Abstract:
A form and process for casting concrete blocks, each having at least one side textured. The blocks are cast in cavities which have a resilient insert on at least one side for imparting texture to the blocks. After the cast blocks are cured, the form is inverted and placed on a support surface. At least the side having the resilient insert is moved laterally away from the block and the form is lifted to leave the block on the support surface. The textured side can release from the form despite deep grooves and crevices simulating natural stones.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Applicant claims priority to U.S. Provisional Patent Application Ser. No. 61/148,442 filed Jan. 30, 2009. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     TECHNICAL FIELD 
     The invention relates to a form and a process for casting concrete blocks, and more specifically to a form which can be used to cast concrete blocks with deep texture on one side or on opposite sides of the block. The form also may be used to cast concrete blocks having one or more vertical passages through the block. Further, the form may be designed for casting a single block or for simultaneously casting multiple blocks. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is directed to a form and a process for casting one or more concrete blocks each of which has either one side of the block textured or two opposite sides of the block textured. The form defines one or more cavities, each having a bottom and sides including the textured side or sides and an open top in which concrete is poured to cast the block. After the blocks have sufficiently cured, the form is then engaged with a machine which inverts the form and positions it above a support surface such as a pallet. The sides of the form which define the textured sides of the block or blocks are then moved apart by the machine to provide clearance for the block or blocks to release from the form and the form is lifted away from the support surface, leaving the finished blocks. The machine may be, for example, a forklift which has tines which engage slots in the form. The sides of the form are moved apart by increasing the spacing of the forklift tines. Alternately, a dedicated machine may be provided for inverting and positioning the form above the support surface, separating the form sides, lifting the form, returning the form back to an upright position for casting additional blocks. The form may include one or more members which form vertical passages and end grooves in the cast blocks. These members have sufficient relief to allow the blocks to easily release from the inverted form. 
     Various objects and advantages of the invention will become apparent from the following detailed description of the invention and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary perspective view of an exemplary section of a retaining which constructed from concrete blocks cast in the form of the present invention and according to the process of the present invention; 
         FIG. 2  is a top plan view of an exemplary block cast in a form and according to the process of the present invention; 
         FIG. 3  is a perspective view as seen from the upper front of a form according to the present invention in an upright closed position; and 
         FIG. 4  is a perspective view as seen from the upper front of the form of  FIG. 3  shown in an upright open position; 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of a fragmentary portion of a retaining wall  20  formed from a plurality of stacked blocks which are cast with highly textured faces  21  which simulate natural stones. A single block  22  may have a face  23  which simulates multiple stones, in this case four simulated stones  24 - 27  with deep grooves  28  between adjacent simulated stones  24 - 27 . If the wall  20  is a freestanding wall, opposite faces of the blocks may be textured so that both sides of the wall  20  will appear to be formed from stacked stones. 
       FIG. 2  is a top view showing an example of a block  30  which can be made using the form and process of the invention. However, it should be understood that this is merely one example and that other block configurations also may be made using the invention. The illustrated block  30  has two spaced faces  31 - 32  which are highly textured. Each of the faces  31 - 32  may have the appearance of a single natural stone or may have the appearance of multiple natural stones with deep grooves formed between the simulated stones as would appear with natural stones are stacked. The block  30  has a substantially flat top  33  and a substantially parallel flat bottom (not shown) which allows the block  30  to be stacked with other blocks for forming a vertical wall. The block  30  also has two spaced sides  34  and  35 . If a number of blocks  30  are to be used only for making straight walls, the sides  34  and  35  may be parallel to each other. However, if the sides  34  and  35  are tapered so that the width of the block face  31  is less than the width of the block face  32 , blocks  30  may be used for constructing both straight and curved walls. For straight walls, adjacent blocks are reversed so that adjacent block faces  31  and  32  alternate. If two short block faces  31  abut and two long block faces  32  abut on adjacent blocks, the adjacent blocks will have an angle which will allow the wall to curve or bend. In the exemplary block  30 , vertical semicircular grooves  36  extend the height of block sides  34  and  35  and a vertical center passage  37  extends the height of the block  30 . The grooves  36  and the center passage  37  have sufficient relief to allow easy separation of the block  30  from the form in which it was cast. The grooves  36  and one or more center passages  37  are optional. When provided, they lighten the weight of the block  30  and also allow interconnecting the blocks in adjacent tiers of a wall for increasing the integrity of a wall formed from the blocks  30 . 
       FIGS. 3 and 4  show a form  40  according to the invention. The form  40  has six cavities  41   a - 41   f  for simultaneously casting  6  of the blocks  30 . It will be understood that the form may be modified for casting only one block or for simultaneously casting a desired number of the blocks  30 . Further, the configurations of the cavities  41   a - 41   f  can be varied for providing a desired shape and size and surface texture to the cast blocks. As will be discussed below, the cavities  41   a - 41   f  include inserts and textured surfaces for shaping and texturing the cast blocks. The cavities  41   a - 41   c  extend in a row and the cavities  41   d - 41   f  extend in a row. The cavities  41   a - 41   f  may be configured to provide the same shape, surface design and texture to all of the blocks cast therein, or blocks cast in different cavities may have different shapes and surface designs. Further, blocks cast in two adjacent cavities may have different lengths. 
     The form  40  includes a rigid front plate  42 , a rigid rear plate  43 , a rigid center partition  44  which is secured to the front and rear plates  42 - 43 , and two side plates  45  and  46  which are mounted on a plurality of parallel tubes, channels or members  47  for movement towards and away from opposite sides of the center partition  44 . The parallel members  47  do not move relative to the center partition  44 . 
     A rigid base  48  extends continuously along the bottoms of the three cavities  41   a - 41   c  and a separate rigid base  49  extends continuously along the bottoms of the three cavities  41   d - 41   f . For the cavity  41   a , spaced members  50  and  51  form the angled block sides  34  and  35  and a member  52  forms the vertical center passage through the block  30 . For the cavity  41   b , the member  51  and a member  53  form the angled block sides  34  and  35  and a member  54  forms the vertical center passage  37  through the block  30 . For the cavity  41   c , the member  53  and a member  55  form the angled block sides  34  and  35  and a member  56  forms the vertical center passage  37  through the block  30 . The members  50 - 56  are secured to the rigid base  48 . For the cavity  41   d , spaced members  57  and  58  form the angled block sides  34  and  35  and a member  59  forms the vertical center passage through the block  30 . For the cavity  41   e , the member  58  and a member  60  form the angled block sides  34  and  35  and a member  61  forms the vertical center passage  37  through the block  30 . For the cavity  41   f , the member  60  and a member  62  form the angled block sides  34  and  35  and a member  63  forms the vertical center passage  37  through the block  30 . The members  57 - 62  are secured to the rigid base  49 . The members  50 - 62  may be formed from a rigid material or from a resilient material. 
     A resilient insert  64  is mounted on one side of the center partition  44 . The insert  64  is shaped to impart a desired design to one face of blocks cast in the cavities  41   a - 41   c . The opposite faces of blocks cast in the cavities  41   a - 41   c  are formed by a resilient insert  65  which is secured to the side plate  45  and a resilient insert  66  which is attached to the side plate  45 . The resilient inserts  64 - 67  may be textured, for example, to simulate the appearance of one or more stones on the face of a cast concrete block with deep crevices separating the simulated stones. Further, prior to casting concrete blocks in the form  40 , an optional dye may be applied to the shaped surfaces of the inserts  64 - 67  to impart the coloration of natural stones to the cast blocks. Alternately, coloring may be added to the concrete prior to casting the blocks. 
     According to the invention, two parallel channels  70 - 71  are mounted in spaced, aligned slots  72 - 73  in the front plate  42 , respectively, and in corresponding slots (not shown) in the rear plate  43 . The channels are sized to receive tines (not shown) on a forklift (not shown). The slots  72 - 73  are wider than the width of the channels so that the channels  70 - 71  may be moved between the positions shown in  FIG. 3  to the positions shown in  FIG. 4  where the channels  70 - 71  are spaced further apart. Similarly, ends  74  and  75 , respectively, of the cavity bases  48  and  49  are mounted for limited movement in slots  76  and  77 . The cavity bases  48  and  49  can move between the positions shown in  FIG. 3  to the positions shown in  FIG. 4  where they are spaced further apart. The form side place  45  is attached to the channel  70  so that when the channel  70  is moved to the position shown in  FIG. 4 , the side plate  45  and attached insert  65  are spaced further from the center partition  44  and the attached insert  64 . Similarly, the form side plate  46  is attached to the channel  71  so that when the channel  71  is moved to the position of  FIG. 4 , the side plate  46  and the attached insert  67  are spaced further from the center partition  44  and the attached insert  66 . The channels  70 - 71  are moved to the positions shown in  FIG. 4  by engaging the channels  70 - 71  with tines on a forklift and operating the forklift to move the tines apart. As the channels  70 - 71  are moved to the  FIG. 4  position, the bases  48  and  49  are simultaneously moved to the  FIG. 4  positions where they are spaced further from the inserts  64  and  66 , respectively. Moving the channels  70 - 71  to the  FIG. 4  positions provides sufficient clearances between blocks cast in the cavities  41   a - 41   c  and the inserts  64  and  65  to allow cast blocks to be removed from the cavities, and allows sufficient clearances between blocks cast in the cavities  41   d - 41   f  and the inserts  66  and  67  to allow cast blocks to be removed from the cavities. 
     Concrete blocks are cast using the form  40  according to the following process:
         a) the form  40  is moved to a pouring location either using a forklift or a conveyor and the cavities  41   a - 41   f  are filled with concrete;   b) the form  40  may be left at the pouring location or it may be moved on a conveyor or with a forklift to a location while the poured concrete blocks sufficiently cure to permit removal of the blocks from the form  40 ; and   c) the blocks are then removed from the form  40  by inverting the form  40 , positioning the form on a support surface, moving the channels  70 - 71  apart to open the form  40 , and then lifting the form  40 , leaving the blocks on the support surface.       

     The support surface on which the blocks are deposited may be, for example, a conveyor or a pallet or a layer of blocks which were previously deposited on a pallet. Alternately, the cured blocks could be stacked on the bed of a delivery vehicle. 
     The process has been described as using a forklift for moving the form after the blocks are cast and for inverting the form, positioning the form on a support surface, opening the form and for lifting the form to leave the blocks on the support surface. It should be appreciated that this can be performed by one or more dedicated machines which move, invert and open the form. Further, a number of the forms may be stacked while the cast blocks cure, either using a forklift or another machine 
     It will be appreciated that various modifications and changes may be made to the above described preferred embodiment of a form and process for casting concrete blocks without departing from the scope of the following claims.