Abstract: An electromagnetic relay wherein a force-transmitting member or actuator is carried by the armature to engage the contactor, which carries a moveable contact, such as to provide several different mechanical advantages in moving the moveable contact into firm engagement with a stationary contact. The actuator is provided with an inclined surface such that when the electromagnetic force on the armature is minimum, the actuator engages the contactor in a particular location to provide a mechanical advantage which requires minimum force in moving the moveable contact, and thereafter when the armature is within its strong magnetic force range, the inclined surface causes such actuator to engage the contactor in a different location to thereby provide maximum travel in urging the moveable contact into engagement with the stationary contact.

Abstract: An electronic instrument case formed of breakable plastic and having a section of reduced thickness which is firmly secured to the remainder of the wall of such enclosure by a retainer. Such reduced thickness section can be broken away from the remainder of the wall of the enclosure but it is held in attached relation thereto to thereby provide a "breathing" opening for such enclosure.