Diffuser

Abstract

A diffuser includes an air inlet for receiving an airflow from a hair dryer, a grille having a plurality of air outlets for emitting a first part of the airflow from the diffuser, and a plurality of projections upstanding from the grille for contacting the hair of a user and for emitting a second part of the airflow. Each of the projections has a respective air outlet located in an end portion of the projection which is remote from the grille. The projections are divided into a first set of projections and a second set of projections arranged about the first set of projections. The air outlets of the first set of projections are arranged to emit air towards the second set of projections, and the air outlets of the second set of projections face are arranged to emit air towards the first set of projections.

Claims

1. A diffuser for attachment to an airflow outlet end of a hair dryer, the diffuser comprising: at least one air inlet for receiving an airflow from the hair dryer; a grille comprising a plurality of air outlets for emitting a first part of the airflow from the diffuser; and a plurality of projections upstanding from the grille for contacting hair of a user and for emitting a second part of the airflow, each of the projections comprising a single air outlet located in an end portion of the projection which is remote from the grille; wherein the plurality of projections comprises a first set of projections and a second set of projections arranged around the first set of projections, and wherein the single air outlets of the first set of projections are arranged to emit air towards the second set of projections, and the single air outlets of the second set of projections are arranged to emit air towards the first set of projections, and wherein a first projection of the first set of projections and a second projection of the second set of projections are aligned along a radial line extending from a longitudinal axis of the diffuser and intersecting the first and second projections, and the single air outlet of the first projection faces outwardly away from the longitudinal axis toward the second projection so that the radial line extends through a center of the single air outlet of the first projection.

2. The diffuser of claim 1, wherein the first set of projections are arranged in a first annular array, and the second set of projections are arranged in a second annular array extending around the first annular array.

3. The diffuser of claim 2, wherein the annular arrays are concentric.

4. The diffuser of claim 2, wherein, within each annular array, the projections are equally angularly spaced.

5. The diffuser of claim 1, wherein the single air outlets of the first set of projections are arranged to emit air in a radially outward direction, and the single air outlets of the second set of projections are arranged to emit air in a radially inward direction.

6. The diffuser of claim 1, wherein each of the first set of projections is arranged to emit air towards a respective one of the second set of projections.

7. The diffuser of claim 1, wherein the number of projections in the second set of projections is greater than the number of projections in the first set of projections.

8. The diffuser of claim 1, wherein, within the second set of projections, alternate projections are arranged to emit air towards a respective one of the first set of projections.

9. The diffuser of claim 1, wherein each projection has a tip which is remote from the grille and a length extending in a direction extending from the grille to the tip, the air single outlet of the projection having a length which is at least one third of the length of the projection.

10. The diffuser of claim 1, wherein the single air outlet of each projection has a length which is at least one half of the length of the projection.

11. The diffuser of claim 1, wherein the at least one air inlet is spaced from the longitudinal axis of the diffuser.

12. The diffuser of claim 1, wherein the at least one air inlet comprises at least one slot.

13. The diffuser of claim 12, wherein the at least one air inlet comprises an annular slot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred features of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

(2) FIG. 1 is a left side, front perspective view, from above, of a diffuser;

(3) FIG. 2 is a right side, rear perspective, from above, of the diffuser;

(4) FIG. 3 is a top view of the diffuser;

(5) FIG. 4 is a side view of the diffuser;

(6) FIG. 5 is a bottom view of the diffuser;

(7) FIG. 6 is a left side, front exploded view of the diffuser;

(8) FIG. 7 is a right side, rear exploded view of the diffuser;

(9) FIG. 8(a) is a top view of a baffle of the diffuser, FIG. 8(b) is a side view of the baffle, and FIG. 8(c) is a bottom view of the baffle;

(10) FIG. 9(a) is a side sectional view taken along line Y-Y in FIG. 3, FIG. 9(b) is a side sectional view taken along line Z-Z in FIG. 3, and FIG. 9(c) is a side sectional view taken along line X-X in FIG. 3; and

(11) FIG. 10 is a left side, front perspective view, from above, of an example of a hair dryer to which the diffuser may be connected.

DETAILED DESCRIPTION OF THE INVENTION

(12) FIGS. 1 to 5 are external views of a diffuser 10. The diffuser 10 comprises an air inlet 12 for receiving an airflow from an airflow outlet end of a hair dryer. With reference also to FIGS. 6 to 8, the air inlet 12 is generally annular in shape, and is in the form of a slot located at the air inlet end 14 of a baffle 16. The baffle 16 has an air outlet end 18 which is larger than the air inlet end 14, and an outwardly tapering wall 20 extending between the air inlet end 14 and the air outlet end 18. As illustrated in FIGS. 9(a) to 9(c), the tapering wall 20 of the baffle 16 defines a diffusing air chamber 22 through which the airflow passes within the diffuser 10.

(13) The baffle 16 comprises an annular air channel 24 for receiving the airflow from the air inlet 12, and from which the airflow is emitted into the air chamber 22. The air channel 24 is defined by an annular inner wall 26 and an annular outer wall 28 upstanding from the air inlet end 14 of the baffle 16, and an annular end wall 30 which extends between the inner wall 26 and the outer wall 28. The inner wall 26 comprises a first set of air outlets 32 of the air channel 24, and the outer wall 28 comprises a second set of air outlets 34 of the air channel 24. The first set of air outlets 32 is arranged to emit air radially inwardly, towards the longitudinal axis A of the diffuser 10 and towards a frustoconical projection 36 which tapers inwardly towards the longitudinal axis A. The second set of air outlets 34 is arranged to emit air radially outwardly, away from the longitudinal axis A of the diffuser 10 and towards the tapering wall 20 of the baffle 16. Each set of air outlets 32, 34 of the air channel 24 comprises six air outlets which are equally angularly arranged about the longitudinal axis A of the diffuser 10. The first set of air outlets 32 are angularly offset relative to the second set of air outlets 34 so that the first set of air outlets 32 does not overlap radially with the second set of air outlets 34.

(14) An external grille 40 is connected to the air outlet end 18 of the baffle 16. The external grille 40 is generally concave in shape. The external grille 40 comprises air outlets from which a first part of the airflow is emitted from the diffuser 10. These air outlets comprise a first array of air outlets 42 which are located in a central region of the external grille 40, and a second array of air outlets 44 which are located in a peripheral region of the external grille 40 which extends around the first array of air outlets 42. The air outlets 42, 44 have the same size and shape. Each of the air outlets 42, 44 is circular in cross-section. Each of the air outlets 42, 44 may be cylindrical in shape, but in this embodiment each of the air outlets 42, 44 is frustoconical in shape, tapering inwardly from the internal surface of the external grille 40 towards the external surface of the external grille 40. At the external surface, each of the air outlets 42, 44 has a diameter which is in the range from 0.5 to 2.5 mm, and in this embodiment is in the range from 1.5 to 1.6 mm. Each of the air outlets 42, 44 has a perimeter on the external surface of the external grille 40 which is sharper than the perimeter of the air outlet on the internal surface of the external grille 40. The perimeter of the air outlet on the internal surface is preferably rounded, and has a curvature with a radius in the range from 0.2 to 0.4 mm.

(15) Within each array, the air outlets 42, 44 are regularly spaced. The spacing between neighbouring air outlets is in the range from 0.5 to 2 mm, and in this embodiment is also in the range from 1.5 to 1.6 mm.

(16) With particular reference to FIG. 7, the first array of air outlets 42 is arranged in a first annular array which extends around the longitudinal axis A, and which generally receives airflow emitted from the first set of air outlets 32 of the air channel 24. The second array of air outlets 44 is arranged in a second annular array which surrounds, and is concentric with, the first array of air outlets 42. The second set of air outlets 44 generally receives airflow emitted from the second set of air outlets 34 of the air channel 24.

(17) An annular region 46 of the external grille 40, which is located between the arrays of air outlets 42, 44, is substantially devoid of air outlets of the external grille 40. As shown in FIGS. 3 and 6, in this embodiment the external surface of this region 46 of the external grille 40 is formed with an annular array of recesses 48 which have substantially the same size and shape as the air outlets 42, 44 but this is not essential; for example the external surface 48 of this region may be otherwise profiled or generally flat. The size of the annular region 46 is such that it occupies between 10 and 40%, preferably between 15 and 35%, of the surface area of the external surface of the external grille 40, so as to promote an even, diffused emission of air from the diffuser 10.

(18) The diffuser 10 also comprises a plurality of projections for contacting the hair of a user, and for emitting a second part of the airflow from the diffuser 10. The projections are upstanding from the external surface of the external grille 40. In this embodiment, the projections comprise a first set of projections 60 and a second set of projections 62. In this embodiment, the first set of projections 60 have the same size and shape as the second set of projections 62, but alternatively the projections may have different sizes. For example, the first set of projections 60 may be larger than the second set of projections 62.

(19) The first set of projections 60 are arranged in an annular array in the annular region 46 of the external grille 40. In this embodiment, the first set of projections 60 comprises six projections which are equally angularly spaced about the longitudinal axis A. Each of the first set of projections 60 comprises an air inlet 64 formed in the external grille 40, an air outlet 66, and a bore 68 for conveying air from the air inlet 64 to the air outlet 66. The air inlet 64 is circular in shape, and has a diameter which is greater than the diameter of the air outlets 42, 44 of the external grille 40. The air outlet 66 is in the form of an elongate side air outlet, which has a height which is approximately one half of the height of the projection 60, and a width which is smaller than the height. The air outlets 66 of the first set of projections 60 are arranged to emit air radially outwardly, away from the longitudinal axis A of the diffuser 10.

(20) The second set of projections 62 are arranged in an annular array amongst the second array of air outlets 44 of the external grille 40. In this embodiment, the second set of projections 62 comprises twelve projections which are equally angularly spaced about the longitudinal axis A. The second set of projections 62 are arranged such that each of the first set of projections 60 emits air towards a respective one of the second set of projections 62. Similar to the first set of projections 60, each of the second set of projections 62 comprises an air inlet 70 formed in the external grille 40, an air outlet 72, and a bore 74 for conveying air from the air inlet 70 to the air outlet 72. The air outlets 72 of the second set of projections 62 are arranged to emit air radially inwardly, towards the longitudinal axis A of the diffuser 10 so that alternate ones of the second set of projections 62 emit air towards a respective one of the first set of projections 60.

(21) An internal grille 80 is located within the air chamber 22. The internal grille 80 is spaced from both the air inlet 12, and the external grille 40. The internal grille 80 is in the form of a circular disc or plate which comprises an array of apertures 82 through the airflow passes between the air inlet end 14 and the air outlet end 18 of the baffle 16.

(22) The apertures 82 of the internal grille 80 have the same size and shape. The apertures 82 are generally circular in cross-section. The aperture 82 may be cylindrical in shape, but in this embodiment the apertures 82 taper inwardly from a first, inlet surface, which faces the air inlet 12, towards a second, outlet surface which faces the external grille 40. In other words, the apertures 82 are generally frustoconical in shape. At the outlet surface, the apertures 82 have a diameter in the range from 1 to 2 mm. To reduce noise as air passes through the internal grille 80, the perimeter of each aperture 82 on the outlet surface of the internal grille 80 is sharper than the perimeter of the apertures 82 on the inlet surface of the internal grille 80. The perimeters of the apertures 82 on the inlet surface are preferably rounded, and have a curvature with a radius in the range from 0.2 to 0.4 mm.

(23) As shown in FIGS. 9(a) to 9(c), the periphery of the internal grille 80 is supported by a ledge 84 formed on the internal surface of the tapering wall 20 of the baffle 16. The ledge 84 is located generally midway between the air inlet end 14 and the air outlet end 18 of the baffle 16.

(24) As a hot air flow passes through the diffuser 10, the temperature of the tapering wall 20 of the baffle 16 will rise. To shield the user from the tapering wall 20 of the baffle 16, the diffuser 10 further comprises an external wall 90 which surrounds the baffle 16 and the external grille 40. The external wall 90 is generally frustoconical in shape, and has a circular first end 92 and a circular second end 94 which is larger than the first end 92. As described in more detail below, the external wall 90 is connected to the air outlet end 18 of the baffle 16. The external wall 90 comprises a plurality of spacers 96 formed on the internal surface of the external wall 90, and which are connected to the baffle 16 during assembly of the diffuser 10. The spacers 96 are arranged in a circular array, and are equally angularly spaced about the longitudinal axis A of the diffuser 10. The spacers 96 serve to space the external wall 90 from the tapering wall 20 of the baffle 16 to define a second, or annular, air chamber 100 therebetween. The diffuser 10 comprises a plurality of ports which place the annular air chamber 100 in fluid communication with the ambient atmosphere. This can allow warm air to be conveyed out from the annular air chamber 100 during use of the diffuser 10, and also allow cool air to enter the annular air chamber 100 following use of the diffuser 10. Each of the ports is in the form of an annular slot located at a respective end of the annular air chamber 100. A first port 102 is located between the first end 92 of the external wall 90 and the air inlet end 14 of the baffle 16. A second port 104 is located between the second end 94 of the external wall 90 and the external grille 40.

(25) Each of the components of the diffuser 10 is formed from a plastics material, in this embodiment glass filled nylon.

(26) To assemble the diffuser 10, the internal grille 80 is first located within the baffle 16 so that the perimeter of the internal grille 80 rests on the ledge 84 of the baffle 16. The internal grille 80 comprises a central aperture 110 is positioned around the perimeter of a female connector 112 located on the end of the frustoconical projection 36 of the baffle 16. The baffle 16 is then located within the external wall 90 so that the air outlet end 18 of the baffle 16 rests on the spacers 96 of the external wall 90. The external surface of the tapering wall 20 of the baffle 16 includes an angular alignment member 114 which is received between an adjacent pair of the spacers 96 to ensure that the baffle 16 is accurately aligned with the external wall 90. The external grille 40 is then positioned on the air outlet end 18 of the baffle 16. The internal surface of the external grille 40 comprises a male connector 116 which is received by the female connector 112 of the baffle 16 as the external grille 40 is positioned on the air outlet end 18 of the baffle 16. The connectors 112, 116 includes inter-engaging alignment members, which in this embodiment are in the form of a slot formed in the perimeter of the female connector 112 for receiving a radial rib formed on the male connector 116, which angularly align the external grille 40 with the baffle 16. This connection of the external grille 40 to the baffle 16 also results in the internal grille 80 becoming sandwiched between the baffle 16 and the external grille 40.

(27) The assembly of the diffuser 10 is completed using ultrasonic welding to secure the external grille 40 to the baffle 16, and to secure the baffle 16 to the external wall 90. A first set of circumferentially spaced weld ribs 120 are upstanding from the air outlet end 18 of the baffle 16. The ribs 120 engage a planar, internal surface of an annular shelf 122 formed on the external grille 40, and which surrounds the air outlets 42, 44 of the external grille 40. A second set of circumferentially spaced weld ribs 126 are upstanding from the spacers 96 of the external wall 90. These ribs 126 engage the underside of the air outlet end 18 of the baffle 16. The ribs 120, 126 are arranged in a similar circular pattern so that each joint 126 is located directly beneath a respective one of the ribs 120. During assembly, an ultrasonic welding tool is positioned on the external surface of the shelf 122 to join the external grille 40 to the baffle 16 at the ribs 120, and simultaneously to join the baffle 16 to the external wall 90 at the ribs 126.

(28) In use, the diffuser 10 is attached to the airflow outlet end of a hair dryer. For example, the diffuser 10 may be attached to the hair dryer by a magnet 130 located at the air inlet end 14 of the baffle 16. An example of a hair dryer 140 to which the diffuser 10 may be attached is illustrated in FIG. 10. Such a hair dryer 140 is described in WO2015/001306, the contents of which are incorporated herein by reference, in which a hot airflow is emitted from an annular slot 142 located at the air outlet end 144 of the hair dryer 140. The slot 142 extends around a bore 146 of the hair dryer 140. The airflow passes through the air inlet 12 of the diffuser 10 to enter the air channel 24, and is emitted into the diffusing air chamber 22 through the air outlets 32, 34 of the air channel 24. The airflow passes through the apertures 82 of the internal grille 80 to the internal surface of the external grille 40. A first part of the airflow is emitted from the air outlets 42, 44 of the external grille 40, whereas a second part of the airflow is emitted from the air outlets 66, 72 of the projections 60, 62.

(29) In the event that water enters the air chamber 22 during use of the diffuser 10, for example through the bores 68, 74 of the projections 60, 62, the diffuser 10 comprises drainage holes for draining water from the diffuser 10 and away from the air inlet 12. The baffle 16 comprises a first annular drainage channel 150 which is located between the tapering wall 20 and the outer wall 28 of the air channel 24. The first drainage channel 150 is arranged to receive water droplets which may have passed through the internal grille 80 and run down the internal surface of the tapering wall 20. The outer wall 28 of the air channel 24 is inclined relative to the longitudinal axis A of the diffuser 10 so as to guide water incident thereon towards the first drainage channel 150. The first drainage channel 150 comprises a plurality of drainage holes 152 which are arranged to drain water into the annular air chamber 100, from which water may be expelled through the port 102.

(30) The baffle 16 also comprises a second annular drainage channel 154 which is located between the inner wall 26 of the air channel 24 and the frustoconical projection 36. The second drainage channel 154 is arranged to receive water droplets which may have passed through the internal grille 80 and run down the surface of the projection 36. The inner wall 26 of the air channel 24 is also inclined relative to the longitudinal axis A of the diffuser 10 so as to guide water incident thereon towards the second drainage channel 154. The second drainage channel 154 comprises a plurality of second drainage holes 156 which are arranged to drain water through the projection 36 and, if the diffuser 10 is connected to the hair dryer 140, into the bore 146 of the hair dryer 140. The end wall 30 of the air channel 24 prevent any water for falling directly into the air inlet 12, with any water incident thereon draining on to one of the inner wall 26 and the outer wall 28 of the air channel 24.