1. Field of the Invention
The present invention relates to an air bag device which is disposed on a steering wheel and which has a pressure-sensitive type horn switch.
2. Description of the Prior Art
Pads for the above-described type of air bag device having a pressure-sensitive type horn switch are known. In Japanese Patent Unexamined Publication No. 4-43158, a pad in which a pressure sensitive switch is insert-formed in a covering layer has been described.
Japanese Utility Model Unexamined Publication No. 4-5171 discloses a pad in which a pressure sensitive switch is disposed between a covering layer and an insert when the covering layer and the insert, which have been formed separately, are joined to each other.
However, the former type of pad has a drawback in that it is difficult to provide an accurate operation load of the pressure sensitive switch because the switch is embedded in the covering layer when the layer is formed and is thus affected by the generated pressure of the covering layer.
In the latter pad, since the pressure sensitive switch is sandwiched between the covering layer and the insert, the portion of the pad where the pressure sensitive switch is disposed has a three-layer structure consisting of the covering layer, the pressure sensitive switch and the insert, increasing the thickness thereof. Also, since the pressure sensitive switch is hidden in the middle of the assembly operation, the positioning operation of the switch is troublesome, thus deteriorating productivity.