[0001] This invention generally relates to an edgewise profiled, quadrilateral plate member
to be used as a wall member in a hollow wing-shaped profile, in particular a damper
blade, a guide blade or a vane.
[0002] In particular, the invention relates to the use of such a hollow profile as a damper
blade for a ventilation damper assembly of the type in which a number of substantially
rectangular damper blades of wing-shaped cross-sectional profile is pivotally suspended
with parallel axes of rotation between opposite frame members in a substantially rectangular
damper frame for mounting in an apparatus cabinet, in a ventilation duct or in a wall
opening, so that the damper blades can be moved between a closing position and an
opening position by rotation about said axes.
[0003] Ventilation damper assemblies of this kind are mainly used as air volume control
and damping means as well as mixing dampers when mounted in ventilation ducts of rectangular
cross-section, in wall openings or in apparatus cabinets, for instance for an air
conditioning central unit in an air conditioning system. Beyond a reliable closing
function with respect to sealing and a movement of the damper blades, which as far
as possible is free from noise and play, importance is attached to a simple and sturdy
design of the damper construction with the lowest possible costs of production for
the individual components thereof.
[0004] In a damper assembly disclosed in German Offenlegungsschrift No. 2,342,531 each damper
blade is composed of two opposite, plate members profiled into a wing-shaped cross-section
and being held together by longitudinal nose strips carrying longitudinal lobe seals
at the edges of the damper blade, together with an internal clamping thread.
[0005] For a similar construction of a damper blade composed of two plate members it is
moreover known from German Offenlegungsschrift No. 2,208,259 to join plate members
together by folding along the lateral edges without any need for additional connection
means for keeping the plate members together. The folding used in this case does not
allow any arrangement of sealing strips.
[0006] By the present invention a simple design of a hollow wing-shaped profile of the kind
used in such damper blades is obtained together with the possibility of arranging
and fastening a lobe seal directly in the joint between the lateral edges, by forming
the plate member into a wing-shaped cross-sectional profile by longitudinal rolling
and/or bending, and by forming along one of its opposite longitudinal edges of the
plate member a first edge portion having an edge flange bent once into substantially
U-shaped cross-section and at the other of said longitudinal edges a second edge portion
having an edge flange bent by two successive, oppositely directed bendings into a
substantially S-shaped cross-section for engagement with said first edge portion of
the same plate member or of another opposed plate member by pressing the extreme portion
of the edge flange of said second edge portion into the opening behind the edge flange
of the first edge portion, said edge flanges being locked in said engagement by end
members fitting into the internal cross-section of said hollow profile.
[0007] In accordance therewith, according to the invention, a damper blade of the above
mentioned kind is characterized in that a wall member of the damper blade is made
from a rectangular plate member by longitudinal rolling and/or bending into said wing-shaped
cross-sectional profile, said plate member being formed along one of its opposite
longitudinal edges with a first edge portion having an edge flange bent once into
a substantially U-shaped cross-section and at the other of said longitudinal edges
a second edge portion with an edge flange bent by two successive, oppositely directed
bendings into a substantially S-shaped cross-section, said first and second edge portions
of the same wall member or of two different, opposed wall members being put into engagement
with each other by pressing the extreme portion of the edge flange of said second
edge portion into the opening behind the edge flange of said first edge portion and
being locked in said engagement by end members fitting into the internal cross-section
of the damper blade to receive the rotational shaft or journals of the damper blade.
[0008] Thereby, by one and the same design of said edge portions of the plate member a damper
blade may be produced consisting either of a single wall member or being made into
double width by joining together two opposed wall members, each of the two edge portions
of one wall member being in engagement with the respective opposite edge portion of
the other wall member.
[0009] In a damper blade according to the invention a sealing strip may be fastened without
the use of particular connection means, in that a sealing member is arranged as a
lobe seal between the sides of said first and second edge portions facing each other
and is clamped by their mutual engagement. A simple ribbon-or strip-shaped member
may be used for sealing members, for instance made from rubber with a mainly flat
rectangular cross-sectional profile, so that there is no need for an expensive special
design of the sealing member. In a damper blade composed of two wall members sealing
strips may be arranged optionally at one or both longitudinal edges of the damper
blade.
[0010] However, the invention is not restricted to the production of damper blades of the
above mentioned kind, but it may generally find application in the production of hollow
profiles having walls made from sheet metal, for instance plate wings for axial flow
fans or profiled guide vanes or blades for centrifugal fans.
[0011] In the following the invention is explained in more detail with reference to the
schematical drawings, in which
Figs 1 and 2 illustrate a damper of the above mentioned type as an embodiment of the
invention, in a view perpendicular to the flow passage area and a perspective view,
resp.,
Fig. 3 is a cross-sectional view of a first embodiment of a damper blade according
to the invention,
Figs 4 and 5 illustrate two longitudinal sectional views at right angles to each other
of the portion of the damper blade engaging a frame member in the damper frame, and
Fig. 6 a cross-sectional view of another embodiment of the damper blade.
[0012] The damper assembly shown in Figs 1 and 2 is mounted in a rectangular, in the present
case almost quadrilateral damper frame comprising frame members 1 to 4 made from bent
sheet profiles of a substantially flat, U-shaped cross-section, so that either frame
member as shown at 5 and 6 for the frame member 1 is provided with edge flanges to
secure the damper frame either to a ventilation duct having the same flow passage
area and cross-sectional shape or to a wall opening or an opening in the side or end
wall of an apparatus cabinet, for instance for a central unit in an air conditioning
system in which one or more fans, air humidifiers, filters and/or heating members
may be arranged.
[0013] In the illustrated embodiment four damper blades 7 to 10 of wing-shaped cross-sectional
profile are.rotatably suspended in the damper frame with parallel axes of rotation
between two opposite lateral frame members 1 and 3, an end member 11 being provided
at either end of each damper blade as shown in Figs 4 and 5 and comprising a journal
12 positioned with sliding fit in a bushing 13 drawn up in the sheet member of the
frame member.
[0014] In Figs 1 and 2 the damper blades 7 to 10 are shown in a central position between
a closing position in which the damper blades extend transverse to the flow direction
and block the flow passage area, and an opening position in which the damper blades
7 to 10 are substantially parallel to the flow direction.
[0015] The operation of the damper blades is effected by means of an arm 14 secured to the
journal 12 for one of the damper blades 7, and the damper blades 7 to 10 are interconnected
with respect to movability through a drive mechanism including a coupling bar 15,
a pivot arm 16 positioned behind the coupling bar 15 being rotatably connected with
the coupling bar 15 and secured to one of the journals for each damper blade.
[0016] In Fig. 3 the cross-sectional profile of a first embodiment of a damper blade according
to the invention is shown. In this embodiment the damper blade is made up of a single
wall member 17 from sheet metal, said member having been formed into the wing-shaped
cross-sectional profile illustrated in the figure by longitudinal rolling through
a series of roller stations. As explained in the following the profile shape may further
be performed by a combination of longitudinal rolling and subsequent bending.
[0017] In accordance with the invention the wall member 17 is formed at one longitudinal
edge with a first edge portion 18 having an edge flange 19 bent once towards the interior
of the damper blade, so that the edge portion 18 obtains a substantially U-shaped
cross-section with its opening facing the interior of the damper blade.
[0018] For engagement with the first edge portion 18 the damper blade is formed at its other
longitudinal edge with a second edge portion 20 having an edge flange 21 bent towards
the interior of the damper blade so as to obtain a substantially S-shaped cross-section.
[0019] The shaping of the edge portions 18 and 20 with the flanges 19 and 21 into the illustrated
cross -sectional shape and the forming of slight, longitudinal bendings in the wall
member as shown at 22 and 23 to obtain the desired wing-shaped cross-sectional profile
as well as bending or folding as shown at 24 can be carried out in one and the same
rolling operation so that the edge portions 18 and 20 will be positioned opposite
each other. After the arrangement of a sealing member 25, which may be made, for instance
as shown by a ribbon- or strip-shaped member of rubber of substantially flat or rectangular
cross-sectional profile as a lobe seal between two sides of the edge flanges 19 and
21 facing each other, the edge portions 18 and 20 are put into engagement with each
other by squeezing them together by an external pressure against the sides of the
profile. As the plate member having edge flanges due to the profile shape produced
as mentioned has a certain spring action, the said squeezing causes the extreme portion
21a of the edge flange 21 to be pressed over the free edge of the edge flange 19.
By subsequently releasing the external pressure the extreme portion 21a of the edge
flange 21 will be pressed against the bottom of the U-shaped cross-section of the
edge portion 18 due to the spring action with its free edge in engagement with the
wall member opposite the edge flange 19.
[0020] In order to maintain the locking engagement between the two edge portions 18 and
20 the damper blade is finished by inserting at either end, subsequent to the release
of the external pressure, an end member 26 as shown in Figs 4 and 5 having a form
fitting into the internal cross-sectional profile of the damper blade. In its outermost
portion the end member 26 has a bottom part 26a covering the edge of the wall member
17 and in which a slit, not shown, is provided for the sealing strip 25. As shown
in Fig. 5 the bottom part 26a has a curved external surface the function of which
forms the subject matter of Applicant's copending application No. 1034/81. Inside
the bottom part 26a the end member 26 has a fitting part 26b corresponding to the
internal cross-sectional profile of the damper blade and having lateral surfaces in
engagement with the internal surfaces of the wall member 17 and with the valley of
the S-shaped edge flange 21 located at the extreme part 21a and facing the interior
of the damper blade. As a consequence of said engagement the edge portions 18 and
20 are kept firmly in mutually locking engagement. Said locking engagement further
provides for obtaining a firm squeezing of the sealing strip 25 which by virtue of
its elasticity further keeps the edge flange 19 pressed outwardly towards the opposed
part of the wall member 17, thereby contributing to firmly damp the extreme part 21a
of the edge flange 21 in the opening of the U-shaped cross-section of the edge portion
18.
[0021] However, as shown in Fig. 6 the arrangement of a sealing strip is not mandatory to
secure the engagement between edge portions having the illustrated shape. The damper
blade shown in Fig. 6 is composed of two wall members 30 and 31 which may be formed
in a rolling operation in the same manner as the wall member 17 in Fig. 3 but without
being subjected to any bending or folding as shown at 24 in Fig. 3. Each of the wall
members 30 and 31 comprises a first edge portion 32 and 33, resp., having the same
shape as the edge portion 18 in the embodiment shown in Fig. 3 and a second edge portion
34 and 35, resp., shaped mainly as the edge portion 20 in the embodiment shown in
Fig. 3, the extreme part 35a of the second edge portion 35 for the wall member 31
showing, however, a more pronounced bending than the extreme part 34a of the second
edge portion 34 of the wall member 30.
[0022] The wall members 30 and 31 are connected by initially providing engagement between
the edge portions 32 and 35 by locating and fastening the extreme part 35a of the
edge portion 35 in the opening of the U-shaped cross-section of the edge portion 32.
After the arrangement of a sealing strip 36 having the same shape as the sealing strip
25 in Fig. 3, engagement is effected between the edge portions 32 and 35 as well as
the opposite edge portions 33 and 34 by the same operation as described above, during
which end members, not shown, are simultaneously inserted in the same manner as for
the embodiment shown in Fig. 3. to hold the edge portions in place in mutual engagement.
[0023] Thus, by means of the invention a damper blade is formed by a simple construction
without the use of any particular connecting means, which is composed solely of one
or two wall members, two end members matching thereto and, possibly, one or two longitudinal
sealing strips. A particular advantage is the possibility of forming a damper blade
by folding a single wall member or a damper blade having double width by using two
wall members without changing the form of the wall members.
[0024] In addition, the invention may generally be applied to the design of hollow wing-shaped
profiles having walls consisting of quadrilateral plate members, particularly for
plate wings for use in axial flow fans whereby the plate members may have an oblong
trapezoidal form or for guide vanes and blades for centrifugal fans.
1. An edgewise profiled, quadrilateral plate member to be used as a wall member in
a hollow wing-shaped profile, in particular a damper blade, a guide nlade or a vane,
characterized by forming the plate member into a wing-shaped cross-sectional profile
by lomgitudinal rolling and/or bending, and by forming along one of its opposite longitudinal
edges of the plate member a first edge portion (18, 32, 33) having an edge flange
(19) bent once into substantially U-shaped cross-section and at the other of said
longitudinal edges a second edge portion (20, 34, 35) having an edge flange (21) bent
by two successive, oppositely directed bendings into a substantially S-shaped cross-section
for engagement with said first edge portion of the same plate member or of another
opposed plate member by pressing the extreme portion (21a, 34a, 35a) of the edge flange
(21) of said second edge portion (20, 34, 35) into the opening behind the edge flange
of the first edge portion (18, 32, 33), said edge flanges being locked in said engagement
by end members fitting into the internal cross-section of said hollow profile.
2. A damper blade for a ventilation damper assembly of the type in which a number
of substantially rectangular damper blades (7-10) of wing-shaped cross-sectional profile
is pivotally suspended with parallel axes of rotation between opposite frame members
(1,3) in a substantially rectangular damper frame for mounting in an apparatus cabinet,
in a ventilation duct or in a wall opening, so that the damper blades (7-10) can be
moved between a closing position and an opening position by rotation about said axes,
characterized in that a wall member (17, 30, 31) of the damper blade is made from
a rectangular plate member by longitudinal rolling and/or bending into said wing-shaped
cross-sectional profile, said plate member being formed along one of its opposite
longitudinal edges with a first edge portion (18, 32, 33) having an edge flange (19)
bent once into a substantially U-shaped cross-section and at the other of said longitudinal
edges a second edge portion (20, 34, 35) with an edge flange (21) bent by two successive,
oppositely directed bendings into a substantially S-shaped cross-section, said first
and second edge portions (18, 20; 32-35) of the same wall member (17) or of two different,
opposed wall members (30, 31) being put into engagement with each other by pressing
the extreme portion (21a, 34a, 35a) of the edge flange (21) of said second edge portion
(20, 34, 35) into the opening behind the edge flange of said first edge portion (18,
32, 33) and being locked in said engagement by end members (26) fitting into the internal
cross-section of the damper blade to receive the rotational shaft or journals of the
damper blade.
3. A damper blade according to claim 2, characterized in that a.sealing member (25,
36) is arranged as a lobe seal between opposite sides of the edge flanges of said
first and second edge portion (18, 20; 32, 34) and is clamped by their mutual engagement.