Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROllND OF ~EIE INV~NTION
1. Field of the Invention
This invention relates in general to strut framing
systems and more particularly to a non-metallic, corrosion
resistant framing and mechanical support system for the
processes of the corrosive industries.
2. Discussion of the Prior Art
Strut framing systems have been widely used in the
U.S.A. as well as internationally for nearly fifty years.
However, the advent of high technology manufacturing
processes during the last decade has resulted in numerous
requirements for more state-of-the-art mechanical support
systems. Many attempts have been made by the historical
suppliers of strut systems to meet the demands of new
industries, but most attempts were based on the basic
industry out of which the strut systems have developed.
Various grades of stainless steel strut and fasteners have
been developed and are available at extremely high costs.
Plated and coated steel systems have been developed from
galvanizing epoxy to PVC coatings. More recently several
fiberglass strut channels have been introduced, however,
their struts are designed for metallic or metallic coated
fastener systems.
The strut systems of the present invention are all
non-metallic, corrosion resistant framing and mechanical
supports for the processes of the corrosive industries.
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The present invention combines two plastics design and
manufacturing methods to produce a mechanical support and
attachment system using all non-metallic components.
The structural strut is a specially designed
fiberglass pultruded shape incorporating the use of
composite structure design with a highly efficient
mechanical shape to produce the strongest and stiffest
support for the fastener system. The fasteners are
designed of high strength composite thermoplastics and are
injection molded in two halves. Their shape allows
attachment to the strut support without tools, and the
position locking connection provides a permanent but
adjustable locking support of the process piping or
ducting.
Prior to the filing of the present invention, a
preliminary patent search of the prior art was performed.
The following patents were found and are listed below:
U.S. Patent No. Inventor Issue Date
3,088,702 Orenick, et al 5/7/63
3,527,432 Lytle 9/8/70
3,721,750 Countryman 3/20/73
3,913,187 Okuda 10/21/74
4,061,299 Kurosaki 12/6/77
4,371,137 Anscher 2/1/~3
Perhaps the patent of most interest from this group
is U.S. Patent No. 3,527,432 issued to Lytle. Lytle shows
a longitudinal channel with retaining flange for holding
clamping plates which are curved to accommodate pipe or
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tubing. The plates are hooked to the flanges in the
channel. The ends adjacent to the curved portions of the
clamping plates are formed into parallel flanges with
registering holes to accommodlate a threaded fastener so
that the clamping plates can be tightened onto the pipe.
To facilitate insertion of the plates over the pipe and
into the channel, one of the clamping plates is provided
with two opposite hanging hooks on opposite edges, and the
other plate is provided wit]h one hanging hook. The
present invention differs in many respects from Lytle.
Th~ means of holding the bands of the present invention in
the flanges of the channel is different; the means of
fastening and holding the pipe or duct is different; also,
the bands used in the present invention are much different
than Lytle's plates both in structure and result.
Further, Lytle does not contemplate use of his support
system, in a corrosive application.
U.S. Patent No. 3,721,750 issued to Countryman shows
a plastic strapping fastener. It is much different than
the present invention in structure and function. ~he
other patents found in the search relate to the general
area of fastening systems, but in applicant's opinion,
either alone or in combination, do not disclose the key
elements of applicant~s invention as disclosed herein.
Another pertinent reference is U.S. Patent No.
8,226,069 to Clarke. Applicant would like to point out a
key and critical distinction between Clarke and their
invention. It lies in the top portion of the support
bands and more specifically in the contact between the
flanges on the hangar and the flanges on the support
element. Applicant is aware that merely changing Clarke's
hangars and support element to thermoplastic and/or
fiberglass would not result in patentability. If this
were done, Clarke's invention duplicated in plastic and/or
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fiberglass would fail due to tensilve load concentrations
at points in his anchors 26 and flanges 22. Clark~s
system relies on point and line contact of the anchors 26
and flanges 22, and suggests the use of ear 26b if flanges
24 are rounded, and ear 26s if flanges 24 are straight.
(See Clarke, col 3, lines 9-18). In metal, this point and
line contact would be acceptable and support the required
weight, since metal has sufficient tensile strength to
resist the tendency to bend the anchors 26 whether they
are shaped as in 26a or 26b, and whether flanges 22 are
rounded or straight. Stress concentration would occur in
ear shapes 26a at the point which the ear 26a meets the
medial portion 26c, and in ear shapes 26b similarly at the
points where the ear 26b changes direction, and at its
tip. In either case, flange 24 whether rounded or
straight would experience tensile stress due to bending
where the flange 24 meets the sides of support 10 Clarke's
anchors 26 and flanges 24 are typical of what is
conventionally available in the metal hangar art. This
system if duplicated in plastic and/or fiberglass would
fail when the conventionally required loads were placed
upon it. A more comprehensive interface between the
support element and hangar is needed, which is supplied by
applicants' invention.
SUMMARY OF T~E INVENTION
The present invention is a strut support system for
piping, tubing or ducting which includes first, a
structural support channel having a longitudinal slot.
The support channel also has longitudinal flanges along
the sides oiE the slot inwardly projecting toward the
centerline of the support channel. The present invention
also provides a pair of complemental composite
thermoplastic support bands having a bottom portion which
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forms a natural curvature for cradling a pipe when the
ends of the bands are engaged. The bands also have a top
portion with two support members having distal flanges
capable of engaging the longitudinal flanges of the slot
in the support channel when the top portion of the bands
is disposed within the longitudinal slot of the support
channel. The two support members of the top portion of
the support bands are res;ilient and permit easy
manipulation of the bands for insertion into the slot or
for removal from the slot. The bottom portion of the
bands has adjustable holding means for connecting and
locking the support bands around a pipe. This adjustable
holding means preferably includes a screw disposed in a
housing connected to the bottom portion of one support
band and a series of thread slots on the bottom portion of
the other support band. The screw and threads are capable
of engagement so that driving the screw adjusts the
diameter of the natural curvature of the bottom portion of
the support bands when the slotted end of the one support
band is disposed and threadably engaged with the screw in
the housing. A hex head is incorporated at either end of
the screws, allowing the support bands to be adjusted from
either side.
The present invention is also a pipe support
apparatus including a pair of flexible bands, each of the
bands having a resilient top portion with dogs on each
side thereof. The dogs have flat, parallel side portions
and undersides extending inwards at an acute angle with
the side portions and towards said top portion. A
connector is provided on a bottom end of each band for
connecting the pair of bands together. The dogs may have
rounded edges between the side portions and the undersides
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and may have concave fillets along the undersides. The
dogs may also have interior cavities. The pipe support
apparatus may have members extending between the dogs of
each top portion and the bands may be inwardly concave.
It was an object of the present invention, therefore,
to provide a non-metallic corrosion resistant framing and
mechanical support system for pipes or ducts.
It is another object of the present invention to
provide a highly efficient fa~tening system which allows
attachment to the strut support without the use of tools.
It is a further object of the present invention to
provide a strut support svstem for use in corrosive
application which is relatively inexpensive.
These and other objects and advantages of the present
invention will become more apparent from the following
detailed description when taken in conjunction with the
attached drawings.
Brief Description of the Drawings
Figure 1 is assembly application in accordance with the
present invention.
Figure 2 is an elevation view of a support band of the
present invention.
Figure 3 is a sectional view of the support band and
longitudinal channel partially in cross section in
accordance with the present invention.
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Figure 4 i5 an elevation view in cross section of the
support band showing the adjusting means.
Detailed Description of the Preferred Embodiment
Referring to the Figure 1, a pair of fiberglass
channels 2 are shown, Channels 2 have longitudinal slots
generally referred to as 4 and a pair of longitudinal
flanges 6a and 6b. Flanges 6a and 6b project inwardly
toward the center line of channel 2. Channel 2 is
considered to be a structural support element for the
entire strut system. Referring to Figure 2, composite
thermoplastic pipe supporting band generally designated as
7 is shown. Pipe supporting band 7 us comprised of a pair
of supporting bands 8a and 8b used in the strut support
system of the present invention. The complemental nature
of this pair of support bands will be described
subsequently.
Each pair of support bands 8a and 8b has a top
portion, designated as lOa and lOb with two support
members 12a and 12b. The support members 12a and 12b of
support bands 8a and 8b have a-pair of lateral dogs 14a
and 14b extending therefrom. The dogs 14a and 14b are
used to engage the flanges 6a and 6b of the channel 2 when
the strut system is in operation as shown best in Figure
3. The top portions of each support band 8a and 8b has a
web 15 with a hole 17. The support bands 8a and 8b also
have bottom portions generally designated as 16a and 16b.
The bottom portion 16a and 16b of the support bands 8a and
8b have a natural complemental curvature to allow cradling
of a pipe (not shown) when the ends of support band 8 are
engaged. The bottom portion 16a of the support band 8a
has a housing 13 with a screw 20 disposed therein. The
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bottom portion 16b~of the other support band 8b has a
series of thread slots designated as 22 (see Figure 4)
capable of threadable engagement with the threads 24 of
screw 20. The housing 13 is adapted to receive the slots
22 of support band 8b when locking and tightening of the
support system is desired during operation. A hex 26 is
molded on the end of s~rew 20 to allow adjustment of the
support bands from the end opposite the head of screw 20.
In operation, the longitudinal channel 2 is
appropriately hung in place, being supported to a ceiling
(not shown) or the like by suitable conventional means.
Each of the support bands 8a and 8b are manipulated by
hand so that dogs 14a and 14b of top portion 10 of the
support bands 8a and 8b are made to engage with flanges 6a
and 6b of channel 2. A pipe to be supported is placed
between the pair of bands 8a and 8b so that the curvature
of the band 8a containing the bolt 20 and housing 18 is
directed toward the curvature of band 8b containing the
slots 22. The bottom portion of the band 8b is then
pushed through the housing 18 contained on the other band
8a until the slots 2 engage threads 24. The pair of bands
8a and 8b can now be finally adjusted by driving the screw
20 with a screwdriver (not shown) or the like until the
desired tightness around the pipe is achieved.
Alternatively, hex 26 can be driven to achieve the desired
adjustment. The hex 26 gives the support system added
flexibility with respect to access of an operator in
adjusting the system. The strut system can be used with
any size pipe or ducting by increasing or decreasing the
size of the channel 2 and the support bands 8a and 8b.
Referring to Figure 2 and 3, the engagement of dogs
14a and 14b, and the channel 2, as shown in that figure
can be described. From Figure 2 it should be noted that
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dogs 14a and 14b have side portions 28a and 28b, flat
undersides 30a and 30b, rounded fillets 31a and 31b, and
rounded bottom edges 32a and 32b. As seen in Figure 3,
side portions 28a and 28b have convex upper portions 41
and 42 and flat, parallel lower portions 44 and 46 which
are vertical in use. The lower side portions 44 and 46
extend at an acute angle with undersides 30a and 30b.
From Figure 3, longitudinal flanges 6a and 6b have rounded
edges 34a and 34b. The interior surfaces 36a and 36b of
flanges 6a and 6b have rounded fillets 38a and 38b where
the flanges 6a and 6b meet the sides 40a and 40b of
channel 2. When dogs 14a and 14b engage flanges 6a and
6b, substantially full and interlocking contact occurs ~as
shown in Figure 3) between the side portions 28a and 28b
of the dogs 14a and 14b, and the sides 40a and 40b of the
channel 2. This contact or engagement also includes the
undersides 30a and 30b of dogs 14a and 14b, including
rounded edges 32a and 32b and fillets 31a and 31b and the
interior surfaces 36a and 36b of flanges 6a and 6b
including fillets 38a and 38b, and rounded edges 34a and
34b. The radii of rounded edges 32a, and 32b and 34a, 34b
will depend on the size of pipe to be supported. Interior
cavities 48 and 50 in the dogs 14a and 14b ease
deformation of the dogs for insertion of the top portions
of the pair of bands into the channel.
As an alternative to web 15, a cross element (not
shown) could be used. This element would extend between
the dogs 14a and 14b. In operation in very tight spaces,
web 15 or the cross element can be severed allowing easier
manipulation of the dogs 14a and 14h into engagement with
flanges 6a and 6b.
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The invention may be embodied in other forms without
departing from the spirit or essential charact~ristics
thereof. The present embodiments are therefore to be
considered in all respects as illustrative and not
restrictive, the scope of the invention being indicated by
the appended claims rather than the foregoing description,
and all changes which come within the meaning and range
equivalency of claims are therefore intended to be
embraced therein.
