H01H7/00—Devices for introducing a predetermined time delay between the initiation of the switching operation and the opening or closing of the contacts
H01H7/02—Devices for introducing a predetermined time delay between the initiation of the switching operation and the opening or closing of the contacts with fluid timing means
H01H7/03—Devices for introducing a predetermined time delay between the initiation of the switching operation and the opening or closing of the contacts with fluid timing means with dash-pots