Hair dryer

Abstract

A hair dryer has a casing, a switch, a blower, a mounting cylinder and multiple heating coils. 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 coils are mounted around the mounting cylinder, are arranged abreast without any overlapping or interleaved parts and connect to the switch. At least one of the heating coils is wrapped in a clockwise direction and remains of the heating coils are wrapped in a counterclockwise direction. When the hair dryer turns on, the heating coils are electrified and currents on the heating coils are in a same direction to generate opposite magnetic forces canceling out each other.

1 . A hair dryer comprising:
 a casing being hollow and having a barrel formed on the casing and having a passage defined in the barrel, a cavity defined in the casing and communicating with the passage, at least one air inlet and an air outlet defined in the casing and communicating with the cavity;   a switch mounted on the casing;   a blower mounted in the cavity in the casing and having a motor mounted in the cavity and connecting to the switch and a fan connected rotatably to the motor; and   a mounting cylinder being heat-resistant and insulating and mounted in the passage; and   multiple heating coils wrapped spirally around the mounting cylinder, arranged abreast and kept free from overlapping and interleaved parts and connecting to the switch, at least one of the heating coils wrapped in a clockwise direction and at least one of the heating coils wrapped in a counterclockwise direction;   whereby the heating coils are electrified and currents on the heating coils are in a same direction to generate opposite magnetic forces canceling out each other.   
   
   
       2 . A hair dryer comprising:
 a casing being hollow and having a barrel formed on the casing and having a passage defined in the barrel, a cavity defined in the casing and communicating with the passage, at least one air inlet and an air outlet defined in the casing and communicating with the cavity;   a switch mounted on the casing;   a blower mounted in the cavity in the casing and having a motor mounted in the cavity and connecting to the switch and a fan blade mounted pivotally on the motor; and   a mounting cylinder mounted in the passage; and   multiple heating coils wrapped spirally around the mounting cylinder in a clockwise direction, arranged abreast and kept free from overlapping and interleaved parts and connecting to the switch;   whereby the heating coils are electrified and a current on at least one of the heating coils is in a first direction and currents on remains of the heating coils is in a second direction opposite to the first direction to generate opposite magnetic forces canceling out each other.   
   
   
       3 . A hair dryer comprising:
 a casing being hollow and having a barrel formed on the casing and having a passage defined in the barrel, a cavity defined in the casing and communicating with the passage, at least one air inlet and an air outlet defined in the casing and communicating with the cavity;   a switch mounted on the casing;   a blower mounted in the cavity in the casing and having a motor mounted in the cavity and connecting to the switch and a fan blade mounted pivotally on the motor; and   a mounting cylinder mounted in the passage; and   multiple heating coils wrapped spirally around the mounting cylinder, arranged abreast and kept free from overlapping and interleaved parts, connecting to the switch and each heating coil having a first coil segment wrapped in a clockwise direction and a second coil segment formed integrally with the first coil segment and wrapped in a counterclockwise direction;   whereby the heating coils are electrified and the first and second coil segments of each heating coil generate opposite magnetic forces canceling out each other.