Note: Descriptions are shown in the official language in which they were submitted.
1~76864
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MORTARLESS CONCRETE BLOCK SYSTEM
HAVING REINFORCING BOND BEAM COURSES
B~ckground of the Invention
1. Field of the Invention: The present inven-
tion relates to molded concrete blocks fox masonry con-
struction, and specifically to mortarless interlockingblocks for such use.
2. Prior Art: In the prior art, concrete
blocks have been molded with tongue and groove inter-
locking provisions in their top and bottom surfaces and
end surfaces for mortared block systems, as shown in
U.S. Patent No. 3,256,657 to Phipps, U.S. Patent No.
811,534 to Akers, et al, U.S. Patent No. 2,482,719 to
Rigaumont, and U.S. Patent No. 2,~52,463 to Herbert, as
well as for mortarless block systems, as shown in U.S.
Patent No. 3,962,842 to Wilhelm, and British Patent No.
166,623 to Christmas.
Each of the above-named patents discloses
s~ecial corner blocks for its specific interlocking
s~stem; Wefit German Patent No. 2,200,015 to Bender dis-
closes special'corne'r blocks;'but is without inter-
locking features on the upper and lower block surfaces
and does not provide for reinforcing rods.
6~64
--2--
No known prior mortarless block construction
system provides secure T-intersections and crossing-wall
intersections.
Bond beam courses are made up of channel-like
blocks which receive steel reinforcing rods and grouting
to form a horizontal beam to strengthen the structure,
as in French Patent No. 2,346,514 to Bastianelli. French
Patent No. 546,143 to Vaux discloses an interlocking
concrete block having end webs which may be broken away
to receive horizontal reinforcing rods. Similarily US
Patent No. 989,677 to Wiederholdt shows break-away end
webs in a building tile to be secured to adjacent tiles
by interior grouting only. No prior block construction
provides for reinforcing the corners of bond beam courses
except by extensive on-site modification.
Summary of the Invention
An object of the present invention is to
provide a mortarless system of interlocking molded
concrete blocks in which only a minimum number of blocks
need be manufactured, and more specifically, to provide
such a system having a general purpose corner or intersection
block which may be utilized for both right and left corners,
partition walls, pilasters and crossing-walls. A second
object is to provide such a mortarless interlocking block
system without blocks having projections extending outward
from the block side faces, whereby to permit efficient
use of standard molding apparatus. Another object is
to provide a similar bond beam intersection block which
may be utilized for both right and left corners and for
partition walls, to receive horizontal reinforcement
which extends through the corner.
1176~364
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For constructing r~ght and left corners, and
T-shaped and crossing-wall intersections, the system has
general purpose intersection blocks, each comprised of
two portions. Its inner end portion is somewhat conven-
tional, with a pair of parallel mating grooves formed inits inner end face and a pair of parallel mating ridges
formed on its upper surface, as well as a pair of para-
llel mating grooves formed into its lower sur~ace. How-
ever, its corner end portion, outer end face and two oppo-
site side faces each have a pair of parallel verticalmatina grooves, which will receive the parallel vertical
tongues of stretcher blocks, while its corner end portion
top surface is without ridges, thereby accommodating the
bottom surface of a corner end portion of a similar int-
ersection block of the next upper course positioned there-
on at right angles thereto or in ~ar alignment therewith.
For bond bea~ oourses, which are horizontally rodded
and grouted by utilizing channel-shaped bond beam blocks,
the system has a corresponding bond beam intersection
block whose i~ner end portion has a channel hollow ex-
tending from its inner end face, which is vertically
grooved, into its corner end portion, which has a hollow
vertical core continuing from the inner end channel hol-
low. The interior of the corner end portion is vertic-
ally grooved similar to the general purpose intersectionblock. The vertical core has a plurality of breakout pro-
visions for opening its side and end faces. The contin-
uous horizontal roddins and grouting so affor~ed through
bond beam courses and vertical grouting through said ver-
tical cores provide a strong interlocking grid. Rein-
forcing rods having right angle bends with the corner end
portion of the corner block and extending horizontally
into both adjacent blocks may be used to tie the two walls,
preventing cracking. Likewise, right-angle reinforcing
rods may be installed in a vertical plane extending from
a bond beam course upward or downward throuoh a grouted vertical
core adjaoent to a window or door, or at a wall intersection.
1176864
Brief Description of the Drawings
Figure 1 is an isometric view of a general
purpose intersection block embodying the present in-
vention, shown from above and from its outer or corner
end;
Figure 2 is an isometric view of the general
purpose intersection block of Figure 1 shown inverted
and from its inner end;
. Figure 3 is an isometric view of a stretcher
block, for use with the general purpose intersection
block of Figure 1, shown from above;
Figure 4 is a bottom isometric view of the
stretcher block of Figure 3;
Figure 5 is a top isometric view of a chan-
nel bond beam block having saddle-like webs to support
a reinforcing rod;
~ igure 6 is a sectional view taken along
line 6-6 of Figure 5;
Figure 7 is an isometric view of a bond beam
intersection block embodying the present invention,
taken from above and from its outer or corner end;
Figure 8 is a longitudinal sectional view
ta~en along line 8-8 of Figure 7;
Figure 9 is an isometric view of a plurality
of courses of blocks embodying the present invention,
showing the intersection of a forward wall with a left
wall and a partition wall. A half-length block is
shown to the right of the partition wall in the course
there uppermost;
Figure 10 is a sectional view taken along
line 10-10 of Figure 9, from above the second course,
showing the intersection of the forward wall with the
partition wall;
Figure 11 is an isometric view of a wall
_ . _ .. .. ..
system embodying the present invention, a bond beam
course with reinforcing rods in pl~ce, prior to grouting;
Figure 12 is an isometric view of an alterna-
~1768G4
tive bond beam intersection block, shown receivingright angle reinforcing rods and vertical rodding in
its corner end; a side face of the block inner end
is partially broken away to show the bottom knocked
out to receive a second vertical rod in the cores ad-
jacent to the corner core;
Figure 13 is a plan view of a reinforced
bond beam course utilizing the intersection block and
right angle reinforcing rods of Figure 12.
Description of the Preferred Embodiment
-
The present invention comprises a mortarless
system of interlocking molded concrete rectangular
blocks of an established depth, including numerous
blocks of varying shapes and lengths, each for differ-
ent purposes. Typically, the blocks are 8 inches high(20.32 cm~, 16 inches long (40.64 cm) and nominally 8
inches wide (20.32 cm) lactually slightly less]. Such
block is referred to, both in the trade and in this
specification, as an 8 inch (20.32 cm) block and is the
type shown in the drawings. Bloc~s of similar heighth
and length, but of 12 inch width (30.48 cm), are refer-
red to as 12 inch (30.48 cm) blocks. The present system
is described herein with reference to 8 inch (20.32 cm)
blocks, but those of other widths may be used, with
2~ slight modi~ications which will be apparent.
The most extraordinary results af the present
invention follow from the features of construction of
the blocks used at intersections, at corners and at
lntermediate partition walls, of both the unreinforced
courses and the reinforced courses kno~n as bond beam
courses. ~he intersecti~n blocks so used will be des-
cribed after describing the other blocks used in such
courses.
Full-length Stretcher Blocks
_ . _ . . .
The most often used blocks in the system are
full-length stretcher blocks, shown in Figures 3 and
4 and generally designated 10, which are positioned
,: .
1~76864
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atop and overlapping one another to form the wall be-
tween corners. They have a generally flat upper sur-
face 11 on which are formed a pair of parallel hori-
zontal ridges 12, one near each edge of the block's
long sides. In the embodiment shown, the ridge is
three-fourths inch ~1.905 cm) in width and three-
eighths inch (.95 cm) in heighth, and is spaced three-
eighths inch (.95 cm) from the block edge. The ridges
12 are shown ending spaced from the block end face,
but it may be preferable in many circumstances to pro-
vide them extending to the end face, especially where
a good vapor barrier is required. The full-length
stretcher block 10 has a lower surface 13 in which are
formed a pair of parallel horizontal grooves 14 at
the same spacing as for the upper surface horizontal
ridges 12, hereinafter referred to as the ridge spacing,
and matable therewith when one block 10 is positioned
atop a second block 10 with their side faces 15, which
are flat, in alignment.
The stretcher blocks 10 have a first end 16
on which are formed a pair of parallel vertical tongues
17, here shown at approximately the same spacing as the
upper surface ridges 12, but hereinafter referred to as
the tongue spacing. The opposite or second end 18 of
the stretcher block 10 has a pair of parallel vertical
grooves 19 at the above-described ton~ue spacing, thus
being matable with the first end vertical tongues 17.
Each stretcher block 10 has a pair of four-sided verti-
cal cores or hollows 20 extending between its upper sur-
face 11 and lower surface 13, one located at each endof the block 10,
Reversal Stretcher Blocks
For masons to reverse the full-length stretcher
blocks 10 so that their first tongued ends 16 are orien-
ted in the opposite direction tnan other blocks in thesame course, the system is provided with reversal stret-
cher blocks, not shown, which are similar to the full-
1~76864
length stretcher blocks 10. The reversal stretcherblocks differ only in that their second ends have,
instead of grooves, a second pair of parallel vertical
tongues identical to the tongues on their first ends.
Shortened Stretcher BlocXs
The mortarless block system also has blocks
shorter than the full-length stretcher blocks, in the
embodiment shown, being a half-length block or half-
block 30, shown in Figure 9 in the forward wall third
course at the right side of the partition wall. The
configuration of the ends and the upper and lower sur-
faces of the half block 30 are identical to the full-
length stretcher blocks 10. For block systems of other
widths, such'as 12 inches (30.48 cm), the length of the
sh~rtened stretcher blocks would be substantially equal
to the difference between the length and width of the
stretcher blocks 10.
General-Pur se 'Intersec'tion' Blocks
po
In the mortarless block system, the stretcher
blocks 10 are not adapted to fit atop one another at
right angles as in forming corners or at intersections
~ith partition walls. To serve these functions, the
present system provides general purpose intersection
blocks, generally designated 40 and shown in Figures 1
Pnd 2, of substantially the same exterior dimensions as
the full-length stretcher blocks 10. These intersection
blocks have corner end portions so different from their
inner portions as to require separate description.
The general purpose intersection blocks 40
each have an inner end portion, generally designated 41;
this portion has an inner end face 42 with a pair of
parallel vertical grooves 43 at the tongue spacing,
li~e the second end 18 of the full-length stretcher
blocks 10. The inner end portion upper surface 44'has
3~ a leng~hwise pair of'parallel horizontal ridges'45
~hile the lower surface 46 has a pair of parallel hori-
zontal grooves 47, both pairs being at the rîdge spacing
1~76864
as in the full-length stretcher blocks 10. The inner
end portion 41 has a four-sided hollow vertical core
48 which extends from its upper surface 44 to its lower
surface 46 in substantially similar position to the
stretcher block vertical core 19.
The corner end portion 51 of each intersec-
tion block 40 has an outer end face 52 with a pair of'
parallel vertical grooves 53 formed at the tongue spac-
ing. ~t further has a first side face 54 with a pair
of vertical parallel grooves 55 at the tongue spacing
and a second opposite side face 56 having an identical
pair of vertical parallel grooves 57 at the tongue spa-
. cing. Its upper surface 58 continues linearly from theinner end portion upper surface 43, but is without
ridges. Its lower surface 59 similarly continues from
the inner end portion lower surface 45; and the grooves
47 of the inner end portion 41 continue therealong to
the outer end face 52. The corner end portion 51 has
a similar vertical core or hollow 61 extending from the
upper surface 58 to the lower surface 59.
; Bond Beam Channel Blocks
Intermediate of horizontal courses comprised
of stretcher blocks ~0 and general purpose intersection
blocks 40, and at the top of walls, the system utilizes
~;25 bond beam courses, which are concrete blocks adapted to
~contain hori~ontal reinforcing rods b surrounded by
:' grout, placed in position after the blocks-have been
laid.
To comprise the major portion of the bond beam
courses~ between corners and other wall intersections,
;the system has bond beam channel blocks, generally desig-
nated 70 and shown in Figu~es 5 and 6, which are substan-
tially equal ln length to the full-length stretcher
blocks 10, and are generally channel-like in structure.
The channel blocks 7'0' each have a pair of vertical - .
sides or side walls 71 whi~h extend upward from a U-
shaped solid channel bottom 73 forming, with the side
1~76864
walls 71, a channel. The first end 74 of each channel
block 70 has a pair of parallel vertical tongues 75 at
the tongue spacing, identical to the full-length stret-
cher block first end 16. The opposite or second end
76 has a pair of parallel vertical grooves 77 at the
same tongue spacing. The channel block upper surface
78 has a pair of parallel horizontal ridges at the ridge
spacing, as in the full-length stretcher block upper
surface 11; one ridge will be at the top of each side
wall 71. The channel block lower surface 50 has a pair
of parallel horizontal grooves 81 at the ridge spacing;
identical to the full-length stretcher block lower sur-
face 13.
At the first end 74, the second end 76, and
spaced halfway therebetween, the channel block 70 has
V-shaped saddle-'like webs 82 projecting upward from the
channel bottom 73 and extending between the side walls
71. These serve both to reinforce the channels and to
sup~ort horizontal reinforcing rods b above the channel
bottom 73 and below the upper surface of the block 70,
as shown in Figure 6. Alternately, as in Figure 13j the
saddle-like webs 82 may be U-shaped, the saddles having
a somewhat flat bottom, for use with the alternative
bond beam in~ersection block of Figure 12, described
below.
Bond Bea~ Inter's'e'cti'on Blocks
To connect corners and partition walls in bond
bea~ courses utilizing the bond bea~ channel blocks 70,
the system has bond beam intersection blocks, generally
designated 90, which are of the same established depth
as the full-length stretcher blocks 10. The bond beam
intersection blocks 90, like the general purpose inter-
section blocks 40, are best described as being made up
of t~70 portions, an inner end portion and a corner end
~ortion, as sho~-m in~Figures 7 and 8.
The inner end portion, generally designated
91, has vertical side walls 92 ending outwardly in an
inner end face 93 which has formed therein a pair of
i~76864
--10--
parallel vertical grooves 94, spaced at the tongue
spacing. The side walls 92 extend from an uppex sur-
face 95, which has formed thereon a pair of parallel
horizontal ridges at the ridge spacing, to a lower
surface 97 having formed the ein a pair of parallel
vertical grooves 98 at the same ridge spacing. Uni-
queIy, the inner end portion 91 has a horizontal chan-
nel hollow 99 extending inward through the inner end
face 93 and ending downwardly in a solid channel bottom
100. Both its inner end face 93 and at its opposite
end, (which corresponds to an intermediate web and
leads to the corner end portion described below) the
inner end portion 91 has V-shaped saddle-like webs 101
similar to the channel block saddle-like webs 82, ex-
tending between the side walls 92 and projecting above
the channel bottom lO0, the saddle being of such depth
as to support rodding above the level of the channel
bottom 100 and below the upper surface of the inner
end portion 91, as shown in Figures 8 and ll.
The corner end portion, generally designated
110, has an outer end face 111 with a pair of parallel
vertical grooves 112 formed therein at the tongue spac-
ing, a first opposite side face 113 with a pair of
parallel vertical grooves 114 formed therein at the
tongue spacing, and a second opposite side face 115,
again with parallel vertical grooves 116 at the tongue
spacing.
;~ The corner end upper surface 117 continues
linearly from the inner end portion upper surface 95,
but unlike the inner end portion, is without ridges.
The corner end portion lower surface 118 similarly con-
tinues from the inner end portion lower surface 97,
whose parallel horizontal grooves 98 continue through
this portion. Extending between the upper and lower
surfaces 117, 118 is a four-sided vertical core or hol-
low 120 to which the horizontal channel hol~ow 99 in
the inne~ end portion 91 extends. The vertical core
1~76864
120 has pairs of parallel vertical breakout score lines
121 extending toward the first opposite side face 113,
second opposite side face 115 and the outer end face
111 downward from the corner end portion upper surface
117 ending upward of the corner end portion lower sur-
face 118, as shown in Figure 8.
An alternative bond beam intersection block,
generally designated 130, is.shown in Figures 12 and
13. It is similar to the above-described bond beam
intersection block of Figures 7 and 8, and its features
are similarly designated, except that the inner end face
93 and the intermediate web instead have U-shaped sad-
dles 131 which have a somewhat flat bottom 132. Figure
12 shows the block 130 accommodating reinforcing rods
133 each having an intermediate right angle bend and
two rectilinear elongated portions extending therefrom.
One such reinforcing rod 133 is shown in a horizontal
plane for.connecting two bond beam channel blocks in the
same course at the adjacent ends of two perpendicular
walls; another is shown in a vertical plane for connec-
ting a bond beam channel course to the aligned grouted
cores of general purpose intersection blocks 40 at wall
intersections, or to stretcher blocks 10 adjacent to
windows and doors.
2~ Manufacture of the Present Invention
-
Each of the above-described blocks, being sub-
stantially 8 inches in width (20.32 cm), may be manu-
factured in modified standard molds which accommodate
three such 8 inch (20.32 cm) blocks side by side. O.her
standard molding equipment is utilized, typically having
movablé pallets on which blocks are formed by hydraulic
manipulation of mold parts.
Cons.ructing Walls with the Present Invention
Construction of running-wall portions utili-
zing the stretcher blocks of the present invention is
substantially similar to the construction of other mor-
tarless block walls. The primary differences lie in in-
1~76864
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tersections, as at corners, partition walls and crossing-
walls, as well as at the bond beam courses. In forming
each intersection at which a forward wall meets another
wall at right angles, as shown in Figure 9, in courses
made up by stretcher blocks, a general purpose inter-
section block 40, as shown in Figure 1, is utilized.
Sin oe the corner end upper surfaces 58 of the
general purpose intersection blocks 40 are flat and un-
ridged, onto each will fit the lower surface 59 of a
similar intersection block of the next upper course fit-
ted thereon at right angles. Adjacent ~o the inner end
portion 41 of each is a stretcher block 10, whose ton-
gues 17 engage the inner end grooves 43. On the other
side of the corner, another stretcher block 10 has its
vertical tongues 17 engaged in the grooves of one of the
side faces 54, 56 of the intersection block 40. The
grooves of the other side face and outer end face are
seen on the outer wall surface and may be considered to
be of decorative value; however, their presence permits
blocks of identical conformation to be used at both
right and left corners, and linearly at intermediate
portions where partition walls intersect, as hereafter
described. From the corner, the wall continues in both
- directions with additional full-length stretcher blocks
lO.
Persons skilled in the art will realize that
~efore another corner is reached, it will be necessary
to utilize a double-tongued or reversal stretcher block
as described above so that the general purpose inter-
section block 40 utilized at the next corner may receive
vertical tongues. The corner is further strengthened
by vertical reinforcing rods a in the intersection block
corner end portion vertical core 61, along with grout
poured therein as the wall is being built.
_ . . .
An example of construction of a partition wall
:hich interlocks with a forward wall is shown in Figure
9. At the partition in~ard of the right side of the
1176864
,
!
--13--
drawing, the lower two courses each utilize generalpurpose intersection blocks 40. Viewing the course
shown in Figure 10, their second side face vertical
grooves 57 are mated to vertical parallel tongues 17
of partition wall stretcher blocks. These general pur-
pose intersection blocks 40 are mounted in linear a-
lignment with the stretcher blocks of the forward wall;
hence, the tongues 17 of adjacent stretcher blocks are
inserted matingly in the corner block outer end face
grooves 53 at all such courses. In the course below
that shown in Figure 10, the corresponding general pur-
pose intersection block 40 is reversed left to right,
but its corner end portion 51 is directly beneath that
of the overlaying couxse. Hence, the tongues 17 of the
partition wall stretcher block at the lower of these
courses will mate with the corner block opposite side
face grooves.
For the third, or uppermost course of the
partition, as shown in Figure 9, a general purpose in-
tersection block 40 extends forward from the partitionwall, at a right angle to the forward wall blocks, to
have its corner end portion 51 lie vertically above
~ the corner end portion 51 of the second course inter-
; section block 40. Its inner end portion 41 forms part
of the partition wall, overlapping the full-length
stretcher block 10 in its second course. The deficiency
of wall length, caused by using only the width of this
intersection block at the third course, is compensated
for by inserting a half-block 30, whose vertical tongues
engage the second side face vertical grooves 57. The
full-length stretcher blocks 10 and a reversal stretcher
block, as described, lead to the next corner. In this
example, other courses above these three described al-
ternately have these configurations of blocks.
Si~ilarly, should it be desired to have a
wa l cxoss anG,her, the general purpose intersection
blocks 40 may be used to provide, at such crossing inter-
sections, both the interlocked connections, as at the
il76864
-14-
upper part of Figure 9, and the non-interlocked inter-
sections shown in Figure 10. This is made possible
because these intersection blocks have vertical grooves
on each of the three surfaces of their corner ends.
In construction of bond beams, bond beam in-
tersection blocks 90 as shown in Figures 7 and 8, or
the alternative bond beam intersection block 130 as
shown in Figure 12, are utilized at corner, partition
wall and crossing-wall intersections, with bond beam
channel blocks 70 forming the bond beam courses there-
between. At a corner of the uppermost course shown in
Figure 11, a bond beam intersection block 90 is posi-
tioned linearly continuing from one bond beam channel
block 70 and at right ang}es to another, with its cor-
ner end portion 110 atop the general purpose intersectionblock corner end portion 51 of the course below. By
breaking out the bond beam intersection block 90 between
its breakout score lines 121 which extend toward its
first side face 113, preferably down to the level at
which the saddle 82 will support a reinforcing rod,
horizontal reinforcing rods b may be laid to extend
through the channel blocks on each side of the corner
end to the vertical core 120 at the corner. Vertical
reinforcing rods a and grout through the hollow verti-
cal core 120 are there connected to the horizontal rodsb.and grout, to form an interlocking grid.
At intersections with partition walls, to tie
the horizontal rods- b and grout from a running forward
wall into the partition wall, a bond beam intçrsection
block is utilized, as shown near the right side of the
upper course in ~igure 11. The bond beam intersection
block corner end portion 110 receives in the grooves
116 of its second side face 115 the end tongues 75 of
a bond beam channel block 70. By breaking away the
3S corner end portion 110 between that portion of the sid~ .
face 115 between its score lines 121 and also breakihg
away the score lines 121 in its outer end face 111 ad-
il~76864
jacent the linearly abutting channel block 70, hori-
æontal reinforcing rods b there intersecting can be
tied together and the grout can flow together, forming
a strong link between the bond beams. Unbroken pairs
of breakout score lines 121 become filled with grout
and the block is then of unimpaired strength. Verti-
cal reinforcing rods a and grout in the corner end
portions of both the bond beam intersection block 90
and general purpose intersection blocks 40 complete the
integral reinforced concrete grid. Should there be a
crossing-wall intersection, all three score~ faces of
the corner end portion llO of the bond beam intersection
block 90 will be broken away so that there may be a
four-way reinforced intersection.
The alternative bond beam intersection block
130 is used in a similar manner for corners and par-
tition walls, as shown in Figure 13. Its U-shape sad-
dles and broken out portions may accommodate multiple
side-by-side reinforcing rods~ including the horizontal
right angle rod 133 whose intermediate right angle bend
is received and accommodated within the cored corner
end 110 of the corner block 130; one of its elongated
; rectilinear end portions extends through the broken-
away portion between the score lines 121 of the side
face 115 to the adjacent ~ond beam channel block of the
perpendicular wall. The other elongated end extends
through its inner end 91 to an adjacent linearly con-
tinuing bond beam channel block 70. Conventional
straight reinforcing rods b overlap the right angle rod
133; if desired they may be tied together by conventional
means, though it is through to be unnecessary.
`~ As further shown in Figure 12, the right angle
rod 133 may be installed in a vertical plane, with one
of its rectili1~ear end portions extending horizontally
in the bond beam course and its opposite end portion ex
tending vertically, upward or downward, either through
the corner ends of the general purpose intersection
11~76864
-16-
blocks 40 at a wall intersection or through the cores
of stretcher blocks adjacent to windows and doors.
In either case, the reinforcement provides added
strength where most needed, to prevent the cracking
which is likely to occur with conventional construction.
If even greater strength is required where
intersection blocks are utilized, the vertical cores
adjacent to the intersection may be rodded and grouted,
such as suggested in Figure 12. The solid bottom of
the inner end of the bond beam intersection block may
be knocked out and a vertical reinforcin~ rod and grout
installed. The bond beam intersection block may be
provided with score lines or a thinned area in the
inner end bottom to facilitate knocking out such a
portion.
Universal Intersection Blocks
As an alternative'embodiment of the present
invention, the mortarless concrete block system may
utilize universal intersection blocks at corners, par-
tition walls, crossing-walls, or pilasters of both
bond beam courses and the non-reinforced courses be-
tween them, in substitution for the general purpose
blocks 40 and bond beam intersection blocks 90.
Such universal intersection block, not shown
in the drawings, has a corner end portion identical
with that of the bond beam intersection block 90. ~ow-
ever, its intermediate web has score lines, extending
from the corner core, similar to the score lines in
the other sides of the core. Its inner end portion
is also like that of a bond beam intersection block 90,
characterized by ease of fabrication, advantageous
thermal insulating properties, desirable surface fin'
ishes and similar considerations.
The educational value to children of building
.. . _.. . . . ..
with toy blocks has long been recognized. The confor-
mations of the present general purpose 'intersection
blocks, together with stretcher blocks, reversal blocks
1~76864
-17-
and half blocks, make their combination a system well
suited for toy use when made of molded plastic. The
corner end portions of the intersection blocks may be
adapted to receive corner posts of such cross-section
as to press-fit within their vertical cores, so as to
secure the intersection blocks, stacked alternately
at right angles, by their corner end portions. These
and other modifications will, from the above disclosure,
be apparent to persons skilled in the art.
. - .
