Patent Application
20180055187
This application claims the priority of United Kingdom Application No. 1614660.7, filed Aug. 30, 2016, the entire contents of which are incorporated herein by reference.
This invention relates to a handheld appliance and in particular to a hair care appliance such as a hot styling device.
Many hand held appliances include a fan unit comprising a fan and a motor. Electric motors are becoming increasingly sophisticated and modern designs are capable of ever higher rotational speeds. One such design of electric motor is a brushless DC motor as used by the applicant in its range of handheld vacuum cleaners and which is capable of being driven at rotational speeds in the region of 100 Krpm.
The use of high speed motors in fluid-moving applications such as vacuum cleaners, fans and hair care appliances is technically attractive since a fan unit equipped with a physically small motor can nonetheless produce very high fluid flow rates.
However, particularly in the case of hand held appliances, the motor can form a significant part of the weight of the appliance and if that appliance is dropped the motor must be protected from damage and dislocation from its' housing.
One way to protect the motor is to provide a protective sleeve around the motor however any contact between this protective sleeve or motor mount and a housing provides a pathway for vibrations and noise to transfer from the motor to the housing. Thus it is advantageous to have minimal contact; however, minimal contact may not provide sufficient contact to prevent dislocation of the motor from the housing.
The invention provides a hand held appliance comprising a hand held appliance comprising a handle having an outer wall and an inner wall and a motor housed within a housing in the inner wall wherein between the motor and the housing a motor mount is provided, the motor mount comprising a flexible sleeve extending around the motor and comprising a plurality of discrete projections arranged in a row radially around the motor mount and extending towards the housing wherein the housing comprises two annular seats for supporting the motor mount within the housing and wherein the housing comprises a recess extending radially around an inner surface of the inner wall for receiving the plurality of discrete projections.
According to some aspects, the present invention seeks to find the balance between minimal contact and thus transmission of noise and provided adequate retention of the motor in the housing.
Preferably, the motor mount comprises a second row of discrete projections extending radially around the motor mount and the housing comprises a second recess extending radially around an inner surface of the inner wall for receiving the second row of discrete projections.
In a preferred embodiment, between the recess and the second recess, the inner wall is arc shaped.
Preferably, between the recess and the second recess, the inner surface of the inner wall is convex.
In a preferred embodiment, between the recess and the second recess, the inner surface of the wall bends away from the motor mount.
Preferably, the motor mount further comprises a lip seal extending radially around an outer surface of the motor mount.
In a preferred embodiment, the lip seal is disposed approximately centrally around the motor mount.
Preferably, the arc shape is sized so the lip seal engages with the inner surface of the inner wall.
In a preferred embodiment, the appliance is a hair care appliance and preferably, a hot styling device.
The invention will now be described by way of example, with reference to the accompanying drawings, of which:
Referring to
Referring to
The configuration of the sleeve 112 defines a chamber 118, into which is received a fan unit 70 comprising a motor and impeller. The fan unit 70 is received within the chamber 118 through an open end 114, 116 of the sleeve 112. The sleeve 112 is a flexible material such as a polymer so that the sleeve 112 can be pulled over the external surface of the fan unit 70, and stretched if necessary, so that an inner surface 122 of the sleeve 112 forms a tight fit around the fan unit 70, like a sock. A pair of annular internal flanges 124 extend radially inwards from the inner surface 122 of the sleeve. These flanges 124 define the extent of the chamber 118 and are adapted to retain the fan unit 70 in position with respect to the sleeve 112. Note that the inner surface 122 is smooth in this embodiment so as to conform closely to the cylindrical outer profile of the fan unit 70.
It will be appreciated that the fan unit 70 is shown schematically for simplicity and so as not to obfuscate the details of the motor mount 100. The fan unit is not central to the inventive concept and so will not be described in detail. In addition although in this embodiment the whole fan unit 70 is housed within the motor mount 70, that is not essential, the fan may be external to the motor mount 70.
One purpose of the motor mount 100 is to fit around the fan unit 70 and serve as an isolating interface between the external case of the fan unit 70 and an internal surface of an apparatus into which the fan unit is installed. To enhance the isolating characteristics of the motor mount 100, the sleeve 112 is provided with a noise attenuating means. In this embodiment, the noise attenuating means takes the form of two rows of projecting elements 132, 134 that are spaced radially around an outer surface 130 of the motor mount.
Each projecting element 132, 134 is a stud formed as right circular cones, each of which defines a sharp point, also referred to as a vertex 136, that are directed away from the sleeve 112.
The rotation of the impeller of the fan unit by the motor generates vibrations which are transferred through the motor mount 100 towards the handle 210. Depending on the appliance orientation, at least one of the annular seals 260 located between the motor mount 100 and the housing 250 is compressed under the weight of the motor housing and the fan unit 70, so that it is in sealing engagement with the seal engaging surface or flange 260. The annular seals 260 thus not only prevent the primary air flow from travelling along a path extending between the inner surface 220a of the housing 250 and the outer surface 100a of the motor mount 100, but also reduces the transmission of these vibrations to the flange 260 and thus to the r handle 210 of the hairdryer 10. The presence of the projecting elements 134, 136 between the motor mount 100 and the housing 250 inhibits the transmission of vibrations through sleeve 112 of the motor mount 100 to the inner wall 220a of the casing. The flexibility of the plurality of elements 134, 136 allows them to flex both axially and radially relative to the housing 250, which reduces the transmission of vibrations from the fan unit.
A second type of projecting element is a lip seal 140 which extends around the sleeve 112. Although the lip seal 140 contacts the housing over a relatively large area, the lip seal 140 is intended only to create a seal between the fan unit and the housing and is not intended to absorb radial vibration of the fan unit. Consequently, the lip seal may be configured such that the seal provides a relatively poor transmission path for radial vibration of the fan unit. In particular, the radial compliance of the seal may be greater than that of the projecting elements. Consequently, radial vibration of the fan unit relative to the housing is opposed by the projecting elements 134, 136 rather than the lip seal 140.
In this example, the lip seal 140 is located approximately centrally along the length of the sleeve 112, however the lip seal 140 may be disposed anywhere along the length of the sleeve 112 so long as it does not interfere with the functioning of the projecting elements 132, 134.
The inner wall 220 includes a housing 250 includes a pair of annular seats 260 which each extend radially inwards of the inner wall 220 and which define the location of the motor mount 100 within the housing 250. Each annular seat 260 engages with a respective end 114, 116 of the motor mount 100 and retains the motor mount 100 within the housing 250. Each annular seat 260 is provided with a flange 262 which extends radially inwards of the housing 250 and inner wall 220 and is adapted to engage with an end 114, 116 of the motor mount 100.
The motor is a relatively heavy component within the appliance 10 and is encased within a flexible motor mount 100 with minimal contact to reduce noise so, if the appliance is dropped there is not a lot of resistance to the fan unit 70 leaving the housing 250. In order to help retain the fan unit 70 within its' correct location, the housing 250 is provided with a pair of recesses 270 which extend radially around the inner surface 220a of the inner wall 220 within the housing 250. The pair of recesses are adapted to each receive one of the two rows of projecting elements 132, 134 that are spaced radially around an outer surface 130 of the motor mount 100.
The pair of recesses 270 are channels around the inner surface 220a of the inner wall 220 defined by a first flange 272 and a second flange 274 each or which is orthogonal to the longitudinal axis X-X of the appliance 10. Normally the projecting elements 132, 134 are retained with a respective one of the pair of recesses 270 between the first flange 272 and the second flange 274.
Between the pair of recesses 270, the housing 250 has a curved wall 252 and the curvature is convex or radially outwards from the motor mount and the longitudinal axis Y-Y of the motor mount 100. The curved wall 252 assists in replacing a projecting element 132, 134 within a respective recess 270 in the event that one or more of the projecting elements 132, 134 is pulled out of a respective recess 270 by a movement of the fan unit 70 with respect to the housing 250 for example if the appliance were dropped from a sufficient height.
The curved wall 252 engages with the lip seal 140 around the circumference of the motor mount 100. The lip seal 140 is of sufficient length to achieve this alternatively, the arc shape is sized so the lip seal engages with the inner surface of the inner wall.
The invention has been described in detail with respect to a hot styling device however, it is applicable to any appliance that draws in a fluid and directs the outflow of that fluid from the appliance.
The appliance can be used with or without a heater; the action of the outflow of fluid at high velocity has a drying effect.
The fluid that flows through the appliance is generally air, but may be a different combination of gases or gas and can include additives to improve performance of the appliance or the impact the appliance has on an object the output is directed at for example, hair and the styling of that hair.
In the specific embodiment described above the sleeve is cylindrical. However, it should be appreciated that this is not essential to the invention and the sleeve may instead have a different cross sectional profile. Here, the profile is cylindrical so as to match the cylindrical profile of the motor casing since the sleeve should conform to its outer surface. It follows, therefore that the sleeve may have whatever profile is required to mate with an outer casing of a motor, although cylindrical motor casings are most common.
The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1614660.7 | Aug 2016 | GB | national |
