U.S. patent number 3,815,638 [Application Number 05/069,163] was granted by the patent office on 1974-06-11 for duct frame opening.
Invention is credited to Duane P. Martin.
United States Patent |
3,815,638 |
Martin |
June 11, 1974 |
DUCT FRAME OPENING
Abstract
A duct opening frame, typically supplied in coil form, of
flexible, bendable sheet material and adapted to be formed into a
frame for attachment to low density, Fiberglas heating, ventilating
and cooling ducts to provide means to receive grilles, registers
and access doors on the duct.
Inventors: |
Martin; Duane P. (Minneapolis,
MN) |
Family
ID: |
26749752 |
Appl.
No.: |
05/069,163 |
Filed: |
September 2, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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642634 |
May 11, 1967 |
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Current U.S.
Class: |
138/103;
454/331 |
Current CPC
Class: |
F16L
45/00 (20130101); F16L 25/0009 (20130101); F24F
13/06 (20130101); F24F 13/0263 (20130101) |
Current International
Class: |
F24F
13/02 (20060101); F24F 13/06 (20060101); F16L
25/00 (20060101); F16L 53/00 (20060101); F16l
053/00 () |
Field of
Search: |
;29/190,183,193 ;285/424
;98/114,101 ;165/50 ;138/103 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myracle; Jerry W.
Attorney, Agent or Firm: Williamson, Bains & Moore
Parent Case Text
This is a continuation of Ser. No. 642,634, filed May 11, 1967, now
abandoned.
Claims
What is claimed is:
1. In combination with an elongate generally rectangular fiberglass
duct having a continuous closed peripheral wall, a rectangular
opening in the peripheral wall,
a single piece metallic duct opening frame including a
substantially rectangular collar having opposed substantially
parallel pairs of walls, each wall having an inner edge and an
outer edge, said collar being positioned within and fitting snugly
in engaging relation within the rectangular opening in the
fiberglass duct, each wall of said collar having a dimension from
the inner edge thereof to the outer edge thereof corresponding to
the thickness dimension of the peripheral wall of the fiberglass
duct,
each wall of said collar having a plurality of uniformly spaced
apart ducts engaging tabs integral with the inner edge thereof and
each being bent to extend outwardly at substantially right angular
relation from a fold line along the inner edge to engage the
interior surface of the fiberglass duct, a plurality of spaced
apart openings in said collar each being located along the fold
line of one of said tabs,
each wall of said collar having an elongate substantially flat
generally rectangular shaped flange integral with the inner edge
thereof and being bent to extend outwardly at substantially right
angular relation from a fold line along said outer edge for
engaging the exterior surface of the fiberglass duct to clamp the
wall of the duct between the tabs and the flanges, each flange
having a plurality of spaced apart elongate apertures therein, a
plurality of spaced apart openings in said collar, each of said
last-mentioned openings being located along the fold line of one of
said flanges,
an accessory frame positioned against said collar,
a plurality of similar press clips securing said accessory frame to
said collar, each press clip including a generally flat receiving
element, a pair of web elements integral with said receiving
element and extending at substantially right angular relation
thereto, one of said web elements engaging the accessory frame and
the other web element and receiving element engaging the duct, a
pair of duct engaging points each being integral with and extending
angularly from one of said web elements for penetrating the
fiberglass duct, and openings in the press clip registering with
openings in the flanges of the collar and the accessory frame.
2. The combination as defined in claim 1 wherein the receiving
element of each press clip is of substantially rectangular
configuration and wherein the web elements of each press clip are
of substantially rectangular shaped configuration.
Description
This invention relates to a duct opening frame for Fiberglas
heating, ventilating and air conditioning ducts and, more
particularly, relates to a duct opening frame of flexible, bendable
sheet material typically supplied in coil form to be formed to
order with conventional tools and by hand.
Although low density materials, such as Fiberglas, have been
available and used for the past several years for heating,
ventilating and air conditioning ducts, a suitable frame for
attachment to the duct opening to provide means to receive
registers, grilles and access doors thereon has not heretofore been
available. My co-pending application, entitled METHOD AND APPARATUS
FOR SUPPORTING AND RETAINING LOW DENSITY WEBS, Ser. No. 494,561,
filed Oct. 11, 1965, now Pat. No. 3,712,649, discloses and claims
supporting and joining apparatus for Fiberglas ducts providing a
method and means to fabricate a continuous duct system from
Fiberglas material. It has been found, however, that in addition to
means for joining and retaining Fiberglas into a continuous duct
system, a frame adapted to be attached to an opening in the duct to
provide means to receive grilles, registers and access doors
thereon has become necessary to the proper and efficient use of
Fiberglas or other low density material in a duct system.
Heating, ventilating and air conditioning duct systems require
openings therein along the system at predetermined intervals. The
openings vary greatly in size, depending upon the size of the duct,
the length of the run or the size of the room being serviced. Of
course, other engineering design requirements affect the selection
of the opening size. Consequently, frames must be available to
reinforce the duct opening and to be mounted on the duct opening to
receive grilles, registers and access doors. In the past, frames
have been constructed at a factory or shop and shipped to a job
site. A multitude of frames sizes must be manufactured and must be
available at the job site. Prefabricated frames are expensive in
that a wide variety of sizes must be made and stored by the
manufacturer or contractor. Further, the prefabricated frame is
difficult and time consuming to attach to an opening in the
Fiberglas duct. Therefore, the contractor, the manufacturer or the
contractor's supplier must maintain a large inventory of duct
frames which have been prefabricated so that the contractor may
meet the varying engineering requirements for the heating,
ventilating and air conditioning duct systems.
With these comments in mind, it is to the elimination of these and
other disadvantages to which the present invention is directed,
along with the inclusion therein of other novel and desirable
features.
An object of my invention is to provide a new and improved duct
opening frame for attachment to Fiberglas ducts to provide means to
assemble grilles, registers and access doors to the Fiberglas
ducts, which duct opening frame is of simple and inexpensive
construction and operation.
Another object of my invention is to provide a new and improved
duct opening frame which may be supplied in coil form and formed to
fit a predetermined opening at the job site with conventional tools
and by hand.
Still another object of my invention is the provision of a duct
opening frame which is shipped and stored in coil form thereby
taking a minimum of storage or shipping volume yet which is
manufactured from flexible, bendable sheet material which is easily
fabricated on the job by conventional tools and by hand; and which
sheet material includes slots along the bending lines to decrease
bending resistance thereby allowing the operator to more
conveniently bend the duct opening frame to snugly fit the
Fiberglas duct without undue difficulty in performing the bends by
hand.
A further object of my invention is the provision of a duct opening
frame for attachment to Fiberglas ducts to provide means to receive
grilles, registers and access doors directly thereon, which duct
opening frame is extremely simple in its assembly and operation and
will thereby permit quick and easy fabrication and attachment to
Fiberglas ducts by a person of minimum skill and manual
dexterity.
These and other objects and advantages of my invention will more
fully appear from the following description made in connection with
the accompanying drawings wherein like reference characters refer
to the same or similar parts throughout the several views, and in
which:
FIG. 1 is a diagrammatic view of my duct opening frame as it
appears in operation attached to a Fiberglas duct, with a grille
mounted thereon and with portions of the components broken away for
clarity;
FIG. 2 is a perspective view of my duct opening frame in coil form,
shown prior to assembly;
FIG. 3 is a perspective view showing an initial step in the
fabrication of my duct opening frame prior to assembly of the duct
opening frame to a Fiberglas duct;
FIG. 4 is a perspective view of my duct opening frame as it would
appear just prior to assembly to a Fiberglas duct;
FIG. 5 is a plan view of the novel press clip;
FIG. 6 is a perspective view of the novel press clip shown
partially bent and prior to assembly to a Fiberglas duct;
FIG. 7 is a perspective view showing the alternate embodiment of my
invention assembled to a Fiberglas duct showing a grille mounted
thereon and with portions broken away for clarity; and
FIG. 8 is a perspective view of another embodiment of my invention
shown in coil form.
In FIG. 1, a Fiberglas duct 10 is shown with a duct opening frame,
indicated in general by numeral 11 mounted thereon. The duct
opening frame is shown completely assembled with a grille 12
attached thereto by screws 13. The longitudinal duct opening is
indicated by numeral 14 and the assembled duct opening frame 11
conforms to the opening in the duct in length and depth.
Referring now to FIG. 2, frame 11 is shown in roll or coil form,
indicated by numeral 15. The roll comprises a plurality of duct
engaging tabs 16 which are bendable along foldline or bendline 17.
Longitudinal slots 18 are provided at predetermined intervals along
foldline 17 to decrease the bending resistance of tabs 16 as they
are bent or folded. The tabs are connected to web or collar 19. A
grille or diffuser receiving element 20 is foldably attached to web
19 along foldline or bendline 21. Longitudinal slots 22 are
provided along foldline 21 at predetermined intervals to decrease
the bending resistance of receiving element 20 on web 19. Receiving
element 20 includes a plurality of slotted apertures 23, transverse
to foldlines 17 and 21 and spaced longitudinally along receiving
element 20. Each receiving element actually constitutes an
outturned flange.
Tab 16 may be provided with inwardly crimped terminal portions 24
crimped along foldline 25. These terminal portions may be omitted
if desired.
Frame 11 is formed from the coil 15 by first notching receiving
element 20 at predetermined intervals longitudinally along the
receiving element as it is dispensed from coil 15. The notch is cut
with conventional tools inwardly to foldline 21, and is indicated
in FIG. 3 by numeral 26. Similarly, if necessary, a corresponding
notch may be made in tabs 16 cut inwardly to foldline 17. (This
notch is not shown herein). Notches 26 are cut in the receiving
element at intervals corresponding to the length and depth of
opening 14 in duct 10. The web is then bent at 90.degree. along
foldlines 27 to form frame 11. The web may be welded together, if
desired. In this configuration, an upper lengthwise receiving
element 20a and a corresponding lower lengthwise receiving element
20b is provided. Further, a pair of opposed receiving side elements
20c and 20d are provided. In like manner a plurality of upper
lengthwise tabs 16a and corresponding lower lengthwise tabs 16b are
provided. A pair of opposed side tabs 16c and tabs 16d are also
provided. It should be noted that the inwardly crimped portions 24
of the tabs provides ease in inserting the rectangular frame 11
into duct opening 14.
Prior to insertion of the duct opening frame into the duct opening,
the respective receiving elements 20a, 20b, 20c and 20d are folded
outwardly at right angles to web 19. The frame, with tabs 16a, 16b,
16c and 16d projecting outwardly from the respective webs, may then
be inserted into opening 14, as shown in FIG. 4. The outwardly
projecting receiving elements abut duct 10 preventing further entry
of the frame 11 into opening 14. At this point, web portions 19a,
19b, 19c and 19d, confront the portions of duct 10 which define
opening 14 and are snugly abutted thereagainst. Duct engaging tabs
16a, 16b, 16c and 16d are folded into duct engaging relation by
hand, sandwiching duct 10 between the tabs and the receiving
elements thereby tightly securing frame 11 to duct 10 at opening
14. (See FIG. 1)
The duct opening frame is fabricated from 24 gauge galvanized sheet
metal and is die cut to provide the tabs and receiving element
therein. Slots 23 and 32 are one-eighth inch wide to receive a No.
8 sheet metal screw for mounting of grilles, registers, diffusers
and the like thereto.
An alternate form of my invention is shown in FIG. 5. A press clip
is indicated, in general by numeral 28 and includes a pair of duct
engaging tabs or points 29 at each end thereof. A pair of webs 30
are connected to tabs 29. Receiving element 31 is connected to webs
30 therebetween and includes slotted apertures 32. Tabs 29 are
bendable along foldlines 33 which include slots 34 therealong to
decrease the bending resistance of tabs 29 relative to webs 30.
Webs 30 are foldable relative to receiving element 31 along
foldlines 35 which include slots 36 therealong to decrease the
bending resistance. Press clip 28 is formed from 24 gauge
galvanized sheet metal. Typically, the press clip is utilized to
form a duct opening frame for ducts requiring mounting of a grille,
diffuser, register and the like at transverse openings thereof.
In some instances, the press clips 28 will be utilized to mount and
form a duct opening frame in one of the longitudinal walls of a
duct rather than at the end of the duct as shown in FIG. 7. For
example, it may be desirable to use the press clips 28 in the
formation of a duct forming frame in the manner illustrated in FIG.
1. When the press clips are used in this fashion, the slots 32 in
the press clip through which the screws pass will not be formed in
the receiving element 31 but will be received in one of the webs
30. Specifically, the slots 32 will be formed in that web 30 which
is presented outwardly. It is also pointed out that when the press
clips are used to mount and form a frame such as the duct opening
frame illustrated in FIG. 1, one of the web portions will
preferably be longer than the other web portion.
A duct 10' is shown in FIG. 7 having transverse opening 14'. Press
clips 28 are spaced along each side of the opening providing four
clips denoted by numerals 28a, 28b, 28c and 28d. A grille 12' is
shown mounted thereon with four screws 13' securing grille 12' to
press clips 28 which are, in turn, securely mounted on duct
10'.
Another alternate form of my invention is shown in FIG. 8 which
shows coil 15' having receiving element 20' with a plurality of
circular openings 37. The openings are one-eighth inch in diameter
to receive No. 8 sheet metal screws. Of course, press clip 28 may
include circular openings rather than slotted openings 32 if
desired. Coil 15' includes web 19' and tabs 16' bendably attached
thereto.
In operation, the duct opening frame of my invention, when utilized
to provide a frame for a longitudinal opening on a Fiberglas duct,
is formed from coil 15. The frame size required is determined and a
sufficient amount of material, corresponding to the perimeter of
opening 14 in duct 10, is uncoiled and cut from the coil. The
amount of material which is cut from the coil includes an extra
half inch for overlapping. Next, conventional tinsnips are used to
cut into the receiving element substantially normal to elongate web
member 19, at intervals corresponding to the width and depth
dimensions of duct opening 14 with notch 26 proceeding inwardly to
foldline 21. If necessary, duct engaging tabs 16 may be similarly
cut transverse to elongate web member 19, to foldline 17, if
necessary.
The material may now be folded transversely at the web member along
foldlines 27 to form a rectangular frame. As shown in FIG. 3, the
frame is partially formed and is ready to be inserted into opening
14. First, receiving elements 20 are folded outwardly along
foldlines 21 which are slotted at 22 to decrease the bending
resistance. Frame 11 may now be inserted into opening 14 and is
pushed into the opening until receiving elements 20 abut duct 10.
The installer may now bend tabs 16 outwardly along foldline 17
sandwiching the duct between the receiving element and the duct
engaging tabs.
The duct is now properly prepared to receive a register, diffuser,
grille or access door. The unit may be attached directly to frame
11, utilizing slotted openings 23 in the receiving element. The
slotted openings are one-eighth inch wide to receive a standard,
No. 8 sheet metal screw.
In some instances, it is desirable to place a grille, diffuser,
access door or register on a transverse, either circular or
rectangular, opening in a duct system. This may be done by
utilizing press clip 28 which is folded along foldlines 33 to
provide duct engaging tabs 29 to engage duct 10', and then folded
along foldlines 35 such that the edge of the duct 14' receives the
receiving element 31 so that a unit may be secured thereon.
From the foregoing it will be seen that I have provided a new and
novel duct opening frame for use with Fiberglas duct systems which
is not only simple and efficient in construction and operation, but
which is capable of being formed to fit varying size openings in
ducts as may be necessary under design requirements. Further, the
duct opening frame of my invention is provided with slots along
foldlines to decrease the bending resistance such that all folds
may be made by hand without the need for any tools whatsoever.
This, therefore, greatly speeds up the assembly of my duct opening
frame to Fiberglas ducts and results in considerable savings in
labor costs to the contractor.
It will, of course, be understood that various changes may be made
in the form, details, arrangement and proportions without departing
from the scope of my invention.
* * * * *