Pressure wave switch having improved contact structure and pressure

Abstract

An improved pressure switch of the pulse or pressure wave sensitive type includes a switch housing with an internal diaphragm chamber. A relief vent with a fixed orifice disk is provided in the diaphragm chamber. A diaphragm is mounted in the diaphragm chamber which includes an electrical contact mounted on and movable with the diaphragm. An adjustable contact is threaded through a tapped terminal link in the switch housing to position a contact surface on the adjustable contact adjacent to the electrical contact mounted on the diaphragm. The adjustable contact includes a slotted end. A slotted, round lock nut is threaded on the adjustable contact. To provide an electrically reliable contact, a biasing member is positioned between the round lock nut and the tapped terminal link providing a positive thread bias on the contacting threads of the adjustable contact and the terminal link. A tool for adjusting the position of the contact surface relative to the electrical contact mounted on the diaphragm is also disclosed. The tool engages and rotates the adjustable contact while maintaining the positions of the round lock nut and the terminal link stationary. By using the tool, the positive biasing force on the contacting threads does not change. The tool includes an elongated blade member extending through a coaxial tubular member. The tubular member includes a pair of fingers configured to engage the slot of the round lock but while the blade member engages and rotates the adjustable contact.