Abstract: A system and probe for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit of the reference signal indicative of a predetermined reference material level.

Abstract: Apparatus for indicating level of material comprises a cable vertically suspended so as to contact and be surrounded by the material. The cable is suspended from a cam follower mechanism that engages a cam coupled to a motor for selectively introducing slack in the cable, such that the upper portion of the cable unsupported by the material engages and is suspended from a load cell. Circuitry is responsive to cable weight measured by the load cell for indicating level of the material. The motor comprises a rotary electric motor having a horizontal axis of rotation perpendicular to the vertical cable. The cam comprises a cam plate coupled to the motor to rotate about the motor axis and having an asymmetric periphery surrounding the axis of rotation. The cam follower mechanism comprises an arm pivotally mounted in fixed position adjacent to the cam plate and supporting a roller that engages the cam plate periphery.

Abstract: A conveying screw having a tubular helical flight attached only at its opposite end portions to a hollow conveying screw body. Heat exchange medium introduced into the hollow body is transferred along the tubular helical flight.

Abstract: A capacitance probe and method of probe manufacture for material level sensing systems and like applications. The probe includes a probe rod, a tubular guard coaxially surrounding the rod intermediate the rod ends, and insulation material formed as an integral piece in an injection molding operation surrounding the rod between the rod and guard and also surrounding and radially overlapping axially spaced ends of the tubular guard. One end of the rod and a portion of the guard intermediate its ends are exposed through the insulation material. The molded assembly is captured within a nipple or the like for mounting to a material vessel such that the exposed surfaces of the rod and guard are disposed internally of the vessel for capacitance coupling to material therewithin.

Abstract: A mixer includes an elongated flexible sleeve that is supported in a housing in a vertical orientation and has a mixing shaft extending therein with a plurality of blade holders supported on the shaft and each blade holder supports a plurality of blades. A deforming means extends around the flexible sleeve and is rotatable about a vertical axis by suitable reciprocating or rotating drive members to prevent accumulation of materials on the inner surface of the sleeve. The blade holders are preferably formed as an integral part of a mixing apparatus and each mixing blade is preferably individually supported on a holder to be infinitely adjustable and effect the mixing capabilities of the assembly. The flexible sleeve can be tensioned between upper and lower ends.

Abstract: A system and probe for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit of the reference signal indicative of a predetermined reference material level.

Abstract: Apparatus for indicating the level of flowable material in a storage bin comprising a motor mounted within a protective enclosure and coupled by a shaft to a paddle disposed within the bin to engage material contained therein. When the material reaches the level of the paddle, drag on the paddle causes the motor to rotate within the enclosure and thereby to activate switches disposed within the enclosure for indicating material level. A spring is mounted between the enclosure and the motor such that the spring urges the motor to both the switch-activating and the switch-deactivating positions in turn, and must be urged over center to permit motion of the motor in either direction between such positions.

Abstract: Apparatus for indicating a preselected condition of material in a vessel which includes a laid wire cable vertically suspended within the vessel so as to contact and be surrounded by material contained therein. The laid wire cable is suspended by a roller-type thrust bearing which permits free rotation of the cable and thus prevents torsional sheer stresses on the suspended cable end due to tension in the cable and consequent unraveling and reraveling of the cable lays. In a preferred embodiment of the invention wherein the upper end of the cable is selectively slackened and material level is determined as a function of weight of the slackened cable end unsupported by material, a spherical head is affixed to the cable to seat against and cooperate with a side-thrust washer slidably carried on the foot of a load cell for isolating the load cell from lateral cable forces due to material or component tolerance variations.

Abstract: A system for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has outputs coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. An automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit. A remote module provides facility for initiating a system-test and a system-calibrate operation, either individually or sequentially.

Abstract: A system for indicating level of material in a vessel as a function of material capacitance comprising a bridge circuit which includes a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An adjacent bridge arm includes a plurality of capacitors coupled to controlled electronic switches for selective connection into the bridge circuit. The bridge circuit is powered by an rf oscillator, and a differential amplifier is connected across the bridge circuit for detecting the balance condition of the bridge. An automatic calibration circuit includes a digital counter having outputs connected to the electronic switches. A comparator is responsive to the differential amplifier for enabling operation of the counter during a calibration mode of operation for selectively connecting the fixed capacitors into the bridge circuit until a preselected balance condition, corresponding to a preselected reference material level, is obtained.

Abstract: A rotary mold having a removable rotary mold segment of truncated sectorial shape having top, bottom, side, and end wall surfaces wherein the top arcuate surface is adapted for molding, and the generally planar bottom surface is connected to the top surface by two end walls in radial alignment with the axis of rotation defining the arcuate top surface wherein the bottom surface joining said end walls is in perpendicular alignment with one of said end walls.

Abstract: A system and probe for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit of the reference signal indicative of a predetermined reference material level.

Abstract: A capacitance probe and method of probe manufacture for material level sensing systems and like applications. The probe includes a probe rod, a tubular guard coaxially surrounding the rod intermediate the rod ends, and insulation material formed as an integral piece in an injection molding operation surrounding the rod between the rod and guard and also surrounding and radially overlapping axially spaced ends of the tubular guard. One end of the rod and a portion of the guard intermediate its ends are exposed through the insulation material. The molded assembly is captured within a nipple or the like for mounting to a material vessel such that the exposed surfaces of the rod and guard are disposed internally of the vessel for capacitance coupling to material therewithin.

Abstract: A capacitance probe and method of probe manufacture for material level sensing systems and like applications. The probe includes a probe rod, a tubular guard coaxially surrounding the rod intermediate the rod ends, and insulation material formed as an integral piece in an injection molding operation surrounding the rod between the rod and guard and also surrounding and radially overlapping axially spaced ends of the tubular guard. One end of the rod and a portion of the guard intermediate its ends are exposed through the insulation material. The molded assembly is captured within a nipple or the like for mounting to a material vessel such that the exposed surfaces of the rod and guard are disposed internally of the vessel for capacitance coupling to material therewithin.

Abstract: A system and probe for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit of the reference signal indicative of a predetermined reference material level.

Abstract: A system and probe for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit of the reference signal indicative of a predetermined reference material level.

Abstract: A system and probe for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An rf oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a function of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a predetermined level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit of the reference signal indicative of a predetermined reference material level.

Abstract: Apparatus for indicating the level of flowable material in a storage bin comprising a motor rotatably suspended by a spring within a protective enclosure and a drive shaft coupled by a ball-and-detent clutch to a paddle disposed within the bin to engage material therein. When the material reaches the level of the paddle, the drag on the paddle causes the motor to rotate within the enclosure and thereby to activate a switch disposed within the enclosure and coupled to the motor. A spring returns the motor to the switch-deactivated position when the material level decreases and the consequent drag is removed from the paddle. Electronic circuitry disposed within the housing includes field-selectable fail-safe circuitry for indicating either a high or a low material condition in the event of a power failure or the like independently of actual material level.

Abstract: A drop-weight type material level indicator apparatus, method and system wherein an optical disc rotationally coupled to an idler pulley in a modular sensor unit mounted at the top of a material storage bin generates counting pulses as a cable trained over the idler pulley lowers a drop weight. The counting pulses are fed in a remote readout unit to an up/down counter selectively for indicating in an up-counting mode of operation the ullage or head space between the sensor and material level, and in a down-counting mode of operation the level of material in the storage bin. Switches are provided for presetting the counter in the down-counting mode of operation to a value corresponding to bin height.