FAN

Abstract

The present invention is to provide a fan, comprising a base and a nozzle mounted on the base. The nozzle has a first wall, a second wall arranged generally parallel to the first wall, and a partition wall located between the first wall and the second wall. The partition wall split the airflow outlet of the base to a first nozzle airflow outlet and a second nozzle airflow outlet. The first wall edge of the second wall is folded in an annularly curved or bent manner to form a first Coanda surface adjacent to the first nozzle airflow outlet and capable of producing the Coanda effect, and the partition wall is folded either inward in an opposite direction of an airflow direction or outward in the airflow direction in an annularly curved or bent manner to form a closed wall, the closed wall forming a second Coanda surface adjacent to the second nozzle airflow outlet and capable of producing the Coanda effect.

Description

BACKGROUND OF THE INVENTION

Technical Field

[0001] The present invention relates to a fan and more particularly to one taking advantage of the Coanda effect to increase the overall flow rate of its output airflow.

Description of Related Art

[0002] Fans typically have blades or vanes, which nevertheless hinder passage of light, are difficult to clean, compromise the portability of fans, and take up considerable space when the fans are used in vehicles.

[0003] A bladeless fan is disclosed in U.S. Pat. No. 2,488,467. Lacking a Coanda surface, however, this bladeless fan does not produce the Coanda effect, meaning the fan cannot entrain an airflow from the surroundings to increase the overall flow rate of the output airflow. In addition, known bladeless fans do not have a diffusion surface for guiding an airflow in a predetermined direction and therefore fail to guide an air current effectively.

[0004] As to bladeless fans with a Coanda surface, it is generally required to increase the volume of the nozzle if it is desired to enlarge the Coanda surface without increasing the nozzle openings. This has been a problem to be solved in the fan industry.

BRIEF SUMMARY OF THE INVENTION

[0005] The objective of the present invention is to solve the aforesaid problem that, in order to enlarge the Coanda surface of a conventional bladeless fan without increasing the nozzle openings, the nozzle of the fan must be increased in volume.

[0006] To achieve the objective, the present invention provide a fan, comprising: a base; and a nozzle mounted on the base and having: a nozzle airflow inlet located at the nozzle and configured as an opening for receiving an airflow ejected from the base; a first wall; a second wall arranged generally parallel to the first wall; a first wall end located at an end of the generally parallelly arranged first and second walls; a second wall end located at an opposite end of the generally parallelly arranged first and second walls; first wall edges, which are wall edges of the generally parallelly arranged first and second walls that jointly extend to a side; second wall edges, which are wall edges of the generally parallelly arranged first and second walls that jointly extend to an opposite side; a partition wall located between the first wall and the second wall; a first nozzle airflow outlet located between the first wall edge of the second wall and the partition wall and configured as an opening for ejecting an airflow; and a second nozzle airflow outlet located between the first wall edge of the first wall and the partition wall and configured as an opening for ejecting an airflow; wherein the first wall edge of the second wall is folded in an annularly curved or bent manner to form a first Coanda surface adjacent to the first nozzle airflow outlet and capable of producing the Coanda effect, and the partition wall is folded either inward in an opposite direction of an airflow direction or outward in the airflow direction in an annularly curved or bent manner to form a closed wall, the closed wall forming a second Coanda surface adjacent to the second nozzle airflow outlet and capable of producing the Coanda effect.

[0007] Further, the second wall edges form a closed side for preventing an outgoing airflow or an opening that allows passage of an airflow.

[0008] Further, the second wall is folded inward in the opposite direction of the airflow direction in an annularly curved or bent manner to form a closed wall for preventing an ingoing airflow, or the second wall is folded outward in the airflow direction in an annularly curved or bent manner to form the first Coanda surface adjacent to the first nozzle airflow outlet and capable of producing the Coanda effect.

[0009] Further, the second wall end is joined with the first wall end to form an annular hollow portion, and the annular hollow portion encircles a central hollow portion that allows passage of light and an airflow.

[0010] Further, the second wall end has a second tightly closing wall for preventing passage of an airflow, and the first wall end has a first tightly closing wall for preventing passage of an airflow.

[0011] Further, there is one said nozzle airflow inlet, provided at the first wall or the second wall; or there are a plurality of said nozzle airflow inlets, provided at the first wall or the second wall.

[0012] Further, the second nozzle airflow outlet formed between the first wall edge of the first wall and the partition wall is a tapered slit, and the first nozzle airflow outlet formed between the first wall edge of the second wall and the partition wall is a tapered slit.

[0013] Further, the second nozzle airflow outlet formed between the first wall edge of the first wall and the partition wall is a rectangular slit, and the first nozzle airflow outlet formed between the first wall edge of the second wall and the partition wall is a rectangular slit.

[0014] Further, the first nozzle airflow outlet or the second nozzle airflow outlet is divided into a plurality of spaces by a plurality of partition plates.

[0015] Further, there are a plurality of said partition walls so as to form a plurality of said second Coanda surfaces as well as a plurality of said second nozzle airflow outlets.

[0016] Further, the second wall has a diffusion surface for guiding an airflow in a predetermined direction.

[0017] Further, the second wall edge of the first wall is folded in an annularly curved or bent manner to form a third tightly closing wall, and the third tightly closing wall is adhesively attached to the second wall to prevent an outgoing airflow.

[0018] Further, the second wall edge of the second wall is folded in an annularly curved or bent manner to form a third tightly closing wall, and the third tightly closing wall is adhesively attached to the first wall to prevent an outgoing airflow.

[0019] Further, the nozzle includes a third tightly closing wall, and the third tightly closing wall has two sides adhesively attached to the first wall and the second wall respectively to prevent an outgoing airflow.

[0020] Further, the base has an internal fan for taking in air and ejecting an airflow, a base airflow inlet for taking in air, and a base airflow outlet for ejecting an airflow.

[0021] Further, the internal fan is a forced-draft fan, a planar fan, or a jet turbine-blade fan.

[0022] Further, the internal fan is a plurality of parallel-connected or series-connected planar fans.

[0023] Further, the base comprises a filter screen provided therein.

[0024] The present invention solves the problem that the Coanda surface of a conventional bladeless fan cannot be enlarged without increasing the volume of the nozzle, if the areas of the nozzle openings are to remain unchanged.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows a partial schematic view of the first example of a nozzle in the present invention.

[0026] FIG. 2 shows a partial schematic view of the second example of the nozzle in the present invention.

[0027] FIG. 3 shows a front schematic view of the first embodiment.

[0028] FIG. 4 shows a sectional schematic view of the first embodiment.

[0029] FIG. 5 shows an exploded schematic view of the second embodiment.

[0030] FIG. 6 shows a sectional schematic view of the second embodiment.

[0031] FIG. 7 shows an external perspective view of the third embodiment.

[0032] FIG. 8 shows a sectional schematic view of the third embodiment.

[0033] FIG. 9 shows an external perspective view of the forth embodiment.

[0034] FIG. 10 shows a sectional schematic view of the forth embodiment.

[0035] FIG. 11 shows a schematic view of an example of a forced-draft fan in the present invention.

[0036] FIG. 12 shows a schematic view of an example of a planar fan in the present invention.

[0037] FIG. 13 shows a schematic view of an example of a jet-turbine fan in the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION

[0038] The nozzle referred to in the present invention is described below with reference to two different embodiments.

[0039] Please refer to FIG. 1 for a partial schematic view of the first example of the nozzle in the present invention.

[0040] As shown in FIG. 1, the nozzle 12, to be mounted on a base to increase the range of airflow input, has a nozzle airflow inlet 121, a first wall 122, a second wall 123, a first wall end 124, a second wall end 125, first wall edges 126, second wall edges 127, a first nozzle airflow outlet 128a, a second nozzle airflow outlet 128b, a diffusion surface 129, a third tightly closing wall 133, and a partition wall 130.

[0041] Located at the nozzle 12, the nozzle airflow inlet 121 is an opening for receiving the airflow ejected from the base. There may be a single nozzle airflow inlet 121 provided at the first wall 122 or the second wall 123. There may alternatively be a plurality of nozzle airflow inlets 121 provided at the first wall 122 or the second wall 123. The second wall 123 is arranged generally parallel to the first wall 122. The first wall end 124 is located at one end of the generally parallelly arranged first and second walls 122 and 123. The second wall end 125 is located at the opposite end of the generally parallelly arranged first and second walls 122 and 123. The first wall edges 126 are wall edges of the generally parallelly arranged first and second walls 122 and 123 that jointly extend to one side. The second wall edges 127 are wall edges of the generally parallelly arranged first and second walls 122 and 123 that jointly extend to the opposite side. In this embodiment, the second wall edges 127 form a closed side for preventing an outgoing airflow. In another preferred embodiment, the second wall edge 127 of the first wall 122 is folded in an annularly curved or bent manner to form a third tightly closing wall 133, and the third tightly closing wall 133 is adhesively attached to the second wall 123 to prevent an outgoing airflow. In yet another preferred embodiment, the second wall edge 127 of the second wall 123 is folded in an annularly curved or bent manner to form a third tightly closing wall 133, and this third tightly closing wall 133 is adhesively attached to the first wall 122 to prevent an outgoing airflow. In still another preferred embodiment, the nozzle 12 includes a third tightly closing wall 133 with two opposite sides adhesively attached to the first wall 122 and the second wall 123 respectively to prevent an outgoing airflow. The partition wall 130 lies between the first wall 122 and the second wall 123. The first nozzle airflow outlet 128a is located between the first wall edge 126 of the second wall 123 and the partition wall 130 and is a tapered opening, or tapered slit, configured for ejecting an airflow. In another preferred embodiment, the first nozzle airflow outlet 128a is a rectangular opening, or rectangular slit, instead. The second nozzle airflow outlet 128b is located between the first wall edge 126 of the first wall 122 and the partition wall 130 and is a tapered opening, or tapered slit, configured for ejecting an airflow. In another preferred embodiment, the second nozzle airflow outlet 128b is a rectangular opening, or rectangular slit, instead. The diffusion surface 129 is formed by the second wall 123 and is configured for guiding an airflow in a predetermined direction.

[0042] The first wall edge 126 of the second wall 123 is folded in an annularly curved or bent manner to form a first Coanda surface 134a adjacent to the first nozzle airflow outlet 128a. The first Coanda surface 134a not only can produce the Coanda effect to increase the overall flow rate of the output airflow, but also helps reduce the overall volume of the nozzle. The partition wall 130 is folded inward (i.e., in the opposite direction of the airflow direction) in an annularly curved or bent manner to form a closed wall for preventing an ingoing airflow, wherein the closed wall forms a second Coanda surface 134b adjacent to the second nozzle airflow outlet 128b and capable of producing the Coanda effect to increase the overall flow rate of the output airflow. Thus, without having to change the areas of the nozzle openings or the volume of the nozzle, the Coanda surfaces can be enlarged to enhance the Coanda effect and thereby raise the overall flow rate of the output airflow. In another preferred embodiment, the partition wall 130 is folded outward (i.e., in the same direction as the airflow direction) in an annularly curved or bent manner to form the second Coanda surface 134b.

[0043] Please refer to FIG. 2 for a partial schematic view of the second example of the nozzle in the present invention.

[0044] As shown in FIG. 2, the nozzle 22, to be mounted on a base to increase the range of airflow input, has a nozzle airflow inlet 221, a first wall 222, a second wall 223, a first wall end 224, a second wall end 225, first wall edges 226, second wall edges 227, a first nozzle airflow outlet 228a, a second nozzle airflow outlet 228b, a diffusion surface 229, a third tightly closing wall 233, and a partition wall 230.

[0045] Located at the nozzle 22, the nozzle airflow inlet 221 is an opening for receiving the airflow ejected from the base. The second wall 223 is arranged generally parallel to the first wall 222. The first wall end 224 is located at one end of the generally parallelly arranged first and second walls 222 and 223. The second wall end 225 is located at the opposite end of the generally parallelly arranged first and second walls 222 and 223. The first wall edges 226 are wall edges of the generally parallelly arranged first and second walls 222 and 223 that jointly extend to one side. The second wall edges 227 are wall edges of the generally parallelly arranged first and second walls 222 and 223 that jointly extend to the opposite side. The second wall edges 227 form a closed side for preventing an outgoing airflow. The partition wall 230 lies between the first wall 222 and the second wall 223. The first nozzle airflow outlet 228a is located between the first wall edge 226 of the second wall 223 and the partition wall 230 and is a tapered opening, or tapered slit, configured for ejecting an airflow. The second nozzle airflow outlet 228b is located between the first wall edge 226 of the first wall 222 and the partition wall 230 and is a tapered opening, or tapered slit, configured for ejecting an airflow. The diffusion surface 229 is formed by the second wall 223 and is configured for guiding an airflow in a predetermined direction.

[0046] The first wall edge 226 of the second wall 223 is folded inward (i.e., in the opposite direction of the airflow direction) in an annularly curved or bent manner to form a closed wall for preventing an ingoing airflow, wherein the closed wall forms a first Coanda surface 234a adjacent to the first nozzle airflow outlet 228a. The first Coanda surface 234a not only can produce the Coanda effect to increase the overall flow rate of the output airflow, but also helps reduce the overall volume of the nozzle. In another preferred embodiment, the second wall 223 is folded outward (i.e., in the airflow direction) in an annularly curved or bent manner to form the first Coanda surface (not shown). The partition wall 230 is folded inward (i.e., in the opposite direction of the airflow direction) in an annularly curved or bent manner to form a closed wall for preventing an ingoing airflow, wherein the closed wall forms a second Coanda surface 234b adjacent to the second nozzle airflow outlet 228b and capable of producing the Coanda effect to increase the overall flow rate of the output airflow. Thus, without having to change the areas of the nozzle openings or the volume of the nozzle, the Coanda surfaces can be enlarged to enhance the Coanda effect and thereby raise the overall flow rate of the output airflow. In another preferred embodiment, the partition wall 230 is folded outward (i.e., in the airflow direction) in an annularly curved or bent manner to form a closed wall with the second Coanda surface (not shown).

[0047] Please refer to FIG. 3 and FIG. 4 for a front view and a sectional view of the first embodiment of the present invention respectively.

[0048] As shown in FIG. 3 and FIG. 4, the fan 30 in the first embodiment of the present invention includes a base 31 and a nozzle 32.

[0049] The base 31 has: an internal fan 311 for taking in air and ejecting an airflow, a base airflow inlet 312 for taking in air, and a base airflow outlet 313 for ejecting an airflow.

[0050] The nozzle 32 is mounted on the base 31. Most of the central portion of the nozzle 32 is hollow to allow passage of light and an airflow and to increase the range of airflow input. The nozzle 32 has: a nozzle airflow inlet 321, which is an opening located at the nozzle 32 and configured for receiving the airflow ejected from the base airflow outlet 313; a first wall 322; a second wall 323 arranged generally parallel to the first wall 322, wherein in this embodiment, a second wall end is joined with a first wall end to form an annular hollow portion that encircles the light- and airflow-penetrable central hollow portion of the nozzle; first wall edges 326, which are wall edges of the generally parallelly arranged first and second walls 322 and 323 that jointly extend to one side; second wall edges 327, which are wall edges of the generally parallelly arranged first and second walls 322 and 323 that jointly extend to the opposite side, wherein the second wall edges 327 form a closed side for preventing an outgoing airflow; a partition wall 330 lying between the first wall 322 and the second wall 323; a first nozzle airflow outlet 328a located between the first wall edge 326 of the second wall 323 and the partition wall 330; a second nozzle airflow outlet 328b located between the first wall edge 326 of the first wall 322 and the partition wall 330, wherein in a preferred embodiment, the first nozzle airflow outlet 328a or the second nozzle airflow outlet 328b is divided by a plurality of partition plates 335 into a plurality of spaces, and the partition wall 330 is supported by the partition plates 335; and a diffusion surface 329 for guiding an airflow in a predetermined direction. The first wall edge 326 of the second wall 323 is folded in an annularly curved or bent manner to form a first Coanda surface 334a adjacent to the first nozzle airflow outlet 328a and capable of producing the Coanda effect to increase the overall flow rate of the output airflow. The partition wall 330 between the first wall 322 and the second wall 323 is folded either inward (i.e., in the opposite direction of the airflow direction) or outward (i.e., in the airflow direction) in an annularly curved or bent manner to form a closed wall, wherein the closed wall forms a second Coanda surface 334b adjacent to the second nozzle airflow outlet 328b and capable of producing the Coanda effect. The diffusion surface 329 guides the output airflow in the predetermined direction.

[0051] Please refer to FIG. 5 and FIG. 6 for an exploded schematic view and a sectional view of the second embodiment of the present invention respectively.

[0052] As shown in FIG. 5 and FIG. 6, the fan 40 in the second embodiment of the present invention includes a base 41 and a nozzle 42.

[0053] The base 41 has: an internal fan 411 for taking in air and ejecting an airflow, a base airflow inlet 412 for taking in air, and a base airflow outlet 413 for ejecting an airflow.

[0054] The nozzle 42 is mounted on the base 41. Most of the central portion of the nozzle 42 is hollow to allow passage of light and an airflow and to increase the range of airflow input. The nozzle 42 has: a nozzle airflow inlet 421, which is an opening located at the nozzle 42 and configured for receiving the airflow ejected from the base airflow outlet 413; a first wall 422; a second wall 423 arranged generally parallel to the first wall 422; a first wall end 424 located at one end of the generally parallelly arranged first and second walls 422 and 423; a second wall end 425 located at the opposite end of the generally parallelly arranged first and second walls 422 and 423, wherein in this embodiment, the second wall end 425 has a second tightly closing wall 4251 for preventing passage of an airflow, and the first wall end 424 has a first tightly closing wall 4241 for preventing passage of an airflow; first wall edges 426, which are wall edges of the generally parallelly arranged first and second walls 422 and 423 that jointly extend to one side; second wall edges 427, which are wall edges of the generally parallelly arranged first and second walls 422 and 423 that jointly extend to the opposite side, wherein in this embodiment, the second wall edges 427 form an opening through which an airflow can pass; a partition wall 430 lying between the first wall 422 and the second wall 423; a first nozzle airflow outlet 428a located between the first wall edge 426 of the second wall 423 and the partition wall 430; a second nozzle airflow outlet 428b located between the first wall edge 426 of the first wall 422 and the partition wall 430; and a diffusion surface 429 for guiding an airflow in a predetermined direction. The first wall edge 426 of the second wall 423 is folded in an annularly curved or bent manner to form a first Coanda surface 434a adjacent to the first nozzle airflow outlet 428a and capable of producing the Coanda effect to increase the overall flow rate of the output airflow. The partition wall 430 between the first wall 422 and the second wall 423 is folded either inward (i.e., in the opposite direction of the airflow direction) or outward (i.e., in the airflow direction) in an annularly curved or bent manner to form a closed wall, wherein the closed wall forms a second Coanda surface 434b adjacent to the second nozzle airflow outlet 428b and capable of producing the Coanda effect. The diffusion surface 429 guides the output airflow in the predetermined direction.

[0055] Please refer to FIG. 7 and FIG. 8 for an external perspective view and a sectional view of the third embodiment of the present invention respectively.

[0056] As shown in FIG. 7 and FIG. 8, the fan 50 in the third embodiment of the present invention includes a base 51 and a nozzle 52.

[0057] The base 51 has: a plurality of internal fans 511 for taking in air and ejecting airflows, wherein the internal fans 511 are planar fans connected in parallel to each other; a base airflow inlet 512 for taking in air; a base airflow outlet 513 for ejecting an airflow; and a filter screen 514 provided in the base 51 to filter the air flowing into the base through the base airflow inlet 512.

[0058] Mounted on the base 51 to increase the range of airflow input, the nozzle 52 has: a nozzle airflow inlet 521, which is an opening located at the nozzle 52 and configured for receiving the airflow ejected from the base airflow outlet 513; a first wall 522; a second wall 523 arranged generally parallel to the first wall 522; a first wall end 524 located at one end of the generally parallelly arranged first and second walls 522 and 523; a second wall end 525 located at the opposite end of the generally parallelly arranged first and second walls 522 and 523, wherein in this embodiment, the second wall end 525 has a second tightly closing wall (not shown) for preventing passage of an airflow, and the first wall end 524 has a first tightly closing wall 5241 for preventing passage of an airflow; first wall edges 526, which are wall edges of the generally parallelly arranged first and second walls 522 and 523 that jointly extend to one side; second wall edges 527, which are wall edges of the generally parallelly arranged first and second walls 522 and 523 that jointly extend to the opposite side, wherein the second wall edges 527 form a closed side for preventing an outgoing airflow; a partition wall 530 lying between the first wall 522 and the second wall 523; a first nozzle airflow outlet 528a located between the first wall edge 526 of the second wall 523 and the partition wall 530; a second nozzle airflow outlet 528b located between the first wall edge 526 of the first wall 522 and the partition wall 530; and a diffusion surface 529 for guiding an airflow in a predetermined direction. The first wall edge 526 of the second wall 523 is folded in an annularly curved or bent manner to form a first Coanda surface 534a adjacent to the first nozzle airflow outlet 528a and capable of producing the Coanda effect to increase the overall flow rate of the output airflow. The partition wall 530 between the first wall 522 and the second wall 523 is folded in an annularly curved or bent manner to form a second Coanda surface 534b adjacent to the second nozzle airflow outlet 528b and capable of producing the Coanda effect. The diffusion surface 529 guides the output airflow in the predetermined direction. In a preferred embodiment, the partition wall 530 is folded either inward (i.e., in the opposite direction of the airflow direction) or outward (i.e., in the airflow direction) in an annularly curved or bent manner to form a closed wall, which in turn forms a plurality of second Coanda surfaces 534b as well as a plurality of second nozzle airflow outlets 528b.

[0059] Please refer to FIG. 9 and FIG. 10 for a external perspective view and a sectional view of the fourth embodiment of the present invention respectively.

[0060] As shown in FIG. 9 and FIG. 10, the fan 60 in the fourth embodiment of the present invention includes a base 61 and a plurality of nozzles 62.

[0061] The base 61 has: a plurality of internal fans 611 for taking in air and ejecting airflows, wherein the internal fans 611 are planar fans connected in series to each other; a base airflow inlet 612 for taking in air; and a base airflow outlet 613 for ejecting an airflow.

[0062] The nozzles 62 are mounted on the base 61. Most of the central portion of each nozzle 62 is hollow to allow passage of light and an airflow and to increase the range of airflow input. Each nozzle 62 has: a nozzle airflow inlet 621, which is an opening located at the nozzle 62 and configured for receiving the airflow ejected from the base airflow outlet 613; a first wall 622; a second wall 623 arranged generally parallel to the first wall 622, wherein in this embodiment, a second wall end is joined with a first wall end to form an annular hollow portion that encircles the light- and airflow-penetrable central hollow portion of the nozzle; first wall edges 626, which are wall edges of the generally parallelly arranged first and second walls 622 and 623 that jointly extend to one side; second wall edges 627, which are wall edges of the generally parallelly arranged first and second walls 622 and 623 that jointly extend to the opposite side, wherein the second wall edges 627 form a closed side for preventing an outgoing airflow; a partition wall 630 lying between the first wall 622 and the second wall 623; a first nozzle airflow outlet 628a located between the first wall edge 626 of the second wall 623 and the partition wall 630; a second nozzle airflow outlet 628b located between the first wall edge 626 of the first wall 622 and the partition wall 630; and a diffusion surface 629 for guiding an airflow in a predetermined direction. The first wall edge 626 of the second wall 623 is folded in an annularly curved or bent manner to form a first Coanda surface 634a adjacent to the first nozzle airflow outlet 628a and capable of producing the Coanda effect to increase the overall flow rate of the output airflow. The partition wall 630 between the first wall 622 and the second wall 623 is folded either inward (i.e., in the opposite direction of the airflow direction) or outward (i.e., in the airflow direction) in an annularly curved or bent manner to form a closed wall, wherein the closed wall forms a second Coanda surface 634b adjacent to the second nozzle airflow outlet 628b and capable of producing the Coanda effect. The diffusion surface 629 guides the output airflow in the predetermined direction.

[0063] FIG. 11 is a schematic view of an example of a forced-draft fan in the present invention. Configured to take in air and eject an airflow, the forced-draft fan 70 disclosed in FIG. 11 has a forced-draft fan airflow outlet 71, a forced-draft fan airflow inlet 72, a forced-draft fan blade 73, and a forced-draft fan motor 74.

[0064] FIG. 12 is a schematic view of an example of a planar fan in the present invention. Configured to take in air and eject an airflow, the planar fan 80 disclosed in FIG. 12 has a planar-fan airflow outlet 81, a planar-fan airflow inlet 82, a planar-fan blade 83, and a planar-fan motor 84.

[0065] FIG. 13 is a schematic view of an example of a jet turbine-blade fan in the present invention. Configured to take in air and eject an airflow, the jet turbine-blade fan 90 disclosed in FIG. 13 has a jet turbine-blade fan airflow outlet 91, a jet turbine-blade fan airflow inlet 92, a jet turbine-blade fan blade 93, and a jet turbine-blade fan motor 94.

[0066] According to the above, the present invention solves the problem that, if the areas of the nozzle openings of a bladeless fan with a Coanda surface are to remain unchanged, the Coanda surface cannot be enlarged without increasing the volume of the nozzle.

[0067] The present invention is such valuable in this field so that submit an application. While example embodiments have been disclosed herein, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of example embodiments of the present application, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. A fan, comprising: a base; and a nozzle mounted on the base and having: a nozzle airflow inlet located at the nozzle and configured as an opening for receiving an airflow ejected from the base; a first wall; a second wall arranged generally parallel to the first wall; a first wall end located at an end of the generally parallelly arranged first and second walls; a second wall end located at an opposite end of the generally parallelly arranged first and second walls; first wall edges, which are wall edges of the generally parallelly arranged first and second walls that jointly extend to a side; second wall edges, which are wall edges of the generally parallelly arranged first and second walls that jointly extend to an opposite side; a partition wall located between the first wall and the second wall; a first nozzle airflow outlet located between the first wall edge of the second wall and the partition wall and configured as an opening for ejecting an airflow; and a second nozzle airflow outlet located between the first wall edge of the first wall and the partition wall and configured as an opening for ejecting an airflow; wherein the first wall edge of the second wall is folded in an annularly curved or bent manner to form a first Coanda surface adjacent to the first nozzle airflow outlet and capable of producing the Coanda effect, and the partition wall is folded either inward in an opposite direction of an airflow direction or outward in the airflow direction in an annularly curved or bent manner to form a closed wall, the closed wall forming a second Coanda surface adjacent to the second nozzle airflow outlet and capable of producing the Coanda effect.

2. The fan of claim 1, wherein the second wall edges form a closed side for preventing an outgoing airflow or an opening that allows passage of an airflow.

3. The fan of claim 1, wherein the second wall is folded inward in the opposite direction of the airflow direction in an annularly curved or bent manner to form a closed wall for preventing an ingoing airflow, or the second wall is folded outward in the airflow direction in an annularly curved or bent manner to form the first Coanda surface adjacent to the first nozzle airflow outlet and capable of producing the Coanda effect.

4. The fan of claim 1, wherein the second wall end is joined with the first wall end to form an annular hollow portion, and the annular hollow portion encircles a central hollow portion that allows passage of light and an airflow.

5. The fan of claim 1, wherein the second wall end has a second tightly closing wall for preventing passage of an airflow, and the first wall end has a first tightly closing wall for preventing passage of an airflow.

6. The fan of claim 1, wherein there is one said nozzle airflow inlet, provided at the first wall or the second wall; or there are a plurality of said nozzle airflow inlets, provided at the first wall or the second wall.

7. The fan of claim 1, wherein the second nozzle airflow outlet formed between the first wall edge of the first wall and the partition wall is a tapered slit, and the first nozzle airflow outlet formed between the first wall edge of the second wall and the partition wall is a tapered slit.

8. The fan of claim 1, wherein the second nozzle airflow outlet formed between the first wall edge of the first wall and the partition wall is a rectangular slit, and the first nozzle airflow outlet formed between the first wall edge of the second wall and the partition wall is a rectangular slit.

9. The fan of claim 1, wherein the first nozzle airflow outlet or the second nozzle airflow outlet is divided into a plurality of spaces by a plurality of partition plates.

10. The fan of claim 1, wherein there are a plurality of said partition walls so as to form a plurality of said second Coanda surfaces as well as a plurality of said second nozzle airflow outlets.

11. The fan of claim 1, wherein the second wall has a diffusion surface for guiding an airflow in a predetermined direction.

12. The fan of claim 1, wherein the second wall edge of the first wall is folded in an annularly curved or bent manner to form a third tightly closing wall, and the third tightly closing wall is adhesively attached to the second wall to prevent an outgoing airflow.

13. The fan of claim 1, wherein the second wall edge of the second wall is folded in an annularly curved or bent manner to form a third tightly closing wall, and the third tightly closing wall is adhesively attached to the first wall to prevent an outgoing airflow.

14. The fan of claim 1, wherein the nozzle includes a third tightly closing wall, and the third tightly closing wall has two sides adhesively attached to the first wall and the second wall respectively to prevent an outgoing airflow.

15. The fan of claim 1, wherein the base has an internal fan for taking in air and ejecting an airflow, a base airflow inlet for taking in air, and a base airflow outlet for ejecting an airflow.

16. The fan of claim 15, wherein the internal fan is a forced-draft fan, a planar fan, or a jet turbine-blade fan.

17. The fan of claim 15, wherein the internal fan is a plurality of parallel-connected or series-connected planar fans.

18. The fan of claim 1, wherein the base comprises a filter screen provided therein.