Abstract:
A mold assembly is used for manufacturing a ventilated building block. The ventilated building blocks are configured such that adjacent stacked blocks are inverted and reversed, thereby establishing front-to-back air passages that do not provide a sight line and prevent rain from passing through while enabling air ventilation.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/878,294, filed Sep. 16, 2013, the entire content of which is herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a ventilated building block construction and to mold components for a machine for making the block. 
         [0003]    Currently, typical concrete ventilating blocks are formed with straight, internal passages extending vertically through the block, such that when plural blocks are stacked, a ventilating “chimney” is formed. These and other block constructions are well represented in the patent literature. For example, U.S. Pat. No. 2,137,153 discloses ventilated wall blocks that are stacked vertically in an alternately inverted orientation, establishing both vertical and horizontal vent passageways. In U.S. Pat. No. 7,096,634, a block is disclosed that, when stacked, creates vertical vents or cores. Still other block constructions are disclosed in U.S. Pat. Nos. 1,758,757; 2,624,193; and 4,823,530. A ventilated building block and mold core and stripper shoe components for forming the ventilated building block are described in a commonly-owned U.S. Pat. No. 7,757,451, the entirety of which is incorporated herein by reference. 
         [0004]    The block described in the &#39;451 patent includes an elongated center portion flanked by a pair of substantially parallel side walls oriented substantially perpendicularly to the center portion, the center portion having a first vertical wall and a second sloped wall. The sloped wall extends between a relatively thicker bottom wall of the center portion and a relatively thinner top wall. A horizontal shoulder extends across the sloped front wall at a height substantially equal to the height of the side walls, such that the shoulder lies in the same horizontal plane as the upper edges of the side walls. Accordingly, the upper portion of the block assumes a substantially triangular cross-sectional shape. 
         [0005]    Another existing design is described in GB 782,754. The building blocks in the GB &#39;754 patent are “precast” (as stated in the patent). Precast products are made by filling a mold with concrete and leaving it for a specific time (usually a minimum of 24 hours), or depending on the design of the item being precast, a couple of days, before stripping it from the mold. The GB &#39;754 design would require anywhere from two to six days before stripping from the mold. The GB &#39;754 design, however, cannot be manufactured on a conventional concrete block machine as the design requires an “upper” and a “lower” core block. The lower core block would prevent or make it impossible to strip the block from the mold as is done on a block machine. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0006]    In accordance with an exemplary but nonlimiting embodiment of this invention, there is provided a modified ventilated building block along with mold core and stripper-shoe components for a block manufacturing machine for forming the modified ventilated building block. In the modified block, the upper portion of the block between and above the side walls now may have a substantially square cross-sectional shape. The sloped wall may alternatively have a consistent slope from bottom to top. Additionally, the horizontal shoulder has been eliminated to facilitate manufacture. Still further, the upper portion may be slightly inwardly offset from the side walls. 
         [0007]    The design can advantageously be made on an automated concrete block machine that is configured to produce a block depending on its design in seconds, e.g. ten seconds per cycle. Also, because the concrete is compressed under vibration, the block can be five to ten times stronger than the precast unit. This additional strength is also achieved by using less cement (the most costly factor in concrete) than its precast counterpart. 
         [0008]    In order to manufacture the modified block, new mold core and stripper shoe components are illustrated and described herein. 
         [0009]    In an exemplary embodiment, a mold assembly provides for machine molding a ventilated building block. The building block is cooperable with an adjacent building block in a stacked, inverted and reversed orientation relative to the adjacent building block. The building block may include an elongated center portion flanked by a pair of substantially parallel side walls oriented substantially perpendicularly to the center portion. The center portion may project upwardly beyond upper edges of the side walls, and the side walls may extend forwardly of a forward edge of the center portion. The mold assembly includes an outside division plate delimiting one of a rearmost side and a forwardmost side of the building block and an inside division plate delimiting one of the rearmost side and the forwardmost side of the building block. A core block portion is disposed between the outside division plate and the inside division plate and delimits a sloped front surface of the elongated center portion. A plate portion cooperable with the core block portion and disposed spaced from the one of the outside division plate or the inside division plate delimits the rearmost side of the building block and delimits a thickness of the center portion where the center portion projects upwardly beyond the upper edges of the side walls. A pair of return flanges positioned on opposite lateral sides of the core block portion delimit a width of the center portion where the center portion projects upwardly beyond the upper edges of the side walls. A stripper shoe assembly disposed outside of and above the return flanges delimits the upper edges of the side walls and a height of the center portion. 
         [0010]    The plate portion may extend laterally beyond opposite side edges of the core block portion. 
         [0011]    The stripper shoe assembly may include a stripper bar positioned adjacent the core block portion and delimiting the height of the center portion, and blocks positioned at opposite lateral ends of the stripper bar and oriented relative to the stripper bar such that the stripper shoe assembly defines a U-shape. The blocks delimit the upper edges of the side walls. The mold may also include a plunger to which the stripper shoe assembly is bolted that is displaceable relative to the outside division plate and the inside division plate. In one arrangement, each of the blocks includes two discrete block elements separately attachable to an underside of the plunger. The stripper bar may include a planar plate member that is thinner than the blocks, where the bar is generally rectangular in cross-section. 
         [0012]    The core block portion and the plate portion may be shaped and positioned relative to each other such that the sloped front surface of the elongated center portion transitions to a vertical wall portion substantially where the elongated center portion projects upwardly beyond the upper edges of the side walls. In another arrangement, the core block portion and the plate portion are shaped and positioned relative to each other such that the sloped front surface of the elongated center portion extends from a bottom of the elongated center portion to a top of the elongated center portion. 
         [0013]    The return flanges may be positioned relative to the core block portion and the stripper shoe assembly such that the elongated center portion is offset inwardly from the side walls. 
         [0014]    The mold assembly may also include a center division plate interposed between the outside division plate and the inside division plate that defines two mold chambers for concurrently molding two building blocks. 
         [0015]    The inside division plate may delimit the other of the rearmost side and the forwardmost side of the building block. 
         [0016]    In another exemplary embodiment, a ventilated building block is manufactured using the mold assembly according to the described embodiments. 
         [0017]    In yet another exemplary embodiment, a method of manufacturing a ventilated building block using the mold assembly according to the described embodiments includes the steps of positioning and securing the mold assembly in a mold box; pouring a block material into the mold box; vibrating the mold box; compressing the block material with the stripper shoe assembly; and stripping the molded ventilated building block from the mold assembly with the stripper shoe assembly. The vibrating step and the compressing step may be performed concurrently. 
         [0018]    In still another exemplary embodiment, a ventilated building block is cooperable with an adjacent building block in a stacked, inverted and reversed orientation relative to the adjacent building block. The ventilated building block includes an elongated center portion flanked by a pair of substantially parallel side walls oriented substantially perpendicularly to the center portion, where the center portion projects upwardly beyond upper edges of the side walls, and where the side walls extend forwardly of a forward edge of the center portion. The elongated center portion includes a sloped front face and a substantially vertical rear face, where the sloped front face is oriented at an initial angle relative to the substantially vertical rear face, with the initial angle being a maximum angle of the sloped front face relative to the substantially vertical rear face. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention will now be described in detail in connection with the drawings identified below. 
           [0020]      FIG. 1  is a front perspective view of a ventilated building block in accordance with an exemplary but nonlimiting embodiment of the invention; 
           [0021]      FIG. 2  is a front elevation view thereof; 
           [0022]      FIG. 3  is a rear elevation view thereof; 
           [0023]      FIG. 4  is a top plan view thereof; 
           [0024]      FIG. 5  is a bottom plan view thereof; 
           [0025]      FIG. 6  is a left side elevation view thereof; 
           [0026]      FIG. 7  is a right side elevation view thereof; 
           [0027]      FIG. 8  is a section view taken along the line  8 - 8  in  FIG. 2 ; 
           [0028]      FIG. 9  is an exploded perspective view of a mold core, division plate and stripper shoe assembly used in the production of blocks as shown in  FIGS. 1-8 ; 
           [0029]      FIG. 10  is an exploded perspective view of an alternative mold core and stripper shoe assembly; 
           [0030]      FIG. 11  is a perspective view of the mold assembly of  FIG. 9  in partially assembled form, but with the mold core not visible in this view; 
           [0031]      FIG. 12  is a perspective view of the mold assembly of  FIG. 10  in partially assembled form but with the mold core not visible in this view; 
           [0032]      FIG. 13  is a front plan view of stripper shoe components taken from  FIG. 9 ; 
           [0033]      FIG. 14  is an end view of the left-side component in  FIG. 13 ; 
           [0034]      FIG. 15  is a section view taken along the line  15 - 15  in  FIG. 16 ; 
           [0035]      FIG. 16  is a perspective view of the stripper shoe subassembly shown in  FIGS. 13-15 ; 
           [0036]      FIG. 16A  is a perspective view of an alternative end shoe for a stripper assembly; 
           [0037]      FIGS. 17-20  are views similar to  FIGS. 13-16  but in accordance with an alternative stripper-shoe assembly embodiment; 
           [0038]      FIG. 21  is a left end view of the core and division plates taken from  FIG. 9 , but shown in assembled relationship; 
           [0039]      FIG. 22  is a plan view of the components shown in  FIG. 21 ; 
           [0040]      FIG. 23  is a left end view of the mold core components shown in  FIG. 10 ; 
           [0041]      FIG. 24  is a plan view of the mold core components as shown in  FIG. 23 ; 
           [0042]      FIG. 25  is an end elevation of a mold core and division plate assembly in accordance with another exemplary embodiment; 
           [0043]      FIG. 26  is a plan view of the mold core and division plate assembly as shown in  FIG. 25 ; 
           [0044]      FIG. 27  shows the mold assembly in a mold box; 
           [0045]      FIG. 28  shows adjacent blocks oriented for constructing a wall; and 
           [0046]      FIG. 29  shows a wall constructed with the ventilated building blocks of the preferred embodiments. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0047]    With reference initially to  FIGS. 1-8 , a block  10  is formed (e.g., molded) to include an elongated center portion  12  with a pair of side walls  14 ,  16  arranged at either end of the center portion, and substantially perpendicular thereto. For ease of understanding, the block will be described as having a front and a back, top and bottom but it will be appreciated that these terms are relative, and are not intended to be limiting in any respect. Thus, for example, in  FIG. 1 , the view of the block  10  may be regarded as a top, right, front perspective view, with  FIGS. 2-8  described relative to  FIG. 1 . Accordingly, the reference to “top”, “bottom”, “front”, “back”, “left” and “right” refers to the block in  FIG. 1 , with its “front” side facing forward. It will be understood, however, that adjacent upper and lower blocks are reversed and inverted on assembly, so that the characterization of the block with reference to  FIG. 1  is for convenience only. 
         [0048]    The center portion  12  of the block has a flat, substantially vertical back wall or rear face  18  and a generally-sloped front wall portion or front face  20 . The back wall  18  is flush or co-planar with back (or first) edges  22 ,  24  of the side walls  14 ,  16 , respectively. The sloped front wall portion  20  extends between a relatively thicker bottom wall or base  26  to a relatively thinner top wall  28 . In one embodiment, the sloped front wall transitions to a vertical wall portion  21  at approximately the upper edges  30 ,  32  of the side walls. In an alternative embodiment, the sloped front wall has a consistent slope from bottom to top (shown in dashed line in  FIG. 8 ). Essentially, the sloped front wall portion  20  is oriented at an initial angle relative to the substantially vertical back wall  18 , where the initial angle from bottom to top is a maximum angle of the sloped front face  20  relative to the substantially vertical rear face  18 . The horizontal shelf or shoulder described in the &#39;451 patent has thus been eliminated. In one embodiment, the vertical wall portion is offset inwardly from the side walls by a few millimeters (e.g. 2-4 mm on each side). The exemplary offsets are shown at  25 ,  27 . The slope angle of the front wall portion  20  is preferably in the range of about 45-80° (shown at about 70° in  FIG. 5 , but the angle may vary with specific applications) relative to the horizontal bottom wall or base  26 . The terms “thicker” and “thinner” in this context relate to the depth dimension of the block. 
         [0049]    In this exemplary embodiment, the side walls  14 ,  16  extend beyond, i.e., forward of, the sloped front wall portion  20 , and the lower (or third) edges  30   a  and  32   a  of the sidewalls are flush with the bottom wall or base  26 . 
         [0050]    In the exemplary but non-limiting implementation of the invention illustrated in  FIGS. 1-8 , the block  10  may have a length (from side to side) of between about 190 mm and 460 mm (for example about 390 mm) and a depth (from front to back) of between about 80 mm and 200 mm (for example, about 90 mm) The total height of the block (from bottom to top) may be between about 80 mm and 240 mm (for example, about 107 mm) In the example shown, the vertical wall portion  21  extends about 32 mm above the side wall edges  30 ,  32 . The side wall thickness may be about 28 mm. The center portion  12  may have a depth of about 51 mm at the base  26  (in this embodiment, the forward or fourth edges  22   a,    24   a  of the side walls  14 ,  16  are forward of the center portion), and a depth of about 27 mm at the top edge  28 . 
         [0051]    It will be understood that the dimensions of the block may vary uniformly by scale, or differentially, depending on specific applications. It will also be appreciated that the block may be constructed of any suitable building materials including in addition to concrete, such materials as metals, plastics, resins, etc. 
         [0052]    Turning now to  FIGS. 9-24 , examples of mold assemblies that may be used to form the above-described block  10  are illustrated. The mold and stripper shoe components as described below may be used in otherwise conventional block manufacturing machines available from, for example, Besser Mfg. Co.; Colombia Machine Co.; Hess Machinery, LTD; Hess Maschinenfabrik GMBH &amp; Co.; Tiger International Inc.; and Tiger Machine Co. Ltd. Other companies may also provide similar machines or components for such machines. A mold assembly  48  designed especially for the block  10  may include a core  50 , an outside division plate  54 , an inside division plate  52 , and a pair of end liners (not shown) bolted together in a mold box  42  (see  FIG. 27 , four mold assemblies  48  shown in the mold box  42 ). The plunger (or stripper head)  56  and stripper shoe assembly  58  are bolted together and attached to a stripper head plate (not shown) that enables the plunger  56  and stripper shoe assembly  58  to move down into the mold box. Cut-outs  59  ( FIG. 11 ) in the plunger or stripper head  56  allow the plunger or stripper head to pass through the mold to strip the finished block out of the mold. The stripper shoe assembly includes the stripper bar  58 A and blocks  58 B at opposite ends of the bar  58 A. The bar  58 A and blocks  58 B are adapted to be bolted to the bottom of the plunger head  56  in the orientation shown in  FIG. 9 , with spaces provided between the bar  58 A and blocks  58 B for passing between the return flanges  61  on the core  50  described further below. The core  50  includes a laterally extending, vertically-oriented plate portion  60 , with the return flanges  61  secured at opposite ends thereof, and a core block portion  62  shaped to form the angled wall portion  20  of the block  10  and inside surfaces of the side walls  14  and  16 . The core  50  is attached to one of the two division plates  52  or  54 . For example, if core  50  is attached to outside division plate  54 , return flanges  61  will touch or attach to inside division plate  52 . This orientation would be reversed if the core  50  were attached to the inside division plate  52 . 
         [0053]    With continued reference to  FIG. 9 , the mold assembly provides for machine molding a ventilated building block. The resulting block is cooperable with an adjacent building block of identical construction in a stacked, inverted and reversed orientation relative to the adjacent building block. In one construction of the mold, the outside division plate  54  delimits one of a rearmost side and a forwardmost side of the building block. The inside division plate  52  delimits one of the rearmost side and the forwardmost side of the building block. In the arrangement shown in  FIG. 9 , the inside division plate  52  delimits the other of the rearmost side and the forwardmost side of the building block. The core block portion  62  is disposed between the outside division plate  54  and the inside division plate  52 . The core block portion  62  delimits the sloped front surface  20  of the elongated center portion  12 . The plate portion  60  is cooperable with the core block portion  62  and disposed spaced from the one of the outside division plate  54  or the inside division plate  52  that delimits the rearmost side  18  of the building block. The plate portion  60  delimits a thickness of the center portion  12  where the center portion projects upwardly beyond the upper edges of the side walls  14 ,  16 . The return flanges  61  are positioned on opposite lateral sides of the core block portion  62 . The pair of return flanges  61  delimit a width of the center portion  12  where the center portion projects upwardly beyond the upper edges of the sidewalls  14 ,  16 . The stripper shoe assembly  58  is disposed outside of and above the return flanges  61  and delimits the upper edges of the side walls  14 ,  16  and a height of the center portion  12 . 
         [0054]    The stripper shoe assembly  58  includes the stripper bar  58 A and blocks  58 B. The blocks  58 B are positioned at opposite lateral ends of the stripper bar  58 A and are oriented relative to the stripper bar such that the stripper shoe assembly  58  defines a U-shape. The stripper bar  58 A delimits a height of the center portion  12 , and the blocks  58 B delimit the upper edges of the side walls  14 ,  16 . The plunger  56  to which the stripper shoe assembly  58  is bolted is displaceable relative to the outside division plate  54  and the inside division plate  52 . 
         [0055]    The core block portion  62  and the plate portion  60  may be shaped and positioned relative to each other such that the sloped front surface  20  of the elongated center portion  12  transitions to the vertical wall portion  21  substantially where the elongated center portion  12  projects upwardly beyond the upper edges of the side walls  14 ,  16 . The core block portion  62  and the plate portion  60  may be shaped and positioned relative to each other such that the sloped front surface  20  of the elongated center portion  12  extends from a bottom of the elongated center portion to a top of the elongated center portion (shown in dashed line in  FIG. 8 ). The return flanges  61  may be positioned relative to the core block portion  62  and the stripper shoe assembly  58  such that the elongated center portion  12  is offset inwardly from the side walls  14 ,  16 . 
         [0056]      FIG. 10  illustrates an alternative embodiment where the stripper shoe assembly blocks  58 B are each comprised of two discrete block elements, separately attachable to the underside of the plunger head  56 . In addition, the vertically-oriented core plate portion  60 A extends laterally beyond the opposite side edges of the core block portion  62  and is formed with depending flange portions  63 . The return flanges  61 A remain in the same relative locations as return flanges  61  in the  FIG. 9  embodiment. 
         [0057]      FIG. 11  illustrates the plunger head  56 , stripper shoe assembly and block  10  as shown in  FIG. 9  after molding of the block  10  and separation from the division plates  52 ,  54 .  FIG. 12  is a view similar to  FIG. 11  but showing the components as described in connection with  FIG. 10  in the same state. 
         [0058]      FIGS. 13-16  show the stripper shoe components of  FIG. 9 . Specifically, the bar  58 A includes attachment holes  64 , and end blocks  58 B are each provided with attachment holes  66 ,  68  for securing these components to the underside of the plunger  66 . As shown in  FIG. 13 , the bar  58 A may comprise a planar plate member that is thinner than the end blocks  58 B. The bar  58 A may be generally rectangular in cross-section.  FIG. 16A  shows an alternative end shoe  70  for the stripper assembly that fits with a grooved end liner (not shown). 
         [0059]      FIGS. 17-20  show the alternative stripper shoe components from  FIG. 10 . In this embodiment, the center bar  58 A remains the same (including attachment holes  64 ), but the end blocks  58 B are divided into two discrete elements provided with respective attachment holes  66 ,  68 . The division of the end blocks accommodates the longer core plate portion  60 A of  FIG. 10 . 
         [0060]      FIGS. 21 and 22  illustrate the core assembly of  FIG. 9  in place, ready for molding, with division plates  52 ,  54  defining the width dimension of the block  10  to be molded. As indicated above, the arrangement of core components relative to the division plates  52 ,  54  may be reversed. 
         [0061]      FIGS. 23 and 24  show similar views as shown in  FIGS. 21 and 22 , but with the alternative core components shown in  FIG. 10 , and with the division plates removed. 
         [0062]      FIGS. 25 and 26  show similar views of the mold core as shown in  FIGS. 21 and 22 , but with a pair of core assemblies in back-to-back orientation, enabling simultaneous molding of a pair of blocks  10 . This arrangement requires the addition of a third or center division plate  53  separating the core block portions  62 . The plate  53  is similar to plates  52 , but with core portions attached to both sides of the plate. The center division plate  53  is interposed between the outside division plate  54  and the inside division plate  52  and defines two mold chambers for concurrently molding two building blocks. In the embodiment shown, the center division plate  53  is interposed between two core block portions  62  of the respective mold chambers. In this arrangement, the center division plate  53  thus delimits the forwardmost side of each of the building blocks in the respective mold chambers. Both the outside division plate  54  and the inside division plate  52  are thus positioned to delimit the rearmost side of each of the building blocks. 
         [0063]    For all embodiments, it will be appreciated that the dimensions of the core and stripper components may vary depending on the dimensions of the finished block  10 . The core plate portion  60  or  60 A may be placed anywhere on the upper edge of the core block portion  50 , and return flanges  61  or  61 A may vary in both length and height. 
         [0064]    As well understood by those familiar with the Besser and Columbia machines, in the block manufacturing process, a pallet plate (not shown) is moved into position below the mold box  42 , and concrete is poured into the box. The mold box  42  is vibrated to settle and uniformly distribute the concrete, and then the plunger head  56  and stripper shoe assembly  58  as described herein will be moved into the box to compress the concrete while under vibration, within the confines of the inner and outer division plates  52 ,  54 , end liners (not shown) and about the core  50 . After the block  10  has been formed, it will be stripped from the mold by removing the pallet, enabling the stripper shoe and plunger head to push the finished product out of the mold box. 
         [0065]      FIG. 28  shows adjacent blocks oriented for constructing a wall, and  FIG. 29  shows a wall constructed with the ventilated building blocks. A finished building block is cooperable with an adjacent building block of identical construction in a stacked, inverted and reversed orientation relative to the adjacent building block. The front faces  20  of inverted and reverse oriented blocks define a ventilation passage  36  through the block pair. As shown, the ventilation passage  36  is oriented from an outside surface of the block pair (on the right side in  FIG. 28 ) upward and inward to an inside surface of the block pair (on the left side in  FIG. 28 ) according to the angle of the front faces  20 . As shown in  FIG. 29 , the block pairs can be stacked to form a ventilated wall  40 . 
         [0066]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements.