Title of Invention	FAN BLADE
Abstract	The present invention relates to a fan blade for arial fans with a blade body (1), consisting of an inner inlaid part (3) and of an outer blade shaped part (2) partially enclosing said inner inlaid part (3), which consists of a material of lower rigidity than the inlaid part (3), wherein the inlaid part (3) is constructed as an essentially flat metal part adapted to the shape of the blade body (1), which in the fan blade base region (7) has an uncoated smooth fixing section (4).

Title of Invention

FAN BLADE

Abstract

The present invention relates to a fan blade for arial fans with a blade body (1), consisting of an inner inlaid part (3) and of an outer blade shaped part (2) partially enclosing said inner inlaid part (3), which consists of a material of lower rigidity than the inlaid part (3), wherein the inlaid part (3) is constructed as an essentially flat metal part adapted to the shape of the blade body (1), which in the fan blade base region (7) has an uncoated smooth fixing section (4).

Full Text	FAN BLADE The present invention relates to a fan blade for an axial fan with a blade body consisting of an inner inlaid part and an outer blade shaped part which partially encases said inner inlaid part and is made of a less strong materia, than the inlaid part. A fan blade of this type is known from EP 1 571 34 6 A2. In this case, the inlaid part consists of two plate- shaped individual parts which are arranged perpendicularly to each other. As a result of this embodiment of the inlaid part, the blade body must be relatively thick in order completely to enclose the inlaid part. This both gives rise to higher material costs and increases the centrifugal force of the rotating blade wheel, leading to increased loading of forces. In addition, the manufacture and preassembly of the two plate-shaped individual parts are costly. The present invention is based on the object of providing a fan blade which on the one hand allows inexpensive manufacture and assembly and is subject, almost in the shank longitudinal direction on rotation, to substantially no material lengthening. According to the invention, this is achieved in that the inlaid part is embodied as a planar metal part which is adapted substantially to the shape of the blade body and has in the fan blade base region an uncoated flat fastening portion. According to the invention, the blade shaped part is embodied as a plastics material injection-molded part. According to the invention, the fastening portion does not protrude relative to the outer fan blade contour; on the contrary, the fastening portion is integrated in the blade contour. The flat, planar embodiment of the fastening portion facilitates easy assembly of the fan blade according to the invention with simultaneous orientation. As a result of the configuration according to the invention, a large proportion of the fan blade wheel according to the invention consists in its interior of the inlaid part itself which can be relatively thin in its embodiment; for example, it can be made of a 2 mm-thick steel sheet or of aluminum sheet. The plastics material sheathing is in this case such that a covering of the inlaid part is attained, although the plastics material volume can be kept low. Preferably, the fastening portion is arranged roughly centrally in the fan blade base region and extends directly from the edge of the base region into the blade shaped part. This allows a very uniform introduction of force into the fan blade wheel and the drive and centrifugal forces are accommodated directly by the inlaid part, as a result of which the plastics material blade shaped part is relieved in terms of force, so that said blade shaped part is not lengthened during operation. The invention further relates to a fan wheel using the fan blade according to the invention. Advantageous embodiments of the fan blade according to the invention are contained in the sub-claims and the invention will be described in greater detail with reference to the exemplary embodiments illustrated in the appended drawings, in which: Fig. 1 is a view onto a fan blade according to the invention; Fig. 2 is a view onto the fan blade according to Fig. 1, but in a longitudinal section above the inlaid part; Fig. 3 is an individual view of the inlaid part according to Fig. 2; Fig. 4 is a side view of an inlaid part according to the invention; Fig. 5 is a view of a fan wheel according to the invention; and Fig. 6 is an individual view of a fan wheel according to Fig. 5. A fan blade according to the invention consists of a blade body 1 which is formed from an inlaid part 3 and an outer blade shaped part 2 partially encasing said inlaid part. The inlaid part 3 is embedded in the blade shaped part 2 and completely enclosed apart from its uncoated fastening portion 4. The blade shaped part 2 is preferably manufactured as a plastics material sprayed part and the inlaid part 3 is simultaneously sheathed during the process of spraying the plastics material sprayed part. The plastics material used is in particular a polyamide plastics material or polypropylene or polybutylene terephthalate (PBT). According to the invention, it can be expedient if the inlaid part 3 is provided with a primer layer as an adhesion promoter prior to the sheathing. As may be seen from Fig. 1, the fastening portion 4 remains uncoated so that the inlaid part 3, which is made of sheet metal, can be fastened here so as to abut directly against a fastening flange of a hub of a fan wheel. For fastening, the fastening portion 4 has a hole 5 through which the required fastening screw 26 can be fed. Also formed in the fastening portion 4 are alignment recesses 6 into which adapted projections 24 on the fastening flemge 22 of the fan hub 21 fit (see Fig. 5 and 6) . The fastening portion 4 is embodied so as to be flat and planar, thus allowing abutment against the corresponding fastening flange over the entire area. As may be seen from Fig. 1 and 2, the fastening portion 4 is arranged roughly centrally in the fan blade base region 7 and extends directly from the edge 8 of the basse region 7 into the blade shaped part 2. The inlaid part 3 thus does not protrude with its fastening portion 4 beyond the edge 8, but rather is integrated within the blade shaped part 2. As may be seen in particular from Fig. 4, the inlaid part 3 is embodied, starting from the fastening portion 4, as an arched shaped part. In this case, arching is present both in the direction of the longitudinal axis Y-Y and in the direction of the transverse axis X-X. The fan blade according to the invention also has corresponding arching. As the fastening portion 4 is embodied in a flat manner, said fastening portion is comprised by a transition region 10 which is arched in the opposite direction. The figure also reveals that the inlaid part 3 has two stiffening ribs 12 in the illustrated exemplary embodiment. These stiffening ribs 12 run in a spoke-like manner from the circumference of the fastening portion 4 in the direction of the longitudinal extension or of the longitudinal axis Y-Y of the blade body 1 or of the inlaid part 3. These stiffening ribs 12 are impressed into the material of the inlaid part 3. Advartageously, the inlaid part 3 is made of a steel sheet or an aluminum sheet having a thickness of for example 2 mm. It may also be seen that the inlaid part 3 has a plurality of apertures 13 which are formed in its surface and can be embodied in particular in a circular or else elliptical manner. The plastics material can pass through these apertures 13 during the sheathing of the blade shaped part 2 with the plastics material, so that the plastics material is through-connected on both sides of the inlaid part 3. The distribution of the apertures 13 is such that the plurality of apertures 13 are arranged between the end of the stiffening ribs 12 and the base portion 7 of the end opposing the blade shaped part 2 and also in the direction of rotation of the fan blade wheel or of the fan blade in the region between the stiffening ribs 12 and the respective rear longitudinal edge 11 of the fan blade. Thus, the apertures 13 are arranged in such a way and at locations such that they are present in the regions and ensure through-connection of the plastics material where the greatest plastics material overlap is present. Apertures 13 are also formed in the immediate vicinity of the transition portion 10. If the stiffening ribs 12 are also completely enclosed by the plastics material of the blade shaped part 2, a form- fitting and force-transmitting connection . is established here too between, the two bodies. Fig. 2 shows that the shape of the inlaid part 3 and the shape of the blade body 1 are adapted in such a way that the delimiting edges of the blade body 1 and of the inlaid part 3 coincide in the base region 7 and the two opposing delimiting edges in the longitudinal direction Y-Y of the inla.id part 3 and also the corresponding delimiting edges of the blade body 1 run relative to one another in such a way that an extending gap region is present between these edges, starting from the base region 7. In this case, the gap region 14 is embodied so as to be very much larger in the region of the, in the direction of rotation, rear delimiting edges 11, 11a than the gap region 15 of the, in the direction of rotation, front longitudinal edges 11b, 11c, i.e. only a small overlap of the blade shaped part 2 relative to the inlaid part 3 is present in the, in the direction of rotation, front region of the blade body. Expediently, the inlaid part 3 has a maximum length 1 which is about 60 % to 85 %, preferably approx. 75% to 80% of the maximum length L of the blade body 1. Furthermore, the inlaid part 3 has a maximum width b which is 35 % to 60 %, preferably 38 % to 53 % of the maximum width B of the blade body 1. The invention thus provides an adaptation of the inlaid part 3 and blade shaped part 2 leading to optimum distribution of force within the fan blade, so that changes in length of the fan blade shaped part 2 are avoided. A fan wheel 20 according to the invention consists of a hollow cylindrical hub 21 on the circumference of which fastening flanges 22 are embodied. The fan blades according to the invention are fastened to these fastening flanges 22. The hub 21 is made of diecast aluminum or of steel and can form the rotor of a DC motor. The fastening portion 4 of the fan blades according to the invention is fastened to the fastening flanges 22. In the case of a diecast aluminum rotor, the fastening flanges 22 can be cast onto the rotor. If, on the other hand,, the rotor is, as illustrated in Fig. 5 and 6, made of steel, then the fastening flanges 22 are welded onto the hub 21 over the circumference. The fastening flanges 22 can expediently be manufactured as punched parts or punched bent parts. Owing to the fastening according to the invention by welding-on of the fastening flanges 22, the size and orientation of the blade shaped parts 2 can be varied in any desired manner, The fastening flanges 22 can be embodied as a sheet steel punched bent part consisting of a central abutment portion 27 having in each case stiffening webs 29 which are bent over at its longitudinal sides 28. The stiffening webs 29 have a substantially triangular shape, the stiffening webs 29 tapering toward the free end of the abutment portions 27. This produces an embodiment of the fastening flanges 22 that is U-shaped in cross section, in particular in the lower fastening region, where they are welded onto the hub 21. The invention is not restricted to the illustrated and described exemplary embodiments, but rather includes all embodiments which are equivalent in the sense of the invention. Furthermore, the invention is also far from being restricted to the combination of features defined in claim 1, but rather can also be defined by any other desired combination of specific features of all individual features disclosed as a whole. This means that in principle almost any individual feature of claim 1 may be omitted or replaced by at least one individual feature disclosed at a different point of the application. To this extent, claim 1 should be understood merely as a first attempt to formulate an invention. Patent claims 1. A fan blade for axial fans with a blade body (1), consisting of an inner inlaid part (3) and an outer blade shaped part (2) which partially encases said inner inlaid part and is made of a less strong material than the inlaid part (3), characterized in that the inlaid part (3) is embodied as a planar metal part which is adapted substantially to the shape of the blade body (1) and has in the fan blade base region (7) an uncoated flat fastening portion (4). 2. The fan blade as claimed in claim 1, characterized in that the blade shaped part (2) is embodied as a plastics material injection-molded part. 3. The fan blace as claimed in claim 1 or 2, characterized in that the fastening portion (4) is arranged roughly centrally in the fan blade base region (7) and extends directly from the edge of the base region (7) into the blade shaped part (2). 4. The fan blade as claimed in one of claims 1 to 3, characterized in that the inlaid part (3) has, starting from the fastening portion (4), an arched contour in both the blade body longitudinal direction and the blade body transverse direction and in that the fastening portion (1) is enclosed by a transition region (10) which is arched in the opposite direction thereto, starting from the edge of the base region (7). 5. The fan blade as claimed in one of claims 1 to 4, characterized in that the inlaid part (3) has at least one stiffening rib (12) which runs in a spoke- like manner from the circumference of the fastening portion (4) in the direction of the longitudinal axis (Y-Y) of the blade body (1). 6. The fan blade as claimed in one of claims 1 to 5, characterized in that the inlaid part (3) has a plurality of apertures (13) formed in its surface. 7. The fan blade as claimed in claim 6, characterized in that the plurality of apertures (13) are formed between the end of the stiffening rib (12) and the end of the blade body (1) that opposes the base portion (7) and also in the region lying in the direction of rotation of the fan blade and between the stiffening rib (12) and the longitudinal edge, lying in the direction of rotation, of the blade body (1). 8. The fan blade as claimed in one of claims 1 to 7, characterized in that the shape of the inlaid part (3) and the shape of the blade body (1) are adapted to each other in such a way that the delimiting edges of the blade body and of the inlaid part (3) coincide in the base region (7) and the two opposing delimiting edges (11a, 11c) in the longitudinal direction of the inlaid part (3) and the corresponding delimiting edges (11, 11b) of the blade body (1) are adapted to one another in such a way that an extending gap region (14, 15) is formed betweer: these edges, starting from the base region (7). 9. The fan blade as claimed in one of claims 1 to 8, characterized in that the inlaid part (3) has a maximum length (1) which is 60 % to 85 %, preferably 75 % to 80 % of the maximum length (L) of the blade body (1). 10. The fan blade as claimed in one of claims 1 to 9, characterized in that the inlaid part (3) has a maximum width (b) which is 35 % to 60 %, preferably 38 % to 53 % of the maximum width (B) of the blade body (1). 11. A fan wheel, consisting of a hub (21) and of fan blades which are formed from said hub and fastened to fastening flanges (22), characterized in that the fan blades are embodied as claimed in one of claims 1 to 10 and the fastening flanges (22) are made of steel and are connected to the hub (21) by welding. 12. The fan wheel as claimed in claim 11, characterized in that the sheet steel fastening flanges (22) are embodied as shaped or shaped bent parts and consist of a flat abutment portion (27) and stiffening webs (29) which are bent down at the two opposing longitudinal sides (28) of said abutment portion, wherein the abutment portion of the fastening flanges (22) enters into abutment with the fastening portion (4) of the inlaid part (3). 13. A fan wheel, consisting of a hub (21) and of fan blades which are formed from said hub and fastened to fastening flanges (22), characterized in that the fan blades are embodied as claimed in one of claims 1 to 10 and both the hub (21) and the fastening flanges (22) are made of diecast aluminum and are joined together in one piece. The present invention relates to a fan blade for arial fans with a blade body (1), consisting of an inner inlaid part (3) and of an outer blade shaped part (2) partially enclosing said inner inlaid part (3), which consists of a material of lower rigidity than the inlaid part (3), wherein the inlaid part (3) is constructed as an essentially flat metal part adapted to the shape of the blade body (1), which in the fan blade base region (7) has an uncoated smooth fixing section (4).

Full Text

FAN BLADE
The present invention relates to a fan blade for an
axial fan with a blade body consisting of an inner
inlaid part and an outer blade shaped part which
partially encases said inner inlaid part and is made of
a less strong materia, than the inlaid part.
A fan blade of this type is known from EP 1 571 34 6 A2.
In this case, the inlaid part consists of two plate-
shaped individual parts which are arranged
perpendicularly to each other. As a result of this
embodiment of the inlaid part, the blade body must be
relatively thick in order completely to enclose the
inlaid part. This both gives rise to higher material
costs and increases the centrifugal force of the
rotating blade wheel, leading to increased loading of
forces. In addition, the manufacture and preassembly of
the two plate-shaped individual parts are costly.
The present invention is based on the object of
providing a fan blade which on the one hand allows
inexpensive manufacture and assembly and is subject,
almost in the shank longitudinal direction on rotation,
to substantially no material lengthening.
According to the invention, this is achieved in that
the inlaid part is embodied as a planar metal part
which is adapted substantially to the shape of the
blade body and has in the fan blade base region an
uncoated flat fastening portion. According to the
invention, the blade shaped part is embodied as a
plastics material injection-molded part. According to
the invention, the fastening portion does not protrude
relative to the outer fan blade contour; on the
contrary, the fastening portion is integrated in the
blade contour. The flat, planar embodiment of the
fastening portion facilitates easy assembly of the fan

blade according to the invention with simultaneous
orientation. As a result of the configuration according
to the invention, a large proportion of the fan blade
wheel according to the invention consists in its
interior of the inlaid part itself which can be
relatively thin in its embodiment; for example, it can
be made of a 2 mm-thick steel sheet or of aluminum
sheet. The plastics material sheathing is in this case
such that a covering of the inlaid part is attained,
although the plastics material volume can be kept low.
Preferably, the fastening portion is arranged roughly
centrally in the fan blade base region and extends
directly from the edge of the base region into the
blade shaped part. This allows a very uniform
introduction of force into the fan blade wheel and the
drive and centrifugal forces are accommodated directly
by the inlaid part, as a result of which the plastics
material blade shaped part is relieved in terms of
force, so that said blade shaped part is not lengthened
during operation.
The invention further relates to a fan wheel using the
fan blade according to the invention.
Advantageous embodiments of the fan blade according to
the invention are contained in the sub-claims and the
invention will be described in greater detail with
reference to the exemplary embodiments illustrated in
the appended drawings, in which:
Fig. 1 is a view onto a fan blade according to the
invention;
Fig. 2 is a view onto the fan blade according to Fig.
1, but in a longitudinal section above the inlaid part;
Fig. 3 is an individual view of the inlaid part
according to Fig. 2;

Fig. 4 is a side view of an inlaid part according to
the invention;
Fig. 5 is a view of a fan wheel according to the
invention; and
Fig. 6 is an individual view of a fan wheel according
to Fig. 5.
A fan blade according to the invention consists of a
blade body 1 which is formed from an inlaid part 3 and
an outer blade shaped part 2 partially encasing said
inlaid part. The inlaid part 3 is embedded in the blade
shaped part 2 and completely enclosed apart from its
uncoated fastening portion 4. The blade shaped part 2
is preferably manufactured as a plastics material
sprayed part and the inlaid part 3 is simultaneously
sheathed during the process of spraying the plastics
material sprayed part. The plastics material used is in
particular a polyamide plastics material or
polypropylene or polybutylene terephthalate (PBT).
According to the invention, it can be expedient if the
inlaid part 3 is provided with a primer layer as an
adhesion promoter prior to the sheathing. As may be
seen from Fig. 1, the fastening portion 4 remains
uncoated so that the inlaid part 3, which is made of
sheet metal, can be fastened here so as to abut
directly against a fastening flange of a hub of a fan
wheel. For fastening, the fastening portion 4 has a
hole 5 through which the required fastening screw 26
can be fed. Also formed in the fastening portion 4 are
alignment recesses 6 into which adapted projections 24
on the fastening flemge 22 of the fan hub 21 fit (see
Fig. 5 and 6) . The fastening portion 4 is embodied so
as to be flat and planar, thus allowing abutment
against the corresponding fastening flange over the
entire area. As may be seen from Fig. 1 and 2, the

fastening portion 4 is arranged roughly centrally in
the fan blade base region 7 and extends directly from
the edge 8 of the basse region 7 into the blade shaped
part 2. The inlaid part 3 thus does not protrude with
its fastening portion 4 beyond the edge 8, but rather
is integrated within the blade shaped part 2. As may be
seen in particular from Fig. 4, the inlaid part 3 is
embodied, starting from the fastening portion 4, as an
arched shaped part. In this case, arching is present
both in the direction of the longitudinal axis Y-Y and
in the direction of the transverse axis X-X. The fan
blade according to the invention also has corresponding
arching. As the fastening portion 4 is embodied in a
flat manner, said fastening portion is comprised by a
transition region 10 which is arched in the opposite
direction. The figure also reveals that the inlaid part
3 has two stiffening ribs 12 in the illustrated
exemplary embodiment. These stiffening ribs 12 run in a
spoke-like manner from the circumference of the
fastening portion 4 in the direction of the
longitudinal extension or of the longitudinal axis Y-Y
of the blade body 1 or of the inlaid part 3. These
stiffening ribs 12 are impressed into the material of
the inlaid part 3. Advartageously, the inlaid part 3 is
made of a steel sheet or an aluminum sheet having a
thickness of for example 2 mm. It may also be seen that
the inlaid part 3 has a plurality of apertures 13 which
are formed in its surface and can be embodied in
particular in a circular or else elliptical manner. The
plastics material can pass through these apertures 13
during the sheathing of the blade shaped part 2 with
the plastics material, so that the plastics material is
through-connected on both sides of the inlaid part 3.
The distribution of the apertures 13 is such that the
plurality of apertures 13 are arranged between the end
of the stiffening ribs 12 and the base portion 7 of the
end opposing the blade shaped part 2 and also in the

direction of rotation of the fan blade wheel or of the
fan blade in the region between the stiffening ribs 12
and the respective rear longitudinal edge 11 of the fan
blade. Thus, the apertures 13 are arranged in such a
way and at locations such that they are present in the
regions and ensure through-connection of the plastics
material where the greatest plastics material overlap
is present. Apertures 13 are also formed in the
immediate vicinity of the transition portion 10. If the
stiffening ribs 12 are also completely enclosed by the
plastics material of the blade shaped part 2, a form-
fitting and force-transmitting connection . is
established here too between, the two bodies.
Fig. 2 shows that the shape of the inlaid part 3 and
the shape of the blade body 1 are adapted in such a way
that the delimiting edges of the blade body 1 and of
the inlaid part 3 coincide in the base region 7 and the
two opposing delimiting edges in the longitudinal
direction Y-Y of the inla.id part 3 and also the
corresponding delimiting edges of the blade body 1 run
relative to one another in such a way that an extending
gap region is present between these edges, starting
from the base region 7. In this case, the gap region 14
is embodied so as to be very much larger in the region
of the, in the direction of rotation, rear delimiting
edges 11, 11a than the gap region 15 of the, in the
direction of rotation, front longitudinal edges 11b,
11c, i.e. only a small overlap of the blade shaped part
2 relative to the inlaid part 3 is present in the, in
the direction of rotation, front region of the blade
body. Expediently, the inlaid part 3 has a maximum
length 1 which is about 60 % to 85 %, preferably
approx. 75% to 80% of the maximum length L of the
blade body 1. Furthermore, the inlaid part 3 has a
maximum width b which is 35 % to 60 %, preferably 38 %
to 53 % of the maximum width B of the blade body 1.

The invention thus provides an adaptation of the inlaid
part 3 and blade shaped part 2 leading to optimum
distribution of force within the fan blade, so that
changes in length of the fan blade shaped part 2 are
avoided.
A fan wheel 20 according to the invention consists of a
hollow cylindrical hub 21 on the circumference of which
fastening flanges 22 are embodied. The fan blades
according to the invention are fastened to these
fastening flanges 22. The hub 21 is made of diecast
aluminum or of steel and can form the rotor of a DC
motor. The fastening portion 4 of the fan blades
according to the invention is fastened to the fastening
flanges 22. In the case of a diecast aluminum rotor,
the fastening flanges 22 can be cast onto the rotor.
If, on the other hand,, the rotor is, as illustrated in
Fig. 5 and 6, made of steel, then the fastening flanges
22 are welded onto the hub 21 over the circumference.
The fastening flanges 22 can expediently be
manufactured as punched parts or punched bent parts.
Owing to the fastening according to the invention by
welding-on of the fastening flanges 22, the size and
orientation of the blade shaped parts 2 can be varied
in any desired manner, The fastening flanges 22 can be
embodied as a sheet steel punched bent part consisting
of a central abutment portion 27 having in each case
stiffening webs 29 which are bent over at its
longitudinal sides 28. The stiffening webs 29 have a
substantially triangular shape, the stiffening webs 29
tapering toward the free end of the abutment portions
27. This produces an embodiment of the fastening
flanges 22 that is U-shaped in cross section, in
particular in the lower fastening region, where they
are welded onto the hub 21.
The invention is not restricted to the illustrated and
described exemplary embodiments, but rather includes

all embodiments which are equivalent in the sense of
the invention. Furthermore, the invention is also far
from being restricted to the combination of features
defined in claim 1, but rather can also be defined by
any other desired combination of specific features of
all individual features disclosed as a whole. This
means that in principle almost any individual feature
of claim 1 may be omitted or replaced by at least one
individual feature disclosed at a different point of
the application. To this extent, claim 1 should be
understood merely as a first attempt to formulate an
invention.

Patent claims
1. A fan blade for axial fans with a blade body
(1), consisting of an inner inlaid part (3) and an
outer blade shaped part (2) which partially encases
said inner inlaid part and is made of a less strong
material than the inlaid part (3), characterized in
that the inlaid part (3) is embodied as a planar metal
part which is adapted substantially to the shape of the
blade body (1) and has in the fan blade base region (7)
an uncoated flat fastening portion (4).
2. The fan blade as claimed in claim 1,
characterized in that the blade shaped part (2) is
embodied as a plastics material injection-molded part.
3. The fan blace as claimed in claim 1 or 2,
characterized in that the fastening portion (4) is
arranged roughly centrally in the fan blade base region
(7) and extends directly from the edge of the base
region (7) into the blade shaped part (2).
4. The fan blade as claimed in one of claims 1 to
3, characterized in that the inlaid part (3) has,
starting from the fastening portion (4), an arched
contour in both the blade body longitudinal direction
and the blade body transverse direction and in that the
fastening portion (1) is enclosed by a transition
region (10) which is arched in the opposite direction
thereto, starting from the edge of the base region (7).
5. The fan blade as claimed in one of claims 1 to
4, characterized in that the inlaid part (3) has at
least one stiffening rib (12) which runs in a spoke-
like manner from the circumference of the fastening
portion (4) in the direction of the longitudinal axis
(Y-Y) of the blade body (1).

6. The fan blade as claimed in one of claims 1 to
5, characterized in that the inlaid part (3) has a
plurality of apertures (13) formed in its surface.
7. The fan blade as claimed in claim 6,
characterized in that the plurality of apertures (13)
are formed between the end of the stiffening rib (12)
and the end of the blade body (1) that opposes the base
portion (7) and also in the region lying in the
direction of rotation of the fan blade and between the
stiffening rib (12) and the longitudinal edge, lying in
the direction of rotation, of the blade body (1).
8. The fan blade as claimed in one of claims 1 to
7, characterized in that the shape of the inlaid part
(3) and the shape of the blade body (1) are adapted to
each other in such a way that the delimiting edges of
the blade body and of the inlaid part (3) coincide in
the base region (7) and the two opposing delimiting
edges (11a, 11c) in the longitudinal direction of the
inlaid part (3) and the corresponding delimiting edges
(11, 11b) of the blade body (1) are adapted to one
another in such a way that an extending gap region (14,
15) is formed betweer: these edges, starting from the
base region (7).
9. The fan blade as claimed in one of claims 1 to
8, characterized in that the inlaid part (3) has a
maximum length (1) which is 60 % to 85 %, preferably 75
% to 80 % of the maximum length (L) of the blade body
(1).
10. The fan blade as claimed in one of claims 1 to
9, characterized in that the inlaid part (3) has a
maximum width (b) which is 35 % to 60 %, preferably 38
% to 53 % of the maximum width (B) of the blade body
(1).

11. A fan wheel, consisting of a hub (21) and of
fan blades which are formed from said hub and fastened
to fastening flanges (22), characterized in that the
fan blades are embodied as claimed in one of claims 1
to 10 and the fastening flanges (22) are made of steel
and are connected to the hub (21) by welding.
12. The fan wheel as claimed in claim 11,
characterized in that the sheet steel fastening flanges
(22) are embodied as shaped or shaped bent parts and
consist of a flat abutment portion (27) and stiffening
webs (29) which are bent down at the two opposing
longitudinal sides (28) of said abutment portion,
wherein the abutment portion of the fastening flanges
(22) enters into abutment with the fastening portion
(4) of the inlaid part (3).
13. A fan wheel, consisting of a hub (21) and of
fan blades which are formed from said hub and fastened
to fastening flanges (22), characterized in that the
fan blades are embodied as claimed in one of claims 1
to 10 and both the hub (21) and the fastening flanges
(22) are made of diecast aluminum and are joined
together in one piece.

The present invention relates to a fan blade for arial
fans with a blade body (1), consisting of an inner
inlaid part (3) and of an outer blade shaped part (2)
partially enclosing said inner inlaid part (3), which
consists of a material of lower rigidity than the
inlaid part (3), wherein the inlaid part (3) is
constructed as an essentially flat metal part adapted
to the shape of the blade body (1), which in the fan
blade base region (7) has an uncoated smooth fixing
section (4).

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Patent Number

279841

Indian Patent Application Number

354/KOLNP/2009

PG Journal Number

05/2017

Publication Date

03-Feb-2017

Grant Date

31-Jan-2017

Date of Filing

27-Jan-2009

Name of Patentee

EBM-PAPST MULFINGEN GMBH & CO. KG

Applicant Address

BACHMÜHLE 2 74673 MULFINGEN

Inventors:

#	Inventor's Name	Inventor's Address
1	STRENG, GUNTER	SPIELBACH 71, 74575 SCHROZBERG
2	BICKEL, ROLF	LINDENWEG 14, 67999 LGERSHEIM
3	MÜLLER, RAINER	SCHIESSHOFER STR. 14, 74639 ZWEIFLINGEN-PFAHLBACH

PCT International Classification Number

F04D 29/34

PCT International Application Number

PCT/EP2007/057963

PCT International Filing date

2007-08-01

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	20 2006 011898.5	2006-08-03	Germany