U.S. patent application number 09/911363 was filed with the patent office on 2002-02-21 for grommet for use with sheet metal structural member.
This patent application is currently assigned to Rotary Press Systems Inc.. Invention is credited to Bodnar, Ernest R., Bogart, Ronald J., Lamers, John P..
Application Number | 20020020139 09/911363 |
Document ID | / |
Family ID | 23602267 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020139 |
Kind Code |
A1 |
Bodnar, Ernest R. ; et
al. |
February 21, 2002 |
Grommet for use with sheet metal structural member
Abstract
A Sheet Metal Structural Member has flanged openings formed
therein to permit the passage of services therethrough. A grommet
is provided that has a shape that corresponds generally to the plan
form shape of the openings. The grommet has a peripheal wall and
seating elements arranged about the peripheral wall to mate with
the flanges that are located about the flanged opening. The grommet
snaps into place and resists movement once installed. The grommet
has radiused edges to discourage damage to service conduits or
wiring carried therethrough.
Inventors: |
Bodnar, Ernest R.; (Toronto,
CA) ; Bogart, Ronald J.; (Aurora, CA) ;
Lamers, John P.; (Ingersoll, CA) |
Correspondence
Address: |
BLAKE, CASSELS & GRAYDON LLP
BOX 25, COMMERCE COURT WEST
199 BAY STREET, SUITE 2800
TORONTO
ON
M5L 1A9
CA
|
Assignee: |
Rotary Press Systems Inc.
|
Family ID: |
23602267 |
Appl. No.: |
09/911363 |
Filed: |
July 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09911363 |
Jul 23, 2001 |
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09405098 |
Sep 27, 1999 |
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6263634 |
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Current U.S.
Class: |
52/831 |
Current CPC
Class: |
E04C 2003/0421 20130101;
E04C 2003/0452 20130101; E04C 2003/043 20130101; E04C 2003/0413
20130101; E04C 3/09 20130101; E04C 2003/0434 20130101; E04C
2003/0473 20130101 |
Class at
Publication: |
52/731.9 |
International
Class: |
E04C 003/30 |
Claims
We claim:
1. The combination of at least one beam-like longitudinally
extending structural member, and at least one grommet for use in
co-operation therewith, wherein: said structural member has a web,
said web having a longitudinal edge, and a longitudinally extending
main flange running along said edge; said web has at least one
opening therein, and flangework formed adjacent to said opening;
said grommet has a peripheral wall having an internal face defining
a passageway, said wall having a leading portion that can be
introduced into said opening in said web, and a trailing portion
having at least one seating element extending outwardly of said
wall to prevent passage of said trailing portion fully through said
opening; said grommet has at least one biased member having an
abutment element biased to an opposed position relative to said
seating element said biased member being moveable to a deflected
position during introduction of said trailing portion into said
opening; and said grommet is moveable to engage said seating
element against one of (a) said flangework and (b) said web, and,
when so engaged said abutment element is moveable to said opposed
position under the influence of said biased member, and, in said
opposed position said abutment element discourages removal of said
grommet from said opening.
2. The combination of claim 1 wherein said opening has a periphery
defined in said web, said peripheral wall has at least one side
wall portion extending between a pair of sidewall ends, one of said
seating elements and one of said abutment elements are located at
each end thereof, and, in an installed position of said grommet
relative to said structural member said side wall portion has a
span free of contact with the periphery of said opening.
3. The combination of claim 1 wherein: said structural member has a
pair of opposed main flanges extending along opposite edges of said
web; a plurality of said openings are formed in said web, each of
said openings having a base side portion extending parallel to one
of said main flanges and a pair of side portions extending from
said base side to meet at a smoothly radiused apex opposite said
base side portion, said openings being arranged along said web in
alternating side-by-side fashion with alternating diagonally
extending struts formed in said web between pair of adjacent
openings; and said flangework extends along said struts and said
base side portions.
4. The combination of claim 1 wherein: said opening has a base side
portion extending parallel to said main flange and a pair of side
portions extending from said base side to meet at a smoothly
radiused apex opposite said base side portion, said side portions
and said base portion of said opening meet at smoothly radiused
base corners; and said grommet engages said flangework at said base
corners and at said apex.
5. The combination of claim 4 wherein: said grommet has a base
portion locatable adjacent said base portion of said opening, and a
pair of side portions locatable adjacent to said side portions of
said opening; and said base portion and said side portions of said
grommet meet at respective attachment fittings that seat in said
corners and said apex of said opening.
6. The combination of claim 4 wherein said flangework forms a
continuous peripheral lip around said opening.
7. The combination of claim 4 wherein said apex has a larger radius
of curvature than either of said base corners.
8. The combination of claim 5 wherein said web lies in a web plane,
portions of said flangework extend about said corners and said apex
of said openings; and said portions of said flangework have
respective distal edges formed out of the plane of said web at a
tapered angle whereby the entrance of said opening at the plane of
the web is wider than the exit of said opening adjacent said distal
edges, said leading portion being moveable along an insertion
direction running from said entrance toward said exit of said
opening.
9. The combination of claim 8 wherein said attachment fittings have
column members shaped to conform to the taper of said flangework at
said corners and at said apex.
10. The combination of claim 8 wherein: each of said attachment
fittings includes one of said abutments, one of said seating
elements, has a pair of said column members and an overspanning
member attached thereto adjacent the leading portion of said
grommet; each said attachment fitting has an arm depending from
said overspanning member, said arm having said abutment formed
thereon, and having an outwardly facing cam member engageable with
the taper of said flangework to cause said abutment to deflect; and
in said opposed position said abutment engages said distal edge of
said flangework.
11. The combination of claim 10 wherein each of said seating
elements has an outwardly extending resilient wing, said resilient
wing waving an interface member for engaging said web, and said
resilient member is operable to exert a rearward force on said
abutment when said grommet is engaged with said structural
element.
12. The combination of claim 1 wherein said grommet includes at
least one internal partition to define a plurality of passageways
therethrough.
13. A kit comprising at least one sheet metal structural member and
at least one grommet for use in co-operation therewith, wherein:
said sheet metal structural member has a pair of opposed, spaced
apart, parallel main flanges and a web extending therebetween, said
web having an outer face lying predominantly in a web plane and an
inner face lying to one side thereof, said main flanges extending
perpendicularly to said web plane and away from said outer face, to
give said sheet metal structural member a C-shaped appearance when
viewed from one end thereof, said web has a plurality of triangular
openings formed therein in an alternating arrangement, and a
plurality of alternating, flanged diagonal struts formed between
adjacent pairs of said openings, said openings having smoothly
radiused corners; said web has lip flangework formed therein
adjacent each said opening, said lip flangework standing proud of
said inside face of said web; said grommet has a peripheral wall
having an internal face defining a passageway, said wall having a
leading portion that can be introduced into one of said openings in
said web, and a trailing portion having at least one seating
element extending outwardly of said wall to prevent passage of said
trailing portion fully through said one opening; said grommet has
at least one biased member having an abutment surface biased to an
opposed position relative to said seating element, said biased
element being moveable to a deflected position during introduction
of said trailing portion into said one opening; and said abutment
element and said seating element defining a capture depth at least
great enough to capture said lip flangework and said outer face
therebetween when said seating element engages said sheet metal
structural member and said abutment surface moves to said opposed
position.
14. The kit of claim 13 wherein said lip flangework is continuous
flange extending about said triangular opening.
15. The kit of claim 13 wherein: said smoothly radiused corners of
adjacent openings define root portions of said struts adjacent said
corners; and said grommet has three seating elements and three
biased members, spaced about said peripheral wall in positions to
engage said sheet metal structural member adjacent said smoothly
radiused corners of said opening.
16. The kit of claim 13 wherein: portions of said flangework extend
about the corners and apex of said opening; said portions of said
flangework have respective distal edges formed out of said web
plane at a tapered angle such that toe entrance of said opening at
the plane of the web is wider than the exit of said opening
adjacent said distal edges, said leading portion being moveable
along an insertion direction running from said entrance toward said
exit of said opening; and said grommet has attachment fittings
locatable in said corners and said apex of said opening, and said
attachment fittings have column members shaped to conform to the
taper of said flangework at said corners and at said apex.
17. The kit of claim 13 wherein: portions of said flangework extend
about said corners and said apex of said opening; said portions of
said flangework have respective distal edges formed out of the web
plane at a tapered angle such that the entrance of said opening at
the web plane is wider than the exit of said opening adjacent said
distal edges, said grommet includes attachment fittings engageable
with said structural member adjacent said corners and apex of said
opening; each of said attachment fittings includes one of said
abutments, one of said seating elements, has a pair of said column
members and an overspanning member attached thereto adjacent the
leading portion of said grommet; each said attachment fitting has
an arm depending from said overspanning member, said arm having
said abutment formed thereon, and having an outwardly facing cam
member engageable with the taper of said flangework to cause said
abutment to deflect; and in said opposed position said abutment
engages said distal edge of said flangework.
18. The kit of claim 13 wherein each of said seating elements has
an outwardly extending resilient wing, said resilient wing waving
an interface member for engaging said web, and said resilient
member is operable to exert a rearward force on said abutment when
said grommet is engaged with said structural element.
19. The kit of claim 13 wherein; peripheral wall has corner
portions and straight side portions extending between said corner
portions; and said corner portions have corner wall facings
standing outwardly of said walls such that a straight edge laid
across said corner wall facings stands clear of the side wall lying
therebetween.
20. The kit of claim 13 wherein said grommet has at least one
partition wall lying inwardly of said peripheral wall to define at
least one other passageway through said grommet.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/405,098 filed Sep. 27, 1999.
FIELD OF INVENTION
[0002] This invention relates to the field of grommets, and, in
particular to a grommet that is mountable in a formed aperture in a
web section of a formed metal structural member, and a combination
of the grommet with a structural member.
[0003] 2. Background Art
[0004] It is possible to manufacture formed sheet metal posts and
beams that can be used as an alternative building material to
wooden studs, rafters, stringers, and beams that have been commonly
used. It is advantageous to produce such structural members in a
manner that may tend to enhance their strength-to-weight ratio,
while also tending to reduce the heat loss that may occur across
the section of the structural member. As shown in U.S. Pat. No.
5,527,625 of Bodnar, issued Jun. 18, 1996, one way to address these
objective is to provide a roll-formed metal member hiving a web and
a pair of opposed flanges, in a generally C-shaped channel-like
section, and then to blank the web to leave alternating diagonal
struts with formed flanges such that the remaining web has a
somewhat truss-like appearance when viewed perpendicular to the
web.
[0005] The manner in which the openings are formed through the web
of the structural member, and the manner of forming the flanges, is
such that it is advantageous to provide a relatively smoothly
radiused transition into the web adjacent to the opposed
out-of-plane flanges.
[0006] In a conventional wooden stud or rafter, services, such as
electrical power wiring, plumbing, telephone or other
communications wiring, or built-in vacuum lines, may tend to be
carried though holes bored in the mid-section of the stud or
rafter. Wooden studs tend not to be good electrical conductor, and
may tend to dampen vibration, in most cases services can be mounted
directly in contact with the wood. It is not desirable to have
holes bored in sheet metal structural members on the job site,
since this is a process over which thee is very little quality
control, and hence significant opportunity to impair the structural
performance of the section. Furthermore, in a formed sheet metal
structural member that has had openings blanked in it, and flanged
struts formed in it adjacent to the openings, there maybe little or
no need to drill additional opening.
[0007] However, while it would be possible to run services directly
through the openings formed in the web, it may also be undesirable.
The formed metal member may have sharp edges, and it may tend not
to be practical to have all of those edges smoothed down. It may
not be desirable to have electrical wiring chafe against a sharp
metal edge over a period of time, under vibration loads. Similarly,
it may not be desirable to run water pipes, whether hot or cold, in
direct contact with the metal section. For these reasons an
intermediate isolating or cushioning member may be desired.
[0008] A cushioning member, or grommet, for use with the formed
sheet metal structural member has a number of desirable properties.
In a construction project such a grommet may be required at one or
more formed openings in very stud in a wall, and in one or more
walls in every room in a house or other building The person
installing the grommets may do so many times per day. An
installation that requires complicated tools or procedures is
unlikely to be one that will be undertaken with a high level of
diligence on a repetitive basis, particularly as the installer
grows weary or disinterested.
[0009] While it is advantageous for the grommet to be easily
installed, it is also desirable that the grommet not tend to be too
easily removed. The grommet may be required to stay in service for
many years. A loose fit may not be desirable, particularly if
vibration is a concern, as it may be in a water pipe fitting, or a
fitting subject to repetitive loading over a relatively long period
of time
[0010] In the type of sheet metal structural member in question,
the depth of the strut flanges may tend to be greatest at mid so,
and may tend to be reduced in the radiused corners where the struts
meld into the margin of the web that adjoins the flanges. The
dimensional control over the distance from strut to strut may tend
to be poorest at mid strut, and relatively greater in the corners
of the opening adjacent to the web margin. The web margin may also
tend to be a region of lesser potential for deflection due to
vibration than the mid strut region. It is advantageous to have an
insulating grommet that is capable of engaging the toot corners of
the formed opening.
[0011] It is advantageous to produce a family of grommets of the
same, or similar, base width dimension, each having a different
attitude for use with a different width of strudel member, rather
than using the same longitudinal base to cross-web altitude aspect
ratio. The use of the same aspect ratio grommet at different sizes
would correspond to structural members having greater pitch centers
between adjacent openings When using a rotary press with
interchangeable dies, the pitch center distance is determined by
the fixed radius of the successive pivot axes of the rotary dies
carriers and seats. Since it is difficult to change this dimension
it is advantageous to change the height of the openings transverse
to the web, while maintaining the pitch between openings at a
constant distance.
SUMMARY OF THE INVENTION
[0012] In one aspect of the present invention there is a grommet,
for use with a structural member having a web and an opening
defined in the web. The opening has flangework adjacent the opening
The grommet is insertable into the opening when moved forwardly
along an insertion direction. The grommet comprises a peripheral
wall defining a passageway therewithin. The wall has a leading
portion for insertion into the opening and a trailing portion; and
at least two seating elements extending outwardly from the trailing
portion of the wall to prevent the trailing portion from passing
through the opening. The grommet has at least two abutments
connected to the peripheral wall. The abutments are moveable to a
deflected position to permit entry of the leading portion into the
opening, and the abutments are biased outwardly relative to the
peripheral wall to an opposed position relative to the seating
elements. The seating elements are spaced from the abutments in the
insertion direction to permit the web flangework to be captured
therebetween. The abutments and the seating elements are spaced
about the peripheral wall to inhibit forward and rearward motion of
the grommet relative to the structural member in the insertion
direction when the abutments are in the opposed position.
[0013] In an additional feature of that aspect of the invention, at
least one of the seating elements is resilient, The grommet is
moveable to an inserted position relative to the structural member.
In the inserted position the abutments are able to move to the,
opposed position and the resilient seating element is pre-loaded.
The pre-loaded resilient seating element is operable to exert a
rearward force on the abutments.
[0014] In another additional feature of that aspect of the
invention, at least one of the seating elements is resilient and
has a distal tip region that is cantilevered outwardly from the
peripheral wall. The distal tip region has a forwardly protruding
formation thereon. The grommet is moveable to an inserted position
relative to the structural member. In the inserted position the
abutments are able to move to the opposed position and the
forwardly protruding formation is engageable with the structural
member to cause the distal tip region to deflect rearwardly
relative to the peripheral wall, thereby applying a pre-load to the
resilient seating element. The pre-loaded resilient seating element
is operable to exert a rearward force on the abutments, thereby
squeezing the structural member between the abutments and the
seating elements.
[0015] In a further additional feature of that aspect of the
invention, the seating elements include flanges cantilevered out
from the peripheral wall, The flanges have a rearward face and a
distal edge, and, when installed on the structural member, the
rearward face of the cantilevered flange adjacent to the distal
edge stands rearwardly relative to the remainder of the cantileverd
flange.
[0016] In a still further additional feature of that aspect of the
invention, the grommet has a divider extending internally of the
peripheral wall to define a second passage therewithin.
[0017] In yet a further additional feature of that aspect of the
invention, the divider is placed to lie outside the largest
inscribed circle that can be constructed within the peripheral
wall.
[0018] In yet still a further additional feature of that aspect of
the invention, the trailing portion of the peripheral wall has an
outwardly extending flange mounted thereon. The flange is
substantially planar.
[0019] In another aspect of the invention, there is a grommet, for
use with a structural member having a web and an opening defined in
the web. The opening has at least three smoothly radiused corners
and a flanged lip adjacent thereto, The grommet is moveable in a
forward direction for insertion into the opening. The grommet
comprises a peripheral wall having corner portions and side
portions extending between the corner portions. The grommet has at
least one passageway defined therethrough within the peripheral
wall. Attachment fittings extend outwardly from at least three of
the corner portions. Each of the fittings has a seating element
extending outwardly relative to the wall and an abutment element
mounted forwardly of the seating element. Each of the seating
elements is engageable to one of (a) the web, and (b) the flanged
lip adjacent to a corner of the opening. Each of the abutment
elements is engageable to the other of (a) the web, and (b) the
lip. The abutment element is moveable to a deflected position to
permit introduction of the grommet into the opening, and biased to
move to an opposed position relative to its corresponding seating
element. The abutment and the seating element is co-operable to
capture the web and the lip therebetween. When so captured, the
abutment element in the opposed position is biased to discourage
disengagement of the grommet from the opening.
[0020] In an additional feature of that aspect of the invention,
the side portions are substantially straight and each has an inside
face. The grommet has at least one partition wall lying inwardly of
the peripheral wall to define at least one other passageway through
the grommet.
[0021] In another additional feature of that aspect of the
invention, the partition wall lies outside the largest inscribed
circle that can be constructed inside the peripheral wall.
[0022] In a further additional feature of that aspect of the
invention, the grommet has a plurality of partition walls. The
partition walls cooperate with the peripheral wall to define a
plurality of passageways through the grommet.
[0023] In a still further additional feature of that aspect of the
invention, the tide portions have respective leading portions and
trailing portions. The seating elements extend outwardly from the
corner portions adjacent the respective trailing portions and the
abutment elements have a cam face oriented outwardly from the
corner portions adjacent the respective leading portions,
[0024] In yet a further additional feature of that aspect of the
invention, the corner portions comprise an archway having a pair of
side columns and a spanning member. The abutment element depends
from the spanning member.
[0025] In yet still a further additional feature of that aspect of
the invention, the side portions extend linearly between the corner
portions. The corner portions have corner wall facings standing
outwardly of the walls such that a straight edge laid across the
corner wall facings stands clear of the side wall lying
therebetween.
[0026] In another additional feature of that aspect of the
invention, at least one of the seating elements includes an
outwardly cantilevered resilient member.
[0027] In yet another additional feature of that aspect of the
invention, the sidewalls have a trailing edge, and the trailing
edge has an outwardly extending flange formed thereon.
[0028] In yet still another additional feature of that aspect of
the invention, at least one of the seating elements is resilient.
The grommet is moveable to an inserted position relative to the
structural member. In the inserted position the abutments are able
to move to the opposed position and the resilient seating element
is pre-loaded. The pre-loaded resilient seating element is operable
to exert a rearward force on the abutments.
[0029] In a further additional feature of that aspect of the
invention, at least one of the seating elements is resilient and
has a distal tip region that is cantilevered outwardly from the
peripheral wall, The distal tip region has a forwardly protruding
formation hereon. The grommet is moveable to an inserted position
relative to the structural member. In the inserted position the
abutments are able to move to the opposed position and the
forwardly protruding formation engages the structural member to
cause the distal tip region to deflect rearwardly relative to the
peripheral wall, thereby applying a pre-load to the resilient
seating element, The pre-loaded resilient seating element is
operable to exert a rearward force on the abutments, thereby
squeezing the structural member between the abutments and the
seating elements.
[0030] In yet a Anther additional feature of that aspect of the
invention, the seating elements include flanges cantilevered out
from the peripheral wall. The flanges have a rearward face and a
distal edge, and, when installed on the structural member, the
rearward face of the cantilevered flange adjacent to the distal
edge stands rearwardly relative to the remainder of the
cantilevered flange.
[0031] In still yet a further additional feature of that aspect of
the invention, the peripheral wall has three planar side portions
and three corner fitments. An outwardly extending flange surmounts
the trailing edge of each of the side portions, the trailing face
of the flanges being coplanar. The corner portions each include an
archway having columns and an overspanning member, Each of the
columns mate with an end of an adjoining side portion and the inner
face of the arch has a skirt mounted thereacross, A resilient catch
member is mounted to depend from the arch. The abutment is a
rearwardly facing surface of the catch member. The catch member has
an outwardly and rearwardly tapering cam surface. The cam surface
is moveable to deflect the abutment inwardly. The columns are
mounted to stand outwardly of the side wall portions to define a
clearance rebate therebetween. The seating element includes a
cantilevered flange extending outwardly about the corner portion
and mating with the outward flanges of the trailing portions of the
side wall portions. The cantilevered flange is resilient, In
another aspect of the invention, there is the combination of at
least one beam-like longitudinally extending structural member, and
at least one grommet for use in cooperation therewith. The
structural member has a web. The web has a longitudinal edge, and a
longitudinally extending main flange running along the edge. The
web has at least one opening therein, and flangework formed
adjacent to the opening. The grommet has a peripheral wall having
an internal face defining a passageway. The wall has a leading
portion that can be introduced into the opening in the web, and a
trailing portion having at least one seating element extending
outwardly of the wall to prevent passage of the trailing portion
fully through the opening. The grommet has at least one biased
member having an abutment element biased to an opposed position
relative to the seating element. The biased member is moveable to a
deflected position during introduction of the trailing portion into
the opening. The grommet is moveable to engage the seating element
against one of (a) the flangework and (b) the web, and, when so
engaged the abutment element is moveable to the opposed position
under the influence of the biased member. In the opposed position
the abutment element discourages removal of the grommet from the
opening.
[0032] In still another additional feature of that aspect of the
invention, the opening has a periphery defined in the web. The
peripheral wall has at least one side wall portion extending
between a pair of sidewall ends. One of the seating elements and
one of the abutment elements are located at each end thereof and,
in an installed position of the grommet relative to the structural
member the side wall portion has a span free of contact with the
periphery of the opening.
[0033] In yet another additional feature of that aspect of the
invention, the structural member has a pair of opposed main flanges
extending along opposite edges of the web. A plurality of the
openings are formed in the web. Each of the openings has a base
side portion extending parallel to one of the main flanges and a
pair of side portions extending from the base side to meet at a
smoothly radiused apex opposite the base side portion. The openings
are arranged along the web in alternating side-by-side fashion with
alternating diagonally extending struts formed in the web between
pair of adjacent openings. The flangework extends along the and the
base side portions.
[0034] In still yet another additional feature of that aspect of
the invention, the opening has a base side portion extending
parallel to the main flange and a pair of side portions extending
from the base side to meet at a smoothly radiused apex opposite the
base side portion. The side portions and the base portion of the
opening meet at smoothly radiused base corners. The grommet engages
the flangework at the base corners and at the apex.
[0035] In another additional feature of that aspect of the
invention, the grommet has a base portion locatable adjacent the
base portion of the opening and a pair of side portions locatable
adjacent to the side portions of the opening The base portion and
the side portions of the grommet meet at respective attachment
fittings that seat in the corers and the apex of the opening.
[0036] In still yet another additional feature of that aspect of
the invention, the flangework forms a continuous peripheral lip
around the opening.
[0037] In a further additional feature of that aspect of the
invention, the apex has a larger radius of curvature than either of
the base corners.
[0038] In yet a further additional feature of that aspect of the
invention, the web lies in a web plane. Portions of the flangework
extend about the corners and the apex of the openings. The portions
of the flangework have respective distal edges formed out of the
plane of the web at a tapered angle whereby the entrance of the
opening at the plane of the web is wider than the exit of the
opening adjacent the distal edges. The leading portion is moveable
along an insertion direction running from the entrance toward the
exit of the opening.
[0039] In still yet a further additional feature of that aspect of
the invention, the attachment fittings have column members shaped
to conform to the taper of the flangework at the corners and at the
apex.
[0040] In another additional feature of that aspect of the
invention, each attachment fitting includes one of the abutments,
one of the seating elements, and has a pair of the column members
and an overspanning member attached thereto adjacent the leading
portion of the grommet. Each attachment fitting has an arm
depending from the overspanning member. The arm has the abutment
formed thereon, and has an outwardly facing cam member engageable
with the taper of the flangework to cause the abutment to deflect.
In the opposed position the abutment engages the distal edge of the
flangework.
[0041] In yet another additional feature of that aspect of the
invention, each of the seating elements has an outwardly extending
resilient wing. The resilient wing waves an interface member for
engaging the web. The resilient member is operable to exert a
rearward force on the abutment when the grommet is engaged with the
structural element.
[0042] In a further additional feature of that aspect of the
invention, the grommet includes at least one internal partition to
define a plurality of passageways therethrough.
[0043] In a still further aspect of the invention, there is a kit
comprising at least one sheet metal structural member and at least
one grommet for use in co-operation therewith. The sheet metal
structural member has a pair of opposed, spaced apart, parallel
main flanges and a web extending therebetween. The web has an outer
face lying predominantly in a web plane and an inner face lying to
one side thereof The main flanges extend perpendicularly to the web
plane and away from the outer face, to give the sheet metal
structural member a C-shaped appearance when viewed from one end
thereof The web has a plurality of triangular openings formed
therein in an alternating arrangement, and a plurality of
alternating, flanged diagonal struts formed between adjacent pairs
of the openings. The openings have smoothly radiused corners, The
web has lip flangework formed therein adjacent each opening. The
lip flangework stands proud of the inside face of the web. The
grommet has a peripheral wall having an internal face defining a
passageway. The wall has a leading portion that can be introduced
into one of the openings in the web, and a trailing portion having
at least one seating element extending outwardly of the wall to
prevent passage of the trailing portion fully through the one
opening. The grommet has at least one biased member having an
abutment surface biased to an opposed position relative to the
seating element. The biased element is moveable to a deflected
position during introduction of the trailing portion into the one
opening. The abutment element and the seating element defines a
capture depth at least great enough to capture the lip flangework
and the outer face therebetween when the seating element engages
the sheet metal structural member and the abutment surface moves to
the opposed position.
[0044] In an additional feature of that aspect of the invention,
the lip flangework is continuous flange extending about the
triangular opening.
[0045] In a further additional feature of that aspect of the
invention, the smoothly radiused corners of adjacent openings
define root portions of the struts adjacent the corners. The
grommet has three seating elements and three biased members, spaced
about the peripheral wall in positions to engage the sheet metal
structural member adjacent the smoothly radiused corners of the
opening.
[0046] In yet a further additional feature of that aspect of the
invention, portions of the flangework extend about the corners and
apex of the opening. The portions of the flangework have respective
distal edges formed out of the web plane at a tapered angle such
that the entrance of the opening at the plane of the web is wider
than the exit of the opening adjacent the distal edges. The leading
portion is moveable along an insertion direction running from the
entrance toward the exit of the opening. The grommet has attachment
fittings locatable in the corners and the apex of the opening. The
attachment fittings have column members shaped to conform to the
taper of the flangework at the corners and at the apex.
[0047] In still yet a further additional feature of that aspect of
the invention, portions of the flangework extend about the corners
and the apex of the opening. The portions of the flangework have
respective distal edges formed out of the web plane at a tapered
angle such that the entrance of the opening at the web plane is
wider than the exit of the opening adjacent the distal edges. The
grommet includes attachment fittings engageable with the structural
member adjacent the corners and apex of the opening. Each of the
attachment fittings includes one of the abutments, one of the
seating elements, has a pair of the column members and an
overspanning member attached thereto adjacent the leading portion
of the grommet. Each attachment fitting has an arm depend from the
overspanning member.
[0048] The arm has the abutment formed thereon, and has an
outwardly facing cam member engageable with the taper of the
flangework to cause the abutment to deflect. In the opposed
position the abutment engages the distal edge of the
flangework.
[0049] In yet another additional feature of that aspect of the
invention, each of the seating elements has an outwardly extending
resilient wing, The resilient wing waves an interface member for
engaging the web, and the resilient member is operable to exert a
rearward force on the abutment when the grommet is engaged with the
structural element.
[0050] In a further additional feature of that aspect of the
invention, the peripheral wall has corner portions and straight
side portions extending between the corner portions. The corner
portions have corner wall facings standing outwardly of the walls
such that a straight edge laid across the corner wall facings
stands clear of the side wall lying therebetween.
[0051] In yet a further additional feature of that aspect of the
invention, the grommet has at least one partition wall lying
inwardly of the peripheral wall to define at least one other
passageway through the grommet.
[0052] In another aspect of the invention, there is the combination
of at least one beam-like structural member that extends in a
longitudinal direction, and at least one grommet for use in
co-operation therewith. The structural member has a planar web. The
web has a straight longitudinal edge, and a longitudinally
extending main flange running along the edge. The web has a
plurality of alternating wide portions and narrow portions defining
a longitudinal zig-zag edge. The web has an opening defined in each
of the wide portions. Each opening has a base portion parallel to
the edge and a pair of side portions extending away from the base
portion to meet at an apex. The opening has smoothly radiused
corners between the base portion and the side portions, and at the
apex. The structural member has a lip flange formed about the
opening. The lip flange has a distal edge lying away from the web.
The grommet has a peripheral wall having an internal face defining
a passageway. The wall has a leading portion that can be introduced
into the opening in the web, and a trailing portion having at least
one seating element extending outwardly of the wall and engageable
with the web to prevent passage of the trailing portion fully
through the opening. The grommet has at least one biased member
having an abutment element biased to an opposed position relative
to the seating element. The biased member is moveable to a
deflected position during introduction of the trailing portion into
the opening. The grommet is moveable to engage the seating element
with the web and the abutment element with the lip flange to
capture the web. In the opposed position the abutment element
discourages removal of the grommet from the opening.
[0053] In an additional feature of that aspect of the invention,
the opening has a generally isosceles triangular shape, dividing
the wide portion into a pair of strut-like portions. The peripheral
wall has three straight side portions and three corner fittings.
One of the corner fittings is sized to fit the apex, and the other
two of the fittings is sized to fit the other two corners of the
opening. The corner fittings stand proud of the side portions such
that a straight edge placed across any two of the fittings stands
clear of the straight side portion lying therebetween.
[0054] In a further additional feature of that aspect of the
invention, the fittings each include one of the abutment and one of
the seating elements, and the fittings act against the web and the
lip flange at the corners of the opening In yet a further
additional feature of that aspect of the invention, an outwardly
extending flange surmounts the trailing edge of each of the side
portions, The trailing face of the flanges is co-planar. The
seating element includes a cantilevered flange extending outwardly
about the corner portion and mating with the outward flanges of the
hailing portions of the side wall portions. The cantilevered flange
is resilient and has a portion engageable with the web. The corner
portions each include an archway having columns and an overspanning
member, each of the columns mates with an end of an adjoining side
portion and the inner face of the arch has a skirt mounted
thereacross. A resilient catch member is mounted to depend from the
arch, The abutment is a rearwardly facing surface of the catch
member, The catch member has an outwardly and rearwardly tapering
cam surface. The cam surface is moveable to deflect the abutment
inwardly. The grommet is movable to a seated position relative to
the structural member, and, in the seated position the resilient
member bears against the web under a pre-load and carries and
exerts a force to urge the abutment to bear against the distal edge
of the lip flange.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] FIG. 1a is a general arrangement, perspective view of a pair
of sheet metal structural members of different sizes each grommets
mounted therein according to the principles of the present
invention; with additional small and large grommets shown in the
foreground;
[0056] FIG. 1b is a cross-sectional view of a strut of one of the
structural members of FIG. 1a taken on section `1b-1b`;
[0057] FIG. 1c is a partial cross-sectional view of a corner
portion of one of the structural members of FIG. 1 taken on
`1c-1c`;
[0058] FIG. 2a is an isometric view of the large grommet of FIG.
1;
[0059] FIG. 2b is a plan view of the grommet of FIG. 2a;
[0060] FIG. 2c is a plan view of the grommet of FIG. 2a taken
opposite to FIG. 2b;
[0061] FIG. 2d is a detail view of the grommet of FIG. 2a taken on
arrow `2d`;
[0062] FIG. 3a is a side view, in section, of the grommet of FIG.
2a as it is about to enter an opening in a structural member;
[0063] FIG. 3b is a side view, in section, of the grommet of FIG.
2a as it is being introduced into the opening of FIG. 3a;
[0064] FIG. 3c is a side view, in section, of the grommet of FIG.
2a in a seated position relative to the structural member of FIG.
3a;
[0065] FIG. 4a shows a plan view similar to FIG. 1b of an alternate
embodiment of grommet having internal partitions;
[0066] FIG. 4b shows a further alternative embodiment to the
grommet of FIG. 2b;
[0067] FIG. 4c shows another alterative embodiment to the grommet
of FIG. 2b;
[0068] FIG. 4d shows yet another alternative embodiment to the
grommet of FIG. 2b;
[0069] FIG. 5b shows a top plan view of the small grommet of FIG.
1a;
[0070] FIG. 5b shows a bottom plan view of the grommet of FIG.
5a;
[0071] FIG. 5c shows a cross-section of the grommet of FIG. 5a on
section `5c-5c`;
[0072] FIG. 6a shows a side view of an alternate embodiment of
structural member to the structural member of FIG. 1;
[0073] FIG. 6b shows a cross-sectional view of the structural
member of FIG. 6a;
[0074] FIG. 7a shows a side view of another alternate embodiment of
structural member to the structural member of FIG. 1;
[0075] FIG. 7b shows a sectional view of the structural member of
FIG. 7a;
[0076] FIG. 8a shows a side view of another alternate embodiment of
structural member to the structural member of FIG. 1;
[0077] FIG. 8b shows a sectional view of the structural member of
FIG. 8a;
[0078] FIG. 9a shows an alternate cross-section to the cross
section of FIG. 3a;
[0079] FIG. 9b shows another alternate cross-section to the
cross-section of FIG. 3a;
[0080] FIG. 9c shows a further alternate cross-section to the
cross-section of FIG. 3a;
[0081] FIG. 10a shows a side view of another alternate embodiment
of structural member to the structural member of FIG. 1;
[0082] FIG. 10b shows an isometric view of a pair of structural
members as in FIG. 10a with tips embedded in concrete;
[0083] FIG. 10c is a detail of a flanged opening and embedment
formation of the structural member of FIG. 1a;
[0084] FIG. 11a shows an alternate cross-section for the structural
member of FIG. 10a;
[0085] FIG. 11b shows another alternate cross-section for the
member of FIG. 10a;
[0086] FIG. 11c shows a further alternate cross-section for the
member of FIG. 10a;
[0087] FIG. 12a shows a side view of a pair of structural elements
joined together; and
[0088] FIG. 12b shows a cross-sectional view of the elements of
FIG. 12a.
DETAILED DESCRIPTION OF THE INVENTION
[0089] The description which follows, and the embodiments described
therein, are provided by way of illustration of an example, or
examples of particular embodiments of the principles of the present
invention, These examples are provided for the purposes of
explanation, and not of limitation, of those principles and of the
invention. In the description which follows, like parts are marked
throughout the specification and the is drawings with the same
respective reference numerals. The drawings are not necessarily to
scale and in some instances proportions may have been exaggerated
in order more clearly to depict certain features of the
invention,
[0090] Referring to FIGS. 1a, 3a, 3b, and 3c, a sheet metal
structural member is indicated generally as 20. It has a web 22 and
a pair of generally opposed, longitudinally extending parallel main
flanges 24 and 26 that extend perpendicularly out of the plane of
web 22 to form a generally `C` shaped channel section, with the
toes of flanges 24 and 26 having an inwardly bent lip 28, 30. In
the example of FIG. 1, member 20 has width and depth dimensions to
simulate a (nominal) 2".times.6", although 2".times.4" studs (seen
in the background of FIG. 1 and indicated as 32), 2".times.8" beams
or other stud or beam sizes can also be formed. Web 22 can be
termed the back of the C-channel section, and lies, generally, with
its outer face 34 in a web plane indicated as `W`. The inner face
36 of web 22 lies to one side of web plane `W`, and the legs of the
section, main flanges 24 and 26, extend to the same side of plane
`W`, The longitudinal direction is indicated by an `X`, the axial
direction perpendicular to `X` and lying in plane `W` is indicated
as `Y` and the axial direction perpendicular to plane `W` is
indicated as `Z`, The width of web 22, and the overall depth of
structural member 20, are measured in the `Y` direction, and the
width of main flanges 24 and 26 is measured in the `Z`
direction.
[0091] Web 22 of member 20 has been blanked and formed to leave an
array 38 of alternating diagonal struts 40 and 42 that extend
between web margins 44 and 46 whence flanges 24 and 26 extend.
Openings, of which one representative example is indicated as 48,
are defined in the spaces bounded by respective diagonal struts 40
and 42, and margins 44 and 46, as the case may be.
[0092] A one-piece, snap fit grommet 60 is mounted to member 20 by
being pushed into opening 52 in the insertion direction indicated
by arrow `P`, Opening 52 is, for the purposes of this description,
identical to any one of openings 48, 50 or 54, such that grommet 60
could be mounted in any of them, interchangeably, Grommet 60
provides a protected port for services, such as a water pipe or
electrical conduit or cable (not shown) to traverse web 22.
[0093] Opening 48, being typical, will now be described in detail.
It has a generally triangular shape, having a first radiused corner
defined at the altitudinal vertex, or apex 62, lying between struts
40 and 42, a second, radiused base corner 64 lying between strut 40
and margin 44, and a third, radiused corner 66 lying between strut
42 and margin 44. In general, the triangular shape so defined is an
isosceles triangle The radius at base corners 64 and 66 is smaller
than the larger, more generous radius of apex 62. As shown, the
base 68 of the triangular shape lies along margin 44. Bases 67 and
69 of the adjacent triangular openings, indicated as 50 and 54, lie
along the margin 46, each triangle alternating in orientation
relative to its neighbours.
[0094] Flangework, in the nature of a continuous rim, or lip flange
70 is formed out of the plane of web plane `W` in the direction
away from outer face 34, and extends fully about the periphery of
opening 48. Lip flange 70 includes left and right hand strut
flanges 72, 74 that extend along the sides of struts 40, 42 and a
base side flange 76 formed on mar&i 44 (similar flanges extend
along the sides of the adjacent opening, 50). In each of base
corners 64 and 66 there is a corner flange portion 80, 82 whose
free edge 84, 86 lies at a shallower depth than the free edge of
flanges 72 or 74, and at a shallower depth than the free edge of
the medial portion 88 of flange 76. Lip flange 70 also includes an
apex flange 87 which runs along apex 62 and smoothly into strut
flanges 72 and 74.
[0095] Each of struts 40 and 42 has a medial portion 90 and root
portions 92, 94 at either end. In each of root portions 92, 94
there is a generally triangular indentation 96, 98 stepped to one
side of plane `W` of web 22 generally. Each of indentations 96, 98
has a generally straight base side 100, another side 102 facing the
altitudinal vertex of the adjacent opening, and a curved side 104
sharing a center of curvature with base corner 64 or 66 as the case
may be. In section, medial portion 90 has a back 106 lying in the
plane of web 22 generally, and a pair of formed legs, being flanges
72 and 73 in the case of strut 40, and flanges 74 and 75 in the
case of strut 42.
[0096] Flanges 72 and 73 (and 74 and 75) lie at an out-of-plane
true angle to the plane of web 22 generally that is indicated by
.alpha. such that flanges 72 and 73 present a tapered wall that has
a root at back 106 and a distal edge lying away from web `W`. By
comparison, corner flange portion 80 (and 82) is formed on an angle
.beta. to extend away from plane `W` and presents a tapering
surface with a distal edge 84, .beta. being less than .alpha..
[0097] Grommet 60 also is shaped to conform, generally, to the
shape of opening 48 (or 50, 52, 54 as shown). Grommet 60 has a
peripheral wall 110 having a base side 112, base corners 114 and
116, a pair of sides 118 and 120 rising toward an altitudinal
corner, or apex 122. As such it has a general shape in plan view of
an isosceles triangle, with truncated corers, Attachment fittings
124, 126 and 128 are located at respective corners 114, 116 and
apex 116. Peripheral wall 110 has a forward or leading portion,
130, that is, the portion that is first introduced into opening 48
during insertion of grommet 60, and a rearward or trailing portion
132 that follows the leading portion during insertion.
[0098] Each of sides 112, 118 and 120 has a cross-section as shown
in FIG. 3a. Each has a side wall or leg, 134 that is generally
rectangular in section, and a trailing edge flange 135 extending
perpendicularly relative to leg 134. Leg 134 is slightly tapered,
having a draft angle to facilitate removal from the mold on
manufacture. Leg 134 has an inner face 136 that faces inwardly
toward, and defines a portion of the boundary of, an internal
passageway 140. Internal passage 140 extends generally in the
direction of insertion indicated by arrow `A`, and is formed to
carry services through web 22, such as plumbing wiring, vacuum
hoses, or other hardware. Leg 134 also has an external, or outer
face 138 that faces outward relative to passageway 140.
[0099] Corners 114 and 116 are right and left hand images of each
other, If sides 112, 118, and 120 were extended they would meet at
a sharp corner, Instead they are truncated at the respective corner
fittings. At the points where sides 112, 118 and 120 are truncated
in this way, grommet 60 has corner webs 142, 143, and 144 which
form part of, and complete, the boundary of passageway 140 formed
by peripheral wall 110.
[0100] For the purposes of description, attachment fitting 128 at
apex 122 differs from attachment fittings 124 and 126 only in size,
corner radius, aspect ratio and other dimensions rather than in
nature. Thus, although only one fitting is described, the
description is applicable to the fittings as well.
[0101] Each attachment fitting has an archway 146 having a pair of
left and right hand columns 147 and 148 surmounted by an
overspanning member in the nature of a lintel 150 that surmounts
the distal ends of columns 147 and 148 and has a forward surface
lying flush with the leading edge 152 of peripheral wall 110.
Columns 147 and 148 stand outwardly from peripheral wall 110. That
is, the inner edge of columns 147 and 148 back on the adjacent
sidewall portions while their outer left and right hand edge
facings 153 and 154 stand outwardly of the planes defined by outer
faces 138 of the respective wall portions. In side view, as seen in
the detail of FIG. 2d, the leading portion of column 147 (and 148)
has a rake angle .psi. such that column 147 (or 148) is wider at
its base than at its distal end. A straight edge placed across a
pair of columns at either end of any of side portions 112, 118 or
120 will stand clear of their respective outer faces, 138. That is,
a rebate 156 formed between outer surface 138 and the columns at
either end thereof
[0102] Further, facings 153 and 154, and the outward edge of lintel
150 are formed to conform to an arcuate surface, such that the
leading end of grommet 60 can be introduced into opening 52, and so
that facings 153 and 154 seat in the smoothly curved corners of,
for example, opening 48, 50, 52 or 54.
[0103] Each attachment fitting 124, 126, or 128 includes a catch
member 160 that depends from lintel 150. It has an outwardly
oriented tapered facing, in the nature of a fluted cam face 162,
the taper being such that the depending edge 164 is biased to stand
further outwardly than facings 153 and 154. A shoulder, in the
nature of a rearwardly facing abutment 166 extends inwardly from
edge 164 to terminate at a rearwardly extending depending skirt, or
tab 168 of catch member 160, In operation, when grommet 60 is moved
forward along the insertion direction, cam face 162 will tend to
engage the arcuate tapering surface of one or another of corner
flange portions 80, 82 and apex flange 87. This will in turn tend
to cause catch member 160, and hence abutment 166 to deflect
inwardly into the alcove, or chamber, defined inside archway 146.
Catch member 160 is resilient, and is biased outwardly. When
grommet 60 is advanced sufficiently far for edge 164 to clear the
distal edge 169 of the respective corner flangework, abutment 166
is able, under the bias of catch member 160, to move outwardly to
engage distal edge 169. In this outward position abutment 166
discourages rearward movement of grommet 60, preventing its removal
from opening 52.
[0104] Each attachment fitting 124, 126 or 128 also includes a
seating element 170 in the nature of an outwardly extending
cantilevered wing 172 that has a pair of left and right hand flange
extensions 174 and 176 that lie flush with, and are smoothly rooted
into flanges 135, of peripheral wall 110. An arcuate bridging
member 178 lies in the same plane as, and connects the distal ends
of, flange extensions 174 and 176. As thus arranged the trailing
edge of web 142, 143, or 144 as the case may be, the inside edge of
flange extensions 174 and 176, and the inside edge of bridging
member 178 define a port 179 through which mold extensions may move
during fabrication of grommet 60 to form the underside of lintel
150 and the inward or rearward face of catch member 160.
[0105] On the leading face of each seating element is a forwardly
protruding nub 180 that engages the outer face 34 of web 22 when
grommet 60 is inserted. Seating element 170 is resilient. When the
trailing face of grommet 60 is pushed forward enough to cause
abutment 166 to snap into position, the forward motion also causes
nub 180 to seat against web 22, and, in so doing, a pre-load is
applied to seating element 170, In this position abutment 166 sits
in a position that is generally opposed to seating element 170 and
the space between them, measured in the direction of insertion, is
sufficient to permit capture of apex flange 87 (or flange portions
80 or 82 as the case may be) and web 22. When grommet 60 is left in
place, the preload in seating element 170 will tend to bias
peripheral wall 110 rearward relative to the insertion direction,
and in so doing, will tend to exert a force to urge abutment 166
more firmly against distal edge 169, thus tending to immobilise
grommet 60. This preload may also tend to help grommet 60 resist
loosening and rattling under modest vibration.
[0106] When grommet 60 is seated in this way in opening 48, 50, 52
or 54, the outer faces 138 of leg 134 of each of the three sides of
peripheral wall 110 will stand clear of the corresponding facing
portions of flangework lip flange 70. This increases the likelihood
that vibration loads will not be transferred to or from the mid
sections of the struts, but rather will be carried to the corners
at margins 44 and 46.
[0107] In alternative embodiments, other geometric arrangements of
seating element can be used. For example, flange extensions 174 and
176 could be curled forward to present a leaf-spring-like
arrangement for deflection on insertion. Not all of the seating
elements need be resilient. In some cases it may not be desirable
to have any pre-loaded seating elements, in others a single
pre-loaded element or spring would suffice to pre-load all of the
fittings. For example, although the configuration shown in FIGS.
2a, 2b and 2c is preferred, a grommet having a pair of abutments
(or seating elements) located at the mid-portion of the long sides
118 and 120 could be opposed by a pair (or more) of seating
elements (or, abutments) arranged in the corners, or one at apex
122 and one along the middle of the base side 112. A single spring
loaded element, among a total of four seating elements and
abutments, would then serve to preload all of the others.
[0108] In an alternative embodiment as shown in FIG. 4a, a grommet
181 has three internal dividers 182, 184, and 186 that, subdivide
the space enclosed within a peripheral wall 188, similar in other
respects to peripheral wall 110 described above. An allowable
maximum outer pipe diameter .phi. is defined by the largest
circular section that can be inscribed within side wall portions
192, 194 and 196, and is shown in dashed lines in main passageway
198. (It will be appreciated that a slightly larger pipe can be
carried, or the enclosure of peripheral wall 188 can be made
slightly smaller, if an interference fit is desired.) As
illustrated, each of dividers 182, 184 and 186 is located outside
the circle of diameter .phi., and the subsidiary passages so
formed, indicated as 200, 202 and 204, are available to carry other
services, Dividers 182, 184, and 186 need not be straight walls, or
webs, but could be formed on a circular arc, as shown at 206 in
FIG. 4b. Alternatively, as shown in FIG. 4c a spider 208 having a
circular center 210, such as may be suited to a water pipe, and
outwardly radiating partitions in the nature of dividers 212 could
be used. One or two dividers could be used rather than three as
shown, or more dividers could be used depending on the number,
shape and size of the passageways to be formed. In FIG. 4d a single
divider 214 divides the internal passageway into a minor section
216 for a pipe 217 (shown in dashed lines) and a major portion 218
for other services. Divider 214 is bent so that the long sidewalls
of the grommet can be squeezed inward to flex divider 218, and,
when released it holds snug against pipe 217,
[0109] Grommet 60 is a molded pant made from a polypropylene
homopolymer plastic. It is considered to be and may tend to
function as an electrical insulator. The edges of grommet 60 that
face inward toward passageway 140, or that stand rearwardly of web
22 when installed, have a small radius (typically 0.047") to
decrease the likelihood that service conduits or cables passing
through grommet 60 will encounter a sharp edge. In the specific
embodiment illustrated in FIG. 2a, grommet 60 is of a size to fit
an opening in a (nominal) 2.times.6 member.
[0110] Alternative sizes of grommet can also be made, as typified
by grommet 220 shown in the foreground of FIG. 1a, and installed in
the (nominal) 21".times.4" structural member 38 lying in the
background of FIG. 1a. Grommet 220 is shown in top, bottom and
sectional views in FIGS. 5a, 5b and 5c respectively. It has
attachment fittings 222, 224, and 226 of the same nature and
features as attachment fittings 124, 126 and 128. Openings 230,
232, and 234 defined in web 236 of structural member 38 have the
same pitch between centers as openings 48, 50, 52 and 54 described
above, but a shallower height, reflecting the shallower depth of
section of member 38 as compared to member 20. Grommet 220 differs
from grommet 60 primarily in the ratio of its altitude, or height,
in plan view, as measured from base sidewall 238 to apex 240. Thus
sidewalls 242 and 244 are each shorter than base sidewall 238,
whereas base sidewall 112 is the shortest side of grommet 60. A
similar lengthening or shortening of aspect ratio permits a family
of grommets to be manufactured suitable for a family of structural
members sharing the same pitch between adjacent through-web
openings.
[0111] Although structural member 22, as shown in FIGS. 1a, 1b, and
1c is preferred, other arrangements of flangework could be
presented. For the purposes of the present invention it is not
necessary that the flangework extend fully and continuously about
the entire periphery of the opening. The flangework could, for
example, extend only along the sides of the struts, and in the
strut root portions, The flangework can be of varying height, or
depth, about the periphery. The flangework can taper from a deepest
section at the mid span of the struts to shallower portions
adjacent the roots, or to taper into no flange at all, or could be
formed only at the roots.
[0112] For example, in FIGS. 6a and 6b a structural member 250 has
a lip flange 252 that is less sharply angled from web plane `W`
that that of structural member 20. The openings defined in
structural member 250 are more sharply triangular than opening 48,
having the form of equilateral triangles with a common radius of
curvature at each corner. The radius at the free edge of the corner
flange portions 254 is larger than at the plane of web `W`,
yielding a relatively large, relatively shallowly angled corner web
256.
[0113] In FIGS. 7a and 7b a structural member 260 is similar to
structural member 250, except insofar as it employs a steeper
corner flange portion 262. In FIGS. 8a and 8b a relatively heavy
section structural member 270 had formed flanges 272 and 274, and a
deeper lip flange 274, than member 250. In FIG. 9a a structural
member 276 has a lip flange 278 that is formed outwardly of the
section, rather than inwardly as in FIG. 3a., such that the
insertion direction of grommet 60 would tend to be reversed. In
FIG. 9b a structural member 280 has asymmetric main flanges 282 and
284. In FIG. 9c a structural member 286 has one flange 288 formed
to one side of web plane `W`, and another flange 290 formed to the
other side. Grommets such as grommet 60 or grommet 220, depending
on the size required, can be installed to co-operate with each of
the illustrated sections noted above.
[0114] Further, although the preferred form of opening, and of
grommet, is a form that is generally similar to an isosceles
triangle with rounded corners, other shapes could be used, For
example, a trapezoidal opening between the opposed margins of the
web and a pair of diagonally inclined struts is also possible. As
the radius of curvature of the apex corner increases, the resultant
opening tends to take on a `D`-shaped appearance in plan view,
particularly as the width of section increases relative to the base
dimension of the opening, or as the radius of the apex approaches
half the length of the base side. In general, the opening has a
base portion adjacent to one margin of the web, and a pair of side
portions that extend away from the base portion to meet at an apex
adjacent to the other margin of the web.
[0115] Another type of roll-formed structural member is shown in
FIGS. 10a and 10b as 300. It has a web 302 having wide portions 304
alternating with narrow portions 306 to give a saw-toot, or zig-zag
appearance. One edge 308 of web 302 is straight while the other
edge 310 undulates. Along edge 308 member 300 has a longitudinal
main flange structure 312. Along undulating edge 310 member 300 has
a lip, or edge reinforcement flange 314 extending perpendicular to
the plane of the web. Triangular openings 316 are defined centrally
in each of the wide portions of web 302, each triangular opening
316 having a peripheral flange 318 and smoothly radiused base and
altitudinal corners 320, 322 and 324. Each triangular opening tends
to divide its respective wide portion into a pair of tapering
triangular struts 326 and 328 that meet at a point 330. The flange
314 acts as an embedment formation for point 330, but in addition
point 330 also has defined in it, adjacent flange 314, an aperture
332 through which a cast material such as concrete can flow.
Further, as shown in FIG. 10c, the embedment formation can include
a tongue 334 that extends laterally from the web in the opposite
direction from flange 314, and can be formed from the blanked-out
material removed to form aperture 332. As illustrated in FIG. 10a,
the tip of point 330 is embedded in cast material 336 to a level
lying between flange 314 and the attitudinal corner of flange 314.
A grommet, such as grommet 60 or grommet 220, with suitable
adjustments for size of opening and depth of flange to be captured,
can be seated in opening 316. As such services carried through the
grommet are carried in a controlled position, through the web, at a
position between main flange 312 and flange 314, through the
controlled geometry of opening 316, The geometry of opening 316 is
controlled in the sense that it is determined by the shape of dies
in a rotary press as the point of manufacture of the structural
member. There may tend to be much less control over the dimension
between flange 314 at the narrow throat 338 and the cast
material.
[0116] Main flange 312 can be formed in a variety of
configurations. As shown in FIG. 11a The main flange can be a
triangular element 340, or other tube shape, whether circular of
polygonal. As shown in FIG. 11b, the main flange 342 can be more or
less channel-shaped, with a relatively large outboard leg 344. As
shown in FIG. 11c a main flange 346 can be a main flange 348 can be
formed in the shape of an angle iron with a main leg 350 parallel
to the cast material, and a small lip 352 at the outboard distal
extremity. In FIG. 12a and 1b, a pair of structural members 360 and
362 having undulating edges are mounted back-to-back to form a beam
having a pair of parallel main flanges 364 and 366. As above, each
has an opening 368 with a formed lip 370 to which a grommet such as
grommet 60 or 220 can mount, thereby providing a controlled
dimension protected passageway for carrying services.
[0117] Various embodiments of the invention have now been described
in detail. Inasmuch as changes in and or additions to the
above-described best mode may be made without departing from the
nature, spirit or scope of the invention, the invention is not to
be limited to those details, but only by the appended claims.
* * * * *