Abstract:
A device for removing concrete debris from passages within modular blocks is disclosed. The device includes nozzles mounted to a plate at locations corresponding to the passages on the modular blocks. An actuator is secured to the block molding machine, supports the plate, and moves the plate from a retracted position to an extended position in close proximity to the conveyor. The nozzles are operatively connected to a source of compressed air and are arranged to enter within the passages of the modular block when the plate moves to the extended position. A control system directs operation of the device such that when a modular block reaches a predetermined location on the conveyor, the actuator moves the mounting plate to the extended position causing the nozzles to enter within the passages of the modular block and emit jets of compressed air to remove concrete debris from within the passages.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     “Not Applicable” 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     “Not Applicable” 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK 
     “Not Applicable” 
     FIELD OF THE INVENTION  
     This invention relates generally to the manufacture of concrete blocks. More specifically, this invention relates to a device for removing debris from passages in manufactured modular blocks, such as wallstones. 
     BACKGROUND OF THE INVENTION 
     Modern, high speed, automated concrete block plants and concrete paver plants make use of concrete block molds that are open at the top and bottom. These molds are mounted in machines which cyclically station a pallet below the mold to close the bottom of the mold, deliver dry cast concrete into the mold through the open top of the mold, densify and compact the concrete by a combination of vibration and pressure, and strip the uncured blocks from the mold by a relative vertical movement of the mold and the pallet. Once the blocks are stripped from the mold they are protected until they are sufficiently hardened to permit handling without damage. The concrete blocks thus hardened are cured in a curing yard to permit complete moisturization for at least twenty-one days. 
     For efficient high-volume production, concrete block molds are typically configured to produce multiple blocks simultaneously. A concrete block mold generally comprises side walls and end walls that define the periphery of a mold cavity. Within this mold cavity, division plates may be used to sub-divide the mold cavity into a plurality of block-forming cavities. Further, movable side walls may be used to form the side faces of the block-forming cavity. The division plates are generally rectangular-shaped plates attached to the side walls of the mold. Further, the side walls of the block cavity and the division plates may be covered with replaceable mold face linings to protect the mold components from abrasive wear. 
     Concrete blocks fabricated by the automated processes described above are often used in the construction of vertical walls, such as sitting walls, or set-back retaining walls for securing earth embankments against sliding and slumping. The blocks, often referred to as wallstones are stacked on each other and located in rows to form a wall. The wall structure can have a variety of shapes, such as linear, concave, and convex curved, serpentine and circular to conform to the landscape utilization. Each wallstone may have one or more attractive and decorative faces. The decorative faces can be smooth, serrated, horizontally grooved, vertically grooved, diagonally grooved, checkerboard or have an aggregate appearance. The front face of the block can be broken apart concrete or broken irregular pattern. The wallstone may be of any desired color including gray or earth tones and the like. 
     Each wallstone may have a generally flat top and bottom surface so that the rows of wallstones can be stacked or superimposed on top of each other. The adjacent rows of blocks may be connected together with rods or pins. Each block has one or more passages extending from the top surface to the bottom surface to accommodate the rods or pins. Rows of wallstones overlap each other so that each wallstone is pinned to adjacent wallstones located in adjacent courses of wallstone above and below. Multiple passages may be provided to the wallstones to add versatility so that each wallstone may be used in the construction of a vertical wall or a set-back wall. 
     For example, the wallstone may be fabricated to be versatile by providing six passages, four to be utilized for the construction of a set-back wall and two to be utilized for the construction of a vertical wall. To construct a set-back wall, after a first layer of wallstone is set and leveled in all directions to create a base, a subsequent course is added such that the two front passages of the subsequent layer wallstones are aligned above a pocket (also referred to as an “offset pocket”) located in the wallstones in the course below, to create a slight offset. After the wallstones are set and visually aligned, pins are dropped in these two holes and into the pockets in the wallstones of the base layer. This process is repeated as subsequent courses are added above previous courses to construct a set-back wall. In this manner, the wallstones become interlocked together, adding strength and integrity to the overall wall structure. To construct a vertical wall, the two passages located in the pocket of the wallstones of the subsequent course are aligned above the pocket of the wallstones in the previous course, and pins are dropped in these two holes and into the pocket in the wallstones of the previous course. 
     A common drawback is that during fabrication of the wallstones, debris created during the fabrication process can become lodged in the passages. If not removed quickly, the debris will cure within the passages and create obstructions therein, thus preventing use of the interlocking feature of the wallstones. Currently, the method for cleaning the passages of such debris involves manually inserting a dowel into each of these passages after the wallstone is stripped from the mold within the production environment and which adds to the overall cost and increases safety concerns. Such manual debris removal from the passages has other disadvantages. It is a delicate operation requiring a certain amount of dexterity to avoid damaging the passages of uncured wallstones. Also, the current manual cleaning requires added labor expressly dedicated to this particular task to keep pace with the high volume of wallstone being produced by the automated process. Thus, the debris removal device of the present invention offers significant advantages over the current manual cleaning described above. The debris removal device of the present invention is operative to direct a flow of pressurized fluid, such as air through a plurality of outlets and through the passages of wallstones as the wall stones are conveyed after being stripped from the mold. The device of the present invention is automated and may be integrated into the concrete block manufacturing process, thus eliminating the need for increased labor. Also, the device of the present invention can remove debris from multiple passages simultaneously to keep pace with the rate of automated production. Also, the device will substantially reduce the potential for damage to the wallstone passages. 
     SUMMARY OF THE INVENTION 
     A device for removing concrete debris from passages within modular blocks is disclosed. The device includes nozzles mounted to a plate at locations corresponding to the passages on the modular blocks. An actuator is secured to the block molding machine, supports the plate, and moves the plate from a retracted position to an extended position in close proximity to the conveyor. The nozzles are operatively connected to a source of compressed air and are arranged to enter within the passages of the modular block when the plate moves to the extended position. A control system directs operation of the device such that when a modular block reaches a predetermined location on the conveyor, the actuator moves the mounting plate to the extended position causing the nozzles to enter within the passages of the modular block and emit jets of compressed air to remove concrete debris from within the passages. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of an exemplary prior art mold for forming concrete blocks; 
         FIG. 2  is a side view showing the arrangement of the prior art mold in  FIG. 1  in a prior art concrete block molding machine; 
         FIG. 3  is a prior art concrete molding machine showing the mold after being filled with a known concrete block mix; 
         FIG. 4  is a prior art concrete molding machine illustrating the head shoe assembly compressing the concrete mix in the mold; 
         FIG. 5  is a prior art concrete molding machine illustrating the compressed concrete block being ejected by the head shoe assembly moving downward as the movable plate that forms the bottom of the mold moves downward; 
         FIG. 6  is a perspective view of a first concrete block such as a wallstone of a prior art modular block system; 
         FIG. 7  is a top view of the first concrete block or wallstone shown in  FIG. 6 ; 
         FIG. 8  is a top view of a mold box having a first, second, third, and fourth blocks and pavers formed therein; 
         FIG. 9  is a perspective view of a structure constructed with the prior art modular wallstones of  FIG. 8 ; 
         FIG. 10  is an elevational view of the device for removing debris from passages of concrete modular blocks of the present invention shown attached to the framework of a concrete block molding machine, illustrating the device in the retracted position; 
         FIG. 10A  is a detail view of an encircled portion of  FIG. 10  illustrating movement of the device of the present invention between a retracted position and an extended position; 
         FIG. 11  is an elevational view of the device of the present invention illustrating the device in the extended position; 
         FIG. 12  is a top view of a portion of the concrete molding machine of the prior art illustrating a prior art wallstones being conveyed over the device of the present invention; 
         FIG. 13  is an elevational view of the device of the present invention shown, the device shown affixed to the framework of a prior art concrete molding machine; 
         FIG. 14  is a perspective view showing the top of the device of the present invention; and, 
         FIG. 15  is a perspective view showing the bottom of the of the device of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now in greater detail to the drawings in which like numerals represent like components throughout the several views, the process for molding a concrete block such as a wallstone is described. Referring to  FIG. 1 , there is shown an end view of a prior art mold assembly  14  for molding a concrete block, such as a wallstone is shown. The prior art mold assembly  14  may include two openings  18  and  22  that are surrounded by side walls  26 . Note that openings  18  and  22  preferably extend the full depth of the mold assembly  14 .  FIG. 2  shows a side view showing various components in a prior art concrete block molding machine  30 . The prior art mold assembly  14  is arranged to be bolted to the concrete block molding machine  30 . Examples of concrete block molding machines for which the prior art mold assembly  14  include models manufactured by Columbia and Besser. In one embodiment, installation of the mold assembly  14  in the concrete block molding machine  30  further includes installation of a core bar assembly, which is known to those skilled in the art, which is positioned within the mold cavity to create through holes or passages within the formed block in accordance with design requirements of a particular block. The prior art mold assembly  14  is fixedly attached to the concrete block molding machine  30  so its position does not change with respect to the molding machine  30 . A top plunger  34  includes a head shoe assembly  38  that has two protruding portions  42  and  46  that have shapes corresponding to the openings  18  and  22  in the mold  14 , and are just slightly smaller to allow the protruding portions  42  and  46  of the shoe assembly to pass through the full depth of the mold  14  within the openings  18  and  22 . A movable plate  50  known in the art as a “pallet” forms the bottom of the mold  14 , and is raised and lowed by a bottom plunger  54 . The top plunger  34  and bottom plunger  54  are moved up and down with respect to mold  14  to form a manufactured wallstone, as discussed in more detail below. 
       FIG. 3  shows the concrete block molding machine  30  after the block mix has been poured into the mold  14 , as shown by the hatched portions  58  and  62  in the mold  14 . The movable plate  50  is moved by bottom plunger  54  to contact the bottom of the mold  14 . The block mix is then poured into the mold  14 , then screeded off even with the top of the mold  14 . Many concrete block molding machines have top hoppers that receive block mix from a belt-type conveyor, and have feed drawers that direct the block mix from the top hopper into the mold, then screed off the excess block mix to be even with the top of the mold. This process is well-known, and is therefore not discussed here in further detail. Once the block mix is in the mold, the top plunger  34  moves down the protruding portions  42  and  46  of the head shoe assembly  38  to contact the top of the block mix at  58  and  62 , as shown by the smaller arrow  64  in  FIG. 4 . Once contact is made, substantial pressure is applied to the block mix at  58  and  62  by the protruding portions  42  and  46  of the head shoe assembly  38  to compact or compress the block mix, as represented by the larger arrow  68  in  FIG. 4 . The compaction of the block mix under high compressive force evenly distributes the block mix in the mold, and also hardens the block mix so the block will retain its shape after being ejected from the mold after only a few seconds of compression in the mold. As shown in  FIG. 5 , after the block mix has been sufficiently compressed for a sufficient period of time, the top plunger  34  pushes the head shoe assembly  38  down at the same time the bottom plunger  54  is moving the movable plate  50  down, resulting in the blocks  58  and  62  being ejected from the mold  14 . At this point the top plunger  34  may move up to its original position shown in  FIG. 3 , the movable plate  50  with the blocks  58  and  62  is typically conveyed away from the concrete block molding machine  30 , and a new movable plate will be placed on the bottom plunger  34 , which will then move the movable plate to contact the bottom surface of the mold as shown in  FIG. 3 . At this point the cycle can repeat, forming and ejecting a block in a matter of seconds. A typical cycle time for a concrete block molding machine is 12-15 seconds, but may be significantly faster or slower depending on the features and age of the concrete block molding machine. 
     An example of a block made from the molding process described above is indicated at  70  in  FIG. 6 . The block  70 , shown in perspective view in  FIG. 6 , is a retaining wall block that uses a pin and groove design to assist in stabilizing a wall. The block  70  has the front face  74 , a back face  78 , a top  82 , a bottom  86 , a first side  90 , and a second side  94 . The faces  74  and  78 , the top  82 , the bottom  86 , and the sides  90  and  94  are used to form the block  70 . The block  70  may be a first block utilized in a modular block system which may be comprised of several differently shaped blocks, e.g., four differently shaped blocks. The top  82  has formed therein an indicator  88  to indicate which block in the modular block system this particular block is. In this case, the block  70  is referenced as being the “A” block in the modular block system. Other blocks (not shown) in the modular block system may include indicators such as “B”, “Y” or “X”. As can be appreciated, when constructing a structure using the modular block system, instructions may be included with the system to show where to place this particular block  70 . Also formed in the top  82  of the block  70  is a marking  98  that shows the name of the modular block system. 
     The top  82  has a pair of score lines or recesses  102  and  106  that are used to split the block  70  into two separate blocks. The score lines  102  and  106  allow the block  70  to be split into two blocks with the score lines  102  and  106  being centered on the wider or front face  74 . The top  82  also has a pair of offset pockets  110  and  114  formed therein. The offset pockets  110  and  114  are used to construct a retaining wall structure in a tiered formation with each tier being setback or offset from each other. The pockets  110  and  114  provide for a predetermined or preselected distance that each of the tiers will be setback. As best shown in  FIG. 7 , within each pocket  110  and  114  is a passage  116  that may extend the entire height of the block  70 . On each side of the pocket  110  is a pair of shallow grooves  118  and  122 . Within the groove  118  is a passage  126  and within the groove  122  is a passage  130 . The passages  126  and  130  may extend the entire height of the block  70 . The passages  116 ,  126  and  130  are adapted to receive rods or pins for use in constructing a landscaping structure. Further, on each side of the pocket  114  is another pair of grooves  134  and  138 . Again, within the groove  134  is a passage  142  and within the groove  138  is a passage  146 . The passages  142  and  146  may extend the entire height of the block  70 . The block  70  also may have an alignment groove  150  along the first side  90  centered on the pocket  114 . Although not shown, there is an alignment groove on the second side  94  centered with the pocket  110 . The alignment groove  150  is used to align or offset the blocks of the modular block system  10  when constructing a wall structure. 
     With reference now to  FIG. 7 , a top view of the block  70  is illustrated. The block  70  is shown to have the front face  74  being wider or longer than the back face  78 . This is due to the first side  90  being slanted back toward the back face  78 . Also, the second side  94  is not slanted at all, but is straight from the front face  74  to the back face  78 . The block  70  also has beveled corners  154 ,  158 ,  162  and  166 . The reason the corners  154 ,  158 ,  162  and  166  are beveled is to prevent the block  70  from being broken or chipped during manufacturing, transportation, storage, or handling. Although not shown in this particular illustration, the back face  78  also has a split face surface. The block  70  is also depicted having the indicator  88  and the marking  98  formed in the top  82 . The score lines  102  and  106  are parallel to the second side  94 . The score lines  102  and  106  only span a portion of the top  82 . Other blocks similar in design that are included in the modular block system are described more fully in U.S. Pat. No. 8,176,702, entitled “Modular Block System” the relevant portions of which are hereby incorporated by reference. 
       FIG. 8  shows a mold box  200  for forming the modular block system comprising the first block  70 , a second block  204 , a third block  208  and a fourth block  212  formed therein. The mold box  200  is generally rectangular in shape and may have dimension of 26 inches by 18½ inches. The first block  70  and the second block  204  are formed together at a junction or score line  216 . The blocks  70  and  204  may be split apart from each other. Also, the first block  70  may have the back face  78  formed by splitting a paver  220  at a junction or score line  224 . Splitting a paver  220  at a score line  224  forms the back face  78  of the first block  70 . Similarly, splitting a paver  221  at a score line  222  forms the back face of the second block  204 . The third block  208  and the fourth block  212  are initially formed together at a score line  228 . Once the third block  208  and the fourth block  212  are separated along the score line  228 , split faces are formed. The back face of the third block  208  is formed by splitting a paver  232  along a score line  235 . Finally, the fourth block  212  is completed by splitting a paver  236  along a score line  240 . The pavers  220 ,  221 ,  232 , and  236  may be used for other landscaping projects and do not need to be discarded. The first and second blocks  70 ,  204  are not connected to the third and fourth blocks,  208  and  212  during the manufacturing process, as there is a gap  244  therebetween. 
     As can be appreciated, the blocks  70 ,  204 ,  208  and  212  along with the pavers  220 ,  221 ,  232  and  236  of the present invention are formed in the mold box  200 . Generally, the process entails molding the blocks  70 ,  204 ,  208  and  212  and the pavers  220 ,  221 ,  232  and  236  by using a mixture of cement and water and other materials, as described above. The blocks  70 ,  204 ,  208  and  212  and the pavers  220 ,  221 ,  232  and  236  are fabricated by compressing and vibrating the mixture in the mold box  200  by the application of pressure to the mixture by use of a block molding machine as described above. It is also known to use a press head having a press plate for applying pressure to the mold box  200 . Further, the press plate may include structure that forms the shallow grooves, the indicators, and the markings in each of the blocks  70 ,  204 ,  208  and  212 . Also, an insert bar may be used to form the passages  116 ,  126 ,  130 ,  142 , and  146  and the offset pockets  110  and  114  in each of the blocks  70 ,  204 ,  208  and  212 . Once the blocks and pavers are formed they may be cured through any method known in the art. For example, curing may take the form of air curing for a number of days or steam curing, but normally one day is allowed or needed for cure. 
       FIG. 9  depicts how rods or pins  248  and  252  may be used with the modular block system. A structure  256  is constructed by forming a first course  260  that consists of an “A” block  264  and a “Y” block  268 . A second course  272  that includes a “B” block  276  is placed over the first course  260 . The pin  248  is inserted into the passage  280  to pass through the block  276  to be captured in the offset pocket  114  of the block  268 . In particular, if the pin  248  is six and a half inches long and the block  276  is six inches thick then about a half inch of the pin  248  will be lodged or captured in the pocket  114 . The pin  252  is inserted into the passage  284  to pass through the block  276  into the offset pocket (not shown) of the block  264 . The pocket is not visible or shown due to the block  276  covering the pocket. By using the pins  248  and  252  and the passages  280  and  284  and the offset pockets, the block  276  of the second course  272  is offset or setback a distance from the first course  260 . An example of the setback may be three quarters of an inch. 
     As discussed previously, debris created during the fabrication process can become lodged in the passages  116 ,  126 ,  130 ,  142  and  146 . It is not uncommon for debris to accumulate within these passages to a depth of two inches or greater. If not removed quickly, the debris will cure within the passages and create obstructions therein, thus preventing use of the pins  248  and  252  for creating an offset or setback of courses of the wallstones. Under the present invention, a device is provided for injecting air within the passages so that loose concrete particles within the passages can be flushed out so the passages are useable for the purposes mentioned above. 
     Referring now to  FIGS. 10 ,  12 , and  13 , the concrete block molding machine  30  includes a stationary support frame  288  for supporting a closed-loop conveyor system  290  ( FIG. 13 ) adapted for transporting loads such as a finished block  292  to a predetermined location for flushing loose concrete particles from within the passages  292   a  therein. It should be understood that the prior art concrete block molding machine is capable of molding a variety of concrete blocks having different shapes and sizes, depending upon the mold being utilized. Therefore, it should be understood that the finished block shown at  292  is exemplary only and the debris cleaning device of the present invention could easily be adapted for use on other types of concrete blocks having different shapes and sizes and passages located differently without departing from the scope of the invention. As best shown in  FIG. 10 , the plurality of passages  292   a  extend vertically through the block  292 , each passage likely containing debris needing to be flushed out. 
     Referring now to  FIGS. 12 and 13 , the conveyor system  290  includes a pair of parallel belts  296  which are spaced apart from each other by a predetermined distance. Each belt  296  is a continuous loop and could be of the link roller chain type. The conveyor system also includes powered pulleys  298  and idler pulleys (not shown) about which the belts  296  rotate. When energized, the powered pulleys  298  move the belts  296  and the materials on the belts, e.g., the finished block  292 . As best shown in  FIG. 12 , a plurality of support slats  294  extend in a direction perpendicular to the belts  296  and attach to the belts to provide support for the finished block  292  as it is conveyed on the conveyor system  290 . The support slats  294  are positioned to avoid contact with the passages  292   a  of the finished block  292 . 
     A pair of opposed stationary guides  300  are provided for guiding and positioning the finished block  292  as it is conveyed in the direction of travel indicted by arrow  303  over the debris removal device  302  of the present invention. The guides  300  include a slightly tapered configuration at the inlet end to precisely align the finished block as it is conveyed over the debris removal device  302 . Each opposed guide  300  is affixed, e.g., welded, to an angle-iron support beam  304 , which in turn is affixed, e.g., welded, to a vertical support post  306 , having a generally square cross-sectional shape, as best shown in  FIG. 12 . The vertical support posts are supported on the floor  305  of the facility in which the concrete block molding machine is located. Additional angle-iron beams  308  are affixed, e.g., welded, to each guide  300  to provide added support to the guide. The angle-iron beams  308  are affixed, e.g., welded, to connecting angle-iron beams  310 , which in turn, are affixed, e.g., welded, to the vertical posts  306 . 
     Referring now to  FIGS. 10 and 10A , the debris removal device  302  of the present invention is shown supported by a stationary support frame  314  located under the conveyor system  290 . The stationary support frame  314  includes a horizontal center plate  318  on which the debris removal device  302  is supported. A plurality of threaded shafts  322 , e.g., four, extend vertically upwardly from the horizontal center plate  318  and are affixed to the center plate  318  by any suitable means, e.g., bolts  326  passing through openings (not shown) in the center plate  318  and into the internally threaded bottom end of the shafts  322 . As best shown in  FIGS. 10A and 12 , the shafts  322  extends upwardly and through a circular opening in a corresponding collar  330 , the collar  330  being affixed, e.g., welded, to an upstanding L-shaped support beam  334 , the support beam  334  being affixed to the horizontal center plate  318  by any suitable means, e.g., welding. The horizontal center plate  318  is secured to the vertical support post  306  by any suitable means. As best shown in  FIG. 10 , the horizontal center plate  318  is affixed to an angle beam  338  using suitable hardware, e.g., nut, washer and hexagonal bolt. In turn, the angle beam  338  is affixed, e.g., welded, to a side plate  342 , which is affixed to the vertical support post  306  by any suitable means, e.g., welding. 
     Referring now to  FIGS. 14 and 15 , the debris removal device  302  includes a rectangular plate assembly  346  having a thickened central portion  350 , which is generally square in shape. The thickened central portion  350  may be an integral part of the plate assembly  346 , or may fabricated separately and secured to the plate assembly  346  by any suitable means, e.g., mounting hardware. At each corner of the rectangular plate assembly  346  a set of mounting holes is provided. In this case, each set includes four mounting holes arranged in a square pattern. The mounting holes enable attachment of bushings  354  to the underside of the plate assembly  346 . For example, as best shown in  FIG. 10A , each bushing  354  includes an upper shoulder to enable securement of the bushing  354  to the underside of the plate assembly  346  by utilizing a square-shaped fitting  358  in which the bushing  312  is held captive. The fitting  358  is secured to the underside of the plate assembly  346  utilizing conventional hardware, e.g., nuts, bolts, and washers. Each bushing  354  is shown as being cylindrical in shape and including a central opening  359  that corresponds in size with an opening  316  located centrally within the mounting holes at the corners of the rectangular plate assembly  346 . 
     Referring to  FIGS. 10 ,  10 A and  11 , the upwardly extending threaded shafts  322  of the horizontal plate  318  are shown extending through the central openings of the bushings  354  located in the corners of the horizontal plate  318 . In this manner, the debris removal device  302  is mounted to the stationary support frame  314 . Referring again to  FIGS. 14 and 15 , attached to the underside of the plate assembly  346  is an air manifold  362  having a plurality of ports  366 , each port being sized and configured to receive an air hose  370 . Each air hose  370  is connected to a coupling  374  which, in turn, is connected to an air nozzle  378  located on the top side of the plate  346 . As best shown in  FIG. 14 , each air nozzle  378  is mounted to a through opening located in a corner of the square shaped thickened central portion  350  of the rectangular plate assembly  346 . The air manifold  362  is connected to a system for delivering pressurized or compressed air (not shown) through two couplings  382  extending from the manifold  362 . The couplings  382  are connected to system for delivering pressurized or compressed air (not shown) in known ways using conventional hoses  385  ( FIG. 10 ) 
       FIGS. 10 and 11  illustrate operation of the debris removal device  302  of the present invention. As best shown in  FIG. 10 , several inflatable-deflatable air bellows  386  are situated between the horizontal plate  318  and the plate assembly  346  of the debris removal device  302 . Each air bellows  386  has a top and bottom mounting surface and is generally cylindrical in shape. Each air bellows  386  is made of an expandable material, such as rubber, and upon inflation, each is arranged to provide a lifting force to raise the rectangular plate assembly  346  from a retracted position ( FIG. 10 ) to an extended position ( FIG. 11 ). Couplings  390  and hoses  394  may be utilized to connect the air bellows  386  to the system for delivering pressurized air (not shown) to enable inflation of the air bellows  386 . In operation, the finished block  292  is conveyed over the debris removal device  302  in known ways using conventional hardware and software. 
     For example, as the support slat  294  continues to move with the conveyor belts  296 , an encoder (not shown) may transmit pulses to a processor (not shown) at a predetermined time interval, the processor keeping count of the number of pulses received from the encoder. By knowing the speed of the conveyor belts  296  and knowing the count of pulses received from the encoder, the location of a slat  294  supporting a finished block  292  may be determined with a high degree of accuracy. In this manner, a predetermined count of pulses received by the processor, e.g.,  1124  pulses, may be associated with a slat  294  supporting a finished block  292  reaching a predetermined position over the debris removal device  202 , as best shown in  FIG. 13 . Upon reaching this predetermined position, a signal may be sent from the processor to de-energize the powered pulleys  298  to bring the finished block  292  to a stop at the predetermined position over the debris removal device  302 . In addition, in advance of reaching the predetermined position, 50-100 pulses before reaching the predetermined count, a signal may be sent from the processor to decelerate the speed of the conveyor belts  296  to ensure more accurate positioning of the finished block  292  over the debris removal device  302 . 
     Simultaneously, upon reaching the predetermined position, the processor may send a signal to energize a solenoid (not shown) to deliver pressurized air to inflate the air bellows  386  which lifts the rectangular plate assembly  346  upwardly from the retracted position to the extended position, whereupon the air nozzles  378  enter the passages  292   a  of the block  292 . In  FIG. 13 , the air bellows  386  is shown in the inflated condition. Shortly thereafter, the system for delivering pressurized air is again actuated this time to deliver a short burst of pressurized air through the air nozzles  378  ( FIGS. 11 and 12 ) to remove debris from within the passages  292   a  of the finished block  292 . Thereafter, the solenoid is de-energized and the air bellows  386  is permitted to deflate, thus moving the rectangular plate assembly  346  from the extended position ( FIGS. 11 and 13 ) to the retracted position and to remove the air nozzles  378  from within the passages to enable continued conveyance of the finished block  292 . Upon return of the rectangular plate to the retracted position, a limit switch (not shown) may be moved from an open position to the closed position to reset the pulse counter to zero and re-energize the powered pulleys  298  to bring the next finished block  292  to the predetermined position over the debris removal device  302 . 
     It is understood that the device for removing debris from passages of manufactured modular blocks of the present invention and its constituent parts described herein is an exemplary indication of a preferred embodiment of the invention, and is given by way of illustration only. In other words, the concept of the present invention may be readily applied to a variety of preferred embodiments, including those disclosed herein. While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.