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BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to the field of construction elements. In particular, the present invention provides an improved concrete block useful for constructing above and below grade walls.  
         [0003]     2. Description of the Related Art  
         [0004]     In applicant&#39;s issued U.S. Pat. No. 6,226,951, a robust concrete block is disclosed. Each block has a front panel, a rear panel, and webs that connect the front and rear. The blocks are notched at their ends to interfit and have complementary top and bottom profiles that also interfit. The blocks can be assembled without the aid of mortar, using specially designed corner blocks, into wall structures that can then be filled with concrete, resulting in a substantially monolithic concrete wall structure. The present invention is an improvement on the blocks described in U.S. Pat. No. 6,226,951 in that it provides an improved design allowing for freer flow of concrete into the wall structure and improved interlocking ends that will effectively anchor the blocks in place after concrete is poured.  
         [0005]     A modified interlocking end structure for dry stack blocks is shown in applicant&#39;s U.S. Pat. No. 6,591,569. In that patent, the blocks are provided with substantially Z shaped ends, to facilitate close end to end alignment of the blocks. Corner blocks with complementary Z shaped portions near the ends of their side panels are provided. The blocks of U.S. Pat. No. 6,591,569 fit together extremely well due to the interlocking of the Z shaped ends. However, the ends tend to be more fragile than is desirable, because the end wall is diagonal. The present invention overcomes this drawback, and provides a block with the effective interlock shown in U.S. Pat. No. 6,591,569, but without the end wall weakness. Moreover, the corner blocks of the present invention present flatter surfaces, and therefore they stack more effectively for shipping.  
       SUMMARY OF THE INVENTION  
       [0006]     In a broad aspect, then, the present invention relates to a construction block for use in constructing walls, said block including a front panel, a rear panel, and at least one web connecting said front and rear panels, each of said front and rear panels being rectangular and having a top edge surface, a bottom edge surface, and right and left edge surfaces, said at least one web having top and bottom surfaces co-extensive with the top and bottom surfaces of said front and rear panels thereby to define a top surface of said block, and a bottom surface of said rock, said top surface of said block being provided with a shallow rectangular ridge along its length, flanked by longitudinally extending outer support surfaces, the lower surface of said block having a shallow rectangular channel formed therein along its length, flanked by longitudinally extending flat outer foot portions corresponding in width to said outer support surfaces; the right and left edge surfaces of said front and rear panels being profiled to interfit with one another, whereby the right front edge surface and the left rear edge surface each have a first profile, and the left front edge surface and the right rear edge surface each have a second profile, the first and second profiles being complementary to permit blocks to interfit end to end.  
         [0007]     In another broad aspect, then, the present invention relates to a construction block for use in constructing walls, said block including a front panel, a rear panel, and two transverse end webs connecting said front and rear panels, each of said front and rear panels being rectangular and having a top edge surface, a bottom edge surface, and right and left edge surfaces, said webs having top and bottom surfaces co-extensive with the top and bottom surfaces of said front and rear panels thereby to define a top surface of said block, and a bottom surface of said rock, said top surface of said block being provided with a shallow rectangular ridge along its length, flanked by longitudinally extending outer support surfaces, the lower surface of said block having a shallow rectangular channel formed therein along its length, flanked by longitudinally extending flat outer foot portions corresponding in width to said outer support surfaces; the end webs being profiled to interfit with one another, whereby the right front edge surface of one end web and the left rear edge surface of the other end web each have a first profile, and the left front edge surface of said one end web and the right rear edge surface of said other web each have a second profile, the first and second profiles being complementary to permit blocks to interfit end to end.  
         [0008]     The front and rear panels are preferably thickened toward the interior of said block at their right and left ends.  
         [0009]     The first profile may be a concave vertical groove, and said second profile is a convex vertical ridge.  
         [0010]     The concave vertical groove is preferably formed on the inner corner of a said edge surface.  
         [0011]     The convex vertical ridge is preferably formed on the inner corner of a said edge surface.  
         [0012]     two said webs may be provided, with a generally rectangular hollow core formed between them.  
         [0013]     The upper surface of said webs may be provided with a channel therein. The channel in the upper surface of said web will be large enough to accommodate reinforcing materials. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a perspective view of a stretcher block of the first embodiment of the present invention.  
         [0015]      FIGS. 2 and 3  are end views of the block of  FIG. 1 .  
         [0016]      FIGS. 4 and 5  are front and rear views of the block of  FIG. 1 ,  
         [0017]      FIGS. 6 and 7  are top and bottom views of the block of  FIG. 1 .  
         [0018]      FIG. 8  is a perspective view of a sash block of the first embodiment of the present invention.  
         [0019]      FIGS. 9 and 10  are end views of the block of  FIG. 8 .  
         [0020]      FIGS. 11 and 12  are front and rear views of the block of  FIG. 8 .  
         [0021]      FIGS. 13 and 14  are top and bottom view of the block of  FIG. 8 .  
         [0022]      FIG. 15  is a perspective view of a right corner block of the first embodiment of the present invention.  
         [0023]      FIGS. 16 and 17  are end views of the block of  FIG. 15 .  
         [0024]      FIGS. 18 and 19  are front and rear views of the block of  FIG. 15 .  
         [0025]      FIGS. 20 and 21  are top and bottom views of the block of  FIG. 15 .  
         [0026]      FIG. 22  is a perspective view of a left corner block of the first embodiment of the present invention.  
         [0027]      FIGS. 23 and 24  are end views of the block of  FIG. 22 .  
         [0028]      FIGS. 25 and 26  are front and rear views of the block of  FIG. 22 .  
         [0029]      FIGS. 27 and 28  are top and bottom views of the block of  FIG. 22 .  
         [0030]      FIG. 29  is a perspective view of a half sash block of the first embodiment of the present invention.  
         [0031]      FIGS. 30 and 31  are end views of the block of  FIG. 29 .  
         [0032]      FIGS. 32 and 33  are front and rear views of the block of  FIG. 29 .  
         [0033]      FIGS. 34 and 35  are top and bottom views of the block of  FIG. 29 .  
         [0034]      FIG. 36  is a perspective view of a half stretcher block of the first embodiment of the present invention.  
         [0035]      FIGS. 37 and 38  are end views of the block of  FIG. 36 .  
         [0036]      FIGS. 39 and 40  are front and rear views of the block of  FIG. 36 .  
         [0037]      FIGS. 41 and 42  are top and bottom views of the block of  FIG. 36 .  
         [0038]      FIG. 43  is a generic end view of a block of the second embodiment of the present invention.  
         [0039]      FIG. 44  is a top view of a stretcher block of the second embodiment of the present invention.  
         [0040]      FIG. 45  is a top view of a sash block of the second embodiment of the present invention.  
         [0041]      FIG. 46  is a top view of a half sash block of the second embodiment of the present invention.  
         [0042]      FIG. 47  is a top view of a half stretcher block of the second embodiment of the present invention.  
         [0043]      FIG. 48  is a top view of a right corner block of the second embodiment of the present invention.  
         [0044]      FIG. 49  is a top view of a left corner block of the second embodiment of the present invention.  
         [0045]      FIG. 50  is a plan view of two courses of blocks according to the second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]     Referring now to FIGS.  1  to  42  in general, in which the first embodiment of the present invention is illustrated by providing views of all of the blocks that may be desirable in a construction project, and in particular to FIGS.  1  to  7 , in which a stretcher block is shown, it will be seen that the basic block  1  of the present invention is generally rectangular. Rectangular front  2  and rear  3  walls are provided. The front and rear walls are connected by end webs  4 ,  5  and central web  6 . As can best be seen in  FIGS. 2 and 3 , the end  4 ,  5  and central webs are generally rectangular and are offset vertically from the front  2  and rear  3  panels. This forms a shallow rectangular channel  7  at the lower extremity of the block, flanked by feet  71  (see  FIG. 2 ).  
         [0047]     Moreover, the inner edge  8  of the front  2  and rear  3  panels also extends upwardly to the same vertical level as the webs. This feature permits the blocks to interlock vertically when stacked in courses, and the upwardly extending edge  8  of the front and rear panels prevents concrete from oozing out from between courses of blocks when the finished wall structure is filled.  
         [0048]     Generally semi-circular cut-outs  9  are formed in the top edges of each of the webs  4 ,  5 ,  6 . The purpose of the cut-outs is three-fold. They provide a horizontal channel in which re-bar may be laid before concrete is poured. They provide channels that concrete may flow through when poured, to ensure that the entire wall structure is filled. And lastly, they provide channels the concrete can harden in, so that adjacent blocks in a course are rigidly locked together.  
         [0049]     As can been seen most clearly in  FIGS. 1, 6 , and  7  the ends  4 ,  5 , of the blocks  1  are profiled to interfit with one another. At each end the web  4 ,  5  is inclined slightly, by 5°-10° from perpendicular to the front and rear walls. Moreover, where the end webs  4 ,  5  meet the front and rear walls, they curve with either a convex  10  or concave  12  portion, such that when the blocks are laid end to end, the flange  12  created adjacent the concave curve  11  will rest into the groove  13  created adjacent the convex curve  10 . A bead of caulking or construction adhesive may be applied to the grooves and flanges when courses of blocks are being laid, to assist in preventing water from penetrating between blocks.  
         [0050]     It will be observed that because the webs  4 ,  5 ,  6  are only angled slightly (about 5°-10°) and are fairly thick (about 2-3 cm) a perpendicular line Y (see  FIG. 7 ) from the front  2  to the rear  3  panel of the block will be contained entirely in the concrete of a web. Therefore, should the block encounter compressive forces on its exterior surfaces before being filled with concrete, these will be smoothly transmitted through the webs, rather than acting only as shearing forces on the webs.  
         [0051]     The block fully illustrated in  FIGS. 8-14  is known as a sash block  14 . It is essentially a stretcher block with one flat end, designed to finish a wall edge, for instance at a wall or window opening. A half sash block is shown in FIGS.  29  to  35 , and is used in combination with a sash block to complete alternate courses of blocks, to yield a flat wall end surface made up of vertically aligned flat surfaces  14  of sash and half-sash blocks.  
         [0052]     A half stretcher block, similar to a stretcher block, but of half the length and therefore missing middle web  6  is shown in FIGS.  36  to  42 .  
         [0053]     Right  15  and left  16  corner blocks respectively are illustrated in FIGS.  15  to  21  and  22  to  28 . Each corner block resembles a sash block in that it has one inclined end web  17  and a flat end  18  opposite. However, on the rear panel adjacent the flat end  18 , is formed a channel  19  profiled to fit the end of a stretcher block. In the case of a right corner block, the channel is inclined inwardly toward the flat end  18 , and in the case of a left corner block, the channel is inclined inwardly away from the flat end  18 .  
         [0054]     Directly above the channel  19  at the end of the corner blocks  15 ,  16 , channels  81  are formed in the inner edge of the front and rear panels of the corner blocks. Channels  81  accommodate feet  71  formed by the bottom edge of the front and real walls  2 ,  3 .  
         [0055]     FIGS.  43  to  50  illustrate an alternate embodiment of the present invention which, although outwardly dissimilar, is fully compatible, and stackable with, the embodiment illustrated in FIGS.  1  to  42 .  
         [0056]     In the alternate embodiment of the block of the present invention, as illustrated in  FIG. 43 , from the end perspective, the block  20  is substantially the same as that illustrated in FIGS.  1  to  42 . The upper surface  21  of the block has a raised central portion  22  profiled to interfit with a channel  24  formed in the lower surface  25  of the block. The profile of the upper surface  21  is defined by a flat raised portion  22  that is about ¼ inch to 1 inch high, flanked by flat portion  26  about ½ to 1½ inches wide. Similar flat foot portions  27  are formed in the lowermost surface of the block.  
         [0057]     The webs  28  of the block have semi-circular cut-outs  29  formed therein, for re-bar placement and to facilitate concrete flow.  
         [0058]     Referring to FIGS.  44  to  49 , wherein the various component blocks of the second embodiment are illustrated, it will be observed that each block has front  30  and rear  31  surfaces which terminate in laterally enlarged ends  32 . Each end  32  of a front or rear panel has a laterally facing flat portion  33  adjacent the front or rear surface, and a vertically extending convex  34 , or concave  35 , interfit element on its inner edge. It will be observed that the overall length of the front  30  and rear  31  panels is identical. At each end, however, the flat portion  33  adjacent the concave interfit element will be aligned with the outer edge of the convex interfit element  34  on the opposite front, or rear panel. Therefore, when the blocks are laid in a course, the course will run straight. It will also be observed, in this regard, that each front panel  30  has a concave element  35  at one end, and a convex element  34  at the other end, as does each rear panel  31 , but with the concave  35  and convex  34  elements reversed in position.  
         [0059]     The enlarged portions  32  at each end of the front and rear panels provide enhanced stability and strength of the completed walls. As can be seen in  FIG. 50 , when a first course of blocks including for exemplary purposes a block B 1  has a second course of blocks including a block B 2  laid on top of it, the ends of the blocks are staggered so that the end of block B 1  is located below the hollow central core of block B 2 . Enlarged portion  32  of block B 1  will not therefore be aligned with the inner wall of block B 2 . This will be the case for all blocks in all courses. When the hollow cores of the blocks are filled with concrete, then, the enlarged portions  32  will act as mechanical anchors in the concrete as it sets, to provide enhanced strength to the wall when the concrete hardens. The enlarged portions  32  also ensure that even if the bond between the blocks and poured concrete should fail for any reason, adjacent blocks, either vertically or horizontally adjacent, could not pull apart.  
         [0060]     Corner blocks of the alternate embodiment of the invention, as shown in  FIG. 48 , have a flat end  36  that together with the front face  37  of the block, will define the corner of a wall being constructed. On the rear face  38 , notch  39  with a convex inside edge  40  and a concave groove  41  are formed convex edge  40  and concave groove  41  are spaced apart by a distance corresponding to the spacing between convex  34  and concave  35  interfit elements at the end of the front and rear panels of stretcher block  20 . Accordingly, a stretcher block can be abutted against the rear face of the corner block, with interfit elements  34  and  35  accommodated by concave groove  41  and convex edge  40  respectively.  
         [0061]     The raised portion  22  on the top surface of the corner block of the second embodiment, directly above groove  41  and notch  39  with edge  40  is channelled to accept the foot portion  27  of a block laid on it perpendicularly. It will be noted that foot portion  27  may be found under flat ends  36  of the corner blocks, and in that case, appropriate corresponding channels will be formed in the upper surface to accommodate same.

Summary:
A construction block includes rectangular front and rear panels and at least one web connecting the front and rear panels. Each of the front and rear panels has top, bottom, and right and left edge surfaces. At least one web having top and bottom surfaces co-extensive with the top and bottom of the front and rear panels is provided to define top and bottom surfaces of the block. The top surface of the block has a shallow rectangular ridge along its length, flanked by outer support surfaces. The lower surface of the block has a shallow rectangular channel along its length, flanked by flat outer feet corresponding to the outer support surfaces. The right and left edge surfaces of the front and rear panels are profiled to interfit with one another.