Abstract:
A method and apparatus for separating components of wet cement. A reclaim gate includes a tumbler flange with a tumbler flange opening. A strainer having strainer openings passes sand, rinse water, and cement slurry while blocking cement aggregates. A fixed plate entraps the strainer in place. The fixed plate has a reclaim aperture aligned with the screen. A rotating turn plate having a matching reclaim aperture is adjacent the fixed plate. A gate actuator retains the turn plate adjacent the fixed plate such that the turn plate can turn to selectively align the turn plate aperture with the fixed plate aperture. In use the aggregates are blocked by the screen, the sand passes through and is filtered; the slurry passes through and is collected and settled. The aggregates, sand, and rinse water can be recovered.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/101,512, which was filed Jan. 9, 2015, the entire disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The presently disclosed subject matter is directed to concrete. More particularly, it is directed to recycling wet cement located in ready-mix trucks to separate sand, concrete slurry, and concrete aggregates from the wet cement. 
     BACKGROUND OF THE INVENTION 
     The use of concrete as a building material has exploded in recent years. Nowadays it is not at all uncommon to find concrete used not only in driveways and sidewalks but also in building construction, patios, retaining walls, and the like. Concrete&#39;s long life coupled with no-care beauty and affordable cost make it a very popular material for many such applications. 
     Concrete is often delivered to project sites by ready-mix concrete trucks. As it can be difficult to determine exactly how much concrete is needed for a particular job and since no one wants to run out of concrete during a pour it is not at all uncommon for a job site to order more ready-mix concrete then is needed and then to return the excess to the concrete plant. Such excess concrete is usually separated back into its constituent components using an on-site concrete re-claimer. That way the concrete can be used in future concrete batches. 
     On-site re-claimers are generally expensive, require a separate power source, and are fixed regarding their location and ability to handle multiple trucks. Accordingly, there exists a need for an apparatus and a method of reclaiming concrete from ready-mix concrete trucks without using a fixed site concrete re-claimer. Ideally such a concrete recycling apparatus and method would provide for reclaiming concrete directly from ready-mix concrete trucks in a manner which is quick, easy, and effective. 
     SUMMARY OF THE INVENTION 
     The principles of the present invention provide for an apparatus and method for reclaiming excess concrete from ready-mix concrete trucks. That apparatus and method avoids the need for a dedicated fixed site concrete re-claimer while enabling quick, easy and effective reclaiming of mixed concrete. 
     According to one (1) aspect the invention takes the form of a reclaim gate having a tumbler flange with a tumbler flange opening, a strainer adjacent the tumbler flange ad having a central strainer pivot aperture and a screen with strainer openings, and a fixed plate entrapping the strainer adjacent the tumbler flange. The fixed plate is rigidly attached to the tumbler flange by threaded fasteners. The fixed plate includes a central fixed plate aperture and a fixed plate reclaim aperture that is aligned with the screen. A rotating turn plate having a central turn plate aperture and a turn plate reclaim aperture is adjacent the fixed plate. A gate actuator passes through the central turn plate aperture, through the central fixed plate aperture and into the central strainer pivot aperture so as to retain the turn plate adjacent the fixed plate such that the turn plate can turn to selectively align the central turn plate aperture with the central fixed plate aperture. 
     In practice the tumbler flange includes threaded fastener apertures for receiving the threaded fasteners. Beneficially the tumbler flange is welded to a truck. The strainer openings should not be large enough to allow wet cement aggregates to pass through but large enough to allow sand, slurry, and rinse water to pass through. The fixed plate may include an “L”-shaped perimeter for entrapping the strainer adjacent the tumbler flange. Preferably the central turn plate aperture includes a keyway and the gate actuator includes a key that fits into the keyway such that turning the gate actuator turns the turn plate. A nut fastener can retain the gate actuator to the fixed plate and to the turn plate. 
     According to another aspect the invention takes the form of a ready mix cement truck having a rotating tumbler on a truck frame and having a tumbler aperture. A tumbler flange having a tumbler flange opening is aligned with the tumbler aperture. The tumbler flange is permanently attached to the tumbler. Also included is a strainer adjacent the tumbler flange with the strainer having a central strainer pivot aperture and a screen having strainer openings. A fixed plate entraps the strainer adjacent the tumbler flange. The fixed plate is rigidly attached to the tumbler flange by threaded fasteners. The fixed plate includes a central fixed plate aperture and a fixed plate reclaim aperture that is aligned with the screen. A rotating turn plate having a central turn plate aperture and a turn plate reclaim aperture is adjacent the fixed plate. A gate actuator passes through the central turn plate aperture, through the central fixed plate aperture and into the central strainer pivot aperture to retain the turn plate adjacent the fixed plate such that the turn plate can turn to selectively align the central turn plate aperture with the central fixed plate aperture. 
     In practice the tumbler flange includes threaded fastener apertures for receiving the threaded fasteners. Beneficially the tumbler flange is welded to the truck. The strainer openings should not be large enough to allow wet cement aggregates to pass through but large enough to allow sand, slurry, and rinse water to pass through. The fixed plate may include an “L”-shaped perimeter for entrapping the strainer adjacent the tumbler flange. Preferably the central turn plate aperture includes a keyway while the gate actuator includes a key that fits into the keyway such that turning the gate actuator turns the turn plate. A nut fastener can be used to retain the gate actuator to the fixed plate and to the turn plate. 
     According to yet another aspect the invention takes the form of a method for reclaiming sand and concrete aggregates from wet cement located in a ready mix cement truck. That method is practiced by locating a ready mix cement truck having a tumbler adjacent a reclaim area and then rotating the tumbler to enable constituent components of wet cement to come out of an opening. Next, a screen having screen openings that are too small for concrete aggregates to pass through is located adjacent the opening. The wet cement in the tumbler is then rinsed with rinse water to dilute the wet cement. Sand, concrete slurry, and rinse water is then allowed to pass through the screen openings and into the reclaim area. Sand is then filtered out in the reclaim area such that the sand remains in the reclaim area. The slurry and rinse water are passed through a reclaim area filter and the slurry and rinse water are collected. The slurry is allowed to settle out and the sand, rinse water, and cement aggregate are recovered. 
     In practice the reclaim area has a non-permeable surface while reclaim filtering uses a hay bale perimeter around the reclaim. A secondary filter can then be placed on the hay bale perimeter and the hay bales can be stabilized in place. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings in which like elements are identified with like symbols and in which: 
         FIG. 1  is an isometric view of a cement truck  200  at a reclaim area  20  which is engaged in an inventive recycling method  10  that is in accordance with the preferred embodiment of the present invention; 
         FIG. 2  is an exploded view of an inventive reclaim gate  50  on a tumbler  210  of a cement truck  200  that is useful when practicing the recycling method  10 ; and, 
         FIG. 3  is a sectional view of the reclaim gate  50 . 
     
    
    
     DESCRIPTIVE KEY 
     
         
         
           
               10  method 
               20  reclaim area 
               30  hay bales 
               35  silt fence/reclamation structure 
               40  stabilizer blocks 
               50  reclaim gate 
               55  tumbler flange aperture 
               60  tumbler flange 
               62  weld 
               65  fastener aperture 
               70  strainer 
               75  strainer reclaim aperture 
               77  strainer pivot aperture 
               80  fixed plate 
               85  fixed plate reclaim aperture 
               90  plate fastener 
               95  fixed plate pivot aperture 
               100  turn plate 
               105  turn plate reclaim aperture 
               110  turn plate pivot aperture 
               112  keyway 
               113  perimeter edge 
               115  gate actuator 
               117  key 
               118  threaded region 
               120  nut fastener 
               125  actuator tool 
               130  aggregate 
               140  sand 
               150  slurry 
               160  rinse water 
               200  cement truck 
               210  tumbler 
               215  tumbler aperture 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiment of the present invention is herein depicted within  FIGS. 1 through 3 . However, the invention is not limited to the specifically described embodiment. A person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one (1) particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” as used herein do not denote a limitation of quantity, but rather denote the presence of at least one (1) of the referenced items. 
     Referencing  FIGS. 1-3 , the present invention describes a cement recycling method  10  and a reclaim gate  50  that is suitable for practicing the method  10 . The method  10  achieves separation of a batch of mixed cement into its constituent components, specifically an aggregate  130 , sand  140 , and a portland/water slurry  150 . The aggregate  130 , namely gravel, remains within a tumbler  210  of a ready-mix cement truck  200  while the sand  140  and the slurry  150  are rinsed from the tumbler  210  using rinse water  160 . Upon exiting the reclaim gate  50  the constituents of the sand  140  and slurry  150  enter an adjacent reclaim area  20  for further processing such as, but not limited to: filtering, disposal, storage, and collection. 
       FIG. 1  presents an isometric view of a ready mix cement truck  200  at a reclaim area  20 . The cement truck  200  is understood as containing wet cement. The cement truck  200  is parked in proximity to the reclaim area  20  with the tumbler  210  oriented such that the reclaim gate  50  is in the lowest position on the tumbler  210 . Rinse water  160  is introduced into the tumbler  210  for washing and diluting the wet cement. With the wet cement diluted the constituent sand  140 , slurry  150 , and the rinse water  160  can pass through the reclaim gate  50  when the reclaim gate  50  is open and then into the reclaim area  20 . The aggregate  130  remains in the tumbler  210 . 
     The reclaim area  20  is beneficially a paved area having a downward slope that runs toward hay bales  30  arranged in a semi-enclosed pattern. A fence/reclamation structure  35  comprised of something like a synthetic geotextile material for filtering water in sediment control projects is draped over the inner periphery of the hay bales  30 . The hay bales  30  reinforce the fence/reclamation structure  35  while also providing another layer of filtration. The hay bales  30  may be arranged as depicted in  FIG. 1 , bounding three (3) sides of a rectangular area, or they may be placed in any arcuate or semi-circular configuration to suit a particular reclaim area  20 . The hay bales can be reinforced by blocks  40 . 
     The dislodged sand  140  and slurry  150  pools in the reclaim area  20 . The sand  140  will pool up and remain within the hay bale  30  and fence/reclamation structure  35  due to the reduction in the velocity of the flow of the slurry  150  and filtration. The slurry  150  continues to flow under, around, and through the hay bales  30  and the fence/reclamation structure  35  to eventually flow into a waste pit or another receiver. When only the aggregate  130  remains within the cleansed tumbler  210  the reclaim gate  50  can be closed by counter rotation of a turn plate  100 . The aggregate  130  can then be removed from the tumbler  210  for reuse. The sand  140 , having been filtered from the slurry  150  in the reclaim area  20  can also be reused. The rinse water  160  can also be reused after the slurry settles. 
     The hay bales  30  need not have any special make-up or special baled constituents. That is, almost any type of plant stem may be used. Known suitable bales include leguminous crops such as alfalfa or clover, or the use of typically inedible or unconventional plant stems such as Johnson grass or the straws of various cereal crops. As noted the hay bales  30  may be held in a preferred configuration by one (1) or more stabilizer blocks  40 . The stabilizer blocks  40  may be any type of concrete masonry unit which stabilizes the hay bales. 
     Referring now to  FIGS. 1 and 2 , the reclaim gate  50  can be added to an existing tumbler  210  of a ready-mix cement truck  200  or it can be part of a new truck. Either way the tumbler  210  would be prepared by cutting a circular tumbler aperture  215  at a location which enables the cement mixture to exit the tumbler  210 . The tumbler aperture  215  should have a diameter which fits a tumbler flange aperture  55  of a tumbler flange  60 . The tumbler flange  60  is an annular ring permanently attached to the tumbler  210 , preferably by being welded  62  concentrically around the tumbler aperture  215 . The tumbler flange  60  includes a plurality of threaded fastener apertures  65 . 
     Refer now to  FIG. 2  for an exploded view and to  FIG. 3  for a sectional view of the reclaim gate  50 . In the preferred embodiment the reclaim gate  50  includes a stacked assembly of circular planar members including the tumbler flange  60 , a strainer  70 , a fixed plate  80 , and the turn plate  100 . 
     The strainer  70  is located externally adjacent the tumbler flange  60 . The strainer  70  retains the aggregate  130  within the tumbler  210  while allowing sand  140 , slurry  150  and rinse water  160  to exit. The strainer  70  includes a plurality of equally-spaced strainer reclaim apertures  75  that are sized to limit exodus of the aggregate  130  while allowing the sand  140 , slurry  150  and rinse water  160  to pass through. The strainer  70  is preferably formed using a circular section of an expanded metal plate. The strainer  70  also includes a central strainer pivot aperture  77 . The central strainer pivot aperture  77  is large enough to receive a nut fastener  120  (see  FIG. 3 ). 
     The fixed plate  80  has a perimeter edge  113  which protrude perpendicularly toward the tumbler flange  60 , thereby forming an ‘L”-shaped cross-section perimeter. The “L”-shaped perimeter edge  113  encompasses and retains the circular strainer  70  in parallel between the fixed plate  80  and the tumbler flange  60 . The fixed plate  80  has a plurality of fixed plate reclaim apertures  85  for enabling the passage of the sand  140 , slurry  150  and rinse water  160  admixture. The fixed plate reclaim apertures  85  are beneficially arranged in a uniform circular pattern around the fixed plate  80 . The fixed plate  80  further includes a centrally located fixed plate pivot aperture  95  and a plurality of fastener apertures  65 . The fixed plate  80  is attached to the tumbler flange  60  using a plurality of threaded plate fasteners  90  that pass through the threaded fastener apertures  65 . 
     The turn plate  100  is rotatingly attached to the fixed plate  80  along a common center axis via an axle-like gate actuator  115 . The gate actuator  115  is a threaded  118  connector that passes through a turn plate pivot aperture  110  in the turn plate  100 , through the fixed plate pivot aperture  95  and into the central strainer pivot aperture  77  where it threads onto the nut fastener  120 . Beneficially the nut fastener  120  is distorted after receiving the gate actuator  115  such that the nut fastener  120  cannot vibrate or come off the gate actuator  115 . 
     The turn plate  100  has a plurality of turn plate reclaim apertures  105  that are sized and spaced to be able to match the locations and sizes of the fixed plate reclaim apertures  85 . A flow of sand  140 , slurry  150  and rinse water  160  from the tumbler  210  is enabled by rotating the turn plate  100  relative to the fixed plate  80  via the gate actuator  115  (described in more detail subsequently) so as to align the turn plate reclaim apertures  105  with the fixed plate reclaim apertures  85 . When aligned, the sand  140 , slurry  150  and rinse water  160  can exit the tumbler  210 . To prevent the sand  140  and slurry  150  from leaving the tumbler  210  the reclaim gate  50  can be closed by counter rotation of the turn plate  100  such that the fixed plate reclaim apertures  85  and turn plate reclaim apertures  105  are not aligned. 
     Referring now primarily to  FIG. 2 , as noted the fixed plate pivot aperture  95  and the turn plate pivot aperture  110  are joined together yet can turn relative to one another via the gate actuator  115 . To that end the turn plate pivot aperture  110  includes a keyway  112  along a perimeter edge. The gate actuator  115  is configured with a protruding key  117 . The gate actuator  115  is routed through the plate pivot aperture  110 , through the pivot aperture  95 , through the strainer pivot aperture  77  and into the nut fastener  120  such that the key  117  inserts into the keyway  112 . As the gate actuator  115  is turned it and the turn plate  100  rotate together. 
     In practice an actuator tool  125  is used to rotate the gate actuator  115 . The actuator tool  125  provides needed leverage and is preferably an open-end wrench appropriate to the size of a head on the gate actuator  115 . As the gate actuator  115  is turned using the actuator tool  125  the turn plate  100  is rotated. 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention; only one particular configuration is shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The method of installing the reclaim gate  50  may be achieved by performing the following: procuring the reclaim gate  50 ; determining a suitable location upon a cement truck tumbler  210  for the reclaim gate  50  so as to enable removal of the cement sand  140  and slurry  150  and rinse water  160 ; cutting a tumbler aperture  215  through the tumbler  210 ; aligning the tumbler flange  60  to the tumbler flange aperture  55 ; welding the tumbler flange  60  to the tumbler  210 ; pre-assembling the turn plate  100  and the fixed plate  80 , by inserting the gate actuator  115  through the turn plate pivot aperture  110  and the fixed plate pivot aperture  95 ; securing the turn plate  100  and fixed plate  80  together by installing and tightening the nut fastener  120  onto the threaded region  118  of the gate actuator  115 ; deforming the threaded region to prevent the nut fastener  120  from coming off; placing the strainer  70  into the recessed area of the fixed plate  80 ; and, mounting the turn plate  100 , fixed plate  80 , and strainer  70 , as an assembly, onto the tumbler flange  60  by inserting and tightening the plate fasteners  90 . The reclaim gate  50  is then ready for use. 
     The method  10  may be achieved by performing the following steps: parking a cement truck  200  proximity to a reclaim area  20 ; stopping the rotation of the tumbler  210  so as to orient the tumbler  210  at a suitable position for dispensing the constituents of the contained concrete mix; opening the tumbler  210  to allow the cement sand  140  and slurry  150  to pass through strainer openings that are too small to allow the aggregate  130  to pass; rinsing the contained cement with rinse water  160  to clean an interior portion of the tumbler  210  and to dilute the remaining cement mixture; allowing sand  140 , slurry  150 , and rinse water  160  to pass through the strainer openings and thus to flow from the tumbler  210 ; leaving the aggregate  130  in the tumbler  210 ; passing the sand  140 , slurry  150 , and rinse water  160  into the reclaim area  20 ; filtering the sand to remain in the reclaim area; passing the slurry  150  out of the reclaim area  20 , settling the slurry  150 , and recovering the aggregate  130 , sand  149 , and rinse water  160 . 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.