Abstract: A rubber composition has sufficient resistance to degradation and swelling caused by a liquid such as a water-soluble coolant and also is capable of having sufficient resistance to ozone. The rubber composition contains a fluororubber not having a vinylidene fluoride structure, a nitrile rubber, a fluorine-based oil and a peroxide vulcanizing agent.

Abstract: A rubber composition has sufficient resistance to degradation and swelling caused by a liquid such as a water-soluble coolant and also is capable of having sufficient resistance to ozone. The rubber composition contains a fluororubber not having a vinylidene fluoride structure, a nitrile rubber, a fluorine-based oil and a peroxide vulcanizing agent.

Abstract: A trigger switch includes a trigger member pivotally attached to a grip member via a pivot pin and connected to an electric switch main body. By pressing and pivotally moving the trigger member, the switch main body can be actuated. To avoid inadvertent actuation of the switch main body, a lateral lock pin is passed through a slot provided in a metallic lock plate securely attached to the trigger member and a hole provided in the grip member so as to secure the trigger member immobile by engaging a large diameter portion of the lock pin in an expanded part of the slot of the metallic lock plate and release the trigger member by moving the large diameter portion out of the slot. To increase the margin of an insulation distance, the metallic lock plate is placed a certain distance away from the pivot pin.