U.S. patent application number 11/342753 was filed with the patent office on 2007-08-23 for dry-cast concrete block.
Invention is credited to Charles N. Klettenberg, Robert R. Sycks.
Application Number | 20070193181 11/342753 |
Document ID | / |
Family ID | 38426726 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070193181 |
Kind Code |
A1 |
Klettenberg; Charles N. ; et
al. |
August 23, 2007 |
Dry-cast concrete block
Abstract
A concrete wall block manufactured using the dry cast process
includes a top surface and a bottom surface. Opposing front and
rear surfaces extend between the top surface and the bottom
surface. Opposing first and second sidewall surfaces extend between
the top surface and the bottom surface, and between the front and
rear surfaces. The front surface and the first sidewall surface
have a three dimensional texture imprinted thereon. The rear
surface and the second sidewall surface may be smooth. The
texturing on the front and first sidewall surfaces may generally
resemble natural stone.
Inventors: |
Klettenberg; Charles N.;
(Maple Grove, MN) ; Sycks; Robert R.; (Elk River,
MN) |
Correspondence
Address: |
PATTERSON, THUENTE, SKAAR & CHRISTENSEN, P.A.
4800 IDS CENTER
80 SOUTH 8TH STREET
MINNEAPOLIS
MN
55402-2100
US
|
Family ID: |
38426726 |
Appl. No.: |
11/342753 |
Filed: |
January 30, 2006 |
Current U.S.
Class: |
52/596 |
Current CPC
Class: |
B28B 15/005 20130101;
B28B 3/021 20130101; B28B 3/022 20130101; B28B 7/0041 20130101;
E04C 1/395 20130101 |
Class at
Publication: |
052/596 |
International
Class: |
E04C 2/04 20060101
E04C002/04 |
Claims
1. A dry-cast concrete wall block comprising: a top surface; a
bottom surface opposing front and rear surfaces extending between
the top surface and the bottom surface; and opposing first and
second sidewall surfaces extending between the top surface and the
bottom surface, and extending between the front and rear surfaces
wherein the front surface and the first sidewall surface have a
three dimensional texture imprinted thereon.
2. The concrete wall block of claim 1, wherein the rear surface and
the second sidewall surface are smooth.
3. The concrete wall block of claim 1, wherein the texturing on the
front and first sidewall surfaces generally resembles natural
stone.
4. The concrete wall block of claim 1, wherein the texturing of the
front and first sidewall surfaces covers their entire extent.
5. The concrete wall block of claim 1, further comprising an
interlocking protrusion extending below the bottom surface of the
block.
6. A dry-cast concrete wall block comprising: a top surface; a
bottom surface spaced apart from the top surface and defining a
thickness of the block; a first side surface extending between the
top surface and the bottom surface, the first side surface having a
three dimensional texture imprinted thereon; a second side surface
extending between the top surface and the bottom surface, the
second side surface having a three dimensional texture imprinted
thereon; a third side surface extending between the top surface and
the bottom surface, the third side surface opposing the second side
surface; a fourth side surface extending between the top surface
and the bottom surface, the fourth side surface opposing the first
side surface.
7. The concrete wall block of claim 6, wherein the third side
surface is tapered.
8. The concrete wall block of claim 6, further comprising an
interlocking extension extending below the bottom surface.
9. A dry-cast concrete wall block comprising: a top surface; a
bottom surface spaced apart from the top surface and defining a
thickness of the block; a front surface extending between the top
surface and the bottom surface; a rear surface opposite the front
surface and extending between the top surface and the bottom
surface; and opposing side surfaces spanning between the front and
back surfaces, wherein the front surface and one of the opposing
side surfaces are configured to simulate natural stone.
10. A method of manufacturing an uncured concrete block made using
the dry-cast manufacturing process, the method comprising the steps
of: providing a mold, the mold comprising a pair of side walls, a
pair of end walls, an open top side and an open bottom side
defining a mold cavity; providing a pallet; providing an end liner
within the mold cavity; positioning the pallet with respect to the
mold to temporarily close the open bottom side of the mold during a
portion of the manufacturing process; moving each a first end liner
from a strip position to a fill position; introducing a dry casting
concrete mixture to the mold through the open top side; vibrating
the concrete mixture within the mold; compacting the concrete
mixture within the mold by pressing on the concrete mixture with at
least one shoe attached to a compression head to impart a
decorative face on the concrete mixture; moving each the first end
liner from the fill position to the strip position; and releasing
the concrete mixture from the mold by moving the pallet relative to
the mold.
11. The method of claim 10, further comprising the step of forming
a decorative pattern on a side face of the uncured concrete block
with the first end liner.
12. The method of claim 10, further comprising the step of forming
a tapered side face on the uncured concrete block with the first
end liner.
13. The method of claim 10, further comprising the step of
providing a second end liner to each mold cavity disposed opposite
the first end liner.
14. The method of claim 10, further comprising the step of heating
the first end liner.
15. The method of claim 10, further comprising the step of
providing a division plate within the mold to define multiple mold
cavities.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to the manufacture
of concrete wall blocks. More specifically, the present invention
relates to the manufacture of concrete wall blocks using the
dry-cast method wherein the blocks have two or more adjacent
decorative faces.
BACKGROUND OF THE INVENTION
[0002] Concrete blocks are used to form free standing and retaining
walls. In such applications, the visible face or faces of the
blocks are often provided with a textured or decorative appearance.
Concrete blocks for forming walls are used in a variety of
applications from small gardening applications to large-scale
construction projects. Blocks are stacked in horizontal rows called
courses. Multiple successive courses may be used to create a
vertically rising wall of a desired height.
[0003] The concrete blocks used in constructing such walls are
often manufactured using the dry cast process, which uses dry-cast
block machinery to form blocks at a relatively high rate of speed.
In a typical dry-cast block machine, material is fed into an open
top mold from the top side. The conventional mold consists of
stationary sides, to define the sidewalls of the block, and an open
bottom. A removable pallet is used to temporarily close the open
bottom of the mold and serve as a base during the block forming
operation.
[0004] During manufacture, the material introduced through the open
top collects on top of the pallet and is bounded by the end and
side panels. A compression head is then pressed downwards under
high pressure onto the material through the open top of the mold to
compact the material therein. The head forces material into the
mold so as to conform to the shape of the mold. The mold may also
be vibrated during compaction to promote uniform compaction. The
head may also be provided with one or more shoes that have relief
defined therein in order to impart detail into the material that is
contacted by the head's movement.
[0005] After compaction and vibration, the bottom pallet drops
down, the head follows the pallet and the newly made product
downward while the sides of the mold remain in position, and when
the product clears the bottom of the mold, the pallet moves away
from the mold and another pallet moves in place to make the next
product. The head returns to its original position and the feed
drawer brings more material into the mold to make the next product.
The molding machinery is able to cycle several times per
minute.
[0006] U.S. Pat. No. 5,827,015 teaches the use of conventional dry
cast molding methods to form a twinned concrete slug in the molding
machinery. The slug is then split into two blocks after being
cured. It should be appreciated that the top surface of the
finished wall block made according to the conventional dry cast
manufacturing method is formed by the surface of the steel pallet.
The bottom of the block is accordingly formed by the stripper
shoe.
[0007] The need to eject the formed blocks through the bottom of
the mold used in dry cast manufacture places limitations on the
ability to create a decorative front face on the block because of
the sidewalls of the mold shear across the side surfaces of the
block when stripped from the mold. Therefore, efforts have been
made to provide for a decorative front face on concrete wall
blocks.
[0008] One common current method of producing a wall block with a
decorative front surface is to split a cured block (or a twinned
slug) so that the front surface of the block has a fractured
concrete surface that looks somewhat like split rock. This is done
by forming a slug in a mold and providing one or more grooves in
the slug to function as one or more splitting planes. The slug is
then split apart to form two or more blocks. The appearance of the
face of such block is exhibited by U.S. Pat. No. D380,560. This
gives the front face of structures built with these blocks some
visual depth that makes the structure look more natural. The number
of facets and their arrangement can be varied to provide for
different looks such as shown in U.S. Pat. No. D429,006.
[0009] More recent patents, such as U.S. Pat. No. 6,321,740,
disclose modification of the splitter blade used in splitting the
cured block to provide edges that appear more weathered. Splitting,
however, adds additional production costs by requiring an
additional step to the manufacturing process and results in waste
material. Furthermore, split-faced concrete blocks do not
sufficiently resemble natural stone to satisfy some consumer
needs.
[0010] Another method to make blocks that have decorative front
surfaces are described in U.S. Pat. Nos. 5,078,940; 5,217,630; and
6,224,815. These patents describe a method and an apparatus for
manufacturing a concrete block having an irregular surface. The
irregular surface can be made to look similar to split stone. This
method includes pouring uncured block material into a mold cavity
and causing a portion of the material to be retained in place
relative to the cavity walls when the block is removed from the
cavity. The result is a somewhat split appearance for the surface,
without having to perform the splitting operation. However, the
block produced from this method still does not satisfactorily
resemble natural stone.
[0011] Other methods employed to provide for improved decorative
appearance include spraying the front face of an uncured block to
wash away some cement to leave exposed aggregate. Another method
consists of "weathering" a cured block by tumbling it in a tumbler
with tumbler chips that knock off random pieces of the block, which
rounds the ends and creates a look closer to the appearance of
weathered stone. These methods, however, are labor intensive and
can damage the blocks, resulting in a higher overall cost of
production.
[0012] Commonly owned, copending application Pub. No. US
2004/0218985, which is hereby incorporated by reference in its
entirety, discloses an alternative method of providing a decorative
simulated natural stone face to the front surface of a block while
using the dry cast manufacturing method. The molding apparatus is
configured such that the front surface of the block faces up in the
mold and can therefore be provided with a pre-defined decorative
face because the shoe stamps or contacts it directly. This process,
however, limits the ability to provide for sidewalls that deviate
from conformance to the smooth vertical sidewalls of the mold box
because the downward movement of the block through the mold
prevents a mold with stationary angled sidewalls or relief from
being used.
[0013] U.S. Patent Pub. Nos. 2003/0126821 and 2003/0182011 disclose
a block machine that stamps a face on the front surface of a block
while also providing a tapered sidewall to the block by use of
pivoting sidewalls. However, this system does not teach the ability
to impart a complex decorative face on the side surfaces of the
blocks. In addition, the mold must be taken apart to a degree that
makes it difficult to perform maintenance or repairs of the biasing
mechanisms. This difficulty can cause undesirable delays in
production. Accordingly, there remains a need to provide an
improved machine and method of making dry-cast concrete blocks that
is maintenance friendly and can produce blocks having complex
decorative patterns on at least two adjacent faces.
SUMMARY OF THE INVENTION
[0014] The concrete wall block according to certain embodiments of
the present invention provides advantageous adjacent decorative
surfaces and can be manufactured using the dry cast process.
Moreover, the decorative faces do not need to be formed by a
secondary splitting, weatherizing or texturizing process after
curing.
[0015] According to certain embodiments of the present invention, a
concrete wall block manufactured using the dry cast process
includes a top surface and a bottom surface. Opposing front and
rear surfaces extend between the top surface and the bottom
surface. Opposing first and second sidewall surfaces extend between
the top surface and the bottom surface, and between the front and
rear surfaces. The front surface and the first sidewall surface
have a three dimensional texture imprinted thereon. The rear
surface and the second sidewall surface may be smooth. The
texturing on the front and first sidewall surfaces may generally
resemble natural stone.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a top view of a mold apparatus according to an
embodiment of the present invention in a first position.
[0017] FIG. 2 is a top view of a mold apparatus according to an
embodiment of the present invention in a second position.
[0018] FIG. 3 is a top view of a mold apparatus according to an
embodiment of the present invention showing both the first and the
second position.
[0019] FIG. 4 is a side view of a pair of end liners and a
compression head assembly according to an embodiment of the present
invention.
[0020] FIG. 5 is a top view of a pair of end liners and a
compression head assembly according to an embodiment of the present
invention.
[0021] FIG. 6 is a partial perspective view of a mold apparatus
according to an embodiment of the present invention.
[0022] FIG. 7A and FIG. 7B are top views of a floating connection
according to an embodiment of the present invention.
[0023] FIG. 8A is a perspective view and FIG. 8B is a top view of a
concrete block according to an embodiment of the present
invention.
[0024] FIG. 9A is a perspective view and FIG. 9B is a top view of a
concrete block according to an embodiment of the present
invention.
[0025] FIG. 10A is a perspective view and FIG. 10B is a top view of
a concrete block according to an embodiment of the present
invention.
[0026] FIG. 11A is a perspective view and FIG. 11B is a top view of
a concrete block according to an embodiment of the present
invention.
[0027] FIG. 12A is a perspective view and FIG. 12B is a top view of
a concrete block according to an embodiment of the present
invention.
DETAILED DESCRIPTION
[0028] Referring to FIGS. 1-3, there can be seen a dry-cast block
mold 100 according to an embodiment of the present invention. FIG.
I depicts block mold 100 in the "release" or "strip" position. FIG.
2 depicts block mold 100 in the "fill" position. Both the strip
position and the fill position are shown in FIG. 3, with the strip
position shown in dashed lines and the fill position shown with
solid lines.
[0029] Dry-cast block mold 100 is generally comprised of a pair of
side bars 102, 104 and a pair of side plates 106, 108 that define
an open interior region. Division plates 110 span side bars 102,
104, creating multiple mold cavities 112. A front end liner 114 and
a rear end liner 115 are disposed in each mold cavity 112. One of
skill in the art will recognize that the number of divider plates
may be varied to increase or decrease the number of mold cavities,
and accordingly, the respective number of end liners.
[0030] Front end liners 114 are connected and controlled by a front
end liner connector assembly 116. Front end liners 114 are each
connected to a front end liner push member 120. Front end liner
push members 120 are coupled to one another by a front end liner
push bar 122, to which each front end liner push member 120 is
connected with a fastener 124. An actuator attachment member 126
and floating connector 128 are also connected to front end liner
push bar 122. An actuator 144 attached to actuator attachment
member 126 can therefore control all front end liners 114
simultaneously.
[0031] Rear end liners 115 are actuated by a rear end liner
connector assembly 118. Rear end liners 115 are connected to rear
end liner push members 130 which are linked to one another by a
rear end liner push bar 132 to which they are attached with
fasteners 134. Rear connector members 136 are similarly attached to
rear end liner push bar 132 and run along side plates 106, 108
where they connect to a connector bar 140. Also attached to
connector bar are two actuator attachment members 140 with floating
connectors 142 to which actuators 145, 146 can be attached to
control movement of rear end liner connector assembly 118.
Actuators 145, 146 attached to actuator attachment members 140 can
therefore control all rear end liners 115 simultaneously.
[0032] Referring to FIGS. 4 and 6, each front end liner 114 is also
attached to a pair of guide members 121 that are aligned parallel
to end liner push members 120. Similarly, each rear end liner 115
is attached to a pair of guide members 131. Guide members 121, 131
are function to maintain the alignment of end liners 114, 115 and
to resist rotational forces throughout the molding process.
[0033] Mold box 100 will generally rest in the strip position shown
in FIG. 1 when the machine is idle. The machine is moved into the
fill position depicted in FIG. 2 so that it can be filled with
dry-cast concrete mixture. This is done by actuating a front end
liner actuator 144 attached to front end liner connector assembly
116 that pushes front end liners 114 forward towards the middle of
cavities 112. Rear actuators 145, 146 attached to rear end liner
connector assembly 118 also pull rear end liners 115 forward
towards the middle of cavities 112. The mold cavities 112 are then
filled with mold material and the actuators 144, 145, 146 hold the
end liners 114, 115 in place while the mold is filled, vibrated and
compacted. When the mold material is stripped from the mold, front
end liners 114 are pulled back and rear end liners 115 are pushed
back to the strip position by their respective actuators 144, 145,
146.
[0034] Actuators 144, 145, 146 move front end liners 114 and rear
end liners 115 in opposite directions at the same time. Front
actuator 144 and rear actuators 145, 146 are thus operated out of
phase from one another, because while one end liner set is pushed
the other is pulled. Front actuator 144 is preferably a core
puller, such as those sold by Besser Company of Alpena, Michigan.
The normal stroke of such a core puller, which is about 19 inches,
is limited by a mechanical stop 148 which confines the core
puller's stroke to about 2 inches. Rear actuators 145, 146 are
preferably 2" air cylinders attached to the core puller's frame.
One of skill in the art will recognize that numerous other front
and rear actuators may be used, for example, hydraulically actuated
cylinders or other pneumatically actuated cylinders. Gear or
linkage based actuators may also be used without departing from the
scope of the present invention.
[0035] Referring to FIGS. 4 and 5, the outside edges of the head
shoe 154, 156 of the head assembly 150 are given cooperating relief
to the top portion of the faces of each pair of end liners 114,
115. This configuration allows both the head shoe 152 and the end
liners 114, 115 to fully contact the mold material, and thus impart
a higher quality face, when the end liners 114, 115 are in the fill
position and the head shoe 152 is being used to compress the
material. It will be appreciated that the use of both a head shoe
and end liners to provide a face to the block allows a block to be
produced that has a decorative appearance on as many as three
consecutive sides.
[0036] End liners 114, 115 may be used to either impart a
decorative pattern or to provide a taper to the block sides as the
user desires. Although depicted in FIGS. 4 and 5 as having tapered
end liners 115 on one side and faced end liners 114 on the other,
mold box may have identical end liners on both of its ends. In one
preferred configuration, a smooth non-tapered end liner is used on
one side while the opposing end liner includes three dimensional
relief to imprint three dimensional texture in the side face
adjacent to the top face. It should be appreciated that a portion
of the side of the head shoe 152 may need to be provided with
complimentary relief to conform to the relief in end liner 114.
Otherwise, a tight tolerance between the head shoe 152 and end
liner 114 will not be possible and material may undesirably flow
into the gap formed therebetween during the forming process.
[0037] End liners 114, 115 can provide decorative appearances with
greater detail and relief than can be provided using conventional
techniques, such as splitting and tumbling. Such decorative
appearances include broken rock, stacked rocks, natural stone,
brick, striated or roughened texture. Persons of skill in the art
of concrete block manufacturing using the dry-cast process will
recognize that various decorative appearances can be imparted on
the front surfaces of the blocks, and that the present invention is
not limited to a specific decorative facial appearance unless
specifically indicated in a given Claim.
[0038] To prevent concrete material from accumulating on faced end
liners 114 and degrading the quality of the decorative appearance
imparted to the block surface, end liners 114 may be heated. Heat
is provided to end liners 114 by operatively connecting at least
one heat element (not shown) to end liners 114. Suitable heat
elements include resistance elements that may be hard wired, solid
state, or semiconductor circuitry. Head shoe 152 may also provided
with a heat source 158, as is known in the art. The divider plates
and mold cavities may also be heated.
[0039] Each actuator is connected to an end liner connector
assembly by a floating connector 125 depicted in FIGS. 7A and 7B.
Floating connector 125 includes a female portion 128, which is
connected to end liner connector assembly by an attachment member
126, and a male portion 129, which is connected to actuator by an
attachment member 127. To connect, the male connector portion 129
simply slides into the female connector portion 128 downwardly from
the top surface of female portion 129 or upwardly from the bottom
surface of female portion 129. Floating connector 125 allows for up
and down vibration during the molding process, but constrains
movement in the front to back and side to side directions. This
holds the assembly in place to allow end liners to impart relief in
the mold material, but allows sufficient motion to minimize the
likelihood of failure of the connecting members.
[0040] Referring to FIGS. 8A-8B, there can be seen an embodiment of
a concrete block 200 that can be made using the dry cast block mold
100 according to an embodiment of the present invention. Block 200
comprises a front surface 202 and opposing rear surface 204, a top
surface 206 and opposing bottom surface 208, and opposing first 210
and second 212 side surfaces. Front surface 202 has a decorative
appearance imparted by the head shoe because front surface 202
faces up in the mold. Side surface 212 has a decorative design
imparted by either a front or rear end liner having decorative
relief defined therein. End liner 114 of FIG. 4 can be used to make
the decorative side surface 212 shown in FIGS. 8A and 8B. The
opposing end liner is smooth to provide for a smooth side surface
210. Alternatively, as shown in FIGS. 9A and 9B, block 300 may be
provided with decorative faces on front surface 302 and both first
310 and second 312 side surfaces. This is done by providing the
mold with both front and rear end liners having decorative relief.
A further alternative, shown in FIGS. 10A and 10B, is to provide a
block 400 with decorative side surfaces 410 and 412 and a smooth
front surface 402. In such an application, textured front and rear
end liners are used while the head shoe is smooth to create a
smooth front surface. The pattern given to decorative faces can
vary depending on the desired appearance for a particular wall or
wall section, as explained previously. Decorative faces in a
particular block may have the same or different appearance.
[0041] FIGS. 11A-11B depict another embodiment of a concrete block
500 that can be made using the dry cast block mold 100 according to
an embodiment of the present invention. Block 500 comprises a front
surface 502 and opposing rear surface 504, a top surface 506 and
opposing bottom surface 508 and opposing first 510 and second 512
side surfaces. Front surface 502 has a decorative appearance
imparted by the head shoe. Side surfaces 510, 512 are both tapered.
Blocks with one or more tapered side surfaces are particularly
adapted to create serpentine or otherwise curved walls. End liners
similar to the end liner 115 depicted in FIGS. 4 and 5 are used to
make such a block 500.
[0042] FIGS. 12A-12B depict a concrete block 600 that includes a
decorative front surface 602 with an opposing rear surface 604, a
top surface 606 and opposing bottom surface 608, and first 610 and
second 612 opposing side surfaces. This block 600 is formed,
however, using one textured face end liner and one smooth tapered
end liner, such that side surface 612 is tapered and side surface
610 has a decorative appearance.
[0043] Blocks made according to the present invention may also be
provided with an interlocking extension to facilitate stacking of
blocks and create a setback between courses of blocks. A mold for
creating such a block is disclosed in commonly-owned copending
application Pub. No. 2004/0218985, incorporated by reference above.
To modify the mold of the present invention to produce blocks with
protrusions in addition to multiple faces or tapers, a notch in the
shape of the desired protrusion is added to the division plates as
disclosed in the above publication.
[0044] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the Claims.
* * * * *