Abstract: A differential pressure operated electrical switch construction is provided and has a housing carrying a pair of rigid terminals and an electrical switch for electrically interconnecting the terminals together under the control of an actuator that is responsive to differential pressure acting across the same. The terminals have free ends angled toward each other and the switch comprises a movable contact member and a spring operatively associated therewith for urging the contact member into bridging contact with the free ends of the terminals to thereby place the terminals in electrical contact with each other.

Abstract: A device for indicating that a sensed temperature has reached a certain selected level and method of making the same are provided, the device comprising a housing carrying an electrical switch unit for operating an indicator to one condition thereof when the switch unit is closed and to another condition thereof when the switch unit is open. The switch unit comprises a first movable contact unit and a second movable contact unit which when in contact with each other close the switch unit and when out of contact with each other open the switch unit. The first contact unit is moved relative to the second contact unit in relation to the sensed temperature. A selector unit is rotatably carried by the housing for selecting the certain level and has a setting portion operatively interconnected to the second contact unit to position the same relative to the first contact unit in relation to the selected level.

Abstract: A differential pressure operated electrical switch construction and method of making the same are provided, the construction having a housing carrying a pair of substantially straight parallel terminals and an electrical switch for electrically interconnecting the terminals together under the control of an actuator that is responsive to differential pressure acting across the same. One of the terminals has an end provided with a substantially rectangular opening passing transversely and completely therethrough and defining a substantially straight interior edge of the one terminal and the switch includes a movable switch blade having one end carried by the other of the terminals and having another end disposed in the opening for engaging against the edge to thereby place the terminals in electrical contact with each other.

Abstract: A differential pressure operated electrical switch construction is provided and has a housing carrying a pair of rigid terminals and an electrical switch for electrically interconnecting the terminals together under the control of an actuator that is responsive to differential pressure acting across the same. The terminals have free ends angled toward each other and the switch comprises a movable contact member and a spring operatively associated therewith for urging the contact member into bridging contact with the free ends of the terminals to thereby place the terminals in electrical contact with each other.

Abstract: A differential pressure operated electrical switch construction and method of making the same are provided, the construction having a housing carrying a pair of substantially straight parallel terminals and an electrical switch for electrically interconnecting the terminals together under the control of an actuator that is responsive to differential pressure acting across the same. One of the terminals has an end provided with a substantially rectangular opening passing transversely and completely therethrough and defining a substantially straight interior edge of the one terminal and the switch includes a movable switch blade having one end carried by the other of the terminals and having another end disposed in the opening for engaging against the edge to thereby place the terminals in electrical contact with each other.

Abstract: A method of making a plurality of substantially identical flexible diaphragms for control devices comprising the steps of providing a plurality of sheets of polyester film each being approximately 0.0005 to 0.0010 of an inch thick and each being a circular disc approximately 41/2 inches in diameter and forming the diaphragms from the sheets so that each diaphragm has an annular corrugation formed therein concentric with the center thereof and inboard of the outer periphery thereof, the step of forming the diaphragms comprising the steps of disposing the sheets in stacked aligned relation in a mold and compressing and heating the sheets in the mold in the stacked aligned relation thereof to substantially simultaneously heat form the corrugations in the sheets to thereby make the diaphragms substantially identical to each other.

Abstract: A control device having an actuator housing and a differential pressure responsive housing secured together so that a certain change in differential pressure in the pressure housing will cause a movable part thereof to move to a new certain position thereof and cause a lever arrangement in the actuator housing to operate an actuator therein. An actuating pin extends between the housings and has opposed ends respectively engaging the movable part of the pressure housing and the lever arrangement of the actuator housing to translate movement therebetween, the ends of the pin not being attached to the movable part and lever arrangement. A tubular bearing means is secured to the pressure housing and telescopically receives the actuating pin therethrough, the tubular bearing member being in fluid communication with the pressure housing so as to provide a fluid bearing for the actuating pin.