Patent ID: 7145443

Claim:
A transmitter for use in a tire condition monitoring apparatus in which the transmitter is mounted in a wheel of a vehicle by an automatic mounting machine, wherein the automatic mounting machine has a jig, the transmitter comprising: a measuring-transmitting portion, which measures data representing the conditions of a tire mounted on the wheel, and transmits data indicating the condition of the tire; a valve stem, which is inserted into the wheel for allowing air to flow into the tire, the valve stem having a base end; and a casing for accommodating the measuring-transmitting portion, the casing being fixed to the base end of the valve stem, the casing having a recessed engagement portion, wherein the jig of the automatic mounting machine engages with the recessed engagement portion during mounting; wherein the recessed engagement portion has a shape such that rotation of the casing relative to the jig is limited when held by the jig.