Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS, IF ANY  
         [0001]    Not applicable.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable.  
         REFERENCE TO A MICROFICHE APPENDIX, IF ANY  
         [0003]    Not applicable.  
         BACKGROUND OF THE INVENTION  
         [0004]    1. Field of the Invention.  
           [0005]    The present invention relates, generally, to a core puller for molds used in conjunction with concrete block manufacture. More particularly, the invention relates to an integral core puller/mold assembly. Most particularly, the invention relates to a system, apparatus and method for the rapid pulling of cores from a compact, automatic, integral core puller/mold assembly.  
           [0006]    2. Background Information.  
           [0007]    The background technology, in general, includes apparatus and/or methods for pulling core bars or similar devices from a mold used to form a concrete block. High production concrete block machines operate rapidly and in those instances in which multiple blocks are molded with grooved lower faces, it is necessary to provide multiple core parts which can be retraced from the molds at high speed to permit the newly molded blocks to be stripped from the molds and lowered by pallet onto a conveyor for transportation to curing or storage.  
           [0008]    In the past, core pullers have been used which provide a single, heavy duty ram having a header actuated by the hydraulic ram and carrying multiple core bars which are inserted into, and retracted from, the molds. Such core pullers are heavy, bulky and require much space. In general, the devices are custom manufactured to suit a particular block machine and are not readily adapted for use with other block machines.  
           [0009]    Machines of this type tend to be subject to guidance problems with respect to the elongate core bars and to vibration problems resulting from intense vibration of the block machine during the molding process. The use of a single hydraulically operated ram results in a relatively slow acting core puller assembly that interferes with normal production.  
           [0010]    Other core pullers employ multiple hydraulic rams to achieve core pulling during production. All of these core pullers are provided as “add-on” attachments that require extra space and precise alignment with the mold to achieve satisfactory results.  
           [0011]    This technology is believed to have significant limitations and shortcomings, including, but not limited to:  
           [0012]    a. Large space requirements for the “add-on” attachment.  
           [0013]    b. Precise alignment requirements for proper function.  
           [0014]    c. Extended setup time when changing molds.  
           [0015]    For this and other reasons, a need exists for the present invention.  
           [0016]    The invention provides an integral core puller/mold assembly, which is believed to fulfill the need and to constitute an improvement over the background technology.  
           [0017]    All US patents and patent applications and all other published documents mentioned anywhere in this application are incorporated by reference in their entirety.  
         BRIEF SUMMARY OF THE INVENTION  
         [0018]    The present invention provides an apparatus and method for molding concrete blocks employing a block molding system.  
           [0019]    In one embodiment, the apparatus includes a core puller/mold assembly comprising a mold frame containing a block mold having a mold cavity. A pair of cylinders is present, with each cylinder fastened to an opposed, exterior side of the mold frame. The cylinders each have a rod that extends beyond the mold frame joining the opposed, exterior sides. A core bar mounting bracket is fastened between the cylinder rods. At least one core bar is secured to the mounting bracket, with the bar extending toward the mold cavity. The at least one core bar is removed from the mold cavity with the cylinder rods extended and traverses the mold cavity with the cylinder rods retracted.  
           [0020]    In another embodiment, the apparatus includes a core puller/mold assembly comprising a mold frame containing a block mold having a mold cavity. A top plate member with a mold cavity aperture therein, is secured atop the mold frame. A pair of cylinders is present, each cylinder fastened to an opposed, exterior side of the mold frame. The cylinders each have a rod extending beyond the mold frame joining the opposed, exterior sides, with the cylinder rods passing through a rod aperture in the mold frame. The cylinder rods are perpendicular to the vertical, interior sides of the cavity. A core bar mounting bracket is fastened between the cylinder rods. At least one core bar is reversibly secured to the mounting bracket and extends toward the mold cavity through a core bar aperture in the mold frame. The at least one core bar is removed from the mold cavity with the cylinder rods extended and traverses the mold cavity with the cylinder rods retracted.  
           [0021]    The method of molding a block includes the steps of providing a core puller/mold assembly comprising a mold frame containing a block mold having a mold cavity. A pair of cylinders is present, with each cylinder fastened to an opposed, exterior side of the mold frame. The cylinders each have a rod that extends beyond the mold frame joining the opposed, exterior sides. A core bar mounting bracket is fastened between the cylinder rods. At least one core bar is secured to the mounting bracket, with the bar extending toward the mold cavity.  
           [0022]    The cylinder rods are retracted with the at least one core bar traversing the mold cavity. The mold is filled with fill mix, vibrated and pressure applied, to form the block within the mold. The at lease one core bar is removed from the mold by extending the cylinder rods. The block is removed from the mold by vertical movement of a plunger assembly through the mold cavity.  
           [0023]    The features, benefits and objects of the invention will become clear to those skilled in the art by reference to the following description, claims and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0024]    [0024]FIG. 1 is a perspective view of the core puller/mold assembly of the present invention.  
         [0025]    [0025]FIG. 2 is a perspective view of the core puller/mold assembly of FIG. 1 with the top plate member removed.  
         [0026]    [0026]FIG. 3 is an exploded perspective view of the core puller/mold assembly of FIG. 1.  
         [0027]    [0027]FIG. 4 is a schematic representation of a block machine incorporating the core puller/mold assembly of the present invention.  
         [0028]    [0028]FIG. 5 is a perspective view of the plunger assembly used to remove a block from the core puller/mold assembly of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0029]    FIGS.  1 - 3  show an embodiment of the present invention, generally indicated by the reference numeral  10 . The assembly  10  is shown fully assembled in FIG. 1 and with the top plate member  200  removed in FIG. 2. FIG. 3 provides an exploded view of the assembly  10  of FIG. 1, in which a generally rectangular mold frame  15  is composed of a side bar member  20 , an opposed stop bar member  25  and a pair of spaced apart, outside division plate members  30 , each having a top edge  35 . The components of the mold frame  15  are each generally rectangular and secured together with each end of the side bar member  20  and stop bar member  25  extending beyond the plane of attachment of each of the two division plate members  30 . The side bar member  20  and stop bar member  25  each has a pair of vertical retaining slots  40 , each slot  40  with a slot aperture  45  therein. The division plate members  30  include a retaining peg  50  at each end. Each plate member end fits into one of the retaining slots  40  with the retaining peg  50  inserted into the slot aperture  45 . The bar members  20 ,  25  and plate members  30  are further secured together by retainer straps  55 , secured between the bar members  20 ,  25  beneath each plate member  30 .  
         [0030]    The mold frame  15  is sized to accept a plurality of wear liners  60  that define the concrete block produced by the core puller/mold assembly  10 . The wear liners  60  are fabricated from steel alloy for strength and resistance to abrasion by the concrete fill used to produce each block. The wear liners  60  have planar top  65  and bottom  70  surfaces and fit together within the mold frame  15 , such that the liner interior surfaces  75  define a mold cavity  80  that produces the concrete block. The mold cavity  80  is open at both the top and bottom, with vertical interior surfaces  75 .  
         [0031]    The interior surface of the bar members  20 ,  25  and plate members  30  each contain a horizontal channel  85 . The wear liners  60  are provided with alignment ridges  90  on their exterior surfaces  95 , which fit into the horizontal channels  85  of the bar members  20 ,  25  and plate members  30 . Additionally, the alignment ridges  90  are provided with a number of threaded blind holes  100  that align with apertures  105  in the channels  85  for securing the various wear liners  60  to the bar member  20 ,  25  and plate members  30  with threaded fasteners (not shown). Thus, the mold frame  15  and associated wear liners  60  provide a structurally rigid mold portion that is easily disassembled for changing wear liners  60  to produce various shaped concrete blocks.  
         [0032]    An actuation cylinder  150  is secured horizontally to an exterior side of each division plate member  30 . Each actuation cylinder  150  is secured thereto, by a pair of cylinder mounts  155  and associated mount spacers  160 . The actuation cylinders  150  are sized to fit between the ends of the bar members  20 ,  25  that extend beyond each division plate member  30 . Each actuation cylinder  150  has a moveable rod member  165 , extending from one end thereof, through a rod aperture  170  in the side bar member  20 . The cylinder rod members  165  are fastened to a core mounting bracket member  175  via rod connectors  180  at each end of the bracket member  175 .  
         [0033]    At least one core bar member  185  is fastened at one end to the bracket member  175 . In this embodiment, two core bar members  185  are fastened to the bracket member  175 , with the core bar member  185  extending through a core slot  190  in the side bar member  20 . The bracket member  175  and core slot  190  are positioned so as to direct the core bar member  185  along one surface of the block mold. In this embodiment, each core bar member  185  traverses the mold cavity  80  at opposite ends thereof, adjacent the top plate member  200 . The cylinder rod members  165  and core bar members  185  are sized so that, with the cylinder rod members  165  extended from the cylinders  150 , the core bar members  185  are completely removed from the mold cavity  80 , and with the cylinder rod members  165  retracted into the cylinders  150 , the core bar members  185  extend completely across the mold cavity  80 . The core bar members  185  are, preferably, reversibly fastened to the bracket member  175  should replacement of the core bar members  185  be required.  
         [0034]    To further reinforce the core puller/mold assembly  10 , a top plate member  200  is secured atop the mold frame  15 . The top plate member  200  is planar with a core aperture  205  sized to be larger than the open top of the mold interior cavity  80 . The top plate core aperture  205  is sized to allow the division plate members top edges  35  to extend there through, along opposed edges thereof. The top plate member  200  also includes apertures  210  for fastening the plate member  200  to the side bar and stop bar members  20 ,  25  for added structural stability. The top plate member  200  also includes upwardly extending edges  215  on three sides and a downwardly extending fourth edge  220  for low level access to the open top of the mold cavity  80 .  
         [0035]    A block machines of the type with which the core puller/mold assembly  10  is used is shown schematically in FIG. 4. The block machine  400  is supplied with pallets  405  by a conveyor  415 . The pallets  405  are raised into position, as by a lower lift unit  410 . The molds are filled by a metering chute (not shown) and an upper stripper head unit  420 , having a movable height pin  430  connected thereto, which is lowered into position until the height pin  430  engages a relatively fixed height pin  440 . The height pins  430  and  440  determine the height of the blocks and also provide electrical contacts, which close to initiate termination of the vibration cycle and also actuate the stripping action of the head unit  420  by way of the delay timer  445 . The delay timer  445  also sends a signal to the core puller/mold assembly  10 , so that the core bars  185  are retracted prior to the stripping action. The safety switch actuator  425  mounted to the core bar mounting bracket  175  of the assembly  10  is incorporated into the block machine circuitry to preclude stripping of the mold cavity  80  until the safety switch  425  is closed.  
         [0036]    The sequence of operation begins with the core bars  185  fully extended into the mold cavity  80 . When the core bars  185  are in place in the mold assembly  10 , a pallet member  405  is moved into position below the cavity  80 . Following this, the mold cavity  80  fills with concrete, and vibration of the block machine commences. Engagement of the height pins  430  and  440  initiates termination of vibration. Prior to the complete termination of vibration, the block machine delay timer  445 , actuated by engagement of the height pins  430 ,  440 , sends a signal to the drive unit timer  435 , which actuates the air supply to the cylinders  150 . The core bars  185  are retracted, when drive unit timer  435  times out, by supplying air to the cylinder front air inlets at the same time as the vibration is completed, since stripping action begins very shortly, about four-tenths ({fraction (4/10)}) of a second, after completion of vibration. The completed blocks are lowered with the pallet member  405  and transported by the conveyor  415  to storage or curing. When the drive unit timer  435  again times out, air is supplied to the cylinder rear air inlets, and the core bars  185  re-enter the mold assembly liner cavity  80  shortly before another pallet member  405  is raised into position for the next cycle.  
         [0037]    The plunger assembly  300  used to remove the formed block from the core aperture  80  of the core puller/mold assembly  10  is shown in FIG. 5. The plunger assembly  300  is positioned above the block-filled core aperture  80  with the stripper shoe  310  contacting the block upper surface. The downwardly extending edge  220  of the top plate member  200  provides clear, low-level access for the plunger assembly  300  to the top of the mold assembly  10 . The stripper shoe  310  is configured to match the core aperture  80 , such that downward movement of the plunger assembly  300  strips the block cleanly from the mold cavity  80 . The stripper shoe  310  is secured to a plunger weldment  320  which, in turn, is fastened to a head plate  330 . The plunger weldment  320  footprint is smaller than the stripper shoe  310 , so as to pass into the mold cavity  80  without contacting the vertical surfaces  75  of the mold. The head plate  330  provides for attachment of the plunger assembly  300  to the stripper head unit  420  of the block machine  400 .  
         [0038]    The descriptions above and the accompanying drawings should be interpreted in the illustrative and not the limited sense. While the invention has been disclosed in connection with an embodiment or embodiments thereof, it should be understood that there may be other embodiments which fall within the scope of the invention as defined by the claims. Where a claim, if any, is expressed as a means or step for performing a specified function, it is intended that such claim be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof, including both structural equivalents and equivalent structures, material-based equivalents and equivalent materials, and act-based equivalents and equivalent acts.

Technology Category: 7