Reinforcement support spacer

A reinforcement support spacer for spacedly positioning one or more concrete reinforcement members from a surface on which concrete is poured. The spacer comprises a support which has at least one recess therein for receiving a reinforcement member. Barbs or tines formed integrally with the support project into the recesses. The barbs or tines on each recess are oriented so as to permit a reinforcement member to be forced past the barbs or tines into the recess but substantially to prevent a reinforcement member from being forced past the barbs or tines out of the recess once a reinforcement member has been inserted into the recess. The support spacers of the present invention permit reinforcement members to be preassembled in spaced relationship to each other and installed as an assembly. The preassembled reinforcement assembly can be lifted onto the surface on which concrete is to be poured, saving on-site labor costs involved in assembling at the point of use.

BACKGROUND OF THE INVENTION 
The present invention relates to concrete reinforcements, and in 
particular, to a device for supporting and spacing such reinforcements and 
a reinforcement assembly using the device. Typically, concrete is 
reinforced by mats or layers of reinforcing bar and/or welded wire fabric. 
Each reinforcement layer or mat is suspended within the concrete 
structure. During pouring of the concrete, especially during pouring of 
horizontal slabs, it is necessary to suspend the reinforcing steel above 
the surface on which the concrete is poured. Often, a second layer or mat 
of reinforcement steel is spaced above the first reinforcement steel layer 
or mat in the concrete structure. Therefore, a supporting and spacing 
device is necessary to hold the reinforcement steel mats in their 
designated positions while the concrete is poured. The supporting and 
spacing device remains in the hardened concrete structure. 
These devices are referred to herein as support spacers. Prior artisans 
often refer to them as "chairs". 
A very common type of support spacer used to position such reinforcement 
steel mats is comprised of a small concrete block with a length of rebar 
protruding from the concrete, the rebar being bent into an L-shape at its 
free end. These support spacers are placed throughout the concrete 
structure, a first reinforcement steel mat being laid on the concrete 
blocks, and a second reinforcement steel mat being laid upon the L-shaped 
bent portion of the rebar member to hold the second reinforcement steel 
mat parallel to and a distance above the first. 
One problem with the concrete block approach is that the top reinforcement 
steel mat can slide off of the L-shaped rebar member necessitating that 
the top reinforcement steel mat be tied to the L-shaped rebar member with 
a short piece of twisted wire. Having to tie the top reinforcement steel 
mat assembly to each support spacer in a large concrete structure requires 
considerable time and money in view of the high prevailing labor costs. 
Also, twisted wire has a tendency to break under load and the reinforcing 
members are free to move from their intended installed position. 
Another problem with such concrete block spacers is that the lower 
reinforcement mat can slide off the concrete blocks while the concrete is 
being poured. Also, even though the top reinforcement mat is tied to the 
L-shaped rebar, the support spacer can be easily tipped over if the top 
reinforcement mat is located too close to the free end of the bent 
L-shaped rebar member. These conditions will cause the reinforcing members 
to be displaced from their installed and designated positions within the 
concrete structure. If the reinforcing steel layer or mat moves from its 
designated position, the cover concrete thickness above and below the 
reinforcing members is either increased or decreased. Recent studies have 
found that when the steel reinforcement is not positioned properly, 
deterioration of the concrete and reinforcement steel is greatly 
accelerated, especially in concrete roadways and parking structures where 
salt is applied in the wintertime. 
Another critical problem with the concrete block spacer is that concrete 
blocks produce a non-uniform concrete structure. This can lead to stress 
discontinuities between the block and the poured concrete. 
Another example of such a spacer is disclosed in Malsbur U.S. Pat. No. 
2,754,764 entitled "REINFORCED CONCRETE BEAM SUPPORT" which shows a rebar 
with a U-shape bent free end, allowing two wire assemblies to be tied onto 
the bent area and a third assembly to be layered on a concrete base. 
Another type of spacer is disclosed in U.S. Pat. No. 1,772,741 entitled 
"REINFORCING STIRRUP ASSEMBLY" issued to Barber which comprises an 
inverted V-saddle on which a reinforcing assembly rests. 
An inverted "V" spacer with a rebar rod support clip welded to its top is 
disclosed in U.S. Pat. No. 3,114,221 issued to Eriksson entitled 
"BROAD-SUPPORTING CHAIR FOR CONTINUOUSLY REINFORCING CONCRETE PAVING." By 
bending the tabs on the clip, one locks the rebar in place. However, the 
clip can break off the support and seems particularly susceptible to such 
breakage when the clip is bent by foot as shown in the patent. Also, such 
an assembly is expensive to manufacture. 
SUMMARY OF THE INVENTION 
The present invention is a reinforcement support spacer for use in 
supporting and spacing reinforcement members for concrete structures which 
comprises a support having at least one recess therein for receiving a 
reinforcement member and locking means integrally formed in the support 
for positively locking a reinforcement member into the recess. 
In narrower aspects of the invention, the reinforcement support spacer 
locking means comprise barbs or tangs disposed within the recess to permit 
a reinforcing member to be slidably inserted within the recess but to 
prevent the reinforcing member from being pulled from the recess after 
being inserted. 
The reinforcing support spacer of the present invention positively locks 
concrete reinforcing members thereby preventing the reinforcing members 
from floating or from being forced out of their installed position in 
plastic concrete. The spacer of the present invention also prevents 
significant movement of the reinforcement members before, during and after 
pouring of the concrete. Additionally, the reinforcement support spacer of 
the present invention can economically be manufactured from plastic or 
steel. 
Finally, when a plurality of reinforcement support spacers of the present 
invention are used, one or more reinforcement layers can be preassembled 
and positively interlocked to form a reinforcing system, and can be picked 
up and installed as a single unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In a preferred embodiment, support spacer 10 is a two-tier, two-recess 
reinforcement support spacer (FIG. 1) having webs 12a, b, c and d, upper 
recess 13, lower recess 16 and feet 18. Upper recess 13 has opposed barbs 
14 disposed therein to permit a reinforcement member such as reinforcement 
member 100 to be forceably inserted between barbs 14 and into recess 13 
but substantially to prevent reinforcement member 100 from being pulled 
from recess 13. Lower recess 16 has opposed barbs 17 disposed therein to 
permit a reinforcement member 105 to be forceably inserted between barbs 
17 and into recess 16 but substantially to prevent reinforcement member 
105 from being pulled from recess 16. Reinforcement support spacer 10 and 
the reinforcement members 100 and 105 are supported on a horizontal 
surface by feet 18a, b, c (not shown) and d resting firmly on the 
horizontal surface. 
So that reinforcement support spacer 10 can be attached to a mat 100 near 
the intersection of perpendicular mat members 101 and 102, web 12a is 
provided with a shoulder 19 which is below the top of column 11. Web 12a 
is cut away at 11 to permit support spacer 10 to be attached to a lower 
reinforcement mat 105 at the intersection of perpendicular mat members 106 
and 107. To permit a bottom reinforcement member to be inserted into lower 
recess 16, a portion of web 12b is cut away at 15. 
The term "reinforcement" is used to mean steel reinforcement typically used 
to reinforce concrete. There are two general types: reinforcement bars and 
welded wire fabric reinforcement. Two reinforcement mats 52, 52' are shown 
in FIG. 7 as comprising members (53) and members (54) perpendicular 
thereto (using the upper mat for illustration purposes) as part of a 
lattice. The term reinforcement mat refers to a reinforcement grid made up 
of a plurality of reinforcement members in two sets, at right angles to 
each other. In the case of reinforcement bar (rebar) mats, the rebar 
members are most commonly tied with wire at their intersections with each 
other. In the case of welded wire fabric reinforcement mats, the members 
are welded at their intersections. A reinforcement mat 100 is partially 
shown in FIG. 1 as including member 100a and member 100b perpendicular to 
each other. It should be understood that steel bars or welded wire fabric 
can be used in combination with the spacer of the present invention. 
Spacer 10 is molded from plastic. Webs 12a-d radiate outwardly from a 
central vertical axis. Each is also relatively stiff to provide support 
for upper and lower reinforcement 100 and 105 before, during and after 
pouring of the concrete. Each web 12a-d terminates in feet 18a-d, 
respectively. Feet 18a-d engage the form surface upon which spacer 10 is 
placed. 
Unlike webs 12, c, and d, web 12b is discontinuous in two respects. First, 
it includes a top recess 13 located at its top edge, and an intermediate 
recess 16 located intermediate the top and bottom of web 12b. Second, a 
portion of web 12b is cut away at 15. This allows recess 16 to open 
upwardly rather than to the side, and allows one to insert a reinforcement 
member into gap 15 and then downwardly into upward opening recess 16. 
Both recesses 13 and 16 open upwardly. This allows one to force 
reinforcement downwardly into the recesses, using the resistance of the 
surface upon which spacer 10 rests to facilitate applying the downward 
force. If recesses 13 and 16 opened to the side, one would have to oppose 
the insertion of reinforcement into the openings by placing a hand or foot 
against the opposite side of spacer 10. Otherwise the spacer would just 
move in response to the insertion force. 
Each recess 13, 16 is provided with barbs 14 and 17 respectively. FIG. 2 
shows a detailed view of the barbed recess 13 of FIG. 1. This arrangement 
comprises upper opposed barbs 14a, lower opposed barbs 14b and a bottom 
portion 33. Opposed barbs 14a and 14b are each oriented inwardly toward 
the longitudinal axis of recess 13 and are angled toward the bottom 33 of 
the recess at approximately a 30 degree angle to a line normal to the 
longitudinal axis. Barbs 14 are oriented generally inwardly and toward the 
bottom of recess 13 to permit a reinforcement member to be forced 
therebetween to the base 33 of recess 13 and to prevent the reinforcement 
member from being pulled from recess 13 without the application of a great 
force. FIG. 2a shows a detailed view of the barb-recess 13 of FIG. 1 
having a reinforcement member 100a inserted into the recess. It can be 
seen that lower opposed barbs 14b engage reinforcement member 100a and are 
forced outwardly by reinforcement member 100a. Barbs 14b, therefore, hold 
or grip the reinforcement member in recess 13. Barbs 14a primarily lock 
the reinforcement member in the recess, but barbs 14b tend to lock and 
hold as well. 
As indicated above, support spacer 10 is made from plastic. While webs 
12a-d must have a certain stiffness, barbs 14, 17 must have flexibility. 
Hence, the plastic material of spacer 10 should be sufficiently flexible 
such that a reinforcement member can be forced past the barbs into the 
recess, but the plastic should be sufficiently rigid so as to prevent 
substantially a reinforcement member from being pulled outwardly from the 
recess due to the upward force of the concrete as it is being poured. 
Also, the plastic must have sufficient rigidity that webs 12a-d are stiff 
and resist bending under the weight of the reinforcement steel, workers, 
equipment and pouring concrete. It has been found that high density 
polypropylene is a suitable plastic to use. High density polyethylene is 
also acceptable. 
The base 33 of recess 13 has horizontal dimensions at least equal to the 
radius of the largest reinforcing member to be inserted in recess 13. The 
construction of recess 16 and barbs 17 is comparable to that of recess 13 
and barbs 14. The dimensions may differ if recess 16 is intended to 
accommodate a different sized reinforcement member. 
Because recess 13 must be sufficiently deep to accommodate reinforcement 
member 100a as well as barbs 14 located above member 100a, the top of 
spacer 10 must of necessity extend higher than rod 100a resting in recess 
13. If it did not, there would be no upper support for the upper portion 
of web 12b. To make it possible to locate spacer 10 adjacent a transverse 
reinforcement bar or rod 100b, web 12a, which is spaced 90 degrees from 
web 12b, is terminated short of the top the spacer. The top of web 12a 
defines a shoulder 19 spaced below transverse rod 100b. Shoulder 19 should 
be of sufficient depth from the top of spacer 10 such that the top of 
spacer 10 is no higher than the uppermost portions of reinforcement rod 
100b. This ensures that the cover concrete above the reinforcement steel 
will be of substantially uniform thickness from the top of the 
reinforcement assembly (i.e., the reinforcement mat and spacers) to the 
surface of the concrete. 
Web 12a is cut away at 11, defining shoulder 11a, so that it is possible to 
locate spacer 10 adjacent a transverse reinforcement member 107, web 12a 
being spaced 90 degrees from web 12b. 
In use, a first reinforcement mat 105 is laid onto a surface onto which 
concrete is to be poured. At various points along the first reinforcement 
mat lattice, reinforcement spacers 10 are lockably secured by lifting the 
first reinforcement member into cut away portion 15 and pushing 
reinforcement member 106 into lower recess 16 past barbs 17. A second 
reinforcement mat 100 is lifted to the top of reinforcement spacer 10 and 
positioned at the opening of each recess 13. Reinforcement member 100a is 
then forced downwardly past barbs 14 into each recess 13 in each spacer. 
In this manner, the two assemblies will be spaced from each other and from 
the surface on to which concrete is to be poured. Barbs 14 and 17 will 
lock first reinforcement assembly and second reinforcement assembly into 
recesses 13 and 16, respectively, due to the directional orientation of 
the barbs into their respective recesses. 
The support spacers are spaced from each other at a distance both 
longitudinally and transversely as required to support the steel 
reinforcement, the anticipated amount of concrete to be poured onto the 
mat, and the anticipated loads during construction (workers, equipment and 
the like) or on the mats. Typically, the support spacers are spaced four 
feet on center in other direction. 
An alternative recess arrangement is illustrated in FIG. 3. Web 12b 
includes a side opening recess 35a having upper barbs 36a and b and lower 
barbs 37a and b, each pair of barbs meeting at the longitudinal axis of 
recess 35. Note that the barbs touch but are not joined at the 
longitudinal axis. The recess of FIG. 3 is particularly adapted for 
reinforcement members having very small diameters. Barbs 36a and b and 
barbs 37a and b can be manufactured to meet at the longitudinal axis if 
extra force is deemed necessary to retain a reinforcement member within 
recess 35. While recess 35a is a side opening recess, the principle of 
barbs which meet at their ends could also be used in an upwardly opening 
recess. 
An alternative embodiment of the two-tier, two-recess reinforcement support 
spacer described above is shown in FIG. 4. The reinforcement support 
spacer 20 shown in FIG. 4 comprises a column 21, webs 22a, b, c and d, 
upper recess 23, lower recess 26 and feet 28. Upper recess 23 has barbs 
24, and lower recess 26 has barbs 27. Upper recess 23 and lower recess 26 
are oriented so that their longitudinal axes are perpendicular to the 
longitudinal axis of reinforcement spacer 20. The reinforcement members 
are forced sideways into recesses 23 and 26. Notch 27a is provided to 
allow support spacer 20 to be positioned at the intersection of two 
perpendicular bars or rods on a lower reinforcement member. Shoulder 25 is 
provided to permit spacer 20 to be positioned at the intersection of two 
perpendicular bars or rods on an upper reinforcement member. 
One advantage to the side opening two-tier, two-recess reinforcement spacer 
shown in FIG. 4 is that notch 27a can be made smaller than the 
corresponding notch 11 on reinforcement spacer 10. Notch 11 must be made 
larger to allow the vertical movement of reinforcement mat member 105 as 
it is being inserted into cutaway portion 15 and pushed downwardly into 
recess 16. By contrast, the reinforcement member inserted into recess 26 
need only be moved horizontally. Therefore, notch 27a is smaller. Because 
notch 27a is smaller, web 22a is stronger than web 12a. 
The addition of column 21 to alternative embodiment 20 gives spacer 20 
additional strength and stiffness vis-a-vis spacer 10. Where heavier 
reinforcement is used, or where heavier loads on the reinforcement are 
anticipated, the additional strength offered by column 21 might be 
desirable. 
Also shown in FIG. 4 is a base 29 on which feet 28 rest and to which they 
are secured. Base 29 is provided with slots 29a, c, d into which feet 28a, 
b, c and d are inserted in a snap-fit engagement. A base 29 should be used 
when it is desired to use the two-level reinforcement spacer of the 
present invention on-grade. In other words, when pouring concrete on-grade 
as opposed to above grade where flat horizontal forms are used, a base 29 
should be added to distribute the weight carried by feet 28 over a wider 
area. Base 29 should not be considered as applicable only to a spacer 
having side-opening recesses shown in FIG. 4. In any event, it is easy to 
convert the support spacer from an above grade to a on-grade support 
spacer merely by snapping on or removing base 29 as described above. 
Base 29 also has another advantage. The concrete being poured will weigh 
down upon base 29. This weight will oppose the upward force exerted by the 
rising concrete against reinforcement members and prevent the 
reinforcement members from floating in the concrete. 
Base 29 could be integrally molded with webs 28a-d and central column 21. 
In that case, said webs and column would extend all the way to base 29, 
eliminating any opening between the bottom and of column 21 and base 29. 
Spacer 20 as shown thus has several features differing from those of spacer 
10. The showing of same in one spacer, i.e., 20, is not intended to imply 
that they must of necessity be used in conjunction. They could be used 
independently of one another in various alternatives to spacers 10 and 20 
as shown. 
A third embodiment of the present invention, a two-tier reinforcement 
support spacer 110 is shown in FIG. 4a. It comprises barbed recesses 113 
and 114 on a web 118b. A shoulder 119 and a notch 111a are provided on a 
web 118a to accommodate transverse reinforcement members on reinforcement 
mats having members inserted into recesses 113 and 114, respectively. 
These features are substantially identical to the corresponding features 
of the embodiment shown in FIG. 1. 
The embodiment shown in FIG. 4a is specifically designed for heavier 
loading than the embodiment of FIG. 1. To accommodate heavier loads, web 
118d is provided with reinforcement ribs 120 and a large reinforcement 
bead 121. Reinforcement ribs 120 are projections integrally formed in web 
118d, extending along the longitudinal length of web 118d, and located 
between the juncture of the four webs 118 and bead 121. In most 
applications, ribs 120 and bead 121 are probably not necessary in 
conjunction, but rather will typically be alternatives. Bead 121 is 
cylindrically shaped and extends along the longitudinal length of web 118d 
at the outer edge thereof. Bead 121 is also integrally formed with web 
118d. 
It has been found that for particularly large loads, for instance, many 
construction workers standing on the upper reinforcement mat, the support 
spacer made from plastic will have a tendency to bend about the center at 
or slightly above the lower recess 114 in the general direction of the 
arrow shown in FIG. 4a stretching web 118d. This bending movement can be 
resisted by thickening web 118d either with the reinforcement ribs 120 or 
the reinforcement bead 121, or both. It should be evident that thickening 
web 118d longitudinally with reinforcement ribs 120, reinforcement bead 
121 or some other thickening structure will increase the force necessary 
to stretch web 118d when the moment exerted on recess 113 is applied. 
Reinforcement ribs 120 and reinforcement bead 121, of course, are merely 
illustrative of the types of strengthening means which can be employed. 
Base 129 is circular and has been modified to increase the resistance of 
the support spacer 110 to tipping over from the moment applied in recesses 
113, 114. As shown, support spacer 110 can be eccentrically mounted on 
base 129 so that web 118b is directly over the center of base 129. Thus, 
there is a distance R from the center of the base 129 to the edge thereof 
which acts as a lever arm to resist tipping of the support spacer 110, the 
support spacer 110 being fixedly secured to base 129 in a manner to be 
described. 
Base 129 also includes thickening ribs 130a-d. Each of the thickening ribs 
extends radially outwardly from each of the feet 131a-d of reinforcement 
support spacer 110. Thickening ribs 130a-d join at a common center offset 
from the center of base plate 129 to form a cross-shaped pattern on base 
plate 129. Thickening ribs 130a-d are integrally formed with base plate 
129. Thickening ribs 130 are provided to reinforce the base plate 129 
where it is necessary. This represents a savings of material from having 
to have a uniformly thick base plate 129. A uniformly thick base plate 
would involve reinforcing portions of base 129 which do not need to be 
reinforced. 
Base plate 129 can be integrally formed with reinforcement support spacer 
in the same injection mold. Alternatively, it is possible to have 
reinforcement support space 110 engage base plate 129 in a snap-fit 
relationship as shown in FIG. 4b. Each of the feet 131 can, therefore, be 
provided with projections which engage holes in thickening ribs 130. 
Several other modifications can be made to the embodiment of FIG. 1 as 
shown in FIG. 4a. First of all, feet 131b and d can be flared outwardly 
and downwardly, as indicated at 133 and 133'. If base plate 129 is snapped 
onto reinforcement support spacer 110, having flares 133, 133'prevents 
feet 131 from penetrating too far into base plate 129. As shown in FIG. 
4b, for instance, if flare 133 is wider than hole 129b into which foot 
131b is inserted, foot 131b cannot penetrate downwardly past flares 133 
into base plate 129. 
Additionally, reinforcement support spacer 110 has webs 118a and c which 
are thinner than, and which project a shorter distance outwardly from the 
longitudinal axis of the reinforcement support spacer, than webs 118b and 
118d. This represents a savings of material over the embodiment shown in 
FIG. 1. Finally, as shown in FIG. 4c, each of the barbs in recesses 113, 
114 can be narrowed as shown to provide more resiliency if desired. When 
narrowing the barbs 135 as shown, it is desirable to take away the 
material from only one side of web 118b. If the reinforcement support 
spacer 110 is injection molded with the parting line of the molds being 
parallel to and across webs 118b and 118d, narrowing barbs 135, as shown 
in FIG. 4c, means that only one of the two mold halves need to be machined 
to provide cavities for barbs 135. 
The embodiments of FIGS. 1, 4 and 4a can conveniently be injection molded. 
In fact, a mold can be constructed for manufacturing a reinforcement 
spacer having more than two recesses. Mold inserts can be inserted into 
the mold so that a two or even a one-recess reinforcement spacer can be 
manufactured from the same mold. 
A fourth embodiment of the present invention, a single tier reinforcement 
support spacer 40 is shown in FIG. 5. Reinforcement spacer 40 comprises a 
web 41 having a recess 42 therein, recess 42 having barbs 43 for lockably 
gripping a reinforcement member which can be forced downwardly past barbs 
43 into the bottom of recess 42. Web 41 is fixedly secured to and 
perpendicular with a base 44 which rests upon a surface onto which 
concrete is to be poured. The embodiment of FIG. 5 is used for spacing a 
single reinforcement assembly above a surface in contrast with the 
embodiments illustrated in FIGS. 1 and 4 which space two reinforcement 
assemblies above a surface. The embodiment of FIG. 5 is particularly well 
suited for on-grade applications because base 44 provides a large surface 
area onto which web 41 and the reinforcement assembly inserted into recess 
42 can rest. In other words, the weight of the reinforcement assembly is 
distributed over the entire area of base 44. Base 44 also acts to prevent 
the upward movement of the reinforcement member when concrete is poured 
because the concrete as it is poured will weigh down the top surface of 
base 44. 
Recess 42 and barbs 43 of reinforcement spacer 40 can have the proportional 
dimensions of either of the recesses illustrated in FIGS. 2 and 3. As 
indicated above, the length of barbs 43 and the diameter of the rounded 
portion of the bottom of recess 42 is dependent upon the diameter of the 
reinforcement member to be forceably inserted into recess 42. 
As shown in FIG. 6, the reinforcement support spacer of the present 
invention can also be made from sheet metal. FIG. 6 illustrates a support 
spacer 60 having sidewalls 61, 61', a bottom wall 62 and a top wall 63 
intermediate the tops of sidewalls 61, 61'. Recesses 65, 65' are provided 
for lockably receiving a lower reinforcement member. At the tops of 
sidewalls 61, 61', recesses 64, 64' are provided for lockably receiving a 
top reinforcement member. A gap 68 is provided across the top wall 63 to 
permit the upper reinforcement member to be inserted into recesses 64, 64' 
through the top of support spacer 60. 
Locking tines 66, 66' depend downwardly from top wall 63 as shown in FIG. 6 
to lock an upper reinforcement member into recesses 64, 64'. As shown in 
detail in FIG. 6a, locking tines 66 comprise a pair of locking tines 66a 
and 66b. It should be understood that even though locking tines 66 are 
illustrated in FIG. 6a, locking tines 66' are identical therewith so 
reference will be made only to locking tines 66. Note that the tines on 
one side of gap 68 are staggered from the tines on the other side of gap 
68. This is done because the tines are stamped out of the top wall forming 
gap 68. In order to make the tines as long as possible, they must be 
staggered as their maximum length is equal to the width of gap 68. 
Locking tines 66 are each oriented inwardly toward the longitudinal axis of 
recesses 64, 64' and are angled toward the bottom of the recesses. Locking 
tines 66a, 66b must have flexibility such that after a reinforcement 
member is forced past the locking tines into the recess as shown in FIG. 
6a, the tines will substantially return to their original positions 
thereby locking a reinforcement member 200 into recesses 64, 64'. 
The configuration of locking tines 67, 67' for bottom recesses 65, 65' is 
somewhat different from the configuration of tines 66, 66'. However, they 
function the same way. Locking tines 67, 67' are identical to each other; 
locking tines 67' are illustrated in FIG. 6b. Each locking tine 67' 
includes a horizontal tine support 67a' which is formed integrally with 
sidewall 61' and projects inwardly into the spacer as shown in FIG. 6 
along upper and lower horizontal edges of recess 65'. Extending inwardly 
toward the longitudinal axis of recess 65' from tine supports 67a' are 
opposed locking tines 67b'. Tines 67b' are angled toward a bottom 65a' of 
recess 65'. 
Locking tines 67b' are sufficiently resilient such that after a 
reinforcement member 201 is forced past the locking tines, the locking 
tines will return substantially to their original positions thereby 
locking reinforcement member 201 into recess 65' as shown in FIG. 6b. 
Reinforcement support spacer 60 is easily manufactured by stamping recesses 
64, 64' and a slot constituting a gap 68, recesses 65, 65' in a strip of 
metal, tines 66, 66' and tines 67, 67' being stamped in the same process. 
The strip of metal is then bent in a trapezoidal shape in a conventional 
stamping process with a fold 68 being formed integrally with the bottom 
wall 62 and engaging the bottom portion of sidewall 61 thereby preventing 
the bottom of the sidewalls 61, 61' from spreading apart. No welding is 
required to secure fold 68 to the bottom of sidewall 31, though it could 
be advantageously utilized as an added securement, if desired. Fold 68 
acts as a hook which prevents sidewalls 31, 31' from separating under the 
weight of the reinforcement mat members inserted into recesses 64, 64' and 
65, 65'. 
Lightening holes 69, 69' can be stamped into sidewalls 61, 61' to permit 
concrete to flow therethrough. When the concrete solidifies in the holes, 
it forms a bridge of concrete between the concrete inside the spacer and 
the concrete outside the spacer thereby strenthening the concrete 
structure by arresting shear stresses which may develop along the planes 
of walls 61, 61'. Any shear stress developed along these walls would by 
necessity have to fracture the concrete bridges formed in lightening holes 
69, 69'. 
One of ordinary skill in the art will recognize that the embodiment shown 
in FIG. 6 is an adaptation of the spacer disclosed in my co-pending patent 
application Ser. No. 571,566 filed Jan. 26, 1983, entitled REINFORCEMENT 
SUPPORT SER. That application is expressly incorporated herein by 
reference. 
One advantage in the reinforcement support spacer of the present invention 
is that a reinforcement assembly can be preassembled at a factory or on 
the construction site. Depending upon the transportation costs, 
preassembly at the factory can result in significant labor cost savings 
considering the rather high prevailing wages of on-site construction 
workers. 
Such preassembly can be done with a single-level spacer illustrated in FIG. 
5. If a reinforcement mat is used, for instance, a plurality of 
reinforcement spacers 40 can be secured to the mat at various points on 
the mat in the factory so that when the mat is shipped to the construction 
site, the mat can be lowered onto the surface onto which concrete is 
poured with the reinforcement spacers 40 preattached. Care should be taken 
in ensuring that the bases 44 of reinforcement spacers 40 are oriented 
toward said surface before concrete is poured. 
Preassembly of the reinforcement assembly is particularly advantageous when 
the two-tier spacer of FIGS. 1, 4 or 6 is used. As indicated in FIG. 7, a 
reinforcement mat assembly 50 preassembled at a factory or on the job site 
comprises an upper mat 52 and a lower mat 55 lockably and spacedly secured 
to each other by spacers 10. Spacers 10, of course, can have the features 
of the spacers illustrated in FIGS. 1, 4 or 6, though spacer 10 of FIG. 1 
is specifically shown. The advantage to preassembling reinforcement mat 
assembly 50 at a factory is that the mat assembly can be picked up by a 
crane (not shown) by hooks 58 secured to lower mat 55 or upper mat 52. By 
hooking on the lower mat 55, one of the cross wires or length of rebar 
will be lifted against the upper edge of recess 111a, to thereby prevent 
either the upper mat 52 or lower mat 55 from being pulled out of 
engagement with their retaining barbs 135. In this manner, the entire 
assembly can be lowered onto the surface onto which the concrete is to be 
poured with the mats and spacers oriented in the proper directions. 
The reinforcement spacer of FIG. 6 is also well adapted to preassembly of 
reinforcement mats. A plurality of reinforcement support spacers 60 can be 
lockably secured to a lower reinforcement mat by locking the reinforcement 
support spacer to a member of the lower reinforcement mat by insertion of 
that member into the corresponding lower recesses on each spacer past the 
locking tines therein. An upper reinforcement mat can be placed over the 
first by inserting an upper reinforcement mat member into the 
corresponding upper recesses on the reinforcement support spacers. The 
second reinforcement mat will be locked to the spacer by the locking tines 
in the upper recesses. By "corresponding recesses " it is meant that each 
reinforcement set is inserted into recesses spaced vertically from one 
another on each of the support spacers such that each reinforcement set is 
spaced from and generally parallel to other reinforcement sets. 
It should be apparent that the present invention is also not restricted to 
a one or two-level spacer. It is possible, consistent with the teachings 
of the present invention, to construct a spacer having more than two tiers 
or recesses. It should also be apparent that a spacer with more than two 
levels can be preassembled and shipped to the construction site in a 
manner such as that described above. 
The reinforcement spacer of the present invention provides excellent 
tolerances between the top and bottom reinforcement mats, between the 
surface of the concrete and the top of the reinforcement assembly and 
between the bottom of the bottom reinforcement layer and the bottom of the 
concrete. As noted above, the barb-type locking means lockably secures 
reinforcement members within the recesses. Therefore, as the concrete is 
poured around the reinforcement members and the spacers onto a horizontal 
surface, the reinforcement members cannot float out of the recesses due to 
the locking action of the barbs. Thus, the tolerances can be held within 
fairly narrow, desirable ranges. Narrow tolerance ranges are highly 
desirable because recent studies suggest that much corrosion of 
reinforcing steel in concrete structures is due to steel floating within 
the concrete as the concrete is being poured, frequently floating fairly 
close to the surface of the cover concrete where cracks will form or 
concrete will break away, creating areas where electrochemical corrosion 
reactions can occur on the reinforcement steel, especially werein deicing 
salt is used. This corrosion substantially weakens the structural 
integrity of the concrete structure and hastens its deterioration. 
When the reinforcing steel is held within close tolerance to its designated 
position within the concrete structure, cracking of the concrete can be 
greatly reduced, minimizing the deterioration of the concrete and 
reinforcing steel. 
The reinforcement spacer described above also prevents significant 
horizontal movement of reinforcement members before, during and after 
pouring of the concrete because the feet on the base of the reinforcement 
spacer of FIG. 1 or 4 or the bases on the spacers of FIGS. 4, 5 or 6 
straddle a sufficient area whereby tipping of the reinforcement spacer is 
difficult. Because the barbs 14b can grip reinforcement members of 
sufficient diameter, horizontal movement of the reinforcement members 
within the barbed-recesses of the above embodiments is difficult. 
Of course, it is understood that the above is merely a preferred embodiment 
of the invention and that various changes and alterations may be made 
without departing from the spirit and broader aspects of the invention.