CA1089696A - Rotating blade fire damper - Google Patents
Rotating blade fire damperInfo
- Publication number
- CA1089696A CA1089696A CA333,584A CA333584A CA1089696A CA 1089696 A CA1089696 A CA 1089696A CA 333584 A CA333584 A CA 333584A CA 1089696 A CA1089696 A CA 1089696A
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- Canada
- Prior art keywords
- blades
- blade
- closed position
- frame
- damper
- Prior art date
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Abstract
ROTATING BLADE FIRE DAMPER
Abstract of the Disclosure A novel fire, smoke and air control damper is disclosed wherein one or more hook-shaped hinge portions formed intermediate between the longitudinal edges of each damper blade engage complementally configured hook-shaped hinge elements formed on opposite sides of the damper frame.
Formed on each of the ends of each damper blade are additional hook-shaped sealing portions which are adapted to mate with the hook-shaped sealing portions of adjacent blades in the closed position in order to form a double seal. A "dead" air chamber is formed between contiguous portions of adjacent blades when those blades are in the closed position. As the blades are slightly displaced towards the open position, a seal is none-the less maintained between the blades due to the configuration of the sealing portions thereof. As the blades are further displaced, a serpentine air path is formed having a maximum fluid frictional resistance, which resistance is further amplified by the provision of a spoiler disposed adjacent to the tip of each hook-shaped sealing portion of each blade.
Finally, the blades are movable to any of a variety of open positions so that volume control is easily effectuated.
In the closed position, various blade portions also engage opposite sides of an inwardly depending flange in said frame to form a seal therebetween, thereby providing a positive pressure resistant seal.
Abstract of the Disclosure A novel fire, smoke and air control damper is disclosed wherein one or more hook-shaped hinge portions formed intermediate between the longitudinal edges of each damper blade engage complementally configured hook-shaped hinge elements formed on opposite sides of the damper frame.
Formed on each of the ends of each damper blade are additional hook-shaped sealing portions which are adapted to mate with the hook-shaped sealing portions of adjacent blades in the closed position in order to form a double seal. A "dead" air chamber is formed between contiguous portions of adjacent blades when those blades are in the closed position. As the blades are slightly displaced towards the open position, a seal is none-the less maintained between the blades due to the configuration of the sealing portions thereof. As the blades are further displaced, a serpentine air path is formed having a maximum fluid frictional resistance, which resistance is further amplified by the provision of a spoiler disposed adjacent to the tip of each hook-shaped sealing portion of each blade.
Finally, the blades are movable to any of a variety of open positions so that volume control is easily effectuated.
In the closed position, various blade portions also engage opposite sides of an inwardly depending flange in said frame to form a seal therebetween, thereby providing a positive pressure resistant seal.
Description
~89~6 This application is a division of application Serial No. 272,088 Eiled February 18, 1977.
Background of the Invention The present invention relates generally to the field of air control dampers, and more particularly, to those air control dampers which are intended to regulate the volume of air passed along a duct or plenum, or through an opening, and which damper is further adapted to prevent the passage of smoke or fire therethrough when the damper is in a closed position.
In particular, a suitable fire, smoke and air control damper should be easily operable to allow the flow of air therethrough at any of a desired number of pre-determined settings between the closed and open positions of the blades with respect to the frame. With respect to the fire and smoke control aspect of such a damper, it is also important that a damper be capabie of withstanding intense heat and/or air pressures which impinge on either ` side of the damper for substantial periods of time during a fire. Due to the extreme conditions to which such a damper is subjected, it is necessary to provide extremely strong blades and a very substantial frame which, toqether, form a tight, positive seal to effectively shut off the air duct, opening, or plenum. In Eact, due to the ~-deficiencies experienced by some practitioners in this field, folding blade fire dampers have been utilized in order to overcome those deficiencies otherwise encountered by some devices utilizing a plurality of rotating blades, ` each of which blades must form a seal with an adjacent blade as well as the frame, which seal is sometimes prone to leakage in the event that extremely precise alignments and tolerances are not maintained. This problem has been ''.,: .
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accentuated by the fact that a smoke and fire damper mus-t function effectively years after it is installed in a relatively dirty environment.
Prior art rotating blade fire and smoke dampers have therefore incorporated extremely heavy materials which are not subject to easy bending or deformation in the presence of heat. The blades are mounted by distinct hinge or pivot means which are separately installed for the purpose of aligning each of the blades for rotational movement and to ensure the interengagement of each blade with its adjacent blade to form a seal therebetween which does not open in the presençe of heat or excessive pressures, such as those which might be encountered during a fire.
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Summary of the Invention The present invention overcomes many of the disadvantages of prior art fire, smoke and air control dampers by providing -in an air control damper comprising a frame, a plurality of blades and rotation means for allowing selective rotational displacement of each of said blades between an open and closed position with respect to said frame, the improvement wherein contiguous portions of adjacent blades are configured to form a seal therebetween when said blades are in the closed position, and to substantially maintain said seal through a predetermined arc of blade rotation as said blades ~-~
are moved from the closed position towards the open position, ~`
the longitudinal edges of adjacent blades being configured to form opposing hook shaped portions, the tip of each hook shaped portion being configured to engage an interior surface of the hook shaped portion of its adjacent blade in the closed position.
Unlike prior art fire dampers, the present invention is readily constructed from relatively light sheet metal materials.
Embodiments of the invention are illustrated in the accompanying drawings. ~;
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Brief Description of the Drawings Figure 1 is a top view of the preferred embodiment of the present invention disposed adjacent to an air flow opening shown in phantom, which opening is broken away;
E`igure 2 is a front view of the preferred embodiment of ;:~
the present invention;
Figure 3 is a back view of the preferred embodiment of ~ -the present invention as shown in Figure 1, taken as indicated ; by the lines and arrows 3-3 in Figure l;
Figure 4 is a greatly enlarged cross-section of a : ~ -portion of the preferred embodiment of the present invention illu-strated in Figure 2, taken as indicated by the lines and arrows 4-4 in Figure 2, and further wherein the open position of the blades with respect to the frame is shown in phantom;
~igure 5 is an enlarged cut~away back view of the preferred .
embodiment of the present invention as illustrated in Figure 4, : taken as indicated by the lines and arrows 5-51in Figure 4; ::
Figure 6 is an enlarged cross-sectional top view of a .
portion of the preferred embodiment as illustrated in Figure 4, taken as indicated by the lines and arrows 6-6 in Figure 4;
Figure 7 is a greatly enlarged perspective view of a portion of the preferred embodiment of the present invention wherein a portion of the frame has been cut away to show the hinge detail. ; :
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96g6 Detailed Description of the Drawings Referring now to all the figures, and in particular, to Figure 1, the damper of the present invention in its pre-ferred embodiment is a generally box-shaped damper for disposi-tion in an opening which in Figure 1 is diagrammatically illu-strated by wall sections 10 and 12. The damper, designed generally 14 in the drawings, comprises a frame designated generally 16 and a plurality of blades 18, 22, 26, and 30. The frame designated ; generally 16 comprises inwardly depending flanges 34 and 36 which are disposed on opposite sides-of the frame 16 in a plane which is substantially parallel to the plane of the blades 18, 22, 26, ~ -and 30 in the closed position. Additional inwardly depending flànges 38 and 40 are also formed in this plane at the top and , ` bottom of the frame. The first of tbe aforementioned inwardly depending flanges 34 and 36 (the side flanges) are adapted to form a seal with the ends of blades, while the last of the aforementioned in-wardly depending flanges 38 and 40 form seals with top and bottom ., blades 18 and 30 when those blades are in the closed position.
In constructing frame 16 the appropriate portions of the inwardly 20 depending flanges 34, 36, 38, and 40 are notched so that when folded into the aforementioned plane, a seal if formed at inter-.
sections 42 by welding, crimping or some other similar suitablemethod. The frame designated generally 16 further comprises a top 4~, a bottom, and sides 46 and 48 which extend generally per-pendicularly to inwardly depending flanges 34 and 36 respectively.
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. ,, ' ' ' ~ ': ',, The construction and assembly of the frame is generally similar to that described in my previously issued U.S. Patent No. 3,833,989 entitled "Method of Fabricating and Assembling a Damper."
Referring now to Figure 3 which is a back view of the preferred embodiment of the present invention, additional inwardly depending top and bottom back flanges 50 and 52 are illustrated to-gether with inwardly depending back-side flanges 54 and 56. For clarity, a major portion of back-side flange 56 has been cut away in order to clearly illustrate the means for articulating each of the blades with respect to each other and with respect to the frame. These back flanges are generally parallel to the aforemen- -tioned inwardly depending flanges 34, 36, 38, and 40 and provide means for mounting the damper on a wall such as illustrated in Figure 1 by using screw slots 58. The means for simultaneously articulating or rotating each of the blades 18, 22, 26, and 30 with respect to each other and with respect to the frame is clearly illustrated. This means is preferably disposed against an interior `
; surface of side wall 48 of the frame, said means generally com~
prising blade engaging brackets 19, 23, 27, and 31, which brackets are pinned for rotational movement with respect to rod 60. Rod 60 ` in turn is appropriately movable along an axis parallel to the axis . ~ .
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each of the blades to assume a preselected orientation with respect to the frame7 Referring now to Figure 4~ which is a cross~section of a portion of the preferred embodiment sho~n in Figure 2, the relative positions of the blades are shown in two different positions. Blade 22 and a portion of blades 18 and 26 are shown disposed in the closed position with respect to inwardly depending ~;~
flange 36. In a phantom view, blades 22 and 26 are rotated to .. . .
the open position, which opening is accomplished by movement of 10 rod 60 along the axis as indicated by arrow D in Figure 4 to the ;
phantom position.
Referring now specifically to the particular blade con-figuration utilized in the preferred embodiment of the present invention, the blade designated generally 22 has disposed inter- ~
mediate between the two longitudinal edges thereof a hinge portion - ;
designated generally ~2. This hinge portion may be roll formed in the blade extending longitudinally across its length. Hinge portion 62 generally comprises hinge tip 64, rounded portion 66, blade offset 68 and overlapping portion 70. My previously issued patent, U.S. Patent No. 3,908,529, disclosed a backdraft damper with a particuIar blade frame hinging interaction.
As seen in Figure 4, each blade, such as blade 22, -is defined by the hinge portion designated generally 62 into two distinct sections: a first outer blade section 22a disposed between the hinge portion designated generally 62 and first blade ;
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tip 70; and a second inner blade section 22b which is disposed generally between the hinge portion designated generally 62 and second blade~tip 72~ As: clearly illustrated in Figure 4, the inner blade section 22b and the outer blade section 22a are parallel and sli~htly spaced apart, which spacing is generally :
established by the configuration of hinge portion 62 and in parti-cular by the length of blade off-set 68~ In the preferred embodi-ment as shown in Figure 4, the outer blade section 22a and inner blade section 22b are spaced apart by a dis~tance which is sub-stantially equal to the thickness of the inwardly depending flange ; designated generally 36 in Figure 4, Inwardly depending flange 36 is formed into a hook-shaped hinge element designated generally 80, which hinge element is formed by notching the appropriate ,., portions of inwardly depending flanges 34 and 36 on opposite sides so that each of the hinge elements such as hook-shaped hinge ele-ment 80 are disposed on opposite sides of the frame for engagement in articula-ted rotational relationship with hinge portion 62 of each respective blade.
By so constructing each of the blades in a rotating blade fire damper so that a hinge portion is, as shown in Figure 4, generally ~ormed intermediate between che tips of the blade, and then by correspondingly off~setting each of two sections of that blade by the width of the associated : inwardly depending flanges of that blade, it is possible .: ,:
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., ' 9~;96 to form an effective seal alon~ the ends of each of said blades which are contiguous to said inwardly depending flanges. As shown in Figure 4, inner blade section 22b is firmly pressed up against the inner surface of inwardly depending flange 36. Following the blade downwards along flange 36, overlapping portion ~0 of the hinge portion designated generally 62 is seen to form a seal between it and the interior surface of the base of the hook-shaped hinge element designa-ted generally 80 formed in the flange.
~herefore, the inner blade section and the overlapping portion of the hinge portion 62 form a seal with the inner -surface of inwardly depending flange 36, while the blade off-set 68 extends outwardly beyond the outer surface of - ~ - ~-inwardly depending flange 36 so that the outer blade section 22a will, when the blade is in the closed position, form a seal between the blade and an outer surface of inwardly depending flange 36.
Another f~eature of the present invention is in ; the unique sealing arrangement which is effected between adjacent blades along the portions of those blades adjacent to their longitudinal edges. Each longitudinal edge portion of said blade designated generally 90 for blade 22 is formed into a hook-shaped configuration. Each of the `~ hook-shaped configurations formed on these longitudinal . .
i edge portions open towards the inwardly depending flange .! 36. For example, a fir$t upper longitudinal edge portion ` 90 opens towards the inwardly depending flange 36.
` Similarly, the other longitudinal edge portion designated generally 90 opens in the opposite direction from the first longitudinal edge portion 90, but nonetheless towards : ' ,'; '::
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9~96 inwardly depending flange 36 due -to the disposition of - outer blade section 22a on the opposite side of inwardly ` depending flange 36. Each of the longitudinal end portions of a particular blade are formed into a plurality of portions which portions act to form a chamber or chambers 92 which are "dead air" chambers formed between the longitudinal edge portions of adjacent blades when those blades are in the closed position. Therefore, offsetting portion 94, extension portion 96, transverse portion 98 and tip 100 are formed to coact with the analogous portions on an adjacent blade in the closed.position to form the aforementioned chamber 92. In particular, the function of offsetting portion 94 is to move the interior surface of extension portion 96 away from the plane of the contiguous section of the blade so that upon the slight misalignment and/or slight opening of the blades, the leading edge of the blade (i.e., the edge formed at the intersection of the transverse portion 98 and the tip 100) will move in an arc substantially -parallel to the surface of the offsetting portion 94 so that a seal will be substantially maintained through an arc of the leading edge having a length of approximately bne-half of the length of the offsetting portion. In . :-alternate embodlments, the of~setting portion may be curved or otherwise shaped to more closely approximate the arc of the leading , ' ' ~ "
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6~6 edge to thereby maximize the wiping action thereof. The length of the offsetting portion may similarly be varied depending upon the desired arc of blade rotation while maintaining the double seal between the blades. A serpentine air path will also be formed as the blades open slightly beyond said arc or in the event of leakage between the leading edge and the offsetting portions, which poses maximum resistance to air impinging on either side of the fire damper. As previously mentioned, a double seal is also formed between the tips lOQ of adjacent blades and the interior surface of the extension portions 96 of adjacent blades, each of which is parallel to but spaced apart from the plane of their adjacent blade sections when the blades are in the fully closed position.
Transverse portions 98 of adjacent blades are substantially ; parallel to each other when said blades are in the closed postion, thereby imparting, together with the aforementioned portions, a cross-sectional configuration to chamber g2 which is a parallelogram having its shorter parallel sides formed : .
by tipfi lOQ and extension portions 96 and longer sides formed by transverse portions 98. Spoilers 102 are additionally disposed on each of the tips lOQ which act to increase the turbulence of the air which would tend to pass through the chamber 92 in the aforementioned serpentine fashion as the blades are moved as aforesaid. Thus, a double seal will exist as long as the tip lOQ of one blade is disposed coplanar with or on the opposite side of the plane defined by the con~
tiguous section of the adjacent blade. ;
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Referring now to the means for articulating the blades with respect to each other and with respect to the frame, blade engaging brackets 23 and 27 are illustrated in Figure ~, and are seen to comprise base portions 200 and 202 which are offset to firmly engage the respective blade sections and are r~veted thereto. Extending generally away in a tri-angular manner from base portions 200 and 202 towards a ful-crum point 203 at which a pivot 206 is disposed, these blades engaging brackets are connected pivotally with rod 60 so that upon movement of any one of the aforementioned blades or of the rod 60 along the axis as indicated by arrow B in Figure 4, each of the blades moves to a position such as the position shown in phantom in Figure 4 which has been referred to herein as "the open position" of the blades with respect to the frame.
In this position, the relative proportions of the hook-shaped .
portions formed on the longitudinal edge portions 90 of each of the blades is seen to be relatively minor with respect to the width of the blades, thereby permitting air to freely pass through the damper when the damper is in the open position. Disposed between base portions 200 and 202 of each of the blade engaging brackets is in arcuate cut-out 204 which allows clearance for the aforementioned hinge portion designated generally 62 of èach of the respective associated blades.
Referring now to Figure 5 which is an enlarged :'. ':, " '`, : ' -13~
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9~i~6 cut-away back view of one of the blade enga~ing brackets, namely blade engaging ~racket desi~nated generally 23, it will be seen that rod 60 is disposed substantially adjacent to side wall 48. The placement of rod 60 substantially adjacent to side wall 48 provides many advantages to the preferred embodiment of the device. By placing this means substantially adjacent to the wall, the flow of air is uninterrupted by this means which is substantially concealed behind inwardly depending flange 36. ~y configuring the rods 10 60 as shown in the top cross-section in Figure 6 spaced apart :
portions are provided to slide along the inner surface of the side wall 48 while a parallel spaced apart pivot surface is provided to retain the rivet-shaped pivot shown in Figure 6.
The pivot 206 is seen to have a rounded heat and, in one embodi- ~
ment, may not be fastened in any manner to either rod 60 or its :
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associated bracket since the retention of the rod against the side wall 48 makes it impossible for the pivot 206 to fall out or become otherwise disassociated with the device. Further, , .
~ the fact that parallel spaced apart sliding portions are disposed , - 20 on the rod prevents the rod 60 from twisting with respect to the side wall 48, thereby minimizing wear on the pivot itself. By~
slightly foreshortening the inner blade section 22b as seen in ~ -~
Figure 5 so that in the open pos:ition, that blade section will ;
clear the appropriate portion of the rod 60. The entire linkage is now neatly contained in the frame behind the inwardly depending ~ ~-`", ' -.
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flange as illustrated in Figures 4, 5, and 6. This interlocking linkage assembly therefore proyides many adyantages over prior art devices, including the additional advantage of being easily assembled. Base portion ~Q0 as well as base portion 202 extend substantially parallel to each other and are disposed against the inner surfaces of both the inner blade section 22b and the outer blade section 22a, these blade sections being riveted by rivets 215 to each of these sections of the blade. Each set of rivets 215 will fixedly engage the base 200 and base 202 to portions of the respective sections of the blade in a line which - is substantially parallel to the side wall 48 of the frame, here-by reducing the possibility that any torques could be created on the blade which would tend to unnecessarily distort or tend to distort the aforementioned hinge elements. Another advantage over the prior art with respect to the linkage means of the pre- ~
sent invention is that the linkage is neatly contained within the -frame, and more particularly, is disposed so that the linkage is substantially contained between the plane of the blades in the closed position and the tips of the inwardly extending blade ~
20 portions in the open position. It is therefore possible to con- -.
` struct a damper having an overall required depth of clearance i .
which is no greater than that which is re~uired to facilitate the ~-` rotation of the blades, while at the same time, providing a ., .
linkage means which is substantially disposed between the side wall of the frame and a plane parallel to the innermost edge of the appropriate inwardly depending flange~ With the exception :; :
of the portions of the blade engaging brackets, namely the bases 200 and 202, which lie flat against and therefore do not inter- ~ ;
fere with the air flow through the damper, substantially all of the linkage means is disposed behind the inwardly depending flange ` and therefore, out of the flow of air through the device.
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96~16 In order to clear inwardly depending flange 36, as seen in Figure 5, a diagonal portion 217 is formed in each blade engaging bracket so that the base portion 202 -of each blade engaging bracket will not interfere with any portion of inwardly depending flange 36. This diagonal :.:
portion 217 is also clearly illustrated in Figure 6 which is a top cross-sectional cut-away view of a portion of a means for articulating the blades with respect to each other and with respect to the frame.
In order to close off the air chamber to form a seal between the outer section 22a of each blade and the .. :~
respective associated portion of inwardly depending flange 36, a crimping process is utilized to crimp terminal portion 219 of outer section 22a of the blade so that a continuous seal is formed therebetween. Additionally, a notch may be . :.
formed, somewhat reducing the longitudinal dimension of a .
. portion of the transverse portion 98, tip portion 100, and spoiler 102 as illustrated in Figure 7 in order to allow those portions to extend beyond the plane of inwardly .
: 20 depend.~ng flange 36 or, as illustrated in Figure 7, upwards from the plane of the.paper to effectuate the interengagement illustra~ed in Figure 4. Alternatively, notching may be replaced with a similar crimping process as illustrated for portion 219 in Figure 7 whereby a double seal will be ` formed between the overlapping blade outer section 22a and the inner section of the adjacent blade which section corresponds to 22b as . ~ .
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1396~6 illustrated in Fic3ure 7. 'I'he ootchin~ o~ inwardly dcl~cnding ~ . . .
L~_ flange 36 to form hook-shaped hinge element 80 is also clearly illustratcd in Fi'gure 7.
From the above description, it can be seen that an extremely effective seal is created between each of the blades, the adjacent blades contiguous thereto, and the respective surfaces of the in~ardly dependin~ flanges of the frame. -~s a result, an extremely effective rotating blade fire dampcr is accomplished which utili~es certain novel features as dis- ' closed herein to form an extremely rigid, effective fire resistant fire damper.
It will be understood t)-at vari.ous changes .in the ' ' details, materials and arrangement of parts which have been ~ :
described and illustrated in order to explain the nature of ; this invention may be made by t.hosQ skilled in the art within ~.
the principle and scope of the invention as expressed in the following claims. ,~
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Background of the Invention The present invention relates generally to the field of air control dampers, and more particularly, to those air control dampers which are intended to regulate the volume of air passed along a duct or plenum, or through an opening, and which damper is further adapted to prevent the passage of smoke or fire therethrough when the damper is in a closed position.
In particular, a suitable fire, smoke and air control damper should be easily operable to allow the flow of air therethrough at any of a desired number of pre-determined settings between the closed and open positions of the blades with respect to the frame. With respect to the fire and smoke control aspect of such a damper, it is also important that a damper be capabie of withstanding intense heat and/or air pressures which impinge on either ` side of the damper for substantial periods of time during a fire. Due to the extreme conditions to which such a damper is subjected, it is necessary to provide extremely strong blades and a very substantial frame which, toqether, form a tight, positive seal to effectively shut off the air duct, opening, or plenum. In Eact, due to the ~-deficiencies experienced by some practitioners in this field, folding blade fire dampers have been utilized in order to overcome those deficiencies otherwise encountered by some devices utilizing a plurality of rotating blades, ` each of which blades must form a seal with an adjacent blade as well as the frame, which seal is sometimes prone to leakage in the event that extremely precise alignments and tolerances are not maintained. This problem has been ''.,: .
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accentuated by the fact that a smoke and fire damper mus-t function effectively years after it is installed in a relatively dirty environment.
Prior art rotating blade fire and smoke dampers have therefore incorporated extremely heavy materials which are not subject to easy bending or deformation in the presence of heat. The blades are mounted by distinct hinge or pivot means which are separately installed for the purpose of aligning each of the blades for rotational movement and to ensure the interengagement of each blade with its adjacent blade to form a seal therebetween which does not open in the presençe of heat or excessive pressures, such as those which might be encountered during a fire.
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Summary of the Invention The present invention overcomes many of the disadvantages of prior art fire, smoke and air control dampers by providing -in an air control damper comprising a frame, a plurality of blades and rotation means for allowing selective rotational displacement of each of said blades between an open and closed position with respect to said frame, the improvement wherein contiguous portions of adjacent blades are configured to form a seal therebetween when said blades are in the closed position, and to substantially maintain said seal through a predetermined arc of blade rotation as said blades ~-~
are moved from the closed position towards the open position, ~`
the longitudinal edges of adjacent blades being configured to form opposing hook shaped portions, the tip of each hook shaped portion being configured to engage an interior surface of the hook shaped portion of its adjacent blade in the closed position.
Unlike prior art fire dampers, the present invention is readily constructed from relatively light sheet metal materials.
Embodiments of the invention are illustrated in the accompanying drawings. ~;
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Brief Description of the Drawings Figure 1 is a top view of the preferred embodiment of the present invention disposed adjacent to an air flow opening shown in phantom, which opening is broken away;
E`igure 2 is a front view of the preferred embodiment of ;:~
the present invention;
Figure 3 is a back view of the preferred embodiment of ~ -the present invention as shown in Figure 1, taken as indicated ; by the lines and arrows 3-3 in Figure l;
Figure 4 is a greatly enlarged cross-section of a : ~ -portion of the preferred embodiment of the present invention illu-strated in Figure 2, taken as indicated by the lines and arrows 4-4 in Figure 2, and further wherein the open position of the blades with respect to the frame is shown in phantom;
~igure 5 is an enlarged cut~away back view of the preferred .
embodiment of the present invention as illustrated in Figure 4, : taken as indicated by the lines and arrows 5-51in Figure 4; ::
Figure 6 is an enlarged cross-sectional top view of a .
portion of the preferred embodiment as illustrated in Figure 4, taken as indicated by the lines and arrows 6-6 in Figure 4;
Figure 7 is a greatly enlarged perspective view of a portion of the preferred embodiment of the present invention wherein a portion of the frame has been cut away to show the hinge detail. ; :
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96g6 Detailed Description of the Drawings Referring now to all the figures, and in particular, to Figure 1, the damper of the present invention in its pre-ferred embodiment is a generally box-shaped damper for disposi-tion in an opening which in Figure 1 is diagrammatically illu-strated by wall sections 10 and 12. The damper, designed generally 14 in the drawings, comprises a frame designated generally 16 and a plurality of blades 18, 22, 26, and 30. The frame designated ; generally 16 comprises inwardly depending flanges 34 and 36 which are disposed on opposite sides-of the frame 16 in a plane which is substantially parallel to the plane of the blades 18, 22, 26, ~ -and 30 in the closed position. Additional inwardly depending flànges 38 and 40 are also formed in this plane at the top and , ` bottom of the frame. The first of tbe aforementioned inwardly depending flanges 34 and 36 (the side flanges) are adapted to form a seal with the ends of blades, while the last of the aforementioned in-wardly depending flanges 38 and 40 form seals with top and bottom ., blades 18 and 30 when those blades are in the closed position.
In constructing frame 16 the appropriate portions of the inwardly 20 depending flanges 34, 36, 38, and 40 are notched so that when folded into the aforementioned plane, a seal if formed at inter-.
sections 42 by welding, crimping or some other similar suitablemethod. The frame designated generally 16 further comprises a top 4~, a bottom, and sides 46 and 48 which extend generally per-pendicularly to inwardly depending flanges 34 and 36 respectively.
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. ,, ' ' ' ~ ': ',, The construction and assembly of the frame is generally similar to that described in my previously issued U.S. Patent No. 3,833,989 entitled "Method of Fabricating and Assembling a Damper."
Referring now to Figure 3 which is a back view of the preferred embodiment of the present invention, additional inwardly depending top and bottom back flanges 50 and 52 are illustrated to-gether with inwardly depending back-side flanges 54 and 56. For clarity, a major portion of back-side flange 56 has been cut away in order to clearly illustrate the means for articulating each of the blades with respect to each other and with respect to the frame. These back flanges are generally parallel to the aforemen- -tioned inwardly depending flanges 34, 36, 38, and 40 and provide means for mounting the damper on a wall such as illustrated in Figure 1 by using screw slots 58. The means for simultaneously articulating or rotating each of the blades 18, 22, 26, and 30 with respect to each other and with respect to the frame is clearly illustrated. This means is preferably disposed against an interior `
; surface of side wall 48 of the frame, said means generally com~
prising blade engaging brackets 19, 23, 27, and 31, which brackets are pinned for rotational movement with respect to rod 60. Rod 60 ` in turn is appropriately movable along an axis parallel to the axis . ~ .
defined by double-ended arrow A in Figure 3 to cause , ~ -:.
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each of the blades to assume a preselected orientation with respect to the frame7 Referring now to Figure 4~ which is a cross~section of a portion of the preferred embodiment sho~n in Figure 2, the relative positions of the blades are shown in two different positions. Blade 22 and a portion of blades 18 and 26 are shown disposed in the closed position with respect to inwardly depending ~;~
flange 36. In a phantom view, blades 22 and 26 are rotated to .. . .
the open position, which opening is accomplished by movement of 10 rod 60 along the axis as indicated by arrow D in Figure 4 to the ;
phantom position.
Referring now specifically to the particular blade con-figuration utilized in the preferred embodiment of the present invention, the blade designated generally 22 has disposed inter- ~
mediate between the two longitudinal edges thereof a hinge portion - ;
designated generally ~2. This hinge portion may be roll formed in the blade extending longitudinally across its length. Hinge portion 62 generally comprises hinge tip 64, rounded portion 66, blade offset 68 and overlapping portion 70. My previously issued patent, U.S. Patent No. 3,908,529, disclosed a backdraft damper with a particuIar blade frame hinging interaction.
As seen in Figure 4, each blade, such as blade 22, -is defined by the hinge portion designated generally 62 into two distinct sections: a first outer blade section 22a disposed between the hinge portion designated generally 62 and first blade ;
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tip 70; and a second inner blade section 22b which is disposed generally between the hinge portion designated generally 62 and second blade~tip 72~ As: clearly illustrated in Figure 4, the inner blade section 22b and the outer blade section 22a are parallel and sli~htly spaced apart, which spacing is generally :
established by the configuration of hinge portion 62 and in parti-cular by the length of blade off-set 68~ In the preferred embodi-ment as shown in Figure 4, the outer blade section 22a and inner blade section 22b are spaced apart by a dis~tance which is sub-stantially equal to the thickness of the inwardly depending flange ; designated generally 36 in Figure 4, Inwardly depending flange 36 is formed into a hook-shaped hinge element designated generally 80, which hinge element is formed by notching the appropriate ,., portions of inwardly depending flanges 34 and 36 on opposite sides so that each of the hinge elements such as hook-shaped hinge ele-ment 80 are disposed on opposite sides of the frame for engagement in articula-ted rotational relationship with hinge portion 62 of each respective blade.
By so constructing each of the blades in a rotating blade fire damper so that a hinge portion is, as shown in Figure 4, generally ~ormed intermediate between che tips of the blade, and then by correspondingly off~setting each of two sections of that blade by the width of the associated : inwardly depending flanges of that blade, it is possible .: ,:
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., ' 9~;96 to form an effective seal alon~ the ends of each of said blades which are contiguous to said inwardly depending flanges. As shown in Figure 4, inner blade section 22b is firmly pressed up against the inner surface of inwardly depending flange 36. Following the blade downwards along flange 36, overlapping portion ~0 of the hinge portion designated generally 62 is seen to form a seal between it and the interior surface of the base of the hook-shaped hinge element designa-ted generally 80 formed in the flange.
~herefore, the inner blade section and the overlapping portion of the hinge portion 62 form a seal with the inner -surface of inwardly depending flange 36, while the blade off-set 68 extends outwardly beyond the outer surface of - ~ - ~-inwardly depending flange 36 so that the outer blade section 22a will, when the blade is in the closed position, form a seal between the blade and an outer surface of inwardly depending flange 36.
Another f~eature of the present invention is in ; the unique sealing arrangement which is effected between adjacent blades along the portions of those blades adjacent to their longitudinal edges. Each longitudinal edge portion of said blade designated generally 90 for blade 22 is formed into a hook-shaped configuration. Each of the `~ hook-shaped configurations formed on these longitudinal . .
i edge portions open towards the inwardly depending flange .! 36. For example, a fir$t upper longitudinal edge portion ` 90 opens towards the inwardly depending flange 36.
` Similarly, the other longitudinal edge portion designated generally 90 opens in the opposite direction from the first longitudinal edge portion 90, but nonetheless towards : ' ,'; '::
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9~96 inwardly depending flange 36 due -to the disposition of - outer blade section 22a on the opposite side of inwardly ` depending flange 36. Each of the longitudinal end portions of a particular blade are formed into a plurality of portions which portions act to form a chamber or chambers 92 which are "dead air" chambers formed between the longitudinal edge portions of adjacent blades when those blades are in the closed position. Therefore, offsetting portion 94, extension portion 96, transverse portion 98 and tip 100 are formed to coact with the analogous portions on an adjacent blade in the closed.position to form the aforementioned chamber 92. In particular, the function of offsetting portion 94 is to move the interior surface of extension portion 96 away from the plane of the contiguous section of the blade so that upon the slight misalignment and/or slight opening of the blades, the leading edge of the blade (i.e., the edge formed at the intersection of the transverse portion 98 and the tip 100) will move in an arc substantially -parallel to the surface of the offsetting portion 94 so that a seal will be substantially maintained through an arc of the leading edge having a length of approximately bne-half of the length of the offsetting portion. In . :-alternate embodlments, the of~setting portion may be curved or otherwise shaped to more closely approximate the arc of the leading , ' ' ~ "
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6~6 edge to thereby maximize the wiping action thereof. The length of the offsetting portion may similarly be varied depending upon the desired arc of blade rotation while maintaining the double seal between the blades. A serpentine air path will also be formed as the blades open slightly beyond said arc or in the event of leakage between the leading edge and the offsetting portions, which poses maximum resistance to air impinging on either side of the fire damper. As previously mentioned, a double seal is also formed between the tips lOQ of adjacent blades and the interior surface of the extension portions 96 of adjacent blades, each of which is parallel to but spaced apart from the plane of their adjacent blade sections when the blades are in the fully closed position.
Transverse portions 98 of adjacent blades are substantially ; parallel to each other when said blades are in the closed postion, thereby imparting, together with the aforementioned portions, a cross-sectional configuration to chamber g2 which is a parallelogram having its shorter parallel sides formed : .
by tipfi lOQ and extension portions 96 and longer sides formed by transverse portions 98. Spoilers 102 are additionally disposed on each of the tips lOQ which act to increase the turbulence of the air which would tend to pass through the chamber 92 in the aforementioned serpentine fashion as the blades are moved as aforesaid. Thus, a double seal will exist as long as the tip lOQ of one blade is disposed coplanar with or on the opposite side of the plane defined by the con~
tiguous section of the adjacent blade. ;
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Referring now to the means for articulating the blades with respect to each other and with respect to the frame, blade engaging brackets 23 and 27 are illustrated in Figure ~, and are seen to comprise base portions 200 and 202 which are offset to firmly engage the respective blade sections and are r~veted thereto. Extending generally away in a tri-angular manner from base portions 200 and 202 towards a ful-crum point 203 at which a pivot 206 is disposed, these blades engaging brackets are connected pivotally with rod 60 so that upon movement of any one of the aforementioned blades or of the rod 60 along the axis as indicated by arrow B in Figure 4, each of the blades moves to a position such as the position shown in phantom in Figure 4 which has been referred to herein as "the open position" of the blades with respect to the frame.
In this position, the relative proportions of the hook-shaped .
portions formed on the longitudinal edge portions 90 of each of the blades is seen to be relatively minor with respect to the width of the blades, thereby permitting air to freely pass through the damper when the damper is in the open position. Disposed between base portions 200 and 202 of each of the blade engaging brackets is in arcuate cut-out 204 which allows clearance for the aforementioned hinge portion designated generally 62 of èach of the respective associated blades.
Referring now to Figure 5 which is an enlarged :'. ':, " '`, : ' -13~
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9~i~6 cut-away back view of one of the blade enga~ing brackets, namely blade engaging ~racket desi~nated generally 23, it will be seen that rod 60 is disposed substantially adjacent to side wall 48. The placement of rod 60 substantially adjacent to side wall 48 provides many advantages to the preferred embodiment of the device. By placing this means substantially adjacent to the wall, the flow of air is uninterrupted by this means which is substantially concealed behind inwardly depending flange 36. ~y configuring the rods 10 60 as shown in the top cross-section in Figure 6 spaced apart :
portions are provided to slide along the inner surface of the side wall 48 while a parallel spaced apart pivot surface is provided to retain the rivet-shaped pivot shown in Figure 6.
The pivot 206 is seen to have a rounded heat and, in one embodi- ~
ment, may not be fastened in any manner to either rod 60 or its :
. ,~ ..
associated bracket since the retention of the rod against the side wall 48 makes it impossible for the pivot 206 to fall out or become otherwise disassociated with the device. Further, , .
~ the fact that parallel spaced apart sliding portions are disposed , - 20 on the rod prevents the rod 60 from twisting with respect to the side wall 48, thereby minimizing wear on the pivot itself. By~
slightly foreshortening the inner blade section 22b as seen in ~ -~
Figure 5 so that in the open pos:ition, that blade section will ;
clear the appropriate portion of the rod 60. The entire linkage is now neatly contained in the frame behind the inwardly depending ~ ~-`", ' -.
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flange as illustrated in Figures 4, 5, and 6. This interlocking linkage assembly therefore proyides many adyantages over prior art devices, including the additional advantage of being easily assembled. Base portion ~Q0 as well as base portion 202 extend substantially parallel to each other and are disposed against the inner surfaces of both the inner blade section 22b and the outer blade section 22a, these blade sections being riveted by rivets 215 to each of these sections of the blade. Each set of rivets 215 will fixedly engage the base 200 and base 202 to portions of the respective sections of the blade in a line which - is substantially parallel to the side wall 48 of the frame, here-by reducing the possibility that any torques could be created on the blade which would tend to unnecessarily distort or tend to distort the aforementioned hinge elements. Another advantage over the prior art with respect to the linkage means of the pre- ~
sent invention is that the linkage is neatly contained within the -frame, and more particularly, is disposed so that the linkage is substantially contained between the plane of the blades in the closed position and the tips of the inwardly extending blade ~
20 portions in the open position. It is therefore possible to con- -.
` struct a damper having an overall required depth of clearance i .
which is no greater than that which is re~uired to facilitate the ~-` rotation of the blades, while at the same time, providing a ., .
linkage means which is substantially disposed between the side wall of the frame and a plane parallel to the innermost edge of the appropriate inwardly depending flange~ With the exception :; :
of the portions of the blade engaging brackets, namely the bases 200 and 202, which lie flat against and therefore do not inter- ~ ;
fere with the air flow through the damper, substantially all of the linkage means is disposed behind the inwardly depending flange ` and therefore, out of the flow of air through the device.
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., ., . ~, ., . , . : . :
96~16 In order to clear inwardly depending flange 36, as seen in Figure 5, a diagonal portion 217 is formed in each blade engaging bracket so that the base portion 202 -of each blade engaging bracket will not interfere with any portion of inwardly depending flange 36. This diagonal :.:
portion 217 is also clearly illustrated in Figure 6 which is a top cross-sectional cut-away view of a portion of a means for articulating the blades with respect to each other and with respect to the frame.
In order to close off the air chamber to form a seal between the outer section 22a of each blade and the .. :~
respective associated portion of inwardly depending flange 36, a crimping process is utilized to crimp terminal portion 219 of outer section 22a of the blade so that a continuous seal is formed therebetween. Additionally, a notch may be . :.
formed, somewhat reducing the longitudinal dimension of a .
. portion of the transverse portion 98, tip portion 100, and spoiler 102 as illustrated in Figure 7 in order to allow those portions to extend beyond the plane of inwardly .
: 20 depend.~ng flange 36 or, as illustrated in Figure 7, upwards from the plane of the.paper to effectuate the interengagement illustra~ed in Figure 4. Alternatively, notching may be replaced with a similar crimping process as illustrated for portion 219 in Figure 7 whereby a double seal will be ` formed between the overlapping blade outer section 22a and the inner section of the adjacent blade which section corresponds to 22b as . ~ .
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~::
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.
1396~6 illustrated in Fic3ure 7. 'I'he ootchin~ o~ inwardly dcl~cnding ~ . . .
L~_ flange 36 to form hook-shaped hinge element 80 is also clearly illustratcd in Fi'gure 7.
From the above description, it can be seen that an extremely effective seal is created between each of the blades, the adjacent blades contiguous thereto, and the respective surfaces of the in~ardly dependin~ flanges of the frame. -~s a result, an extremely effective rotating blade fire dampcr is accomplished which utili~es certain novel features as dis- ' closed herein to form an extremely rigid, effective fire resistant fire damper.
It will be understood t)-at vari.ous changes .in the ' ' details, materials and arrangement of parts which have been ~ :
described and illustrated in order to explain the nature of ; this invention may be made by t.hosQ skilled in the art within ~.
the principle and scope of the invention as expressed in the following claims. ,~
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Claims (13)
1. In an air control damper comprising a frame, a plurality of blades and rotation means for allowing selective rotational displacement of each of said blades between an open and closed position with respect to said frame, the improvement wherein contiguous portions of adjacent blades are configured to form a seal therebetween when said blades are in the closed position, and to substantially maintain said seal through a predetermined arc of blade rotation as said blades are moved from the closed position towards the open position, the longitudinal edges of adjacent blades being configured to form opposing hook shaped portions, the tip of each hook shaped portion being configured to engage an interior surface of the hook shaped portion of its adjacent blade in the closed position.
2. The invention of Claim 1 wherein said frame further comprises an inwardly depending flange and wherein each of said blades forms a seal along opposite sides of said flange in the closed position.
3. The invention of Claim 2 wherein said hook shaped portion further comprises an offsetting portion extending generally away from the intersection of the adjacent blade section with said flange.
4. The invention of Claim 3 wherein said hook shaped portion of said blade further comprises extension, transverse and tip portions, said transverse portion extending between said extension portion and said tip portion, said extension portion and said tip portion being adapted to sealingly mate with the respective tip and extension portions of an adjacent blade.
5. In an air controlled damper having a frame, a plurality of blades and rotation means for allowing selective rotational displacement of said blades with respect to said frame between open and closed position, the improvement wherein said frame comprises an inwardly depending flange disposed within a plane which is parallel to the plane of said blades in the closed position and wherein first and second substantially parallel blade section sealingly engage first and second opposing side of said inwardly depending flange when said blades are in a closed position, the longitudinal edges of adjacent blades being configured to form opposing hook shaped portions, the tip of each hook shaped portion being configured to engage an interior sur-face of the hook shaped portion of its adjacent blade in the closed position and to cooperate with a portion of said interior surface to wipe across at least a portion of said surface through a predetermined arc of blade rotation as the blades are moved from the closed towards the open position whereby a double seal is maintained in the closed position and through said predetermined arc of blade rotation.
6. The invention of Claim 5 wherein said tip further com-prises a substantially planar surface which is parallel and offset from the plane of said blade, and wherein the interior surface of said hook shaped portion of each adjacent blade comprises a complimentally configured surface which sealingly mates with said tip portion when said blades are in the closed position.
7. The invention of Claims 1 or 5 wherein said hook shaped portion further comprises a spoiler for increasing the fluid frictional resistance of the air path initially formed as said blades move from the closed towards the open position.
8. The invention according to Claim 1, further comprising linkage means for articulating the position of two or more of said blades with respect to each other during the rotation thereof, wherein said linkage means comprises a plurality of blade engaging brackets one for each blade and a linkage rod pivotally attached to said brackets in sliding engagement with at least one interior surface of said frame.
9. The invention of Claim 8 wherein said brackets retain said rod against said interior surface of said frame for sliding engagement therewith.
10. The invention of Claim 8 including a pivot pin for establishing the pivotal attachment of said rod to each said bracket and wherein said rod is so shaped as to retain said pivot pin in position between a portion of said rod and said interior surface.
11. The invention of Claim 8 wherein said frame comprises at least one side wall and one inwardly depending flange therefrom and wherein said linkage means is disposed adjacent to said side wall between said wall and the parallel plane defined by the inward most edge of said inwardly depending flange whereby the flow of air through said damper in the open position is substantially unimpeded by said linkage means.
12. The invention of Claim 11 wherein at least a portion of that portion of each of said blades which rotates away from the inwardly depending flange in the direction of said side wall is foreshortened with respect to the remainder of said blade by a distance sufficient to provide clearance for said linkage means but less than the width of said inwardly depending flange whereby a seal is maintained in the closed position between said foreshortened portion of said blade and said inwardly depending flange.
13. The invention of Claim 1, 2 or 5, further comprising pivot means for allowing selective rotational displacement of each of said blades between a closed and an open position and linkage means for articulating the position of two or more of said blades with respect to each other during the rotation thereof, wherein said linkage means comprises a plurality of blade engaging brackets, one for each blade and a linkage rod pivotally attached to said brackets, in sliding engagement with at least one interior surface of said frame, and wherein said frame further comprises at least one side wall and one inwardly depending flange therefrom, said linkage means being disposed adjacent to said side wall between said side wall and a parallel plane defined by the inward most edge of said inwardly depending flange, whereby the flow of air through said damper in the open position is substantially unimpeded by said linkage means, at least a portion of that portion of each of said blades which rotates away from said inwardly depending flange in the direction of said side wall being foreshortened with respect to the remainder of said blade by a distance sufficient to provide clearance for said linkage means but less than the width of said inwardly dependent flange whereby a seal is maintained in the closed position between the foreshortened portion of said blades and said inwardly depending flange.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA333,584A CA1089696A (en) | 1976-05-26 | 1979-08-10 | Rotating blade fire damper |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/689,994 US4081173A (en) | 1976-05-26 | 1976-05-26 | Rotating blade fire damper |
| US689,994 | 1976-05-26 | ||
| CA272,088A CA1065671A (en) | 1976-05-26 | 1977-02-18 | Rotating blade fire damper |
| CA333,584A CA1089696A (en) | 1976-05-26 | 1979-08-10 | Rotating blade fire damper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1089696A true CA1089696A (en) | 1980-11-18 |
Family
ID=27164918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA333,584A Expired CA1089696A (en) | 1976-05-26 | 1979-08-10 | Rotating blade fire damper |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1089696A (en) |
-
1979
- 1979-08-10 CA CA333,584A patent/CA1089696A/en not_active Expired
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| MKEX | Expiry |