Abstract: A latch for placing within an aperture, the latch having oppositely disposed lips to fit within the aperture; one lip including a leaf spring. The spring is flexed by inserting a rod in an orifice at the extremity of the latch for inserting or removing the latch from the aperture.

Abstract: A flat electrical connector employing axially compressed helical springs for contacts. The springs float in a housing between two flanking insulative members having printed circuit contact areas to mate with each end of each spring. The connecting force required to press one insulative member against one end of each spring is minimal, and the disconnecting force is negative. The springs may power enclosing telescoping contacts that function in the same manner as the springs alone.

Abstract: A transducer switching system for, in effect, removing electrical energy from a transducer without breaking the electrical circuit. A resistor is in series with the transducer. An electro-mechanical switch shunts the resistor. The switch is within the enclosure containing the transducer. When the acoustic connector of a use-element, such as a stethoscope type headset for a listener, is inserted into the enclosure the switch is changed from its normally open state to a closed state, thereby shorting out the resistor and allowing an effective level of electrical power to operate the transducer. Two systems may be simultaneously actuated for stereophonic sound.