejected from the mold. However, there are many known problems associated with injection molding. Poorly designed, poorly made, or deteriorating molds produce defects in the final product. A mold fabricated from a relatively low-cost material will wear rapidly; but higher quality molds fabricated from steel or stainless steel require a relatively high capital expenditure for fabricating toy blocks. The injection molding process often yields defective products such as, for example, an inadequate amount of plastic or polymer that does not fully fill out the mold during injection will result in an incomplete part. Other known problems resulting in defective product include not properly heating the plastic or inadequately pressurizing the mold such that the plastic does not fill out the mold. 
     Additional problems must be overcome when using an injection molding process to form toy building blocks having magnets disposed therein. The positioning of magnets in a mold is a complicated and costly process. The mold components must be fabricated to include place-holders or mounts for the magnets. Thus, separate molds must be fabricated for each alternative magnet positioning within a building block. In addition, the injection of the plastic or polymer into the mold and the subsequent application of pressure often dislodges the magnets placed within the mold such that the magnets are particularly positioned within the finished product. It is further known that injection-molded building blocks exhibit a seam which is known to deteriorate over time thus revealing the magnets therein which creates a hazard for children. 
     Additive Manufacturing, commonly known as 3-D Printing, is another common manufacturing method for plastic toys including toy building blocks. Additive manufacturing is a process in which layers of material are formed under computer control to produce a finished three-dimensional object. Objects can be of almost any shape or geometry and are produced using a digital design such as, for example, digital model data from an actual prototype or an electronic data source such as an additive manufacturing file (“AMF”) or computer-aided design (“CAD”) model. However, like injection molding, there are many known problems associated with additive manufacturing, and in particular, with additive manufacturing of toy building blocks having magnets embedded therein. Such building blocks produced by additive manufacturing are fragile and become delaminated thus revealing the magnets therein which creates a hazard for children. Moreover, the complexity of the additive manufacturing process itself is often daunting and involves substantial adjusting of processing formats, parameters, and mechanical features Like injection molding, the additive manufacturing process itself often displaces the magnets to be particularly positioned within the finished product. 
     What is needed is a toy interlocking building block that is relatively inexpensive to manufacture, thus making the final product relatively inexpensive at retail, and does not employ coatings of paint and glue. What is further needed is a toy interlocking building block that requires minimal effort to align and mate with another block. What is also needed is a manufacturing process for fabricating the interlocking toy building blocks that employs magnets to bring together the blocks to build upon an assembly of the blocks; wherein such a manufacturing process encapsulates or otherwise traps the magnets into a fixed position thereby preventing the exposure or loss of a magnet and creating a hazard for children. What is also needed is a manufacturing process for toy building blocks that produces seamless building blocks having the magnets properly positioned therein. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention is directed to an interlocking toy building block, the block comprising: a first block body; and at least one first magnet positioned inwardly into the first block body a first predetermined distance from a first outer surface of the first block body to provide a first predetermined magnetic polarity, positive or negative, to the first outer surface; wherein, when the first outer surface is brought into close proximity with a second outer surface of a second block body having at least one second magnet positioned a second predetermined distance therein and exhibiting a second predetermined magnetic polarity opposing the first predetermined magnetic polarity, the first outer surface configured to mate with the second outer surface in an interlocking position. 
     In one embodiment of the present invention, the first and second predetermined distances are in the range of from about 1 mm to about 5 mm. In one embodiment of the present invention, the first and second predetermined distances predetermined distances are equal. In one embodiment of the present invention, the first and second predetermined distances predetermined distances are in the range of about 2 mm. 
     In one embodiment of the present invention, the block further comprises at least a first pair of magnets defined by the at least one first magnet and the at least one second magnet; and a potential magnetic force F m  between the at least one first magnet and the at least one second magnet determined by the formulation: F m =F o  e −rd  where F o  is the initial force (i.e., no separation distance between magnets), and e −rd  is the exponential function of the rate of magnetic field decay “r” of a substrate of the magnets and the distance “d” between the magnets. 
     In one embodiment of the present invention, the first block body is fabricated from a material having a density in the range of about 1×10 −6  kg/mm 3  to about 1.25×10 −6  kg/mm 3 . In one embodiment of the present invention, the first block body is fabricated from a material having a density in the range of about 1×10 −6  kg/mm 3  to about 1.25×10 −6  kg/mm 3 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a magnetic building block in accordance with one embodiment of the present invention. 
         FIG. 2  is side elevation view of the magnetic building block of  FIG. 1 . 
         FIG. 3  is a front elevation view of the magnetic building block of  FIG. 1 . 
         FIG. 4  is an isometric view of a plurality of the magnetic building blocks of  FIG. 1  showing the magnetic properties thereof. 
         FIG. 5  is side elevation view of another configuration of a magnetic building block in accordance with one embodiment of the present invention. 
         FIG. 6  is side elevation view of another configuration of magnetic building block in accordance with one embodiment of the present invention. 
         FIG. 7  is an isometric view of another configuration of a magnetic building block in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention provides interlocking toy building blocks having magnets embedded therein and methods for manufacturing such interlocking toy building blocks. The toy interlocking building blocks of the present invention are relatively inexpensive to manufacture such that the final product is correspondingly relatively inexpensive at retail. The toy interlocking building blocks of the present invention do not employ coatings of paint and glue, and require minimal effort to align and mate with another block. The present invention further provides methods of manufacturing for fabricating the interlocking toy building blocks that encapsulate or otherwise trap the magnets into a fixed position thereby preventing the exposure or loss of a magnet and creating a hazard for children. The methods of manufacturing of the present invention produce seamless building blocks having the magnets properly positioned therein. 
     One embodiment of a method of manufacturing of the present invention employs embedded magnets within a whole injection molded building block wherein the injection molded process traps the magnets in a predetermined position as the molten plastic fills the mold and encapsulates the magnets disposed therein. Another embodiment of a method of manufacturing of the present invention employs a whole additive manufacturing wherein the additive manufacturing process traps and encases the embedded magnets in a predetermined position within the molten plastic inside a sealed surface. In both such processes, the blocks are manufactured from polymers that are not required to be painted because various colors embedded in the raw plastic material, such as for example, plastic pellets or powder, thus making color a feature of the composition of the building block. In addition, both such processes can advantageously use raw plastic material manufactured from recyclable materials or organic polymers, known as bioplastics, produced from renewable sources such as barley, wheat, and other renewable materials. 
     One embodiment of the interlocking toy building blocks of the present invention includes magnets embedded therein wherein magnetism provides the physical property for interlocking the building blocks. The present invention employs the physical properties of magnetism to create locking features, as in the case of two magnets attracting each other, or the case of a magnet being attracted to a metallic surface such as iron, cobalt, nickel or an alloy derivation of such metallic elements. This feature enables people of all ages who do not possess the strength and/or coordination to mate mechanical interlocking building blocks to use the interlocking toy building blocks of the present invention. In addition, users learn of, and are encouraged to explore, related aspects of science such as magnetism, magnetic fields, permeability, porosity, and the like. The magnetic whole polymeric building blocks of the present invention are easy to clean and do not employ coatings of potentially hazardous paint. 
     An interlocking toy building block  100  of the present invention is shown in  FIGS. 1, 2 and 3 , and is referred to hereinafter as “block  100 .” The block  100  includes a block body  110  having an outer surface  112  on each side of the block body  110 . One or more magnets  120  are positioned within the block body  110  below each outer surface  112  such that the magnets  120  lie embedded inside the block  100 . Each magnet  120  is positioned a predetermined distance X 1  inwardly into block body  110  from a respective outer surface  112  to ensure magnetism radiates and provides for interlocking one block  100  with other blocks  100 . The outer surface  112  of the block body  110  includes a top surface  113 , a front surface  114 , a bottom surface  115 , a back surface  116 , a left-side surface  117  and a right-side surface  118 . 
     A plurality of the magnetic building blocks of the present invention are shown in  FIG. 4  with an indication of the magnetic properties thereof, namely, blocks  100 A,  100 B,  100 C,  100 D and  100 E. Magnetic poles of opposite polarity attract each other, and such polarity is indicated as positive “+” and negative “−”. As negative charged surface areas of a geometrical shape, meet positively charged surface areas of other geometrical shapes, a magnetic attraction between the mating faces occurs and causes the geometrical shape to lock into a position abutting each other. Each of the blocks  100  respectively includes magnets  120  that are strategically positioned within the block body  110  to provide a predetermined type of polarity, positive or negative, thereby providing positively and negatively charged mating outer surfaces  112 . When different blocks  100  having magnets  120  embedded therein such that opposing positively and negatively charged mating outer surfaces  112  of respective blocks  100  are brought into close proximity, the opposite magnetic charge leads to a magnetic attraction between the blocks  100  which mates the outer surfaces  112  into an interlocking position. 
     For example, block  100 A includes magnets  120 A embedded within a top surface  113 A and a bottom surface  115 A wherein the respective embedded magnets  120 A define a negative polarity facing outwardly. Block  100 B includes magnets  120 B embedded within a top surface  113 B and a bottom surface  115 B wherein the respective embedded magnets  120 B define a positive polarity facing outwardly. Thus, the top surface  113 A of block  100 A is magnetically attracted to the bottom surface  115 B of block  100 B and the blocks  100 A and  100 B are magnetically interlocked. Similarly, block  100 C includes magnets  120 C embedded within a top surface  113 C wherein the embedded magnets  120 C define a positive polarity facing outwardly. Thus, the top surface  113 C of block  100 C is magnetically attracted to the bottom surface  115 A of block  100 A and the blocks  100 A and  100 C are magnetically interlocked. In contrast to blocks  100 A and  100 B, the magnets  120 C embedded within a bottom surface  115 C of block  100 C define a reverse polarity facing outwardly relative to the top surface  113 C, namely, the embedded magnets  120 C define a negative polarity facing outwardly from bottom surface  115 C. Thus, various blocks  100  are employed to build upon each other in a variety of mating positions. 
     The magnets  120  embedded within the left-side surface  117  and the right-side surface  118  of each block  100  similarly define predetermined polarities facing outwardly. For example, block  100 A includes magnets  120 A embedded within a left-side surface  117 A wherein the respective embedded magnets  120 A define a negative polarity facing outwardly. Block  100 D includes magnets  120 D embedded in a right-side surface  118 D wherein the respective embedded magnets  120 D define a positive polarity facing outwardly. Thus, the left-side surface  117 A of block  100 A is magnetically attracted to the right-side surface  118 D of block  100 D and the blocks  100 A and  100 D are magnetically interlocked. Similarly, block  100 A includes magnets  120 A embedded within a right-side surface  118 A wherein the respective embedded magnets  120 A define a positive polarity facing outwardly. Block  100 E includes magnets  120 E embedded in a left-side surface  117 E wherein the respective embedded magnets  120 E define a negative polarity facing outwardly. Thus, the right-side surface  118 A of block  100 A is magnetically attracted to the left-side surface  117 E of block  100 E and the blocks  100 A and  100 E are magnetically interlocked. 
     The capacity for one block  100  to mate or interlock with another block  100  is initially determined by the potential magnetic force F between the magnets  120 . The potential magnetic force F m  is effected by a predetermined distance between the magnets  120 , the material in which the magnets  120  are embedded, that is, the material from which the blocks  100  are fabricated, and the particular magnet substrate (e.g., neodymium iron boron (NdFeB), samarium cobalt (SmCo), alnico, and ceramic or ferrite magnets). The potential magnetic force F m  between the magnets  120  is determined by the formulation: 
     
       
      
       F 
       m 
       =F 
       o  
       e 
       −rd  
      
     
     where F o  is the initial force (i.e., no separation distance between magnets), and e −rd  is the exponential function of the rate of magnetic field decay “r” of the magnet substrate and the distance “d” between the magnets. 
     In one embodiment of the present invention, the magnets  120  are embedded a predetermined distance X 1  inwardly into block body  110  from a respective outer surface  112  in the range of from about 1 mm to about 5 mm. In one embodiment, the predetermined distance X 1  is about 2 mm. In one embodiment, the initial force F o  of two magnets  120  is about 1.36 kg (3 lbs) at a distance d of 0. Thus, it can be estimated that at the predetermined distance X 1  of about 2 mm, the potential magnetic force F m  between two the magnets  120  is about 0.32 kg (0.7 lbs). 
     In differing embodiments, two to five magnets  120  are embedded along one outer surface  112  of the block body  110 . For example, the top surface  117 A of block body  110 A and the bottom surface  115 B of the block body  110 B are mated or interlocked by four pairs of magnets  120 . Thus, the corresponding potential magnetic force F m  between the four pairs of magnets  120  is about 2.8 lbs (4 pairs×0.7 lbs per pair). Accordingly, the potential force of attraction of one outer surface  112  of one block  100  to another outer surface  112  of another block  100  is defined by the relation of the distance between a pair of interacting magnets  120  and the number of pairs of magnets interacting with each other. Thus, the total potential force of attraction F t  of one outer surface  112  of one block  100  to another outer surface  112  of another block  100  is determined by the formulation: 
         F   t =Σ Number of pairs of magnets× F   o    e   −rd  
 
     The total potential force of attraction F t  is further effected by the density p of the material in which the magnets  120  are embedded, the material from which the blocks  100  are fabricated. For polymers and other amorphous materials, the higher the density of the material, the greater the resistance to the magnetic force carried therethrough. Accordingly, the total actual force of attraction F a  of one outer surface  112  of one block  100  to another outer surface  112  of another block  100  is diminished in an inverse relationship to the density ρ of the material from which the blocks  100  are fabricated. Thus, the total actual force of attraction F a  of one outer surface  112  of one block  100  to another outer surface  112  of another block  100  is determined by the formulation: 
         F   a =Σ Number of pairs of magnets× F   o    e   −rd  ×(1 /p )
 
     where ρ is the density of the material from which the blocks  100  are fabricated. Such density may be calculated as the mass of the block  100  divided by the volume of the block  100 . 
     In one embodiment, to the density p of the material from which the blocks  100  are fabricated is in the range of about 1×10 −6  kg/mm 3  to about 1.25×10 −6  kg/mm 3 . 
     In one embodiment, the predetermined distance X 1  is about 2 mm and the density ρ of the material from which the blocks  100  are fabricated is about 1.2×10 −6  kg/mm 3 . 
     The methods of manufacture of the present invention include a whole injection molded process and a whole additive manufacturing process wherein each process traps and encases the embedded magnets in a predetermined position within the molten plastic inside a sealed surface. Both processes enable the formation of a variety of three-dimensional geometric shapes of building blocks having magnets embedded therein, such as for example, cube, cuboid, spherical, cylinder, torus, triangular pyramid, square pyramid, truncated pyramid, triangular prism, and the like, and other more complex geometric shapes such as a dodecahedron. 
     The whole injection molded process of the present invention includes fabricating an injection mold which defines the shape of the building block  100 . A fixture for suspending the magnets  120  within the mold in a predetermined configuration is fabricated and fixedly positioned within the mold, or integrally formed within the mold. Molten plastic is injected into the mold under sufficient pressure and subsequently cooled wherein the finished building block  100  is obtained. Lastly, the polarity of the outer surfaces  112  of respective blocks  100  are verified. 
     The whole additive manufacturing process of the present invention includes preparing a computer-aided design model for use as the blueprint for the additive manufacturing machine which defines the shape of the building block  100 . The magnets  120  are positioned within the block body  110  during the additive manufacturing process, either manually or through automation (i.e., robots). A fixture may be employed for postioning the magnets  120  during the additive manufacturing process of the block body  110 . The position of the magnets  120  during the additive manufacturing process is fixed or secured within the block body  110  by the molten plastic itself or by employing an adhesive such as glue. Lastly, the polarity of the outer surfaces  112  of respective blocks  100  are verified. 
     In one embodiment, the building block  100  is manufactured from a polymer using the whole injection molded process or the additive manufacturing process. Subsequently, one or more cavities of a predetermined configuration are hollowed out into which one or more magnets are disposed. The cavity is then resealed and polished. In one embodiment, the building block  100  is formed as a hollow block into which one or more magnets are disposed and sealed therein. In one embodiment, the magnets  120  are coated with a thermoset polymer, then heated and formed to a desired shape. In one embodiment, the building block  100  is manufactured via dual additive manufactured molding with automated insertion of the magnets  120 . 
     As shown in  FIG. 5 , in one embodiment, a block  200  includes a block body  210  having a plurality of magnets  220  embedded therein and positioned flush with an outer surface  212  thereof. The magnetic whole polymeric building Block Mold could be manufactured to have magnets sit on the surface of the blocks. As shown in  FIG. 6 , in one embodiment, a block  300  includes a block body  310  having a plurality of magnets  320  embedded therein and positioned extending outwardly from an outer surface  312  thereof. 
     As shown in  FIG. 7 , in one embodiment, a block  400  includes a block body  410  having one or metal components  422  embedded therein. Accordingly, blocks  100  having magnets  120  embedded therein are attracted to and will mate with blocks  400  because the metal components  422  are fabricated from, for example, iron (Fe) cobalt (Co), nickel (Ni), and to their respective based alloys. 
     In a finished condition, multiple building blocks  100  can be positioned to form selectively desired objects, such as for example, toy houses, toy cars, toy dinosaurs, toy trucks, toy dogs, and the like, based upon actual or imagined objects. The magnetic attraction of the respective outer surfaces  112  of the building blocks  100  would mate and interlock the different blocks  100  into a select position or configuration to form the desired object. 
     The building blocks  100  having the magnets  120  embedded therein can be used for other than play or entertainment purposes. Given the iron base of nails, a block  100  can be used to find studs in a wall by identifying the location of nails via magnetism. Because of the magnetic properties of the block  100 , it can be used to fix items to appliances, such as a child&#39;s art to a refrigerator. Moreover, the blocks  100  can be employed to teach the principles of magnetics and magnetism to children. The blocks  100  can be used by an architect to build a model of a commercial or residential structure prior to building it wherein the model would serve as an opportunity to study a building design in a real-world application. 
     The blocks  100  of the present invention provide entertainment that enhances motor skills, creativity, critical thinking, spatial awareness and synergism. The blocks  100  further provide for ease of play for some persons who may have difficulty using building blocks with mechanical locking features. The blocks  100  also provide an opportunity to teach users about magnetism and magnetic properties of materials as well as bringing ideas from a two-dimensional configuration to a three-dimensional configuration. 
     The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. In addition, the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. 
     Although the invention has been described with reference to particular embodiments thereof, it will be understood by one of ordinary skill in the art, upon a reading and understanding of the foregoing disclosure that numerous variations and alterations to the disclosed embodiments fall within the spirit and scope of this invention and of the appended claims. For example, those of ordinary skill in the art should recognize that one or more of the angles and dimensions of various structural features of the invention may be altered without deviating from the scope of the present invention.