Abstract: A switch device (10, 10') which is responsive to various pressures is disclosed. The device (10, 10') includes a housing (18, 18') and plurality of switches (102, 104, 106, 168, 170, 172). A flexible diaphragm (40, 40') is supported external of the housing (18, 18') and has a first face adapted to face a pressure source and a second face facing an external wall (56, 56') of the housing (18, 18'). A plurality of first magnets (46, 48, 50, 182, 184, 186) are connected to the diaphragm at different locations thereon. A plurality of second magnets (108, 110, 112, 174, 176, 178) are supported in the housing and are each connected to one of the switches for activating a respective switch. Each of the second magnets is disposed adjacent one of the first magnets to form a plurality of pairs of first and second magnets whereby the motion of one of the first magnets of one of said pairs causes the second magnet of said last-mentioned pair to move and activate one of the switches to which it is connected.

Abstract: A rotary shaft position indicator and control in which a switch is housed within an enclosure sealed against dust, moisture, corrosive or explosive foreign materials and is magnetically actuated in response to rotary shaft position. In one embodiment a plurality of microswitches are disposed within a sealed switch cavity and cams are mounted on a rotatable spindle, each cam positioned to actuate a microswitch. A first annular magnet is secured to the spindle. Disposed proximate the first annular magnet and separated therefrom by a non-magnetic wall is a second annular magnet secured to the rotary shaft. The annular magnets are magnetically coupled through the non-magnetic wall such that rotation of the shaft causes the spindle to rotate, thereby actuating selected microswitches. In an alternative embodiment the microswitches are actuated magnetically by bar magnets secured to the rotary shaft and separated from the microswitches by a non-magnetic wall of the sealed housing.

Abstract: Measurement of the depth of material in a container is achieved through the use of an elongated sensor having a flexible member capable of being maintained in a collapsed condition to the extent of immersion by the material. A fluid control and measurement system in communication with a fluid passage in the sensor defined in part by the flexible member is operable to alternately force fluid into and drawn fluid from the portion of the sensor which is not maintained in a collapsed state by immersion in the material. The quantity of fluid thus measured is an indication of the extent of the sensor not yet covered by the material, and hence an indication of the depth of the material in the container.