Flow deflecting assembly

In the outlet part of a fluid passage generally rectangular in cross section defined by two parallel opposed broad walls spaced apart a short distance therebetween and two opposed narrower walls spaced apart a longer distance therebetween, the narrower walls curve outwards forming guide walls, and a row of deflecting blades of curved profile extend between the broad walls and are held in angle-adjustable manner between said curved faces of the guide walls to effectively deflect fluid flow without loss of flow rate by the attachment effect to the curved faces.

BACKGROUND OF THE INVENTION 
1. Field of the Invention: 
The present invention relates generally to a flow deflecting assembly, and 
particularly concerns a flow deflecting assembly suitable for installation 
at the air outlet of an air conditioner so as to deflect the direction of 
flow of conditioned air. 
2. Description of the Prior Art 
In an air conditioner, in order to obtain comfortable air conditioning, air 
from an outlet of the air conditioner should be widely deflectable in 
desired directions. Hitherto a known flow deflecting assembly as disclosed 
in U.S. Pat. No. 3,358,577, which deflects air flow in a direction of 
smaller aspect ratio. As shown in FIG. 1, the deflection of air flow in 
such an assembly is accomplished by making the air flow through curved 
gaps defined by curved blades 1a or 1b. Though it is intended that the 
rate of air flow is not decreased, the apparatus of this prior art could 
not help but decrease the air flow rate because the flow deflection is 
made by greatly tilting the blades about their upstream edges, thereby 
resultantly making the outlet gap A' between adjacent blades smaller than 
the inlet gap A. 
SUMMARY OF THE INVENTION 
Accordingly the present invention intends to provide an improved flow 
deflecting assembly which can deflect the flow of air through a large 
angle without considerable loss of the air flow rate. In order to provide 
the improved flow deflection, the present invention adopts outwardly 
curved guide walls at the outlet end of a fluid passage, and a pair of 
blades each having a curved profile disposed in the vicinity of the curved 
faces of the guide walls to deflect the air therealong. 
That is, the flow deflecting assembly in accordance with the present 
invention comprises 
a fluid passage generally rectangular in cross section, defined by a pair 
of opposed broad walls disposed a short distance apart and a pair of 
opposed narrower walls disposed a longer distance apart and having an 
inlet and an outlet, the narrower walls forming a pair of guide walls 
which have curved faces curving outwards in the vicinity of the outlet, 
a pair of flow deflecting blades of curved profile, which are rotatable 
around center shafts of the blades, extend between the broad walls and are 
respectively disposed in the vicinities of the curved faces of the guide 
walls, gaps D between the shafts and the curved faces of the guide walls 
are smaller than the curvature radius R of the curved faces of the guide 
walls, the rearward edges of the blades are disposed downstream of the 
inlet of the fluid passage but upstream of the curved faces while the 
forward edges of the blades are disposed upstream of the outlet of the 
passage but downstream of the beginning of the curved faces to make the 
fluid flow attach to the curved faces of the guide walls, and 
a row of deflecting blades of curved profile held in angle-adjustable 
manner, which are disposed between the pair of deflecting blades with 
predetermined pitches therebetween. 
As a result of the above-mentioned configuration, by tilting the blades 
with respect to the curved faces of the guide walls, the flow of the fluid 
passing through the gap between the guide walls and the blades and also 
between the blades is deflected to a great extent, and the flow of the 
fluid is attached to the curved faces of the guide walls, thereby 
resultantly greatly deflecting the whole flow in a direction toward the 
end parts of the curved face of the guide wall. In this way, by the 
attachment of the flow of fluid to the curved faces when deflecting the 
flow, in general the tilt angle of the blades may be moderate in 
comparison with that of the conventional flow deflecting assembly, and 
accordingly there is no undesirable lowering of the flow rate. 
The flow deflecting assembly in accordance with the present invention can 
produce a widely diffusing flow by arranging the blades in symmetry with 
the center of the fluid passage.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Hereafter a first embodiment of the present invention is described with 
reference to the drawings FIG. 2 through FIG. 8. The flow deflecting 
assembly comprises a fluid passage 2, for instance an exit air passage of 
an air conditioner, which has an inlet 3 and an outlet 4. The fluid 
passage 2 is generally rectangular in cross section and is defined by a 
pair of space opposed parallel broad walls 21 and 22 which have a small 
gap W therebetween and a pair of space opposed narrower walls which have a 
larger gap S therebetween and have outwardly curved surfaces in the 
vicinity of the outlet 4, thereby forming guide walls 5 and 6. 
A pair of flow deflecting blades 7 and 8 of curved profile which extend 
between the walls 21 and 22 and are mounted on rotatable center shafts 7b 
and 8b, are respectively disposed in the vicinities of the curved surfaces 
of the guide walls 5 and 6. Gaps D between the shafts 7b, 8b and the 
respective curved surfaces of the guide walls 5 and 6 are smaller than the 
curvature radius R of the curved surfaces of the guide walls. The forward 
edges 7a and 8a of the blades 7 and 8 are disposed in the fluid flow 
between the guide walls 5 and 6 while the rearward edges are disposed 
upstream of the curved surfaces of the guide walls. Several blades 7L and 
8R mounted on center shafts are provided between the blades 7 and 8 with 
predetermined gaps therewith and inbetween in a row, so as to induce 
attachments of the flow of fluid flowing in the gaps between the guide 
walls 5, 6 and the blades 7, 8 by means of the Coanda effect. Gaps H, as 
shown in FIG. 4, between the shafts of the blades 7 and 7L and between the 
shafts of blades 7L, and similarly between the shafts of blades 8 and 8R 
and between the shafts of blades of 8R are preferably selected to be 
smaller than the chord length l the blades 7L and 8R for the sake of good 
deflection of the flows of the fluid. On the other hand, in order to 
decrease resistance to the flow, the total number of blades across the 
passage 2 is preferably small. Accordingly, the gap H is preferably about 
equal to the length l of the chord. Thus the flow of the fluid such as 
chilled air may be bent by cooperative operation of the guide walls 5 or 6 
and the blades 7, 7R or 8, 8R in the directions shown by the thick white 
arrows in FIG. 6, FIG. 7 and FIG. 8. But the flow is not deflected in a 
direction toward either of the broad walls 21 or 22, because their opposed 
surfaces are flat and disposed parallel to each other. 
When the blades 7, 7L, 8R and 8 are adjusted as shown in FIG. 5, that is, 
when the chords of the blades are arranged in parallel with the center 
axis X--X of the passage 2, as shown in FIG. 5, the flow of the fluid is 
not bent, but is led straight to the outlet 4 as shown by the thick white 
arrows F.sub.L and F.sub.R in FIG. 5. 
Next, as shown in FIG. 6 when the blades 7 and 7L are tilted in a direction 
so that their forward edges approach the curved surface of the guide wall 
5, and the blades 8 and 8R are tilted in a direction so that their forward 
or downstream edges approach the curved surface of the guide wall 6, the 
left part flow "a" is bent so as to be attached to the curved wall 5 by 
operation of the concave face 7a.sub.1 of the blade 7, and the next 
divided flow b is also bent in the same direction so as to be attached to 
the convex face 7b.sub.1 by operation of concave face 7a.sub.2. In a 
similar way, flows of the fluid passing through the gaps between blades 7L 
are bent leftwards, i.e. toward the curved wall 5 by the blades 7L. As a 
result, the flow in the left half part of the passage 2 is deflected 
leftwards, and in symmetry with the left half part of the flow, the right 
half part of the flow is deflected rightwards, as shown in FIG. 6. 
In this case, the downstream edge 7a of the blade 7 (which is shown in FIG. 
2) is disposed upstream of the ending point and downstream of the starting 
point of the curved surfaces of the guide walls 5 and 6, and the gap D 
between the shaft 7b and the curved surface of the guide wall 5 is smaller 
than the curvature radius R of that wall, so that the fluid flow passing 
through the gap between the blade 7 and the curved surface 5 adheres 
effectively to the curved surface 5 (the smaller the ratio of D/R, the 
more effective the adhesion). Further, as the rotation of the blade 7 on 
its center shaft 7b, the ratio of the front gap D.sub.2 to the rear gap 
D.sub.1 (which are shown in FIG. 2) is more easily changeable by means of 
a small angle adjustment of the blade 7, as compared with large angle 
adjustment required by the conventional blades which are shown in FIG. 1, 
so that the fluid flow is accelerated and the adhesion is promoted by the 
squeezing action by the blade, thereby more effectively adhering the flow 
to the curved surface in spite of the small angle adjustment. Further, the 
fluid flows passing through the gaps between the blades 7L are also bent 
toward the curved surface by the blades 7L and invited to adhere to the 
curved surface of the guide wall 5. As a result, in spite of the small 
angle adjustment of the blade 7 and blades 7L, they can obtain a large 
bending angle without losing appreciable flow quantity. 
Next as shown in FIG. 7, when the right half blades 8 and 8R are adjusted 
such that their chords are generally parallel to the chords of the blades 
7 and 7L of the left half part, the flow in the fluid of the right half of 
the passage in the fluid passage 2 is bent moderately leftwards as shown 
in FIG. 7. 
As described with reference to FIG. 5 through FIG. 7, by adjusting the 
angular positions of the blades in various modes, the deflection mode of 
the flow can be changed: such (1) as diffusing to both sides of the 
central axis X--X, (2) directly along the central axis, or (3) in a 
direction left or right of that axis. In either of the first or third 
modes, the flow deflection is made by utilizing the attachment effect of 
the flow, and accordingly there is no need of for excessive tilting of the 
blades. Hence, the rate of flow is not decreased by such deflection. 
Furthermore, by appropriately selecting the ratio of number of blades of 
the left part blades 7L to the right part blades 8R, it is possible to the 
ratio of flow rate of left side flow F.sub.L to right side flow F.sub.R, 
and therefore appropriate flow deflection, corresponding to a desired 
purpose is obtainable. 
Furthermore, as shown in FIG. 8, by providing a pair of blade adjusting 
motors 9 and 10 and further by linking the blade 7 to the blades 7L, and 
also the blade 8 to the blades 8R by connecting rods 11 and 12, 
respectively, the left part flow and the right part flow can be 
individually deflected by remote control. 
A second embodiment of the present invention is described with reference to 
FIG. 9 through FIG. 13. The flow deflecting assembly comprises a fluid 
passage 2, for instance an exit passage of an air conditioner which has an 
inlet 3 and an outlet 4. The fluid passage 2, like that shown in FIG. 2, 
is generally rectangular in cross section and is defined by a pair of 
opposed parallel broad walls which have a small gap therebetween and a 
pair of opposed narrower walls which have a a larger gap therebetween and 
outwardly curved surfaces in the vicinity of the outlet 4, thereby forming 
guide walls 5 and 6. In this embodiment, the blades have a profile of an 
air foil configuration as best shown in FIG. 10. That is, the air foil 
configuration of the blade section has a thick semicircular or 
semi-eliptic part 13a and 14a in the up stream end and the middle stream 
and down stream parts of the blades have concave faces 13b and 14b on one 
side and convex faces 13c and 14c on the other side, wherein the concave 
faces 13b and 14b are for attaching the flow to the curved faces of the 
guide walls 5 and 6, respectively. The blades 13 and 14 are disposed in 
the vicinity of the curved surfaces of the guide walls 5 and 6, and are 
held in a manner that their angles are adjustable, respectively. The 
center shafts of the blades 13 and 14 are disposed with a gap between each 
shaft and its corresponding guide wall which is smaller than the curvature 
radius of the curved surfaces of the guide walls 5 and 6, and roughly on a 
line connecting the curvature centers of the curved surfaces. Blades 15 
and 16 of like airfoil configuration are disposed in a row between the 
blades 13 and 14 with predetermined gaps therewith and inbetween, so as to 
induce attachments of the flow of fluid flowing in the gaps between the 
guide walls 5, 6 and the blades 7, 8 by means of the Coanda effect. Gaps H 
between the blades 13 and 15, 16 and 14 are preferably selected to be 
smaller than chord length l of the blades for the sake of good deflection 
of the flow of the fluid. On the other hand, in order to decrease 
resistance to the flow, the number of blades is preferably small. 
Accordingly, the gap H is preferably about equal of the length l of the 
chord. Thus the flow of the fluid such as chilled air is bent by 
cooporative operation of the guide walls 5 or 6 and blades 13, 15, 16 and 
14 in a direction as shown by thick white arrows in FIG. 11, FIG. 12 and 
FIG. 13. But the flow is not deflected in a direction toward either of the 
broad walls of the passage 2 because the broad walls are flat and disposed 
parallel to each other. 
When the blades 13, 15, 16 and 14 are adjusted as shown in FIG. 11, that 
is, when the chords of the blades are arranged in parallel with the center 
axis X--X of the passage 2, the flow of the fluid is not bent, but is led 
straight to the outlet 4 as shown by the thick white arrows F.sub.L and 
F.sub.R in FIG. 11. 
Next, as shown in FIG. 12 when the blades 13 and 15 are tilted in a 
direction so that their downstream edges approach the curved surface of 
the guide wall 5, and the blades 14 and 16 are tilted in a direction so 
that their downstream edges approach the curved surface of the guide wall 
6, the left part flow "a" is bent so as to be attached to the curved wall 
5 by operation of the concave face 13b of the blade 13, and the next 
divided flow "b" is also bent in the same direction to attach to the 
convex face 13c by means of concave face 15b. In the similar way, flow of 
the fluid passing through the gaps between blades 13 are bent leftwards by 
the blades 15. As a result, the flow in the left half part is deflected 
leftwards, and in symmetry with the left half part of the flow the right 
half part of the flow is deflected rightwards, as shown in FIG. 12. 
Next as shown in FIG. 13, when the right-half-part blades 14 and 16 are 
adjusted such that their chords are generally parallel to the chords of 
the blades 13 and 15 of the left half part, the flow of the fluid of the 
right half part in the fluid passage 2 is bent moderately leftwards as 
shown in FIG. 13. 
As described with reference to FIG. 11 through FIG. 13, by adjusting the 
angular positions of the blades in various modes, the deflection mode of 
the flow can be changed such as: (1) diffusing to both sides of the 
central axis X--X, (2) directly along the central axis, or in a direction 
of left or right. In either deflection (1) or (3), the flow deflection is 
made by utilizing the attachment effect of the flow, and accordingly there 
is no need for excessive tilting of the blades, and since the blades have 
rounded upstream edges the rate of flow is not decreased even when the 
blades are deflected, and hence deflection in a wide angle is achievable. 
Furthermore, by appropriately selecting the ratio of the number of left 
part blades 15 to the number of right part blades 16, it is possible to 
change the ratio of flow rate of left side flow F.sub.L and to rate of 
right side flow F.sub.R, and therefore the appropriate flow deflection 
corresponding to a desired purpose is obtainable. 
A third embodiment is described with reference to the drawings FIG. 14 
through FIG. 16. In FIG. 14, a conventional cross-flow fan 17 is provided 
in the inlet part 3 of the fluid passage 2, and in the midway part and 
outlet part 4 of the fluid passage 2 a pair of curved guide walls 5 and 6 
are provided in a manner that both end parts 18 and 19 of the cross-flow 
fan 17 are disposed in outward offset parts 51 and 61 of the passage 2 
upstream of the guide walls 5 and 6. The reason and effect of the 
above-mentioned configuration is first elucidated with reference to FIG. 
15 showing fluid velocity distribution laterally along a conventional 
cross-flow fan 17 disposed in a conventional fluid passage where there are 
no curved guide walls offset bracing inward of end parts of the cross-flow 
fan and downstream thereof, and second with reference to FIG. 16 which 
shows fluid velocity distribution laterally along the cross-flow fan shown 
in FIG. 14 As shown in FIG. 15, when a cross-flow fan is used 
conventionally, its fluid velocity distribution has three parts V.sub.R , 
V and V.sub.R as shown in FIG. 15. That is, at both end parts of the 
cross-flow fan, reverse direction flows V.sub.R to the main flow V are 
induced and thereby the efficiency of the cross-flow fan is lowered. 
Furthermore, when chilled air is blown, the reverse flow V.sub.R makes 
undesirable water drops at the sides of the fluid passage. However, by 
providing the guide walls 5 and 6 having outwardly curving surfaces at the 
passage outlet and offset parts 51 and 61 embracing both end parts of the 
cross-flow fan, no undesirable reverse flows are induced, and only forward 
flow V is produced by the cross-flow fan. 
By providing the curved walls 5 and 6 in the outlet 4 of the fluid passage 
2, there is no fear of forming water drops due to reverse flows of air, 
and orderly forward flow V of the conditioned air is obtainable as shown 
in FIG. 16. 
FIG. 17 and FIG. 18 show an actual heat pump type air conditioner embodying 
the present invention. In this embodiment, a casing 20 houses a cross-flow 
fan 17 and a heat exchanger 21 in the upstream space of the casing 20. And 
further, the air conditioner comprises a pair of curved guide walls 5 and 
6, offsets upstream thereof in which both end parts of the cross-flow fan 
17 are disposed, a pair of blades 7 and 8 disposed in the vicinity of the 
upstream parts of the guide walls 5 and 6, rows of blades 7L and 8R which 
are disposed between the blades 7 and 8 in uniform pitch dispositions, and 
a horizontal blade 22 for vertical deflection of flow of fluid. The blades 
7 and 7L are connected by a connecting rod 23, and the other blades 8 and 
8R are connected by a connecting rod 24. In this configuration, when the 
cross-flow fan 17 rotates, fluid, such as air which is heat-exchanged by 
the heat exchanger 21, is driven downward by the cross-flow fan 17, and 
then is deflected by the blades 7, 7L, 8R and 8 in the aforementioned 
manner as shown with reference to FIG. 5, FIG. 6, FIG. 7, FIG. 8, FIG. 11, 
FIG. 12 and FIG. 13. Thus, the conditioned air is emitted in wide range of 
deflected directions by adjusting the angles of the blades 7, 7L or 8R, 8. 
As a result of the above-mentioned configuration, the flow deflecting 
assembly can deflect the flow of the output air in a range of as wide as 
about two times the angle of the conventional flow deflection means, as a 
result of utilization of the attachment effect of the curved surface guide 
walls, and therefore comfortable air conditioning is obtainable.