Having Lead-in Shield Patents (Class 313/626)
  • Patent number: 6362567
    Abstract: A high pressure discharge lamp comprises a ceramic tube having axial ends and forming a closed inner space which is filled with an ionizable light-emitting material and a starting gas. Non-conductive members are inserted into the respective ends of the ceramic tube. A conductive member has one end which protrudes into the inner space of the ceramic tube. The non-conductive member and the conductive member are tightly jointed with each other by a jointing means which includes at least two thermal buffer layers successively stacked between the non-conductive member and the conductive member in the axial direction of the ceramic tube. The non-conductive member, thermal buffer layers and conductive member have respective coefficients of thermal expansion which change gradually from the coefficient of thermal expansion of the non-conductive member to that of the conductive member.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: March 26, 2002
    Assignee: NGK Insulators, Ltd.
    Inventor: Norikazu Niimi
  • Patent number: 6356018
    Abstract: A short arc lamp with a high lamp sustaining voltage in which there is no crack formation in the corner areas of the faces of shrunken regions of a side tube and of cylindrical retaining bodies for upholding parts of the electrodes, even if the gas pressure is high during operation is obtained, in a short arc lamp in which arc tube has a cathode and an anode disposed opposite one another, and in which the upholding parts of the cathode and anode are inserted and held in cylindrical retaining bodies which are supported in the shrunken regions of side tubes connected to the arc tube, by intermediate layers of metal or ceramic being located between the cylindrical retaining bodies and the shrunken regions, and by the cylindrical retaining bodies and the shrunken regions not being welded to one another into a single part.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: March 12, 2002
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Youichiro Higashimoto, Yukihiro Morimoto, Yoshihiko Shinohara
  • Patent number: 6342763
    Abstract: A high frequency operation fluorescent lamp which can reduce a possibility of over-heat damage of a flare stem at the end of its life. In the lamp, a pair of intermediate lead wires are passed through the flare stem at each end of a light emitting envelope, and an insulator is provided to cover a top of the flare stem.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: January 29, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Fukushima, Yasuo Kobayashi, Soichiro Ogawa
  • Patent number: 6313582
    Abstract: A ceramic lamp in which the hermetically sealing bodies of electrically conductive cermet are sealed to hermetically sealed tube portions of the lamp vessel with a sealing material is arranged and provided with material components designed to give the hermetically sealing portions a high reliability.
    Type: Grant
    Filed: September 17, 1999
    Date of Patent: November 6, 2001
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Shouji Miyanaga, Mitsuru Ikeuchi, Kazuyuki Mori, Yukiharu Tagawa
  • Patent number: 6271627
    Abstract: A sealing body (5) of a tube lamp using a functional gradient material in which proceeding from electrically conductive areas into the vicinity of welds on one side tube (2) and in outer leads (6) oxidation is suppressed, and in which the service life of the tube lamp is prolonged. The sealing body (5) of a tube lamp consist of a functional gradient material which is formed by mixing of a dielectric material and an electrically conductive material, the mixing ratios in the longitudinal direction being different continuously or incrementally, and in which one end forms a dielectric area and the other end forms an electrically conductive area, and by at least one part of the external surface of this electrically conductive area and/or at least one part of outer lead (6) projecting from sealing body (5) being jacketed with an atmosphere shielding layer (7).
    Type: Grant
    Filed: October 6, 1998
    Date of Patent: August 7, 2001
    Assignees: Ushiodenki Kabushiki Kaisha, Toto Ltd.
    Inventors: Yukihiro Morimoto, Kazuyuki Mori, Kenichi Mituhashi, Shoji Miyanaga
  • Patent number: 6265817
    Abstract: The electric lamp comprises a lamp vessel (1) and an electric element (4). The electric element is electrically connected to the exterior via a current feed-through comprising an external current conductor (7). By covering the external current conductor with a protective coating (8) contains chromium which can react with SiO2 to form low-melting phases, the lifetime of the lamp is increased significantly.
    Type: Grant
    Filed: August 6, 1999
    Date of Patent: July 24, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Maarten W. Steinmann, Petronella C. M. Baken
  • Patent number: 6194832
    Abstract: To close off tubular ends (6a, 6b) of a metal-halide discharge vessel, a plug (11) having at least four, and preferably six or more, axially arranged layers or strata (11a-11d; 21a-21f) of a cermet, in which the metal content of the cermet of the respective layers or strata increases from the layer or stratum closest to the discharge space of the vessel to the outside. The innermost layer or stratum is directly sintered to the ceramic discharge vessel, typically of aluminum oxide, whereas the outermost layer or stratum has a metal content of such an extent that it can be welded, and is welded, to a metallic or cermet lead-through or feed-through (9, 20, 30, 35) leading through a central opening in the respective layers or strata of the plug. The outermost layer of the plug, preferably, has at least 50%, by volume, of metal, preferably of the same material as that of the lead-through in the cermet, and may even be made entirely of metal, to ensure a tight, easily made weld connection.
    Type: Grant
    Filed: June 23, 1998
    Date of Patent: February 27, 2001
    Assignee: Patent-Treuhand-Gesellschaft f. Elektrische Gluehlampen mbH
    Inventor: Stefan Juengst
  • Patent number: 6107740
    Abstract: In sealing body (6) of a tube lamp which seals side tube (3) which is connected to arc tube (2) and which securely holds upholding parts (7) of the electrodes by a shrink seal and which consists of a functional gradient material, in which an electrically conductive component and a dielectric component in the axial direction of the tube have a continuous or gradual concentration gradient, and in which one side is dielectric and the other side is electrically conductive, the object of the invention is achieved by upholding parts (7) of the electrodes being located in an opening of this functional gradient material without a gap in a shrink seal, and by the surface of the area of upholding parts (7) of the electrodes which are located in the opening of the functional gradient material being coated at least partially with thin layer (9) of a metal with a high melting point.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: August 22, 2000
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Yukihiro Morimoto, Yukiharu Tagawa, Hiromitu Matuno
  • Patent number: 5942851
    Abstract: The low pressure sodium discharge lamp has a discharge vessel (1) having pinch seals (2) through which current conductors (4) extend towards electrodes (3) inside the discharge vessel (1). The current conductors (4) each have a first glass coating (5), which extends from inside a pinch seal (2) into the discharge vessel (1) and a second lime glass coating (6) abutting the first (5) and extending to outside the discharge vessel (1). A new first sodium resistant glass coating (5), which is substantially devoid of borate, is defined.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: August 24, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Bartholomeus Filmer, Petrus M.G. Van Gennip
  • Patent number: 5905340
    Abstract: A high intensity discharge lamp with a heat treated inner electrode rod has been found to form an advantageous crack pattern. As a result seal failures have been reduced and lamp life increased.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: May 18, 1999
    Assignee: Osram Sylvania Inc.
    Inventors: Rober J. Karlotski, Timothy L. Kelly, Galina Zilberstein
  • Patent number: 5838104
    Abstract: An improved compact, white color and pulse operated high pressure sodium vapor arc discharge lamp employing a radiation sensitive getter RF flashed onto the inner surface of the outer lamp envelope has a ceramic radiation shield interposed between the arc tube and getter.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: November 17, 1998
    Assignee: General Electric Company
    Inventors: Douglas M. Rutan, Curtis E. Scott, Jeannine A. Woyansky, Katherine L. McGinnis
  • Patent number: 5757134
    Abstract: A high intensity discharge lamp has a light transmissive envelope and an arc tube located within the envelope. The arc tube contains an arc generating and sustaining medium as well as electrodes. A flare is sealed to the lamp envelope and the flare includes two electrically conductive lead-ins sealed therein, each of the lead-ins having a given diameter. A mica heat shield comprising a planar mica disc frictionally engages the lead-ins, the mica disc having a pair of lead-in receiving apertures therein, the receiving apertures having a diameter greater than the given diameter and each having an oppositely extending, radial slot extending therefrom, each of the slots having a width less than the given diameter. The mica heat shield is positioned on the lead-ins closely and adjacent to the upper surface of the flare by having the slots in frictional engagement with the lead-ins.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: May 26, 1998
    Assignee: Osram Sylvania Inc.
    Inventor: Glen P. Williamson
  • Patent number: 5754005
    Abstract: An inlead for an electric lamp formed of an alloy of tungsten and molybdenum. The inlead has a rate of thermal expansion or contraction approximating that of the glass forming the bulb. This minimizes the expansion/contraction mis-match stress between the two materials. In addition, the alloy composition functions to reduce oxidation and degradation of the lead.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: May 19, 1998
    Assignee: General Electric Company
    Inventors: George E. Sakoske, Wayne A. Lasch, Joseph M. Ranish, Milan R. Vukcevich, Thomas H. Yu, Bernard W. Rachel, Richard G. Lynce, Istvan Meszaros, Gyorgy Nagy, Tamas Gal
  • Patent number: 5742123
    Abstract: A sealing structure for a light-emitting bulb assembly includes a closure, having a core which serves as an electrode for sealing an open end of a bulb. The closure includes a bulb-side region disposed adjacent to the open end of the bulb and made of a compositional ingredient having a coefficient of thermal expansion which is substantially the same as that of the bulb, a core-side region disposed adjacent to the core and made of a compositional ingredient having a coefficient of thermal expansion which is substantially the same as that of the core, and an intermediate region disposed between the bulb-side region and the core-side region and made of a compositional ingredient having compositional proportions adjusted such that a coefficient of thermal expansion thereof varies gradually from the coefficient of thermal expansion of the bulb-side region toward the coefficient of thermal expansion of the core-side region.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: April 21, 1998
    Assignee: Toto Ltd.
    Inventor: Hiroyuki Nagayama
  • Patent number: 5729091
    Abstract: A metal halide discharge lamp with a coaxial discharge vessel (2) and outer ulb (9) contains a fill of metals with a tendency to diffusion. Their specific content is less than 6 .mu.mols/cm.sup.3. The current supply leads (4, 5) are surrounded, over a large portion of their length, by a sheath (14) that is UV-shielded.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: March 17, 1998
    Assignee: Patent-Treuhand-Gesellschaft F. Electrische Gluehlampen mbH
    Inventors: Clemens Barthelmes, Andreas Hohlfeld, Jurgen Vom Scheidt, Dietrich Fromm
  • Patent number: 5705887
    Abstract: A fluorescent lamp is disclosed containing a deposit of a dried metal hydride-containing paste. The dried metal hydride-containing paste has a decomposition temperature higher than the temperature present during normal lamp operation. At the end of the lamp life, an increase in lamp temperature decomposes the metal hydride-containing paste and releases hydrogen within the lamp. The presence of hydrogen causes the lamp to extinguish passively without significant end heating or glass cracking.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: January 6, 1998
    Assignee: Osram Sylvania Inc.
    Inventor: John W. Shaffer
  • Patent number: 5598063
    Abstract: This lamp comprises an envelope of vitreous light-transmitting material enclosing an internal space, light-generating means within said space, and conductive lead structure projecting into said space and comprising inner and outer lead members and a foil member connected between said lead members. A first portion of the envelope surrounds the foil member and is sealed thereto, and a second portion of the envelope is located inwardly of the first portion. A tubular bead of vitreous material is provided about the inner lead member. This bead fits within the second envelope portion, is joined thereto, and supports the inner lead member in a precise predetermined portion within the envelope. The inner lead member projects inwardly beyond the bead and provides support for the light-generating means.
    Type: Grant
    Filed: December 16, 1992
    Date of Patent: January 28, 1997
    Assignee: General Electric Company
    Inventors: Paul G. Mathews, Martin N. Hassink
  • Patent number: 5585693
    Abstract: A fluorescent lamp comprises a glass tube, an electrode at each end of the tube, each of the electrodes including a pair of lead wires extending through each sealed end of the tube and joined to a coil, and a capsule containing metal hydride disposed in the tube and having a decomposition temperature higher than temperatures within the tube during normal operation of the lamp.
    Type: Grant
    Filed: July 18, 1995
    Date of Patent: December 17, 1996
    Assignee: Osram Sylvania Inc.
    Inventor: John W. Shaffer
  • Patent number: 5498927
    Abstract: In the low-pressure sodium discharge lamp the current conductors (3) have a first (4) and a second glass coating (6). The first coating (5) of borate glass extends from inside the discharge vessel (1) through a pinch seal (4). The second coating (6) of lime glass envelopes the first one (5) within the pinch seal (4) and extends to outside the discharge vessel (4). The occurrence of cracks in the pinch seal is thereby obviated.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: March 12, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Karel R. Vervecken, Petrus M. G. Van Gennip
  • Patent number: 5387840
    Abstract: The electric lamp has a glass lamp vessel in the wall of which current conductors of molybdenum or tungsten are accommodated, which extend to the outside. Exclusively where the current conductors are in contact with gas, they have a skin of their own phosphide. The skin protects the current conductors from being progressively oxidized. The lamps can easily be manufactured.
    Type: Grant
    Filed: January 8, 1993
    Date of Patent: February 7, 1995
    Assignee: U.S. Philips Corporation
    Inventors: Victor R. Noteleteirs, Leo F. M. Ooms
  • Patent number: 5374872
    Abstract: This lamp comprises (1) an envelope of vitreous light-transmitting material enclosing an internal space where light is generated and (ii) conductive lead structure projecting into said internal space. Surrounding and sealed to said lead structure is a body of vitreous material formed of particles of vitreous material pressed together and sintered. This body extends through an opening in the envelope that communicates with said internal space. A hermetic seal is provided between said envelope and said body in the interface region between said envelope and said body.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: December 20, 1994
    Assignee: General Electric Company
    Inventors: Edward J. Balaschak, Curtis E. Scott, George E. Sakoske
  • Patent number: 5250872
    Abstract: In a discharge lamp unit in which a discharge lamp (10), which is formed by pinch-sealing (13a, 13b) a glass tube in such a manner as to define a closed glass ball (12) forming an electric discharge region substantially at the middle of the ball and in which discharge electrodes (15a, 15b) are arranged confronted with each other, is supported at both ends by metal supports (30, 40) which are welded to a short lead support (22) and a long lead support (24) protruding from an insulating base (20) in such a manner that the lead supports (22, 24) are parallel to one another with a predetermined distance therebetween and are parallel to the discharge axis of the lamp. The metal support (30) which supports the rear end portion of the discharge lamp has a discharge lamp holding portion (34) which is arcuate, and the part (14) of the rear end portion of the discharge lamp which is held by the discharge lamp holding portion of the metal support is circular in cross section.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: October 5, 1993
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Yukio Wakimizu, Hirohiko Ohshio, Yonemasa Yoshida, Yasuo Hirozumi, Masami Handa
  • Patent number: 5248913
    Abstract: To prevent ion migration from a discharge vessel (4) into an evacuated sp between the discharge vessel and an outer bulb (1), a shield wire (13) is interposed between the current supply lead (12) extending longitudinally within the outer bulb and the discharge vessel (4), and both the shield wire (13) and the current supply (12) are insulated by a high dielectric insulating material. A suitable material is a ceramic, like Al.sub.2 O.sub.3 or Ba.sub.2 TiO.sub.4, for example, as a single ceramic body with ducts for, respectively, the current supply lead (12) and the shielding wire (13), or, alternatively, to form separate ceramic sleeves (17, 18).
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: September 28, 1993
    Assignee: Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen m.b.H.
    Inventor: Jurgen Heider
  • Patent number: 5216690
    Abstract: A grounded metallic shield which comprises an electrode enclosing the filament leads and emitters of an e-Gun in a high vacuum chamber of the type used in melting and casting metals and other materials and evaporation sources. The shield is spaced from the filament leads and emitters a distance in the order of the electron mean free path for the pressure uses within the high vacuum chamber. The structure and method of use thereof suppresses or eliminates arc-downs or glow discharges.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: June 1, 1993
    Inventor: Charles W. Hanks
  • Patent number: 5140222
    Abstract: To reduce the quantity of a noble gas, typically xenon, and improve the sk and vibration resistance of the quartz glass bulb upon possible movement of electrode support shafts (4, 4') in transport or handling, a support element (6, 6') is engaged against a constriction between the bulb portion (1) and the neck portions (2, 2') of the discharge vessel structure. A spiral spring (8), preferably of tungsten, is engaged against one or more ceramic, perferably aluminum oxide disks, backed up against a melt seal, and pressing the respective disk or disks against the support element. The ceramic disks are loosely seated on the electrode shaft and located within the neck portions with clearance, so that, upon operation of the lamp, and expansion due to heating of the ceramic disks, the stability of the arc is improved and ignition is facilitated due to the lower fill pressure of the noble gas.
    Type: Grant
    Filed: July 18, 1991
    Date of Patent: August 18, 1992
    Assignee: Patent Treuhand Gesellschaft fur Elektrische Gluhlampen m.b.H
    Inventor: Alfred Roznerski
  • Patent number: 5107177
    Abstract: With high-pressure discharge lamps, and, more specifically, ultra high-prure discharge lamps, the electrode shafts (4, 5) are located within cylindrical elongated necks (2, 3) of quartz glass extending from the arc tube (1). To prevent adhesion of quartz from the cylindrical elongated necks (2, 3) of the arc tube (1) upon melt-sealing the necks (2, 3) to the electrode shafts (4, 5), the electrode shafts (4, 5) are surrounded by flexible tissue or fabric hoses, tubes or braids (21, 22), made of highly heat-resistant, electrically insulating inorganic material, for example made of quartz fibers. The tissue hose has an inner diameter which corresponds at least to the outer diameter of the eletrode shaft (4, 5) and is not more than 0.5 mm greater than the electrode shaft.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: April 21, 1992
    Assignee: Patent Treuhand Gesellschaft fur elektrische Gluhlampen mbH
    Inventors: Clemens Barthelmes, Andreas Hohlfeld
  • Patent number: 5064395
    Abstract: A compact arc discharge lamp may be formed with an inner lamp capsule and an outer envelope. One or more of the leads to the inner capsule may be sheathed to insulate the lead from improper arc over. The sheath may passed through the seal of the outer envelope, so the gas state of the intermediate volume may be adjust before final sealing.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: November 12, 1991
    Assignee: GTE Products Corporation
    Inventors: Michael R. Kling, Thomas J. Gilligan, III
  • Patent number: 4866328
    Abstract: An HID lamp having parts of its internal metal support covered with a layer of material having a photoelectric work function greater than 5.0 electron volts to reduce internal photoelectron production. The material may be granular zirconium oxide having a photoelectric work function of 5.8 eV.
    Type: Grant
    Filed: April 15, 1988
    Date of Patent: September 12, 1989
    Assignee: North American Philips Corp.
    Inventors: Raghu Ramaiah, Daniel H. Shumway
  • Patent number: 4780646
    Abstract: To provide an electrode connection lead (8) made of tungsten positioned on he inside of a high-pressure discharge lamp (1,2) which contains a fill attacking niobium, while providing for a melt connection including niobium to the discharge vessel, to permit use of aluminum oxide ceramic for the discharge vessel--since niobium and aluminum oxide ceramic have approximately the same thermal coefficient of expansion--the tubular discharge vessel is formed with an end portion defining an abutment (5), against which an internal aluminum oxide ceramic disk (4) is seated, defining a recess (4a) within which a niobium sealing disk (6) is partly located. An identical external sealing disk (3) receives the remainder of the niobium sealing disk. An external current supply lead (7) of niobium is welded to the niobium sealing disk. The internal current supply lead (8) of tungsten, likewise, is welded to the niobium sealing disk.
    Type: Grant
    Filed: October 14, 1987
    Date of Patent: October 25, 1988
    Assignee: Patent Treuhand Gesellschaft fur elektrische Gluhlampen mbH
    Inventor: Horst Lange
  • Patent number: 4754195
    Abstract: To improve the high-voltage flash-over characteristics of high-pressure dharge lamps (1), and especially to prevent flash-over between terminal leads emanating from the lamp bulb and extending into a lamp base (14), the lamp base which is formed with a cup-shaped opening (13) has an insert pad (18) placed therein of fibrous web, pile, fleece or mat material, made of ceramic, quartz or glass fibers. In manufacture, the fibers are compressed, thereby fitting tightly against the terminal end, typically a pinch or press seal, of the discharge lamp bulb, and thereby substantially increasing the high voltage flash-over resistance between the terminal leads and permitting hot re-ignition of the lamp, which may require pulses of between 15 to 20 kV.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: June 28, 1988
    Assignee: Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH
    Inventors: Erhard Rasch, Jurgen Heider, Werner Eisele
  • Patent number: 4539511
    Abstract: In a high pressure sodium discharge lamp it has been found that rectification can be prevented by ensuring the amalgam does not make electrical contact with the electrode. To achieve this according to the invention a small shoulder member is provided on the inside face of the end wall. Although the small height effectively reduces the temperature differential between the bottom of the shoulder and the top the necessary differential to prevent the amalgam condensing out the top of the shoulder member is maintained by ensuring the width of the shoulder member is a predetermined minimum thickness.
    Type: Grant
    Filed: September 3, 1982
    Date of Patent: September 3, 1985
    Assignee: Thorn EMI plc
    Inventors: Paul L. Denbigh, Richard J. Seddon, Bryan F. Jones
  • Patent number: 4479071
    Abstract: The invention relates to a high-pressure metal halide lamp in which the filling of the discharge vessel also comprises an alkali metal. The discharge vessel is surrounded by an outer envelope. One electrode of the discharge vessel is connected to a current supply conductor extending between the discharge vessel and the outer envelope. A plate-shaped element is mounted between the discharge vessel and the outer envelope in such manner that, viewed from the discharge vessel, the current supply conductor is present substantially entirely behind the plate-shaped element.According to the invention, the plate-shaped element comprises boron nitride.Increase of the arc voltage of the lamp and increase of the color temperature of the radiation emitted by the lamp is prevented in this manner.
    Type: Grant
    Filed: March 8, 1982
    Date of Patent: October 23, 1984
    Assignee: U.S. Philips Corporation
    Inventors: Germain R. T'Jampens, Abraham Coomans
  • Patent number: 4437038
    Abstract: A hollow cathode type light source is provided having improved operating stability by forming the cathode of an alloy of a highly reactive, unstable prime metal of interest for spectral emission, and of a chemically stable, readily sputtered metal. An alloy of silver and calcium with a small amount of magnesium provides a hollow cathode device which exhibits stable operation after a minimum warm-up time.
    Type: Grant
    Filed: May 29, 1979
    Date of Patent: March 13, 1984
    Assignee: Westinghouse Electric Corp.
    Inventors: Vincent F. Link, George K. Yamasaki
  • Patent number: RE35024
    Abstract: A grounded metallic shield which comprises an electrode enclosing the filament leads and emitters of an e-Gun in a high vacuum chamber of the type used in melting and casting metals and other materials and evaporation sources. The shield is spaced from the filament leads and emitters a distance in the order of the electron mean free path for the pressure uses within the high vacuum chamber. The structure and method of use thereof suppresses or eliminates arc-downs or glow discharges.
    Type: Grant
    Filed: March 24, 1994
    Date of Patent: August 22, 1995
    Inventor: Charles W. Hanks