FIELD OF THE INVENTION

The invention relates to a cordless hair dryer.

BACKGROUND OF THE INVENTION

Hair dryers usually have an air outlet grill that serves to prevent life parts from being touched, because these life parts may carry a dangerous voltage, and because these life parts are hot.

SUMMARY OF THE INVENTION

It is, inter alia, an object of the invention to provide an improved cordless hair dryer. The invention is defined by the independent claim. Advantageous embodiments are defined in the dependent claims.

An aspect of the invention provides a cordless hair dryer comprising a battery, a fan that is electrically coupled to the battery, and a heating unit that is electrically coupled to the battery, in which an air outlet grill is arranged for preventing the heating unit from being contacted by an elongated object having a first diameter of at least 8 mm while allowing objects having a diameter smaller than the first diameter to pass. Preferably, the air outlet grill is further arranged for preventing the fan to be contacted by the elongated object having a length of at least 50 mm. Herein, the notion fan means the combination of the rotating fan blades and the motor driving the rotating fan blades. In a practical embodiment, the air outlet grill has concentric circle-shaped elements leaving openings that prevent the elongated object from passing. Advantageously, the concentric circle-shaped elements are positioned at a mutual distance less than 8 mm. Preferably, the air outlet grill is mounted to a motor mount of a motor of the fan.

Various embodiments of the invention are based on the following considerations. Air outlet grills have as a disadvantage that they hamper the airflow, which is particularly inconvenient in case of cordless hair dryers that run on batteries that inherently have a limited capacity. Especially for cordless hair dryers it thus holds that the airflow should be hampered as little as possible. Cordless hair dryers differ from hair dryers operated by a cable to the mains network (e.g. 240 V) in that in cordless hair dryers, such dangerous voltages are not present. This means that the air outlet grill of a cordless hair dryer does not need to protect users from dangerous voltages, and that it suffices to protect users from touching a hot heating unit. So, in a cordless hair dryer, all the air outlet grill needs to do is preventing fingers from reaching the heating unit, and then the openings in the air outlet grill can be much larger than before. Instead of openings having a diameter of e.g. 3 mm, openings having a diameter of 8 mm could be used, so that the airflow is hampered to a much lesser extent. What matters is that the air outlet grill prevents a standardized test probe (e.g. IEC61032 #18) having a diameter of 8.6 mm and a length of 57.9 mm from touching moving and/or hot parts when it is attempted to insert that test probe into the hair dryer from the front.

Preferably, the air outlet grill has a concave, i.e. curved shape, viz. hollow seen from the front side of the hair dryer. Thereby, the air outlet grill is positioned as close to the center and as deep as possible with intervals that are as large as possible in view of the need to prevent a user’s fingers from touching a hot heating unit, and the IEC standardized test probe from entering. This contributes to minimizing the resistance for the air flow.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Figs. 1 A and IB illustrate an embodiment of a cordless hair dryer in accordance with the present invention.

DESCRIPTION OF EMBODIMENTS

Figs. 1 A and IB show a cross-section and a front view, respectively, of a front part of a cordless hair dryer whose fan and heating unit HU are powered by a battery (not shown). The fan has a motor M that is mounted to a housing H of the cordless hair dryer by means of a motor mount MM. Thin dotted lines link the cross-section of Fig. 1 A to the front view of Fig. IB.

The cordless hair dryer has a housing H in which the heating unit HU is mounted on a mica structure Mi (shown by striped lines). The heating unit is HU removed from a front end of the housing H by a distance d, which may be 15 mm. A user’s fingers are prevented from touching the heating unit HU by an air outlet grill AOG. The air outlet grill AOG may be mounted to the housing H, the mica structure Mi, and/or the motor mount MM. In the shown example, the air outlet grill AOG is mounted to the motor mount MM and only has 2 concentric circle-shaped elements as shown in Fig. IB (this corresponds to only 4 dots in the cross-section of Fig. 1 A). This suffices to prevent an IEC standardized test probe having a diameter of 8.6 mm and a length of 57.8 mm (representing a user’s finger) from touching moving and/or hot parts when it is attempted to insert that test probe into the hair dryer from the front.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. Measures recited in mutually different dependent claims may advantageously be used in combination.