Patent Grant
8464481
1. Field of the Invention
The present disclosure relates generally to the field of segmental retaining walls and, more specifically, to corner blocks for use in forming a corner of a segmental retaining wall and techniques for manufacturing segmental retaining wall corner blocks.
2. Background Information
Retaining walls are widely used in a variety of landscaping and construction applications. Typically, they are used to maximize or create level areas and also to reduce erosion and slumping. They may also be used in a purely decorative manner. In the past, retaining wall construction was labor intensive and often required the skills of trained tradespeople such as masons and carpenters. More recently, retaining wall construction has become significantly simplified with the introduction of self-aligning, modular, molded blocks of concrete that may be stacked in courses without the use of mortar or extensive training. With these types of retaining wall blocks, it is possible to erect a segmental retaining wall quickly and economically, and the finished product creates the impression and appearance of a conventional block-and-mortar retaining wall.
One feature that allows the foregoing blocks to be so easily and precisely assembled is the interconnection between adjacent courses of blocks. Typically, each retaining wall block has one or more projections and one or more recesses located at oppositely facing surfaces, such as a top surface and a bottom surface, for example. The projections and recesses are complementarily shaped, with the projection protruding beyond the top (or bottom) surface of the block with the recess extending inwardly from the bottom (or top) surface of the block. In use, the projections of a first block are received within the recesses of a second block to interconnect and position the blocks one atop the other in a predetermined relation. When assembling a retaining wall, such interconnections make it possible to lay successive courses of blocks in an accurate and expedient manner. Moreover, such an assembled retaining wall is able to resist lateral forces exerted by the material being retained and reduce bowing. Blocks having these interconnections are usually the same size and may be assembled in a coplanar arrangement in only a simple, running bond pattern. Application Ser. No. 11/900,434, which is incorporated by reference herein in its entirety, discloses retaining wall blocks in which the projections and recesses are arranged so that adjacent courses are set back or offset a predetermined amount. With this type of retaining wall block, each successive course is offset from the preceding course by the same amount (setback) so that the assembled wall is skewed or sloped at a predetermined angle from the vertical.
When installing a segmental retaining wall, it is often necessary to construct a 90-degree corner which requires use of corner blocks. In the case of segmental retaining walls in which each successive course is set back a predetermined setback from the preceding course, each successive corner block must also be set back from the preceding corner block. Moreover, the setback of the stacked corner blocks must be the same as that of the retaining wall and furthermore, the setback must be formed on two sides of the corner to match the setback of the two runs of the retaining wall that extend from the corner.
The segmental retaining wall industry has several methods of providing for an interlocking stacked corner using corner blocks, both with and without external connectors. These include:
(1) A raised front lip which engages the bottom front and side of an upper corner block. This block must be made with an external “core puller” which adds time to the manufacturing cycle and therefore is costly to produce.
(2) A lower rear lip which engages the top rear surface of a lower corner block. This block utilizes one of its “full stretcher” blocks that has been manually hand-split to provide the corner piece. This method therefore is costly to produce.
(3) A lower core that engages the inside front and side wall of a lower corner block inside the block cavity. This block is manufactured as a solid unit and therefore is costly to produce.
(4) Other corner blocks are installed utilizing pins or connectors and therefore are costly to produce.
An object of the present invention is to provide a corner block that may easily be assembled, without the use of mortar, to construct a corner of a segmental retaining wall.
Another object of the present invention is to provide a corner block for a segmental retaining wall or other wall structure that can be easily and rapidly stacked atop another corner block and interlocked therewith without use of external connectors.
A further object of the present invention is to provide a corner block for constructing a corner of a segmental retaining wall or other wall structure, in which one corner block can be stacked atop another corner block with the two exterior sides of the upper corner block set back from the two exterior sides of the lower corner block.
Another object of the present invention is to provide a corner structure formed of stacked corner blocks that are interlocked with one another with each successive corner block having at two exterior sides offset from the two exterior sides of the preceding corner block.
A further object of the present invention is to provide two corner blocks that are the mirror image or opposite hand of each other and that can be alternatingly stacked one atop another to construct a corner of a segmental retaining wall or other wall structure.
A further object of the present invention is to provide a method of manufacturing a plurality of corner blocks in one manufacturing cycle.
The foregoing and other objects of the present invention are achieved by a corner block having spaced-apart front and rear sections interconnected by two laterally spaced-apart side sections that jointly define a through-cavity that extends through the block from a top face thereof to a bottom face. Upper protrusions are provided on the top face of the block, and lower protrusions are provided inside the cavity at the bottom of the block. The upper and lower protrusions are configured and arranged relative to one another so that when two blocks are stacked one atop another with one block rotated 90 degrees relative to the other, the upper protrusions of the lower block interlock with the lower protrusions of the upper block to interlock the two blocks.
The lower protrusions extend lengthwise along opposed walls of the cavity at the bottom of the block, each opposed wall having two protrusions which are spaced apart to form a gap between the two protrusions. The upper protrusions include two protrusions provided on the top face of the rear section of the block, the two protrusions being spaced apart from one another a distance equal to the gap between the lower protrusions so that when an upper block is placed on a lower block, the two upper protrusions on the lower block fit within the gaps formed by the lower protrusions on the upper block so that the upper and lower protrusions engage with one another to interlock the two blocks. At the same time, the opposed walls of the cavity straddle and engage with the two upper protrusions to interlock the two blocks.
The corner blocks are constructed in two variants, a corner block A and a corner block B, which are mirror images or opposite hands of each other. The corner blocks A and B are alternately stacked upon one another to construct a 90-degree corner of a segmental retaining wall or other wall structure. Each corner block has two exposed or exterior sides, and the two exterior sides of each successive corner block are set back or offset from the two exterior sides of the preceding block by a predetermined setback.
A third upper protrusion is provided on the top face of the corner block and extends from one side section lengthwise along the front section. The third protrusion is dimensioned and positioned to engage with an outer surface of an upper block to thereby assist in interlocking the upper and lower blocks.
The corner blocks A and B are manufactured in a four-block unit. The four-block unit consists of two diagonal corner blocks A and two opposing diagonal corner blocks B that are produced in one manufacturing cycle and subsequently split to form four individual corner blocks.
Additional objects, advantages and features of the disclosure will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the disclosure. The objects and advantages of the disclosure may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The figures in the drawings are simplified for illustrative purposes and are not necessarily depicted to scale. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
The appended drawings illustrate exemplary embodiments of the disclosure and, as such, should not be considered as limiting the scope of the disclosure that may admit to other effective embodiments. It is contemplated that features or steps of one embodiment may be beneficially incorporated in other embodiments without further recitation.
The term “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or design described herein as “exemplary” or “alternative” is not necessarily to be construed as preferred or advantageous over other embodiments or designs.
The corner block of the present invention has two variations, which are mirror images or opposite hands of each other. In the following description, these two variations are referred to as corner blocks A and B. The reference numerals used to describe corner block A have the suffix “a”, and the same reference numerals with the suffix “b” are used to describe corner block B. Reference numerals without the suffixes “a” or “b” refer to corresponding elements or parts of both corner blocks A and B.
Referring to the drawings,
The interconnected front, side and rear sections define a center through-cavity (internal cavity) 14a that extends completely through the corner block A from a top face 4a of the block to a bottom face 5a. The cavity 14a has a slight inward taper, generally on the order of 1°-1½°, in the top-bottom direction, as best seen in
As described later, in use the corner blocks A and B are stacked alternately one atop another to form the corner of a retaining wall or other wall structure. When alternately stacked in this manner, each two adjacent corner blocks A and B interlock with one another with the upper block set back or offset a prescribed setback distance relative to the lower block. This set back occurs in two orthogonal directions so that the corner formed by the stacked alternating corner blocks A and B has two sloped sides and can be used to interconnect at 90 degrees two sloped walls formed of segmental wall blocks that are set back from course to course.
The locking system for locking adjacent upper and lower corner blocks A and B comprises locking members in the form of protrusions or protruding portions provided on the corner blocks. Each corner block has upper protrusions on the top face thereof and lower protrusions on the inside of the internal cavity thereof at the base of the block. When a corner block B is properly positioned atop a corner block A, the upper protrusions of the block A engage with the lower protrusions of the block B and with preselected surface portions of the block B to interlock the two stacked blocks. When a corner block A is properly positioned atop a corner block B, the upper protrusions of the block B engage with the lower protrusions of the block A and with preselected surface portions of the block A to interlock the two stacked blocks. A wall corner of desired height is erected by alternately stacking the corner blocks A and B upon one another in interlocking fashion.
As used herein, the term “protrusion”, unless otherwise qualified, is used in its broadest sense to refer to a protruding part, without limitation as to any particular configuration, including a lug, projection, knob, tab and protuberance.
With reference to the corner block A, the locking system comprises two upper protrusions or protruding portions 6a provided on the top face 4a of the rear section 12a rearwardly of the cavity 14a. In this exemplary embodiment, the protrusions 6a are generally rectangular in shape and each have an outer end face 7a that is flush with the outer face of the rear section 12a, an inner end face 8a that is flush with the inner face of the rear section 12a, and two opposed side faces or edges 9a that extend between the end faces 7a,8a. Another upper protrusion or protruding portion 15a is provided on the top face 4a in the region where the right side section 13a joins the front section 10a. In this exemplary embodiment, the protrusion 15a is generally rectangular in shape and extends lengthwise along the top face 4a of the front section 10a from the right side section 13a to a preselected point beyond the corner of the internal cavity 14a. As shown in
The locking system further includes lower protrusions or protruding portions 20a,21a at the base or bottom part of the corner block A. As illustrated in
In corner block A, the front section 10a and the left side section 11a have textured outer or front surfaces and in corner block B, the front section 10b and the right side section 11b have textured outer or front surfaces. The textured surfaces terminate at the top and at opposite sides in curved edges, and the bottoms of the textured surfaces are flat and coplanar with the bottom face of the blocks. All of the curved edges are rounded and have the same size, shape and curvature that create an aesthetically pleasing appearance.
The corner blocks A and B can be used in conjunction with any compatible segmental wall block, such as the segmental retaining wall blocks disclosed, for example, in application Ser. No. 11/900,434 which is incorporated by reference herein in its entirety, which are designed to minimize the likelihood of vertically aligned joints in adjacent courses of blocks and which have successive courses of blocks set back or offset from one another. Similarly, by alternating between corner block A and corner block B in successive courses, there would be no vertically aligned joints at the corner of the wall, and successive corner blocks would be offset from one another in the same manner and to the same degree as the successive courses of blocks in the remainder of the wall.
By way of example, and to facilitate understanding of the disclosure, the following exemplary dimensions are given for the corner blocks A and B. The invention is not, of course, limited or restricted to these dimensions, which are provided solely for illustrative purposes. To manufacture corner blocks of different sizes, these dimensions may be scaled up or down, or other dimensions could be used, as would be well understood by persons ordinarily skilled in the art. In the case of the exemplary embodiment illustrated in
The method of stacking alternating corner blocks A and B to construct a 90-degree corner will next be described with reference to
This locking system is obtained by setting the dimension a between the outside edges 9a of the two protrusions 6a equal to the width dimension d of the cavity opening 14b″ at the bottom of block B, setting the length dimension c of the protrusion 6a of block A equal to the gap dimension d between the opposed end faces 22b,23b of the protrusions 20b,21b of block B and setting the length dimension e of the protrusion 15a of block A equal to the length dimension f minus the width dimension g of block B minus the setback S2 of block B relative to block A.
Provision of the protrusion 15a stabilizes the locking together of the corner blocks A and B and prevents shifting of the blocks in case there is slight play between one or both of the protrusions 6a and the protrusions 20b,21b or between the outside edges of the protrusions 6a and the bottom wall portion of the internal cavity 14b. Thus the protrusion 15a could be omitted though its inclusion is preferable. As another alternative, instead of the two protrusions 6a,6a, a single protrusion that extends the length of dimension a could be used. The single protrusion would function like the two protrusions 6a,6a and has two opposite outside edges that engage with the opposed end faces 22b,23b of the protrusions 20b,21b. The height of the protrusions 20b,21b is not critical though it is preferable that the protrusions have a height greater than that of the protrusions 6a.
As illustrated in
Though the locking system has been described with respect to stacking a corner block B on a corner block A, the same locking system applies when stacking a corner block A on a corner block B. This is illustrated in
The method of manufacturing the corner blocks A and B will next be described with reference to
Once the concrete is mixed, it is transported to a hopper, which holds the concrete near a mold (not shown). In this exemplary embodiment, the mold is constructed to permit the formation of a block unit 30, as shown in
When forming the block unit 30, a flat production pallet (not shown) made of steel, plastic, or wood, for example, is positioned beneath the mold. After positioning the pallet beneath the mold, an appropriate amount of concrete mixture from the hopper is loaded, via one or more feed drawers, into the mold assembly (e.g., via the mold cavities). The process and equipment for transporting the concrete mixture and loading it into the mold are well known in the art.
The concrete mixture in the mold must next be compacted or consolidated to densify it. This is accomplished primarily through vibration of the concrete mixture, in combination with the application of pressure exerted on the concrete mixture from above. The vibration can be exerted by vibration of the pallet underlying the mold (table vibration), or by vibration of the mold (mold vibration), or by a combination of both actions. As is well known in the art, the pressure is exerted by a compression head that carries one or more stripper shoes that contact the concrete mixture from above. The timing and sequencing of the vibration and compression is variable, and depends upon the characteristics of the concrete mixture and the desired results. The selection and application of the appropriate sequencing, timing, and types of vibrational forces, are within the ordinary skill in the art. Generally, these forces contribute to fully filling the mold (e.g., the forming cavities), so that there are not undesired voids in the finished block, and to densifying the concrete mixture so that the resulting finished corner blocks A, B will have the desired weight, density, and performance characteristics.
After densification, the pre-cured block unit 30 is discharged from the mold. Preferably, discharge occurs by lowering the pallet relative to the mold, while further lowering the stripper shoe through the mold cavity to assist in stripping the pre-cured block unit 30 from the mold. The stripper shoe is then raised upwardly out of the mold and the mold is ready to repeat this production cycle.
After curing, the cured, molded block unit 30 consists of four corner block structures that are joined together at common interfaces along split lines 31 and 32, with each of the corner block structures having the protrusions 6,15 protruding outwardly from the top face thereof and the protrusions 20,21 protruding inwardly from the wall of the cavity 14. The cured, molded block unit 30 is then removed from the pallet and transported to a splitting station where it is split along the split lines 31,32 to separate the block unit 30 into two corner blocks A and two corner blocks B. The split lines 31,32 are formed during molding of the block unit 30 and correspond to the perimeter of the opposed textured front surfaces of the confronting blocks. The splitting process can be performed manually using a chisel and hammer or can be performed using machines known to those skilled in the art for such purposes. After the splitting process, each of the corner blocks A, B is provided with a textured front surface and a textured side surface both of which are exposed and visible when the corner blocks are assembled to form a corner as shown in
Once split, the corner blocks A, B can be packaged for storage and subsequent shipment to a jobsite, and can then be used in forming a corner structure for a retaining wall or other wall structure.
From the foregoing description, it can be seen that the present invention comprises improved corner blocks, methods of manufacturing the corner blocks, and corner structures formed of the corner blocks. It will be appreciated by those skilled in the art that obvious changes can be made to the embodiments described in the foregoing description without departing from the broad inventive concept thereof. It is understood, therefore, that this disclosure is not limited to the particular embodiments disclosed, but is intended to cover all obvious modifications thereof which are within the scope and the spirit of the disclosure as defined by the appended claims.
This application claims the benefit of U.S. Provisional Application No. 61/214,252 filed Apr. 21, 2009.
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|---|---|---|---|
| 1534353 | Besser | Apr 1925 | A |
| 4107894 | Mullins | Aug 1978 | A |
| 4186540 | Mullins | Feb 1980 | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20100263310 A1 | Oct 2010 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61214252 | Apr 2009 | US |
