Patents Assigned to Dwyer Instruments, Inc.
  • Patent number: 4938076
    Abstract: A target fluid flow indicator gauge comprising a non-magnetic housing defining inflow and outflow ports and a cross channel including a rounded portion that is curvilinear about an axial center that is coaxial with a fluid flow central axis through the gauge, with the channel rounded portion lying in a plane that extends normally of such axial centers and functions as a conduit for the fluid flow that is to be measured, a leaf spring adjustably and cantilever mounted in an upper portion of the housing chamber and adjacent one end of the spring, which leaf spring at the other end of same is fixed to a rigid lever arm that extends diametrically across the channel rounded portion, an orifice coaxial with said axis through which the fluid flow is directed into the chamber portion and defining a throat portion of novel configuration at the downstream end thereof that opens into the channel portion, with the lever arm mounting a target in centered relation within the orifice throat portion in coplanar, close fittin
    Type: Grant
    Filed: July 17, 1989
    Date of Patent: July 3, 1990
    Assignee: Dwyer Instruments, Inc.
    Inventor: Steven O. Buchanan
  • Patent number: 4890497
    Abstract: For use in a process control current loop including an external electrical power source that is series connected to the transmitter which is in turn connected to a fixed resistance receiver (that may be in the form of a system controller, a computer, a digital readout device, or the like) that in turn is series connected to the electrical power source, with the transmitter being arranged to provide an analog display of differential pressure or pressure sensed by the instrument and also provide for transmission to the receiver of a signal in the 4-20 milliamp range that is proportional to any changes in the differential pressure or pressure sensed by the instrument.
    Type: Grant
    Filed: August 25, 1988
    Date of Patent: January 2, 1990
    Assignee: Dwyer Instruments, Inc.
    Inventor: John M. Cahill
  • Patent number: 4860583
    Abstract: An instrument probe has two sensing elements; one is a self heated thermistor that serves as the air velocity sensor, and a second sensing element in the form of a chip thermistor, that are separately but simultaneously exposed, in the use of the instrument probe, to the air flow, with the self heated thermistor and the thermistor chip are incorporated in a self regulating bridge circuit, that, when the unit is powered, generates a non-linear signal that is applied to signal processing circuitry within the unit housing to adjust same for gain and off set with the resulting signal being applied to a linearizer circuit also within the unit housing wherein the signal is electronically processed to supply the unit output signal in the familiar 4-20 milliamp range. The transmitter device is arranged to be powered by either an alternating current or direct current supply that is in the range of about 22 volts to about 28 volts.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: August 29, 1989
    Assignee: Dwyer Instruments, Inc.
    Inventor: Thomas R. Olson
  • Patent number: 4841782
    Abstract: A target fluid flow indicator gauge comprising a non-magnetic housing defining a target chamber having a rounded portion that is curvilinear about an axial center that is coaxial with a fluid flow central axis through the gauge, with the chamber rounded portion lying in a plane that extends normally of such axial centers, a leaf spring mounted in the housing chamber and adjacent one end of the spring, which leaf spring at the other end of same has fixed to a rigid lever arm that mounts a disc-like target in centered relation within the chamber portion with the housing further defining inflow and outflow fluid ports on opposite sides of and centered on the axial centers and on the target for directing fluid flow against the target and out of the chamber; the lever arm carries a driving magnet assembly adjacent the target that is magnetically coupled through an imperforate wall structure of the housing to an externally located follower magnet assembly that acts through a short lever arm to pivot an indicator po
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: June 27, 1989
    Assignee: Dwyer Instruments, Inc.
    Inventor: Steven O. Buchanan
  • Patent number: 4838090
    Abstract: A multicoil tube type pressure gauge arranged for direct drive of the gauge pointer and for safely handling overpressure in the event of Bourdon tube rupture comprising a casing of round configuration defining a planar upright main chamber, with the casing being indented rearwardly adjacent the axial center of the gauge to define a supplemental chamber, a mounting plate that is common to all the working parts of the gauge secured to the gauge casing over the supplemental chamber and mounting cantilever fashion a tubular spool journaling the gauge pointer shaft, a multicoil Bourdon tube encircling the spool having its sealed end secured to the shaft within the supplemental chamber, and a pressure connection fitting in the form of a connection block anchored to the mounting plate and having a pressure cavity to which the Bourdon tube other end is sealingly secured with its bore in communication with the fitting pressure cavity, with the Bourdon tube direct driving the gauge pointer shaft; the working parts of t
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: June 13, 1989
    Assignee: Dwyer Instruments, Inc.
    Inventor: John Hestich
  • Patent number: 4827095
    Abstract: A differential pressure switch assembly that includes a conventional snap action switch for controlling the off-on modes of operation of state of the art equipment, which assembly comprises a high pressure plate that defines the high pressure cavity and a high pressure port of restricted size therefor, a low pressure plate that defines a first subchamber of the assembly low pressure cavity and a low pressure port therefor, a diaphragm clamped between the high and low pressure plates and separating the switch assembly high and low pressure cavities, a piston mounted in the low pressure plate for movement perpendicularly of the assembly diaphragm and biased toward the diaphragm by an adjustable range spring device, the range spring of which can be adjusted to provide the set point for the switch assembly, with the range spring device being formed to dispose the range spring in a second low pressure subchamber that is in open communication with the first low pressure subchamber to form a composite low pressure c
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: May 2, 1989
    Assignee: Dwyer Instruments, Inc.
    Inventors: Stephen S. Clark, John M. Donnelly
  • Patent number: 4725700
    Abstract: An airflow switch for sensing airflow or lack of same in an air duct comprising a housing base, mounting in side-by-side relation an adjustable range spring and a single-pole double-throw snap action microswitch, with the microswitch having its actuating lever operated by a bellcrank type input lever against an adjustable spring bias applied thereto by the range spring, with the housing base having an open center across which is secured a metallic disc that forms with the base an essentially isolated chamber in which the input lever is disposed, with sealing gasketing being applied to and about the disc rim, and with the disc being formed adjacent the mid portion thereof with a cross aperture through which the shank of a vane assembly extends for securement to the bellcrank input lever for operation of the vane assembly against the range spring bias; the vane assembly includes a vane adapted to be disposed well within the duct, and the vane assembly shank is dust sealed thereabout adjacent the disc through ap
    Type: Grant
    Filed: June 29, 1987
    Date of Patent: February 16, 1988
    Assignee: Dwyer Instruments, Inc.
    Inventor: Richard S. Zoludow
  • Patent number: 4718279
    Abstract: A pressure transducer in the nature of a differential pressure transmitter including an instrument housing defining a chamber in which is mounted a sensing transducer one of several known types powered to provide a gauge signal that is to be supplied to instrumentation such as a controller or recorder, with the pressure sensing arrangement of the instrument being in the form of two oppositely coiled bourdon tubes mounted one on either side of the sensing transducer, with like ends of the tubes each mounting an output lever, which levers are respectively resiliently connected to the movable element of the transducer and in an oppositely acting manner, with the other ends of the respective tubes being separately connected to a mounting block arranged to provide for connection of the respective tubes to separate, externally located, sources of pressure fluids, and with one of the output levers being adjustable as to length for calibrating the instrument so that the action of the two tubes on the sensing transduc
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: January 12, 1988
    Assignee: Dwyer Instruments, Inc.
    Inventor: John Hestich
  • Patent number: 4631374
    Abstract: A bin level sensor that includes a diaphragm operated switch arrangement for sensing the level of material in bins, and containers, comprising a housing of disc-like configuration that is recessed on one side of same to define a diaphragm chamber over which a flexible diaphragm is secured that has a diaphragm plate applied to the inside surfacing of same and centered thereon which seats against and is centered with respect to a thrust shaft shiftably mounted in the housing; the thrust shaft includes one end against which the diaphragm plate acts and an opposite end against which is applied a swing arm that is adjustably spring biased against the indicated opposite end of the shaft and is operably associated with an off-on operating switch. The sensing device is mounted on the wall of a bin or container to expose the device diaphragm to the bulk material contained therein.
    Type: Grant
    Filed: December 6, 1985
    Date of Patent: December 23, 1986
    Assignee: Dwyer Instruments, Inc.
    Inventor: Richard S. Zoludow
  • Patent number: 4559834
    Abstract: A multipurpose flowmeter arrangement of simplified construction that may be adapted for a number of different flowmeter applications under both pressure and vacuum conditions, in the form of a one-piece molded plastic body defining a float tube, rearwardly projecting tubular mounting studs at the base and top of the float tube that are also to form the fluid connections to and from the float tube, with the flowmeter body also defining both at the base and at the top of the float tube a cylindrical valve chamber, which valve chambers are aligned with the bores of the respective mounting studs and are each defined by a forwardly projecting cylindrical wall that, for use with valve control, may have fixed to same a sleeve that has an internal left hand thread to optionally threadedly receive either a similarly externally threaded plug to seal the valve chamber in question, or a similarly externally threaded nut that has a right hand internal threading for threadedly mounting a similarly externally threaded valve
    Type: Grant
    Filed: August 30, 1984
    Date of Patent: December 24, 1985
    Assignee: Dwyer Instruments, Inc.
    Inventors: James W. Phillips, Duane M. Kobos
  • Patent number: 4537068
    Abstract: A thermal anemometer arranged to measure air velocity over a wide range of ambient temperatures and velocities, and a method of measuring such air velocity free of influence of ambient temperature, in which the anemometer comprises a probe containing two separate and distinct sensing elements, and a hand held electronic read out unit that contains sensing signal electronic processing circuitry, function control, and an analog read out meter, with the probe and read out unit being interconnected by a self coiling cable. The probe sensing elements are a self heated thermistor and a solid state temperature sensing device, that are separately but simultaneously exposed, in use of the instrument, to the air flow, with the energy consumed by the thermistor, and its resulting signal, being an indication of both the velocity of the air stream and the difference in temperature between the forced operating temperature of the thermistor and the air stream ambient temperature.
    Type: Grant
    Filed: March 10, 1983
    Date of Patent: August 27, 1985
    Assignee: Dwyer Instruments, Inc.
    Inventors: Stanley A. Wrobel, Robert G. Ashton
  • Patent number: 4385525
    Abstract: A strain gauge pressure transducer comprising a housing having an internal pressure cavity across which is mounted a flexible elastomeric diaphragm that separates high and low pressure chambers in the gauge that the housing is arranged to separately connect the sources of high and low pressure, respectively. A range spring in the form of a leaf spring is anchored to the housing cantilever fashion in the high pressure chamber and to one side of the diaphragm to dispose the live length of same, as defined by a clamp device, in overlying relation to the diaphragm, to which the leaf spring live length is connected for deflecting movement thereof by the diaphragm.
    Type: Grant
    Filed: September 18, 1981
    Date of Patent: May 31, 1983
    Assignee: Dwyer Instruments, Inc.
    Inventors: James W. Phillips, Gregory Dirks
  • Patent number: 4380173
    Abstract: A roll-up type U-tube manometer of the type disclosed in Dwyer U.S. Pat. No.
    Type: Grant
    Filed: June 12, 1981
    Date of Patent: April 19, 1983
    Assignee: Dwyer Instruments, Inc.
    Inventor: David A. Wozniak
  • Patent number: 4374475
    Abstract: A differential pressure gauge of the type comprising a controlling magnetic helix device carrying a pressure indicating pointer, the position of which is controlled by a magnet magnetically coupled to same and mounted on the free end of a helically coiled bourdon tube exposed to differential pressures within the gauge and anchored in the gauge housing at its other end for this purpose. The magnet has a planar pole face paralleling the axis of the helix and defines a magnetic axis that is normal to and intersects the helix axis. The gauge housing defines an integral one piece pressure wall that separates and physically seals the helix from the magnet and bourdon tube and defines within the gauge housing pressure cavity an operating space within which the magnet and its supporting bourdon tube are mounted and operate.
    Type: Grant
    Filed: February 9, 1981
    Date of Patent: February 22, 1983
    Assignee: Dwyer Instruments, Inc.
    Inventor: John Hestich
  • Patent number: D287456
    Type: Grant
    Filed: June 20, 1984
    Date of Patent: December 30, 1986
    Assignee: Dwyer Instruments, Inc.
    Inventor: Duane M. Kobos
  • Patent number: D287703
    Type: Grant
    Filed: June 20, 1984
    Date of Patent: January 13, 1987
    Assignee: Dwyer Instruments, Inc.
    Inventor: Duane M. Kobos
  • Patent number: D293655
    Type: Grant
    Filed: February 5, 1985
    Date of Patent: January 12, 1988
    Assignee: Dwyer Instruments, Inc.
    Inventors: James W. Phillips, Duane M. Kobos
  • Patent number: D294230
    Type: Grant
    Filed: June 11, 1987
    Date of Patent: February 16, 1988
    Assignee: Dwyer Instruments, Inc.
    Inventors: James W. Phillips, Duane M. Kobos
  • Patent number: D301018
    Type: Grant
    Filed: April 7, 1986
    Date of Patent: May 9, 1989
    Assignee: Dwyer Instruments, Inc.
    Inventor: John Hestich
  • Patent number: D316982
    Type: Grant
    Filed: October 13, 1988
    Date of Patent: May 21, 1991
    Assignee: Dwyer Instruments, Inc.
    Inventor: John Hestich