Abstract:
A concrete block splitter including an anti-backdrive holding blade, a rigid cutting table, and a lower cutting blade. The present invention provides a masonry splitter that splits blocks or bricks starting from the bottom side of the block, which typically includes the most dense material, so that a resultant fracture propagates along a uniform plane through the block. The anti-backdrive holding blade firmly clamps the block onto the rigid table during a splitting operation in such a manner that the blade does not move relative to the rigid table. Accordingly, during a splitting operation, the block is prevented from moving and the blade is prevented from deflecting. The cutting blade contacts the bottom surface of the block with sufficient force to propagate a fracture through the block. In the preferred embodiment, the splitter is mounted on self-powered wheels for easy installation and removal from an automated block production line.

Description:
BACKGROUND  
         [0001]    The present invention relates to a masonry block or brick splitter.  
           [0002]    Architectural building walls and landscape retaining walls are commonly constructed from individual concrete blocks having a rough or textured appearance on the outside face of the walls. The rough appearance is created by splitting a wide block into two parts with a splitting blade.  
           [0003]    Many machines have been developed to perform block splitting operations automatically. One such machine is disclosed in U.S. Pat. No. 2,881,753 to Entz. The Entz splitter includes upper and lower cutting chisels oriented in a vertical plane perpendicular to a cutting table on which a block is split. The cutting table includes a slot through which the lower cutting blade travels. The table is further vertically movable and pivots about the slot. To split a block, an in-feed conveyor first positions the block on the cutting table. The cutting chisel moves upward, contacts the block, and forces both the block and the cutting table upward so that the block contacts and raises the upper chisels until the chisels engage the contours of the upper surface of the block. Next, the lower cutting chisel forcibly drives the block against the upper chisel and simultaneously splits the block. The table pivots about the slot causing the slot to open up so that debris drops through the slot, away from the cutting blade.  
           [0004]    Known brick splitters, such as the one disclosed in Entz, suffer a number of shortcomings. First, the upper chisels and cutting table are movable with respect to one another. Therefore, during the cutting operation, the block is not clamped with a consistent force between the upper chisel and the table. Moreover, blocks must make a transition from the elevation of an in-feed conveyor to the upper chisel and back down to the conveyor which adds unnecessary movement in the process. Second, the use of a pivoting table in a splitting operation causes a block to bend or deflect as the lower cutting blade penetrates the block, which causes uneven split propagation. Third, conventional block cutters may inadvertently split weak or partially fractured blocks as the lower chisels lift the blocks upward toward the upper chisels.  
         SUMMARY OF THE INVENTION  
         [0005]    To overcome the aforementioned problems, the present invention takes advantage of a discovery that the lower surface of a block typically includes a higher material density than the upper surface because the higher density materials used to manufacture the block typically settle toward the bottom due to vibration used to compact the concrete mix while forming the block. Accordingly, it is undesirable to apply a splitting force with a blade to the top surface of the block, because this will cause the block to propagate at undesirable angles through the less dense materials and form a non-homogenous block face. Therefore, the present invention provides a masonry splitter including: a rigid table for supporting a block; an anti-backdriving blade for contacting a top surface of a block and pressing the block against the rigid fixed table; and a cutting blade opposedly aligned with the holding blade for splitting the block from the block&#39;s lower surface.  
           [0006]    In the preferred embodiment, the rigid cutting table and anti-backdriving screw member are mounted to a rigid support frame so that the two are stationary relative to one another during a splitting operation. The table is preferably rigid to prevent deflection and movement of the block as the block is split. Optionally, both the anti-backdrive screw member and rigid cutting table are adjustable to accommodate blocks of varying sizes and dimensions.  
           [0007]    In a more preferred embodiment, the anti-backdriving screw of the splitter is driven by a motor, hydraulics or pneumatics to retract and extend the holding blade away from and toward a block. In the extended position, the screw member firmly positions the holding blade against the top surface of a block and clamps (but does not cut) the block against a rigid table. The anti-backdriving screw member includes threads with a pitch sufficient to prevent the member from backdriving when a force is applied against the holding blade during a splitting operation  
           [0008]    The present invention provides a splitter that splits blocks starting from the most dense surface of the block to reduce irregular fracture propagation and therefore increase consistency of the rough appearance between blocks. The rigid table prevents block bending and deflection of the cutting blade during a splitting operation. The anti-backdriving screw member firmly presses and maintains the concrete block against the rigid table, so that the cutting blade can make a penetrating split from the bottom of the block.  
           [0009]    These and other objects, advantages and features of the invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiments and the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is shows a front view of a splitter in accordance with the preferred embodiment of the present invention;  
         [0011]    [0011]FIG. 2 is a top plan view of the splitter;  
         [0012]    [0012]FIG. 3 is a side elevational view of the splitter in a production line;  
         [0013]    [0013]FIG. 4 is a side elevation view of the splitter in a production line as the holding blade contacts an upper surface of a block;  
         [0014]    [0014]FIG. 5 is a side elevation view of the splitter in a production line as the block is initially split;  
         [0015]    [0015]FIG. 6 is a side elevation view of the splitter in a production line after the block is split; and  
         [0016]    [0016]FIG. 7 is a front view of an alternative embodiment of the splitter including side cutters. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    I. General Description  
         [0018]    A brick splitter in accordance with a preferred embodiment of the present invention is shown in FIGS. 1 and 2 and generally designated  10 . In general, the splitter  10  includes support frame  20  to which upper holding system  12 , rigid table  40  and lower cutting system  13  are mounted. The upper holding system  12  includes anti-backdrive holding blade  30  rigidly mounted to holding plate  32 , which is movably mounted to threaded drive  34 , which is movably mounted to drive motor  35 , which is rigidly mounted to support frame  20 . Rigid table  40  is likewise rigidly mounted to support frame  20  so that when a work piece is positioned on rigid table  40 , and holding blade  30  is pressed against the work piece, that work piece is fixedly clamped between the table  40  and the holding blade  30 , which may be straight or a series of angled segments. The cutting blade  50 , which may also be straight or a series of angled segments, of the lower cutting system  13  is disposed below the rigid table  40  so that during a cutting operation it travels upward through an aperture  42  in the rigid table  40  to contact the lower portion of a work piece clamped between the table and the holding blade  30 . The lower hydraulic system  56  drives the cutting blade and pressed against the lower portion of that work piece with sufficient force to fracture the work piece through a vertical plane or series of consecutive vertical planes coincident with holding blade  30 .  
         [0019]    With further reference to FIG. 3, the splitter is preferably movable on tracks  70  via wheels  72  which are driven by power motors  74  mounted to the support frame  20 . Located on opposite feed and discharge sides of the splitter  10  are in-feed conveyor  14  and a discharge or outflow conveyor  16 , which transports blocks, bricks or other masonry units toward the splitter  10  and after cutting or splitting thereof, transport split material from the splitter  10 , respectively. Preferably a block split by the splitter are loaded onto the conveyor  14  immediately after they are manufactured and cured so that the blocks  6  are oriented with the more compact and higher density aggregate portion  4  of the block material is on the “bottom,” and the low density portion  2  of the block material is on the “top.” This is because in conventional block making processes, the higher density ingredients in a concrete mix settle out toward the bottom of the block.  
         [0020]    In the preferred embodiment, when the block  6  is positioned on rigid table  40  and held in place by holding blade  30 , the cutting blade  50  may fracture the block  6  from the bottom side adjacent the high density portion. Fracturing a block in this way propagates fractures consistently along a predetermined plane and reduces geometric variations of the resultant surfaces along the split. Because the splitter  10  of the present invention does not cut into the upper portion  2  of the block with the holding blade  30 , no objectionable tooling marks are scored on the resultant block face and the block is cut uniformly on a desired relatively homogeneous plane to create an aesthetically pleasing face on the block.  
         [0021]    II. Cutting Table  
         [0022]    FIGS.  1 - 3  show the table  40  mounted to support frame  20 . The table  40  is preferably rigid so that as blocks are cut on it, it does not allow the blocks to bend or deflect, and subsequently cause a cutting blade to leave objectionable tooling marks on the split face. The table may be a single or multiple pieces of hardened steel or other material suitable for repeatedly contacting abrasive masonry units without significant wear. The rigid table  40  is preferably fixedly mounted to support frame  20  with bolts. However, any other fastening means may be used, for example, screws or by welding. The rigid table is configured so that it substantially supported on both sides by the support frame  20 . Accordingly, the rigid table  40  does not flex or deflect substantially when a block  6  is clamped down upon it by the holding blade  30 . The table  40  includes an aperture  42  through which cutting blade  50  may travel and contact the lower surface of a block  6  resting on the table and fracture that block. Optionally, the aperture  42  may be a slot defined by the table or the surface of the table may be divided into two separate and parallel members through which the cutting blade  50  may travel.  
         [0023]    In operation in a production line, the table  40  is preferably along the same horizontal plane as the upper surfaces of conveyor systems  14 ,  16  as depicted in FIG. 3. The conveyor systems  14 ,  16  or the table  40 , or the support frame  20  may include bridges  17 ,  18  to provide support for block  6  as it moves to and from the fixed table from the in-feed conveyor  14  and discharge conveyor  16 .  
         [0024]    III. Upper Holding System  
         [0025]    With reference to FIGS. 1 and 3, the upper holding system  12  includes holding blade  30 , holding plate  32 , threaded coupler  38 , threaded member  34 , drive motor  35  and thrust bearing  36 . The drive motor  35  is fixedly mounted to support frame  20  and receives threaded drive member  34  in a rigid coupling, capable of rotating the threaded member  34  within the coupler  38  but not allowing the threaded member to move in relation to the drive motor. Threaded member  34  is preferably supported by thrust bearing  36  which is fixedly mounted to support frame  20 . The thrust bearing  36  is of any commercially available rotating mechanism that allows the threaded member to rotate within when driven by drive motor  35 , but prevents the threaded member  34  from translating vertically on the axis of the threaded member.  
         [0026]    The threaded member  34  may be any threaded device including a pitch or structure that engages the threaded coupler  38  and drive motor  35  in such a manner to prevent the holding blade  30  from being driven away from a work piece  6  as it is split by the lower cutting blade  50  during a splitting operation. Such a mechanism is referred to herein as “anti-backdrive mechanism.” Optionally, the configuration of the threaded drive  34  and coupler  38  may be reversed, that is, the coupler may be fixedly mounted to the support frame  20  and the drive motor  35  may be mounted to the holding plate  32  (not shown). This configuration would operate similar to that described above, except that the drive motor interacts with the threaded member  34 , and in particular, the pitch of threads thereon, so that the threaded member  34  does not rotate within the drive motor  35  thereby causing the holding plate  32  and holding blade  30  to retract from a work piece as it is split from the bottom by the cutting blade  50 .  
         [0027]    Preferably, the threaded member  34  is an acme screw having threads at a pitch sufficient to achieve the function as described above. Optionally, a ball screw or other similar threaded device may be substituted for the Acme screw.  
         [0028]    In the preferred embodiment of FIGS. 1 and 3, the coupler  38  is secured to the holding plate  32 . The holding plate  32  is preferably movable within the vertical plane that is coincident with the movement of the cutting blade  50 . To ensure the holding plate and cutting blade  30  move within this plane, the holding plate is guided by guides  33  which are secured to the support frame  20 .  
         [0029]    The holding blade  30  is preferably mounted to the holding plate  32  with any structure so that the blade may be easily replaced. For example, the blade  30  may be mounted with bolts or other fasteners. The blade  30  is preferably a typical masonry cutting blade.  
         [0030]    As depicted in FIGS. 1 and 3, the holding blade  30  is in a retracted position so that blocks  6  may freely pass onto the rigid table  40  for cutting. The distance between the holding blade  30  and the work piece  6  may be adjusted as desired. Optionally, manual or automatic adjusting motors or brackets may be mounted to the upper holding system  12  to move that system downward to accommodate different sized and dimensioned work pieces  6 . The holding blade is drivable by drive motor  35  to a position, an “extended” position where it stalls and clamps down against the top surface  3  of the block  6  thereby clamping the block  6  between the holding blade and the rigid table  40  as described in further detail below.  
         [0031]    The drive motor  35  rotates the threaded member  34 . Any conventional pneumatic, hydraulic or electrically powered motor may be used. As the motor rotates the threaded member  34 , the coupler  38  moves relative to the longitudinal axis of the threaded member  34  to extend or retract the holding blade  30  toward or away from the rigid table  40 .  
         [0032]    As will be appreciated by those skilled in the art, the upper holding system  12  may be in duplicate, that is, more than one upper cutting system may be mounted to the support frame  12 , adjacent one another to allow splitting of multiple concrete blocks simultaneously on the table. Optionally, the holding blades  30  of the these multiple upper holding systems may be linked together to split individual single, large masonry units. As will be appreciated, if multiple upper holding systems  12  are included in the splitter  10 , then a corresponding number of cutting systems  13  may likewise be used in the splitter  10 . Optionally, single large cutting system  13  may be used in conjunction with multiple upper holding systems  12 , or conversely, multiple cutting systems  13  may be used with a single upper holding system  12  as desired.  
         [0033]    IV. Cutting System  
         [0034]    With reference to FIGS. 1 and 3, the cutting system  13  generally includes cutting or lower blade  50  which is mounted to thrust plate  54  which is further mounted to cutting press  56  which is itself mounted to the support frame  20 . The cutting press  56  is preferably a hydraulic, pneumatic, cam-driven or electric power press capable of driving the thrust plate  54  and attached cutting blade  50  upward into a work piece with sufficient force to split the work piece into separate parts.  
         [0035]    The thrust plate  54  is preferably mounted to a ram of the cutting press  56 . The thrust plate  54  preferably travels in a plane, as depicted, a vertical plane, coincident with the holding blade  30  of the holding system  12 . The thrust plate  54  is preferably guided by guides  53  which are fixably mounted to the support frame  20 . The cutting blade  50  is extendable and retractable by the cutting press  56  a sufficient distance to exert the force necessary to split a work piece; that is, the cutting blade  50  is extendable through aperture  42  of the rigid table  40  to contact and split a work piece clamped on the table  40  by the holding blade  30 .  
         [0036]    The cutting blade  50  may be constructed of any commercially available material suitable for cutting masonry units. Optionally, the cutting blade is fastened to the thrust plate  54  so that it may be easily replaced, such as with bolts or other fasteners as described above in connection with the holding blade  30 .  
         [0037]    V. Portable Splitter  
         [0038]    As depicted in FIGS.  1 - 3 , the splitter  10  is outfitted with wheels  72  so that the splitter may be moved into and out from various conveyor systems for maintenance or production line charges. The extremely narrow profile of the splitter  10  of the present invention allows this additional option. Preferably, wheels  72  are rotatably mounted to the support frame  20 . The wheels may be of any configuration. For example, the wheels  72  may be substituted with lockable casters. However, as shown, they are keyed to fit on track system  70 . Wheels  72  are preferably mounted to the support member  20  with mounting bracket  73  in such a manner that the support frame  20  may be adjusted vertically to accommodate different height conveyor systems. Optionally, this feature may be absent from the splitter  10 .  
         [0039]    Preferably, the wheels  72  are powered by independent motors that are mounted to the support frame  20  or mounting bracket  73 . Similarly, a single motor used in conjunction with axle shafts, sprockets, chains, or other commercially available power transmission components may be used to drive one or more wheels. As will be appreciated, the motors may be absent and the splitter  10  may be manually movable. These motors may be any commercially available motor suitable for powering drive wheels and moving the splitter  10 .  
         [0040]    VI. Side Cutting Blades  
         [0041]    Optionally, as depicted in FIG. 7, the splitter  10  of the present invention may be further retrofitted to include side cutters  80 . The side cutters include a side cut drive  86  coupled to side cut plates  84 , to which side cut blades  82  are mounted. The components of the side cutters are similar to that of the cutting system  13  described above and therefore for the sake of brevity will not be explained again here. Notably, the side cutters extend and retract side cutting blades  82  within the plane coincident with the holding blade  30  and the cutting blade  50  and assist in splitting work pieces during a splitting operation. Optionally, manual or automatic adjusting motors or brackets may be mounted to the side cutters  80  to move that system horizontally to accommodate different sized and dimensioned work pieces  6  (not shown).  
         [0042]    VII. Control System  
         [0043]    With further reference to FIG. 3, the splitter  10  may include a control system  24 , including a microprocessor  26  and sensor  28 , which controls advancement and feed of blocks  6  onto the cutting table  40  and subsequent holding and splitting operations performed by holding system  12  and cutting system  13 . Microprocessor  26  may be any commercially available programmable logic computer (PLC). Sensor  28  may be a photosensor or other commercially available sensor to detect positioning of blocks  6 . Any number of sensors placed virtually anywhere in relation to the conveyor and/or splitter may be used to control block flow.  
         [0044]    VIII. Operation of the Splitter  
         [0045]    With reference to FIGS.  3 - 6 , the splitting operation carried out by splitter  10  will now be described. FIG. 3 depicts in-feed conveyor system  14  feeding block  6  onto the rigid table  40  of the splitter  10 . As noted above, the block  6  being split is preferably a recently manufactured block having a more dense portion  4  disposed on the lower surface thereof so that that lower surface  5  contacts the rigid table  40  of the splitter  10  and rests thereupon.  
         [0046]    The holding system  12  depicted in FIG. 3 is in its retracted position where the holding blade  30  allows blocks to travel across and onto the rigid table  40 . Optionally, the positioning system  24  may be used in conjunction with the splitter to variably feed and position the blocks  6  onto the rigid table  40  in any desired manner. For example, if the blocks are to be split in half, the positioning system  24  may position the block so that its mid-portion is positioned precisely below the holding blade. Likewise, if the block is to be cut into thirds, the positioning system  24  would accurately position the block so that it is positioned below the holding blade at positions corresponding to thirds of the block.  
         [0047]    In the preferred embodiment, after the block  6  is positioned on the rigid table  40 , the drive motor  35  powers “on,” thereby rotating the threaded member  34 . Accordingly, the holding blade  30  descends downward into contact with the upper surface  3  of product  6  due to the interaction of the threaded member  34  with the corresponding threaded coupler  38 .  
         [0048]    With reference to FIG. 4, as the holding blade  30  contacts the upper surface  3  of the block  6 , it drives the block  6  downward against the table  40 , thereby clamping the block between the holding blade  30  and the table  40 . Because of the pitch of the threaded member  34  and its interaction with the mated threaded drive coupler  38 , that threaded member  34  will not backdrive, and consequently the holding blade  30  will not retract in subsequent steps where forces are exerted against the block  6 . The drive motor  35  drives the holding blade down  30  with sufficient force to contact the top surface  3  and clamp the block, but not split the top surface  2  of the block. At this point, the drive motor  35  stalls out. The motor is held energized to maintain a constant clamping force on the block.  
         [0049]    In another step depicted in FIGS. 5 and 6, the cutting blade  50  is extended upward by cutting press  56  through the aperture  42  and the rigid table  40  with sufficient force to split the block  6  starting from the more dense portion  4  adjacent the lower surface  5  of the block. Accordingly, a crack  90  propagates from the lower surface of the block to the upper surface of the block toward the holding blade. Thus, the resultant faces of the block propagate along the desired vertical plane between the holding blade  30  and the cutting blade  50  without significant deviations from the vertical plane. After the crack  90  has fully extended across the depth of the block  6 , the faces  92  and  93  are exposed. These faces do not include significant geometric variation from one another. Moreover, because the holding blade  30  is maintained in fixed relation with respect to the table  40 , the holding blade  30  does not penetrate into the block to leave objectionable tooling marks on the resultant exposed faces  92  and  93 . Finally, because the table  40  remains rigid throughout the splitting operation, the block does not bend or deflect during the cutting operation which may cause an undesirable angle of crack propagation or cause the tooling to leave objectionable marks on the surfaces  92  and  93  of the block  6 .  
         [0050]    After a block is then satisfactorily split by the splitter  10 , the control system  24  causes the cutting blade  50  and holding blade  30  to retract to their unextended positions, as depicted in FIG. 3, and another block is fed unto the rigid table  40  to continue the process.  
         [0051]    In the alternative embodiment depicted in FIG. 7, the splitting operation, as described above, is similar except that as the cutting blade  50  contacts the lower surface of the block  5 , the side cutters  82  likewise contact the side of the block and almost simultaneously exert a splitting force with the cutting blade  50  to split the blocks from the bottom  5  and the sides as well.  
         [0052]    The above descriptions are those of the preferred embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular.