Bolster for use in construction

A bolster for use in construction including a plurality of leg members arranged in parallel relationship and a beam integrally formed with the plurality of leg members and extending across the plurality of leg members. Each of the plurality of leg members has a foot for contacting an underlying surface. Each of the leg members includes a central body portion, a first leg extending downwardly from one side of the central body portion and a second leg extending downwardly from an opposite side of the central body portion. The foot is formed at an end of each of the first and second legs opposite the central body portion. The foot includes a plurality of pin-like projections extending outwardly from a bottom surface thereof. The beam has a waveform pattern formed across a top surface of the beam and a rectangular cross-section in a plane parallel to the plurality of leg members. The beam includes a male connector formed at one end and a female connector formed at an opposite end for receipt within a connector of an adjacent bolster.

TECHNICAL FIELD 
The present invention relates generally to bolsters, chairs, and spacers 
that are used in construction activities for the support of post-tension 
cables, rebars, or mesh. More particularly, the present invention relates 
to bolsters which are preformed for the support of rebars in deck 
construction activities. 
BACKGROUND ART 
Bolsters are commonly used in the construction industry for the support of 
post-tension cables, rebars, or mesh above a surface. Typically, when such 
materials are used, they must be supported above the surface when the 
concrete is poured. These bolsters are used with poured decks. In normal 
use, the bolster is positioned on the deck and includes a beam which 
extends across a plurality of leg members. This beam is formed so as to 
contact and support the rebar while the base of the bolster rests on the 
deck or on a grade. When the concrete is poured, the bolster will support 
the rebar a proper distance above the bottom surface. 
In normal use, such bolsters are preformed so that they can be installed 
quickly and easily upon the deck. Conventionally, the preformed bolster 
will have a plurality of leg members and a steel rod welded to a top 
surface of each of the leg members. The rod will serve as a receiving area 
for the rebar. Conventionally, these bolsters are formed in preset 
lengths. If it is necessary to extend the bolster across a long surface of 
the deck, then the ends of the beams of adjacent bolsters will be wired 
together such that the bolsters are in an end-to-end relationship. 
The most common bolster that is employed is a metal bolster manufactured by 
Meadow Steel Products of Tampa, Fla. This bolster has a plurality of 
inverted U-shaped leg members having outwardly extending foot portions. A 
rigid tubular rod having a slight waveform pattern formed thereon is 
welded to the middle of the inverted U-shaped leg members. Each of the leg 
members is generally arranged in parallel relationship to each other. The 
feet of each of the leg members will rest on the deck while the rebar is 
supported. After the concrete has solidified, and the deck is removed, the 
bottom surfaces of the feet will be exposed. As such, it is necessary to 
coat the feet with an anti-rust material. Alternatively, stainless steel 
material can be employed for the leg members and their associated feet. 
Corrosion and cost are major problems affecting the bolster of Meadow Steel 
Products. In order to form such a bolster, a great deal of manufacturing 
must take place, including metal forming, bending, dipping, and welding. 
These activities, along with the cost of the material used to form the 
bolster, make the cost of the bolster relatively expensive. If the bolster 
is not coated or made of a stainless steel material, then corrosion can 
adversely affect the product. This corrosion can even occur when the metal 
is coated. 
In the past, various attempts have been made to create bolsters of plastic 
material that can serve the purposes of the bolster of Meadow Steel 
Products. In general, such efforts have resulted in plastic chairs that 
are ineffective, cumbersome to use, or unable to properly withstand the 
forces imparted by the rebar upon the bolster. One such plastic bolster, 
manufactured by Conac, includes a central beam which is integrally formed 
with a plurality of leg members. Each of the leg members extends 
downwardly so as to present a flat surface to the underlying deck. No feet 
are provided which allow the bolster to be stapled to the deck. 
Additionally, the configuration of this Conac bolster allows for easy 
deformation. It is very difficult and time consuming to join lengths of 
the Conac bolster together. The Conac bolster also lacks the suitable wave 
form pattern for the receipt of the rebar on the top surface of the 
bolster. This plastic bolster is often broken, collapsed, or tipped over 
in actual use. The base of such a bolster has only a very small area of 
contact with the deck. As such, these plastic bolsters lack the strength 
and ability to withstand the loads imparted to them. 
It is an object of the present invention to provide a bolster that is 
corrosion-proof and relatively inexpensive. 
It is another object of the present invention to provide a bolster that can 
be easily connected in end-to-end relationship. 
It is a further object of the present invention to provide a bolster that 
withstands the forces imparted on it. 
It is still another object of the present invention to provide a bolster 
that facilitates the ability to staple the bolster to the deck. 
It is still another object of the present invention to provide a bolster 
that is easy to manufacture and easy to use. 
These and other objects and advantages of the present invention will become 
apparent from a reading of the attached specification and appended claims. 
SUMMARY OF THE INVENTION 
The present invention is a bolster for use in construction that comprises a 
plurality of leg members arranged in parallel spaced relationship and s 
beam which is integrally formed with the plurality of leg members. 
Each of the plurality of leg members has a foot means extending outwardly 
therefrom for contacting an underlying surface. The beam extends 
transversely across the plurality of leg members. Each of the leg members 
includes a central body portion, a first leg extending downwardly from one 
side of the central body portion, and a second leg extending downwardly 
from an opposite side of the central body portion. The foot is formed at 
an end of each of the first and second legs opposite the central body 
portion. The foot includes a first foot which is formed at the end of the 
first leg and extends outwardly horizontally therefrom. The first foot has 
a top surface and a bottom surface. A second foot is formed at the end of 
the second leg and extends horizontally outwardly therefrom. The second 
foot also has a top surface and a bottom surface. The bottom surface of 
the first foot has a plurality of pin-like projections extending outwardly 
therefrom. The bottom surface of the second foot also has a plurality of 
pin-like projections extending outwardly therefrom. The top surface and 
the bottom surface are in parallel relationship to each other. 
The central body portion has a generally rectangular cross-section in a 
plane aligned with the beam. The beam is integrally formed with the 
central body portion so as to extend across this rectangular 
cross-section. The beam has a waveform pattern formed along the top 
surface of the beam. The beam has a rectangular cross-section in a plane 
parallel to the plurality of leg members. The beam has a height which is 
approximately twice a thickness of the beam. The beam is a longitudinal 
member having a male connector formed at one end and a female connector 
formed at an opposite end. The male connector is of a conical 
configuration suitable for receipt within a female connector, of 
frustoconical configuration, of an adjacent beam. The female connector has 
a conical interior opening extending so as to narrow at a bottom of the 
female connector. The conical male connector has a configuration suitable 
for mating receipt within the conical interior of the female connector. A 
slot is formed in the female connector such that the beam of the male 
connector can extend therethrough in alignment with the beam extending 
from the female connector. The slot is formed adjacent the top of the 
female connector approximately 180.degree. from the beam. 
In the present invention, the plurality of leg members and the beam are 
integrally formed of a polymeric material.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, there is shown at 10 the bolster in accordance with 
the preferred embodiment of the present invention. The bolster 10 includes 
a plurality of leg members 12, 14 and 16 which are arranged in parallel 
spaced apart relationship. A beam 18 is integrally formed with the 
plurality of the leg members 12, 14, and 16 and extends transversely 
across these leg members. 
In FIG. 1, it can be seen that the leg member 12 includes a bottom surface 
20 and a pin-like projection 22 extending downwardly therefrom. The 
pin-like projection 22 extends downwardly from the bottom surface 20 so as 
to engage in underlying surface, such as a deck. The use of the pin-like 
projections 24 greatly enhances the strength of the leg members 22 since 
much of the strong supporting force of the leg members 12 is transferred, 
through the pin-like projections 22, to the underlying surface. The use of 
such pin-like projections 22 resists deformation of the leg members when a 
load is placed upon the beam 18. As used herein, the term pin-like 
projections refers to such projections in the form of pins, inverse 
pyramidal projections, or similar projections which can "bite" into an 
underlying surface. 
In FIG. 1, it can be seen that the leg member 12 extends upwardly from the 
bottom surface 20 so as to receive the beam 18 therein. A top surface 24 
is formed opposite the bottom surface 20 as part of the foot of the leg 
member 12. The top 26 of the leg member 12 is adjacent to the top surface 
28 of the beam 18. Each of the legs 12, 14, and 16 has a similar 
configuration. The legs 12, 14, and 16 are generally evenly spaced along 
the length of the beam 18. 
The beam 18 has a waveform pattern formed along the top surface 28 of beam 
18. This waveform pattern 28 is suitable for the receipt of rebar therein. 
These "waves" act as a receiving area for such materials. The beam 18 has 
a flat bottom surface 30. 
As can be seen, the beam 18 is a longitudinal member that has a male 
connector 32 at one end and a female connector 34 at the opposite end. The 
male connector 32 is suitable for receipt within a female connector (such 
as 34) of an adjacent beam. In normal use, this configuration of male 
connector 32 and female connector 34 allows several of the bolsters 10 to 
be connected to one another in end-to-end relationship. As such, the 
bolsters 10 can be connected to one another without the need for wiring 
together. 
FIG. 2 illustrates, with particularity, the leg member 14. It can be seen 
that the leg member 14 includes a central body portion 36, a first leg 38, 
a second leg 40, a first foot 42, and a second foot 44. The first leg 38 
extends downwardly from one side of the central body portion 36. The 
second leg 40 also extends downwardly from an opposite side of the central 
body portion 36. The foot 42 is formed at an end of the first leg 38 
opposite the central body portion 14. Similarly, the foot 44 is formed at 
an end of the second leg 40 opposite the central body portion 16. The 
first foot 42 extends horizontally outwardly from the first leg 38. The 
second foot 44 also extends horizontally outwardly from the second leg 40. 
It can be seen that the first foot 42 has a top surface 46 and a bottom 
surface 48. The top surface 46 is in parallel relationship to the bottom 
surface 48. In normal use, the top surface 46 should be spaced from the 
bottom surface 48 by no more than 1/4 inch. As such, this horizontally 
outwardly extending foot 42 facilitates the ability to staple the leg 
member 14 to an underlying surface, such as a deck. The pin-like 
projections 50 extend outwardly from the bottom surface 48 of the foot 42. 
The second foot 44 and the projections 52 have a similar configuration to 
that of the first foot 42. As such, the leg member 44, of the present 
invention, facilitates the ability to properly staple the leg member 14 to 
the underlying surface. In FIG. 2, it can be seen that the beam extends 
transversely across the central body portion 36. The central body portion 
36 has a rectangular cross-section at the intersection with the beam 18. 
The beam 18 will similarly have rectangular cross-section in a plane 
parallel to the plurality of leg members. It can be seen in FIG. 2 that 
the beam 18 has a height which is approximately twice the thickness of the 
beam. As can be seen in FIG. 2, the beam 18 has a height of approximately 
0.4 inches and a thickness of approximately 0.2 inches. This relation of 
height to thickness enhances the load-bearing capacity of the beam 18. As 
such, although the bolster 18 is made of a polymeric material, the sizes 
and dimensions enhance the strength and stability of the bolster 10. In 
FIG. 2, it can be seen that when a load is placed upon the beam 18, the 
projections 50 and 52 will tend to resist any deformation by the legs 38 
and 40. The projections 50 and 52 will serve to "bite" into the underlying 
surface so as to resist such deformation. Since the beam 18 is integrally 
formed, through an injection molding process, with the leg member 14, the 
configuration of the present invention eliminates the need for welding or 
mechanical attachment techniques. 
In FIG. 3, it can be seen that the beam. 18 is a longitudinal member which 
extends for the length of the bolster 10. The first leg member 12 extends 
outwardly transverse to the beam 18. The first leg member 12 includes a 
foot 60 on one side of the beam 18 and a foot 62 on an Opposite side of 
the beam 18. Projections 22 extend outwardly from the bottom surfaces of 
the feet 60 and 62. In the embodiment of the present invention shown in 
FIG. 3, a total of three pin-like projections 22 extend outwardly from the 
bottom surface of the feet 60 and 62. It is possible for fewer projections 
or more projections to be incorporated onto the feet 60 and 62. Similarly, 
the leg member 14 has a first foot 42 and a second foot 44 extending 
transversely outwardly of the beam 18. The projections 50 and 52 are shown 
as extending outwardly of the feet 42 and 44, respectively. The leg member 
16 has a similar configuration to that of the leg members 12 and 14. It 
can be seen in FIG. 3 that the leg members 12, 14, and 16 are arranged in 
plane parallel relationship to each other. 
Importantly, in FIG. 3, it can be seen that the beam 18 has a conical male 
connector 32 at one end and a frustoconical female connector 34 at an 
opposite end. The male connector 32 has a length approximately equal to 
the height of the bolster 10. The male connector 32 is integrally formed 
with the beam 18. The conical male connector 32 extends and tapers 
downwardly so as to have a narrow end aligned with the feet of the bolster 
10. 
With reference to FIGS. 1 and 3, it can be seen that the female connector 
34 has e generally frustoconical configuration. The female connector 34 
includes an interior passage 35 of a conical configuration, generally 
matching the conical configuration of the male connector 32. This interior 
passage 35 opens at the top 37 of the female connector 34 so as to allow 
for the easy receipt of a male connector from an adjacent bolster. A slot 
39 is formed in the female connector 34 adjacent to the top 37. The slot 
39 allows the beam of an adjacent bolster to extend through the slot after 
the male connector is received within the interior passage 35. The slot 39 
is positioned approximately 180.degree. from the beam 18. By inserting the 
adjacent bolster into the female connector proper longitudinal alignment 
is assured between the beam of an adjacent bolster and the beam 18 of 
bolster 10. As a result, lengthy bolster arrangements can be achieved by 
joining separate bolsters in this manner. 
FIG. 4 illustrates the manner in which a male connector 70 of an adjacent 
bolster 72 is received within the female connector 34 of bolster 10. As 
can be seen, the male connector 70 is of a conical configuration similar 
to that of the male connector of the bolster 10. The male connector 70 is 
inserted into the interior passage 35 of the female connector 34. The beam 
74 of the bolster 72 is connected to the male connector 70 and extends 
through the slot 39 of the female connector 34. The top of the male 
connector 70 is generally aligned with the top 37 of the female connector 
34. Beam 18 extends outwardly from the female connector 34. In the 
configuration illustrated in FIG. 4, the beam 74 will be longitudinally 
aligned with the beam 18. This arrangement of male/female connectors 
facilitates the ease of assembly and installation. It is only necessary to 
insert the male connector 70 into the female connector 34, rotate the beam 
74 until it is received within the slot 39 and then press the male 
connector 70 so it resides within the passage 35 of the female connector 
34. The frictional engagement between the male connector 70 and the female 
connector 34 assures a solid connection between the bolster 72 and the 
bolster 10. 
FIG. 5 is a top view of the female connector 34. It can be seen that the 
female connector 34 has beam 18 extending outwardly therefrom. The top of 
the female connector 34 has a circular configuration. The slot 39 is 
formed in one of the walls of the female connector 34 so as to communicate 
between the interior passage 35 and the exterior 80 of the female 
connector 34. The interior passage 35 will taper downwardly in a conical 
manner. 
The bolster 10 of the present invention greatly facilitates the 
installation and use of such bolsters at the construction site. Since each 
of the bolsters includes male/female connectors, it is a relatively easy 
process to connect such bolsters in end-to-end relationship. Since the 
present invention is manufactured through an injection-molding process, 
each of the bolsters 10 is relatively inexpensive and corrosion-proof in 
comparison with conventional metal bolsters. The use of such plastic 
bolsters eliminates the problems of corrosion or discoloring that can 
occur through the use of such metal bolsters. The use of the projections 
at the bottom of the feet and the dimensioning of the beam and leg members 
greatly enhances the strength of the bolster system. The configuration of 
the feet allows the bolster to be stapled to the deck during the 
installation process. 
The foregoing disclosure and description of the invention is illustrative 
and explanatory thereof. Various changes in the details of the illustrated 
configuration can be made within the scope of the appended claims without 
departing from the true spirit of the invention. The present invention 
should only be limited by the following claims and their legal 
equivalents.