Abstract:
A set of large, hollow, lightweight, seamless, rigid wooden blocks provides a variety of shapes such as cubes, flat or elongated right-parallelepiped pieces, as well as pyramids, and round cylindrical blocks. The pieces are large compared to the size of a child, but being hollow they are not overly heavy. There are no openings in the pieces, so gripping the smooth surfaces to throw them is not a simple task for a small child; thus they are safer since they are more amenable to use on a plane surface and being gripped with both hands. Also, the construction of plywood provides an optimum degree of heft as opposed to large plastic or foam pieces. The size makes the blocks useful either for either single use or group play. The blocks are durable and sanitary.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to large hollow wooden building block toys. 
       BACKGROUND OF THE INVENTION 
       [0002]    Building block sets for small children or toddlers should be appropriate for use in a variety of child care settings whether home based or institutional. They must be durable and safe, while also promoting the natural experimentation and curiosity of children. Finally, they should be affordable. 
         [0003]    The prior art reveals familiar small cubic solid wood building blocks that are traditional, as well as larger building blocks and toy systems. Niebel in U.S. Pat. No. 1,379,648 describes a toy furniture set with solid elements (some with recesses) that nest into each other to form a large rectangular block. A construction set of Roh et al. (U.S. Pat. No. 5,330,379) reveals a toy that can be stored as a sofa, but which is transformable into a playhouse with walls and gables. Odier of U.S. Pat. No. 3,608,906 describes multisided puzzle pieces in the form of frame supports of cubic or tetrahedral shapes which accept changeable planar side panels forming hollow blocks which are the basis of puzzles. Felgenhauer et al. In U.S. Pat. No. 5,827,105 describes a unit toy system with interlocking landscape shaped molded hollow blocks which can be used to construct a variety of artificial three dimensional landscapes. Bluthhardt in U.S. Pat. No. 2,147,237 describes a toy building block set including block shapes with u-shaped cutouts to facilitate building interlocking structures. Secter in U.S. Pat. No. 3,773,329 describes a set of six similar solid right-parallelepiped blocks with hidden connections permitting relative pivoting; they form solid-geometrical puzzles and furniture arrangements. Chang in U.S. Pat. No. 6,568,981 describes a large soft brick construction set with various shapes; the lightweight foam blocks are covered with display material which attaches to double-sided hook material strips to permit temporary attachment of the pieces to each other. Chambers in U.S. Pat. No. 1,471,943 describes conventionally sized hollow or solid pyramidal shaped blocks. 
         [0004]    Additionally, a set of open sleeved rectangular blocks made from four attached wooden planks are sold by guidecraft.com. 
         [0005]    Although the prior art does reveal large sized blocks, some light weight, some of wood, and some hollow, prior art does not reveal a building block set of large hollow wooden building blocks of various shapes, where each of the blocks are sturdy, smooth and large enough to only be carried by two hands of a child. 
       OBJECTS OF THE INVENTION 
       [0006]    It is an object of the present invention to provide safe, sanitary, durable, large building block toys which are lightweight and easy to handle. 
         [0007]    Other objects which become apparent from the following description of the present invention. 
       SUMMARY OF THE INVENTION 
       [0008]    Safety is paramount in toys for small children. Obviously, no choke hazards should be provided. Plastic toys can be toxic. Mold release compounds used in their manufacture have been implicated in hormonal changes as well as liver problems. A good alternative to plastic is wood finished in a smooth surface of even consistency and coated with non-toxic wax or varnish. Wood is also very durable and depicts craftsmanship which has superior perceived as well as real value. 
         [0009]    A set of large, light weight closed hollow wooden blocks is provided. Each block is a hollow block made of smooth, non-porous wood panels. Each rigid, non-depressible block is closed on all sides, and has a single hollow void inside. Each of the blocks is constructed of sufficient size that two hands of a child, for whom the block is made, are required to hold or carry the block. 
         [0010]    Each block is configured to have a geometric shape which is dimensioned of a pre-determined minimum size in height, width and depth, so that the block is carried by two hands of a child. For example, a block having at least one edge of a minimum size of 12 cm has a surface area which exceeds the palm of a hand of a child. This requires the child to carry the block so dimensioned with a minimum surface edge with both hands. This reduces the ability of the block to being thrown as a projectile by a single hand of a child, thereby rendering the set of blocks safe and aesthetically interesting at the same time. 
         [0011]    The walls of each block are sufficiently thin to make the block light enough for the child to easily lift and carry the block. 
         [0012]    Unlike lightweight, foam blocks, such as described in Chang &#39;981, the smooth surfaces of the blocks of even consistency are rigid and not indented with any recesses or surface irregularities to grab into, other than the typical arch of an arched block, which arch has a depth deterring manual grasping by one hand. 
         [0013]    Unlike the three dimensional tetrahedral puzzles assembled by magnetic panels, or ferromagnetically painted wood or plastic panels, of Odier &#39;906, the smooth wooden hollow blocks of the present invention are strictly smooth wooden panels to the touch by children&#39;s hands. 
         [0014]    Unlike the set of open sleeved rectangular blocks made from four attached wooden planks, which are sold by guidecraft.com, the smooth, closed hollow wooden blocks of the present invention are not indented with any recesses or surface indentations to grab into, other than the typical arch of an arched block, which arch has a depth deterring manual grasping by one hand. 
         [0015]    The block set of this invention provides a variety of shapes such as cubes, flat or elongated right-parallelepiped pieces, as well as pyramids, hemispheres and round cylindrical blocks. The pieces are large compared to the size of a child, but being hollow they are not overly heavy. There are no openings in the pieces, other than a wide deep arch in an arched block, so gripping the smooth surfaces to throw them is not a simple task for a small child; thus they are safer since they are more amenable to use on a plane surface and being gripped with both hands. Also, the construction of plywood provides an optimum degree of heft as opposed to large plastic or foam pieces. The size makes them ideal either for either single use or group play. The durability and ease of cleaning is a great asset for use in day care centers. 
         [0016]    The pieces using flat surfaces have seams bonded using non-toxic wood glue which are assembled with the use of wire brads. The pieces with curved surfaces incorporate plywood ends or sections and wood veneer over the curved portions which matches the finish of the plywood. 
         [0017]    Mats with block base outlines are also provided. They may be used on a horizontal surface as a guide to build layouts such as a “small village”. Other mats can be used vertically to illustrate placement of blocks to form “brick walls” or other projects 
         [0018]    The present invention also includes a method of stimulating a child&#39;s imagination and creativity includes the steps of 
         [0019]    a) providing a set of large-sized, smooth, hollow child play blocks, each of the blocks having an outer surface, wherein each outer surface is substantially seamless and substantially rigid, wherein the set of blocks include individual respective blocks of varying shapes. 
         [0020]    b) allowing one or more child users to create varying structures using the set of blocks; 
         [0021]    c) allowing one or more of the child users to use each structure for imaginative play; and, 
         [0022]    d) allowing one or more of the child users to modify said varying structures at will. 
         [0023]    The aforementioned method can also be used to teach children fundamental structural soundness and strength of materials by each child respectively manipulating the set of large, hollow, smooth blocks. 
         [0024]    The aforementioned method can also be used to teach fundamental appropriate social interaction among children, by allowing said at least two child users to use said structure for imaginative play while interacting socially with each other; and allowing the child users to modify the varying structures at will. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which: 
           [0026]      FIG. 1  is a perspective view of the block set of this invention with child present to indicate scale. 
           [0027]      FIG. 2  is a perspective view of a rectangular block of this set. 
           [0028]      FIG. 3  is a perspective detail of a corner of the block of  FIG. 2 . 
           [0029]      FIG. 4  is a perspective exploded view of a hollow cubic block of this set illustrating its assembly of plywood sides using wire brads. 
           [0030]      FIG. 5  is a perspective detail of the construction of a corner of the cubic block of  FIG. 4 . 
           [0031]      FIG. 5A  is a close-up detail view in crossection, as taken and viewed along line “ 5 A- 5 A” of  FIG. 5 , showing a detail of a corner of the cubic block of  FIG. 4 , depicting a thin veneer layer covering a fastener. 
           [0032]      FIG. 6  is a perspective view of a ramp block from the block set. 
           [0033]      FIG. 7  is a perspective view a different ramp block. 
           [0034]      FIG. 8  is a perspective view of a long block with square crossection. 
           [0035]      FIG. 9  is a perspective view of a flat rectangular block. 
           [0036]      FIG. 10  is a perspective view of a narrow block with triangular sides. 
           [0037]      FIG. 11  is a perspective view of a block as in  FIG. 10  with the apex truncated. 
           [0038]      FIG. 12  is a perspective view of a child holding and lifting a large block with both hands. 
           [0039]      FIG. 13  is a perspective view of two children interacting with the block set of this invention. 
           [0040]      FIG. 14  is a perspective view showing an optional mat on a horizontal surface showing base outlines for a variety of blocks. 
           [0041]      FIG. 15  is a perspective view showing an optional vertical mat with block wall outlines. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]      FIG. 1  shows block set  1  of this invention besides a child  2  of age for which the set is designed. Note that there are a variety of shapes including rectangular, pyramid, long blocks, flat blocks, arched block, and round cylindrical blocks. As a size comparison, note that dimension “L” of the longest block is nominally 48 cm. 
         [0043]      FIG. 2  shows a close up of a rectangular block  10  of hollow plywood construction as is typical of all blocks of this set. The detail of  FIG. 3  shows a corner of three mutually orthogonal sides,  11 ,  12  and  13 , of block  10 . A cubic block  15  is shown in an exploded view in  FIG. 4 . Its edge dimension is nominally 12 cm. Each panel  16  is nominally 6 mm (¼″) thick and it is assembled using wire brads  17  after each seam is spread with non-toxic wood glue for very strong bonding. Corner construction detail is shown in  FIG. 5 . 
         [0044]    Flat and curved surfaces  3  in  FIG. 1  on the triangular, rectangular, cubic and round cylindrical blocks and on the arch surface of the arch block are covered in real wood veneer layer  18 , such as, for example, a very thin layer approximately ½ millimeter in thickness, of a wood, such as birch wood, which is bonded to plywood end caps or arch support and finished to match the plywood surfaces. For example, the cylinders shown in  FIG. 1  can be made by attaching flexible panels around an array of upright supports extending between flat round top and bottom discs. Arches may be formed by adding veneer arches over arched panels. Hollowed out, sanded and finished hemispherical half domed blocks  38  shown in  FIG. 14  may also be provided. 
         [0045]    Alternatively, the set of hollow blocks may be provided with a small, auxiliary, solid half domed shaped block. 
         [0046]    Note that the construction selected results in blocks that are much lighter than solid wooden blocks of the same dimensions, however they are substantially heavier than similarly sized hollow plastic blocks. This results in the desired play ergonomics whereby blocks are easy to lift with both hands, are sufficiently resistant to knock-down, and are not prone to become airborne.  FIGS. 6-11  show perspective views of a selection of different block shapes from the set of this invention. 
         [0047]      FIG. 12  shows a child  2  carrying a large flat block  23  with both hands. A solid wooden or plastic block would have been too heavy, while a foam or hollow plastic block would have typically been grasped with only one hand. Block  23  requires development of eye and two-handed coordination to carry it successfully.  FIG. 13  shows two children  2  interacting with a common building project using the set  1  of this invention. 
         [0048]    An optional patterned template floor mat  30  with base outlines corresponding to the various blocks is shown in  FIG. 14 . Outline  31  corresponds to block  23  while outlines  33  and  35  correspond to blocks  32  and  34  respectively. It can be used to offer direction in building a variety of multi-block projects. An optional patterned template vertical wall mat  39  with block outlines  40  is shown in  FIG. 15  illustrating the formation of a wall out of blocks  23 . Mats with a variety of outlines for a wide variety of play may be optionally provided. 
         [0049]    The blocks are designed to be large enough so that a child must use both hands to hold the block, which reduces the possibility of the block being a thrown projectile. It also gives the child a more tangible size to make more life-like sized constructions, such as the arched tower of  FIG. 13 , including an arch through which a ball can be rolled, and an open window formed by four blocks, so that the children can see each other through the assembly of blocks. Additionally, the large blocks can be assembled in structures such as shown in  FIG. 1 , to provide structural environments, such as walled areas or bridges upon which to manipulate other toys, such as toy vehicles. 
         [0050]    Therefore, the blocks have a minimum range of sizes to achieve these objectives. For example, the block set may have respective large, hollow wooden blocks of varying shapes which include at least one rectangular-shaped block, at least one wedge-shaped block having a triangular crossection, at least one pyramidal-shaped block, at least one block having a flat half-round arch shape, at least one block having a trapezoidal shape, at least one block having a cubic shape and at least one cylindrically-shaped block. 
         [0051]    For example,  FIG. 6  shows a wedge shaped block of triangular crossection having preferable minimal dimensions of 48 cm in length, 12 cm in height and 12 cm in depth.  FIG. 7  shows another wedge shaped block of triangular crossection having preferable minimal dimensions of 12 cm in length, 12 cm in height and 12 cm in depth.  FIG. 9  shows a rectangular block with a minimum length of 48 cm. However, these examples shown in  FIGS. 6 ,  7  and  9  are merely exemplary, and the dimensions may be provided a range of dimensions, so long as the dimensions provide a block with at least one surface area having an edge dimension exceeding the size of a palm of a child&#39;s hand. 
       EXAMPLE OF MINIMUM RANGES OF SIZES OF SET OF BLOCKS 
       [0052]    The following ranges of sizes are applicable to provide a set of blocks, wherein each block has at least one surface area having an edge dimension exceeding the size of a palm of a child&#39;s hand: 
         [0053]    The block set may optionally have one or more wedge-shaped blocks having a triangular crossection, including a set of at least three wedges of differing respective angularity, wherein a first one of the at least three wedge shaped blocks comprises a cross sectional length of about from about 36 cm to about 60 cm, a crossectional height of from about 9 cm to about 18 cm, and a width of from about 9 cm to about 18 cm; and wherein further a second one of the at least three wedge shaped blocks comprises a cross sectional length of from about 9 cm to about 18 cm, a crossectional height of from about 9 cm to about 18 cm, and a width of from about 9 cm to about 18 cm; and wherein further a third one of the at least three wedge shaped blocks comprises a cross sectional length of from about 18 cm to about 30 cm, a crossectional height of from about 9 cm to about 18 cm, and a width of from about 9 cm to about 18 cm. 
         [0054]    The block set may optionally have one or more rectangular-shaped blocks including a set of at least five rectangular blocks of differing respective sizes, wherein a first one of the at least five rectangular blocks comprises a block of from about 36 cm long to about 60 cm long, from about 4 cm thick to about 9 cm thick and from about 9 cm wide to about 18 cm wide; and wherein a second one of the at least five rectangular blocks comprises a block of from about 18 cm long to about 30 cm long, from about 4 cm thick to about 9 cm thick, and from about 9 cm wide to about 18 cm wide; wherein a third one of the at least five rectangular blocks comprises a block of from about 9 cm long to about 18 cm long, from about 4 cm thick to about 9 cm thick, and from about 9 cm wide to about 18 cm wide; wherein a fourth one of said at least five rectangular blocks comprises a block of from about 9 cm long to about 18 cm long, from about 4 cm thick to about 9 cm thick, and from about 4 cm wide to about 9 cm wide; and wherein a fifth one of said at least five rectangular blocks comprises a block of from about 9 cm long to about 18 cm long, from about 9 cm thick to about 18 cm thick and from about 9 cm wide to about 18 cm wide. 
         [0055]    The block set may optionally have one or more cylindrically-shaped blocks including a set of at least four cylinders of differing respective dimensions, wherein a first one of the at least four cylindrical blocks comprises a cylinder of from about 9 cm long to about 18 cm long and from about 9 cm in diameter to about 18 cm in diameter; wherein a second one of the at least four cylindrical blocks comprises a cylinder of from about 18 cm long to about 30 cm long and from about 9 cm in diameter to about 18 cm in diameter; wherein a third one of the at least four cylindrical blocks comprises a cylinder of from about 18 cm long to about 36 cm long and from about 18 cm in diameter to about 36 cm in diameter; and wherein a fourth one of the at least four cylindrical blocks comprises a cylinder of from about 36 cm long to about 60 cm long and from about 18 cm in diameter to about 30 cm in diameter. 
         [0056]    The block set may optionally have one or more pyramidal-shaped blocks including a set of at least two pyramidal blocks of differing respective dimensions, wherein a first one of the at least two pyramidal blocks comprises a pyramid having a base having a length of from about 18 cm to about 30 cm, a base width of from about 9 cm to about 18 cm and a pyramidal height of from about 18 cm to about 30 cm; and wherein a second one of the at least two pyramidal blocks comprises a pyramid having a base having a length of from about 9 cm to about 18 cm, a base width of from about 9 cm to about 18 cm, and a pyramidal height of from about 18 cm to about 30 cm. 
         [0057]    The block set may optionally have one or more blocks having a flat half-round arch shape, arch having a height of from about 18 cm to about 36 cm, a length of from about 36 cm to about 60 cm, a depth of from about 9 cm to about 18 cm and an arch having a radius of from about 9 to about 18 cm. 
         [0058]    The block set may optionally have one or more trapezoidal blocks each having a height of from about 18 to about 36 cm, a top width of from about 18 to about 36 cm, a bottom width of from about 36 to about 60 cm and a depth of from about 9 to about 18 cm. 
         [0059]    The block set may optionally have one or more cubic blocks each having edges of even length, height and depth of from about 9 cm to about 18 cm. 
       PREFERRED EXAMPLE OF A SET OF BLOCKS 
       [0060]    The aforementioned ranges of sizes are illustrative and exemplary. The following is a preferred example of a set of blocks having specified dimensions with at least one surface area having an edge length exceeding the size of a palm of the hand of a child. 
         [0061]    While the aforementioned ranges indicate ranges of sizes, in a preferred set of blocks, there are one or more wedge-shaped blocks having a triangular crossection including a set of at least three wedges of differing respective angularity, wherein a first one of the at least three wedge shaped blocks comprises a cross sectional length of about 48 cm, a crossectional height of about 12 cm, and a width of about 12 cm; and wherein further a second one of the at least three wedge shaped blocks comprises a cross sectional length of about 12 cm, a crossectional height of about 12 cm, and a width of about 12 cm; and wherein further a third one of said of at least three wedge shaped blocks comprises a cross sectional length of about 24 cm, a crossectional height of about 12 cm, and a width of about 12 cm. 
         [0062]    In the preferred The block set, at least one rectangular-shaped block comprises a set of at least five rectangular blocks of differing respective sizes, wherein a first one of the at least five rectangular blocks comprises a block of about 48 cm long, about 6 cm thick and about 12 cm wide; and wherein a second one of the at least five rectangular blocks comprises a block of about 24 cm long, about 6 cm thick and about 12 cm wide; wherein a third one of the at least five rectangular blocks comprises a block of about 12 cm long, about 6 cm thick and about 12 cm wide; wherein a fourth one of the at least five rectangular blocks comprises a block of about 12 cm long, about 6 cm thick and about 6 cm wide; and wherein a fifth one of the at least five rectangular blocks comprises a block of about 12 cm long, about 12 cm thick and about 12 cm wide. 
         [0063]    Also in the preferred block set the at least one cylindrically-shaped block comprises a set of at least four cylinders of differing respective dimensions, wherein a first one of the at least four cylindrical blocks comprises a cylinder of about 12 cm long and about 12 cm in diameter; wherein a second one of the at least four cylindrical blocks comprises a cylinder of about 24 cm long and about 12 cm in diameter; wherein a third one of the at least four cylindrical blocks comprises a cylinder of about 24 cm long and about 24 cm in diameter; and wherein a fourth one of the at least four cylindrical blocks comprises a cylinder of about 48 cm long and about 24 cm in diameter 
         [0064]    In the preferred block set at least one pyramidal-shaped block comprises a set of at least two pyramidal blocks of differing respective dimensions, wherein a first one of the at least two pyramidal blocks comprises a pyramid having a base having a length of about 24 cm, a base width of about 12 cm and a pyramidal height of about 24 cm; and wherein a second one of the at least two pyramidal blocks comprises a pyramid having a base having a length of about 12 cm, a base width of about 12 cm and a pyramidal height of about 24 cm. 
         [0065]    In the preferred set each block having a flat half-round arch shape, has a height of about 24 cm, a length of about 48 cm a depth of about 10.2 cm and an arch having a radius of about 12 cm. 
         [0066]    Moreover in the preferred block set each trapezoidal block has a height of about 24 cm, a top width of about 24 cm, a bottom width of about 48 cm and a depth of about 12 cm. 
         [0067]    Additionally, the preferred block set has cubic blocks each having edges of even length, height and depth of about 12 cm. 
         [0068]    In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention. 
         [0069]    It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.