Abstract:
An apparatus and process for the manufacture of brick block, i.e. a concrete chimney or wall block, with an impressed brick grout pattern on the face thereof, comprises a mold adapted to fit a known concrete block manufacturing machine. The mold has grout bars to impress a simulated laid brick pattern onto at least one vertical face of the block, the grout bar moveable in and out from a wall of the mold by hydraulic components. The hydraulic components utilize a unique multi-piston hydraulic block.

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of application Ser. No. 08/988,277 filed Dec. 10, 1997, now abandoned, having the same title and the same inventor. 
    
    
     The present invention is a brick block and process and apparatus for its manufacture. This invention is particularly useful for manufacturing chimney block having a brick pattern of preferably three courses impressed on all four vertical sides as well as for manufacturing wall block which may have a brick pattern on one, two or three sides. 
     THIS INVENTION 
     The brick block of this invention comprises a rectangular block of monolithic concrete colored throughout to imitate the color of brick. At least one vertical face of the rectangular block is horizontally and vertically grooved to create a pattern simulating laid brick. The grout lines contain a coloring agent (e.g. a pigmented latex) that simulates the color of a mortared joint. The brick block may be a chimney block, all four vertical sides of which have the impressed brick pattern. It may also be a wall block having two cores and having one to two sides faces with the brick pattern or if it be an end wall block having three sides of the block with the pattern. 
     By the term “brick block” is meant a molded monolithic concrete block colored throughout to simulate a natural brick color one vertical face of which has an impressed brick grout pattern simulating laid brick, one, two, and preferably at least three or more courses high. 
     The apparatus for the manufacture of the brick block comprises a mold having four vertical walls the interior of which has the dimensions of the desired brick block. One or more of the walls has means for impressing the grout pattern on the face of the brick block as it is molded. This means includes a hydraulic system that moves a grout bar outwardly into the concrete mass as it is being formed approximately ⅛ inch or so and after it is formed and before the block is ejected from the mold retracts the grout bar to be flush with the mold face. 
     The block has a core as is usual in the manufacture of conventional wall and chimney block. The concrete mixture has zero slump so that the impressed grout pattern is retained in the block as it is ejected from the mold. The concrete mixture has an increased moisture content while maintaining zero slump to produce on the “brick” face of the block, a brick-like surface. This results in the block having a higher density as compared to that of conventional wall block. The density is usually above 100 pounds per cubic foot, e.g. 103 pounds per cubic foot. 
     Ejection is accomplished by having a head or ram descend from the top of the mold around the core to push the block downwardly onto a platen which is then moved out from underneath the mold and set off for curing of the concrete mass. 
     The hydraulic mechanism that extends and retracts the grout bar has two or more hydraulic cylinders attached to the bar so that the grout bar remains square with the face of the mold. 
     The mold of the present invention is adapted to fit in or onto a conventional block manufacturing machine such as the “Bescopac” manufactured by Besser, 81 Johnson Street, Alpena, Mich. 49707. Because of the hydraulic mechanism required to impress the grout pattern, the mold is oversized or larger than that used for a standard block and some slight modification has to be made to the machine to receive the frame holding the present mold, namely, the width of the rubber dam is decreased. 
     Once the mold is in place, manufacture is quite straightforward. A charge of concrete, pre-colored throughout, is pushed into the mold cavity around a core or cores held in place by overhead hangers. As is conventional, the concrete is caused to settle in place by vibration during which time the grout bar is extended into the cement mixture and then is retracted after vibration has ceased. Following this, a head or ram descends into the mold to push the block out of the mold onto the platen on which it is removed. The core may be vented to prevent any vacuum forming which would distort the block. After the block has been allowed to cure, the grout lines of the brick pattern are painted as with a masonry slur or a pigmented latex the color of mortar. 
     The cycle time per brick block is 12 to 15 seconds. During a six-hour operating period, 1100 brick block have been made using one operator. 
    
    
     THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a prospective view of the component parts of the molding process showing their relative arrangement; 
     FIG. 2 is a plan view of a mold to impress a brick pattern on all four sides of a chimney block, 
     FIG. 3 is an enlarged view of the mold wall, circled by circle  3  in FIG. 2, in part broken away to show interior detail of the hydraulic block; 
     FIG. 4 is an enlarged view of that portion of the hydraulic block, circled by circle  4  in FIG. 3., showing one of the hydraulic pistons; 
     FIG. 5 is a prospective view of the mold of FIG. 2 showing in particular the face plates and the grout bars in their extended positions. The hydraulic lines are not shown in FIG. 5, nor on the frame  50  as illustrated in FIG. 1; 
     FIG. 6 is an exploded prospective view showing one hydraulic block/grout bar/face plate assembly; 
     FIG. 7 is a plan view of a hydraulic block without its top plate, broken away to show the passageways for hydraulic fluid; 
     FIG. 8 is a section side view of the hydraulic block of FIG. 7 taken along line  8 — 8  thereof; 
     FIG. 9 is another section side view of the block taken along line  9 — 9  of FIG. 7; 
     FIG. 10 is a prospective view of the frame that holds the mold and that fits into the vibrating mechanism of the block molding machine; 
     FIG. 11 is a prospective view of the core assembly; 
     FIG. 12 is a prospective view of the head assembly used to push the completed block from the mold and; 
     FIG. 13 is a prospective view of the underside of the head plate of the head assembly. 
    
    
     In the drawings, the same part has the same number throughout. 
     DESCRIPTION 
     In FIG. 1 the head assembly is generally indicated at  20 , the core assembly at  30 , and the mold assembly at  50 . A completed brick block is shown at  40  resting on a pallet  41  to be removed to curing and grout line coloring. 
     Referring to FIG. 11, the core assembly,  30  fits onto the top of mold  50  and consists of a plate or tray  31  bounded on three sides by vertical walks  32 ,  33  and  34 . Plate  31  has a rectangular opening  35  that mates with and allows the head plate  21  to pass through. A core  36  is suspended beneath plate  31  by means of vertical ribs  37  and  38  welded to both the core  36  and plate  31 . Bolts  39  secure the core assembly to the mold frame. The core assembly shown is for the manufacture of chimney block having a single core. If wall block is to be manufactured, two cores are customary. In operation, the charge of concrete is placed in the mold by pushing it onto plate  31  from the open side into opening  35 . 
     Turning to FIGS. 12 and 13, head assembly  20  consists of head plate generally designated by  21 , and a metal box or head  22  to which the head plate is bolted by bolts  23 . An adapter plate  25  is bolted or welded onto the top of head  22 . Adapter place  25  is designed to bolt onto the head mechanism of the block manufacturing machine. 
     The replaceable head plate, FIG. 13, typically consists of  4  sections  26 ,  27 ,  28  and  29  bolted to the bottom of head  22  by means of recessed bolts  23 . As can be seen the sections  26 ,  27 ,  28  and  29  are spaced apart to match with the slots  42  of the head which permit the head to descend past ribs  37  and  38  of the core assembly about the core  36  to eject the molded brick block  40 . 
     The mold frame  60  is shown in FIG.  10 . It is a heavy metal box having walls  61 ,  62 ,  63  and  64  and flanges  65 ,  66 ,  67  and  68 . The flanges are bored to be bolted to the vibrator of the block molding machine. The walls and flanges are recessed as at  69  to accommodate hydraulic lines. The walls as illustrated by walls  62  and  64  are drilled with numerous openings to accommodate the fitting of a hydraulic block on the outside and the grout bars and face plates on the inside as more fully shown in FIG.  6 . Frame  60  is subjected to extremely severe punishment in service. Earlier designs failed by work hardening, stress cracking and corner breakage. For this reason walls  61  and  63  overlap their respective flanges are securely bolted to walls  62  and  64  as well as the flanges. The joints can be further strengthened by welding. Also, all holes on the frame are kept as small as possible and openings with corners such as rectangles are not used to avoid points of stress concentration. 
     In FIG. 6, the hydraulic block is shown at  72 / 73  and its top or retaining plate at  79 . Both are attached to wall  64  of the frame by bolts not shown, although the bolt holes are. The grout bar frame  81  with the grout bars  82  are on the other side of the wall. The grout bars  82  are secured to frame  81  by countersunk bolts  88 , only one of which is shown. Bolts  88  extend through holes threaded in the grout bars to be flush with the faces of the grout bars. Numerous spacers  83  extend through and around the grout bar frame. These hold the face plates  84  by means of a series of counter sunk bolts, two of which are shown at  86 , extending through wall  64  and spacers  83  to seat in face plates  84  in threaded openings  85 . 
     It is a feature of this invention to provide for a slight tapering of the face plates, i.e. to allow a draft, by sizing spacers  83  such that each tier of spacers become shorter, top to bottom. The bottom most face plates  84  are set back {fraction (1/32)} to {fraction (3/32)} inches, e.g. {fraction (1/16)} inch, further than the top ones for the three course pattern illustrated. This facilitates ejection of the brick block from the mold. 
     The moveable grout bar frame  81  and bars  82 , are attached to the hydraulic piston  72  of the hydraulic block  72 / 73  by means of bolts  87 . The grout bars  82  are sized to fit tightly between the face plates  84  to prevent leakage of cement. If leakage does occur it can flow around the bars and drop out of the mold because when the grout bar is fully retracted a small clearance between it and wall  64  is provided to allow for the drainage. The grout bars  82  and face plates  84  are made of case hardened tool steel to resist wear. The hydraulic block exerts a very high pressure on the grout bar, in the order of 1800 psi or greater, such that any of the concrete mixture caught in the interstices is pulverized and flows out of the mold. Because two or more hydraulic cylinders are used towards the ends of the grout bar frame  81 , the frame is pushed up against the face plates and levels thereagainst so that the grout bars are square with the faces when extended. 
     When retracted, the faces of grout bars  82  are flush with the faces of face plates  84 . When extended, they extend {fraction (1/16)} to ½ inch beyond the face plates, e.g. ⅛ inch, dimension “x” of FIG.  3 . If the grout bars are not fully retracted to be flush with the face plates they will ruin the surface texture of the brick block during ejection. 
     As shown, the ends of grout bar frame  81  extends a grout bar thickness on either side beyond the ends of grout bars  82  to mate with the grout bars on either side. In a four-sided mold only two opposing frames have these extensions. Note the corners designated by “ 89 ” in FIG.  2 . 
     The hydraulic block  71  is shown in FIGS. 7,  8  and  9 . It is designed to provide dual action positive extension and extraction. It consists of two blocks of aluminum  72  and  73 , side by side, into which are bored four chambers, two in each,  74  to receive hydraulic pistons. Chambers  74  have steel liners  75 . Hydraulic passageways connect the chambers, passageways  76  for incoming pressure and passageways  77  for reverse pressure. Openings threaded to take hydraulic fittings connect the passageways, opening  91  for passageways  76  and opening  92  for passageways  77 . Blocks  72  and  73  all held together by bolts  93  and  94 , in addition to being bolted to the frame. O-ring seals  95  are provided to seal the joints of the passageways. 
     In FIG. 4, the one of the hydraulic pistons is shown in greater detail. A hydraulic piston  101  having two spaced apart shoulders or piston rings,  102  and  103 , fits within liners  75 . An O-ring seal  104  is carried between shoulders  102  and  103 . A metal end cap  105  with O-ring seals  106  and  107  holds piston  101  and end cap  105  in turn is held by retaining plate  79  when the assembly is bolted to frame wall  64 . Another O-ring seal  108  is provided between retaining plate  79  and wall  64 . Item  109  is a bolt head of one of the bolts tying the assembly to the frame. Item  110  is simply a light metal shield used to protect the hydraulic lines. 
     Note that the top and bottom surface areas of the piston subject to the hydraulic pressures are not equal. The cyclic hydraulic pressures applied to each passageway are, however, applied in a known manner to assure positive extension and traction of the piston and can be as high as 1800 to 2400 psi. 
     Finally, the assembly of the mold is shown in FIGS. 2,  3  and  5 . In FIG. 5 the hydraulic lines are not shown. In FIG. 3 the piston in block  73  is the same as that in block  72  and will not be further described. 
     Hydraulic lines  114  and  115  encircle the mold, resting in cutouts  69  and being protected by metal shields  110 ,  111 ,  112  and  113  bolted to the frame. The hydraulic lines are connected by suitable fittings to each hydraulic block, fitting  116  to connect to part  91  and fitting  117  to connect to part  92  for block  72 / 73 . Similarly the hydraulic lines are connected to hydraulic blocks  123 ,  121  and  122  on the other three sides of the mold. Hydraulic fluid is supplied to line  114  via fitting  119  and to line  115  by fitting  118 . 
     The brick block molding apparatus operation is as follows: 
     A pre-sized or weighted concrete charge is pushed onto the core tray assembly  30  where it falls into opening  35  and in and around core  36 . The block machine is vibrating frame  50  and the mold at this time. The mold bottom is closed by a pallet  41  being pressed up thereagainst. As the mold is being filled, the hydraulic mechanism holds the grout bards  82  extended about ⅛ inch into the mold. After the charge is in the mold and settled, vibration is stopped and the grout bars are retracted to be flush with face plates  84 . Thereafter head  20  descends into the mold contacting the formed block and pushing it downwardly onto pallet  40 , which is descending at the same rate as head  20 . Core  36  has a spring loaded vent (not shown) as is known so that a vacuum is not formed therein which would distort the tender block. 
     After the finished block, a chimney block  40  in this example, clears the mold it and pallet  40  are removed and set aside to allow curing following which the grout lines are striped with a cement colored paint such as a pigmented latex. Another pallet is put into place, head  20  is retracted and the cycle is repeated. It is a preferred feature to angle the inside corners of the block at 45 degrees as shown rather than round them as this facilitates ejection and yields a stronger block. In a series of 20 or more blocks, the variation of any dimension of a block will be less than 2 percent of the average of that dimension. 
     It is obvious that by the above described method, blocks can be produced having an impressed brick pattern on one, two, three or all four sides as may be desired. All that is required is for the mechanisms shown in FIG. 6 to be replicated on each side where a brick pattern is desired. 
     The brick block apparatus of this invention uses a single hydraulic power service. The manifold/hydraulic block assembly illustrated needs only 10 fittings (for a four sided mold) to connect the lines and blocks. An earlier design required 100 fittings or so which greatly increased the opportunity for leakage and breakage. 
     It is a feature of this invention to use a concrete charge to the mold that is uniformly colored throughout to produce a face having a natural brick color. The concrete is formulated to 0 slump and has a high density. 
     The brick block product has an authentic brick appearance and is a cost efficient alternative to laying up courses of brick by hand. It is faster and easier to install and gives a better appearance when laying up wall. 
     Having described this invention, what is sought to be protected by Letters Patent is succinctly set forth in the following claims.