Patent Application
20100212177
1. Field of the Invention
The present invention relates to a hair dryer, and more particularly to a hand-held hair dryer that efficiently reduces the emission of the electromagnetic radiation near the air outlet by interfering the electromagnetic radiation emitted from heating coils with the electromagnetic radiation emitted from a motor.
2. Description of Related Art
With reference to
To overcome the shortcoming, the present invention provides a hair dryer to mitigate or obviate the aforementioned problem.
The main objective of the invention is to provide a hand-held hair dryer that efficiently reduces the emission of the electromagnetic radiation deriving from the heating coils when operating and is safe for use.
A hair dryer has a casing, a switch, a blower, a mounting cylinder and a heating coil. The casing is hollow and has at least one air inlet and an air outlet. The switch is mounted on the casing. The blower is mounted in the casing and connects to the switch. The mounting cylinder is heat-resistant and insulating and is mounted in the casing. The heating coil having at least one first segment and at least one second segment is mounted around the mounting cylinder, wherein the two segments are wrapped in different directions. When the hair dryer is activated, magnetic fields resulted from the electrified heating coil and the motor tend to partially cancel each other. Therefore, the electromagnetic energy near the air outlet is reduced.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
The casing (10) is hollow and has a handgrip, a barrel (12), a cavity, at least one air inlet (11) and an air outlet (13). The handgrip is formed on the casing (10). The barrel (12) is formed on the casing (10) and has a passage defined in the barrel (12) along an axis direction. The cavity is defined in the casing (10) and communicates with the passage. The at least one air inlet (11) and the air outlet (13) are defined in the casing (10) and communicate with the cavity.
The switch (20) is mounted on the handgrip and may selectively slide to different positions to control the temperature of the airflow generated by the hair dryer.
The blower is mounted in the cavity of the casing (10) and has a motor (30) and a fan (40). The motor (30) is mounted in the cavity in the casing (10) and connects to the switch (20), so the motor (30) can be turned on or off through the switch (20). The fan (40) is connected rotatably to and driven by the motor (30) and is adjacent to the at least one air inlet (11).
The mounting cylinder (50) is heat-resistant and insulating, is mounted securely in the passage in the barrel (12) and has an inside end adjacent to the at least one air inlet (11) and an outside end adjacent to the air outlet (13).
The heating coil (60) is wrapped spirally around the mounting cylinder (50), may have at least one first coil segment (61) wrapped in a clockwise direction and at least one second coil segment (62) formed integrally with the first coil segment (61) and wrapped in a counterclockwise direction.
When turning on the hair dryer to activate the motor (30), a magnetic field (31) is generated around the motor (30). When the hair dryer is turned on, the heating coil (60) is electrified with a current identified by arrows of broken lines on
With reference to
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
