Note: Descriptions are shown in the official language in which they were submitted.
CA 02669449 2009-06-17
IRREGULAR TESSELLATED BLTII.,DING UNITS
This application is a division of Canadian Patent Application No. 2,519,296,
filed on
March 24, 2004.
Field of the Invention
This disclosure relates to repeating elements forming a surface covering
and/or
structure, and more specifically relates to stones, bricks, pavers and tiles
for forming surface
coverings, walls or other structures.
Background of the Invention
It is well known to cover surfaces, such as walkways, driveways, patios,
floors, work surfaces, walls and other interior or exterior su.rfaces with
stones, bricks, pavers,
tiles and other architectural surface covering units. It is further known to
construct walls and
other structures with stone and bricks. Natural stone surface coverings and
structures are
constructed by cutting and fitting irregularly sized and shaped stones. The
work requires a
skilled stonemason to select, cut and fit the stone. It is labor intensive,
and accordingly
expensive. Custom built natural stone surfaces and structures, however, are
very attractive
and desirable.
Conventional surface coverings and structures are also constructed of
manufactured pavers, bricks, tiles or other units. Manufactured units are
typically provided
in geometric shapes, such as squares, rectangles and hexagons, or combinations
thereof.
Surfaces covered with manufactured units typically are laid in repeating
patterns.
Alteznatively, it is known to lay conventional units in random, non-repeating
patterns.
Random patterns are regarded as esthetically pleasing and are becoming more
popular.
However, random patterns of manufactured units do not have the degree of
natural
irregularity that is desirable in custom stone walkways, driveways, patios,
walls and the like.
Tessellated designs are generally known. For example, M.C. Escher is widely
know to have created tessellated designs comprised of repeating patterns of
recognizable
animals, plants and things, such as geckos, birds, fish and boats. It is an
object of tessellated
design to feature repeating patterns.
Summary of the Invention
According to the present invention there is.provided irregular, tessellated
building units. As used herein, the term "building units" or "units" refers to
a bricks, blocks,
stones, tiles or other two or three dimensional objects that can be used in
the construction of
CA 02669449 2009-06-17
flodrs, walls, retaining walls, columns or other structures, including
interior and exterior
structures, and including load bearing and non-load bearing structures. Each
building unit
has at least one face comprised of one or more primary rotational tessellation
elements.
The primary element has at least two, preferably three vertices. First and
second sides extend in a generally radial direction relative to the first
vertex. The first and
second sides are rotational images of one another. By the term "rotational
image" it is meant
that the sides have substantially the same length and configuration, such that
a first side of
-one unit will mate with a second side of another unit. Third and fourth sides
extend in a
generally radial direction relative to the second vertex. The first and second
sides are
rotationally spaced apart from one another by an angle 0, where 0 is 360
degrees divided by
n, where n is an integer (e.g., 60, 90, 120 or 180 degrees). The third and
fourth sides are
rotationally spaced by an angle rp, where (a is also evenly divided into 360
degrees. The sum
of angles 0 and 9 is preferably 180, 240, 270 or 300 degrees. Preferred
embodiments of the
invention have primary elements with a third vertex, with fifth and sixth
sides extending
ra.dially from the third vertex, rotationally spaced by an angle y. In these
preferred
embodiments, the sum of angles, 6, V and y is 360 degrees. The primary element
may
optionally include a sulistantially straight side.
In accordance with the invention, preferably all the sides of the primary
element are
irregularly shaped. By the terms "irregularly shaped" and "irregular
configuration" it is meant that the
side appears jagged or rough hewn, and is not a straight line or a smooth
curve, such that when multiple
units are assembled to form a surface a regular geometric pattern is not
readily apparent. However, it
should be understood that an irregularly shaped side might comprise a
multiplicity of straight-line
segments, such that the general appearance of the side is irregular.
Optionally, one or more sides could
consist of or include a straight segment or a regular geometric curve.
Each building unit of the invention has at least one face that is comprised of
x
primary elements, where x is an integer equal to or greater than 1, preferably
1 to 6. The
primary element is an irregular rotational tessellation as described above.
Units of different
sizes and shapes can be constructed with different numbers and arrangements of
primary
elements. Because all the units are combinations of primary elements, they
readily mate with
each other. As a result of the irregular side configurations, and different
sizes and shapes of
individual units, one can construct a continuous surface or structure that has
a natural and
non-repeating pattern appearance. As indicated there is a tessellation
pattern, but the pattern
is difficult to visualize. The surface has the appearance of being custom
built.
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One application of the invention is a surface covering. The term "surface
coverings" is used in its broadest meaning, and includes architectural and
product surfaces,
interior and exterior surfaces, and floors, walls and ceilings. The surface
covering comprises
a multiplicity of units assembled to form a continuous surface without overlap
between units
and without substantial gaps between units.
Another application of the invention is constructing walls, columns or other
structures. Each unit has a tessellated front face comprising one or more
primary elements as
described above, sides extending substantially perpendicularly from the front
face, and a rear
face. Preferably, connectors such as lugs or notches are provided to improve
the structural
connection between units. A structure, such as retaining wall, constructed of
such units
having different sizes and shapes will have a natural and custom appearance.
A preferred, optional feature of the invention is a building unit having
spacers
on the sides of the units. The spacers are preferably indented from the
surface, and typically
are not visible in the completed structure. The spacers of each unit define
the primary
element(s) of the unit, and maintain the integrity of the tessellation
pattern. The upper visible
side edges of the unit are varied somewhat relative to mating edges to cause a
variable gap
width between units. Variable gap width further promotes a natural, custom
appearance.
Another optional feature of the invention is providing indicia on or adjacent
one or more sides of each unit to assist in construction of surface coverings
or structures.
Spacers can function as mating indicia. Alternatively, mating indicia can be
separately
provided.
Yet another, optional aspect of the invention is to vary the appearance of
each
unit to further enhance the natural, custom appearance of the surface
covering. Variations
include edge, surface and color variations.
The foregoing and other aspects and features of the invention will become
apparent to those of reasonable sltill in the art from the following detailed
description, as
considered in conjunction with the accompanying drawings.
Brief Description of the Drawings
Figs. 1-10 are illustrations of a first embodiment of irregular, tessellated
building units of the invention.
Fig. 1 is a plan view of a first surface covering of the first embodiment.
Fig. 2 is an enlarged plan view of a primary element for a first building unit
of
the first embodiment.
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Fig. 3 is a plan view of a second surface covering of the first embodiment.
Fig. 4 is an enlarged plan view of a second unit of the first embodiment.
Fig. 5 is a plan view of a third surface covering of the first embodiment.
Fig. 6 is an enlarged plan view of a third unit of the first embodiment.
Fig. 7 is a plan.view of a fourth surface covering of the first embodiment.
Fig. 8 is an enlarged plan view of a fourth unit of the fiirst embodiment.
Fig. 9 is an enlarged plan view of a fifth unit of the first embodiment.
Fig. 10 is an enlarged plan view of a sixth unit of the first embodiment.
Figs. 11-16 are illustrations of a second embodiment of irregular, tessellated
building units othe invention.
Fig. 11 is an enlarged plan view of a primary element for a first building
unit
of the second embodiment. - -
Fig. 12 is a plan view of a second unit of the second embodiment.
Fig. 13 is a plan view of a third unit of the second embodiment.
Fig. 14 is a plan view of a fourth unit of the second embodiment.
Fig. 15 is a plan view of a fifth unit of the second embodiment.
Fig. 16 is a plan view of an exemplary surface covering of the second
embodiment.
Figs. 17 - 22 are illustrations of a third einbodiment of irregular,
rotational
tessellation faces for building units of the invention.
Fig. 17 is an enlarged plan view of a primary element of a first building unit
of
the third embodiment.
Fig. 18 is a plan view of a second unit of the third embodiment.
Fig. 19 is a plan view of a third unit of the third embodiment.
Fig. 20 is a plan view of a fourth unit of the third embodiment.
Fig. 21 is a plan view of a fifth unit of the third embodiment.
Fig. 22 is a plan view of an exemplary surface covering of the third
embodiment.
Figs. 23 -27 are illustrations of a fourth embodiment of irregular,
tessellated
building units of the invention.
Fig. 23 is an enlarged plan view of a primary element for a first building
unit
of the fourth embodiment.
Fig. 24 is a plan view of a second unit of the fburth embodiment.
Fig. 25 is a plan view of a third unit of the fourth embodiment.
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Fig. 26 is a plan view of a fourth unit of the fourth embodiment.
Fig. 27 is a plan view of an exemplary surface covering of the fourth
embodiment.
Fig. 28 is an enlarged plan view of a portion of an example surface covering
of
the invention.
Fig. 29 is an enlarged plan view of a portion of Fig. 28.
Fig: 30 is an enlarged plan view of a second portion of Fig. 28.
Fig. 31 is a cross-section taken along line 31-31 of Fig: 29.
Fig. 32 is a cross-section taken along line 32-32 of Fig. 30.
Fig. 33 is an enlarged plan view of a portion of another example surface
covering of the invention.
Fig. 34 is a cross-section taken along line 34-34 of Fig. 33.
Fig. 35 is a cross-section taken along line 35-35 of Fig. 33.
Fig. 36 is an enlarged plan view of a portion of a further example surface
covering of the invention.
Fig. 37 is an edge detail of a building unit of the invention.
Fig. 38 is an elevational view of a fifth, wall embodiment of the invention.
Fig. 39 is cross-section along line 39-39 of Fig. 1.
Fig. 40 is a perspective view of a two building units of the fifth embodiment.
Fig. 41 is a perspective view of a unit of the fifth embodiment.
Fig. 42 is a perspective view of another unit of the fifth embodiment.
Fig. 43 is an enlarged cross-section of an optional spacer between two units
of
the fifth embodiment.
Fig. 44 is an enlarged cross-section of an optional alternative connector of
the
fi$h embodiment.
Detailed Description of the Preferred Embodiments
Preferred embodiments of the present invention are described below by way of
example only, with reference to the accompany drawings.
Fig. 1 shows a surface covering 10 constructed in accordance with a first
embodiment of the present invention. Surface covering 10 comprises an
arrangement of
building units without substantial gaps or overlapping. The term "substantial
gaps" means
comparatively large gaps, holes or spaces that would detract from the
appearance of the
covered surface. The term, "without substantial gaps" means no gaps and/or
comparatively
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small gaps that may be filled with sand or mortar, which does not adversely
detract from the
appearance of the surface covering or structure. Building units may be molded
or otherwise
made of concrete, stone, ceramics, plastic, natural or synthetic rubber, glass
or other suitable
material, or combinations thereof. In Fig. 1, surface covering 10 is comprised
of three
different sized units 20, 40 and 60. The units have what appear to be
irregular configurations.
Further, the surface covering 10 has the appearance of a natural, custom
surface, i.e., there is
no readily apparent repeating pattern.
An enlarged view of unit 20 is shown in Fig. 2. The unit comprises a single
primary element 20 of a rotational tessellation as will be described in
greater detail below.
Primary element 20 has a fixst side 22 extending between points A and B.
Second side 24
extends between points A and E. A transverse side 26 extends between points B
and E.
Transverse side 26 preferably comprises a series of segments, namely, a third
side 28
extending between points B and C, a fourth side 30 extending between points C
and D, and
an optional fifth side 32 extending between points D and E. First 22 and
second 24 sides are
irregular, rotational images of one another. First and second sides extend in
a generally
radial direction relative to a common first vertex 34, and are rotationally
spaced by an angle
0. Angle 0 is derived from the formula 360 In where the variable n is an
integer, preferably
selected from the group of 2, 3, 4 or 6. Thus, angle 0 is preferably 60, 90,
120 or 180
degrees. Although n is preferably 6 or less, n could be larger than 6 in some
applications. In
the example shown in Fig. 2, the variable n is equal to 6 and 0 is 60 degrees.
The third 28
and fourth 30 sides are rotational images, have a common second vertex 36, and
are
rotationally spaced by an angle rp. Angle (o is derived from the formula 360
/ni where the
variable ni is an integer. Preferably, the sum of angles 0 and V is 180, 240,
270 or 300
degrees. In the example shown in Fig. 2, variable m is 3 and ip is 120 . The
fi$h side 32 is
optional, that is, the third and fourth sides could extend between points B
and E, and thereby
complete the circumference of the unit. The fifth side is a substantially
straight line in this
embodiment. Because the angle 0 is defined as 360 /n, n units may be arranged
in a
rotational tessellation about first vertex 34. Similarly, because the angle lp
is defined as
360 Irn, nt units maybe arranged in a rotational tessellation about second
vertex 36.
Fig. 3 illustrates a surface covering 38 formed of a multiplicity of units 20.
The first sides 22 mate with second sides 24 of adjacent units. In an
analogous fashion, third
sides 28 mate with fourth sides 30 of adjacent units. Fiffth sides mate with
each other. In the
embodiment shown in Fig. 3, six units form a complete rotational tessellation
about first
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vertex points 34. Further, three units form a complete rotational tessellation
about second
vertex points 36.
Fig. 4 illustrates a second, medium size unit 40. Unit 40 comprises two
primary elements 20a and 20b as indicated by broken line 41. Unit 40 has sides
that match
unit 20, namely, a first side 42, second side 44, and transverse side 46
having third sides 48,
fourth sides 50 and fifth sides 52. Unit 40 further includes a first vertex 54
and two second
vertices 56. In unit 40, the angle between first side 42 and second side 44 is
120 .
Fig. 5 illustrates a surface covering 58 comprised entirely of second units
40.
Three units 40 complete a rotational tessellation about vertex 54. Three units
40 also
comprise a complete rotational tessellation about second vertex 56.
Fig. 6 illustrates a third or large unit 60, comprising three primary elements
20c, 20d and 20e as shown by broken lines 61. Unit 60 has sides that match
units 20 and 40,
namely first side 62, second side 64, third sides 68, fourth sides 70, and
fifth sides 72. Unit
60 further includes a first vertex 74 and second vertices 76. In unit 60, the
angle between the
first side 62 and second side 64 is 180 degrees.
Fig. 7 illustrates the surface covering 78 comprised entirely of third units
60.
Two units 60 complete a rotational tessellation about first vertex 74. Three
units 60 complete
a rotational tessellation about second vertices 76.
Figs. 8 - 10 illustrate how building units may be made of different sizes and
shapes by combining primary elements 20. In Fig. 8, unit 80 comprises two
elements 20f and
20g, as reflected by dashed line 81. Unit 80 has two first sides 82, two
second sides 84, a
third side 88, a fourth side 90, and two fifth sides 92. Unit 80 has two first
vertices 94 and a
single second vertex 96.
Fig. 9 illustrates another example unit 100 comprising three primary elements
20h, 20i and 20j, as shown by broken lines 101, that are rotationally
tessellated about second
vertex 104. Unit 100 has three first vertices 102.
Fig. 10 illustrates yet another example unit 110 comprising three primary
elements 20k, 201 and 20m as shown by broken lines 111. Unit 110 has two first
vertices 112
and two second vertices 114. As will be appreciated by persons skilled in the
art, additional
units may be formed in other combinations of primary elements 20. The examples
shown in
Figs 8-10 are not ideal for construction of concrete pavers due to sharp edges
or narrow
mid-sections, but could be feasible if built from other materials. The
examples are presented
to illustrate the concept of forming units having different sizes and/or
shapes by combining
primary elements in different ways.
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Returning to Fig. 1, one can visualize a plurality of units rotationally
tessellated about each first vertex 14 and each second vertex 16. Each
rotational tessellation
may contain one or more small 20, medium 40 or large 60 units, or a
combination thereof.
Because of the irregularly shaped sides of each unit and the size variations
among the units,
the surface appears to be natural and custom fitted, that is, a regular
geometric pattern is not
readily apparent. Although the embodiment of Fig. 1 has three different size
units, namely,
single, double and triple element units, it is contemplated that numerous
variations are
possible, including, for example, a combination of only units 20 and 40, or a
combination of
only units 40 and 60. Further, it is contemplated that a surface covering
could include units
80, 100 or 110, or any other units comprised of a combination of primary
elements.
Figs. 11 - 16 illustrate building units and an exemplary surface covering of a
second embodiment of a rotational tessellation element of the invention. Fig.
11 shows a
primary element 120 comprised of six sides, namely, first side 122 extending
between points
A and B, second side 124 extending between points A and F, third side 128
extending
between points B and C, fourth side 130 extending between points C and D,
fifth side 131
extending between sides D and E and sixth side 133 extending between points E
and F.
Together, sides 3 to 6 form transverse side 126. Element 120 has three
vertices, namely, first
vertex 134, second vertex 136, and third vertex 137. First 122 and second 124
sides are
irregular, rotational images of one another, radiate from first vertex 134,
and are rotationally
spaced by an angle 0 of 60 degrees. The third 128 and fourth 130 sides are
rotational images
of one another, radiate from second vertex 136 and are rotationally spaced by
an angle op of
180 degrees. Fifth 131 and sixth 133 sides are irregular, rotational images of
one another,
radiate from third vertex 137 and are rotationally spaced by an angle y of 120
degrees. All
six sides are preferably irregular in shape.
Fig. 12 illustrates a unit 140 comprised of two basic elements 120a and 120b
as indicated by broken lines 141. Elements 120a and 120b are adjacent elements
in a rotation
about first vertex 134. The basic elements are joined at an interface 141 of
first and second
sides.
Fig. 13 illustrates a unit 160 comprised of two basic elements 120c and 120d
as indicated by broken line 161. The basic elements are joined at an interface
of sides three
and four. Elements 120c and 120d share a second vertex 136.
Fig. 14 illustrates a unit 180 comprised of three basic elements 120e, 120f
and
120g as indicated by broken lines 181. Eleinents 120f and 120g are joined
along first-second
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side interfaces and share a common first vertex 134. Elements 120e and 120f
are joined at
third-fourth side interfaces and share a common second vertex 136.
Fig. 15 illustrates a unit 200 comprised of six basic elements 120h-m as
indicated by broken lines 201. First 134, second 136 and third vertices 137
are identified in
Fig. 15. As one may observe, unit 200 comprises a pair of primary elements
from three
different rotations about first vertices 134.
Figs. 12 - 15 thus illustrate four ways that basic elements may be combined to
form different size and shape units. Additional units may be formed by other
combinations
of primary element 120.
Fig. 16 illustrates an exemplary surface covering formed of the units
illustrated in Figs. 11 - 15. A great variety of surface coverings may be
formed utilizing
combinations of units 120, 140, 160, 180 and 200, as well as other units
formed from
different combinations of primary elements of the second embodiment.
Figures 17 - 22 illustrate building units and an exemplary surface covering of
a third embodiment of the rotational tessellation element of the invention.
Fig. 17 illustrates a primary element 220 of the third embodiment. Primary
element 220 has a first side 222 extending between points A and B, a second
side 224
extending between points A and F. The second side 224 is a rotated image of
first side 222
about first vertex 234. The angle 0 of rotation is 90 degrees in the third
embodiment. Basic
element 220 further includes third side 228 extending between points B and C
and fourth side
230 extending between points C and D. Fourth side 230 is a rotated image of
third side 228
about second vertex 236. The angle of rotation between sides three and four is
angle V which
in case of the third embodiment is 90 . Basic element 220 further comprises a
fifth side 231
extending between points D and E, and a sixth side 233 extending between
points E and F.
Sixth side 233 is a rotated image of fifth side 231 about third vertex 237.
The angle of
rotation y there between is 180 degrees.
Figure 18 illustrates a unit 240 comprised of two primary elements 220a and
220b as indicated by broken lines 241. Primary elements 220a and 220b are
joined at the
interface between sides one and two of the respective units, and share a
common first vertex
234.
Fig. 19 is a third unit 260 comprised of three primary elements 220c, 220d and
220e as indicated by broken lines 261, 263, 265. Elements 220c and 220d are
joined at the
interface 261 of sides one and two of adjacent elements, and have a common
first vertex 234.
Element 220e is joined to element 220d at the interface 263 between sides five
and six,
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respectively, and share common third vertex 237. Element 220e is joined to
element 220c at
the interface 265 between sides three and four, respectively and share common
second vertex
236.
Fig. 20 illustrates a unit 280 comprised of four primary elements from the
third embodiment, namely elements 220f, 220g, 220h and 220i as indicated by
broken lines
281. All four elements revolve around first vertex 234.
Fig. 21 illustrates a fifth unit 300 comprised of four primary elements 220j-
m,
as indicated by broken lines 301. In unit 300 two elements 220j and 220k are
taken from a
rotation about first vertex 234a. Elements 2201 and 220m comprise adjacent
elements about
first vertex 234b.
Figs. 18 - 21 thus illustrate four ways that basic elements may be combined to
form different size and shape units. Additional units may be formed by other
combinations
of primary element 220.
Fig. 22 illustrates a surface covering formed from a mixture of units 220,
240,
260, 280, 300. As with the other embodiments, the surface covering appears to
be an
irregular custom made surface, with no apparent repeating pattern.
Figs. 23 - 27 illustrate building units and a surface covering of a fourth
embodiment of the rotational tessellation element of the invention.
Fig. 23 illustrates a primary element 320 of the fourth embodiment. Primary
element 320 has a first side 322 extending between points A and B, a second
side 324
extending between points A and F. The second side 324 is a rotated image of
first side 322
about first vertex 334. The angle 0 of rotation is 120 degrees in the fourth
embodiment.
Basic element 320 farther includes a third side 328 extending between points B
and C and a
fourth side 330 extending between points C and D. Fourth side 330 is a rotated
image of
third side 328 about second vertex 336. The angle of rotation between sides 3
and 4 is an
angle rp, which in the case of the fourth embodiment is 120 degrees. Basic
element 320
further comprises a fifth side 331 extending between points D and E, and a
sixth side 333
extending between points E and F. Sixth side 333 is a rotated image of fifth
side 331, about
third vertex 337. The angle of rotation y there between is 120 degrees.
Fig. 24 illustrates a unit 340 comprised of two primary elements 320a and
320b as indicated by broken line 341. Basic elements 320a and 320b are joined
at the
interface between sides one and two of adjacent elements, and share a common
first vertex
334.
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Fig. 25 is a third unit 360 comprised of two primary elements 320c and 320d,
as indicated by broken line 361. Elements 320c and 320d are joined at the
interface of sides
three and four of respective elements, and have a common second vertex 336.
Fig. 26 illustrates a unit 380 comprised of three primary elements from the
fourth embodiment, namely, elements 320e, 320f and 320g, as indicated by
broken line 381.
All three elements revolve around first vertex 334.
Fig. 27 illustrate"-surL~me--covering 4QO-forme.d of amixture_of units320,
340, 360 and 380. As with the other embodiments the surface covering appears
to be a
natural, irregular and custom made surface, with a non-ropeating pattedn.
In each of embodiments 1-4 the length of the sides in each pair of sides
radiating from
each respective vertex is substantially the same, e.g., in the first
embodiment, side 22 is the same length
as side 24 and side 28 is the same length as side 30. This facilitates mating
units as discussed above.
However, it is desirable that the lengths of at least one pair of sides in a
unit is different from the other
pairs. Thus, in the case of the first embodiment, sides 22 and 24 are
substantially longer than sides 28
and 30. See Fig. 2. Similarly, in the second embodiment, it can be seen that
sides 122-124 are
substantially longer than both sides 131-133 and sides 126-128. See Fig. 11.
Likewise, each pair of
sides in the third and fourth embodiments have different lengths than the
other pairs. Preferably the
length of each pair of sides is different from the others. Because at least
one pair of sides has a different
length from the others, in combination with the irregular configuration of the
sides, the assembled surface
covering has a natural, random appearance as contrasted with conventional
surfaces that have a
geometric pattern. See, Figs. 1, 16, 22, 27, for example.
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The sum of the vertex angles in embodiments 2- 4 are a11360 degrees.
EMBODIlVIENT ANGLE ANGLE A-NGLE TOTAL
e
2 60 180 120 360
3 90 90 180 360
4 120 120 120 360
Other three vertex tessellations may be provided where each angle 0, p and y
is evenly divisible into 360 degrees and the sum of the angles is 360 degrees.
In
embodiments one, two and three, the angles at the respective vertices are not
the same. In
contrast, the angles are all the same, namely 120 degrees, in embodiment four.
Embodiments
one, two and three, with different vertex angles, produce a more irregular and
hence more
natural looking unit, as compared to embodiment four which appears somewhat
hexagonal.
Accordingly, it is preferred that at least one of the vertex angles is
different than one of the
other vertex angles.
In accordance with the present invention, a wide variety of primary elements
can be designed by those skilled in art. The present invention, defined in the
appended
claims, is not limited to the particular embodiments disclosed. These
embodiments are
illustrative, not limiting. Further it should be understood that the irregular
lines that radiate
from each vertex that are shown in the drawings are merely illustrative of the
concept. The
actual contour of each generally radially extending line is a matter of design
choice and all
configurations are within the scope of the appended claims. Provided, however,
that sides 1-
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2, 3-4 and 5-6, respectively, are substantially rotational images of one
another, as described
above.
To further enhance the natural appearance of the surface covering it is
desirable that the mating edges of adjacent units match less than perfectly,
i.e., that the line or
gap between units vary in thickness. This is preferably accomplished by
introducing minor
variations in the sides of the units so that the first and second sides are
not identical.
Likewise, there may be minor variations between the respective shapes of the
third and fourth
sides, and so on. Variations, however, cannot be so great as to cause problems
in mating
adjacent units. Fig. 28 illustrates minor variations in the thickness of the
gaps 411 and 413
between adjacent units.
A further aspect of the invention is the provision of indicia on the sides or
bottom surfaces of units to assist in the construction of surface coverings.
Figs. 28-- 32
illustrate one example of such indicia. Fig. 28 shows units 410, 412 and 414,
with gaps 411
and 413 therebetween. Fig. 29 shows an enlarged view of area 416. Fig. 30
shows an
enlarged view of area 418. Figs. 28, 29 and 31 show a V-shaped projection 420
from a lower
portion of the second side of unit 410 and a corresponding V-shaped recess 422
in the first
side of unit 412. Similarly, Figs. 28, 30 and 32 show a semi-circular
projection 424 from a
lower portion of the third side of unit 414 and a corresponding semi-circular
shaped recess
426 in unit 410. The size and location of each mating projection-recess are
uniformly located
a consistent radial distance from the applicable vertex. The projections and
recesses are
preferably indented from the surface so that they will not be visible in the
completed surface
covering. Construction is facilitated by easily matching V-shaped projections
and recesses,
and semi-circular projections and recesses, respectively. It should be
understood that the
particular shape of the projections and recesses depicted in the drawings are
merely
illustrative and not limiting. The projections also function to maintain
uniform spacing
between adjacent units even when the thickness of the gaps 411, 413 vary.
Proper spacing
assists in maintaining the integrity of the surface over large areas.
Figs. 33 - 35 illustrate another indicia example to facilitate construction
of,
surface coverings. Fig. 33 is a plan view of two adjacent units 450 and 452
with gap 451
therebetween. Each unit includes a spacer 454 and 456, respectively. Mating
sides of
respective units can be provided with spacers of the same size and location.
Different mating
sides are provided with spacers of a different width "W" or shape. Thereby,
mating sides can
be easily matched. As with the indicia example of Figs. 28 - 32, the spacers
function to
maintain uniform spacing between units despite variations in the width of the
gap 451.
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Optionally, the spacers may be provided with other indicia such as, letters,
numbers or
symbols to facilitate matching as shown for example at reference numeral 456
in Fig. 35.
Figs. 36 and 37 show another example spacer. Fig. 36 shows three units 460,
462, 464, with gaps 461, 463 there between. All of the units have at least
one, preferably a
plurality of spacers on each side. Fig. 36 shows unit 460 having a spacer 466,
unit 462
having spacer 468, 470,. and unit 464 having spacer 472. The spacers in this
example are
adjacent each other to assist in connecting units. The spacers are preferably
located on an
inner portion of the unit and typicaliy are not visible in the completed
surface. See, Fig. 37.
The spacers of each unit define the primary element of the unit, i.e., the
angles angle 8, 9 and
y discussed above are measured in reference to the spacers. To maintain
dimensional
integrity of the surface covering, it is preferable to have at least two
spacers on each side, and
to locate the spacers close to the vertices. Although the spacers could be
located at the
vertices, i.e., corners 482 of the units, it is preferred to locate the
spacers a short distance
from the corner to reduce the potential for chipping or damage in shipment.
Because the
spacers define the primary element, the visible side edges, shown generally at
473, are
independent of the primary element. 'Thus, the configuration of the visible
edge of each side
can be varied with respect to the visible edge of mating sides, which will
result in variable
gap width between units. Variable gap width fizrther promotes a natural,
custom appearance.
Mating of units 460, 462 is facilitated by spacers 466, 468, which help the
installer match mating sides. Similarly spacers 470, 472 facilitate mating of
units 462, 464.
In addition, the spacers interlock and improve the structural integrity of the
surface covering
or structure.
As can be seen in Fig. 36, the irregular sides of units comprise a series of
straight line segments 474, 475, 476, 477, 478, 479. Straight line segments
are preferred for
mold makang. However, the general appearance of the side remains irregular.
An optional beve1480 is provided on edge 473.
Figs. 38-42 show a fifth embodiment of the invention, namely a wall structure.
Wal1510 comprises a plurality of single primary element building units 512,
and a plurality
of two element building units 514. Each unit of the fifth embodiment has a
tessellated front
face in a substantially vertical orientation, whereby assembly of multiple
units forms the wall.
The sides of each unit extend substantially perpendicularly from the front
face, and function
as the top, bottom, right and left sides of each unit. It should be
understood, however, that
although the sides are referred to as top, bottom, right and left for the
purposes of function,
the sides are actually irregalarly shaped and do not lie in horizontal or
vertical planes.
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Further it will be understood that the building units are rotational
tessellations such that what
might be the top of the unit in one instance could be the bottom in another
depending on its
orientation.
The ;6fth embodiment is formed from a multiplicity of building units
assembled to form a continuous structure without substantial gaps between
units. Each unit
is comprised of x primary elements, as discussed above. Unit 512 is comprised
of a single
primary element. Unit 514 comprise two primary elements. The primary element
is an
irregular rotational tessellation as described above. A wide variety of units
may be
constructed having different numbers and arrangements of primary elements.
Because all the
units are combinations of primary elements, they readily mate with each other.
As a result of
the irregular side configurations, and different sizes and shapes of
individual units, one can
construct a wall or other structure that has a natural, random and apparent
custom appearance.
The wall further comprises a base or starter course of units 516 and 518, side
edge units 520, 522 and 524 and top units 526 and 528. Each of these units
comprises a
portion of primary element with a cut, straight side to facilitate
construction. Alternatively,
units may be cut as may be desired on site.
For structural applications of the invention, it is desirable to provide
connectors between units to improve structural integrity. The term
"connectors" means a
feature that aligns adjacent units and assists in maintaining structural
integrity, but does not
require that adjacent units are hooked or coupled together. Fig. 39 shows "S"
shaped
connectors 530 at two locations. An alternative connector is shown in Fig. 41,
comprising
projection-recess type connectors. Connector 532 is a recess, and connector
534 is a
projecting lug having a configuration to mate with a recess 532 of another
unit. Fig. 42
shows yet another connector having on one side, both a lug 536 and a recess
538 to mate with
corresponding recess and lug of another unit. Alternatively the spacers shown
in Figs. 28-37
can be used a spacers and/or connectors in structural applications.
Fig. 43 is an enlarged cross-section between two building units showing an
example spacer 540. As part of the connectors, or as separate features, each
building unit is
optionally provided with spacers. The spacers function to create a
predetermined gap
between units. The gap can provide drainage between units in some
applications, e.g.,
retaining walls, and can be esthetically desirable. Further, the spacers
assist in properly
spacing units, which is important to maintaining integrity of the "pattern"
over large areas.
Without spacers small pebbles or debris can be trapped between units, throwing
off the
"pattern." A further function of the spacers is to improve the structural
integrity of the wall.
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Because the spacers have a relatively small surface area as compared to the
side walls, a
higher surface pressure (or stress) is applied between the spacer and the
adjacent brick,
causing the spacer to "dig into" the adjacent unit. The gaps between units
formed by the
spacers can remain open if desired. Alternatively the gaps may be filled in
whole or in part
with grout, mortar, sand or other fillers. Grout or mortar further simulates
hand laid stone,
and adds to the stability of the structure.
Fig. 44 shows flattened saw-tooth connectors 544 between two building units
546 and 548. The upper unit 546 is recess rearwardly from the lower unit 548.
This feature
is desirable for retaining walls. Another prefeared feature is chamfered or
beveled edges 542
between the front and side faces of each unit. Chamfered edges are both
functional and add
to the appearance of the units.
To further improve the natural appearance of surface coverings it is desirable
to provide variations in individual units. Dyes and colorants may be added to
the units, and
the color and quantity of dye may be regalated to produce color variations
from unit to unit.
Surface variations from unit to unit are also desirable. One method of
introducing surface
variation is to tumble the units after curing. Tumbled units and methods for
tumbling are
well known in the art. An alternative method is to hammer the surface of the
unit to create
small nicks or marks. Surface variations also may be made in the molds. For
example, in a
six form assembly, each mold can include a different surface irregularity or
variation.
Thereby, only every sixth unit would be the same.
The building units of the invention may be made in any conventional manner,
for example by molding. - Two preferred molding methods are dry cast and wet
cast. Dry cast
material can be used to mass manufacture low cost units. Wet cast is more
expensive, but
produces very high quality units. A preferred dry cast method is slip-form
molding from dry
mix concrete to form units suited for use in walkways, driveways and patios.
In the wet cast process, a form is constructed with side walls conforming to
the planar configuration of the unit (as discussed above) with a bottom of the
form designed
to mold what will be the outer or top surface of the unit. The unit is molded
upside down by
pouring a concrete mixture into the form and allowing it to cure. An advantage
of the wet
process is that natural stone materials and other desirable additives may be
introduced that are
not compatible with mass production by the dry cast process.
Another form of building units of the invention comprises molding stamps,
each stamp being comprised of one or more primary elements. Molding stamps are
known to
persons skilled in the art. Generally, a surface is formed by pouring,
spreading and leveling
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concrete. While the surface is wet (uncured) molding stamps are pressed into
the surface, the
surface being molded to conform to the stamp. In forming a stamp molded
surface at least
one stamp is required, but preferably several stamps are used, including
stamps of different
sizes and/or shapes resulting from different combinations of primary elements.
The stamp
molds are aligned and mated one to another in the same manner as described
above in
reference to pavers. The finished surface has a natural stone appearance,
without an apparent
repeating pattern, but is actually a concrete slab.
While preferred embodiments of the invention have been herein illustrated and
described, it is to be appreciated that certain changes, rearrangements and
modifications may
be made therein without departing from the scope of the invention as defined
by the
appended claims.
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