The present disclosure concerns embodiments of an apparatus and method for making a wall block, such as for constructing retaining walls or fences.
Masonry products, such as blocks or bricks for constructing walls, have been made for many years by various molding processes. It is common to split off a portion of a cured block, such as with a splitting machine or a hammer and chisel, so as to create a decorative face on a surface of the block that resembles the surface texture of natural stone. The face created by the splitting process is often referred to in the industry as “split face” or “rock face.” Blocks formed with a split face are highly appealing for constructing retaining walls and fences. The splitting of cured blocks, however, involves additional equipment and manufacturing steps and results in material wastage.
In order to avoid the shortcomings of conventional splitting processes, a number of techniques have been developed to achieve the same “split face” texture without additional splitting steps. For example, U.S. Pat. No. 7,100,866 to Hammer et al. discloses a mold having a series of inwardly extending projections that contact an adjacent surface of an uncured block in the mold. As the uncured block is stripped from the mold, the projections create a roughened or irregular surface texture on the adjacent block surface resembling a “split face.”
It is also desirable to create an “ashlar” or random pattern in the exposed face of a retaining wall or fence to provide the appearance of a wall made from natural stone blocks. Various block systems have been proposed to create an ashlar pattern in a wall. These block systems typically comprise multiple blocks of different sizes that can be randomly stacked together in a wall. Another technique used to form an ashlar pattern involves stamping or molding into the surface of an uncured block a pattern that resembles the faces of multiple, differently sized blocks. This allows construction of a wall having an ashlar pattern using multiple blocks of the same size and shape.
According to one aspect, the present disclosure concerns embodiments of an apparatus and method for making a wall block, such as for constructing retaining walls or fences, that has at least one surface formed with a pattern resembling the faces of multiple blocks. In particular embodiments, the surface of the wall block has a plurality of discrete surface portions that are separated by one or more elongated recessed surface portions or scores such that each surface portion resembles the face of a separate block. The surface portions can be provided with roughened surface textures resembling the surface of a split block, which can be formed by roughening or texturing the uncured block as it is removed from a mold.
According to one representative embodiment, an apparatus for molding and forming a roughened surface texture on at least one surface of an uncured masonry block, comprises a mold defining at least one mold cavity, a first opening through which block-forming material is introduced into the mold cavity, and a second opening through which a formed, uncured block may be removed from the mold cavity. The mold further comprises at least one wall having a plurality of projections extending into the mold cavity and contacting an adjacent surface of the uncured block, such that when the uncured block is removed from the mold cavity, the projections create a roughened surface texture on at least two surface portions of the adjacent surface, the at least two surface portions being separated by a recessed surface portion in the adjacent surface to give the appearance of two separate block faces in the adjacent surface.
According to another representative embodiment, an apparatus for molding and forming a roughened surface texture on at least one surface of an uncured masonry block, comprises a mold defining at least one mold cavity, in which an uncured block can be formed. The mold has an inner surface that forms an elongated notch in at least one surface of the uncured block to define first and second surface portions on opposite sides of the notch. The inner surface comprises a plurality of block-texturing members that form a roughened surface texture on the first and second surface portions when the block-texturing members are moved across the first and second surface portions upon removal of the uncured block from the mold.
According to another representative embodiment, a method for forming a masonry block, comprises introducing block-forming material into a mold cavity of a mold, the mold having a plurality of projections extending into the mold cavity and located between the top and bottom of the mold cavity. The method further includes forming an uncured block in the mold cavity, the uncured block having at least one surface on which there is formed at least one elongated recessed surface portion separating the at least one surface into first and second surface portions, and removing the uncured block from the mold cavity to move the projections across the at least one surface of the uncured block to produce a roughened texture on the first and second surface portions so as to give the appearance of two split block faces on the at least one surface of the uncured block.
According to yet another representative embodiment, a method for forming a masonry block using a mold comprising a plurality of walls, a first opening, and a second opening opposite the first opening is provided. The method comprises introducing block-forming material into the mold via the first opening to form an uncured block having at least one surface on which there is formed at least one elongated notch separating the at least one surface into first and second surface portions, and removing the uncured block from the mold through the second opening, wherein the act of removing the uncured block from the mold creates a roughened texture on the first and second surface portions to provide the appearance of two separate split block faces on the at least one surface of the uncured block.
According to another representative embodiment, a method for forming a masonry block comprises placing a core bar in a mold, the core bar having a plurality of projections formed thereon, forming an uncured block in a mold, and moving the core bar relative to the uncured block to create a roughened surface texture on a surface portion of the uncured block contacting the projections of the core bar.
According to yet another representative embodiment, a core bar comprises an elongated body having plurality of projections configured to create a roughened surface texture on a surface of an uncured masonry block as the projections are moved across the surface of the uncured block.
The foregoing and other features and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
As used herein, the singular forms “a,” “an,” and “the” refer to one or more than one, unless the context clearly dictates otherwise.
As used herein, the term “includes” means “comprises.” For example, a device that includes or comprises A and B contains A and B but may optionally contain C or other components other than A and B. A device that includes or comprises A or B may contain A or B or A and B, and optionally one or more other components such as C.
As used herein, the term “ashlar pattern” refers to a pattern of differently sized block faces in the exposed surface of a wall or other structure constructed from multiple masonry blocks. The embodiments disclosed herein can be adapted to produce an ashlar pattern in at least one surface of a single block, so as to give the appearance of multiple block faces of different sizes.
As used herein, the term “masonry block” refers generally to any block that can be laid or stacked with other blocks to form a structure, such as a wall, steps, or a structure providing a horizontal upper surface (e.g., a walkway or patio). A masonry block can have any geometric shape, including but not limited to a square, rectangle, trapezoid, diamond, or combinations thereof. The structures formed by masonry blocks need not utilize mortar to join adjacent blocks.
According to one aspect, the present disclosure concerns embodiments of an apparatus and method for making a masonry block having two or more roughened surface portions on the same surface of the block to provide the block the appearance of two or more split faces of multiple blocks. In particular embodiments, the roughened surface portions are different sizes to create a random, or ashlar, pattern on one surface of the block. The embodiments described herein can be adapted to produce various types of masonry blocks, such as decorative architectural blocks, paving stones, landscaping blocks, retaining wall blocks, blocks for constructing fences or free-standing walls, steps, or walkways, and the like.
In the illustrated embodiment, each of the first and second faces 12, 14 can be formed with first, second, and third surface portions 24, 26, and 28, respectively, a vertically extending recessed portion, or elongated notch, 30 separating the first and second surface portions 24, 26, and a horizontally extending recessed portion, or elongated notch, 32 separating the third surface portion 28 from the first and second surface portions 24, 26. The horizontal recessed portion 32 extends from one side surface 20 to the other side surface 22 so as to bisect the block face into upper and lower surface portions. The vertical recessed portion 30 extends from the top surface 16 and intersects the horizontal recessed portion 32 to separate the upper surface portion into the first and second surface portions 24, 26. By virtue of the recessed portions 30, 32 separating the faces 12, 14 into three distinct surface portions, each face 12, 14 appears to be formed from the block faces of three separate blocks. As shown, the surface portions 24, 26, 28 desirably are of different sizes to provide a random or ashlar pattern in each face of the block.
Each face 12, 14 of the block also can be formed with recessed portions, or notches or scores, 40 extending between the top and bottom surfaces 16, 18 on each side of the respective face, and formed with a recessed portion, or notch, 42 extending between the sides surfaces 20, 22 adjacent the top surface 16. When like blocks 10 are stacked side-by-side and on top of each other in multiple courses to form a wall, the recessed portion 40 of one block abuts against the recessed portion 40 of an adjacent block in the same course to form a generally U-shaped, vertically extending groove separating the face 12, 14 of one block from the face 12, 14 of the other block. For example, if blocks are laid side-by-side such that the side surface 22 of each block abuts against the side surface 20 of an adjacent block, the recessed portions 40 at the juncture of two adjacent blocks separate surface portions 26, 28 of one block from the surface portions 24, 28 of the adjacent block. Similarly, the horizontally extending groove 42 of a first block 10 in a wall separates and extends between the surface portions 24, 26 of the first block and the surface portion 28 of a second block stacked directly on top of the first block.
While the block 10 in illustrated embodiment is formed with three surface portions on each face of the block, the block can have any number of surface portions on one or both faces of the block. For example, a block face 12, 14 can be formed with only one recessed portion extending horizontally across the block face to separate the block face into an upper surface portion and a lower portion, or with only one recessed portion extending vertically across the block face to separate the block face into left and right surface portions. As another example, a block face can be formed with multiple horizontal and/or vertical recessed portions to separate the block face into any number of surface portions. In addition, a surface portion can be the same size as or a different size than another surface portion in the same block face. For example, the vertical recessed portion 30 (
As shown, the surface portions 24, 26, 28 desirably have a roughened surface texture resembling a split block. In particular embodiments, the roughened surface texture is formed on the surface portions as the uncured block is removed from a mold, as described in detail below. The block 10 can be formed in a mold that is adapted to form one block at a time or a mold that is adapted to form multiple blocks in single block-forming cycle.
As best shown in
The mold 50 may be adapted for use with any conventional block-forming machine, such as those available from Columbia Machine (Vancouver, Wash.), Masa-USA, LLC (Green Bay, Wis.), Knauer Engineering (Germany), Besser, Inc. (Alpena, Mich.), Tiger Machine (Japan), or Hess Machinery (Ontario, Canada), to name a few.
A substantially horizontally disposed shoe, or plate, 90 (commonly referred to as a “mold head”) may be provided above each mold cavity to facilitate compression of the block-forming material during the block forming process and removal of the formed, uncured blocks 10 from the mold cavities. The shoes 90, each of which is shaped so as to be able to fit slidably within a respective mold cavity, is operable for movement between a raised position above the mold 50 (
Forms or core bars (not shown) for forming the cores 34, 36 and the channel 38 in each block can be inserted into the mold cavities. The forms can be supported by bars (not shown) that extend transversely across the open top of the mold 50 and are supported by the side walls 56, 58 of the mold, as known in the art.
The shape of the mold cavities define the plan shape and size of the blocks 10 (i.e., the shape and size of the block when viewed from above or below), with the vertical walls of the mold forming the vertical surfaces (the first and second faces 12, 14 and side surfaces 20, 22) of the blocks 10. The bottom and top surfaces of the blocks 10 can be formed by the upper surface of the pallet 92 and the lower surfaces of the shoes 90, respectively.
The end walls 52, 54, and the internal walls 60-74, each have interior surfaces configured to texture adjacent surfaces of the uncured blocks 10 as they are removed from their respective mold cavities, as explained in greater detail below. Each mold cavity in the configuration shown has a generally rectangular plan shape to provide a block having the same shape. However, the shape of each mold cavity can be varied to provide blocks having other geometrical plan shapes. For example, one or more of the walls defining a mold cavity can be configured to intersect an adjacent wall at an angle that is greater than or less than 90 degrees. In addition, one or more of the walls of a mold cavity may be curved or rounded. Alternatively, a wall may comprise plural segments interconnected to each other at angles. Moreover, a mold cavity may have greater than or less than four vertical walls.
The wall 52 in the illustrated configuration comprises a body 100 having a first major surface 102, which serves as an interior surface of the mold cavity 76, and second major surface 104. As used herein, the “major surfaces” of the mold wall refer to largest surfaces of the wall (the surfaces of the wall with the largest surface areas). A plurality of abutting block-texturing members, or projections, 106 extend outwardly from the first surface 102. As shown in
As shown in
Desirably, the projections 106 are distributed uniformly throughout the surface area of the first major surface 102 except at side portions 148, 150. As best shown in
As shown in
In the illustrated embodiment, the side surfaces 112, 114 of the projections 106 have slopes that are less than the slopes of the side surfaces 116, 118. This minimizes the likelihood of block-forming material being retained in the spaces between adjacent projections as the block 10 is being removed from the mold cavity 76. In an alternative embodiment, the side surfaces 112, 114, 116, 118 of each projection can be oriented at the same angle with respect to the interior surface of the wall.
The elongated bars 120, 122 project into the mold cavity to form the recessed surface portions 32, 30 (
In particular embodiments, the horizontal bar 120 is adapted to be removed from the mold cavity 76 before the uncured block 10 is removed therefrom. In this regard, the first major surface 102 of the wall 52 can be formed with an elongated notch 132 (
As best shown in
As shown in
Similarly, another lip, or screed, 146 can be provided below the projections of the first and second sets of projections 124, 126. As shown in
In particular embodiments, the diagonal rows of projections 106 extend at angles less than or greater than 45 degrees with respect to the upper and lower edges of the mold wall. As shown in
In an exemplary embodiment, the rows extending upwardly left to right, such as row 140, are oriented at an angle θ of about 60 degrees with respect to the wall upper edge, and the rows extending upwardly right to left, such as row 142, form an angle ω of about 30 degrees with respect the wall upper edge. In an alternative embodiment, the angles θ and ω are 45 degrees, in which case crests 110 of the projections are vertically aligned from the upper edge to the lower edge of the wall, as disclosed in U.S. Pat. No. 7,100,886, which is incorporated herein by reference.
Although each mold cavity of the illustrated mold 50 is shown as having two walls for texturing opposed surfaces of each block 10, in other embodiments, only one such wall may be used for each mold cavity, or alternatively, two adjacent such walls may be used, or more than two walls for texturing the surfaces of a block may be used. For example, selected portions of the side walls 56, 58 can have projections for texturing one or both side surfaces 20, 22 of one or more blocks 10.
In addition, a wall of the mold can be provided with plural bars 120 and/or plural bars 122 to form any number of roughened surface portions separated by recessed portions in a face 12, 14 of the block 10. Moreover, a wall can be provided with only horizontal bar(s) 120 or with only vertical bar(s) 122. If a wall does not have any horizontal bars 120, all of the projections 106 on the wall can extend into the mold cavity the same distance (i.e., the sets of projections are not offset from each other) because stripping the block from the mold in this instance would not obliterate the recessed portions formed by the vertical bar(s) 122.
In the embodiment of
In one specific implementation, the projections 106 are machined in a piece of material (e.g., steel) to a depth of about ¼ inch. The width of each projection is about 0.87 inch at their respective bases 108 and about 0.19 inch at their respective end surfaces 110. The end surfaces 110 of the projections 106 of the first and second sets 124, 126 are offset from the end surfaces of the projections 106 of the third set 128 by a distance of about 1/16 inch to about ⅛ inch. Of course, these specific dimensions (as well as other dimensions provided in the present specification) are given to illustrate the invention and not to limit it. The dimensions provided herein can be modified as needed in different applications or situations.
In other embodiments, the projections 106 and/or the vertical bar 122 may be separately formed and then coupled or otherwise mounted to the mold wall, such as by welding or with conventional releasable fasteners (e.g., bolts). If releasable fasteners are used, the bar and/or the projections can be removed and replaced with new components when the existing components become worn or otherwise deviate from desired tolerances.
In the illustrated embodiment, as shown in
In still other embodiments, any of the walls 52, 54, 60, 62, 64, 66, 68, 70, 72, 74 can be used as “inserts” for an existing mold wall. For example, an insert having the same configuration as end wall 52 can be placed in the mold cavity 76 against the inner surface of an existing end wall of the mold. When used in this manner, the inserts can be secured to the interior surfaces of existing walls of a mold using suitable techniques or mechanisms, such as using bolts or by welding the inserts in place.
Explaining the operation of the mold, according to one specific approach, and referring initially to
The mold 50, or the pallet 92, or a combination of both may be vibrated for suitable period of time to assist in the loading of the mold 50 with fill material. The shoes 92 are then lowered into the mold cavities 76, 78, 80, 82, 84, against the top of the mass of fill material in each cavity. The shoes 92 desirably are sized so as to provide a slight clearance with the projections 106 when lowered into the mold cavities. Additional vibration, together with the pressure exerted by the shoes acts to densify the fill material and form the final shape of the blocks 10.
After the blocks 10 are formed, the horizontal bars 120 are removed from the mold via openings 130 (
More specifically, the projections 106 of the first, second, and third sets of projections 124, 126, and 128 of a mold wall (
Advantageously, unlike some prior art devices, the mold does not require concrete fill material to be retained on the inner surfaces of the mold walls for the purpose of creating roughened surfaces on the block. As such, the mold does not require frequent stoppages in production to clear material from the walls of the mold. Other techniques also can be used to minimize the retention of concrete on the inner surfaces of the mold, for example, a concrete release agent can be applied to the inner surfaces of the mold, wire brushes can be mounted to shoes 90 and positioned to sweep or brush the inner surfaces of the mold walls as the blocks are stripped from the mold, and/or compressed gas nozzles can be positioned to directed compressed gas (e.g., compressed air) against the inner surfaces of the mold after the blocks are removed from the mold to blow away excess concrete from the inner surfaces of the mold.
Because the amount of fill material, if any, retained on projections 106 is minimal, the blocks 10 produced by the mold can maintain their dimensional tolerances through multiple cycles. Thus, in the illustrated example, the roughened surfaces 24, 26, 28 of the block 10 are substantially perpendicular to the top and bottom of the block. Also, the portion of the block from the bottom 18 to the recessed portion 32 (the lower half of the block) exhibits a substantially constant first cross-sectional profile and the portion of the block from the recessed portion 32 to the top 16 of the block (the upper half of the block) exhibits a substantially constant second cross-sectional profile that is slightly smaller in width than the first cross-sectional profile (see
The mold filling time, the vibration times and the amount of pressure exerted by the shoes 90 are determined by the particular block-forming machine being used, and the particular application. After the blocks are removed from the mold 50, they may be transported to a suitable curing station, where they can be cured using any suitable curing technique, such as, air curing, autoclaving, steam curing, or mist curing.
In alternative embodiments, the bar 120 can extend diagonally across the surface of a wall (in a direction that is non-parallel to the upper and lower edges of the wall) to form a non-horizontal or diagonally extending recessed portion on the face 12, 14 of the block 10. As can be appreciated, this would form roughened surface portions 24, 26, 28 having non-parallel sides. In this alternative embodiment, the bar 120 can be removed from the mold through an opening 130 in a side wall in a direction that is non-perpendicular and non-parallel to the direction of the mold upon removal of the block (the direction of arrow A in
In another implementation, a mold wall (e.g., wall 52) can be without any bars 120, 122 and instead can be formed with flat surface portions separating the sets of projections 124, 126, 128 so as to form generally smooth, non-roughened surface portions extending between and separating the roughened surface portions 24, 26, 28 in the face 12, 14 of the block 10. In another implementation, the first and second sets of projections 124, 126 can be offset from the third set of projections 128 as shown in
In this embodiment, each of the first and second faces 204, 206 can be formed with first and second roughened surface portions 222 and 224, a vertically extending, V-shaped recessed portion, or elongated notch, 226 separating the first and second surface portions 222, 224. The recessed portion 226 extends from the top surface 208 to the bottom surface 210 of the block. Each face 204, 206 also can be formed with two angled recessed portions 232 extending between the top surface 208 and the bottom surface 210 on opposite sides of the respective face at the side surfaces 212, 214 of the block. The recessed portions 226, 232 can have roughened surface textures similar to surface portions 222, 224.
In the embodiment shown in
As noted above, the recessed portions 226, 232 of the block also can be provided with a roughened surface texture (as shown in
As shown in
As best shown in
The projections 260 can be machined or otherwise formed in the sides of the core bar 240 such that each projection forms a portion of a frusto-pyramid. For example, as best shown in
In alternative embodiments, however, each side of the core bar can be formed with fully formed frusto-pyramids. In addition, other tapered or non-tapered shapes may be used for the projections 260. For example, the projections 260 may be pyramidal, conical, frusto-conical, rectangular, square, cylindrical, or portions thereof, or any of various other shapes.
As shown in
In a specific implementation, the projections are machined in a steel bar having a square cross-section profile and a width W (
As shown in
Referring again to
The action of removing the block module from the mold causes the projections 260 to be drawn across the surfaces of the cores, thereby creating roughened surface textures on those surfaces. After a suitable curing period, the block module can be split along lines L1, L2, L3, L4, L5, L6 to separate the block module into individual blocks 202. As can be seen in
Alternatively, the core bars 238, 240, 242 can be used to form roughened surface portions on the uncured block by removing the core bars from the mold such as with conventional core pullers before the uncured block is removed from the mold. It can be appreciated that movement of the core bars relative to the uncured block whether by removing the core bars from the mold or stripping the block from the mold is effective to form roughened surface textures on the surfaces contacting the core bars.
If desired, core bars can be used to form notches or grooves extending horizontally or diagonally across the faces 204, 206 of the block 202. For example, core bars 240 can be positioned horizontally in the mold 200 along lines L1, L2, L3, L4, L5, L6 (
In alternative embodiments, one or more core bars having projections 260 can be used to form notches or grooves in the surface of a block face that is not formed by splitting. For example,
In further embodiments, one or more core bars having projections 260 can be used in combination with a mold in which one or more inner surfaces are formed with block-texturing projections (e.g., projections 106 shown in
In still further embodiments, one or more core bar having projections 260 can be used to form horizontally extending notches or recessed portions in the surface of a block. In one specific implementation, for example, core bars having a configuration similar to core bar 240 (
In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. I therefore claim as my invention all that comes within the scope and spirit of these claims.
The present application claims the benefit of U.S. Provisional Application No. 60/897,027, filed Jan. 22, 2007.
Number | Date | Country | |
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60897027 | Jan 2007 | US |