Capacitance Change-type Patents (Class 361/181)
  • Patent number: 10741064
    Abstract: A parking meter detects an object in proximity, based on a change in a proximity measurement at the meter, activates a directional sensor in response to detecting the object, receives sensor data at a meter processor from the directional sensor, wherein the received sensor data indicates a predetermined direction to the detected object relative to the meter. The parking meter determines a presence of the object, or lack thereof, in the predetermined direction based on the sensor data, and upon a positive determination of the presence of the object, stores an indication of the presence of the object along with a time of the positive determination.
    Type: Grant
    Filed: April 12, 2019
    Date of Patent: August 11, 2020
    Assignee: IPS GROUP INC.
    Inventors: Alexander Schwarz, Stephen John Hunter
  • Patent number: 10649599
    Abstract: Various embodiments of the present disclosure relate to an electronic device for using an amplifier to detect whether a user body is close to the electronic device and an operation method thereof. An electronic device according to an embodiment of the present disclosure may include: an antenna configured to be at least a part of an exterior of the electronic device; a variable element that has a capacitance in a designated range; and an amplifier connected to the variable element and configured to amplify a voltage of the variable element by a designated ratio and output an amplified voltage, wherein the capacitance of the variable element and the designated ratio may be configured so that a difference between a voltage of the antenna and the amplified voltage of the amplifier is smaller than a designated threshold value.
    Type: Grant
    Filed: June 28, 2018
    Date of Patent: May 12, 2020
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Seon-Jun Kim, Dongil Yang, Hyoseok Na
  • Patent number: 10260980
    Abstract: A pressure measurement system is provided. The system includes a pressure sensing probe extendable into a process fluid and having a pressure sensor with an electrical characteristic that varies with process fluid pressure. A mineral insulated cable has a metallic sheath with a distal end attached to the pressure sensing probe and a proximal end. The mineral insulated cable includes a plurality of conductors extending within the metallic sheath and being spaced from one another by an electrically insulative dry mineral. The proximal end of the metallic sheath is configured to be sealingly attached to a process fluid vessel.
    Type: Grant
    Filed: September 27, 2013
    Date of Patent: April 16, 2019
    Assignee: ROSEMOUNT INC.
    Inventors: Mark Stephen Schumacher, David Andrew Broden
  • Patent number: 10139439
    Abstract: A method of capacitive measurement between an object and an electrode plane includes applying an excitation signal to the resistive electrode plane, and determining a value of capacitance on the basis of a measurement of a measurement signal originating from the electrode plane. The excitation signal is a nonsinusoidal signal having at least one discontinuity. To determine the value of capacitance, the measurement signal is attenuated over a time window, this time window being the duration for which the resistivity of the electrode plane is manifested on the measurement signal in response to the at least one discontinuity.
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: November 27, 2018
    Assignee: Quickstep Technologies LLC
    Inventors: Christian Neel, Christophe Blondin
  • Patent number: 9127964
    Abstract: A parking meter detects an object in proximity, based on a change in a proximity measurement at the meter, activates a directional sensor in response to detecting the object, receives sensor data at a meter processor from the directional sensor, wherein the received sensor data indicates a predetermined direction to the detected object relative to the meter. The parking meter determines a presence of the object, or lack thereof, in the predetermined direction based on the sensor data, and upon a positive determination of the presence of the object, stores an indication of the presence of the object along with a time of the positive determination.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: September 8, 2015
    Assignee: IPS GROUP INC.
    Inventors: Alexander Schwarz, Stephen John Hunter
  • Patent number: 8373961
    Abstract: The invention relates to a coupling for a fluid line, wherein an oscillating circuit (5, 9) is present for detecting a properly closed position of an inserted part (13). A tuning device (19) is further provided, by means of which the resonant frequency of the oscillating circuit (5, 9) can be influenced such that the resonant frequency corresponds to a characteristic closure frequency only in the closed position of the insertion part (13). The proper arrangement of the insertion part (13) in the closed position can thereby be detected without contact.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: February 12, 2013
    Assignee: A. Raymond et Cie
    Inventors: Heinz Kück, André Bülau, Volker Mayer, Marc Schober, Martin Kurth
  • Patent number: 8179150
    Abstract: Monitoring system in real time of the state of capacitance graded bushings of power transformers, powers reactors, current transformers, circuit breakers and similar, it is applied preferentially by power transformers; power reactors; chain transformers, circuit breakers and similar, being the system passible of accomplish the monitoring in real time of capacitance graded bushings (1), each one resulted from a capacitive “tap” to which connects a “tap” adapter (3) that, then, connects to a measuring module (4) which receives signals coming from capacitive “tap” (2) of three graded bushings (1) which form a triphase group. One or more measuring modules (4) can, if connect to an only interface man-machine module (5), by means of a serial communication (6), forming a modular system.
    Type: Grant
    Filed: March 3, 2008
    Date of Patent: May 15, 2012
    Inventor: Eduardo Pedrosa Santos
  • Patent number: 7902615
    Abstract: A micromechanical structure and a method for producing a micromechanical structure are provided, the micromechanical structure being configured for receiving and/or generating acoustic signals in a medium at least partially surrounding the structure. The structure includes a first counterelement that has first openings and essentially forms a first side of the structure, a second counterelement that has second openings and essentially forms a second side of the structure, and an essentially closed diaphragm disposed between the first counterelement and the second counterelement.
    Type: Grant
    Filed: November 14, 2006
    Date of Patent: March 8, 2011
    Assignee: Robert Bosch GmbH
    Inventors: Roman Schlosser, Stefan Weiss, Frank Fischer, Christoph Schelling
  • Patent number: 7564247
    Abstract: An operating element, in particular for a motor vehicle component, includes an actuating element that is movably supported in a carrier element and acts, in particular, on a switch element. To detect an approach of a user to the operating element, but at the same time to prevent a misdetection by a movable component, an electrically conductive sensor element of a capacitive proximity sensor and at least one shielding element are arranged in an interior space of the actuating element, the sensor element and the shielding element being connected to a printed circuit board in an electrically conducting fashion.
    Type: Grant
    Filed: June 22, 2006
    Date of Patent: July 21, 2009
    Assignee: Siemens Aktiengesellschaft
    Inventors: Frank Born, Norbert Mankel, Joerg Reinhardt, Stefan Schaefer, Dirk Wüstenbecker
  • Patent number: 7504943
    Abstract: An object detecting apparatus includes: a piezoelectric sensor including a first electrode, a piezoelectric material surrounding the first electrode, and a second electrode surrounding the piezoelectric material and provided at an outer edge portion at a side of an opening of a door for a vehicle having a door panel; a signal processing circuit measuring a potential difference between the first electrode and the second electrode; and a connecting line connecting the first electrode and the second electrode to the signal processing circuit.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: March 17, 2009
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Masayoshi Takeuchi, Takehiko Sugiura, Nobuhiro Yamauchi
  • Patent number: 7229385
    Abstract: A wearable device having a display element, display control circuitry connected to the display element; and a flexible body for supporting the display element, wherein the body is configured and sized to be secured onto a wearer, the body includes one or more components for maintaining an imparted configuration. In this way, for example, the body can be shaped into a configuration that will support the display element at a comfortable viewing angle.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: June 12, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Gary A. Freeman, David H. Freeman
  • Patent number: 7218498
    Abstract: A touch switch apparatus for detecting the presence of an object such as a human appendage, the apparatus having a touch pad, an electric field generated about the touch pad and also having a preferably integrated and local control circuit connected to the touch pad and to a controlled device. The touch switch apparatus also having at least one of an input circuit portion for providing input signals to a decision circuit, swamping capacitance, active blocking devices, peak detector circuits, and a dual connection output latch circuit portion.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: May 15, 2007
    Assignee: TouchSensor Technologies LLC
    Inventor: David W. Caldwell
  • Patent number: 7202796
    Abstract: In order to provide a triggering signal for a cable stripping device that is also capable of dealing with very thin wires, it is suggested to use a piezoelectric sensor, the output signal from which is forwarded to an electronic evaluation unit. The electronic evaluation unit then outputs a digital signal that enables the stripping process to be started safely. Various mechanical mechanisms are suggested to ensure that the digital signal is not triggered when not being touched. This problem is proposed to be solved by a low pass filter discriminating between sensor inputs by touching and vibration shock events, etc.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: April 10, 2007
    Assignee: Komax Holding AG
    Inventor: Nicolas Ruchti
  • Patent number: 7193833
    Abstract: An electric switch (1) comprising a capacity sensor circuit (2) provided with a signal input (3) arranged to be connected to an actuating line, and which is provided with a relay device (4) arranged to feed a current to a load line (7) from a power source (6) in response to a capacitive influence along said actuating line. According to the invention the signal input (3) of the sensor circuit (2) is arranged to be connected to the load line (7) in such a manner that the load line will constitute said actuating line.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: March 20, 2007
    Assignee: Aktiebolagat Electrolux
    Inventors: Lars Ake Wern, Jan Johansson
  • Patent number: 7177132
    Abstract: A technique for controlling a switching circuit includes one or more sensing circuits that generate signals based upon the presence of an actuating object and upon a randomly applied strobe signal. The generated signals are sampled and are used as a for determining the state of an output signal. The sensing circuit may generate the signals based upon capacitive coupling with the actuating object. The randomization of the sampling enhances immunity to periodic noise. Where more than one sensing circuit is included, the output of the circuits may be considered together for determining the state of the output signal, such as based upon predetermined ranges of signal levels. Signals of the sensing circuit may be sampled in the absence of the strobe to provide an indication of the relative noise level. If the noise level is determined to be elevated, the output signal may not change states.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: February 13, 2007
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Michael Lee Gasperi, David Dale Brandt, Thong T. Nguyen
  • Patent number: 6885365
    Abstract: A glass touch sensing circuit which is capable of accurately detecting a sense signal resulting from a user's touch under no influence of variations in temperature. The glass touch sensing circuit is adapted to compare the level of an output signal from a switching device, which indicates whether the user touches a touch sensor, with that of a reference signal and convert the output signal from the switching device into a wave-shaped signal in accordance with the compared result. The present glass touch sensing circuit is further adapted to determine the level of the reference signal for compensation for a variation in the output signal from the switching device with temperature. Therefore, the glass touch sensing circuit can be employed in a human body touch-based key input sensing system to provide a constant performance irrespective of a variation in temperature so as to sense a key input based on a touching operation.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: April 26, 2005
    Assignee: LG Electronics Inc.
    Inventor: Sang-Seog Kang
  • Patent number: 6442013
    Abstract: An electronic device (1), e.g. a mobile telephone having a front cover (6) and a capacitive proximity sensor, comprising: a first electrode (9; 27) and a second electrode (8; 21, 20), said first electrode having a large face (11, 12, 13; 29); and detector means connected to the first electrode (9, 27) and the second electrode (8, 21, 20) for detecting the capacitance of the first electrode relatively to the second electrode and for providing a control signal (Vprox) responsive to the capacitance. The large face (11, 12, 13; 29) of the first electrode is inclined relative to the front cover (6).
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: August 27, 2002
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Ulf Lindgren, Christian Björk
  • Patent number: 6429782
    Abstract: A detection system includes a switch device having a conductor forming part of a capacitor with variable capacitance dependent upon proximity of a person, and a detector for sensing variation in the capacitance and for generating an output signal indicating the proximity of the person relative to the conductor. The switch device further includes a retaining body adapted to mount the conductor to a door handle, the retaining body also having a mechanical switch arranged for actuation by a person gripping the handle to additionally or alternatively indicate the proximity of the person.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: August 6, 2002
    Assignee: Robert Bosch GmbH
    Inventors: Gianfranco Pavatich, Daniel Phillip Gangemi
  • Patent number: 6376939
    Abstract: A sensor apparatus and a safety apparatus which can ensure significantly enhanced safety by monitoring constantly whether the sensor apparatus is operating normally. An auxiliary electrode plate of a small area is disposed in parallel and in opposition to an electrode plate with a short distance therefrom. A switching element is turned on every second for a period of milliseconds repetitively. When the switching element is turned on under the control of a central processing unit, the auxiliary electrode plate is connected to the ground potential, as a result of which a capacitance &Dgr;C effective between the auxiliary electrode plate and the electrode plate is electrically connected in parallel with a capacitor C0 effective between the electrode plate and a machine component, resulting in that the capacitance C0 is increased by a proportion corresponding to the capacitance &Dgr;C.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: April 23, 2002
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Takashi Suzuki, Ichirou Washizaki, Shigeo Umezaki
  • Patent number: 5796183
    Abstract: A capacitive responsive electronic switching circuit comprises an oscillator providing a periodic output signal having a frequency of 50 kHz or greater, an input touch terminal defining an area for an operator provide an input by proximity and touch, and a detector circuit coupled to the oscillator for receiving the periodic output signal from the oscillator, and coupled to the input touch terminal. The detector circuit being responsive to signals from the oscillator and the presence of an operator's body capacitance to ground coupled to the touch terminal when in proximity or touched by an operator to provide a control output signal. Preferably, the oscillator provides a periodic output signal having a frequency of 800 kHz or greater. An array of touch terminals may be provided in close proximity due to the reduction in crosstalk that may result from contaminants by utilizing an oscillator outputting a signal having a frequency of 50 kHz or greater.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: August 18, 1998
    Assignee: Nartron Corporation
    Inventor: Byron Hourmand
  • Patent number: 5796355
    Abstract: A touch switch (10) having multiple states, wherein an individual's body capacitance and/or body resistance is used to change the state of the switch.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: August 18, 1998
    Assignee: Zurich Design Laboratories, Inc.
    Inventor: Thomas Smigelski
  • Patent number: 5760715
    Abstract: The padless touch sensor is used for detecting a touch at a sensing location onto a dielectric element by a user coupled to earth. The sensor comprises a conductive plate attached under the dielectric element and in registry with the sensing location. A predetermined potential is applied on the conductive plate. Simultaneously, test pulses are produced into earth. When the user touches the dielectric element at the sensing location, a potential variation in the conductive plate is produced during a test pulse due to a capacitive circuit formed between earth, the user and the sensor. No deposition of conductive pads on the dielectric element or other special processes are required. Foreign matter or objects placed directly on top of the dielectric element will not erroneously produce a touch condition.
    Type: Grant
    Filed: April 15, 1997
    Date of Patent: June 2, 1998
    Assignee: Pressenk Instruments Inc.
    Inventors: Miro Senk, Pierre Repper
  • Patent number: 5757196
    Abstract: A capacitive proximity or limit switch comprises a capacitive probe having a sensor electrode and a guard electrode. The sensor electrode is connected to an oscillator formed by a feedback system of two operational amplifiers, of which one operational amplifier is configured as a differential amplifier, the other operational amplifier as a voltage follower. The probe electrode is connected to the inverting input of the differential amplifier, in the feedback circuit of which a capacitor is provided, as a result of which the AC gain is determined. An adjustable portion of the output voltage of the differential amplifier is applied to the non-inverting input of the voltage follower, the output of which is connected to the non-inverting input of the differential amplifier to which the guard electrode is connected.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: May 26, 1998
    Assignee: Endress + Hauser GmbH + Co.
    Inventor: Gustav Wetzel
  • Patent number: 5719450
    Abstract: An electrical power controller includes an input filter, a touch logic and a power conditioner combining to control a power device coupled to an electrical load which in turn is coupled to an AC main power source. The controller includes an overload or short circuit current sensor and apparatus for disabling the electrical power coupling to the load to protect both the load and the output power device against excessive current. A visual display indicating the level of voltage applied to the load is provided. In alternate embodiments, a timer having a preprogrammed power variation profiles imposes a predetermined variation of power to the load over time.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: February 17, 1998
    Inventor: Pramod Vora
  • Patent number: 5666010
    Abstract: A safety device and a supply power controller of a machine tool providing bidirectional communication for determining whether the safety device is appropriate for the particular machine tool, and whether the safety device is properly worn. The communication means used allow to associate one safety device to a plurality of machine tools and a plurality of safety devices to one machine tool, as well as relating safety devices to a specified work zone including a plurality of machine tools.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: September 9, 1997
    Inventor: Gus Stratiotis
  • Patent number: 5621290
    Abstract: A window glass in a motor vehicle body is slidable in a vertical direction within a window frame by means of an electric motor controlled by "up" and "down" switches. The window glass slides with reference to a window guide channel. The window guide channel incorporates a metal carrier or other electrical conductor which receives the output from electrical oscillating means. If a human hand, or other part of the human body, is present within the frame of the window, when the window is open, and within a predetermined distance from the window guide channel, the resultant capacitive effect will change the output of the oscillator. This output change is detected by a detecting unit and opens a switch. This switch is connected in series with the "up" switch for the window drive motor and thus either stops the motor, if it is driving the window glass upwards, or prevents the window glass from being so driven.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: April 15, 1997
    Assignee: Draftex Industries Limited
    Inventors: Norbert Heller, Klaus Hanndorf, Alfons Stockschlager
  • Patent number: 5572205
    Abstract: A touch control system that is responsive to a user input selection includes an electrically non-conducting substrate, such as glass ceramic, and at least one capacitive-responsive touch pad on the substrate. A source signal having a primary frequency that is greater than 150 kHz, and preferably in the range of between 150 kHz and 500 kHz, is applied to one portion of the touch pad. The touch pad couples the electrical signal to another portion of the touch pad in order to develop a detection signal, which is decoded in order to determine the presence of the capacitance of a user. The decoder preferably includes a peak detector composed of a low gain circuit in order to avoid distortion of the detection signal. Greatly improved performance in the presence of liquids, such as water, on the touch pad is provided. This is especially useful when the touch pad is applied to a horizontal surface, such as a cook top, upon which liquid spills may occur.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: November 5, 1996
    Assignee: Donnelly Technology, Inc.
    Inventors: David W. Caldwell, Nicholas W. Medendorp
  • Patent number: 5554973
    Abstract: A proximity sensor of the electrostatic type has a pulse-generating circuit and first and second delay circuits which are respectively connected to an output of the pulse-generating circuit. The first and second delay circuits are of the integrating type having capacitances which are charged over time. The second delay circuit is a reference circuit and has a delay based on a fixed capacitance. The first delay circuit has its capacitance based on a capacitance of a detection electrode. The first and second delay circuits each have their respective capacitances charged or drained by constant current circuits, each moving the same amount of current. Outputs of the first and second delay circuits are each applied to a respective limiting amplifier such as a Schmitt trigger, each Schmitt trigger then has an output to input to a common phase detector. The phase detector determines the sequence of arrival of pulses generated by the first and second delay circuits.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 10, 1996
    Assignee: Seikosha Co., Ltd.
    Inventors: Kazunori Kawashima, Hajime Oda, Takahiro Miyajima
  • Patent number: 5498914
    Abstract: A capacitive sensor circuit is provided which comprises: a sensor electrode (16) forming a first plate of a sensing capacitor (14) relative to a reference terminal (10), a first (2) and a second (26) inverting Schmitt trigger having the same threshold voltages. A feedback resistor (8) provides feedback from the output (6) to the input (4) of the first trigger (2), which together with the sensing capacitor (14) forms an oscillator whose frequency depends on the magnitude of the sensing capacitor (14). The input (24) of the second trigger (26) is connected to the output of the first trigger (2) via a series resistor (22) and to the reference terminal (10) via a reference capacitor (30). The resistance values of the feedback resistor (8) and the series resistor (22) are equal. A d.c. signal will appear on the output (32) of the second trigger if the capacitance of the sensing capacitor (14) is smaller than the capacitance of the reference capacitor (30) and an a.c. signal in the opposite case.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: March 12, 1996
    Assignee: U.S. Philips Corporation
    Inventor: Jan R. De Boer
  • Patent number: 5410148
    Abstract: A switch system for an industrial machine is described which combines both optical and capacitance switches in a switch assembly. A photo-optical switch is positioned in each assembly to provide an output signal upon the introduction of a human hand into an opening formed therein, and a capacitance sensitive touch plate switch is positioned within the opening to provide an output signal upon contact by a human hand. Circuitry responds to the substantially simultaneous activation of both the optical and capacitance switches within the switch assembly and produces an output signal. Typically two of such switch assemblies are used to control power to an industrial machine.
    Type: Grant
    Filed: May 14, 1993
    Date of Patent: April 25, 1995
    Assignee: KES Corporation
    Inventors: Kenneth L. Barron, Jr., Tan-Cheng Chou, Staton Williams, Darrin Kohn
  • Patent number: 5396222
    Abstract: The present invention relates to a machine actuating system, which includes a hand actuator system which responds to the presence of at least one operator body part at a predetermined location by generating control signal and an actuator control system to actuate the machine in response to the control signal. Generally, the actuating system includes a pair of ergonomic support members, where one support member is configured and dimensioned for interactive association with the operator's left hand and the other support member is configured and dimensioned for interactive association with the operator's right hand, and a sensing system associated with each support member for sensing the presence of the operator's hands and generating the control signal.
    Type: Grant
    Filed: March 25, 1993
    Date of Patent: March 7, 1995
    Assignee: United States Surgical Corporation
    Inventors: Joseph E. Kus, Richard Markus, Ralph A. Stearns, Charles Noel, Aquin Valentino, David Cullen, Manfred Deimold
  • Patent number: 5363051
    Abstract: A capacitive type proximity sensor having substantial range and sensitivity between a machine and an intruding object in the immediate vicinity of the machine and having a steerable sensing field has an outer electrical conductor on the machine forming one electrode of a sensor capacitor, the other electrode is the object. The outer conductor is a thin sheet of conductive material with a pair (or more) of intermediate electrical conductors located between the outer conductor and the machine. The pair of intermediate electrical conductors are in close proximity to each other and together form a surface having a size substantially larger than the outer conductor to act as a shield for reducing the parasitic capacitance between the outer conductor and the machine and to steer the sensor field. The pair of intermediate conductors are thin sheets of conductive material substantially wider than the first conductor.
    Type: Grant
    Filed: November 23, 1992
    Date of Patent: November 8, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Del T. Jenstrom, Robert L. McConnell
  • Patent number: 5276294
    Abstract: The invention prioritizes elevator service by an electronic lock and key circuit which uses a pre-existing capacitive touch button, an electronic key for receiving a 10 KHz first button pulse train from the face of the capacitive touch button and modulating said capacitive touch button pulse train with a signal of a preset frequency. A modulated first pulse train is provided back to the capacitive touch button face and an electronic lock for modulating a demodulated first pulse train received at the capacitive touch button face so as to provide a high priority hall call or a car call.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: January 4, 1994
    Assignee: Otis Elevator Company
    Inventor: Vincent P. Jalbert
  • Patent number: 5235217
    Abstract: In a preferred embodiment, a capacitive switch system including two capacitive switches which must be activated nearly simultaneously to operate a piece of equipment. When one switch is touched, a timing function is activated. If a predetermined length of time lapses before the other switch is touched, the other switch will be locked out. Both switches must then be released before the activation procedure is re-initiated. The components providing timed and anti-tie-down features, are integral to the circuitry of the switches and these as well as output relays are compactly housed in the switch housings to prevent tampering and circumvention of the safety features. The sensitivity of the switches is such that they cannot be activated by liquids.
    Type: Grant
    Filed: July 24, 1991
    Date of Patent: August 10, 1993
    Assignee: ISB Ltd.
    Inventor: James Kirton
  • Patent number: 5212621
    Abstract: A control station for a machine is equipped with capacitive proximity sensors in two locations for sensing the presence of operator's hands at the locations. The sensors are enclosed in a protective housing behind exterior target surfaces forming exterior wall surfaces of the enclosure and are supplied by a voltage source. A relay in series with each sensor and the voltage source is actuated when the operators hands are both sensed. Each sensor generates an electrical field extending outwardly a predetermined distance forwardly beyond each target surface for sensing an operators hands which are outside the enclosure within the field and need not be in tactile contact with the target surfaces. Only when both hands are sensed do the relays indicate operation of the machine.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: May 18, 1993
    Assignee: CNC Retrofits, Inc.
    Inventor: Ronald L. Panter
  • Patent number: 5134259
    Abstract: A palm button switch apparatus includes a housing, a solid palm button fixedly mounted on the housing, a guard fixedly mounted on the housing and surrounding the periphery of the palm button. A bore extends through the housing and into the palm button. The bore has an open first end and a second end covered by the palm button. A proximity switch having a sensing end is mounted in the bore with the sensing end disposed in proximity with the palm button for detecting the presence of an operator's fingers on the palm button. The housing, the palm button and the guard are integrally formed as a one-piece unit from a molded plastic.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: July 28, 1992
    Inventor: Lawrence C. Page, Jr.
  • Patent number: 4950084
    Abstract: The invention relates to a capacitive sensor for the measurement, under dynamic conditions, of at least one characteristic of a turbo-machine, this sensor comprising a conductive surface intended to be fixed to the casing near a succession of rotating blades to form the first plate of a capacitor, the second plate of which consists, in succession, of each one of the ends of the rotating blades when these ends pass in proximity to this conductive surface. This sensor comprises an electrical interconnection means to connect this conductive surface to first electrical detection means for measuring the variations of the capacitance of the capacitor thus formed. According to the invention, this electrical interconnection means also constitutes a means for connecting this conductive surface to second electrical detection means for measuring the temperature of the casing in the region of fixing of the said conductive surface.
    Type: Grant
    Filed: March 16, 1989
    Date of Patent: August 21, 1990
    Assignee: U.S. Philips Corporation
    Inventors: Gilles Bailleul, Carlos Rodrigues, Samin Albijat
  • Patent number: 4937702
    Abstract: An apparatus for controlling the intensity and on/off status of an incandescent light bulb as a function of the proximity of an object to a sensing plate. The frequency of a signal is varied from a nominal value when the presence of the object is sensed. A pulse is generated having a duration proportional to the time over which the signal if varied from its nominal frequency. The duration of the generated pulse, in relation to a pulse of predetermined width, is used to control a gated oscillator. The output of the gated oscillator is counted. The count obtained is used to control the operation of a TRIAC, which in turn connects power to the incandescent bulb.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: June 26, 1990
    Assignee: Minoru Fukumitsu
    Inventor: Hideaki Kurihara
  • Patent number: 4924122
    Abstract: A proximity-switch circuit operates a main switch TH1 to pass an ac supply through an external load when a metallic object is near a coil L1 that is part of an oscillator circuit. The oscillator circuit is connected to a level detector circuit controlling the switch TH1. The circuit is powered by a power supply stage that includes a storage capacitor C7, for which the charging current is controlled by a transistor T10 and a MOSFET T11. Upon initial application of the ac supply, the level-detector circuit is overridden by a circuit that includes capacitor C3 and transistor T4 until a predetermined period of time has elapsed, so as to prevent the generation of erroneous "on" signals before the oscillator has stabilized.
    Type: Grant
    Filed: May 15, 1987
    Date of Patent: May 8, 1990
    Assignee: Square D Company
    Inventor: Geoffrey J. Harris
  • Patent number: 4887066
    Abstract: The capacitive proximity sensor for motor vehicles comprises a capacitance-measuring device for measuring the capacitance between at least one capacitor plate (1) which is fixed to the motor vehicle, on the one hand, and the environment, on the other hand, and an indicator for receiving the output signal of the measuring device.To provide a proximity sensor in which the disturbing and parasitary capacitances occurring in practice are particularly taken into account, the output signal S.sub.c of the capacitance-measuring device (5) is delivered to an amplifier (6), which is provided with a degenerative feedback loop (9) comprising a storage device (11) and a switch (10) so that the output signal (s.sub.A) of the amplifier (6) is held constant during normal travel, and the switch (10) is opened to interrupt the degenerative feedback loop (9) for a measurement. The switch is closed when the measurement has been completed.
    Type: Grant
    Filed: June 11, 1987
    Date of Patent: December 12, 1989
    Assignee: Setec Messgerate Gesellschaft m.b.H.
    Inventor: Jiri Marek
  • Patent number: 4850386
    Abstract: A monitor or sensor for sensing the moisture content of a surrounding medium comprises two electrodes connected in a detector circuit for detecting the impedance between them and producing an output signal proportional to the impedance. At least one of the electrodes is covered by a dielectric coating and the other electrode is positioned to minimize any capacitative effects between the electrodes through the surrounding medium. The detector may comprise a multivibrator with an output frequency controlled by the sensor impedance, and the output signal can be used to control the operation of watering equipment.
    Type: Grant
    Filed: January 16, 1987
    Date of Patent: July 25, 1989
    Assignee: Aquametrics, Inc.
    Inventor: Richard L. Bireley
  • Patent number: 4831279
    Abstract: A capacitive detecting circuit for detecting transient capacitive changes such as that of a person moving into proximity of a sensing element. A sensing element is coupled to a threshold level controlled amplifier supplied with relatively high frequency signals from an oscillator through a high input impedance. A detector circuit is coupled to the amplifier output to detect D.C. variations in the level control loop caused by transient capacitive changes and provide a control output signal representative of such change.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: May 16, 1989
    Assignee: Nartron Corporation
    Inventor: Ronald D. Ingraham
  • Patent number: 4812674
    Abstract: A proximity switch has at least three Hall effect magnetic field sensitive transducers mounted in a transducer housing and has at least two magnets mounted in a magnet housing. The transucers produce logic signals, and a logic circuit responsive to these logic signals activates an electrical switch only when the magnets are in a proper position relative to the transducers. The electrical switch may be used to control a machine, and the machine is not activated until the proximity switch is activated.
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: March 14, 1989
    Assignee: Square D Company
    Inventors: Horace O. Sue, Richard T. Guttman, David M. Pendley, William C. Keys
  • Patent number: 4794273
    Abstract: An electronic ON/OFF control system for use on a powered hand tool to ensure operator safety and ease of operation. The hand tool is driven either by an electric motor driven, flexible drive shaft or a source of pressurized air supplied to the hand tool through a supply line. A low power frequency is applied alternately to the hand tool and power supply line. Appropriate circuitry detects changes in the frequency of the applied signal caused by an operator grasping the hand tool and power supply line and the sequence in which the two components are grasped. If the hand tool is being grasped when the drive shaft or supply line is subsequently grasped a signal is supplied to a power control unit which actuates the power source for the hand tool. The power control unit maintains the hand tool energized after releasing of the operator's grasp on the on the power supply line and automatically de-energizes the hand tool upon the operator releasing his grasp on the hand tool.
    Type: Grant
    Filed: September 29, 1987
    Date of Patent: December 27, 1988
    Assignee: Food Industry Equipment International, Inc.
    Inventors: Timothy J. McCullough, Arvin B. Simon
  • Patent number: 4760490
    Abstract: A proximity switch device adapted to provide a contactless switching function for an electric device, such as a radio mounted in a vehicle when approached by an object, such as a driver's hand including a floating capacitance detector and an amplified oscillator circuit for converting a change in floating capacitance into a change in frequency signal, a voltage fluctuation detecting circuit for detecting an approach of the object based upon said frequency signal, and a flip-flop switch for switching on and off the electric device whenever an output signal indicating the approach of the object is produced.
    Type: Grant
    Filed: November 12, 1986
    Date of Patent: July 26, 1988
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventor: Eiji Murao
  • Patent number: 4722021
    Abstract: To detect if a tool bit, such as a drill, a saw blade, or the like, upon being worked into a wall, meets a metallic obstruction, such as a conduit, reinforcement rod, hydraulic pipe or the like, an alternating voltage, preferably between 2 and 20 kHz, is coupled through a coupling capacitor (9) to the tool bit, and current flow to the tool bit is detected by a current measurement stage (10; 31, 32) to disconnect energy to the drive motor (5), for example by disabling firing of a thyristor (15), or closing a valve of a compressed-air tool. The coupling capacitor should have a capacity small enough to provide high impedance to network power frequency, and to insure a substantial change in current being supplied to the tool bit holder, typically a chuck, if the tool bit meets a metallic object in the wall.
    Type: Grant
    Filed: October 3, 1986
    Date of Patent: January 26, 1988
    Assignee: Robert Bosch GmbH
    Inventors: Friedrich Hornung, Fritz Schadlich, Martin Gerschner, Klaus Gunther
  • Patent number: 4689492
    Abstract: A switching circuit for turning on and off an electronic instrument, an electric lamp, or other electrically powered electric or electronic circuits, by means of a single switch, and which is constructed so that when the switch is closed momentarily and opened, the switching circuit remains "on" until the switch is again momentarily operated. However, when the switch is closed for a longer time interval, the switching circuit remains "on" for so long as the switch is closed and turns "off" when the switch is opened.
    Type: Grant
    Filed: August 1, 1986
    Date of Patent: August 25, 1987
    Inventor: Donald D. Peteuil
  • Patent number: 4683381
    Abstract: In a controlled-access apparatus for agricultural food industries, means is provided within the space located between the rotary tool-holder and the edge of the opening of the vessel of the apparatus for a protection and access-control device which performs a double function, namely that of protecting the user against accidental bodily injuries and that of allowing penetration of/or access to agricultural food products or ingredients, utensils or instruments having predetermined characteristics such as zero electrical conductivity and nonmagnetic properties.
    Type: Grant
    Filed: October 4, 1984
    Date of Patent: July 28, 1987
    Assignee: Ets. Bonnet
    Inventor: Gilbert E. Dufoug
  • Patent number: 4682272
    Abstract: A wire detector for semi-automatic wire stripper which responds to capacitance changes caused by sensing a capacitive object such as an exposed wire end and includes signal processing through an oscillator and amplifier circuit providing timer control for activating a relay driver circuit for an adjustable duration time period. The wire touch sensor circuit relay driver is then coupled through a mercury wetted relay which provides electrical isolation from external (switched) voltages to an air solenoid which, when actuated, allows the pneumatic mechanism of the wire stripper to cycle through its functions of wire stripping.
    Type: Grant
    Filed: October 23, 1986
    Date of Patent: July 21, 1987
    Assignee: The Boeing Company
    Inventors: James J. Furlong, Dwayne E. Howe
  • Patent number: 4679117
    Abstract: A wire detector for semi-automatic wire stripper which responds to capacitance changes caused by sensing a capacitance object such as an exposed wire end and includes signal processing through an oscillator and amplifier circuit providing timer control for activating a relay driver circuit for an adjustable duration time period. The wire touch sensor circuit relay driver is then coupled through a mercury wetted relay which provides electrical isolation from external (switched) voltages to an air solenoid which when actuated allows the pneumatic mechanism of the wire stripper to cycle through its functions of wire stripping.
    Type: Grant
    Filed: March 14, 1986
    Date of Patent: July 7, 1987
    Assignee: The Boeing Company
    Inventors: William T. Butcher, James J. Furlong, Dwayne E. Howe, Gerald T. Snell, Calvin M. Yara