US 5,183,983 AGranted

Flow switch assembly for fluid flow monitoring

AssigneeDwyer Instruments, Inc.

InventorDavid G. Knop

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Abstract

A basic housing for a fluid flow monitoring assembly comprising a sensing leakproof elongate hollow body formed from a non-magnetic, metallic material and pivotally mounting internally of same a vane assembly that at one end includes a vane adapted to be inserted into a fluid flow of piping, with the vane assembly being spring biased to pivot oppositely of the direction of fluid flow, about its pivot mounting, for zero or reduced fluid flow conditions, and at its other end including a permanent magnet for electrically actuating a switch mechanism; such elongate sensing body defines an open end through which the vane projects and closed a end adjacent the magnet, which elongate body adjustably mounts crosswise thereof at its closed end within the permeability of the magnet for set point adjustment purposes a novel flow switch assembly comprising a plastic housing that is also leakproof and potably mounts in hermetically sealed relation a commercially available reed type off-on switch in electrical circuit arrangement with lead wires having ends that extend from one end of such flow switch assembly, for connection in optional electrical circuiting of a variety of types, which flow switch assembly is in field adjustable and can be set so the reed switch is Normally Open or Normally Closed, with the switch assembly housing including both indicia and flanging for setting the same precisely at such Normally Open or Normally Closed positions; the switch assembly is also arranged for full removal from the unit basic housing for inspection or replacement without the need to shut down the equipment to which the monitor assembly is applied.

In a fluid flow monitoring assembly that includes an elongate sensing body adapted for crosswise application at one end thereof to and into a conduit through which the fluid to be monitored is to flow, with the sensing body being formed from non-magnetic material to define a bore extending longitudinally thereof that is open at one end thereof and that is closed at the other end thereof, and with the sensing body cross mounting at its closed end an elongate reed type off-on switch device for adjustment movement longitudinally laterally of the body between Normally Closed (NC) and Normally Open (NO) switching function positions, and with the sensing body pivotally mounting in its bore, for pivot movement in a plane that is in substantial coplanar relation to the direction of fluid flow through the conduit, a vane assembly that includes at one end of same a vane projecting from the body open end and a permanent magnet adjacent the other end of the vane assembly disposed adjacent the sensing body closed end for effecting by magnetic action the activation of the switch device to its desired switching function position, spring means mounted within the sensing body for resiliently opposing such pivotal action of the vane assembly, and means for clamping the switch device into fixed relation with the sensing body,

the improvement wherein:
the switch device comprises an elongate housing defining an elongated bore intermediate the ends thereof, a reed switch mounted in said housing bore in electrical circuit arrangement with lead wires extending from one of end of said housing, with said reed switch being disposed on the side of said housing that has a level that is closest to the path movement of the magnet on pivotal movement of the vane assembly, said side of said housing being the switch side of said housing,
said housing defining first and second stop means disposed one on either side of the sensing body for physical engagement with the sensing body, respectively, when the switch device is to be positioned to indicate the Normally Closed and Normally Open switch function positions of said reed switch, respectively,
with said reed switch being positioned longitudinally in said housing to have its Normally Closed function when said housing first stop means engages the sensing body,
and with said housing have the side of same opposite that of said switch side bearing indicia corresponding to the location of said first and second stop means.

2 more elements

Abstract

Claims7