U.S. patent application number 09/867116 was filed with the patent office on 2001-10-11 for hvac damper.
Invention is credited to Stone, Garrick S., Stone, William L..
Application Number | 20010027814 09/867116 |
Document ID | / |
Family ID | 46257769 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010027814 |
Kind Code |
A1 |
Stone, William L. ; et
al. |
October 11, 2001 |
HVAC damper
Abstract
A fail-safe HVAC damper apparatus comprises a duct channel with
a closure comprising one or more quadri-panel hinged elements, each
with four panels connected by four parallel hinge pins. A gear
shaft with a toothed gear is controllably rotated to linearly drive
a spring-biased plate to move one of the hinge pins of each
quadri-panel element between an open and a closed position. A
damper may use blades of different sizes and be driven to begin an
opening and/or closing action sequentially and/or very gradually. A
drive motor may be activated to open or close the closure, e.g. by
a smoke detector or other controller. Melting of a fuse in the duct
channel serves to disengage a gear from a gear shaft, enabling a
spring mounted plate to move the hinged elements to a default
closed (or alternative open) safety position. Various gear shaft
and gear structures are shown.
Inventors: |
Stone, William L.; (Grand
Junction, CO) ; Stone, Garrick S.; (Palisade,
CO) |
Correspondence
Address: |
Allen H. Erickson
3493 Dayton Terrace South
Inverness
FL
34452
US
|
Family ID: |
46257769 |
Appl. No.: |
09/867116 |
Filed: |
May 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09867116 |
May 29, 2001 |
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09352235 |
Jul 13, 1999 |
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6237630 |
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Current U.S.
Class: |
137/601.12 |
Current CPC
Class: |
F24F 13/10 20130101;
F16K 51/02 20130101; F24F 2013/1446 20130101; F16K 17/383 20130101;
Y10T 137/87491 20150401 |
Class at
Publication: |
137/601.12 |
International
Class: |
F16K 001/22 |
Claims
What is claimed is:
1. A damper apparatus for controlling gas flow in a duct,
comprising: inner walls defining an inner channel for confining a
gas flow between inlet and outlet openings; a closure operable
between an open position and a closed position, said closure
comprising at least one blade formed of four elongate panels hinged
to each other to be rotatable relative each other about four
parallel axes; a stationary hingepin hingedly joining first and
second panels, said stationary hingepin having its ends mounted in
opposing inner walls of said channel; a first linear slot in an
inner wall of said channel; a drive hingepin hingedly joining third
and fourth panels, said drive hingepin having one end passing
through said first linear slot in a first wall of said opposing
inner walls and configured to be linearly movable therein for
closing and opening said closure; a first floating hingepin
hingedly joining said first and third panels; a second floating
hingepin hingedly joining said second and fourth panels; wherein
said stationary hingepin is positionally opposed to said drive
hingepin, and said floating hingepins are positionally opposed; a
first drive member exterior of said first wall and generally
parallel thereto, said one end of drive hingepin mounted to said
first drive member to be linearly moved thereby, said first drive
member including a toothed surface; a rotatable gear shaft mounted
to pass through said first wall; and a gear assembly mounted on
said gear shaft wherein said gear assembly meshes with said toothed
surface to linearly move said first drive member and thereby
control said closure between an open position and a closed
position.
2. The damper apparatus according to claim 1, further comprising a
biasing means to bias said closure to one of an open position and a
closed position.
3. The damper apparatus according to claim 2, wherein said biasing
means comprises a coil spring.
4. The damper apparatus according to claim 2, wherein said biasing
means is attached to said first drive member and to a wall of said
damper.
5. The damper apparatus according to claim 1, wherein said inner
channel is substantially rectangular in cross-section.
6. The damper apparatus according to claim 1, further comprising
means for rotating said drive shaft.
7. The damper apparatus according to claim 6, wherein said means
for rotating said drive shaft comprises a manually operated
device.
8. The damper apparatus according to claim 6, wherein said means
for rotating said drive shaft comprises a motorized positioner with
rotating output having controllable start and stop limits.
9. The damper apparatus according to claim 6, wherein said means
for rotating said drive shaft comprises a motorized positioner with
rotating output controllable to position said closure at values
between fully open and fully closed.
10. The damper apparatus according to claim 8, wherein said
motorized positioner is configured to receive a signal indicating
the presence of smoke and to move said closure to a fully closed
position, and to maintain said closed position until manually
reset.
11. The damper apparatus according to claim 1, wherein the width of
said panels differs by less than about 5 percent.
12. The damper apparatus according to claim 1, wherein the width of
all panels of a blade are substantially equal.
13. The damper apparatus according to claim 1, further comprising:
a first linear guide slot in said first drive member, said
stationary hinge pin passing through said first linear guide slot
to restrict movement of said first drive member; a second linear
guide slot in said first drive member proximate said gear assembly;
and a guide pin mounted on said first wall and passing through said
second linear guide slot to urge said toothed surface against said
gear assembly; wherein said slots in said first wall and in said
first drive member are parallel, and movement of said stationary
hinge pin, drive hinge pin, and guide pin maintain said first drive
member in a linear path parallel thereto.
14. The damper apparatus according to claim 2, further comprising
means for disconnecting said gear from said gear shaft to permit
said closure to rapidly move to one of a default open position and
a default closed position by force of said biasing means.
15. The damper apparatus according to claim 14, wherein said
disconnecting means is thermally actuated.
16. The damper apparatus according to claim 14, wherein said damper
apparatus is one of a fire damper and a combination fire/smoke
damper.
17. The damper apparatus according to claim 14, wherein said
disconnecting means comprises: a gear wheel with a cylindrical
external toothed surface and an internal axial hole; a
substantially hollow gear shaft passing through said internal axial
hole and rotatable within said gear wheel; a circular chamber
within said gear wheel extending radially from said gear shaft; at
least one slot chamber axially directed from said circular chamber;
at least one longitudinal slot in said gear shaft extending
longitudinally between said circular chamber and said slot chamber;
a cog axially movable within said hollow gear shaft, said cog
comprising an axial cog body with at least one radial finger
extending through said longitudinal slot into one of said circular
chamber and slot chamber; biasing means to bias said cog and radial
finger to said circular chamber; means to retain said cog against
said biasing means to retain said radial finger in said slot
chamber; and means to release said cog from said retaining means;
wherein movement of said radial finger from said circular chamber
into said slot chamber motively joins said gear shaft to said gear
wheel and biased movement of said radial finger from said slot
chamber into said circular chamber disconnects said gear shaft from
said gear wheel.
18. The damper apparatus according to claim 17, further comprising:
a connector fixed to said cog and forcibly maintained in a position
whereby said at least one cog finger is seated within said at least
one slot chamber; and a device connected to said connector for
releasing said connector under a predetermined abnormal
condition.
19. The damper apparatus according to claim 18, wherein said
abnormal condition comprises excessively high temperature.
20. The damper apparatus according to claim 18, wherein said device
comprises a thermal fusible link meltable at a predetermined
temperature.
21. The damper apparatus according to claim 18, wherein said
connector comprises a ligature passing from said cog to be attached
to a fusible link connected to said shaft within said inner
channel.
22. An apparatus for selectively connecting and disconnecting a
gear wheel and a shaft passing axially therethrough, said apparatus
comprising: a gear wheel with a cylindrical external toothed
surface and an internal axial hole; a substantially hollow gear
shaft passing through said internal axial hole and rotatable within
said gear wheel; a circular chamber within said gear wheel
extending radially from said gear shaft; at least one slot chamber
axially directed from said circular chamber; at least one
longitudinal slot in said gear shaft extending longitudinally
between said circular chamber and said slot chamber; a cog axially
movable within said hollow gear shaft, said cog comprising an axial
cog body with at least one radial finger extending through said
longitudinal slot into one of said circular chamber and slot
chamber; biasing means to bias said cog and radial finger to said
circular chamber; means to retain said cog against said biasing
means to retain said radial finger in said slot chamber; and means
to release said cog from said retaining means; wherein movement of
said radial finger from said circular chamber into said slot
chamber motively joins said gear shaft to said gear wheel and
biased movement of said radial finger from said slot chamber into
said circular chamber disconnects said gear shaft from said gear
wheel.
Description
[0001] This application is a continuation-in-part of Ser. No.
09/352,235 filed Jul. 13, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to dampers for regulating
fluid flow. More particularly, the invention pertains to apparatus
for dampening gas flows in heating, ventilation and air
conditioning (HVAC) applications, including use as a smoke safety
damper and/or a fire safety damper.
[0004] 2. State of the Art
[0005] Variable flow dampers have been used for a long time to
control air flow rates in heating, ventilating and air conditioning
duct systems.
[0006] Depending upon the desired purpose, dampers may be quite
simple or relatively sophisticated and complex.
[0007] A simple "volume damper" is merely a duct insert with one or
more internal pivoting blades whose positions are set by a lockable
hand lever. Such blades are sometimes referred to as vanes or
louvers.
[0008] In a more sophisticated "motorized volume damper", the blade
position is controlled between an open and a closed position by a
shaft rotated by an actuating motor.
[0009] In a "smoke damper", the blades are activated when smoke is
detected, either within the duct or at some remote location.
Typically, the blade actuator motor is activated by a smoke
detector to tightly close the blades for minimum leakage. Locking
devices are provided to ensure that when in the closed position,
the blades will not open without manual intervention, generally
requiring access to the inside of the damper.
[0010] A "fire damper" is one which closes to prevent flames and
high temperature gases from rapidly spreading within a building.
Fire dampers are required by U.S. building codes to maintain the
required fire resistance ratings of walls, partitions and floors
wherever they are penetrated by an air duct. A fire damper must be
operable to close even when electric power has been interrupted.
Typically, a meltable fuse or thermostat releases the blades so
that they automatically slam shut under gravitational force or by a
spring at a predetermined temperature, typically about 165.degree.
F. (74.degree. C.). In actual practice, the flame temperatures
attained may destroy the elasticity of the biasing spring, making
it useless for keeping the blades shut under the overpressures
experienced.
[0011] Many fire dampers are built to be ON-OFF safety devices
only, and have no function in general flow control.
[0012] It is the view of some in the industry that in most
instances, current fire dampers merely act to provide a brief delay
in the spread of the conflagration, but any delay time, however
small, is of value in reducing injury or preventing loss of life.
In any case, current fire dampers rarely survive a fire.
[0013] Some dampers are designed to shut under either a smoke
detector signal or the presence of high temperature. These
"smoke-and-fire dampers" combine the features of both damper
types.
[0014] Volume dampers with single-hinged blades are shown in U.S.
Pat. No. 594,727 of Cooper, U.S. Pat. No. 2,320,007 of Otto, U.S.
Pat. No. 2,360,888 of Peple, Jr., U.S. Pat. No. 2,400,044 of
Hermanson, U.S. Pat. No. 3,847,210 of Wells, U.S. Pat. No.
4,592,535 of Magill et al., U.S. Pat. Nos. 4,472,999 and 4,555,981
of McCabe, U.S. Pat. No. 4,506,825 of Grant, U.S. Pat. No.
5,398,910 of Kitazawa, U.S. Pat. No. 5,921,277 of Bernal, and U.S.
Pat. No. 6,019,679 of Lloyd. None of these patents shows a damper
configured as a smoke damper or fire damper, with the exception of
the McCabe patents and the Lloyd patent. In McCabe, a single spring
biased blade is moved by a lever attached to a rotatable shaft. The
lever/shaft connection is shown as a serpentine bimetallic element
which when heated to a predetermined temperature, disconnects the
lever from the shaft, permitting the blade to close. The damper may
be used for maintaining an open position in the event of e.g. smoke
detection; the spring position is altered to bias the damper blade
to an open position. The damper cannot be used for opening the
blade under one stimulus, i.e. smoke and closing it under another,
i.e. fire, since the response depends upon the spring location.
Springs installed for each action would cancel each other.
[0015] Flexible damper louvers comprising flexible tubular members
expanded by internal pressure, movable rods or an engaging member
are shown in U.S. Pat. No. 3,329,163 of Barker et al., U.S. Pat.
No. 3,768,512 of Lahaye, and U.S. Pat. No. 5,123,435 of Blacklin et
al. Practical use of the Barker et al. and Blacklin et al.
inventions in a high temperature environment is difficult to
envision, and the Lahaye apparatus requires a very complex control
system. Furthermore, the flexible thin-skin metal or plastic vanes
of Barker et al. and Lahaye will not be very resistant to fire and
heat. In addition, repeated bending will lead to cracking and
breakage.
[0016] U.S. Pat. No. 3,412,755 of Mason describes a pressure
actuated valve for a duct wherein duct pressure closes the valve
against a force exerted by springs on each side of the duct.
[0017] U.S. Pat. No. 3,847,210 of Wells discloses a gear system for
simultaneously controlling three streams of gas.
[0018] U.S. Pat. No. 2,672,088 of Orr, U.S. Pat. No. 2,884,005 of
Honerkamp et al., U.S. Pat. No. 3,958,605 of Nishizu et al., U.S.
Pat. No. 4,457,336 of Allan et al. and U.S. Pat. No. 4,535,811 of
Wood et al. appear to show dampers with hingedly interconnected
blades of differing dimensions. No means for biasing the damper to
an open or closed position is disclosed.
[0019] The Allan et al. and Wood et al. patents show systems where
the blades fold into a framework with windows, and are actuated by
a cammed drive.
[0020] In Nishizu et al., a four-member vane device with six
hingepins and an internal biasing spring is used to maintain a
constant airflow, regardless of upstream pressure. An external
lever can be used to increase or decrease the spring tension.
[0021] In the Honerkamp et al. document, each vane device has four
vane panels of unequal dimensions, and a side hinge pin of each
vane device is connected to a transverse rod driven by a cam. The
apparatus results in a requirement for high applied leverage forces
to activate the damper.
[0022] The Orr reference describes a damper wherein four-member
blade structures have side hinge pins connected to a common member
which is moved transversely by a lever.
[0023] In each of the above references, the illustrated damper has
various shortcomings which limit it use. Where two of the four
members are substantially longer than the other members, the damper
will not have a fail-safe closure, because increased upstream
pressures may open the closure. This is illustrated in FIG. 1,
showing a duct 200 wherein a four-member closure 204 of damper 202
has stationary hinge pin 206, drive hinge pin 208, and side pins
210, 212 as shown. When used as a fire damper, drive hinge pin 208
is driven by a spring or other biasing means 214 to close. If the
damper 202 is mounted as shown with incoming gas stream 216, static
gas pressure 218 against the blade members 220 may open the closed
closure 204. If the damper 202 is mounted in the reverse order,
i.e. for incoming gas stream 222, the static force 224 tending to
open the closure 204 is much greater than the static force 226
tending to keep the closure closed. Thus, the damper 202 is not
fail-safe in the event of, for example, loss of the required
biasing spring force. Such might be expected in a fire.
[0024] U.S. Pat. No. 5,577,525 of Wirfel et al. discloses a damper
actuator having a thermal release apparatus. Melting of a thermal
fuse releases a spring for rotating a vane to a closed
position.
[0025] The need for a damper which may be used as a true fail-safe
smoke damper, fire damper, or combination smoke-fire damper in a
variety of modes is evident.
BRIEF SUMMARY OF THE INVENTION
[0026] The invention comprises a damper apparatus including
improved components of (a) damper blades (i.e. vanes) movable
between a closed and an open position by linear movement, (b)
apparatus for transforming rotary power to a linear movement, and
(c) apparatus for closing (or alternatively opening) the blades to
a fail-safe condition in a fire or intense heat. Various
embodiments of the damper apparatus are described which may be
installed in a duct carrying a gaseous fluid, e.g. heated or cooled
air in a heating/cooling system. The damper is configured so that
various devices may be readily added to convert the damper from a
simple manually controlled volume damper to a tight seal damper, a
motorized control damper, a smoke damper, a fire damper, or a
combination smoke-and-fire damper.
[0027] The damper apparatus has a positive closing feature whereby
once closed, increased upstream pressure merely increases the
sealing force to prevent opening. Thus, the damper closure will
remain in a default closed position even if the spring fails.
[0028] In an alternative embodiment, the damper apparatus has a
positive opening feature whereby the upstream pressure serves to
open and maintain the damper closure in a default open
position.
[0029] In a still further embodiment, the damper apparatus has a
locking feature in which, once closed, the damper blades will
remain closed despite either high upstream pressure or increased
downstream pressure. The closed position will be maintained even in
the event of spring failure.
[0030] A vane positioner may be e.g. a handwheel or lever for
manual operation, or may be motor-driven, and may be installed on
either of two opposite sides of the damper where the drive shaft
protrudes. The damper apparatus may be installed in the duct system
so that the vane positioner is on the top, bottom, or either side
of the damper apparatus.
[0031] The damper apparatus has an inner duct with open ends which
are configured to match the ductwork into which the damper is
installed.
[0032] Within the inner duct is a closure of one or more
quadri-hinge vanes or blades, each of which has four flat or
arcuate panels connected by hinge pins along four swivel axes. One
hinge pin has its ends mounted to be stationary, and one of the
other three movable hinge pins of each vane is actuated by a damper
controller to open and close the panels of the vane. Each panel is
a flat plane or slightly arcuate to produce a low resistance
airfoil in the open position. The vanes are equipped with blade
seals which effectively seal the vanes when closed. Each joint
between vanes may be sealed by one or more sealing element attached
to one or more of adjacent vanes.
[0033] In one embodiment, the central movable hinge pin is actuated
longitudinally by a driver member. Typically the driver member is a
slide assembly such as a linearly sliding plate. The slide plate
engages a movable hinge pin of each vane, moving each vane between
an open and a closed position. The slide assembly is normally
spring mountedly biased to a closed panel position, but may be
biased to the open position for certain applications. In one
embodiment, the slide assembly sequentially and progressively moves
each of a plurality of vanes to achieve very gradual opening and
closing actions. Thus, smooth transition from a no flow condition
to a flow condition, or from a full flow condition to a
partially-closed position, is achieved. In another embodiment, a
non-standard size damper may be formed with blades of different
sizes, and provide an exponential flow curve (percent opening vs.
percent linear actuation).
[0034] A gear shaft with a gear is rotated to linearly move the
driver member. The gear shaft may be controllably rotated manually
or by a motorized positioner with an electric motor for example.
The positioner may be actuated by a remote controller. For example,
a smoke detector may be used to actuate the positioner to e.g.
direct electrical power to the motor to close the damper closure.
The damper apparatus may be used as a fire damper, in which a
fusible link in the inner duct, when melted, disconnects the gear
from the gear shaft and the closure quickly closes under spring
force. Easy replacement of the fusible link permits an intact
damper apparatus to be reused following an emergency closure due to
fire or intense heat.
[0035] Some of the features illustrated and described herein relate
to, and are improvements to the disclosure of our prior application
Ser. No. 09/352,235 filed Jul. 13, 1999, which is incorporated by
reference herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The invention is illustrated in the following figures,
wherein the elements are not necessarily shown to scale.
[0037] FIG. 1 is a diagrammatic cross-sectional side view of a
damper of the prior art;
[0038] FIG. 2 is a perspective view of a damper apparatus of the
invention, shown in a HVAC duct;
[0039] FIG. 3 is a partially cutaway perspective view of a damper
apparatus of the invention;
[0040] FIG. 4 is a partially cut-away top view of a damper blade of
the damper apparatus of the invention;
[0041] FIG. 5 is a cross-sectional end view of a damper blade of
the damper apparatus of the invention in a closed position, as
taken along line 5-5 of FIG. 4;
[0042] FIG. 6 is a perspective end view of a damper blade seal
portion of the invention;
[0043] FIG. 7 is a perspective end view of another damper blade
seal portion of the invention;
[0044] FIG. 8 is a partial cross-sectional end view of two adjacent
damper blades of the invention showing the interaction of seals in
the closed position;
[0045] FIG. 9 is a schematic end view of a damper blade of the
invention showing movement between a fully closed position and a
fully open position;
[0046] FIG. 10 is a graphical view of an exemplary relationship
between the degree of actuation and the resulting gas flow area of
a damper in accordance with the invention;
[0047] FIG. 11 is a sectional side view of a damper control
compartment showing the drive train of a damper of the invention,
as taken along line 11-11 of FIG. 2;
[0048] FIG. 12 is a sectional side view of a damper control
compartment showing the drive train of another embodiment of damper
of the invention, as taken along line 11-11 of FIG. 2;
[0049] FIG. 13 is a partial upper cross-sectional view of a first
damper control compartment showing the drive train of a damper of
the invention, as taken along line 13-13 of FIG. 3;
[0050] FIG. 13A is a partial upper cross-sectional view of a second
damper control compartment of a damper of the invention, as taken
along line 13A-13A of FIG. 3;
[0051] FIG. 14 is an upper view of a portion of a damper drive
train in accordance with the invention;
[0052] FIG. 15 is a cross-sectional upper view of a portion of a
damper drive train along the central axis of a gear and gear shaft
of the invention, wherein the gear and gear shaft are motively
disconnected;
[0053] FIG. 15A is a cross-sectional upper view of another
embodiment of a gear shaft of the invention;
[0054] FIG. 16 is an axial cross-sectional view of a gear of the
invention, as taken along line 16-16 of FIG. 14;
[0055] FIG. 17 is an axial cross-sectional view of a gear of the
invention, as taken along line 17-17 of FIG. 14;
[0056] FIG. 18 is an axial cross-sectional view of a gear of the
invention, as taken along line 18-18 of FIG. 14;
[0057] FIG. 19 is an axial cross-sectional view of a gear of the
invention, as taken along line 19-19 of FIG. 14;
[0058] FIG. 20 is an axial cross-sectional view of a gear of the
invention, as taken along line 20-20 of FIG. 14;
[0059] FIG. 21 is a lateral cross-sectional view of a gear of the
invention, as taken along line 21-21 of FIG. 20;
[0060] FIG. 22 is a cross-sectional upper view of a portion of a
damper drive train along the central axis of a gear and gear shaft
of the invention, wherein the gear and gear shaft are motively
connected;
[0061] FIG. 23 is an end view of closed damper blades and inner
duct wall of another embodiment of the damper of the invention;
[0062] FIG. 24 is an enlarged partial end view of closed damper
blades and damper seal apparatus of the damper of another
embodiment of the invention;
[0063] FIG. 25 is an enlarged partial end view of open damper
blades and damper seals of another embodiment of a damper of the
invention;
[0064] FIG. 26 is a perspective view of partially closed damper
blades with split damper seals, in accordance with a damper of the
invention;
[0065] FIG. 27 is a perspective view of another embodiment of a
gear shaft of the invention;
[0066] FIG. 28 is a perspective view of a gear hub of the
invention;
[0067] FIG. 29 is a side cross-sectional view of another embodiment
of an assembled gear shaft and hub of a drive train shown in an
engaged position in accordance with the invention;
[0068] FIG. 30 is a cross-sectional view of a gear shaft and hub in
accordance with the invention, as taken along line 30-30 of FIG.
29;
[0069] FIG. 31 is a cross-sectional view of a gear shaft and hub in
accordance with the invention, as taken along line 31-31 of FIG.
29:
[0070] FIG. 32 is a cross-sectional view of a gear shaft and hub in
accordance with the invention, as taken along line 32-32 of FIG.
35;
[0071] FIG. 33 is a cross-sectional view of a gear shaft and hub in
accordance with the invention, as taken along line 33-33 of FIG.
29;
[0072] FIG. 34 is a cross-sectional view of a gear shaft and hub in
accordance with the invention, as taken along line 34-34 of FIG.
29;
[0073] FIG. 35 is a side cross-sectional view of an embodiment of a
gear shaft and hub of a drive train in a disengaged position in
accordance with the invention;
[0074] FIG. 36 is a cross-sectional view of a gear shaft and hub in
accordance with the invention, as taken along line 36-36 of FIG.
35;
[0075] FIG. 36A is a cross-sectional view of a gear shaft and hub
in accordance with the invention, as taken along line 36A-36A of
FIG. 29;
[0076] FIG. 37 is a side cross-sectional view of a further
embodiment of a gear shaft and hub of a drive train in an engaged
position in accordance with the invention;
[0077] FIG. 38 is a side cross-sectional view of a further
embodiment of a gear shaft and hub of a drive train in a disengaged
position in accordance with the invention;
[0078] FIG. 39 is a side view of a cog key for disengaging a gear
shaft and hub in a drive train of the invention;
[0079] FIG. 40 is a cross-sectional view of a cog key for
disengaging the gear shaft and hub in a drive train of the
invention, as taken along line 40-40 of FIG. 39;
[0080] FIG. 41 is an end view of a cog key for disengaging the gear
shaft and hub in a drive train of the invention;
[0081] FIGS. 42 and 43 are cross-sectional views of a cog key for
disengaging the gear shaft and hub in a drive train, as taken along
lines 42-42 and 43-43, respectively of FIG. 39;
[0082] FIG. 44 is a cross-sectional side view of another embodiment
of an engaged gear shaft and hub in a drive train of the
invention;
[0083] FIG. 45 is a cross-sectional view of an engaged gear shaft
and hub in a drive train of the invention, as taken along line
45-45 of FIG. 44;
[0084] FIG. 46 is an enlarged side view of a portion of an gear
shaft and hub of a drive train which has been disengaged, as
corresponding to region 46 of FIG. 44;
[0085] FIG. 47 is a cross-sectional view of a portion of a
disengaged gear shaft and hub of a drive train of the invention,
corresponding to the view of FIG. 45;
[0086] FIG. 47A is a cross-sectional view of a portion of an
engaged gear shaft and hub of a drive train of another embodiment
of the invention, corresponding to portion 46 of FIG. 44;
[0087] FIG. 48 is a cross-sectional view of a fixed gear shaft and
hub of a drive train of the invention, as taken along line 48-48 of
FIG. 49;
[0088] FIG. 49 is a perspective view of a fixed gear shaft and hub
of a drive train of the invention;
[0089] FIG. 50 is a side view of a fixed gear shaft and hub of a
drive train of the invention;
[0090] FIG. 51 is a cross-sectional view of a fixed gear shaft and
hub as connected in a drive train of the invention;
[0091] FIGS. 52 through 55 are side views of a progressive action
slide assembly in various stages of damper closure, in accordance
with a further embodiment of a damper of the invention;
[0092] FIG. 56 is a graphical view of an exemplary relationship
between the degree of actuation and the resulting gas flow area of
a damper in accordance with a progressive action slide assembly of
the invention; and
[0093] FIG. 57 is a perspective view of an elastomer friction
clutch seal of the damper of the invention.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0094] An improved fluid-flow damper 10 of the invention is
described herein by reference to each of FIGS. 2 through 57. The
damper 10 may be used with any gas-carrying ductwork 14A, 14B, and
is particularly applicable to heating, ventilation and air
conditioning (HVAC) systems of buildings and the like. The damper
structure may be varied so that the apparatus may be alternatively
used as:
[0095] 1. a volume damper,
[0096] 2. a tight seal damper,
[0097] 3. a smoke damper,
[0098] 4. a fire damper,
[0099] 5. a combination smoke and fire damper, and/or
[0100] 6. a motorized control damper combined with any of
selections 1 through 5, above.
[0101] The damper 10 is configured so that standard blades of a few
different sizes may be combined to accommodate a wide variety of
non-standard duct sizes.
[0102] The damper 10 has structure making it particularly adapted
for deterring the spread of fire and/or smoke in a conflagration,
e.g. through a fire resistant wall, a floor, or other barrier.
[0103] By reference to FIGS. 2 and 3, the damper 10 includes an
inner channel 13 defined by walls 12A, 12B, 12C and 12D. The damper
10 is shown with an inlet end 26 connected to an upstream duct 14A
for receiving an inlet gas stream 22. An outlet end 28 is connected
to a downstream duct 14B for discharge of an outlet gas stream 24.
Damper ends 26, 28 may comprise any type of useful duct connection,
and may be, for example, any standard duct flanges, or may comprise
"flush" joints which are bent to interlock with the ducts, both
types of connection being well known in the art.
[0104] The embodiment of damper 10 illustrated in FIG. 2 is
configured to pass through a barrier 16 such as a fire resistant
building wall or floor, for example, shown in hatched lines. A
fixed flange 36 of the damper 10 and an adjustably movable flange
38 abut opposite sides of barrier 16.
[0105] Within damper 10 is a damper closure 18 comprising one or
more flow control vanes or blades 20 as shown in FIG. 3. The
position of blades 20 is controlled between a fully open position
and a fully closed position by a drivetrain 30 including a
gearshaft 34 passing through walls 12A and 12B. Portions of the
drivetrain 30 are enclosed in one or both of first control
compartment 42 and second control compartment 44 which extend
outwardly from wall 12A and 12B, respectively, and are enclosed
with covers 46, 48. As shown in FIGS. 13 and 13A, each of covers
46, 48 may comprise two separate cover portions 46A, 46B, and 48A,
48B, respectively.
[0106] Returning to FIG. 2, gearshaft 34 may be rotatively actuated
manually, e.g. by an exposed hand lever or wheel, for example, or
other device. A simple manually controlled damper 10 will
preferably include a locking device to preset the control lever or
wheel in a desired constant-flow position. Such locks are well
known in the art.
[0107] Optionally, or in addition, a motorized positioner 32 may be
installed for automatic actuation of the closure 18. Positioner 32
may be connected to the gearshaft 34 where the shaft protrudes from
wall 12A and/or wall 12B, i.e. within a control compartment 42, 44,
or on the outside of cover 46 or 48. The positioner 32 may be
electrically controlled from a distant location if desired, to
continuously adjust the closure position in response to some input.
In addition, positioner 32 may be responsive to an emergency
situation.
[0108] Operation of the closure 18 is not dependent upon
gravitational force, so the damper 10 may be oriented in any
position as dictated by the particular application, i.e. for gas
flow in the horizontal, vertical, or sloping directions.
[0109] The drive train 30 includes (a) the gearshaft 34, (b) a gear
40 mounted on the gearshaft 34, (c) a slide assembly 50 having (d)
a toothed rack 62 driven by gear 40, and to which is attached (e) a
driven hinge pin 54B of (f) the closeable blade 20.
[0110] To further describe the drive train 30, and as shown
particularly in FIGS. 3, 4, 5 and 6, the closure 18 comprises one
or more parallel airfoil shape changing blades 20. Two blades 20
are shown in FIG. 3 in the open position. As further described in
the closed position in FIGS. 4 and 5, each blade 20 includes four
hinged panels 52A, 52B, 52C and 52D, each of which is connected by
hinge pins 54A, 54B, 54C and 54D at hinge joints 60A, 60B, 60C, 60D
along two opposing edges to two other panels. Thus, in
cross-section (FIGS. 5 and 9), the panels of blade 20 form a
four-sided polygon with straight or slightly outwardly arcuate
sides (i.e., panels 52A, 52B, 52C, 52D) of equal or nearly equal
length. The interpin distance 99 (see FIG. 5) between the
stationary hinge pin 54A and the driven hinge pin 54B is at a
minimum or near-minimum when the blade 20 is fully closed, and at a
maximum or near-maximum when the blade is fully open.
[0111] A stationary hinge pin 54A connects panels 52A and 52B along
stationary axis 76 and is mounted at one end through damper wall
12A and at the opposite end mounted through wall 12B. For the sake
of simplicity, the two panels 52A, 52B will be termed "front
panels" herein. Likewise, panels 52C and 52D will be termed "rear
panels". However, despite these titles, it is notable that damper
10 may be configured so that fluid flow is from either of damper
ends 26 or 28.
[0112] A driven hinge pin 54B connects panels 52C and 52D and has
one end projecting through a linear slot 56 in damper wall 12A into
the control compartment 42, where it is connected to a slide
assembly 50. See FIG. 3. Slide assembly 50 has a slot 58 through
which stationary hinge pin 54A passes; hinge pins 54A, 54B guide
the slide assembly in linear movement. Optionally, driven hinge pin
54B may also pass through a corresponding linear slot 58 in damper
wall 12B (compare FIGS. 3 and 13A). The slide assembly 50 includes
a rack 62 with gearteeth 64. Rotation of gear 40 on gearshaft 34 in
engagement with slide assembly 50 moves the slide assembly in a
linear direction, resulting in linear movement of the driven hinge
pin 54B to open or close the closure 18. The slide assembly 50 also
includes a linear guide slot 68. A guide pin 70 is mounted on wall
12A near the gear 40 to slide in slot 68. The guide pin 70 is a
stand-off device which guides the rack 62 of slide assembly 50 in
proper axial and radial aligned engagement with gear 40. The
lengths of rack 62, slot 68 and slots 56, 58 are determined by the
travel required to fully open and fully close the blade(s) 20.
[0113] As shown further in FIG. 4, a blade 20 (shown in the closed
position) also has two floating hinge pins 54C, 54D which connect
panel 52A to panel 52D, and panel 52B to panel 52C along parallel
axes 78, 78.
[0114] The hinge joints 60A, 60B, 60C and 60D may be formed by
notching each panel side 84A, 84B and bending the projecting
(unnotched) portions in a semicircle which will enclose the
appropriate hinge pin 54A, 54B, 54C or 54D. As shown in the
figures, the panels 52A, 52B, 52C, and 52D may be made to be
identical. Savings in time and expense will accrue, and the
resulting blade 20 is symmetrical, making installation virtually
foolproof.
[0115] Each panel 52A, 52B, 52C and 52D is formed of e.g. metal
plate of a thickness 82 which provides a very strong blade 20
wherein exascerbated duct pressures which may be encountered under
high stress conditions will not bend the panels or unfurl the hinge
joints 60A, 60B, 60C or 60D. Thus, for example, panels having a
drive pin travel 72 of about 5-12 inches may be formed of steel or
stainless steel having a thickness 82 of about {fraction (1/16)}
inch.
[0116] While the blade 20 as described above will, when closed,
permit only a small leakage of gas, the device may be enhanced by
the application of seals to further prevent gas flow through each
blade as well as in the interstices between the blade and the
damper walls and adjacent blades.
[0117] In a particular feature of the invention, the exterior of
each panel 52A, 52B, 52C, 52D is covered with one of seals
identified by numeral 80A, 80B, 80C and 80D in alternating or other
fashion. As depicted in FIGS. 4 through 8, a damper blade 20 (shown
in the closed position) comprises four panels 52A, 52B, 52C and
52D, hinged together by stationary hinge pin 54A, drive hinge pin
54B (directly behind pin 54A in FIG. 4) and floating hinge pins 54C
and 54D. The damper blade 20 is opened by moving the drive hinge
pin 54B in direction 88, normal to blade center plane (closed) 92
and parallel to blade center plane (open) 94. Thus, the blade 20
has a cross-sectional shape of a four-sided polyhedron with corner
angles 100 continuously changeable between a minimum greater than 0
degrees and a maximum less than 180 degrees. Preferably, corner
angles 100 vary from greater than about 10 degrees to less than
about 170 degrees. In a more preferred form, corner angles 100 vary
from about 10 to about 22 degrees in the fully closed position to
about 155 to about 168 degrees in the fully open position.
[0118] Seals 80A, 80B, 80C and 80D are formed of a thin flexible
material, such as a sheet of spring steel having a thickness 90 of
from about 0.004 inches to about 0.015 inches, for example.
[0119] Seals 80B and 80C are shown in FIG. 6 as having a generally
planar section 102 comprising the major portion thereof. A seal
wing 106 is formed by bending the seal 80B, 80C along line 110
parallel to first edge 104, at an angle 108 of about 30-55 degrees,
and preferably about 40 to about 50 degrees. Seal wing 106 has a
width 120 enabling its extension outwardly beyond the end of the
blade 20 to sealingly intercept a similar wing 106 of an adjacent
blade (FIG. 8), or to sealingly intercept the wall 12C or 12D of
the damper channel 13. In FIG. 8, a seal wing 106C of a seal 80C on
rear panel 52C interacts with a seal wing 106B of a seal 80B
mounted on front panel 52B.
[0120] If desired, the interacting seals 80A, 80B may alternatively
be both mounted on the front panels 52C, 52D, or alternatively on
both rear panels 52A, 52B. In these configurations, the outer edges
104 of the two interacting seal wings will abut each other instead
of meshing with each other.
[0121] Along second edge 114 opposite edge 104 may be formed a
narrow partial crimp 112 by bending along line 116 parallel to
second edge 114. Bending angle 118 may be any angle which will lift
the edge 114 slightly from the panel 52A, 52B, 52C or 52D to
utilize spring force of planar section 102 to ensure forcible
contact between crimp 112 and the panel. Angle 118 may thus be any
angle between 0 degrees and about 90 degrees, but preferably is on
the order of about 5 to about 25 degrees. The width 122 of partial
crimp 112 is configured to be sufficient to provide an adequate
sealing force and prevent leakage.
[0122] Seals 80A, 80D cooperate with seals 80B, 80D and are shown
in FIG. 7 as having a major planar section 102 and partial crimps
112 on opposing longitudinal edges 115. Seals 80A, 80D do not have
a seal wing 106 extending from the blade 20.
[0123] One of seals 80A, 80B, 80C or 80D is attached to the
exterior of each of blade panels 52A, 52B, 52C and 52D, typically
by spot welding, although other attachment methods may be used. In
a preferred embodiment, the attachment 126 is made within the
generally central portion of the panel, i.e. within a central
portion 128 comprising e.g. about 2/3 of the panel width 98 (see
FIG. 4). This permits the central portion 128 to exert a force
which retains the partial crimps 112 against the panels for proper
sealing.
[0124] The ends of blades 20 may be sealed against the walls 12A,
12B by end extensions of seals 80A, 80B, 80C and 80D, or by
separate seals 80E which seal only when the blades 20 are closed.
In FIGS. 13 and 13A, a seal 80E is depicted mounted on stationary
hinge pin 54A and biased against the blade 20 by contact with wall
12A. The seal 80E, formed of spring material like seals 80A, 80B,
80C and 80D has a cutout portion into which drive hinge pin 54B
will move when the blade is in the closed position.
[0125] It should be noted that the seals 80A, 80B, 80C, 80D and 80E
are required to be effective only when the blade(s) 20 of closure
18 are in the fully closed position A of FIGS. 5, 8, and 9. Thus,
when the blade 20 is in the closed position, partial crimps 112 of
adjacent seals 80A and 80B closely approach each other, and cover
the hinge slots 130. The same is true for adjacent seals 80C and
80D. For example, in a closed blade 20 having a panel width 98 of
about 2 to 8 inches, the separation distance 124 between adjacent
seals 80A and 80B may be typically less than about 1/8 inch and
occurs on the hinge itself, where tolerances are very tight. Thus,
very little if any leakage occurs between adjacent seals.
[0126] In FIG. 9, a blade 20 is depicted in the closed position A,
in a semi-open position B, and a fully open position C. To open the
blade 20, driven hinge pin 54B is moved along plane 132 by
drivetrain 30, previously summarized. Floating hinge pins 54C and
54D move along circular path 134 from blade center axis (closed) 92
to approach blade center axis (open) 94. The open flow area in the
damper 10 is determined as a function of blade width 132 passing
through pins 54C, 54D, or the angle 136 between panels 52A, 52B and
blade center axis (closed) 92, as shown by example in FIG. 10. It
may be noted that the major portion of the actuation distance
occurs at lower flows. Thus, for example, 60 percent of actuation
opens the closure 18 only about 20 percent of full flow. This
enables more precise flow control at the lower flow rates, where
control is generally more difficult.
[0127] Returning now to other portions of the drivetrain 30 shown
in FIG. 3, we see slide assembly 50 which is linearly moved in
direction 138 by gear 40, and in turn moves driven hinge pins 54B
in slots 56 in damper wall 12A to open and shut the damper blades
20. Slide assembly 50 may take any form attached to driven hinge
pins 54B and is shown as including a toothed rack 62, a slot 58 (at
least partially coextensive with slot 56) through which stationary
hinge pins 54A may slide, means such as guide slot 68 through which
guide pin 70 may slide for guiding slide member 50 in proper mesh
with gear 40, and biasing means such as spring 66 which biases the
slide assembly 50 to a default position, either closed or open.
Slot 58 in the slide assembly 50 is at least partially coextensive
with slot 56 in wall 12A when the slide assembly is in the open
position shown in FIG. 3.
[0128] In the particular embodiment of FIGS. 3 and 11, spring 66 is
attached to wall 12A by attachment 84, and to slide assembly 50 by
attachment 86, to motivate slide assembly 50 to a closed default
position, as shown. Thus, unless impeded by some other force (such
as by the gear 40), the slide assembly will default to the closed
position. It is further noted that should the spring 66 break or
stretch, upstream gas pressure from gas flow 22 will also tend to
close the blades 20 and maintain the blades closed. This "double
default" enhances the inherent safety of this damper 10. It is
evident that any pressure increase merely tightens the seal. In the
embodiment of FIG. 11, slots 56 in channel walls 12A, 12B lie
upstream of the stationary hinge pin 54A.
[0129] It is further noted that as shown in FIG. 13, attachment 84
may comprise a standoff which maintains the spring 66 generally
parallel to wall 12A. However, the standoff distance 85 may be
reduced to position the spring 66 close to wall 12A, thereby
reducing the required size of attachment 84.
[0130] It is mentioned above that the damper 10 is also
bidirectional with respect to fluid flow. Thus, the damper 10 shown
in the figures may be reversed in the duct system so that the inlet
fluid stream 22 tends to open, rather than close, the damper blades
20. This may be used when it is desired to have the damper 10
default to an open position should the spring 66 break or become
non-tensile due to high temperatures.
[0131] In another embodiment shown in FIG. 12, the damper 10 is
installed as shown, but the upstream hinge pin is configured as the
stationary pin 54A, i.e. it is mounted in channel walls 12A, 12B to
be stationary. The downstream hinge pin is configured as the driven
hinge pin 54B, and moves in linear slots 56 in the channel walls
12A, 12B. In this configuration, the drivetrain 30 moves the driven
hinge pin 54B upstream to close the damper blades 20, and slots 56
lie downstream of the stationary hinge pin 54A.
[0132] As shown in FIG. 12, the damper 10 is configured to be
"double defaulted" in the open position, in that the fluid flow 22
tends to open the blades 20, and the spring 66 does as well. The
upstream hinge pin of each blade 20 is installed as the stationary
pin 54A, and the downstream hinge pin is attached to the slide
assembly 50 and moveable thereby to open and close the blade.
Furthermore, the spring 66 is installed to motivate the slide
assembly 50 to the open position. Upstream pressure will open the
damper 10 should the spring 66 become ineffective. Thus, the damper
10 is fail-safe in the open position.
[0133] The direction of spring force in FIG. 12 may be reversed to
provide a spring default in the closed position.
[0134] Thus, it is evident that in the damper 10 of this invention,
the (a) position of the driven hinge, (b) spring force direction,
and (c) the direction of fluid flow may each be varied separately
to obtain a variety of configurations for different
applications.
[0135] The slide assembly 50 may be formed as a singular member, as
by molding, for example. It may also be formed from commonly
available materials such as sheet metal, metal plate, a geared
rack, etc, which may be joined as by welding or with fasteners, not
shown, or joined by the hinge pins 54A and/or 54B themselves. By
comparing the cross-sectional view of FIG. 13 with FIG. 3, it is
seen that slide assembly 50 may comprise a rack tee 50A and a
linkage plate 50B. Driven hinge pin 54B is connected to the rack
tee 50A and slides in linear slot 56 in damper wall 12A. The rack
tee 50A has a toothed rack 62 of gear teeth 64 which communicate
with teeth 41 of gear 40, the latter rotatable by gear shaft 34
about shaft rotation axis 33. The rack tee 50A is also guided by a
guide pin 70 which may be a standoff mounted to wall 12A by a rivet
146 and washer 148 to maintain a desired distance 150 between the
wall 12A and the rack tee. Guide pin 70 slides in guide slot 68 in
the rack tee 50A and is located proximate the gear 40 in order to
maintain proper contact therebetween, and to guide the rack tee 50A
in a straight line.
[0136] The linkage plate 50B is shown as being generally parallel
to the rack tee 50A and spaced therefrom by spacer washers 152
about hinge pins 54A and 54B. Stationary hinge pin 54A slides in
slot 58 in the linkage plate 50B. Both hinge pins 54A, 54B are
positioned axially to the slide assembly 50 by e.g. push nuts 154.
Spacer washers 152 also separate the linkage plate 50B and the
blade(s) 20 from the inner wall 12A.
[0137] With reference to FIGS. 13 and 14, the damper 10 may be used
as a simple volume damper, tight seal damper or electronically
actuated smoke damper, in which the damper 10 uses a gear 40 which
is fixed to shaft 34. Gear shaft 34 may itself extend across the
inner channel 13 to be rotatably mounted in a bearing 96.
Alternatively, the gear shaft 34 may be mounted on a continuation
shaft 74 which generally spans the inner channel 13, as depicted in
the figures. The gear shaft 34 may be rotated by handwheel or
lever, or by a powered positioner 32. Inasmuch as the rotational
forces exerted on continuation shaft 74 are minimal, the diameter
180A thereof may be substantially less than the diameter 180B of
gear shaft 34. Thus, the resistance to gas flow in the damper
channel 13 is reduced.
[0138] For use as a fire damper or combination fire/smoke damper,
the damper 10 has means for defaulting the closure 18 to either a
predetermined fully closed or fully open position, irrespective of
the gear position. Thus, in a fire, the closure 18 will close or
open to the predetermined default condition in the presence of
heat, even in the absence of electrical power. Apparatus for
enabling improved use as a fire or fire/smoke damper will be
described in reference to FIGS. 3 and 13 through 22.
[0139] As shown in FIGS. 15-19, gear shaft 34 extends from an outer
end 184 through an opening 166 in wall 12A to an inner end 182.
Shaft 34 has a flange 162 which rotatably abuts the outside of wall
12A, and an outer groove 178 in which a lock ring 156 may be
installed to rotatably abut the inside of wall 12A. The inner end
182 of shaft 34 has a hollow space 186 into which continuation
shaft 74 may be coaxially seated and fixed, e.g. with setscrew 164.
A hollow space 188 extends inwardly from the outer end 184 of shaft
34. The end portion 192 of continuation shaft 74 has a slanted slot
194 through which disconnect cable 142 may pass. The cable further
passes through a restricted hole 196 in shaft 34 into hollow space
188 and is fixed in a spring-biased cog 170. The gear 40 is
configured to rotate freely about gear shaft 34 when the cog 170 is
in the disconnected position shown in FIG. 15. It is axially held
in place by a retainer pin 160 which passes radially through shaft
34 and abuts a spacer washer 158 mounted on shaft 34 to retain the
gear 40 in place. The retainer pin 160 also acts as an outer limit
to axial movement of the cog 170.
[0140] As depicted in FIG. 15 through 22, cog 170 comprises an
elongate cog body 172 movable along axis 33 within shaft chamber,
i.e. hollow space 188 of gear shaft 34. The cog 170 includes
crosspiece fingers 174 which radially project through opposed slots
177 in gear shaft 34 and into a divided chamber 190 radially
outside of shaft passageway 35 in gear 40. The divided chamber 190
has an outer circular chamber 190A and one or more slot chambers
190B which extend inwardly from chamber 190A. The slot chambers
190B are large enough to each hold a crosspiece finger 174 in a
relatively fixed position. Thus, when the fingers 174 are seated in
slot chambers 190B, the gear 40 is motively connected to shaft 34.
When the fingers 174 are in the outer circular chamber 190A,
rotation of shaft 34 merely rotates the fingers in chamber 190A
without moving the gear 40. As shown, the cog 170 is biased by
spring 168 so that, without an opposite motivating force, the
crosspiece fingers 174 are retained in a disconnected position
relative to the gear 40.
[0141] As depicted in FIG. 3, a fusible link 140 is connected by
cable 142 to the cog 170 (see FIGS. 15, 22) by welding, for
example, and to a screw or other attachment means 141 on the
continuation shaft 74 (see also FIG. 13A), so that shafts 34 and
74, fusible link 140 and cable 142 rotate in common. As shown in
FIG. 22, moving cable 142 in direction 198 and affixing it to
maintain crosspiece fingers 174 seated in slot chambers 190B
results in a drive train 30 which is motivated by rotation of gear
shaft 34. Fusible links 140 as known in the art are used to
disconnect apparatus in a range of preset temperatures. When a
fusible link 140 is melted, it releases the disconnect cable 142
allowing spring 168 to disengage fingers 174 from the slot chambers
190B.
[0142] Thus, for example, a fusible link 140 which melts at 135
degrees F. will disconnect the gear 40 from the gear shaft 34, and
may be used to automatically fully shut (or optionally fully open)
the spring-biased blades 20 at that temperature, overriding the
gear setting and independent of possible electrical power loss.
[0143] In a broad sense of the invention, the default position of
the blades 20 need not be just "fully closed" or "fully open" but
in fact may be any intermediate position as well, by limiting the
drive pin travel 72 under disengagement conditions. This may be
easily accomplished by limiting the lengths of slots 56, 58.
[0144] As shown in the views of FIGS. 3, 13 and 13A, the slide
assembly 50, gear 40, and spring 66 are all within the first
control compartment 42. These parts of the drivetrain 30 may
alternatively be installed (as a mirror image) in the second
control compartment 44 on the opposite side of the damper channel
13. In use, compartments 42 and 44 have covers 46, 48, respectively
(see also FIG. 2). In one form of the invention, covers 46 and/or
48 may be subdivided into several cover portions, e.g. 46A, 46B or
48A, 48B. Thus, for example, the portions of compartments 42 and 44
installed within a fireproof barrier 16 may have fixed covers 46A,
48A and the remainders of the compartments have covers 46B, 48B
which are removable for access. FIG. 13 shows a fixed cover 46A
attached by screws 144 and with an intervening gasket 145; an
exemplary removable cover 46B is also shown. A wide variety of
cover configurations may be used. Typically, gear shaft 34 passes
through the cover 46 or 48 for external manual or powered
actuation.
[0145] FIG. 13A shows a fixed cover 48A and a removable cover 48B.
Stationary hinge pin 54A is fixedly mounted in wall 12B and driven
hinge pin 54B is movably mounted in linear slot 56 in wall 12B. The
continuation shaft 74 is shown as passing through a bearing 96 in
hole 185 in wall 12B and further through a hole 187 in cover 48B.
However, the shaft 74 may be terminated in bearing 96 or in
compartment 44 if there is no need for rotating the shaft from its
end 193.
[0146] The damper 10 of the present invention provides important
advantages in the art, in that it enables a wide variety of
configurations with minimal changes. The damper is constructed to
take advantage of a four-panel quadri-hinge blade with panels of
generally the same width. While the upstream panels may have a
slightly different panel width 98 than the downstream panels, a
difference greater than a few percent may compromise damper
operation. The drive train 30 is generally narrow, taking up
minimal space. The motorized positioner 32 or manual control
actuator may be positioned on either side of the inner channel 13.
The damper does not depend upon gravity for its action, nor is its
operation hampered by mounting in any particular position.
Furthermore, the damper is bi-directional to expand the options for
particular applications.
[0147] Turning now to other variants of the invention, a
self-locking damper blade configuration is shown in FIGS. 23 and
24. As shown in FIG. 23, when damper blades 20 are in a closed
position denoted by the numeral 230, the angle 55 between panels
52C and 52D is less than 180 degrees by a margin of up to about 15
degrees or more. Preferably, angle 55 is about 4-10 degrees. In
other words, movable hinge pin 54B lies inside of the line between
the floating hinge pins 54C and 54D, being enabled by the drive pin
slot 56 in the damper wall and the travel of the rack tee 50A (not
shown). As shown, panels 52C and 52D are preferably slightly
shorter than panels 52A and 52B.
[0148] In this embodiment, an inlet fluid stream 22 will maintain
the blade 20 in a closed position 230. Furthermore, an increase in
downstream pressure by fluid stream 23 in the opposite direction
will also act to maintain a closed blade 20, inasmuch as pressure
on panels 52A and 52B by stream 23 will result in compressive force
on panels 52C, 52D to maintain drive pin 54B in the fully closed
position. Actuation of the drive pin 54B by the slide assembly 50
(shown in other views) is required to unlock the closed blade 20,
moving it toward an open position 232. As already depicted in FIG.
11, a spring 66 will move the slide assembly 50 together with
blades 20 to a default closed position 230, or alternatively, to a
default open position 232, in the event of fire or high gas
temperature, or other event which disengages the drive motor from
the slide assembly.
[0149] Also shown in FIG. 23 are blade seals 80B which block off
the space between adjacent blades 20. Each blade seal 80A, 80B is
attached to or is an extension of a panel 52 adjacent one of the
floating hinge pins 54A, 54D. The blade seal 80B is preferably
formed of a thin layer of flexible material such as spring steel
having sufficient strength to resist possible high pressures within
the damper 10.
[0150] As depicted in FIG. 24, the blade seal 80B is preferably
formed with at least one, and preferably two folds or bends 100A,
100B, and is configured to approach, contact and compressively seal
against the opposite side of the next blade 20. Thus, a seal 80B
mounted on an upstream panel 52D will compressively seal against
downstream panel 52A of another blade 20.
[0151] As shown in FIG. 25, when the blade 20 is moving to an open
position 232, the seals 80B are compressed by blade movement from a
non-compressed state shown by a hatched line to a compressed state.
The compression is in the opposite direction from the blade closing
action shown in FIG. 24.
[0152] While each seal 80B may extend across an entire blade 20,
more balanced seal forces result from splitting the seal along an
opening between blades, such as shown in FIG. 25. In this example,
a portion of an opening between blades is spanned by one seal 80B
attached to panel of the lower blade 20A, and the remaining portion
is sealed by a second seal attached to panel of the upper blade
20B. As a drive pin 54B is moved in direction 109, the interpin
distance 59 between "stationary" pins 54A is narrowed. A first seal
80B mounted on panel 52D of the lower blade 20A becomes
compressingly sealed against panel 52a of upper blade 20B.
Likewise, a second seal 80B mounted on panel 52C of the upper blade
20B becomes sealed against panel 52B of the lower blade 20A. Seals
80B between blades and interior damper walls 12 may be mounted
similarly.
[0153] In another damper apparatus of this invention, illustrated
in FIGS. 29, 30, 31, 32, 33, 34, 35, 36 and 36A, a disengagement
apparatus 228 links a motor shaft 242 to a gear 40 driving the
slide assembly 50. Disengagement apparatus 228 includes a hollow
gear shaft 234 with a first end 238, a second end 240 and an
intermediate stop flange 162. A hub 236 has an axial portion 254
and a radial portion 256, and is configured to be rotatably mounted
on the gear shaft 234. The hub 236 is configured for attachment of
a gear 40 to the radial portion 256. The gear shaft has a
circumferential cog opening 258 which may be rotatably positioned
in line with cog opening 260 in the hub 236. As shown in FIG. 34,
cog opening 258 has a circumferential angle 274 which is sufficient
to hold a pivoting cog 246 and permit it to move from an engagement
position to a disengagement position. For example, in a typical
disengagement apparatus, the radial angle 274 may generally be
about 100-130 degrees. However, angle 274 may be greater, or less
than this range.
[0154] As shown in FIGS. 29 and 34-36, a cog 246 is shown as
generally having a radius arm shape. In an engaged position, the
cog 246 passes outwardly through cog opening 258 to releasably
engage opening 260 in the hub 236 so that rotation of the gear
shaft 234 drives the hub 236 and attached gear 40. The cog 246 is
rotatably mounted on an axial cog pin 252 in a hole in the gear
shaft 234. When a movement-limiting key surface 264 is removed, the
cog 246 pivots inwardly under the force of rotation of a rotating
hub portion 254. The hub portion 254 slides over the cog, forcing
it inwardly to a disengagement position. This is a fail-safe
feature of this disengagement apparatus 228.
[0155] A key 250 formed of a plate material is slidably mounted in
the gear shaft 234. The key has a head 250A which slides in opposed
axial slots 268 in the gear shaft 234. The key 250 is spring
mounted so that when resistance to movement of the key (via
disconnect cable 142) is released, spring 168 pushes the key from a
position in which the cog 246 is engaged by key surface 264 (FIGS.
29 and 34) to a position in which the cog is disengaged, i.e. the
cog rotates to key surface 266 shown in FIGS. 35 and 36. The hub
236 and attached gear 40 then may rotate in direction 270
independent of the gear shaft 234, whereby the damper 10 may move
to a designated fail-safe position.
[0156] As depicted in FIG. 29, a motor shaft 242 is retained in the
first (i.e. exterior) end 238 by a pin 272 for example.
Continuation shaft 74 is fixedly mounted in the second (i.e.
interior) end 240. The gear shaft 234 is shown as passing through a
channel wall 12A, and is held between the stop flange 162 and a
retainer ring 156 mounted in a circumferential slot 178 in the gear
shaft. In these figures, the gear 40 is shown attached to the
wall-facing (i.e. interior) side 244 of the hub 236. However, in
most cases it will be attached to the exterior side 248, in which
case the cog opening 260 will be largely covered by the gear 40,
and protected thereby.
[0157] Several versions of a drivetrain 30 are based on a somewhat
different cylindrical gear shaft 234 shown in FIG. 27. The gear
shaft 234 is depicted with a first (exterior) end 238, second
(interior) end 240, and intermediate stop flange 162. The gear
shaft 234 is generally hollow, and has an interior portion 278 with
reduced diameter (see FIG. 37). As shown, a cog opening 258 is cut
through about 100-120 degrees of the shaft 234 on the exterior side
of the stop flange 162, and spaced therefrom. A set of cog pin
slots 262 axially extending from each side of the cog opening 258
are configured to retain a rotatable cog pin 252 (see FIG. 37).
This permits rotation of a mounted hub 236 in direction 270, i.e.
right-hand rotation, to move a cog 246 downward to a disengagement
position when a key is released. A second set of cog pin slots 262A
enables disengagement rotation in the opposite, i.e. left-hand
direction 270A if the drivetrain 30 is so configured. A gear shaft
234 having both sets of cog pin slots 262, 262A may be selectively
used for either configuration, merely by reversing the cog
orientation in the opening 258.
[0158] Gear shaft 234 is also shown with a circumferential slot or
groove 178 in which a retainer ring 158 may be inserted to hold a
sheet metal wall against the stop flange 162. Fastener holes 164A
are shown for retaining a motor shaft 242 and a continuation shaft
74 by fasteners, e.g. screws.
[0159] FIG. 28 depicts a hub 236 which is mounted from the first
end 238 of the shaft member 234 to generally abut hub stop flange
162. The hub 236 has an inside bore 284 and is configured to rotate
about the shaft member 234, i.e. about central axis 33. The hub 236
has an axial portion 254 with a cog opening 260, and a radial
portion 256 to which a gear may be fixed by e.g. screw holes 276.
Selective positioning of a cog 246 within the cog opening 260
engages and prevents rotation of the hub 236 relative to the shaft
member 234. Gears 40 of varying sizes may be attached to the radial
portion 256 of hub 236, limiting the number of hub sizes required
by an HVAC business to accommodate a wide range of damper
sizes.
[0160] An exemplary disengagement apparatus 228 comprising the gear
shaft 234 and hub 236 is depicted in FIGS. 37 through 43. In FIGS.
37 and 38, the hub 236 is shown as being retained on the gear shaft
234 by a retainer ring or bushing 282. The shaft member 234 is
shown with a radial opening 244 through which a controllable cog
246 may be projected into an opening 248 in the hub 236, engaging
the hub to the shaft member for simultaneous rotation. The cog 246
is shown in FIG. 37 in an engaged position. As already described
relative to FIGS. 13 and 13A, in the event of a fire or high
temperature, a thermal fuse connected to disconnect cable 142 will
melt, releasing the disconnect cable. In FIG. 38, movement of a
spring-biased key 250 by release of disconnect cable 142 permits
the cog 246 to swivel inward due to downstream biasing spring
forces (from spring 66) which rotate the gear 40 and hub 236. The
cog 246 swivels in a radial plane (relative to central axis 33) to
a disengagement position, i.e. outside of cog opening 260. Thus, in
FIG. 38, hub 236 and attached gear 40 may freely rotate about the
shaft member 234 free of restraining force from the motor shaft
242.
[0161] The key 260 of this embodiment is depicted in FIGS. 39-43.
The key 250 is an elongate device which is concentric about a
central axis 33 and has a central longitudinal borehole 292
beginning at a first end 286. A spring 168 (not shown) may be
mounted on the first end 286. The key has a second end 288 in which
is an aglet hole 298. An intermediate borehole 294 is also shown.
The exterior surface of the key 250 includes an engagement surface
264, a disengagement surface 266, and an intermediate surface 296
connecting the two. As depicted in FIG. 43, a disconnect cable 142
is passed through the borehole 292 and retained therein by aglet
300 fixed to the cable.
[0162] A further embodiment of a disengagement apparatus 228 is
shown in FIGS. 44, 45, 46 and 47. In this version, the gear shaft
234 is varied by adding an opening 306 opposite the cog opening
258. Opening 306 accommodates a key 250 whose first end 314 is
mounted on, and pivots about, a cross pivot pin 310. The cog key
250 is shown with a general inverted U-shape as viewed axially. The
key has two parallel legs 320 joined at the second end 316 by a
cross-piece 322 having the two exposed surfaces, i.e. engagement
surface 264 and disengagement surface 266. Surfaces 264 and 266
limit inward movement of a cog 246 in an engagement position and a
disengagement position, respectively. Surface 266 is oblique
relative to the engagement surface 264, generally being at an angle
therefrom of about 35-45 degrees. The configuration of the shaft
234 and key 250 limit the inward movement of the cog key 250 when
the disconnect cable 142 is under tension. From the engagement
position shown in FIG. 44, the key 250 may pivot in only one
direction, i.e. toward the first end 238 of the shaft 234. The cog
key 250 includes a transverse key pin 308 to which the disconnect
cable 142 and spring 168 are attached. When tension in the
disconnect cable 142 is released by melting of the attached thermal
fuse (see FIG. 13A), spring 168 will motivate the key 250 to pivot
to a disengagement position, allowing the cog to swivel inward out
of the cog opening 260 in the hub. Opening 306 limits the swivel
angle so that the key 250 will not go beyond the specified
disengagement position, where the disengagement surface 266 limits
further cog movement.
[0163] In FIG. 44, the spring has one end fixed to cross-pin 318
near the gear shaft's first end 238. The cross-pin will draw the
key 250 from its engagement position upon release of tension in
cable 142.
[0164] A hub retainer ring or bushing 282 is shown in FIGS. 44 and
45, and is used to retain rotatable hub 236 in place, as is shown
in the embodiment of FIGS. 37 and 38.
[0165] Turning now to FIG. 47A, another modification to the gear
shaft 234 is shown, i.e. forming a region 324 with a bore 280A of
reduced diameter, adjacent the cog key 250. This region 324 ensures
that the cog key 250 may pivot in only one direction from the
engagement position.
[0166] In each of the described versions of the disengagement
apparatus 228, the cog 246 is shown as having a shape generally
appearing as an arcuate stem 302 attached to an arcuate body 304 of
a circle or compressed circle. The cog 246 swivels about the cog
pin 252 which passes through the stem 302. This shape is shown in
FIGS. 45 and 47, for example, and is a preferred design, inasmuch
as the cog has sufficient area to provide strength, the required
area of opening 258 is minimized, and the cog will fully swivel
from an engaged position to a disengaged position. Furthermore,
when the cog key 250 is activated to disengage the cog 246, the
edge of opening 260 will contact a sloping i.e. rounded edge of the
cog to enable slippage thereon as it pivots the cog inward. This
positive movement is a "fail-safe" factor.
[0167] Some dampers are not intended as fire-safe but are merely
for controlling airflow at desired flowrates, i.e. "volume
dampers". Thus, a gear shaft and hub as previously described are
combined in a unitary "fixed hub" device 330 which is
interchangeable with the various embodiments of disengagement
apparatus 228, without the disengagement feature. As shown in FIGS.
48-51, a fixed hub device 330 includes a hollow shaft 332 with a
radial flange 334 mounted thereon. A first end 336 of shaft 332
includes a socket 176A into which a motor or controller shaft 242
is installed and fixed for example by a set screw 340 in screw hole
344. Likewise, a second end 338 of the shaft includes a socket 176B
into which a continuation shaft 74 is fixed for example by set
screw 340 in screw hole 346. The shaft 332 may have a uniform
diameter, or may have various diameters over its length if desired.
In these figures, the shaft is shown as having a reduced diameter
portion 346 adjacent the first end 336. A gear 40 may be attached
to the radial flange 334, using screw fasteners 340 in screw holes
348. The fixed hub device 330 may be rotatably attached to a wall
12A with a retainer ring 156 in an outer ring groove 178.
[0168] In another feature of the invention, the closure 18 may be
configured to use damper blades 20 of differing panel sizes. Such
blades 20 will of course have differing values of maximum closure
length. Thus, the distance the rack tee must be closed will vary
from blade to blade, and some blades will always remain partially
open (partially closed). In the feature depicted in FIGS. 52
through 55, a progressive action rack tee 350 is depicted as it
progressively moves in direction 354 to close a closure 18 from a
fully open position (FIG. 52) to a fully closed position (FIG. 55).
In this example, four blades 20C, 20D, 20E and 20F have closing
spans 352C, 352D, 352E and 352F of 12, 10, 8, and 6 inches
respectively, for a total span of 36 inches between damper walls
12C and 12D. Thus, they are spaced so that when all blades are in
the closed position, the damper is fully closed. As shown, each
blade has a fixed hinge pin 54A and a driven hinge pin 54B. The
fixed hinge pins 54 are shown as arrayed in a straight line across
the flow channel. The driven hinge pin 54B of blade 20C is fixedly
mounted in the rack tee 350. The driven hinge pin 54B of each
shorter blade 20D, 20E and 20F is mounted in a linear slot 356D,
356E and 356F, respectively to be moved by the slot ends.
[0169] In FIGS. 52-55, the driven hinge pins 54B are moved by the
rack tee 350 to the left to progressively shut the damper, and to
the right to progressively open the damper. In this example, driven
hinge pins 54B of blades 20D, 20E and 20F will be at the left end
372 of the slots 356D, 356E and 356F when the damper is fully open,
and at the right end 374 of the slots when the damper is fully
closed.
[0170] A slot seal member 360 shown in FIG. 57 may be used in
conjunction with the progressive action rack tee 350 to achieve
particular relationships of Percent OF Full Open (POFO) versus
Percent Actuation of the rack tee. As shown in FIG. 57, a driven
hinge pin 34B passes through a slot in a wall 358, and passes
through a slot seal member 360 which simultaneously (a) exerts a
clutch force on the hinge pin which must be overcome to achieve
movement of the pin, and (b) effectively seals the slot from
leakage. In accordance with the invention, the slot seal member 360
may be applied over a slot 56 of an inner channel wall (see FIG.
11), or over a slot 356D, 356E, or 356F in rack tee 350. In either
case, the slot
[0171] The slot seal member 360 is formed of a flexible material
such as an elastomer or an elastomer coated fabric. As shown, a
linear slit 362 is cut between two spaced-apart punch-holes 364.
The slot seal member 360 may be joined by e.g. cement 366 over a
slot 56 in a wall 358. Each punch-hole 364 is positioned and
attached over an end of a slot 56, 356D, 356E, or 356F, whereby the
hinge pin 34B slides within slit 362 and the punch-holes 364. The
punch-holes tend to retain the hinge pin 34B within the slot ends
372 and 374, providing a resistance to movement. The slit 362
provides resistance to movement, so that unless overcome by a
greater force, the slit will hold the hinge pin 34B in a given
position in the slot. The resistance to pin movement in the slit
362 may be controlled by varying the type of material, thickness of
the seal member 360, and width of the slit relative to the hinge
pin diameter.
[0172] The rack tee 350 is typically exterior of a damper wall 56
or 356. The driven hinge pins 34B pass through the damper wall,
i.e. through slots 56, as well as through slots 356 in the rack tee
350. The slot seal members 360 may be used in several different
ways by application to slots 56 and/or slots 356.
[0173] In a first embodiment, seen in FIGS. 52-55, seal members 360
are placed over slots 56 in the damper wall 12A but not over slots
356 in the rack tee 350. In this version, a driven hinge pin 54B
will begin moving toward the closed position only when it engages
the second end of the particular slot 356 in the rack tee. The
hinge pins 54B for blades 20D, 20E and 20F will sequentially engage
the slot ends 374, all attaining the fully closed position
simultaneously. The resulting closing curve 370A for this version
is shown in FIG. 56, together with a resulting opening curve 370B.
It is noted that these curves 370A, 370B are exponential in nature.
The start of a closing motion, or the start of an opening motion,
is very gradual. Unlike the use of equal blade lengths and
simultaneous equal closing (shown in FIG. 10), two different curves
370A, 370B are followed.
[0174] In another embodiment, the seal members 360 may be applied
to the rack tee slots 356D, 356E and 356F. In this case, the
opening and closing curves will differ in that they will be less
gradual at initial opening or closing. In any case, the curves
370A, 370B will vary depending upon the numbers and sizes of blades
20 and where the seal members 360 are applied.
[0175] It should be noted that seal members 360 may be placed on
slots 56 of the flow channel wall 12A as well as on the rack tee
slots 356D, 356E, and 356F. In this case, seal members 360A on the
channel wall 12A may be formed to provide greater resistance that
the seal members 360B on the rack tee 350, or vice versa. In this
way, for example, the channel wall slits may be sealed while the
rack tee seals control driven pin movement.
[0176] While a number of different embodiments are described in
this application, it is contemplated that other variations may be
made to the invention without significantly changing its
performance; such fall within the purview of the invention.
[0177] Thus, it is apparent to those skilled in the art that
further additional changes, additions and modifications may be made
in the improved damper apparatus as disclosed herein without
departing from the spirit and scope of the invention as defined in
the following claims.
* * * * *