Patent Publication Number: US-6665994-B1

Title: Self-aligning building blocks

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of building blocks, usually formed of cementitious material, which are used as stacked components in the construction of walls and structures. More particularly, the invention relates to such articles which are shaped such that the blocks interlock or align when stacked. 
     Cementitious building blocks, often known as cement or concrete blocks, are well known in the masonry and construction fields. In the most common configuration, the blocks are rectangular with dimensions of approximately 8 inches in height and depth and 16 inches in length. The blocks are not solid but are provided with two vertically oriented openings separated by a lateral internal wall or web member, such that the blocks possess a shape similar to the number “8” with rectangular corners when viewed from the top or bottom. The open interiors reduce the weight of the block, allow less material to be consumed in their formation, and provide vertical channels in the finished wall structure for the passage of wiring, plumbing or conduits, or for receipt of filler materials such as poured concrete to increase strength, insulation or other properties. Such blocks have been in use for many years, and when properly joined by mortar interspersed between adjacent blocks they form extremely solid structures. Constructing a wall from discrete blocks requires a certain degree of skill, since wet mortar must be applied to the proper surfaces of the previously laid blocks and/or to the proper surfaces of the block to be laid, then the block must be positioned and aligned with the previously laid blocks such that the height of each row remains constant and such that the wall possesses a planar inner and outer surface. 
     Because the proper laying of block is a time-consuming, labor-intensive and skilled task, alternative block structures, configurations and systems have been developed which address one or more of these problems. One approach has been to provide mortarless blocks, i.e., blocks which interlock in a secure manner without the need for the addition of mortar or other bonding material between individual blocks. The blocks are usually constructed such that each possesses both male and female mating components, such as a pair of longitudinal channels on the top and a pair of longitudinal ridges on the bottom, so that the channels of the lower block receive the ridges of the block set above it. Other projection/recess or tongue/groove mating configurations are also known and utilized. Many systems use the interlocking blocks merely as forms to receive poured concrete, with the blocks often formed of polystyrene foam. Examples of such systems are seen in U.S. Pat. No. 5,901,520 to Abdul-Baki, U.S. Pat. No. 5,894,702 to Stenekes, U.S. Pat. No. 5,623,797 to Gravier et al., U.S. Pat. No. 5,457,926 to Jensen, U.S. Pat. No. 4,186,540 to Mullins, and U.S. Pat. No. 3,534,518 to Zagray. Mortarless systems have met with rather limited success, however, since conventional block-making equipment cannot produce blocks with less than a {fraction (1/16)} inch variation in height between individual blocks. Even such a small variation is enough to cause unacceptable deviation from plumb after only 3 or 4 courses. The use of mortar between blocks compensates for this variation, since the height of the mortar can be varied to properly position each block at the proper height. Mortar also serves to seal joints and provides a measure of flexural strength, so eliminating mortar is not necessarily beneficial. 
     Other systems of interlocking or aligning blocks have been developed where mortar or grout is still used in some degree to join adjacent blocks in a more secure manner beyond that provided by the interlocking or aligning structures alone. For example, Brooke in U.S. Pat. No. 800,067 discloses blocks having longitudinal tongue and groove alignment means along the edges, where mention is made that cement or grout is utilized to construct the wall. Buyer in U.S. Pat. No. 2,019,653 shows blocks having centralized raised bosses and corresponding sockets for alignment, where the bosses sockets have a flat surface bounded by two sloping lateral surfaces, where the flat and sloping surfaces abut directly when the blocks are stacked. A recess is provided along the horizontal joint between courses for receiving mortar or grout after the blocks have been stacked. Finally, Huag et al. in U.S. Pat. No. 4,787,189 shows another type of interlocking blocks where the center of the blocks have longitudinal tongue and groove configurations. A problem with the Brooke and Huag et al. systems is that both still require skilled application of the mortar in the right amount to the proper locations, since there is no provision in the designs to allow for excess or misplaced mortar. Any mortar which inadvertently falls into the tongue and groove areas will interfere with and prevent proper alignment of the blocks, necessitating the lifting of the block and removal of the excess material. The Buyer system is in effect a mortarless system, with all the inherent problems of those types, since the mortar or grout is not applied until after the blocks have been stacked. Should the mortar be applied prior to stacking, the Buyer design likewise provides no margin for application error, since the sloped surfaces make direct contact when the blocks are stacked and excessive or misplaced mortar will interfere with the proper fit and alignment. 
     Another similar type of self-aligning building block system is disclosed in my U.S. Pat. No. 6,223,493 issued May 1, 2001. The invention therein is a self-aligning cementitious block and a wall system of such blocks stacked and joined by mortar to form a vertically oriented wall structure, where the block comprises alignment means which correctly align the block relative to the blocks upon which it is stacked such that the side walls are parallel to the side walls of the lower blocks. The alignment means comprise projection members and recess members of corresponding configuration, where the projection members preferably extend downward from the two end walls and the middle wall a distance below the lower longitudinal edges of the side walls, and where the recess members are positioned on the tops of the end walls and middle wall, the recess members of inferior or lower blocks receiving the projection members of a superior or upper block stacked thereupon. Starter blocks with a flat underside and corner blocks are also provided. Such a design for the blocks has been found to be difficult to manufacture, and the extended projection member is subject to breaking if mishandled. Furthermore, the design is more difficult to stack on a pallet in a compact manner. 
     It is an object of this invention to provide a cementitious building block and system where the blocks are self-aligning and interlock to provide a wall structure having generally planar inner and outer wall surfaces, where the courses are easily maintained at plumb as the height of the wall increases. It is a further object to provide such a block and system where the blocks can be properly stacked in a fast and non-complicated manner, such that the task can be performed by relatively unskilled labor having only the most basic of mortar application skills. It is a further object to provide such a system where mortar is utilized to join adjacent blocks, such that the joints are sealed, flexural strength is enhanced, and variations in block height can be compensated for. These and other objects not expressly stated will be apparent based on the disclosure and description of the invention, its best mode and preferred embodiment, as set forth below. 
     SUMMARY OF THE INVENTION 
     The invention is a self-aligning cementitious block and a system of such blocks stacked and joined by mortar to form a vertically oriented wall structure, where the block comprises alignment means which correctly align the block relative to the blocks upon which it is stacked such that the side walls are parallel to the side walls of the lower blocks. The alignment means comprise tongue members and groove members of corresponding configuration, where the tongue members extend downward from the two end walls and the middle wall a distance below the lower longitudinal edges of the side walls, and where the groove members are positioned on the tops of the end walls and middle wall, the groove members of inferior or lower blocks receiving the tongue members of a superior or upper block stacked thereupon. 
     The tongue members comprise a planar, horizontally disposed, lower edge bounded by a pair of short, outwardly inclined first sloping side walls, and a pair of short, outwardly inclined second sloping side walls connecting the first sloping side walls to the lower edges or bottom of the block. The groove members comprise a planar lower edge or bottom bounded by a pair of short, outwardly inclined first sloping side walls, and a pair of short, outwardly inclined second sloping walls connecting the first sloping side walls to the upper edges or top of the block. The second sloping side walls on both the tongue member and groove member are more sloped or inclined, i.e., more horizontally or less vertically disposed, than the first sloping side walls. The depth of the groove members is less than the vertical height or length of the tongue members, and the lateral width of the tongue members is slightly less than the width of the groove members, such that when a block is placed atop another block or set of blocks the tongue member sloping walls and groove member sloping walls loosely mate. The alignment means insure that the blocks are properly oriented and the mortar bonds the blocks together. 
     Corner blocks are provided in the system, the corner blocks being identical to the standard block in regard to the tongue members on the end walls and the middle wall, and to the groove members on one end wall and the middle wall. The opposing end wall is an exterior end wall and has a planar upper lateral edge rather than a groove member. A pair of groove members of identical configuration are positioned in the side walls of the block between the middle wall and the end wall with the planar upper lateral edge. To form a corner, each superior corner block is positioned perpendicular to the inferior corner block, such that the tongue members extending beneath the middle and exterior end walls of the superior block align with the groove members positioned in the side walls of the inferior block. In this manner the exterior end walls present a solid square surface to the outside of the corner in conjunction with the solid side walls of the standard blocks. Starter blocks having a planar lower surface with no tongue members are provided to form the first or base course of blocks. 
     In assembling the block wall structure, the worker applies mortar to either the upper edges of an inferior block or row of blocks or the lower edges of the block to be joined, as well as to the end wall of the adjacent block or the block to be joined. The worker sets the tongue members into the groove members, such that the block is correctly aligned relative to the inferior blocks and adjacent block. Any excess mortar placed into the joint recess is extruded outward by the weight of the block due to the combination of the first and second sloping side walls of the tongue and groove members, where it is easily removed, and any mortar mistakenly deposited in the groove members are on the tongue members will be expressed outwardly due to the chute effect created by the sloping side walls, thus preventing the excess mortar from interfering with proper alignment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the standard block of the invention. 
     FIG. 2 is a top view of the standard block. 
     FIG. 3 is an end view showing a superior block seated on an inferior block. 
     FIG. 4 is a side view showing a course of blocks seated on a starter block. 
     FIG. 5 is a perspective view of a corner block, with the occluded features shown in outline. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the drawings, the invention will now be described in detail with regard for the best mode and the preferred embodiment. In general, the invention comprises blocks which are configured to self-align when stacked into a wall configuration so that each successive course or row of blocks is properly aligned with the lower course or row of blocks to provide generally planar front and back wall surfaces. The blocks are provided with alignment means comprising projection or tongue members and recess or groove members such that alignment occurs in a tongue-and-groove manner. As discussed herein, the tongue members are shown to be on the bottom of the block and the groove members are shown to be on the top of the block, but it is to be understood that this is purely a matter of engineering choice and the blocks can also be configured with the tongue members disposed on the top and the groove members on the bottom of the blocks, i.e., the blocks can be inverted. Specially configured corner blocks and starter blocks are provided to complete the system whereby right angle corner walls can be constructed. The blocks are joined by mortar or other bonding material to form the finished structure. It is preferred that the blocks be formed of a cementitious material, such as cement or concrete, but any material known in the industry which is structurally suitable for construction of building blocks to support a load or form a lateral barrier may be utilized. In addition, while the dimensions of the blocks discussed herein are preferably generally equal to those of the standard building blocks most commonly used in the industry, it is to be understood that the dimensions may be varied in that it is the overall configuration of the block which is of most importance. 
     The main block configuration is shown in FIGS. 1,  2  and  3 , where the block  10  is seen to comprise a pair of opposing, parallel side walls  11 , a pair of opposing, parallel end walls  12  joined at right angles to the side walls  11 , and preferably a middle wall  13  extending perpendicularly between and joining the side walls  11  and centered at the midpoint between the end walls  12 . The side walls  11  are generally rectangular in overall shape with a smooth or textured external surface. The blocks  10  have a pair of upper edges  14  and a pair of lower edges  15  extending from end wall  12  to opposing end wall  12  and partially in the lateral direction along the end walls  12  and the middle wall  13  to define a generally E-shaped configuration, with the upper and lower edges  14  and  15  preferably presenting flat surfaces for receipt of mortar  99 . Suitable and common dimensions for the side walls  11  are about eight inches in height and about sixteen inches in length, with the outer distance between opposing side walls  11  being about eight inches, such that the dimensions of the exposed side walls  11 , the thickness of the block  10  and the height of the block  10  are generally equal to the dimensions of commonly known building blocks. A wall thickness of about one inch for the side walls  11  and end walls  12  is suitable, with the middle wall  13  preferably having a larger thickness dimension of about two inches. 
     The block  10  is provided with alignment means  20  which acts to automatically align the block  10  in proper relation to the blocks  10  in the course below it. The alignment means  20  aligns the block laterally, such that the side walls  11  are parallel to the side walls of lower blocks  10 . The alignment means  20  on a block  10  comprises tongue members  30  which extend beneath or form the lower portion of the end walls  12  and middle wall  13 , and corresponding groove members  40  which occupy or form the upper portion of the end walls  12  and middle wall  13 . The tongue members  30  and groove members  40  are disposed laterally between the lower edges  15  and upper edges  14 , respectively. The tongue members  30  extend below the side walls  11 . 
     The tongue members  30  each comprise a generally planar, horizontally disposed, tongue lower edge  32 , a pair of opposing, outwardly inclined, first sloping side walls  33  joined to said lower edge  32 , and a pair of opposing, outwardly inclined, second sloping side walls  34  extending between the first sloping side walls  33  and the generally horizontally disposed lower edges  15  of the side walls  11 . The first sloping side walls  33  are more vertically oriented than the second sloping side walls  34 . Most preferably, the first sloping side walls  33  slant outwardly approximately seven degrees relative to vertical, i.e., forming an interior angle of approximately 97 degrees relative to the lower edge  32 . Suitable dimensions are a height of about 0.375 inches for the tongue first sloping side walls  33 , a lateral width of about 0.046 inches for the tongue first sloping side walls  33 , a height of about 0.375 inches for the tongue second sloping side walls  34 , a lateral width of about 0.350 inches for the tongue second sloping side walls  34 , and a lateral width of about 2.533 inches for the tongue lower edge  32 . The overall height of the tongue member  30  is about 0.750 inches beyond the lower edges  15 , each of which extend outward in the horizontal direction about 2.125 inches. 
     The groove members  40  each comprise a generally planar, horizontally disposed, groove bottom  42 , a pair of opposing, outwardly inclined, first sloping side walls  43  extending upward from the groove bottom  42 , and a pair of opposing, outwardly inclined, second sloping side walls  44  which extend between the first sloping side walls  43  and the generally horizontally disposed upper edges  14 . The first sloping side walls  43  are more vertically disposed than the second sloping side walls  44 . Suitable dimensions are a height of about 0.188 inches for the groove first sloping side walls  43 , a width of about 0.023 inches for the groove first sloping side walls  43 , a height of about 0.188 inches for the groove second sloping side walls  44 , a width of about 0.188 inches for the groove second sloping side walls  44 , and a lateral width of about 2.658 inches for the groove bottom  42 . The overall depth of the recess member  40  is about 0.376 inches beneath the upper edges  14 , which are each about 2.273 inches in lateral width. The lateral width of the tongue lower edges  32  and groove bottoms  42  are chosen such the tongue members  30  fit relatively snugly into the groove members  40  in mating manner such that relative lateral movement is precluded. 
     The tongue member  30  is of greater height than the depth of the groove member  40 , as it is necessary that the tongue member  30  be longer in the vertical direction than the groove member  40  so that it will extend into the groove member  40  once mortar  99  is applied between the blocks  10 . As shown, the tongue members  30  are preferably approximately twice the vertical dimension of the groove members  40 . Because of this configuration, when a block  10  is placed onto a lower course of blocks  10 , as shown in FIG. 4, only the first sloping side walls  33  of the tongue members  30  of the upper block  10  will contact the first sloping side walls  43  of the groove members  40  of the lower blocks  10 . The excess length of the tongue members  33  maintains the tongue second sloping side walls  34  a short distance above and separated from the groove second sloping side walls  44  of the blocks  10  below, thereby creating interior chute recesses  51  of increasing separation in the outward direction between the blocks  10 . Likewise, the excess length of the tongue members  30  maintains the lower edges  15  of the upper block  10  a short distance above the upper edges  14  of the lower blocks  10 , thereby defining a joint recess  52  to receive the mortar  99 . These features are important to account for excess or improperly applied mortar  99 . To bond a block  10  to the lower course of blocks  10 , mortar  99  is applied along the upper edges  14  of the lower blocks  10 , as well as to the end wall  12  of the block  10  being laid which will abut the adjacent block  10  already positioned in the same course. When the block  10  is set onto the lower course of blocks  10  by aligning the tongue members  30  into the groove members  40 , the block  10  is aligned properly in the lateral direction. Any excess mortar  99  will be pressed outward from the joint recesses  51  to be removed by hand or inward into the open area between the sloping walls  34  and  44 . In addition, if any mortar  99  accidentally falls into the groove member  40 , the conjunction of the first sloping side walls  33  and  43  and the conjunction of the second sloping side walls  34  and  44 , the combinations defining an interior chute  52  which increases in separation distance in the outward direction, the mortar  99  will be displaced into the larger joint recess  51 , which prevents the excess mortar  99  from interfering with the proper fit between the block  10  and the lower course of blocks  10 , both vertically and horizontally, since the excess mortar  99  rests harmlessly within the joint recesses  51 . 
     Unless the lowermost course of blocks  10  is set into wet concrete or cement, the system requires the use of starter blocks  70 , as shown in FIG. 4, which have a flat lower edge  71  with no tongue members  30  extending beneath the block  10 . The first course of a wall would consist of starter blocks  70  placed onto a flat support slab or floor. The remainder of the courses would consist of blocks  10  as described above. 
     In order to provide a simple system for constructing corners using the blocks  10  as described above, corner blocks  100  as shown in FIG. 5 are provided. The corner blocks  100  have some features identical to the blocks  10 . At what will be the interior end of the corner block  100 , an interior end wall  112  is provided with alignment means  120  comprising a tongue member  130  comprising a lower edge  132 , first sloping side walls  133 , second sloping side walls  134 , and a groove member  140  comprising a lower edge  142 , first sloping side walls  143  and second sloping side walls  144 . A middle wall  113  has equivalent tongue and groove members  130  and  140 . Side walls  111  have upper edges  114  and lower edges  115 . For half of the corner block  100 , the interior half which will abut one of the standard blocks  10  in a particular course, these components are identical to the equivalent components of the block  10  as described in detail previously. The other half of the corner block  100  is configured much differently. The opposite end wall  217 , which will be exposed to the exterior side of the corner, has a generally flat and planar upper lateral edge  216  which forms the lower boundary to receive mortar  99 , while the lower portion of the exterior end wall  217  has a tongue member  130  comprising a tongue member  131  with a lower edge  132 , first sloping side walls  133  and second sloping side walls  134 , the projection member  130  being configured the same as the projection members  130  on the middle wall  113  and interior end wall  112 . 
     A pair of opposing lateral groove members  240  are positioned on the upper edge  114  between the middle wall  113  and the exterior end wall  217 , such that the side walls  111  of the corner block  100  do not present a rectangular perimeter. The lateral groove members  240  each comprise a lower edge  242 , first sloping side walls  243  and second sloping side walls  244 . The lateral groove members  240  are structured and dimensioned to match the other groove members  140  and  40 , so that they can receive the projection members  130  in the same manner as regular blocks  10 . 
     A corner is constructed by building a course with one corner block  100  positioned with the exterior end wall  217  disposed at the end of the course where the corner is to be formed. A standard block  10  is mounted at a right angle to the corner block  100 , abutting it in normal manner. The upper course is laid by positioning a corner block  100 , again with the exterior end wall  217  disposed at the end of the upper course, at a right angle to the lower corner block  100 . This is accomplished by placing the tongue members  130  of the upper corner block  100  into the lateral groove members  240  of the lower corner block  100  and into the groove members  40  of the adjacent block  10  positioned in the same course as the lower corner block  100 . The corner can be formed in either direction. The tongue member  130  of the exterior end wall  217  of the upper corner block  100  will align with the exterior lateral groove member  240  of the lower corner block  100 . The tongue member  130  of the middle wall  113  of upper corner block  100  will align with both the interior lateral groove member  240  of the lower corner block  100  and the groove member  40  of the abutting end wall  12  of the lower block  10 . The tongue member  130  of the interior end wall  112  of the upper corner block  100  will align with the groove member  40  of the middle wall  13  of the lower block  10 . The upper lateral edge  216  of the lower corner block  100  extends beneath a portion of the lower edge  115  of the upper corner block  100  to form the recess to receive mortar  99 . Each course is then formed by disposing the upper corner block  100  perpendicularly to the lower corner block  100 . 
     It is understood that equivalents and substitutions to certain elements set forth above may be obvious to those skilled in the art, and the true scope and definition of the invention therefore is to be as set forth in the following claims.