| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitter for a tire inflation pressure alarm wherein a coiled antenna is incorporated in a valve cap for improving the efficiency of the antenna. SOLUTION: This transmitter for a tire inflation pressure alarm which has a tire valve for putting air in a tire and a transmitting portion for detecting air pressure in the tire to transmit electric waves to a vehicle side, both being formed in one unit, includes a valve stem 17 for the tire valve, a transmitting portion 7 formed in one unit with the valve stem 17 and a coil incorporated valve cap 30 formed by insert molding of a metal cap 23 with a female screw on the inner face and a coil 24 conducted with the cap 23. The valve cap 30 is fixed to the end of the valve stem 17 for emitting electric waves from the coil 24. |
