Note: Descriptions are shown in the official language in which they were submitted.
1066'738
This invention relates to expansion ~oints and ln
particular to expansible couplings ~or ducts such as in alr
quality control systems wherein boller exhaust gases are
directed through sophisticated scrubber~ prior to exhausting
the same through a stack and into the atmosphere.
In duct work systems there is a need to compensate
~or the thermal expansion and contraction o~ the duct material,
as well as the axial misalignment o~ the various duct sectlons.
Expansible couplings, having a Plexible, ~luld impermeable
material, are there~ore dispersed appropriately throughout the
duct system. For very large ~lze duct work, such as that
used in air quality control systems ~or power plants, the
ducts o~ten have a peripheral dimension ln the nature o~ 50
reet and more. In such system~ it is not only dlr~lcult to
securely seal ~uch a large openlng, but inasmuch as the ~lexi-
ble material must be periodically replaced, the expan~ible ~
couplings need to be capable o~ easy disassembly to minimize -~-
the system's down time and to reduce malntenance cost~.
The principal ob~ect~ o~ the present inventlon are:
20 to provide an expansible coupling having mating seating sur- ;~
faces such as V-shaped cooperating member3, which securely and
po~itively seal the various duct segments; to provide such a
¢oupling wherein the cooperating V-shaped members are urged
together by a plurality o~ fastening devices having pivotally
mounted arms ~or the quick and easy replacement o~ the flexible -~
seal; to provide such a coupling whereln each fastening device
is slidably attached to the duct by a channel-shaped way ~or
lmproved maintenance e~ficiency and seal integrity; to provide
such a coupling wherein the V-shaped clamping members are posi-
tioned along a terminal end edge of each duct whereby the ~lex-
lble seal member, in a relaxed stateJ assume~ a substantially
parabollc or catenary con~lguration ~or improved ~atigue
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resistance and durability; and to provide such a coupling
which is economical to manufacture, e~ficient in u~e, capable
of a long operating li~e, and particularly well adapted for
the proposed use.
According to the invention there is provided an
expansible coupling ~or sealingly Joinin~ ~irst and ~econd
ducts at ad~acent end~ thereo~, sald coupling comprising:
(a) rirst and second elongate rim members adapted ror attach-
ment to said ~irst and second ducts re~pectively ad~acent the
10 - ends thereof, and having an outer surface o~ a V-shaped conflg-
uration; (b) ~irst and second elongate segmented clamping
members, each of ~aid clamping members havlng an inner sur~ace
of V-shape and cooperatively mating with the outer sur~ace o~
said ~irst and second rim members respectlvely, said outer sur-
faces of said ~irst and second rim members being disposed lon~
tudlnally therein with the sides o~ the V-shapes ad~acent the
duct end having correspondlng slope relative to the respective
duct end; (c) a flexible seal member extending around the ductæ
at the ad~acent ends thereof and having opposing marginal side .- :-
edge portions overlapping said duct end~ and respectively
clamped between the outer and inner surfaces o~ said ~irst and .
second rim and clamping members; (d) means urging said rim and
clamping members together to sealingly clamp said seal member
side ed8e portlons; and (e) said ~lexible seal member initially :
being an elongate transver~ely flat strlp with end portions
thereo~ ~oined and forming a belt de~ormed b~ the respective .
first and second rim and clamping members at marginal side por-
tions with a portion therebetween extending there~rom at angles
corresponding to the slope o~ the sides o~ the V-shapes ad~acent
the end8 o~ the ducts and connected by a transversely arcuate
central portion
Other ob~ects and advantages o~ this lnvention will
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become apparent from the following description taken in connec-
tlon with the accompanying drawing~, wherein are set forth, by
way o~ illustration and example, certain embodiments o~ thls
invention.
The drawings constitute a part o~ the ~pecl~ication
and include exemplary embodlments of the present lnventlon and
lllustrate varlous obJects and features thereof.
Fig. 1 ls a diagrammatic illustration of an exhaust
gas scrubblng system employlng expan~ible couplings embodying
the present lnventlon.
Fig. 2 is a ~ragmentary perspectlve view o~ an expan- -
~ible coupllng attached to adJacent duct segments.
Flg. 3 is a ~ragmentary, vertlcal cro~s-3ectional
view o~ the ~lexible coupling and adJacent duct segments in an
expanded state, and wherein phantom lines indicate a relaxed
state.
Referring more in detail to the drawings:
As required, detailed embodiments o~ khe pre~ent
invention are disclosed herein, however, it is to be understood
that the disclosed embodiments are merely exemplary of the
. .
invention which may be embodied in variou~ forms. Therefore,
~peci~ic structural and ~unctional details disclosed herein are
not to be interpreted as limiting, but merely as a basis for the
claims and as a representative basis for teaching one skilled in
the art to variously employ the pre3ent invention in virtually
any appropriately detailed structure.
The reference numeral 1 generally deslgnate3 an expan-
~ible coupling for Joining the ends o~ adJacent duct work seg-
ment~ 2. The coupling 1 comprises a rim 3 having a protruding ~-
~urface, such a~ an inverted V-shape, attached to and exkending
around each duct adJacent the open end 4 thereof, and a pair of
elongate, segmented clamping member~ 5 having a longitudlnal
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channel 6 therein which cooperatively mates with the rim 3, A
flexible, non-metallic seal member 7 has marginal edge portion~
8 thereof retained between the rim 3 and clamping members 5, and
a plurality of ad~ustable fasteners 9 are positioned regularly
about each duct end 4 and urge the rim and clamping members
to~ether to ~orm an airtight and flexlble Joint. -
The illustrated expanslble coupling 1 is particularly
adapted ~or use in air quality control systems ~or power plants
~uch a3 that diagrammatically illustrated in Fig. 1 and gener-
ally designated by the reference numeral 1~. The boiler 14,wherein water is heated lnto steam, directs the exhaust gases
Or combustion therefrom into a duct work ~ystem 15 comprised o~
a plurality o~ interconnected duct ~egments, and conveys the
gases to a scrubber 16 wherein particles and noxious gases are
removed there~rom. The clean gases are then directed through a
second duct work system 17 to a stack 18 and expelled therefrom
into the atmosphere. Each of the duct work systems 15 and 17
include intermittently dlspersed expansible coupllngs 1 to
accommodate ~or the expansion and contractlon of the duct work
as the material therein reacts to temperature changes induced by
various plant operating condition~.
The duct segments 2 are elongate, tube-like structures
~or conveying M uids such as exhaust gases therethrough, and are
conventionally constructed of a metallic material~ such as sheet
steel. The ducts have a lateral, cross-sectional shape which,
at lea~t at the end portions 4 thereo~, is pre~erably ~ree o~ -
sharp corners, such as circular, oval, and the like, In the
illustrated structure, khe duct segments 2 have a reckangular
~hape with the corners 22 thereo~ rounded on a radius in the
nature o~ 10 lnches.
The rim 3 is an elongate structure having an lnverted
V-shaped outer surface and is ~astened to and pro~ecting from
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each duct end 4. In the illustrated example, a substantially
rlat band member 25 is ~astened about the duct end 4 by mean~ -
such as welding or the like, to ~acilitate coupling manufacture,
and the rim 3 is in turn attached to the upper sur~ace of the
band 25. The rim 3 is illustrated a~ belng constructed Or
angle material such as steel or iron, and having a shape sub-
stantially similar to an isosceles right triangle whereln an
inner base edge 26 thereof is positioned coextensively with the
terminal end edges 27 and 28 respectively of the band 25 and
duot 2. The uppermost edge 29 o~ the rim 3 ls prererably
slightly rounded to avoid cutting the flexible seal member 7,
and the inclined sur~aces 30 thereo~ are preferably smooth.
Each o~ the elongate clamplng members 5 have a V-
shaped channel 6 disposed longltudlnally thereln which coopera-
tlvely mates with one o~ the proJecting rims 3. In this ex-
ample, the clamping member 5 is divided into ~eparate ~traight
and curved segments 34 and 35 respectively, which are positioned
in an end-to-end fashlon. In this manner, the clamping member 5
need not be distorted or bent to disengage the same from its
associated rim member 3. Further, the segmented clamping member
deslgn facilitates the manu~acture of the coupling, and reduces
rlexible seal replacement time. m e interior sur~aces 36 o~
each clamplng member 5 mate with the lnclined rim ~ur~aces 30
and are prererably smooth. In the lllustrated structure, the
clamping members are constructed of a V-shaped angle materlal - -
for reduced cost and weight, and for improved rigidity and ~
strength. --
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The ~lexlble seal member 7 is of the ~lat belt, boot ~ ~
type whlch is typically constructed o~ a single piece of ~lex- ~- -
ible, heat re81stant, ~luid impermeable material such as a
rubber-asbestos compound. ~he end~ o~ the seal member 7 are
molded together to form a boot with a longitud~nally extending
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seam 37. In the illustrated structure, the ~eal member 7 i~ of
a two-ply constructlon ~or improved durability. Further, the
seal member 7 is without a preformed shape, whereby upon ln~tal-
lation in the expanslble coupling, it assumes a free-hanging,
parabolic or catenary con~iguration in its relaxed state, which
ls particularly resistant to fatigue deterioration.
Each of the ~asteners 9 include~ a bar portion 40
having a ~irst or forward end 41 thereof abutting an upper,
central edge 42 o~ the clamplng member 5. The second or rear
end 43 o~ the bar 40 ha~ a leg portion 44 attached to and de-
pendlng there~rom ~or engaging a ~tationary portion o~ the duct
2. The bar 40 also includes a transver~e aperture 45 there-
through di~po~ed between the bar ends 41 and 43 respectively. A -
~a~tening device 46 i~ positioned through the aperture 45 and
ha~ a lower end 47 connected with the duct 2 and an upper end 48
engaging the bar 40 and pulling downwardly thereon. In this
example, a channel-shaped way 49 ia connected wlth each band 25
at a point rearwardly o~ the rlm 3. Each way 49 comprlses a
base 50, and oppo~ed and upstandlng side wall~ 51 having inwardly
20 extending Man~es 52 thereon. ~he lower end 47 o~ the fastenlng
device includes a head 53 having f`lat opposing face~ 54 which
~lidingly engage the way ~ide walls 51 thereby preventing rela-
tive rotation between the way 49 and the fastening device 46.
The flangea 52 of the way engage an upper sur~ace o~ the bolt
head 53 thereby ~lidlngly mountlng the same wlthln the way ~uch
that each ~astener can be ea~ily posltioned about the periphery
o~ the coupling. In this example, the upper end 48 of the
faatenlng device i~ threaded, and a nut 55 i~ engaged therewith
for ad~ustably tightening the rim and clamping member~ 5 and 3
3o respectlvely. Further, the leg 44 o~ the bar 40 i~ posltioned
abuttlngly upon the outwardly most 31de wall 51 o~ the way ~uch
that when the nut 55 i~ loosened the bar can be ea~ily pivoted
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~ 066738
and disengaged ~rom the clamplng member 5.
In use, a worn ~lexible ~eal 7 can be easlly and
economlcally replaced. The u3er ~lr~t loo~en~ fa~tener nut 55
and then, without removlng the ~ame ~rom the bolt 46, plvot~ the
bar 40 such that the clamping member 3 ls ~ree from the lnner
end 40. Each of the clamplng member segments 18 then detached
~rom the rlexlble seal 7, whlch 1~ then ln turn removed from the
rim 3. The new seal 1~ placed on the rlms 3, and the clamping
member~ are posltloned thereover and clamped lnto place by posl-
tioning and then tightenlng each fa~tener 10.
In ~tructure~ having ~luid moving therethrough under
pressure, it is desirable to have the seal member 7 flex out-
wardly. In such installations, the rim members 3 are inverted
to present an outwardly ~acing channel and the seal 7 ha~ a
portion resting therein. The clamp member is also reversed 80
that the inner ~ur~ace thereo~ mate~ with the channel~ o~ the
rim members and clamp the seal member therebetween.
It is to be under~tood that while I have illu~trated ~ -
and described certain ~orm~ o~ my invention, it i~ not to be
limited to the ~peci~ic ~orms or arrangement o~ parts herein
de~cribed and shown.
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