Personnel Safety Or Limit Control Features Patents (Class 307/326)
  • Patent number: 6114779
    Abstract: A sub control panel for use in maintenance work has a control switch, enable switches and manipulation prohibition members. The sub control panel is configured such that the control switch is not activated unless the enable switches are being kept ON by one hand of the operator and the operator is prevented by the manipulation prohibition members from manipulating with the one hand from turning ON the enable switches. When the sub control panel is to be used, the operator must use both hands and is hindered from inserting both hands to a driven part of a machine to be subjected to maintenance work when the machine is operating.
    Type: Grant
    Filed: October 16, 1998
    Date of Patent: September 5, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshihiko Nishionji, Tomiyasu Ueda, Masato Tanino, Tadashi Tanno, Mikiya Nakata
  • Patent number: 6100607
    Abstract: A method of detecting a condition requiring connection of a user apparatus with a feeder line comprises the steps of low-voltage power supplying the user apparatus through a detection impedance (17, 17a); detecting the waveform at the ends of the detection impedance; operating connection of the user apparatus with the feeder line when the waveform at the ends of the detection impedance is distorted in a manner that has been pre-established to be caused by actuation of a command in the user apparatus and requiring full powering of same. A device in accordance with the method comprises an analysis circuit (19, 37) detecting (by comparison with sample waveforms stored in a memory (20), for example) distortion of the waveform at the ends of the impedance (17, 17a) and consequently operating powering of the user apparatus.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: August 8, 2000
    Assignee: Compact S.r.l.
    Inventors: Daniele Olivieri, Massimo Brambilla, Paolo Delgrossi
  • Patent number: 6081049
    Abstract: This invention provides a device which facilitates electrical wiring and equipment costs for electricians installing disconnect boxes, typically in the vicinity of an outside air conditioner unit. Thus, an improved disconnect box for protection of an electrician who is servicing an electrical appliance such as an outside air conditioner is provided which incorporates an integrally mounted auxiliary electric socket accessory giving the electrician a source of power for use while the electrician is safely assured that there is no power connected to the electrical appliance being serviced. The auxiliary electrical socket accessory may optionally be connected to a power line source as a full time electric plug outlet or one only accessible when the disconnect box is conditioned to disconnect power from the electrical appliance. Provisions are made for protection of the electrical socket accessory with fusing or circuit breaker protection and ground fault protected electrical input wiring to the electrical socket.
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: June 27, 2000
    Inventor: Michael L. Simmons
  • Patent number: 6069415
    Abstract: Disclosed is an overload protection device to be placed between a robot and a tool to be used by the robot to prevent damage when the tool encounters an obstacle. The overload protection device comprises a housing, a cam, and a piston. The housing includes an internal cavity and an external opening to the cavity. The cam includes a head portion retained within the cavity and a neck portion extending through the opening. The neck portion and the opening include matching conical surfaces adapted to mate with one another. The piston is disposed within the cavity and tends to urge the cam toward a home position. When the tool is displaced in the x, y, z, or rotational directions during an overload condition, the cam is displaced from the home position. The piston then urges the cam to return to the home position regardless of the direction of displacement. A single sensor is provided to detect an overload condition.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: May 30, 2000
    Assignee: ATI Industrial Automation, Inc.
    Inventors: Robert D. Little, Prasad Balakrishnan
  • Patent number: 6060796
    Abstract: The invention concerns a protective circuit for monitoring an object which can move between two end positions, for example a displaceable safety door (1) of an electric machine. This type of protective circuit has a very simple and distinct design and can consequently be produced economically. In particular, the monitoring system is designed so as to be independent of the start command. According to the invention, at least two end switches (4, 5) are provided for monitoring the end position of the object, at least one switch (18) is provided for activating a first reservoir for a first charge potential, and a multivibrator (8) is provided which is connected to a known driver bridge (9) which has relay outputs and is connected to a consumer, for example an electric machine. The multivibrator (8) is connected to a second reservoir for a second charge potential which keeps the multivibrator (8) activated for a predetermined period of time when the end switches (4, 5) are not in the "off" position.
    Type: Grant
    Filed: June 24, 1998
    Date of Patent: May 9, 2000
    Assignee: Schneider Electric SA
    Inventors: Frank Schmitz, Christoph Klees
  • Patent number: 6011328
    Abstract: An electric power lockout apparatus is provided which includes an input terminal for electrically coupling the apparatus to an electric power source and an output terminal for electrically coupling the apparatus to a device requiring electric power. The electric power lockout apparatus also has a switch that is electrically coupled between the input terminal and the output terminal. The switch is capable of assuming: (1) an open state wherein the input terminal is electrically isolated from the output terminal and (2) a closed state wherein the input terminal is electrically coupled to the output terminal. The electric power lockout apparatus further has a first lock which controls operation of the switch so that the switch cannot assume the closed state unless the first lock is unlocked at least momentarily. The electric power lockout apparatus also has a locking structure to secure the electric power lockout apparatus to the power cord of an appliance.
    Type: Grant
    Filed: April 8, 1998
    Date of Patent: January 4, 2000
    Assignee: Terry L. Smith
    Inventor: Terry L. Smith
  • Patent number: 5999395
    Abstract: A monitoring circuit which allows for the complete monitoring, at short intervals, of several signal inputs and consequently of signal outputs without having to take into account external interference, like for instance the execution time in the case of light barriers, is obtained in that the signal inputs are connected through two capacitors to at least one relay, in that the signal inputs apply a potential to the capacitors while oscillating and in that the capacitors discharge into the relays while oscillating.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: December 7, 1999
    Assignee: Schneider Electric SA
    Inventor: Christoph Klees
  • Patent number: 5952741
    Abstract: A safe external A/C adapter protecting the user against hazardous, high-voltage D/C output. High voltage is defined as any voltage in excess of 60V D/C. The adapter provides an internal remote ON/OFF circuit that automatically switches the D/C output OFF unless the output plug is seated within a mating socket disposed in an electronic device powered by the adapter. When the output plug is so seated, the hazardous voltage output is inaccessible to the user. In addition, a secondary shutdown circuit is provided that latches off the A/C input in the unlikely event that the remote ON/OFF circuit should fail. The secondary shutdown circuit is largely independent from the primary remote ON/OFF circuit, and can be implemented using control circuitry already present in the adapter. No special mechanical connectors are required.
    Type: Grant
    Filed: July 16, 1998
    Date of Patent: September 14, 1999
    Assignee: Cisco Technology, Inc.
    Inventor: Samson K. K. Toy
  • Patent number: 5932939
    Abstract: This invention provides a device which facilitates electrical wiring and equipment costs for electricians installing disconnect boxes, typically in the vicinity of an outside air conditioner unit. Thus, an improved disconnect box for protection of an electrician who is servicing an electrical appliance such as an outside air conditioner is provided which incorporates an integrally mounted auxiliary electric socket accessory giving the electrician a source of power for use while the electrician is safely assured that there is no power connected to the electrical appliance being serviced. The auxiliary electrical socket accessory may optionally be connected to a power line source as a full time electric plug outlet or one only accessible when the disconnect box is conditioned to disconnect power from the electrical appliance. Provisions are made for protection of the electrical socket accessory with fusing or circuit breaker protection and ground fault protected electrical input wiring to the electrical socket.
    Type: Grant
    Filed: July 22, 1998
    Date of Patent: August 3, 1999
    Assignees: Jeffrey S. Houk, Dominick J. Gibino
    Inventor: Michael L. Simmons
  • Patent number: 5895988
    Abstract: A safety system for electronic devices having multiple power inputs includes dedicating a different power detector to each power input and includes disabling all of the power inputs upon detection that one input has been disabled. Each of the power inputs is typically a power cord that provides electrical energy to a discrete electrical circuit. Thus, the safety system permits the electronic device to use a different power supply for each electrical circuit, while ensuring that there is no erroneous assumption that disconnecting one of the power cords will de-energize the entire electronic device. In the preferred embodiment, the paths to the power supplies are disabled by opening relay switches, with the switches that are specific to a power cord being in a logical AND arrangement.
    Type: Grant
    Filed: August 21, 1997
    Date of Patent: April 20, 1999
    Assignee: Siemens Business Communication Systems, Inc.
    Inventors: Shmuel Shaffer, William J. Beyda, Peter Kozdon
  • Patent number: 5835332
    Abstract: This invention relates to a portable grounding mat, and more particularly to a mat specifically designed to protect electrical workers by providing a zone of equi-potential. The mat comprises a flexible base to which is attached at least two conductive elements laid out in a continuous pattern.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: November 10, 1998
    Inventors: Richard White, Ted Krossa
  • Patent number: 5825170
    Abstract: The neutralizing system comprises a low impedance current transformer for detecting an alternating stray current flowing through a ground return circuit in the proximity of an animal susceptible to be subjected to this stray current and the corresponding alternating stray voltage. The current transformer has a 1:1 primary-to-secondary transformation ratio. The neutralizing device further comprises a chain of amplification responsive to the alternating stray current detected by the current transformer to produce an alternating compensating current having an amplitude and phase respectively related to the amplitude and phase of the detected alternating stray current. Finally, a magnetic coupling circuit magnetically couples the alternating compensating current to the ground return circuit in view of inducing in that ground return circuit an alternating compensating voltage adding to the alternating stray voltage to substantially cancel this stray voltage and, a consequence the stray current.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: October 20, 1998
    Assignee: Filtre-Expert
    Inventor: Michel Montreuil
  • Patent number: 5825102
    Abstract: A fail-safe circuit (10) comprises a storage battery (11) for electrical charges as well as a first charge path (12) which optionally connects the storage battery (11) to a first potential (UL). A second charge path (14) and a third charge path (15) optionally connect the storage battery (11) with a second or third potential (UE1, UE2). The first and second switching devices (16, 17), which operate as function of the first and second switching events (TA, TB), each comprise a first and second switching contact (A1, B1) in the first charge path (12) and a second switching contact (A2, B2) in the second and third charge path (14, 15). The actuation coils (LC, LD) of the third and fourth switching devices (18, 19) are in the second and third charge path (14, 15) and each have a first switching contact (C1, D1) in the first charging path (12) and a second contact (C2, C2', D2, D2').
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: October 20, 1998
    Assignee: Gebr. Schmidt Fabrik fur Feinmechanik
    Inventors: Hartmut Babiel, Konrad Mauch
  • Patent number: 5821644
    Abstract: A safety device for a passage closure, such as a garage door, having a drive, a maximum permissible load value which can be set, and a control device by which the drive can be switched off, switch-off occurring when the maximum permissible load value has been reached and a signal S.sub.2 is sent to the control device at a time T.sub.2. A sensor is disposed in the area of the leading edge of the closure. When the sensor encounters an obstacle, it emits a signal S.sub.1 to the control device at a time T.sub.1. Upon reaching the maximum permissible load, the control device determines a .DELTA.T based on T.sub.2 -T.sub.1, compares it to a preset value and if the preset value is exceeded, changes the direction of movement of the closure.
    Type: Grant
    Filed: December 7, 1993
    Date of Patent: October 13, 1998
    Inventor: Frank-Uwe Sommer
  • Patent number: 5816541
    Abstract: A method of preventing movement of a locomotive while personnel are working on the locomotive. The method includes placing the brakes of the locomotive under the control of a card reading control box, and providing personnel employed to work on the locomotive with identification cards readable by the box. Each worker inserts his or her card in the box before working on the locomotive, and the control box reads the cards and in response thereto maintains the brakes of the locomotive at full service until personnel have left the locomotive and the control box is cleared by workers again inserting their cards in the box or by a master key in the position of an engineer/operator of a locomotive.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: October 6, 1998
    Assignee: Westinghouse Air Brake Company
    Inventors: Michael J. Joyce, Jr., Frank Huchrowski, Gregory S. Balukin
  • Patent number: 5796571
    Abstract: A control device contains two electromagnets (61, 62) in a respective current supply circuit (41, 44; 42, 44) which includes a biassed switch (20, 21) having first and second output terminals (2, 4), wherein the switches are biassed towards the first output terminal (2). When the magnets are moved to an active state against a biassing force, the switch in one circuit switches from its first (2) to its second terminal (4) to which the magnet is connected. The first and second terminals (2, 4) of the two switches (20, 21) are connected crosswise, so that a control signal (S1, S2) to the first circuit will initially energize the magnet of the second circuit, and vice versa, wherein the magnet remains in an active state if switching of the switches takes place within the time period taken for one of the magnets to leave its activated state after deactivation, i.e. when the two control signals (S1, S2) are both applied within this time period.
    Type: Grant
    Filed: December 3, 1996
    Date of Patent: August 18, 1998
    Assignee: Ross Operating Valve Company
    Inventors: Uwe Wetzel, Nils Svensson
  • Patent number: 5796341
    Abstract: A safety device and an alarm system controller of a workspace providing bidirectional communication for determining whether the required safety devices are used by the work persons entering the workspace, and whether the safety devices are properly worn. The communication means used allow to associate one or more safety devices to a work person.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: August 18, 1998
    Inventor: Gus Stratiotis
  • Patent number: 5793591
    Abstract: Stray voltage reduction system for reducing electrical shocks to livestock in a farm and similar building wherein the system senses a voltage between first and second components, such as metal stall stanchion and metal water trough, of a livestock enclosure or holding area and electrically shorts the first and second components for a preset time period when a stray voltage beyond a preset trigger voltage potential difference is detected between the first and second components. The device includes a voltage sensing circuit for sensing voltage between the first and second components, a comparator, and electrical shorting circuit that can include a relay actuated switch responsive to the output of the comparator when a sensed potential difference between the first and second components equals or exceeds a preset trigger value to electrically short (switch closed by relay) the components for a time to reduce the voltage below the trigger value.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: August 11, 1998
    Assignee: Meco Corporation
    Inventors: Raymond E. Summerer, Karl T. Person
  • Patent number: 5793125
    Abstract: The add-on smart socket adaptor integrates electric facilicities and/or home appliances to be an intelligent system for the home automation. The add-on smart socket adaptor has the add-on multiple different sensors to detect the complex environmental changes as the inputs of the programmed logic to make the complex decision function to generate the output to turn on and/or turn off the multiple different home appliances and electrical facilities smoothly, separately and cooperatively. The add-on smart socket also can be built-in to integrate with the home appliances and electrical facilities to have the home automation. The add-on smart socket adaptor provides the open platform and standard for the synthesis of home automation integrated system.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: August 11, 1998
    Inventor: Min Ming Tarng
  • Patent number: 5784246
    Abstract: A safety system comprises separate safety circuits connected to a process to be safeguarded, each of which safety circuits are coupled to a data acquisition circuit via a retroaction-free element, which takes care of it that in the event of a malfunction occurring on the input of the data acquisition circuit, this malfunction will not affect the reliability and operational safety of each of the separate safety circuits.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: July 21, 1998
    Assignee: GTI Industrial Automation, Inc.
    Inventors: Hendrik Christiaan Steinz, Jan Nichlaas De Breet
  • Patent number: 5771146
    Abstract: Safety circuits with an actuating device for electrical appliances, where the actuating device is capable of being operated by means of two key buttons or switch stacks are of use in many different areas of application. In order to create a generally suitable safety circuit, which is very simple and clear and which therefore brings with it low costs, which however stands up to all safety criteria, including the avoidance of any manipulation it is proposed that the two key buttons (S1, S2) each have a break contact (s1o, s2o) and a make contact (s1s, s2s) and act in combination with an associated driver stage (2), preferably a transistor driver stage with transistors (Q1, Q2, Q3, Q4), that the driver stage has two relays (K1, K2), that an astable circuit or multivibrator (1) with an elementary frequency of about 1000 Hz for the generation of two complementary square wave signals is connected to the relays (K1, K2) via contacts (k1, k2) so that the relays (K1, K2) are dynamically switchable.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: June 23, 1998
    Assignee: Schneider Electric SA
    Inventors: Michael Schlicker, Frank Schmitz
  • Patent number: 5767977
    Abstract: An improved carriage locking system that prevents the power cord of an optical scanner from being plugged into the scanner when the optical carriage assembly of the scanner is in the locked position. The locking system may include a locking member that the user unlocks to access the power cord receptacle upon initial setup of the scanner. The locking system may also include a spring loaded locking member that latches the optical carriage assembly against movement whenever the power cord is removed from the power cord receptacle.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: June 16, 1998
    Assignee: Hewlett-Packard Co.
    Inventors: John G Thelen, Lance W Dismang
  • Patent number: 5760499
    Abstract: A safety device includes a comparator circuit includes three resistors arranged in series. An IC has a positive pole coupled to the resistors and has a negative coupled to the positive pole of another IC which has a negative pole coupled to the resistors. A signal output circuit includes a transistor having a base connected to the ICs and having a collector coupled to a relay. The relay includes two common contacts for selectively contacting with two normally closed contacts and two normally open contacts so as to supply electric power to the common contacts when an electric appliance is coupled between the common contacts.
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: June 2, 1998
    Inventor: Se-Zhou Wu
  • Patent number: 5675227
    Abstract: A safety system including two command buttons (7, 8) spaced apart from one another geographically, and obliging an operator to use both his hands to control a radiology appliance, or one hand and a foot, is completed by a protocol including, on a single button (7), a short pulse followed by a long pulse during which the maneuver is carried out.
    Type: Grant
    Filed: April 2, 1996
    Date of Patent: October 7, 1997
    Assignee: GE Medical Systems
    Inventors: Hartog Roos, Jose Garrote
  • Patent number: 5669809
    Abstract: A safety glove for use with a meat cutting machine that has a gripping roll and an elongated skinning blade utilizes a glove shell having hollow thumb and finger elements, and a hand compartment. The glove is comprised of a flexible insulation material and has a battery and wireless signal transmitter mounted thereon. First and second wires extend from the battery and the transmitter and these wires are wound around each other and have a layer of insulation on the outer surfaces thereof. The wires are embedded in close proximity to each other within the glove shell by virtue of being wound around each other so that if the glove is cut with an electroconducting instrument, such as the blade of the skinning machine, the wires will be electrically connected together.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: September 23, 1997
    Inventor: Ray T. Townsend
  • 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: 5633778
    Abstract: An infrared signal interface enables an infrared detector module to communicate with the door edge signal input of a garage door operator. The infrared signal interface has a power supply for driving the pulsed infrared detector. Pulsed signals are received by a missing pulse detector that controls a relay. The relay may be coupled to the door edge signal of the garage door operator.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: May 27, 1997
    Assignee: The Chamberlain Group, Inc.
    Inventors: James S. Chang, Russell L. Powers
  • Patent number: 5619107
    Abstract: A device for controlling an electric vehicle motor that optimally discharges a smoothing capacitor, connected to the input terminals of an inverter in accordance with the condition of an electric vehicle. The device includes a motor drive means, the smoothing capacitor connected in parallel with the motor drive means, switching means operating in connection with an operation switch operated by the vehicle operator, discharging means for discharging the smoothing capacitor, draw detecting means, and discharge restricting means. The system opens the switching means to shut off output from the battery and to discharge the smoothing capacitor when the switching means is open, but restricts discharging during a towing or drawing condition of the electric vehicle.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: April 8, 1997
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Sadao Shinohara, Masaharu Hosoda
  • Patent number: 5608291
    Abstract: In a fluorescent lamp ballast, a source of high-frequency voltage is applied directly across a series-resonant L-C circuit. The fluorescent lamp is connected in parallel with the capacitor of the L-C circuit and a voltage-limiting means is operative to prevent the series-resonant L-C circuit from overloading the voltage source during any period when the lamp is not effective in providing circuit loading. When power is initially applied to the series-resonant L-C circuit, a control means provides a short circuit across the capacitor; and, by way of a first current transformer, the resulting short circuit current is used for pre-heating the fluorescent lamp cathodes. After about 1.5 second, the control means provides for removal of the short circuit for a period of about 25 milli-seconds, thereby permitting the voltage across the capacitor to grow to a magnitude sufficient to ignite and operate the lamp.
    Type: Grant
    Filed: June 11, 1993
    Date of Patent: March 4, 1997
    Inventor: Ole K. Nilssen
  • Patent number: 5583386
    Abstract: The invention discloses a safety circuit for electrically operated devices, which turns on the device in question, based on its position and design, only if handling and posture by the operator is completely correct and proper and the circuit, moreover, is static and insensitive to outside influences due to the use of sensor switches.
    Type: Grant
    Filed: April 20, 1994
    Date of Patent: December 10, 1996
    Assignee: Pi-Patente GmbH, Entwicklung und Verwertung
    Inventors: Hans-Werner Meixner, Alexander Voit
  • Patent number: 5546263
    Abstract: A new and novel system for protecting people and property against electrical shock. It includes a number of preferred and other embodiments which have this as their goal, but which represent a number of distinctive and novel approaches to solving prior art problems. By way of example only, and without limiting the scope of this invention, these approaches include novel immersion detecting circuits, broken wire test circuits, electromechanical circuit breaking means including coil/plunger arrangements, and relay circuit breaking mechanisms cooperative with associated circuitry, all of which are able to be incorporated as a system wholly within the load (appliance) and its associated cord set (including a "plug").
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: August 13, 1996
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Richard C. Doyle, Lester Rivera
  • Patent number: 5485340
    Abstract: An electrical supply safety plug that prevents power from a mains electrical supply from being accessible to an electrical appliance unless the electrical supply safety plug is properly engaged with the socket outlets and the appliance is turned on. The electrical supply safety plug disconnects the electrical appliance in the event of current imbalance.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: January 16, 1996
    Assignee: Aditan, Inc.
    Inventor: Shimon Avitan
  • Patent number: 5465013
    Abstract: An electric field shield for non-grounded AC powered appliances is connected to a neutral return terminal of the AC power distribution system. A polarized two prong connector assures connection of the shield to neutral. By eliminating a requirement for connection of the shield to ground, shields are made available for appliances precluded from ground connection such as bedding heaters. A double pole control switch is included to eliminate E-field generation in an OFF state caused by improper wiring or the use of unpolarized intermediate connectors. The shield is insulated and a current limiting device is series connected between the shield and neutral to reduce electrical hazards.
    Type: Grant
    Filed: July 12, 1993
    Date of Patent: November 7, 1995
    Assignee: The Government of the United States of America as represented by the Secretary of the Department of Health and Human Services
    Inventors: Howard I. Bassen, John P. Casamento
  • Patent number: 5453644
    Abstract: A personal-care apparatus comprises a load (LD) and a switch (SW), which load (LD) and which switch (SW) are coupled in series between a first (1) and a second (2) supply terminal for receiving an alternating voltage, the personal-care apparatus further comprising a rectifying circuit (RC) for converting the alternating voltage into a direct voltage, and a safety circuit (SC), which is coupled between a third (3) and a fourth (4) supply terminal for receiving the direct voltage and which comprises a capacitive sensor (CS) for the detection of the presence of a part of a human body in the proximity of the personal-care apparatus, the safety circuit being adapted to control the switch (SW) in response to said detection.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: September 26, 1995
    Assignee: U.S. Philips Corporation
    Inventors: Kok K. Yap, Boon C. Ler, Lim: Swee G.
  • Patent number: 5434457
    Abstract: A foot pedal safety switch and safety circuit for industrial machines which effectively precludes accidental operation of a machine and improper repetitive cycling of a machine. The foot pedal is completely enclosed within a rigid enclosure having an entry door through which an operator's foot is inserted each time the foot pedal switch is actuated. The safety circuit includes one or more limit switches indicating the status of the access panel and triggering a timing circuit which provides a time period within which the foot pedal switch must be contacted to operate the machine. For a second operation of the machine, the operator's foot must be removed from the enclosure allowing the access panel to close. To repeat operation of the machine, the operator then places his foot again in the foot pedal through the access panel. The safety circuit is mounted within the foot pedal switch enclosure to provide a self-contained single-actuation device which can be easily incorporated into existing machinery.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: July 18, 1995
    Inventors: Harold Josephs, Ronald W. Szcesny
  • Patent number: 5426552
    Abstract: An electrical supply safety socket that prevents power from a mains electrical supply to be accessible at the outlets of the socket unless an electrical appliance plug is properly engaged with the socket outlets and the appliance is turned on. The electrical supply safety socket is comprised of both a safety circuit and a safety socket which may act together to accomplish the above-described safety function. The safety circuit and the safety socket may also be used independently so as to provide similar safety functions.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: June 20, 1995
    Assignee: Aditan, Inc.
    Inventor: Shimon Avitan
  • Patent number: 5406436
    Abstract: A new and novel system for protecting people and property against electrical shock. It includes a number of preferred and other embodiments which have this as their goal, but which represent a number of distinctive and novel approaches to solving prior art problems. By way of example only, and without limiting the scope of this invention, these approaches include novel immersion detecting circuits, broken wire test circuits, electromechanical circuit breaking means including coil/plunger arrangements, and relay circuit breaking mechanisms cooperative with associated circuitry, all of which are able to be incorporated as a system wholly within the load (appliance) and its associated cord set (including a "plug").
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: April 11, 1995
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Richard C. Doyle, Lester Rivera
  • Patent number: 5402298
    Abstract: The present invention teaches a new and novel system for protecting people and property against electrical shock. The invention includes a number of preferred and other embodiments which have this as their goal, but which represent a number of distinctive and novel approaches to solving prior art problems. By way of example only, and without limiting the scope of this invention, these approaches include novel immersion detecting circuits, broken wire test circuits, electromechanical circuit breaking means including coil/plunger arrangements, and relay circuit breaking mechanisms cooperative with associated circuitry, all of which are able to be incorporated as a system wholly within the load (appliance) and its associated cord set (including a "plug").
    Type: Grant
    Filed: October 19, 1993
    Date of Patent: March 28, 1995
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Bernard Gershen, Saul Rosenbaum, James N. Pearse
  • Patent number: 5396122
    Abstract: For a door or protective hood locking control system of a safety device with normal or excessive safety for machines, particularly machines carrying out rotational motions, a stoppage monitoring guard is disposed in the current circuit for the door locking mechanism that is operated by push-buttons. This stoppage monitoring guard is taken from a redundant, rotational motion signal evaluating system of the target installation of a rotational motion monitoring device, which is already present, and operates redundantly to monitor each axle with two rotational motion sensors so that a dedicated rotational motion sensing system can be dispensed with for the redundant operation of the door locking system.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: March 7, 1995
    Assignee: Elge Elektronik-Geratewerk GmbH & Co.
    Inventor: Gerhard Nesper
  • Patent number: 5384495
    Abstract: A door operation control system has a door opening for moving a door between open and closed positions. A door operator control circuit selectively operates the drive means to move the door between the open and closed positions. An obstruction detection device detects whether there is an obstruction in the path of the door between the open and closed positions and generates a signal in response thereto. The obstruction detection device is connected to the control circuit by wiring to permit operation of the door opener in the absence of a signal from the obstruction detection device and to prevent certain operations of the door opener in the presence of a signal from the obstruction detection device. An error detection circuit detects faults or errors in the wiring and generates a signal to prevent certain operations of the door operator when the faults or errors are detected.
    Type: Grant
    Filed: December 8, 1993
    Date of Patent: January 24, 1995
    Assignee: GMI Holdings, Inc.
    Inventors: Dennis W. Waggamon, Louis G. Whitaker
  • Patent number: 5360998
    Abstract: A series-capacitance compensated shielding circuit is located physically adjacent and parallel to a polyphase power transmission line for the purpose of partially cancelling the electromagnetic fields created by current flow through the transmission line. The shielding circuit forms a loop circuit around substantially the entire transmission line or a portion thereof, and is positioned such that a current is induced therein by the magnetic field produced by the alternating currents in the transmission line. Such induced current is tuned by the series capacitance to produce an optimized cancelling magnetic field, thus reducing the net electromagnetic fields created by the power lines along a right-of-way.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: November 1, 1994
    Assignee: General Electric Company
    Inventor: Reigh A. Walling
  • Patent number: 5353185
    Abstract: A sensing conductor (62) within an appliance housing (56) and a detection circuit (59, 60, 61, 63) preferably within the housing, cause a low resistance shorting of an appliance circuit (57, 58) in response to immersion in water, and an interrupter device (4, 5, 6, 27), preferably located in the plug (65) of the cord set, reacts to the resulting overcurrent by opening two fuses, one in each side of the line (2, 16; 3, 17). An overcurrent opens one fast acting fuse link (27) in the normally ungrounded side of the line (3, 17) and such fuse link (5) in the normally grounded neutral side of the line (2, 16). The fuse link (27) is directly assisted in opening by a spring element (4) so as to have a slight precedence in opening, over fuse link (5) which is indirectly assisted in opening by spring (4), through an insulating coupling block (6), to achieve an initially sequential but substantially overlapping and simultaneous opening, thus disconnecting both sides of the line.
    Type: Grant
    Filed: January 6, 1992
    Date of Patent: October 4, 1994
    Assignee: Rocom Electric Co. Ltd.
    Inventor: Lawrence E. Bodkin
  • Patent number: 5345138
    Abstract: A method for assuring a safe work space operates so that a work enable signal is generated only when absence of workers from the work space where the workers work in cooperation with a machine is detected. The work enable signal has a logical value of 1 corresponding to a high energy state and only this signal can initiate activation of the machine sharing the subject work space thereby assuring safe environments for workers.
    Type: Grant
    Filed: March 14, 1991
    Date of Patent: September 6, 1994
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Masao Mukaidono, Noboru Sugimoto, Koichi Futsuhara
  • Patent number: 5343124
    Abstract: A power supply is integrally combined with a power plug, and the combination is adapted to be plugged into an ordinary household electrical outlet and operable to provide a power-line-isolated output of 120 Volt RMS at a frequency of about 30 kHz. The Volt-Ampere product available from this power supply is limited to be no more than 100 Volt-Ampere. Due to the high frequency, the electric shock hazard associated with this 120 Volt/30 kHz power supply is not higher than it is for a power supply having a voltage of only 30 Volt RMS at 60 Hz. The power supply, which also has receptacle means operable to receive and hold an ordinary electric power plug, is adapted to be interposed between an ordinary household electrical outlet and the power plug of an ordinary table lamp.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: August 30, 1994
    Inventor: Ole K. Nilssen
  • Patent number: 5341266
    Abstract: A protective device for an externally powered electrical apparatus is disclosed. The protective device is designed to prevent accidental electrocution of the user if the power supply is subject to a short circuit. The protective device is an electromechanical device incorporating a device for detecting current differentials between non-ground electrical conductors, a normally closed switch in association with a fuse device, and a trigger circuit for terminating the current flow through the electrical apparatus when a short circuit is detected.
    Type: Grant
    Filed: April 12, 1993
    Date of Patent: August 23, 1994
    Assignee: Intermacom A.G.
    Inventor: Manfred Grove
  • Patent number: 5321318
    Abstract: A method and device neutralize alternating stray current flowing through a ground return circuit in the proximity of an animal susceptible to be affected by this current. The alternating stray current flowing through the ground return circuit is sensed and a signal representative of that stray current is produced. In response to this current representative signal, an alternating compensatory current is generated and injected in the ground return circuit. The alternating compensatory current has an amplitude equal to the amplitude of the sensed stray current and is out of phase with respect to that stray current by an angle of 180.degree.. Therefore, the alternating compensatory current and the alternating stray current add in the ground return circuit and substantially cancel each other whereby the stray current can no longer affect the animal.
    Type: Grant
    Filed: May 26, 1992
    Date of Patent: June 14, 1994
    Inventor: Michel Montreuil
  • Patent number: 5267116
    Abstract: What is described is an electrical safety socket arrangement, comprising live and neutral socket inlets, switches connecting the live and neutral socket inlets to respective live and neutral socket outlets, and a circuit control which operates the switches when live and neutral supply feeders are connected to the socket inlets and a circuit is completed such that the circuit is completed by the connection of an appliance across the live and neutral socket outlets.
    Type: Grant
    Filed: January 26, 1993
    Date of Patent: November 30, 1993
    Assignee: Aditan, Inc.
    Inventor: Shimon Avitan
  • Patent number: 5264739
    Abstract: A two-hand controller for preventing trigger tie-down (10) for preventing the tie-down of an activation control switch (36,38) on equipment provided with two activation control switches (36,38). The two-hand controller for preventing trigger tie-down (10) includes a power supply (20) for supplying low voltage power to the two-hand controller (10). A comparator (18) is provided for comparing a signal (166) associated with the operation of the activation controls. An optocoupler (164) is included for receiving an optical signal (168) and activating a pilot relay (118). A constant current circuit (24) is provided for regulating the magnitude of current. A logic circuit (16) is provided for processing the signals (74,76) delivered by the activation controls (36,38) for determining when the activation controls (36,38) have been activated within a selected period of time. An inverter (46) is provided to process the output of the logic circuit (16).
    Type: Grant
    Filed: October 16, 1991
    Date of Patent: November 23, 1993
    Assignee: Acraloc Corporation
    Inventor: Joseph C. Gundlach
  • Patent number: 5240438
    Abstract: An electrical or electronical motor control composed of a switch and of an electromechanical component, each chosen from a group of different types of respectively switches and electromechanical components. A switch and an electromechanical component together form a control box. In a preferred embodiment, the electromechanical component includes a universal multiple pin connector whereas the switch is provided with a complementary multiple pin connector and the connection between those connectors is such that only the appropriate pins required to produce the appropriate result for a particular switch/electromechanical component combination are activated.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: August 31, 1993
    Assignee: Telemecanique Canada Ltee
    Inventors: Rejean Desranleau, Yvan Gingras
  • 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