Abstract:
A method for roughing surfaces and edges of concrete casted blocks, comprising a block support surface having a plurality of surface sections. A first of the surface sections has a rear end thereof above an adjacent front end of a second of the surface sections to create a ledge for projecting a leading edge portion of concrete blocks conveyed over the first surface section. A first roughing device has a plurality of impacting elements thereon for roughing concrete blocks. The first roughing device is disposed generally above the rear end of the first surface section for abrading a projecting leading edge portion of each concrete block as they are conveyed over the rear end. A conveyor displaces concrete blocks over the first and second surface sections, the blocks being tilted when reaching a predetermined position over the ledge to avoid being abraded by the roughing device.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a divisional of application Ser. No. 09/911,121, filed Jul. 24, 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to casted concrete block manufacturing and, more particularly, to a method for roughing blocks to give them a worn or rough appearance.  
         BACKGROUND OF THE INVENTION  
         [0003]    The concrete block casting industry is well developed and is highly automated in its process operations for manufacturing conventional rectangular concrete blocks and the like. The casted blocks have a geometrically uniform rectangular prism configuration in which the surfaces thereof are substantially planar with adjacent surfaces delimited by sharp edges.  
           [0004]    It has been known to treat the concrete blocks in order to get a more natural rough look. As authentic stone blocks are known to have rounded edges and irregular shaped surfaces, systems have been provided in order to produce such effect on casted concrete blocks. However, the equipment used in order to treat these blocks has been incompatible with the fully automated handling equipment used in the other operations of the concrete block producing process. Substantial amount of manual labor and high costs are inherent with the presently used block roughing systems.  
           [0005]    For instance, a known method consists in disposing the casted blocks in large tumbling drums. These tumbling drums are rotated about their longitudinal axis in order for the concrete blocks to tumble therein and to collide in order to get damaged. This method, although producing a generally satisfying look, entails substantial costs due to unrepairable damages to concrete blocks. Some blocks are damaged to a point where they may no longer be used and are thus thrown away or recycled. Also, some concrete block patterns may contain blocks of different sizes and these must be sorted and assembled, which is very time consuming. Also, if a particular one of the blocks in pattern is destroyed more than other blocks, then often the other blocks are no longer useful as a ratio of blocks must be kept. By its nature, the tumbling drum requires frequent repairs. Furthermore, the personnel used for these purposes must deal with a noisy environment due to the tumbling action, and injuries are frequent due to the hazardous operations and handling required thereby. It is difficult to maintain a stable labour force for this work.  
           [0006]    U.S. Pat. No. 5,133,915, issued on Jul. 28, 1992 to Metten et al., discloses a surface upon which a plurality of concrete blocks are disposed in a spaced apart relationship. A roller brush translates over the surface of concrete blocks in a reciprocating manner, thereby stripping and roughing the surface of the concrete blocks. Although this method provides substantial advantages over the tumbling drum method described above, it requires that the concrete blocks are spaced apart in order for the sharp edges thereof to be treated. Otherwise, only the top surface would be abraded. Furthermore, the brush type roller provides a relatively uniform abrasion of the concrete blocks, which is not a desired result for use with paving blocks. Finally, as the concrete blocks are spaced apart, the brush can only strike them at a certain velocity in order not to displace them. If they are displaced, they may end up in abutment with one another, whereby only the top surfaces will be abraded, leaving the sharp edges of the block intact. These blocks are usually treated before the concrete is cured. This patent could not provide the desired result of producing an irregular roughened appearance to concrete blocks.  
         SUMMARY OF THE INVENTION  
         [0007]    It is a feature of the present invention to provide a concrete block roughing apparatus and method which substantially overcomes the disadvantages of the above mentioned prior art.  
           [0008]    According to a broad aspect of the present invention, there is provided a method for roughing portions of solid concrete casted blocks. The method comprises conveying a plurality of concrete casted blocks disposed in side-by-side aligned relationship over a block support surface having a straight front edge and a rear end edge disposed parallel to one another. At least a section of the support surface is inclined to create a ledge at the rear end edge and extending across a travel path of the plurality of concrete casted blocks in side-by-side relationship for projecting a leading edge portion of the concrete blocks conveyed over the ledge. A roughing device is provided with at least a plurality of impacting elements thereon and is disposed a predetermined distance above the block support surface forwardly of the rear end edge. The leading edge portions of the, concrete blocks disposed in side-by-side relationship are impacted by the roughing device as they are projected over the ledge by the conveying means. The blocks are tilted when reaching a predetermined position over the ledge. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    A preferred embodiment of the present invention as illustrated by examples thereof will now be described with reference to the accompanying drawings in which:  
         [0010]    [0010]FIG. 1 is a perspective view of an apparatus for roughing concrete blocks in accordance with the present invention;  
         [0011]    [0011]FIG. 2 is an enlarged elevational view of slanted support panels and a roughing tool in accordance with the present invention;  
         [0012]    [0012]FIG. 3 is an enlarged perspective view of an embodiment of the roughing tool;  
         [0013]    [0013]FIG. 4 is a simplified schematic top plan view of a series of apparatuses for roughing concrete blocks;  
         [0014]    [0014]FIG. 5 is an enlarged side elevational view of another embodiment of the apparatus for roughing concrete blocks of the present invention; and  
         [0015]    [0015]FIG. 6 is an enlarged side elevational view of still another embodiment of the apparatus for roughing concrete blocks of the present invention. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0016]    According to the drawings and, more particularly to FIG. 1, an apparatus for roughing concrete blocks (i.e bricks, paving stones, wall retaining blocks, masonry stones) is generally shown at  10 . The apparatus  10  comprises a table  11  having a top surface  12 , a front end  13 , a rear end  14  and lateral sides  15  and  16 . The top surface  12  is defined by rectangular panels  17 ,  18 ,  19  and  20 . It is observed that the rectangular panel  17  is at the front end  13  of the table  11 , whereas the rectangular panel  20  is at the rear end  14  thereof.  
         [0017]    The rectangular panels  17 ,  18  and  19  are each secured to the table  11  in a slanted or inclined position with respect to the horizontal, such that each of the rectangular panels  17  and  18  has its front side edge lower than its rear side edge. Rectangular panel  19  is flat on the table for reasons which will be described later. Consequently, as seen in FIG. 1, a rear side edge  17 R of the rectangular panel  17  is vertically offset with respect to adjacent front side edge  18 F of the rectangular panel  18 , such as to be above it to create a ledge L. It is pointed out that there is a similar relation between the front side and rear side edges of the rectangular panels  18  and  19 . It is also pointed out that the rectangular panel  20  is substantially horizontal and in a co-planar relationship with the rectangular panel  19 . Its rear side edge  20 R represents the rear end  14  of the table  11 . Also, the present invention is not restricted to four rectangular panels as fewer or more rectangular panels could form the table  11 . Furthermore, the successive rectangular panels being cascaded could each have been in a horizontal position rather than in a slanted position, with a decrease in vertical positioning from the front end  14  of the table  11  to the rear end  15  thereof, such as to, again, have a cascading relation between the rectangular panels.  
         [0018]    Support posts  25 A and  25 B project upwardly from the lateral sides  15  and  16 , respectively, of the table  11  on opposed sides of the junction of the rectangular panels  17  and  18 . Similar support posts  26 A and  26 B, and  27 A and  27 B are upwardly extending at opposed sides of the junctions of the rectangular panels  18  and  19 , and of the rectangular panels  19  and  20 , respectively.  
         [0019]    Each of the support posts has at a top end thereof a throughbore having a journal bearing therein (not shown). The support posts  25 A and  25 B support a roughing tool  30  through their journal bearings. The roughing tool  30  is comprised of a pair of disks  31 A and  31 B removably linked by support bars  32 . A drive shaft  33 A is secured to the disk  31 A, whereas the other disk  31 B is connected to an idle and free to rotate shaft (not shown) journaled at the top end of the support post  25 A. A plurality of chain link sections  34  are secured to the support bars  32 , and are comprised of at least two interconnected loop chain links. The support bars  32  extend through an end loop of each chain link section  34 . By rotating the roughing tool  30  on its longitudinal axis, the chain link sections  34  will impact predetermined areas of concrete blocks C disposed on the table  11 , as will be described later. The roughing tool  30  is rotated by a motor M 1  connected to the drive shaft  33 A by a belt B 1  and pulley P 1  assembly. The motor M 1  may consist a variable speed electric motor.  
         [0020]    Generally identical roughing tools  40  and  50  are journaled between the support posts  26 A and  26 B, and  27 A and  27 B, respectively. The roughing tools  40  and  50  comprise the same elements as the roughing tool  30 . Therefore, the roughing tools  40  and  50  will not be described. However, when referring to FIG. 1, like elements will be related by having like last digits. For instance, the disks  31 A and  31 B for the roughing tool  30  are generally identical to the disks  41 A and  41 B of the roughing tool  40 . Similarly, the disks  51 A and  51 B of the roughing tool  50  are generally identical to the disks  31 A of the  31 B of the roughing tool  30 . However, for clarity purposes, the motors and belt/pulley assemblies driving the roughing tools  40  and  50  are not shown.  
         [0021]    The slanted or inclined positioning of the rectangular panels  17  and  18 , whereby they are cascaded, allows for given portions of the concrete blocks C disposed on the top surface  12  of the table  11  to be exposed to the chain link sections  34  and  44  of the roughing tools  30  and  40 , respectively, during their travel over the panels and specifically over the ledges. As best seen in FIG. 2, the configuration of the rectangular panel  17  with respect to panel  18  allows for only an edge C′ of a concrete block C to be exposed for being impacted by the chain link sections  34  as it is conveyed by the conveyor bars  65  over the ledge L. As a bottom face of the concrete block C is projected over the ledge L, the block C will tilt down and fall on the rectangular panel  18 , and its top surface C″ will avoid the chain link sections  34 . As the concrete block C further advances on the table  11 , contact with the chain link sections  34  is still avoided until it is projected again on the next ledge. The roughing tools  30 ,  40  and  50  may be positioned strategically with respect to the table  11  in order for predetermined portions of the concrete blocks C to be abraded.  
         [0022]    Consequently, the slanted configuration of the rectangular panels  17  and  18  allows for only the exposed edge portions of the concrete blocks C to be roughened. In the embodiment shown, three roughing tools are provided in order to treat the concrete blocks C disposed thereon for various effects. The roughing tool  30  is positioned to strike the exposed edges C′ of the concrete blocks C such as to do a rough treating thereof and remove bigger chunks of material. The roughing tool  40  is positioned such as to treat the edges of the blocks C to a smoother finishing. As can be seen, rectangular panel  19  is flat and the roughing tool  50  is positioned to abrade the top surface C″ of the blocks C.  
         [0023]    The roughing tools  30 ,  40  and  50  are driven by a variable speed motor (not shown) and may thus be rotated to various speeds in order to impact the concrete blocks C at various forces. They can also be independently driven. As seen in FIG. 3, a bolt B and nuts N have been added to an end chain link of a chain link section  34  such as to provide a random pattern on the concrete blocks C upon same being struck.  
         [0024]    Returning now to FIG. 1, the apparatus  10  is provided with a conveyor  60  to displace the concrete blocks C over the panels  17 ,  18 ,  19  and  20 . The conveyor  60  comprises a pair of chain loops  61 A and  61 B adjacent the lateral sides  15  and  16 , respectively, of the table  11 . The chain loop  61 A is operatingly held about a pair of sprockets  62 F and  62 R, with the sprocket  62 R being driven by a motor M 2  and a belt B 2  and pulley P 2  assembly. The chain loop  61 B is disposed about a sprocket  63 F and the driven sprocket  63 R, the latter being connected to an opposed end of an axle  64  upon which is secured the sprocket  62 R. The chain loops  61 A and  61 B are linked by a plurality of bars  65  which are equidistantly spaced. The bars  65  come in contact with the concrete blocks C disposed on the top surface  12  of the table  11  such as to displace the concrete blocks C from the front end  13  to the rear end  14  thereof. It is noted that the motor M 2  may be of various speeds in order to provide various velocities to the blocks moving forward.  
         [0025]    As shown in the schematic representation of FIG. 4, a plurality of apparatuses for roughing concrete blocks or tables in accordance with the present invention may be provided in series in order to treat the various edge surfaces and top surfaces of the concrete blocks C. Concrete blocks C are initially loaded onto apparatus  10 A such as to have first lateral side edges thereof treated by roughing tools  30 A (rougher edge finish) and  40 A (smoother edge finish). For clarity purposes, elements of an apparatus have been affixed a like letter (for instance, roughing tool  30 A of apparatus  10 A). The concrete blocks C are then transferred to a transfer table  10 A, where a push bar  101 A will load the concrete blocks C to apparatus  10 B. It is pointed out that the front side edges of the concrete blocks C will now be treated as a consequence of the apparatus  10 B being perpendicular to the apparatus  10 A.  
         [0026]    The concrete blocks C will then move onward to the apparatuses  10 C and  10 D through the transfer tables  100 B and  100 C, respectively, so as to be treated on all side edges. A third roughing tool  50 D is provided on the apparatus  10 D to treat the top surface of the concrete blocks C. This operation only requires to be achieved once as all side edges of the concrete blocks C share the same top surface. The concrete blocks can be loaded on to a stack of concrete blocks (not shown) by transfer table  100 D at an end of the series of apparatuses. It is observed that a plurality of concrete blocks C are treated at a same time on the series of apparatuses, whereby this configuration advantageously allows for a continuous output of treated concrete blocks.  
         [0027]    The panels forming the block support surface of the apparatuses may be solid. It has also been thought to provide a grid surface, as shown at G for one of the panels of apparatus  10 B in FIG. 4, so that concrete particles resulting from the concrete blocks being treated fall through the grid surface G to the floor, thereby not accumulating on the top surface of the panels.  
         [0028]    Referring to FIG. 5, a further embodiment of the apparatus  10  is shown, wherein the concrete blocks C will be abraded from a roughing tool  60 , similar to the roughing tools  30 ,  40  and  50  described above, but disposed underneath the top surface  12 , herein shown below rectangular panels  17  and  18 . The rectangular panels  17  and  18  in this embodiment are shown further spread apart by a gap G 2 , as well as being offset by ledge L, to allow for the bottom trailing edges of concrete blocks C to drop in the gap G 2  to be exposed to the abrading chain link sections  64  of the roughing tool  60  to be abraded thereby. Guides (not shown) are provided such that the bars  65  and the chain loops  61 A and  61 B avoid the chain link sections  64  of the roughing tool  60  when moving across the gap G 2 .  
         [0029]    Referring to FIG. 6, the roughing tool  60  is depicted once more underneath the top surface  12  of the roughing apparatus  10 , yet the rectangular panels  17  and  18  are not offset by the ledge L, whereby the concrete blocks driven across the gap G will have their, bottom trailing surfaces exposed to be abraded by the chain link sections  64 ′ of the roughing tool  60 ′.  
         [0030]    Having the roughing tool  60  below the top surface  12  ensures that the chips or the dust resulting from the abrading action on the concrete blocks C will not accumulate on the top surface  12  of the apparatus  10 . The roughing tool below the top surface  12  are used in combination with roughing tools disposed above the top surface  12  of the apparatus  10 , as described above, whereby two opposed sides and edges of the concrete blocks C are abraded on the same apparatus.  
         [0031]    It is within the ambit of the present invention to cover any obvious modifications of the embodiments described herein, provided such modifications fall within the scope of the appended claims.