Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Field of the Invention
This invention relates to eavestroughing systems
in particular the combination of a roll-formed sheet metal
eavestrough with plastic injection molded fittings.
Background of the Invention
It is generally accepted in the eavestroughing trade
that metal fittings are used with metal eavestroughing and
plastic fittings are used with plastic eavestroughing.
Several approaches have been taken in the past to simplify
the installation of metal eavestroughing on homes, such as
in the use of cast brackets which are secured to the eaves
to retain the metal trough in position. However, casting
of brackets is relatively expensive. The standard spike
and furrel is, therefore, commonly used in attaching metal
eavestrough to an eave. In the line of plastic eavestroughing
several advances have been made in providing fittings to
join plastic trough and secure it to an eave. Such plastic
troughing and fittings may be of the type disclosed in
United States patent 3,355,895. There are several drawbacks,
however, in using plastic eavestroughing, in that it readily
cracks in the colder climates such as when a ladder is
placed agalnst the troughing. The thermalexpansion of
plastic troughing is substantially greater than metal and
is in the range of at least ten times greater; therefore,
special fittingshave to be devised to accommodate this
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substantial variation in the length of the trough during
seasonal changes in climate. The complex structures that
are, therefore, devised may be of the type shown in the above-
referred ~o United States patent to accommodate this thermal
expansion in plastic fittings. The further problem
encountered with respect to plastic troughing is that it is
usually extruded, thereby requiring year-round production of
the trough in order to accumulate sufficient inventory to
meet the demands of spring, summer and fall construction
trades. With the best of extruders used, it is appreciated
in~the art that only about 750 feet of trough may be extruded
in an hour. Therefore, to avoid year-round production, more
extruders may be purchased; however, this proves to be
extremely costly, since one extruder may be in the range of
$150,000 to $200,000 capital investment. As a result, the
manufacture of plastic troughing requires a very high
capital investment which makes it very difficult to maintain
profitable margins in the industry with the wide fluctuation
in the cost of plastic resin.
A further drawback that has been encountered in the
use of plastic eavestroughing systems is that the trough
cannot be formed of plastic which can maintain a dark colour
over extended periods of time. Most plastic troughing is,
therefore, of the lighter pastel colours which limits the
market to which the troughing may be directed. It is now
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desired by the consumer that darker eavestroughing be
provided to match various darker roof colours. With the
darker colours of plastic eavestroughing, the problem encoun-
tered is that the ultra-violet radiation tends to bleach the
trough over period of time, so that its life is limited.
I have discovered that the use of a roll-formed sheet
metal eavestrough with plastic injection molded fittings,
therefore, provides substantial advantages. In using the
metal eavestrough with plastic fittings, the thermal expansion/
contraction of the metal is substantially less than in plastic,
as already mentioned. The use of metal eavestroughing is
an all-weather type of installation, in that during the winter
time, no concern need be given to cracking induced by blows,
such as placing a ladder against the house or due to wide
variations in expansion and contraction of the metal. The
steel may be zinc coated, primed and covered with a topcoat
of paint to give any desired colour where the life expectancy
of such coats is roughly twenty years. The steel is easier
to install in that it has a smoother sidewall portion and
due to its particular construction is more flexible to
permit snapping of the troughing into the fittings. The
paint coat on the steel readily resists ultra-violet degre-
dation to thereby meet the demands of the marketplace with
respect to darker coloured material. As mentioned, one of
the problems with former metal systems is that it was
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difficult to form the fittings out of metal; however, in
adapting the use of plastic fittings, they are readily
injection molded. In roll-forming the eavestroughing, it
is appreciated that such units require substantially less
capital investment and roll-forming speeds of approximately
9,000 feet per hour can be achieved which is roughly 12
times the rate of production with respect to extruding
plastic eavestroughing. As a result, the fluctuating
demands of the marketplace with respect to eavestroughing
can be met on a more short-term basis resulting in substan-
tially less carry of inventory throughout the year.
It is, therefore, an object of the invention to
provide an eavestroughing system which is far superior to
known metal eavestroughing systems and known plastic eaves-
troughing systems.
It is a feature of the invention to accomplish such
object in the combined use of a roll-formed sheet metal
eavestrough with plastic injection molded fittings or
supports therefor.
The above-identifiedadvantages flow from this feature
of the invention.
Summary of the Invention
The eavestroughing system, according to this invention,
comprises in combination a roll-formed sheet metal eaves-
troughing and plastic injection molded fitting supports
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therefor. The eavestrough has compactly overturned,
longitudinally extending edge portions of a thickness subs-
tantially greater than the thickness of the metal. The
fitting is formed of semi-rigid plastic and has two spaced-
apart clip portions to receive the trough edge portions.
The fitting has a body portion with an internal surface
approximating the external shape of the trough to encompass
same when the trough is clipped into and supported by the
plastic support.
The roll-formed sheet metal eavestrough, having the
overturned upper edges, provides an unexpected resiliency
which readily permits snapping of the metal trough into the
plastic support and recovers to snug up the relationship
of the trough relative to the fitting to provide a secure
supporting and affixing of the trough to the eaves.
Description of the Drawings
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Preferred embodiments of the invention are as shown
in the drawings wherein:
Figure 1 is an exploded view of the roll-formed
sheet metal eavestrough and plastic fittings therefor;
Figure 2 is an exploded view of the roll-formed metal
eavestrough with other fittings therefor;
Figure 3 is an exploded view of a further plastic
fitting for the metal eavestrough;
Figure 4 shows the manner in which the metal eaves-
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trough is inserted in the plastic fitting of Figure 3;
Figure 5, which appears on the sheet with Figure 1,
is a section through a preferred shape for the roll-formed
metal eavestrough;
Figure 6 shows the roll-formed metal eavestrough of
Figure 5 about to be inserted in a plastic fitting; and
Figure 7 shows the assembled combination of Figure
6.
Detailed Description of the Preferred Embodiments of the
Invention
Figure 1 shows the two roll-formed sheet metal
eavestrough sections 10 and 12 about to be clipped into a
plastic injection molded joining member 14. To complement
the system, a mitre joining member 16 is shown for traversing
the corner of a house where the ends of eavestrough section
12 and section 18 are inserted into the clip portions of
mitre 16.
Figure 2 shows further injection molded plastic
fittings for the eavestroughing system where an eavestrough
section 20 is held by support 22. The end 24 of eavestrough
section 20 and end 26 of eavestrough section 28 are clipped
to a further plastic fitting 30 which includes a downspout
32.
A further type of plastic fitting for use with the
eavestrough is shown in Figure 3, where the end 34 of
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eavestrough section 36 is inserted into a blind end cap 38.
The manner in which the eavestrough section 36 is inserted
into the blind end cap 38 is shown in Figure 4.
A preferred embodiment for the cross-sectional shape
of the roll-formed eavestrough is shown in Figure 5 where
the eavestrough section 40 has a base portion 42 to each
side of which is a generally upwardly extending sidewall
44. The sidewall is compound of an outwardly, upwardly
extending portion 46 and an essentially vertically extending
portion 48 which merges into overturned portion 50. The
overturned portion 50 is the upper extremity of the vertical
portion 48, folded twice onto itself such that the raw
edge 52 is tucked up under the overturned portion 50.
Gaps 54 are formed in the overturned portion which are of
minimal dimension; however, are such that the thickness of
the overturned portion 50 may be approximately four to
five times the thickness of the metal in the trough section
40.
The roll-formed trough may be of various thicknesses
preferably of 30 or 28 gauge. As a result, the overturned
portion 50, when turned over in the manner shown, has a
thickness of approximately 70 thousands of an inch due to
the gaps provided.
The plastic injection molded fittings may be formed
from various well-known, readily available plastics, such as
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polyvinylchloride which withstands the severity of winters
and hot summers and is not readily cracked in the colder
climates. Further, colours may be admixed with the poly-
vinylchloride to give various colours which contrast with
or match the exterior colour of the troughing sections.
The polyvinylchloride is semi-rigid to permit a degree of
flexibility in the support or fitting portions to permit
clipping or snapping of the trough into the support members.
The fittings are injection molded to thereby accomplish the
various configurations needed for the fittings as shown in
Figures 1 through 4 of the drawings, such as the butt joiner
14, the mitre 16, the downspout 30 and the end cap 38.
The sheet metal may be prepainted prior to roll-forming
the troughing; for example, the strips which are subsequently
rolled to form the trough may be formed by slitting a
coil of prepainted sheet. Therefore, there is the advantage
of tucking the raw edge 52 up underneath the overturned
portion 50 to protect it from the elements. The troughing
may be painted in any desired colour where preferably it
is zinc coated, primed and then followed with a topcoat
which may be baked to substantially prolong the trough's
finish life. It is desired to provide a trough finish which
will last approximately twenty years.
Turning to Figure 6, the butt joiner fitting 14 is
shown. The joiner 14 comprises a body portion generally
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designated 56, having a base portion 58 and generally
upwardly extending sidewalls 60 of shape approximating the
exterior shape of the eavestroughing section 40. Affixed
to the inside surface of the body portion 56 is a compressible
or resilient sealing liner 62 which preferably is secured to
the body portion by the use of an adhesive. The dimensioning
of the internal surface 57 is such that, with the liner in
position, the troughing 40 can be snapped into the joiner 14.
The upwardly extending leg portions 60 and 61 terminate in
the clip portions 64 and 66.
The leg portion 61 has at its upper end an aperture
68 which facilitates or permits fastening of the joiner 14
to the eaves or facia board. Molded with the body portion
is a downwardly depending flange or face shown in dot as
70 to secure and prevent twisting of the joiner when affixed
to the facia board. It is understood that the other fittings
include such flange portions with apertures to permit
affixing to the eave.
The liner thickness is selected such that it may be
compressed a certain degree upon forcing an end of the
trough section 40 into the joiner 14. It has been found
that, with this design for the trough, it can be flexed about
its compound sidewalls to cause in base portion 42 an
innerward bowing to facilitate positioning of the overturned
portions 52 beneath the downwardly depending lugs 65 of the
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clips. This flexing in the trough is more readily
accomplished than with the prior plastic extruded sections.
The reason for this is that a very thin wall may be used
for the trough and then the needed thickened portion at the
top provided by the overturned section. On the other hand,
with a plastic extrusion, a much thicker wall is required
to impart the desired structural characteristics needed,
thereby detracting from the flexibility of the plastic
extrusions. As a result, substantial forces are needed to
place the plastic troughing section into the joiners and
other injection molded fittings. As can be appreciated,
in cold weather the plastic is much stiffer and in some
instances, it is practically impossible to accomplish an
installation in the winter time. Whereas with the metal
plastic combination for the eavestroughing system of this
invention, the metal is, of course, readily flexed in the
winter time to facilitate installation.
The preferred manner of inserting the trough into
the joiner 14 is to place its rear overturned edge 50a
beneath the clip 66 and then with a downward component
of force in the direction of arrows 72 and an inward
movement of force in the direction of arrow 74, the trough
is pushed beneath the other clip 64 by depressing the foam
or compressible liner 62. The bowing of the base portion
42 is shown in dot 42a in Figure 7. This permits the
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overturned portions 50 to be inserted beneath the clips
64 and 66. When the overturned portion 50 is beneath the
clips, the base portion 42 attempts to resume its original
planar position to the extent shown in Figure 7, thereby
pushing its base down against the compressible liner 62 so
as to achieve a substantially contiguous contact of liner
with the exterior of the troughing around its base and
upwardly extending sidewalls to achieve a seal. This is
necessary, as shown in Figure 1, where the joiner 14 is
used to butt join trough sections 10 and 12 such that a
sealing portion of the compressible liner 62 emcompasses
or contacts at least the base portions 42 of each trough
end portion to form a proper joint, so that there is no
leakage in this area.
The various plastic fittings which entail joining
one section of trough to the other, incorporates a
compressible liner such as 62 in joiner 14. For example,
in the mitre 16, the clip portions generally designated
as 76 include therebeneath compressible liner 78, similarly
clip 80 has compressible liner 82. Also, the downspout
30 has compressible liner 84 and end cap 38 has compressible
liner 86. All of these are designed to function in the
manner shown in Figures 6 and 7 to provide a waterproof
joining of the end of the trough section to the joiner.
It can be appreciated that, in using a roll-formed
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eavestrough section, it is possible to use portable
roll formers so that on-site forming of the trough section
may be accomplished. As a result, sufficiently large
strips may be carried to the site to thereby form a trough
section which would extend the entire length of the house
or building to which it is to be affixed. Roll-forming
of the trough provides a reasonably precise control on the
profile so that a superior and more consistent joining may
be achieved with the injection molded plastic fittings.
The turned-over edge of the eavestrough provides a
strong section such that ladders and the like may be
leaned against the trough and not deform the trough side-
walls. Further, such overturned edge in having the gaps
formed therein prevents kinking of the trough more readily
than would be the case with other types of metal troughing.
Other portions of the eavestrough assembly may be
roll-formed, such as the down pipe which is connected to
the spout 32 of fitting 30. Again, in roll-forming this
box section, one achieves the high rates of production and
durability as compared to the plastic extruded sections.
It is apparent that this eavestroughing system is
readily installed by the householder, that is a do-it-
yourself installation. However, new house construction
can benefit from this type of eavestrough system because
on most new homes plain galvenized steel troughing is
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installed. A plain galvenized steel troughing, as shown in
Figure 5, requires substantially less metal than the
prior types of troughing. This system requires no soldering,
therefore, avoidspotential injuries to the installer and
in avoiding the soldering step provides for faster instal-
lation. No compounding is required in the joints
that contraction/expansion of troughing does not cause
leaks, therefore on new homes installation of this system
frees the installer from callback problems, providing
the troughing is installed properly with the plastic fittings.
It can, therefore, be realized that this combi-
nation of roll-formed sheet metal eavestrough and plastic
injection molded support fittings therefor~ to secure the
eavestrough to the building walls or eaves, provides a
system which gives the unexpected improved joining
capabilities and water tightness, together with all of
the advantages which flow from the roll-forming of the
troughing and the injection molding of the plastic parts.
Although various embodiments of the invention have
been described herein in detail, it will be understood
by those skilled in the art, that variations may be made
thereto without departing from the spirit of the invention
or the scope of the appended claims.
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