Abstract:
A retaining block wall, retaining blocks, and a retaining block manufacturing method result in a structural wall with two mechanical interlocks and water management systems.

Description:
BACKGROUND 
       [0001]    There is a significant need for structurally sound and aesthetically attractive retaining walls made from manufactured blocks. In the past, natural stone boulders, cinder blocks, and other inferior blocks have been used with limited success. 
       SUMMARY 
       [0002]    A retaining block wall, retaining blocks and a related manufacturing method have been invented. 
         [0003]    The retaining wall block itself may include a combination of one or more of the following features:
   (a) a hollow core to facilitate water migration within the interior of a wall made of the blocks, from top to bottom, via gravity flow;, and which makes the block lighter and uses less concrete to manufacture than a solid block,   (b) a water trough at the bottom of the blocks so that any wall constructed using the blocks has incorporated within it a water trough to move water away from the retaining wall, thus mitigating the effects of hydraulic pressure and erosion, allowing water to go into a drainage device if desires, such as a gravel field, perforated pipe, etc.,   (c) an integral top nub and bottom receptacle on the blocks so that blocks, once stacked into a retaining wall, are mechanically interlocked by the block material itself and without the need for separate connecting mechanisms such as rebar, etc.,   (d) location of the nub on the top of each block and the receptacle on the bottom of each block so that no special blocks are needed for construction of the bottom of a retaining wall,   (e) the receptacle (for an interconnecting nub) being formed on the blocks as a lateral groove across the block so that workers can assemble the blocks with any desired offset,   (f) the nub and receptacle being formed with a predetermined batter, such as 5 degrees (about 9 percent) to facilitate the blocks being used to form a high wall with ample structural integrity,   (g) an integral core on a wall formed by the blocks, the wall having sloped walls, the walls sloping from narrow to wide from top to bottom so that gravel will completely fill the block cores if gravel is used, thereby creating a mechanical interlock by way of gravel interference between vertically adjacent blocks,   (h) angular side walls on the blocks so that they can readily be used for constructing retaining walls with non-planar shapes, and   (i) an outer wall aesthetic pattern in order to present an attractive view in a finished retaining wall.   
 
         [0013]    A retaining block wall made using the blocks will have these and other features that distinguish them from the prior art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0014]      FIG. 1  depicts a top view of a top retaining wall block without nubs. 
           [0015]      FIG. 2  depicts a top view of a retaining wall block with nubs. 
           [0016]      FIG. 3  depicts a side view of a top retaining wall block of  FIG. 1 . 
           [0017]      FIG. 4  depicts a side view of the retaining wall block of  FIG. 2 . 
           [0018]      FIG. 5  depicts a side view of a retaining wall made with retaining wall blocks. 
           [0019]      FIG. 6  depicts a top view of a curved retaining wall made with retaining wall blocks, showing a tight convex curve made as a result of angled blocks (such as a 16 ft. radius). 
           [0020]      FIG. 7  depicts a frontwise perspective view of a mold for making retaining wall blocks. 
           [0021]      FIG. 8  depicts a rearwise perspective view of a mold for making retaining wall blocks. 
           [0022]      FIG. 9  depicts a rear view of a mold for making retaining wall blocks. 
           [0023]      FIG. 10  depicts a side view of a mold for making retaining wall blocks. 
           [0024]      FIG. 11  depicts a top view of a mold for making retaining wall blocks. 
           [0025]      FIG. 12  depicts a front view of a mold for making retaining wall blocks. 
           [0026]      FIG. 13  depicts a side sectional view of a mold for making retaining wall blocks after a block has been cast with the mold core being disengaged or removed. 
           [0027]      FIG. 14  depicts a side sectional view of a mold for making retaining wall blocks after a block has been cast with the mold core (such as a tapered barrel) disengaged and mold sides opened so that the block can be lifted from the mold and put into inventory or taken to a construction site. 
       
    
    
     DETAILED DESCRIPTION  
       [0028]    Referring to  FIGS. 1- 4 , both a retaining wall block  102  ( FIGS. 2 and 4 ) and a special top retaining wall block  101  ( FIGS. 1 and 3 ) are depicted. Each block has an outer periphery wall  101   b  and  102   b  surrounding a hollow inner core  101   a  and  102   a.  Each block has a top  101   c  and  102   c,  and a bottom  101   d  and  102   d.  On its top, each block that is not a top block, such as  102 , has a nub  102   e  for insertion into block bottom receptacle or channel  101   f  or  102   f.  Insertion of the nub into the receptacle forms a mechanical interlock between the blocks. Block sides  101   h,    101   i,    102   h,  and  102   i  may be angled as desired, such as being angled toward the front as shown, to facilitate placement of concrete of the blocks in a configuration that creates a non-planar retaining wall. The top block may include a lip  101   j  for further retention and aesthetic purposes. The lip allows the material being retained, such as earth, to be brought over the top of the block and against the angled portion shown in the figure, if desired, to conceal the top of the block. Optionally the blocks may have a pickup joint  101   k  and  102   k.    
         [0029]    Referring to  FIGS. 5 and 6 , a retaining wall  501  constructed of the invented retaining wall block is depicted. The example wall has a top row of top retaining wall blocks  101  without nubs. The example wall also has three mechanically interlocked retaining wall blocks  102  stacked with a positive batter for structural stability, however a wall of the user&#39;s design could be as high or low as desired. Each block with a nub  102   e  has the nub inserted into a receptacle (easily seen at  102   f ) to create the mechanical interlock which creates a stable wall. A mechanical interlock between two blocks, one on top of the other, is created by the block material itself (such as concrete) rather than by a separate device such as rebar or a bolt. Further, the block bottom receptacle from a series of blocks forms a channel that accommodates water flow along the bottom of any row of blocks and along the bottom of a retaining wall made from blocks to facilitate runoff and avoid erosion. Viewing the wall from the top such as in  FIG. 6 , the voids in the interiors of the blocks create generally vertical hollow columns which can be filled with gravel or other filler material for creating of a unified interlocked block retaining wall. Those generally vertical columns also permit water to flow vertically down through the blocks to the channel mentioned above. This permits water to be drained off from the retaining wall to avoid hydraulic pressure buildup, ground softening, freezing and erosion. 
         [0030]    As desired, the front face of the blocks may include an aesthetic design  101   g  and  102   g  to create an attractive retaining wall when construction is complete. 
         [0031]    The retaining wall blocks are stackable to create a structurally sound retaining wall. Location of the nub and receptacle features for a predetermined batter, such as 5 degrees, facilitate the blocks being used to form a high wall with structural integrity. The blocks may have an internal core that has sloped walls if desired, the walls sloping from narrow to wide from top to bottom so that the vertical columns created by those voids will fill completely with gravel or other fill material, thereby creating a second mechanical interlock mechanism by way of gravel or fill interference between vertically adjacent blocks. The blocks may be manufactured with angled sides so that they can readily be used to build retaining walls with non-planar shapes. 
         [0032]    An example of dimensions of the blocks is 2′×4′×3′ (height×length×depth). This has been found to provide excellent structural integrity. Use of a ration of block depth to height, where the block depth is at least 125% of block height, or at least about 150% of block height, contributes to stability, as do the mechanical interlock of the nub and receptacle as well as the second mechanical interlock of the fill material such as gravel. 
         [0033]    Use of blocks with hollow cores permits installation of fencing directly on top of a wall made from the blocks. With prior art devices, fences were often offset from the retaining wall, resulting in loss of usable real estate, difficulties with lawn mowing and upkeep, and aesthetic impairment. 
         [0034]    Referring to  FIG. 7-14 , a mold  701  for making the invented retaining wall blocks is depicted. The mold  701  includes a mold body  702  and a core  703 . The mold core projects into the mold body in order to take up space so that completed block has a hollow inner core of the dimensions and geometry desired. The inner core forms one side of the mold. The mold has two sides  707  and  708  which can fold into place for block formation and fold away from the formed block for block removal. The mold core  703  may be drawn into the mold and pushed back out of the mold by use of a hand crank, rotatable screw or bolt  710  projecting through bore  706 . The hand crank is a dual thrust stripping assembly. Cranked one way, the hand crank draws the mold core in tight, and turned the other way it pushes the core from the interior of the mold. A fixed opposing nut  780  or other opposing device may be used to push or pull against. Also, if desired, a secondary mold stripping mechanism  798  may be employed. In this case the secondary mold stripping mechanism is merely a bolt which when turned presses against the mold body to provide additional tension withdrawing the mold core from the mold. By use of a dual stripping assembly such as crank  710  and a secondary mold stripping mechanism, removal of a mold core from a formed concrete block is possible, easy and convenient. Since the sides of the core  703  are sloped in a positive fashion with respect to the direction in which the core is withdrawn from the mold, the mold core easily breaks free from a molded concrete block. The mold core  703  also has the ability to pivot with respect to a lower pivot point  720  by use of pivot frame  721  to which the mold core  703  is attached. Movement of the mold core into and out of the mold may be facilitated by use of a mold core track  750  and wheels or bearings in that track  760  to cause the mold core to move more easily. The front of the mold body  702  can pivot away from the molded block at a pivot point  770  if desired. The mold may have a bottom  729  to hold concrete when the block is forming. As an example, a polyurethane form liner may be used to form a texture on the block. Use of this mold assembly results in a formed concrete block  799  ready to use. 
         [0035]    As depicted, the mold may be used to form a block in face-down fashion. This facilitates formation of an aesthetic pattern with deep relief on the block and allows air bubbles to rise away from the block face. 
         [0036]    The mold may be made from any desired material, such as metal, wood, plastic, composites or other materials. The mold geometry can be adjusted to create the desired tapers, channels, nubs and receptacles on the finished retaining wall blocks. 
         [0037]    When in use, the mound forms a block by a particular method which can be altered per the user&#39;s requirements. Example steps in the method include obtaining a suitable mold, placing the mold core into the mold, placing concrete into the mold, allowing the concrete to cure into a retaining wall block, removing the mold core from the mold, pivoting the mold sides away from the block, and removing the block from the mold. The mold core may be moved into place in the mold interior with a pivot and pivot frame, with a track and rollers and bearings, or by use of both. The mold core may be tightened into place and may be forced out of place, as needed. 
         [0038]    While the present invention has been described and illustrated in conjunction with a specific embodiment, those skilled in the art will appreciate that variations and modifications may be made without departing from the principles of the invention as herein illustrated, described, and claimed. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiment is to be considered in all respects as only illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.