Did You Know...
...that the inventor of the electric motor was a blacksmith named Thomas Davenport? Described as "a brilliantly unsuccessful inventor", Davenport invented the first rotary electric motor. In 1836 he headed out -- on foot -- from his Vermont home to file a patent application at the Patent Office in Washington, D.C. By the time he got there, he had squandered away his money and couldn't afford the $30 filing fee so he turned around and went home. When he later mailed in his application with money he'd raised, the Patent office was destroyed in a fire. He did finally get credit for his invention on Feb. 5, 1837.
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 4099167 | Capacitive means for measuring the level of a liquid Electrodes are disposed on portions of a container comprising dielectric material, an electrical signal is capacitively transmitted between said electrodes, said electrical signal is shunted by the presence of a liquid in close proximity to said electrode... | 07/04/1978 |
| 4091675 | Samplers A sampler for taking samples continuously, at a rate proportional to flow, in which the head of liquid is sensed by capacitor probes and a voltage is generated for driving a stepping motor, the stepping motor being used to operate a pump controlling sampl... | 05/30/1978 |
| 4086528 | Capacitive transducers Measuring apparatus for determining a linear quantity comprising a capacitance transducer having at least one capacitance variable in accordance with changes in the dimensions of the quantity being measured, and a reference capacitor of substantially cons... | 04/25/1978 |
| 4083248 | Digital liquid-level gauging systems A liquid-level gauging system comprises a capacitive probe arranged in a liquid storage tank and electrically connected into timing circuitry of a pulse generator to render the period of the pulse output produced by the generator directly proportional to ... | 04/11/1978 |
| 4083038 | Condenser plate assembly A sensor and alarm device for sensing the level of a liquid in a non-conductive container, the device including a condenser plate assembly to be secured to the container for capacitive coupling to its liquid contents and further including an electronic ca... | 04/04/1978 |
| 4069710 | Apparatus for the capacitative measurement of the surface level of fluid media in vessels Apparatus for the capacitative measurement of the surface level of a fluid medium in a vessel comprises a probe mounted to provide a capacitance between itself and the surface, the probe being connected into one of two RC-circuits, respectively connected ... | 01/24/1978 |
| 4064753 | RF admittance measuring method and apparatus for determining the level of a conductive liquid Various probes which are adapted to measure the liquid level in a vessel including the flow rate through a channel comprise a conductive probe electrode and guard electrode means including a rear portion located between the wall of the vessel and the prob... | 12/27/1977 |
| 4058765 | General displacement sensor General resistive and capacitive circuitry for sensing and displaying liquid or powder level in a container, linear or rotational displacement of a body, ambient moisture content of the atmosphere, and similar physical quantities, using substantially the ... | 11/15/1977 |
| 4054744 | Seal for an instrument probe assembly There is disclosed an instrument probe assembly having a positive seal to prevent invasion of process fluids into the cavity of the assembly body. The instrument probe assembly comprises an elongated probe member which projects from a through passageway o... | 10/18/1977 |
| 4051431 | Apparatus for measuring rates of urine flow electrically This invention relates to apparatus for measuring the rate of flow F(t) of urine electrically using a measuring vessel whose filled volume V at any particular time is measured as a function V(t) of time t, so that the rate of flow F(t) = dV/dt of the urin... | 09/27/1977 |
| 4038871 | Liquid level gauge A gauge for monitoring the height of liquid contained in a storage tank or the like, comprising a channel-like structure having a first elongate probe element constituted as a circuit board having a conductive strip running for a substantial length therea... | 08/02/1977 |
| 4025846 | Capacitive sensor A capacitive sensor for detecting variations of an electric field surrounding the sensor and produced by an electronic circuit connected to it, resulting when the probe is approached or covered by a solid or fluid medium. A pot-shaped, metallic sensor ele... | 05/24/1977 |
| 4020691 | D.C. signal currents in capacitance gaging systems A signal transmission system responsive to A.C. signals has rectifier means arranged to receive the A.C. signals. The rectifier means are connected to first and second circuit paths so as to establish respective unidirectional currents of opposite polarit... | 05/03/1977 |
| 4021707 | Compensated probe for capacitive level measurement A capacitive probe for measuring fluid level has two electrodes, each of which forms a capacitor with a supporting conductive body. The first electrode is a vertical band which will yield a capacitive value dependent upon the dielectric constant, conducti... | 05/03/1977 |
| 4010650 | Apparatus for generating an electrical signal indicative of liquid level Apparatus for generating an electrical signal indicative of the level of a liquid stored in a reservoir. The apparatus includes first and second probes spaced from one another and extending into the reservoir. Each of the probes includes a metal electrode... | 03/08/1977 |
| 4003259 | Method and a device for capacitive level measurement Capacitive level measurement apparatus comprising two sets of interdigitated capacitive elements arranged along the vertical direction for immersion in a liquid or the like, and a switch arrangement with external connections which provide sequential measu... | 01/18/1977 |
| 4002996 | Level detector using oscillator circuit with two capacitive probes This invention relates to a device for detecting a fall of level of flowable material in a closed container by emitting an oscillation. It is electronic in nature and the circuit has an amplifier with a feed-back terminal that is connected to a feed-back ... | 01/11/1977 |
| 4001676 | Solid-state threshold detector An apparatus for providing a warning when the magnitude of a monitored parameter, such as vehicle fuel level, is within a critical range. A charge pump repeatedly charges a variable capacitor having a capacitance progressively changing with the magnitude ... | 01/04/1977 |
| 3995488 | Dielectric change sensing device A sensing head for use in the sensing of impedance changes includes a bridge circuit, a first diode and first resistor connected in series and a second diode and a second resistor connected in series. The first and second diodes are connected to a first j... | 12/07/1976 |
| 3991614 | Sealed capacitor transducer for fluid flow measurement A transducer for measuring gravital fluid flow includes a composite weir member having a downstream Palmer-Bowlus flume section and an upstream uniform channel section. A flexible sealed envelope partially filled with dielectric fluid is disposed in the b... | 11/16/1976 |
| 3988668 | Antistatic capacitance probe There is disclosed an antistatic capacitance probe including an electrically conductive gland for receipt in a port formed in the wall of a vessel for receiving a flowable material. A tubular central conductor projects axially from the gland and into the ... | 10/26/1976 |
| 3986110 | Water depth measuring device A device for use in determining the depth of water accumulating on the surface of a pathway, such as an airport runway or the like. A block of electrically insulative material is embedded in a pathway with the top surface of the block being substantially ... | 10/12/1976 |
| 3974695 | Double level gauge In an environment having two or more immiscible liquids wherein a first liquid floats on top of the second liquid, a gauging system which senses the depth of the first liquid which is floating on top of the second liquid. A float holding a capacitance pro... | 08/17/1976 |
| 3967501 | Slag level detection system Improved slag level detecting means wherein the sensing probes which generate an electrical potential across the slag metal interface are mounted beneath and in vertical alignment with the axis of the ladle trunnions to provide an accurate indication of m... | 07/06/1976 |
| 3965416 | Dielectric-constant measuring apparatus Accurate and stable measurement of the dielectric constant of a substance or a mixture of substances is achieved by the use of an oscillatory system incorporating a shorted transmission line as a delay means, to cycle the system. The substance for which t... | 06/22/1976 |
| 3964037 | Fuel tank alarm systems A fuel tank alarm system comprises three density sensors disposed at different heights within a fuel tank. An electrical density signal produced by the lowest sensor is subtracted from the corresponding signals from the upper two sensors to produce two de... | 06/15/1976 |
| 3958159 | Capacitance probe and system for precision measurement of liquid level The capacitance probe consists of a vertical insulated wire stretched taut in the tank, or other container, where liquid level is to be measured. Fittings at the top and bottom conveniently and efficiently support and tighten the wire. The system comprise... | 05/18/1976 |
| 3956760 | Liquid level gauge A device for indicating the presence or absence of liquid at a single level in a tank, comprising a sealed cylindrical housing having one end wall permanently fixed and the other end wall removable. The housing has an internal shoulder against which the r... | 05/11/1976 |
| 3952593 | Liquid level gauge A gauging apparatus for monitoring the height or level of liquid contained in a storage tank or the like. The apparatus comprises a probe device in the form of an elongate piece of insulating material carrying a first plurality of spaced-apart conducting ... | 04/27/1976 |
| 3950653 | Instrument for sensing level of granular materials A cylindrical housing contains both a circuit board and a pair of capacitive sensing electrodes. The pair of electrodes are adjacent the inside wall near an end that is to be wholly or partly covered with granular material in a container. Since an electri... | 04/13/1976 |
| 3948359 | Vehicle hydraulic shock absorber and indicating system A vehicle shock absorber and indicating system including a hydraulic shock absorber having two electrically conductive, relatively movable portions which are electrically insulated from one another to form a capacitor whose capacitance changes with changi... | 04/06/1976 |
| 3939360 | Liquid level sensor and electrode assembly therefor A system for detecting the fluid level in an intravenous bottle wherein a disposable electrode assembly, consisting of a piece of tape having upper, middle and lower electrode strips, is adhered to the bottle and connected to sensing equipment. The upper ... | 02/17/1976 |
| 3935739 | Liquid level gauging apparatus A liquid level gauge for monitoring the height of liquid in a storage tank or the like. The gauge comprises an upright conducting probe adapted to be immersed in the liquid in the tank, and an upright series of electrodes closely adjacent the probe. The l... | 02/03/1976 |
| 3935740 | Liquid level probe A capacitive probe for gauging the level of liquid within a reaction tank, or the like, in which the capacitive probe is formed by an electrode strip affixed to a pre-existing elongated member which projects into the reactor tank, wherein the tank and the... | 02/03/1976 |
| 3934475 | Capacitance type material level detector for hoppers A capacitance type material level detector for a hopper for particulate solid materials has a support that extends through an opening in a hopper sidewall to carry a detector unit for which it provides a hood. An electrically conductive sensor member of t... | 01/27/1976 |
| 3933042 | Water level gauge The invention disclosed in the specification is directed towards an impro device for measuring liquid levels and specifically provides a pair of capacitance probes, one of which is coated with a dielectric material, positioned in a stilling well which is... | 01/20/1976 |
| 3930411 | Fluid measuring device The invention relates to a device for measuring the quantity of a flow of fluid from fluid storage means such as liquefied gas. The device comprises a capacitor partially immersed in the stored fluid which includes a chamber being partially filled with th... | 01/06/1976 |
