Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BASE MOLD FOR CONCRETE POST
FIELD OF THE INVENTION
The present invention relates to a mold and more particularly, to a mold
suitable
for forming a base for concrete posts.
BACKGROUND OF THE INVENTION
Concrete inground posts are installed to serve as supports for exterior
structures
such as decks, porches and out buildings. In a manner similar to a house
foundation, they
require a footing or base in order to disperse the downward force placed upon
them, to
stabilize them to lateral stress and in some areas to retard the action of
frost heaving them
upwardly.
In the art, it is a conventional practice to use a form for the posts and
which form
provides a round hollow manufactured paper or fiber tube. These 12' long fiber
or paper
tubes come in different diameters such as 6", 8" 10" etc. and are cut to the
length required
by the user.
A single manufactured 8" tube may in fact be 71h", 73/4 ", 8" or 8'/4" in
diameter, to
facilitate compact shipping by placing 7'/2" tubes within 73/4" tubes witr~in
8" tubes, etc.
Any base mold to be attached to a section of one of these tubes must therefore
be
either custom fitted to the tube on hand or have the ability to adapt to
v~~rious diameters.
The present practice is that the user will build a custom fitted mold for the
base from
wood. Thus it is well known for builders to construct a square of lumber and
subsequently a plywood top is added. A hole is cut in the plywood to
accommodate the
tube and the box and tube are nailed together. The tube and box are them
placed in the
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excavation and the excavation is subsequently back filled. Frequently
reinforcing rods are
placed in the tube and then the tube and the base are filled with concrete to
provide a one
piece concrete post and base (footing).
There are disadvantages to the above arrangement.
It is a very time consuming process and the joint formed where the tube meets
the
base tends to be somewhat weak when subjected to lateral stress at the abrupt
90° tube to
box joint. A multitude of tools and some skill are required for box
fabrication.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a mold for a base for
concrete
posts which is lightweight, strong and adaptable to various diameter tubes.
It is a further object of the present invention to provide a mold for a base
for a
concrete post having a strong tapered tube to base joint.
It is a further object of the present invention to provide a mold for a base
for a
concrete post which is fast, economical, easy to use and requires no special
tools or skill
to install.
In one aspect of the present invention, there is provided a mold suitable for
forming a base for a concrete post, the mold comprising a mold member having a
side
wall portion and a top wall portion, the top wall portion having means for
forming a
plurality of radially extending main slits extending from a central point to
thereby form a
plurality of flaps, the top wall portion being formed of a flexible material.
In a further aspect of the present invention, there is provided a mold
suitable for
forming a base for a concrete post, the mold comprising a mold member having a
side
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wall portion and a top wall portion, the top wall portion having a plurality
of radially
extending main slits extending from a central point to thereby form a
plurality of flaps, the
top wall portion being formed of a flexible material.
In a still further aspect of the present invention, there is provided a setup
for
pouring a concrete post, the setup comprising a mold having a side walll
portion and a top
wall portion, the top wall portion having a plurality of radially extending
main slits
extending from a central point to thereby form a plurality of flaps, the top
wall portion
being formed of a flexible material, a tube extending upward from the mold,
the flaps
lying adjacent the tube, tabs underneath the tube and retaining the tube in
position.
In a still further aspect of the present invention, there is provided a method
of
pouring a concrete post, the method comprising the steps of providing a mold
having a
side wall portion and a top wall portion, the top wall portion being of a
flexible material
having a plurality of radially extending main slits extending from a central
point to
thereby form a plurality of flaps, a plurality of alignment tabs associated
~,vith the flaps,
inserting the tube through the top wall portion to thereby extend the flaps.
engaging the
alignment tabs with the tube to thereby align the tube to 90° to the
base mold, affixing the
flaps to the tube, placing the mold and the tube on a substrate, and pouring
concrete in the
tube to form a post having an integral base formed therewith.
In greater detail, the mold of the present invention is adapted for use with
tubes
which in turn act as molds for the post section. The tubes are widely referred
to as "sono"
tubes although it will be understood that the present invention may be
practiced with any
suitable mold for the posts and is not limited to one particular kind thereof.
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The mold of the present invention may be formed of any suit;able material
having
the desired characteristics including, for example, various metallic or paper
or plastic or
rubber materials. In practice, the mold is preferably formed of a suitable
plastic material.
Many known plastic materials may be used and indeed, the mold of the present
invention
could be manufactured using recycled materials. It suffices to say that
suitable materials
are well known to those knowledgeable in the art and it is only important that
the mold
have the strength to withstand back filling and containment of the concrete
during the
setting period and that the top portion thereof be sufficiently flexible to
permit the
insertion of the post tube.
The manufacture of the mold may conveniently be accomplished by injection
molding. The main radial slits and secondary tab slits in the top wall ma.y
either be
formed as a result of the injection molding process or alternatively, they may
be cut within
the top wall after the mold is formed and to this end, appropriate indicia or
score lines
could be provided.
The radial slits may follow straight radial lines or be of a curved or spiral
nature.
The secondary slits forming alignment tabs may be cut or formed along the
sides
of the flexible flaps or cut or formed completely within the flexible flaps.
The tabs are
preferably arranged so that when the bottom of the inserted tube slides past
them, the tabs
will snap under the tube holing it aligned so as to be substantially
90° to thw base mold.
Molded protrusions on the underside (tube contact side) of the flexible flaps
may
also be used to align the tube 90° to the base.
The upper side of the flexible flaps may be scored or have tiny linear
protrusions
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that act as "tape gripping" lines.
The shape of the base mold is not critical and many different configurations
such
as circular, rectangular, square, polygonal, etc. may be employed.
The upper wall having the main slits formed therein can itself have various
configurations. Thus, the upper wall may comprise a generally horizontal flat
wall which
is normal to the vertical side wall or alternatively, it may taper upwards to
its center rising
above the sidewalls to have a conical or dome shaped configuration.
The mold may include means for securing it in place to avoid dislodging on
back
filling. To this end, there may be provided a series of holes in the mold
bottom rim to
allow it to be staked in place.
Having thus generally described the invention, reference will be made to the
accompany drawings illustrating an embodiment thereof, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure lA is a perspective view of a concrete post base mold according to one
embodiment of the present invention;
Figure 1B is a side elevational view thereof;
Figures 2A, 2B and 2C illustrate use of the concrete post base mold;
Figure 3A is a top plan view thereof;
Figure 3B is a perspective view of the top portion illustrating lifting of one
of the
flaps;
Figure 3C is a cross sectional view of the bottom of a tube inserted in the
top
portion of the concrete post base mold;
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Figure 4A is a top view of a slightly modified concrete post base mold;
Figure 4B is a side view thereof with one of the flaps being raised;
Figures SA and SB are perspective views of different embodiments of a concrete
post base mold;
Figures 6A and 6B are top views of alternative embodiments;
Figures ?A and 7B are top plan views of the top portion of a rr~old
illustrating
different arrangements for the slits; and
Figures 8A, 8B, 8C and 8D are perspective views of only the top portion
illustrating alternative embodiments thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in greater detail and by reference characters
thereto,
there is illustrated in Figure 1 a concrete post base mold which is generally
designated by
reference numeral 10.
Concrete post base mold 10 has a lower cylindrical side wall 12. Ribs 11 are
formed along the outer surface of door side wall 12. At its lower edge, side
wall 12
terminates in an outwardly extending flange which has a plurality of apertures
15 formed
therein.
At the upper peripheral edge of lower side wall 12 there is provided a first
upper
side wall 16 and a second upper side wall 17. Upper side walls 16 and 17 are
of a
frustroconical configuration and extend inwardly.
Extending inwardly from the upper marginal edge of second upper aide wall 17
is
a top wall 18 which, in the illustrated embodiment is of a generally planar
nature and
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extends in a horizontal direction.
Top wall 18 has an aperture 19 located centrally thereof from which extend a
plurality of radially extending slits. In this respect, there are provided a
plurality of main
slits 20 extending radially from aperture 19 and which main slits 20 aa-e
equally separated
from each other. The slits are all substantially equidistant.
It will be noted that main slits 20 each has at least one secondary side slit
24
extending therefrom.
A further set of slits generally designated by reference numeral 26 are
located
between radial slits 20.
The arrangement is such that a plurality of flaps 30 are formed by the
arrangement
of the main radial slits 20 and a plurality of tabs 40 are formed by the
arrangement of the
secondary side slits on flaps 30.
In the practice of the invention, and as shown in Figures 2A, 2B and 2C, a
conventional round tube form generally designated by reference numeral 32 is
moved
relative to concrete post base mold 10 such that flaps 30 are forced upwardly.
The tube is
moved upwardly through the flaps 30 until the bottom peripheral edge of tube
32 is
substantially at a level slightly above top wall 18 at the upper tip of tabs
40. A little
further movement will permit the tabs 40 to snap under the bottom periphc;ral
edge of tube
32. A slight downward force on tube 32 will then seat tube 32 onto tabs 40
aligning and
supporting tube 32 in a 90° attitude with respect to base mold 10. At
the same time, flaps
30 exert a pressure on the side wall of the tube to maintain it in position
and allow for a
large contact area between tube 32 and flaps 30 for affixing tube 32 to base
mold 10.
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If desired, tape 36 may be wrapped around the upstanding flaps 30 to provide
for
reinforcement of the arrangement. Other means such as screws, clamps or
adhesives
could likewise be used.
Subsequently, the concrete post base mold may be pinned in position utilizing
large spikes 45 through rim apertures 15 and back fill placed around the
arrangement.
Liquid concrete poured into the tube 32 will subsequently fill both the tube
32
and the base mold 10 thereby cast a one piece concrete post with footing.
In one alternative embodiment, in lieu of the slits, score lines may be
formed. The
end user would then cut or otherwise perform the slits along the score lines.
One could
also have indicia in lieu of the score lines.
There are many different possible embodiments and these are illustrated in the
Figures 4 through 8. Thus, in Figure 4B, protrusions 31 are provided on the
other side of
flaps 30 for engagement with tube 32. Protrusions 31 have an inverted '
riangular outline
to provide support for the bottom of tube 32.
As shown in Figure SA, side wall 17 may be eliminated leaving only side wall
16.
As shown in Figure 5B, the mold 10 may comprise a single whole shaped outline.
In Figure 6A, the whole flap area has an octagonal outline. Figures 6B, '7A
and 7B
illustrate other possibilities as do Figures 8A through 8D.
It will be understood that the above described embodiment is for purposes of
illustration only and that changes and modifications may be made thereto
without
departing from the spirit and scope of the invention.
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