Temperature Modification Patents (Class 378/127)
  • Patent number: 6705759
    Abstract: An X-ray system (10) includes an X-ray tube (16) that has a temperature sensor (22) coupled thereto. The temperature sensor (22) may be included in a heat exchanger (18). The temperature sensor (22) generates a temperature signal that is provided to a controller (12). The controller (12) generates a fan speed control signal that is used to control the speed of the fan (20) in response to the temperature signal.
    Type: Grant
    Filed: September 19, 2002
    Date of Patent: March 16, 2004
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventors: Charles B. Kendall, Thomas Schaefer
  • Patent number: 6693990
    Abstract: A bearing assembly for a rotating anode x-ray device. The bearing assembly includes a shaft having a flange at one end for attachment of the anode thereto. The shaft defines front and rear inner races and includes a plurality of extended surfaces. Front and rear outer race elements define front and rear outer races, respectively, corresponding to the front and rear inner races, respectively, defined by the shaft. The front and rear outer race elements cooperate with the shaft to confine front and rear ball sets which facilitate rotary motion of the shaft. A spacer including extended surfaces assists in the positioning of the front and rear outer race elements in a bearing housing. The extended surfaces of the shaft and spacer, in conjunction with emissive coatings provided on various portions of selected components of the bearing assembly, facilitate a relative improvement in heat transfer out of the bearing assembly.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: February 17, 2004
    Assignee: Varian Medical Systems Technologies, Inc.
    Inventor: Gregory C. Andrews
  • Patent number: 6603834
    Abstract: An x-ray tube assembly (16) includes a housing (40) and an insert frame (54) supported within the housing (40), such that the insert frame (54) defines a substantially evacuated envelope in which a cathode assembly (60) and a rotating anode assembly (58) operate to produce x-rays. The rotating anode assembly (58) includes an anode target plate (64) coupled to a rotor (66) and bearing shaft (82), which is rotatably supported within a bearing housing (84), by a plurality of ball bearings (86). A heat barrier (90) substantially surrounds the bearing housing (84) and is coupled, along with the bearing housing (84) to an anode cold plate (100). The anode cold plate (100) includes a grooved cover (102), a basin (110), and a plurality of corrugated fins (120) disposed therein. Coupling both the bearing housing (84) and the heat barrier (90) to the anode cold plate (100) provides an effective means for cooling the bearing assembly (80).
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: August 5, 2003
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventors: Qing K. Lu, Todd R. Bittner, Allan D. Kautz, Gerald J. Carlson, Thomas R. Miller, Jose A. Buan, Salvatore G. Perno, Paul M. Xu, Patrick P. McNally
  • Patent number: 6584172
    Abstract: A brazed X-ray target includes a metallic cap and a graphite back including a nonlinear record groove attached thereto along a stepped surface. An upper corner joint of the stepped surface is distanced from a cap outer edge and a focal track where the maximum heat is generated during use of the target. The graphite back is extended outward toward the cap outer edge to increase a thermal storage of the graphite, and a recess is formed into the cap to maintain a selected moment of inertia of the target and thereby maintain the rotordynamics of a given X-ray tube.
    Type: Grant
    Filed: August 26, 2002
    Date of Patent: June 24, 2003
    Assignee: General Electric Company
    Inventors: Thomas C. Tiearney, Thomas Robert Raber, Pazhayannur Ramanathan Subramanian, Srihari Balasubramanian
  • Patent number: 6529579
    Abstract: A cooling system for use with high-powered x-ray tubes. The cooling system includes a reservoir containing liquid coolant, in which the high-powered x-ray tube is partially immersed. In general, the liquid coolant is cooled and then circulated through the reservoir by an external cooling unit. The cooling system also includes a shield structure attached to the vacuum enclosure of the high-powered x-ray tube and disposed substantially about the aperture portion of the vacuum enclosure, thereby defining a flow passage proximate to the aperture portion. Liquid coolant supplied by the external cooling unit enters the flow passage by way of an inlet port in the shield structure. After passing through the flow passage and transferring heat out of the aperture portion, the liquid coolant is discharged through an outlet port in the shield structure and enters the reservoir to repeat the cycle.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: March 4, 2003
    Assignee: Varian Medical Systems, Inc.
    Inventor: John Richardson
  • Patent number: 6512816
    Abstract: An x-ray system 20 includes an x-ray tube insert (24) that has an evacuated envelope (34), an anode assembly (38) and a cathode assembly (40). The anode assembly (38) and the cathode assembly (40) are located in operative relationship to one another within the evacuated envelope (34). A temperature indicating member (100) is located in thermally conductive contact with at least one assembly (38, 40, 66) located in the x-ray tube insert (24). The temperature indicating member (100) has a temperature sensitive characteristic which changes in response to adequate thermal exposure to at least one temperature threshold value.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: January 28, 2003
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventors: Cheryl L. Panasik, Daniel E. Kuzniar
  • Patent number: 6477231
    Abstract: An x-ray generating device or system include an anode assembly including a target; a cathode assembly disposed at a distance from the anode assembly, the cathode assembly configured to emit electrons that strike the target of the anode assembly, producing x-rays and residual energy; a heat receptor, positioned between the anode assembly and a bearing assembly supporting the anode assembly, for absorbing an amount of the residual energy; and a heat exchanger, in thermal communication with the heat receptor, for carrying a cooling medium and conducting an amount of the residual energy absorbed by the heat receptor away from the heat receptor.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: November 5, 2002
    Assignee: General Electric Company
    Inventors: Douglas J. Snyder, Craig Higgins, John Warren, Mark Vermilyea, Thomas Ebben
  • Patent number: 6477236
    Abstract: A rotary anode X-ray tube, comprising a rotor, a stationary structure, a dynamic pressure slide bearing formed between the rotor and the stationary structure, the stationary structure having a lubricant storage chamber and provided with a lubricant passageway, and a vacuum vessel. Holes are formed in the stationary structure extending from the lower edge surface along the tube axis and not to cross the lubricant storage chamber and the lubricant passageway. Heat transfer members for the stationary structure having a heat conductivity higher than that of the stationary structure are inserted into the holes, respectively. A heat transfer member having a heat conductivity higher than that of the inner cylindrical structure of the rotor is bonded in a cylindrical form to the outer circumferential wall of the inner cylindrical structure constituting a bearing. A heat transfer member can be mounted to each of the rotor and the stationary structure.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: November 5, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidero Anno, Yukinari Yoshida, Hironori Nakamuta
  • Patent number: 6463125
    Abstract: A brazed X-ray target includes a metallic cap and a graphite back including a nonlinear record groove attached thereto along a stepped surface. An upper corner joint of the stepped surface is distanced from a cap outer edge and a focal track where the maximum heat is generated during use of the target. The graphite back is extended outward toward the cap outer edge to increase a thermal storage of the graphite, and a recess is formed into the cap to maintain a selected moment of inertia of the target and thereby maintain the rotordynamics of a given X-ray tube.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: October 8, 2002
    Assignee: General Electric Company
    Inventors: Constantinos Minas, Mark G. Benz, Charles G. Mukira, Paul A. Siemers, Thomas Robert Raber, John Robert Breunissen, Richard Warren Lindberg, Gregory A. Steinlage, Douglas J. Snyder, Ping Huang, James Michael Gent, Gregory Reznikov
  • Patent number: 6459768
    Abstract: A method and apparatus for providing a window frame and window for use in an x-ray tube, wherein the new structure reduces deforming stresses on the window produced by pressure differential incident upon the window. The support structure of the window frame to which the window is attached is angled toward the interior of the x-ray tube to an angle equaling the deflection to which a window is typically subjected in standard window frames. A window mounted to a frame in accordance with the present invention is subjected to reduced or eliminated deforming stresses, even in high deflection stress environments including air bake x-ray tube manufacturing processes. This elimination of deforming stresses allows for the use of thinner x-ray tube windows enabling a higher transmissivity of produced x-rays.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: October 1, 2002
    Assignee: Varian Medical Systems, Inc.
    Inventors: Thomas Koller, Charles Lynn Chidester, Mark Alan Heber
  • Patent number: 6456690
    Abstract: An X-ray generator, an X-ray inspector and an X-ray generation method capable of automatically focusing an energy beam, such as an electron beam for generating an X-ray, on a target are provided. The generation, inspector and the method have been developed by turning an attention on the fact that convergence conditions of an electron beam has a close relationship with a temperature on a surface of an X-ray tube target. The method comprises the steps of measuring the temperature changes at real time by a temperature sensor 14 and automatically controlling a current value of a focusing coil 6.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: September 24, 2002
    Assignee: mediXtec Japan Corporation
    Inventors: Koichi Yamada, Takeshige Tanigaki
  • Patent number: 6453010
    Abstract: An x-ray tube apparatus includes a housing defining a chamber and an x-ray tube mounted therein. The x-ray tube includes an envelope defining an evacuated void in which an anode assembly is rotatably mounted to a bearing assembly. The anode assembly interacts with a cathode assembly for the production of x-rays. The bearing assembly includes a cooling channel that is defined within the bearing assembly to direct cooling fluid, such as oil, across an inner surface of the bearing housing. A flow director is located in a fluid input port in the housing and has a fluid input aperture for connecting the flow director to the heat removal system. A cavity is defined by the housing of the flow director and two fluid output apertures are in fluid communication with each other and the fluid input opening. One of the fluid output apertures supplies cooling fluid to the cooling channel in the bearing assembly and the other fluid output aperture supplies cooling fluid to the chamber in the housing.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: September 17, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Thomas R. Miller, Cheryl L. Panasik, Qing Lu
  • Patent number: 6445770
    Abstract: A high energy x-ray tube includes an evacuated chamber (12) containing a rotor (34) which rotates an anode (10) in the path of a stream of electrons (A) to generate an x-rays (B) and heat. The rotor includes a bearing shaft (54, 80, 122) connected to the anode by a thermally conductive structure (40). The bearing shaft carries soft metal-lubricated bearing balls (44F, 44R) in forward and rear bearing races (64, 66, 106, 108, 128, 130). An annular groove (70, 94, 132) is defined longitudinally in the shaft which, particularly when evacuated, provides a thermal barrier between the forward race and the portion of the shaft that is thermally connected with the anode. The groove lengthens the path heat entering the bearing shaft travels in order to reach the forward bearing race. As a result, the temperature of the forward race, and hence the evaporation of lubricant during operation of the x-ray tube, is reduced.
    Type: Grant
    Filed: February 10, 2000
    Date of Patent: September 3, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Norman E. Wandke, Mark S. Maska, Donald C. Mueller
  • Patent number: 6430263
    Abstract: A CT scanner comprises an x-ray window mounted on an x-ray tube, a cooling fluid circulation line, and a cooling fluid return line. A cold-plate is operatively mounted on the x-ray tube around the x-ray window. The cold plate includes an elongated shell and corrugated fins for rapidly removing heat from the x-ray window. The circulation line is in fluid communication with an inlet of the cold-plate, a cooling fluid reservoir defined between the x-ray tube and a surrounding housing, and a heat exchanger. The return line is in fluid communication with an outlet of the cold-plate, the cooling fluid reservoir, and the heat exchanger. A pump circulates the cooling fluid through the heat exchanger, the suction and return lines, the cold-plate, and the x-ray tube housing.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: August 6, 2002
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventors: Qing Kelvin Lu, Andrew R. Kaczmarek, Paul M. Xu
  • Patent number: 6426998
    Abstract: An x-ray radiator has a housing containing a fluid coolant wherein a rotating bulb x-ray tube is rotatably seated, the rotating bulb x-ray tube having an evacuated vacuum housing containing a cathode and an anode, with the anode forming a wall of the vacuum housing and having an exterior charged by the coolant. The anode has a profiling at its exterior that enlarges the surface area contact between the exterior of the anode and the coolant. The profiling can be in the form of at least one channel proceeding from as a spiral from a central region of the anode toward its periphery.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: July 30, 2002
    Assignee: Siemens Aktiengesellschaft
    Inventors: Erich Hell, Detleff Mattern, Thomas Ohrndorf, Peter Schardt
  • Publication number: 20020085676
    Abstract: An anode target for use within an x-ray generating device including a target frame having an inner surface and an outer surface and a thermal energy transfer device. The thermal energy transfer device including a heat exchanger having an inner surface and an outer surface, at least a portion of the outer surface of the heat exchanger positioned adjacent to at least a portion of the inner surface of the target frame; a cooling medium circulating through the heat exchanger for convectively cooling the anode target; and a thermal coupling medium disposed between the inner surface of the target frame and the outer surface of the heat exchanger, the thermal coupling medium thermally coupling the target frame with the heat exchanger while permitting relative motion between the target frame and the heat exchanger.
    Type: Application
    Filed: December 29, 2000
    Publication date: July 4, 2002
    Inventor: Douglas J. Snyder
  • Patent number: 6390875
    Abstract: A method is provided for enhancing heat transfer within an X-ray vacuum tube, from a hot component such as the rotating anode assembly to a cooler component such as the metal tube housing, by increasing surface emissivity of respective components. The method comprises the steps of fabricating each component from an alloy containing a specified minimum amount of chromium, and then implementing a first heating operation, wherein a fabricated component is heated in a dry hydrogen atmosphere for a first specified time period. Thereafter, a second heating operation is implemented, wherein the fabricated component is heated in a wet hydrogen atmosphere for a second specified time period. This procedure forms a refractory chromium oxide coating on the component that exhibits high absorption in the NIR region of the electromagnetic spectrum.
    Type: Grant
    Filed: March 24, 2000
    Date of Patent: May 21, 2002
    Assignee: General Electric Company
    Inventors: John M. Warren, Michael Price, Martin W. Plutowski
  • Patent number: 6377659
    Abstract: A thermal energy transfer device for use with an x-ray generating device or x-ray system including an anode assembly having a target, a cathode assembly positioned at a distance from the anode assembly configured to emit electrons that strike the target producing x-rays and residual energy in the form of heat, and a rotatable shaft supported by a bearing assembly. The thermal energy transfer device including a thermal gradient device positioned adjacent to and in thermal communication with one end of the shaft, the thermal gradient device operable for transferring heat away from that end of the shaft, and a fin structure positioned adjacent to and in thermal communication with the thermal gradient device, the fin structure operable for convectively cooling the thermal gradient device.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: April 23, 2002
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventors: Douglas J. Snyder, Eric Chabin
  • Patent number: 6364527
    Abstract: A rotating bulb x-ray radiator has an x-ray tube accepted in a housing filled with a coolant, the x-ray tube being torsionally connected to the housing and being mounted so as to be rotatable together therewith. The housing is at least partially formed of a material that is highly attenuating for x-rays.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: April 2, 2002
    Assignee: Siemens Aktiengesellschaft
    Inventor: Wolfgang Kutschera
  • Publication number: 20010050972
    Abstract: An X-ray generator, an X-ray inspector and an X-ray generation method capable of automatically focusing an energy beam, such as an electron beam for generating an X-ray, on a target are provided. The generation, inspector and the method have been developed by turning an attention on the fact that convergence conditions of an electron beam has a close relationship with a temperature on a surface of an X-ray tube target. The method comprises the steps of measuring the temperature changes at real time by a temperature sensor 14 and automatically controlling a current value of a focusing coil 6.
    Type: Application
    Filed: December 20, 2000
    Publication date: December 13, 2001
    Applicant: mediXtec Japan Corporation
    Inventors: Koichi Yamada, Takeshige Tanigaki
  • Patent number: 6307916
    Abstract: An x-ray tube for emitting x-rays which includes an anode assembly and a cathode assembly is disclosed herein. The x-ray tube includes a vacuum vessel, an anode assembly disposed in the vacuum vessel and including a target, a cathode assembly disposed in the vacuum vessel at a distance from the anode assembly, and a heat pipe is supported relative to the anode assembly. The cathode assembly is configured to emit electrons which hit the target of the anode assembly and produce x-rays. The heat pipe transfers thermal energy away from the target through the vacuum vessel. The heat pipe provides for greater thermal transfer down the bearing shaft of the anode assembly, thereby providing greater cooling of the anode assembly.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: October 23, 2001
    Assignee: General Electric Company
    Inventors: Carey S. Rogers, Douglas J. Snyder, Michael J. Price
  • Patent number: 6295338
    Abstract: An x-ray tube (20) comprising a cathode (23) and an anode (24) in operative relationship with the cathode (23). The anode (24) is mounted on a stem (32). The x-ray tube includes at least one bearing (58) rotatably receiving the stem (32). The at least one bearing (58) has an outer bearing race (66) in an outer race member, an inner bearing race (62) and a plurality of bearing members (64) operatively disposed between the inner and outer bearing races. The x-ray tube (20) also includes an evacuated envelope (78) which encloses the tube components and receives the outer race member of the at least one bearing (58) in thermally conductive contact along an inner surface (79).
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: September 25, 2001
    Assignee: Marconi Medical Systems, Inc.
    Inventors: Daniel E. Kuzniar, Jason P. Harris, Gerald J. Carlson
  • Patent number: 6160868
    Abstract: Heat removal apparatus is provided for an X-ray tube having a frame, a shaft mounted for rotation with respect to the frame, and an anode supported on the shaft for rotation therewith. The apparatus comprises a heat transfer component, which is fixably joined to the frame in closely spaced relationship with an end portion of the rotatable shaft, and further comprises a radially, axially and tilt compliant sealing device, such as a flexible bellows, which is positioned to substantially enclose a space extending between the heat transfer component and a specified end portion of the shaft. A selected thermally conductive liquid metal, such as a gallium alloy, is contained within the enclosed space to provide a path for the flow of heat from the shaft to the heat transfer component, as the shaft and the anode rotate with respect to the frame. Such arrangement also permits expansion of the liquid metal, in the event of freezing.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: December 12, 2000
    Assignee: General Electric Company
    Inventors: Douglas J. Snyder, Carey S. Rogers
  • Patent number: 6125169
    Abstract: An x-ray tube includes an envelope defining an evacuated chamber in which an anode assembly is rotatably mounted to a bearing assembly and interacts with a cathode assembly for production of x-rays. The x-ray tube further includes a heat shield disposed in the envelope. The heat shield serves to reduce heat radiating from the anode assembly which is transferred to the bearing assembly or otherwise serves to insulate the bearing assembly from such radiated heat. The heat shield is brazed or otherwise bonded to the anode assembly and is comprised of a material having a low emissivity so that a minimum amount of heat radiates through the heat shield.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: September 26, 2000
    Assignee: Picker International, Inc.
    Inventors: Norman E. Wandke, Gerald J. Carlson, Lester D. Miller, Qing Lu
  • Patent number: 6075838
    Abstract: A plasma x-ray source includes a chamber defining a pinch region having a central axis, a gas supply for introducing a gas mixture into the pinch region, a preionizing device disposed around the pinch region for preionizing the gas mixture in the pinch region, and a pinch anode and a pinch cathode disposed at opposite ends of the pinch region. The gas mixture includes a primary X-radiating gas, such as xenon, and a low atomic number diluent gas, such as helium. The pinch anode and the pinch cathode produce a current through the plasma shell in an axial direction and produce an azimuthal magnetic field in the pinch region in response to application of a high energy electrical pulse to the pinch anode and the pinch cathode. The azimuthal magnetic field causes the plasma shell to collapse to the central axis and to generate X-rays. The gas mixture provides enhanced radiation intensity and reduced cost for the primary X-radiating gas.
    Type: Grant
    Filed: March 18, 1998
    Date of Patent: June 13, 2000
    Assignee: PLEX LLC
    Inventor: Malcolm W. McGeoch
  • Patent number: 5982849
    Abstract: A high temperature warning device for an x-ray source has a housing that can be attached to the exterior of the housing wall of an x-ray generator housing. The device has an integrated signaling alarm which is activated depending on the detection result of at least one temperature sensor communicating with the x-ray generator housing.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: November 9, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventor: Norbert Bischof
  • Patent number: 5978447
    Abstract: A rotating assembly 79 includes an anode assembly 55 coupled to a shaft 70 and a rotor 75 including a rotor body 77. The anode assembly 55 includes an elongated neck portion 58 and is rotated via the shaft 70 about an axis of rotation 65 in an x-ray tube 12. The shaft 70 is mounted by a straddle bearing assembly 68 having a bearing housing 100. The bearing housing 100 includes a first elongated portion 101 and second elongated portion 102, and a base portion 103. The first elongated portion 101 and the second elongated portion 102 each pass through a center of mass C of the rotating assembly 79 and define an cooling duct 119 for removing heat from the anode assembly 55 during operations. A first bearing 90a and a second bearing 90b are disposed in the bearing housing 100 on opposite sides of the center of mass C of the rotating assembly 79.
    Type: Grant
    Filed: November 11, 1997
    Date of Patent: November 2, 1999
    Assignee: Picker International, Inc.
    Inventors: Gerald J. Carlson, Jason P. Harris
  • Patent number: 5867556
    Abstract: In an X-ray tube having a housing, an outer frame for providing a vacuum, a cathode mounted in the outer frame to project a stream of electrons, and an anode disposed to receive the electron stream at a focal spot position to produce X-rays, apparatus is provided for selectively mounting the anode within the housing. More particularly, the apparatus is disposed to respond to the heat generated by the X-ray production process to provide compensation for undesirable effects resulting from thermal expansion of the anode.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: February 2, 1999
    Assignee: General Electric Company
    Inventors: Douglas J. Snyder, Thomas Block, Dale G. Chrisien
  • Patent number: 5629970
    Abstract: An x-ray tube target includes an annular disk having an outer surface including front and back opposite faces, and an annular focal track fixedly joined to the disk front face for producing x-rays. The disk outer surface is rough away from the focal track, with surface roughness pits having width and depth dimensions greater than a wavelength of peak radiant emission of the target at operating temperature for increasing emissivity of the target to increase thermal radiation cooling thereof.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: May 13, 1997
    Assignee: General Electric Company
    Inventors: David W. Woodruff, Robert D. Lillquist
  • Patent number: 5579364
    Abstract: A rotating-anode X-ray tube has a rotary pipe rotatably supported in a casing, and a target which is fixed to one end of the rotary pipe and can rotate along with the rotary pipe, the target being cooled by a flow of cooling fluid. A cooling-fluid sealing device is provided between the casing and the rotary pipe and is a mechanical seal. The mechanical seal has a rotary ring which is rotatable along with the rotary pipe and axially movable, a stationary ring fixed to the casing, and pressing means for pressing the rotary ring against the stationary ring. The rotary and the stationary rings come into surface contact with each other within a plane perpendicular to an axis of rotation. The rotary ring is made of carbon and the stationary ring is made of silicon carbide ceramics, both materials being electrically conductive.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: November 26, 1996
    Assignee: Rigaku Corporation
    Inventors: Naohisa Osaka, Toru Kobayashi
  • Patent number: 5414748
    Abstract: An x-ray tube having a rotating anode structure which comprises a circular titantium, zirconium, molybdenum alloy target section bonded to a graphite disc. The target section is coated with hefnium carbide as a heat emissivity barrier. The thickness of the barrier is preferably in the range of 4.0-5.0 .mu.m.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: May 9, 1995
    Assignee: General Electric Company
    Inventor: Kamleshwar Upadhya
  • Patent number: 5345492
    Abstract: An x-ray tube (10) includes an anode (16), a cylindrical stem (22), and a rotor (24). The rotor (24) includes a cylindrical sleeve portion (32) and a head portion (34) which are joined together at a joint (36). The joint (36) is formed by a mating of a lip (46) in the sleeve portion (32) and a lip (48) in the head portion (34). The lip (48) of the head portion (34) fits about the lip (46) of the sleeve portion (32). The sleeve portion (32) is formed of a first material and the head portion (34) is formed of a second material, the first material having a thermal expansion coefficient greater than that of the second material such that the head portion (34) expands less than the sleeve portion (32) upon heating and thereby maintains the integrity of the joint (36) inasmuch as the head portion (34) overlaps the sleeve portion ( 32) in the region of the joint (36). The stem (22) is attached to the anode (16) at a first end (50) and attached to the head portion (34) at a second end (52).
    Type: Grant
    Filed: January 4, 1993
    Date of Patent: September 6, 1994
    Assignee: Eureka X-Ray Tube Corp.
    Inventors: John D. Weaver, Sr., Thomas J. Muchowicz, Arkady Kantor, George L. Awad
  • Patent number: 5295175
    Abstract: A method and apparatus are disclosed for generating X-rays employing a vacuum tube containing a cathode and an anode. A heat conducting member is connected to the anode. Equal amounts of heat are transmitted from different locations alone the length of the heat conducting member to an extended cooling surface remote from the anode, and the extended cooling surface is cooled.
    Type: Grant
    Filed: October 26, 1992
    Date of Patent: March 15, 1994
    Inventor: Norman Pond
  • Patent number: 5264801
    Abstract: A target track (20) of an anode (14) of an x-ray tube becomes heated adjacent a focal spot (18) to temperatures on the order of 1100.degree.-1400.degree. C. To protect the anode, a body portion (34) is coated (46) with a thermal energy emissive oxide layer (48). In order to prevent carbon from the body portion from migrating out to the oxide layer and forming carbon monoxide gas, a carbide forming barrier layer (36) is formed (38,40) between the body and the oxide coating. The barrier layer is a dense, substantially pore-free coating of a metal that has a free energy of carbide formation of at least 100 KJ/mole at 1200.degree. C. Preferably, the barrier layer material is zirconium, although hafnium, titanium, vanadium, uranium, tantalum, niobium, chromium, and their alloys also provide acceptable barriers to carbon atom migration.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: November 23, 1993
    Assignee: Picker International, Inc.
    Inventors: Donald Frank DeCou, Jr., James G. Hull
  • Patent number: 5259015
    Abstract: A rotary anode for use in an X-ray tube has a graphite substrate plate, an intermediate layer made of a metal that does not react with graphite, and an X-ray generating layer provided on the intermediate layer for generating X-rays when electron impact is applied. The intermediate layer is a rhenium film having an equiaxed grain structure. A method for manufacturing such a rotary anode is proposed. The method has the step of forming, on a graphite substrate plate, an intermediate layer of rhenium by subjecting a metallic chloride to the thermal decomposition CVD process at a substrate temperature of 1200.degree. C. or more. The method further has the step of forming, on the intermediate layer, an X-ray generating layer of tungsten or tungsten-rhenium alloy by subjecting a metallic fluoride to the hydrogen reduction thermal CVD process.
    Type: Grant
    Filed: May 13, 1992
    Date of Patent: November 2, 1993
    Assignees: Sumitomo Electric Industries, Ltd., Tokyo Tungsten Co., Ltd.
    Inventors: Hisanori Ohara, Hiromu Kawai, Shigehiko Takaoka, Yasuhiro Katoh
  • Patent number: 5247563
    Abstract: A method of bonding a metallic target layer and a graphite disk to provide a composite rotating X-ray tube target wherein a high vapor pressure metal is placed between the target layer and the graphite disk and the vapor pressure of the joint is controlled. The vapor pressure is controlled by limiting the thickness of the joint and thereby causing the metallic character of the braze joint in this region to be altered. In a preferred manner, this is effected by interfitting projecting and recessed portions in the graphite disk and metallic target layer. The preferred high vapor pressure metal is titanium. A composite X-ray tube target is produced having a high remelt temperature and thus capable of being employed in X-ray tubes having more aggressive protocols.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: September 21, 1993
    Assignee: General Electric Company
    Inventors: Wayne F. Block, John A. Holma
  • Patent number: 5224142
    Abstract: A rotary-anode X-ray tube having a rotor, a stationary shaft, and a sliding bearing connecting the rotor and the stationary shaft, forming a gap filled with liquid metal lubricant. The rotor has a first rotary member supporting an anode target and a second rotary member at which a sliding bearing is installed and which is coaxial with the first rotary member. The first and the second rotary members are connected at that end of the heat conductive path which is remote from the anode target. A heat insulating gap is formed at all fitting portions, but the remote end. Therefore, the temperature rise of the sliding bearing is controlled without using refregerant, and stable rotation of the bearing is secured.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: June 29, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiro Ono, Hidero Anno, Hiroyuki Sugiura, Takayuki Kitami
  • Patent number: 5206895
    Abstract: An X-ray tube for greatly enhancing the output of photons relative to a standard tube includes a source of an electron beam focused on a target at an angle of approximately 10.degree. to produce high energy photons emitted at an angle along their centerline of 5.degree. to 15.degree., both angles referring to the surface of the target. Reduction of impurgement of scattered electrons on the tube window is affected in various ways such as use of a magnet to deflect electrons from the photon stream or locating the window out of alignment with the most intense scattered electrons. Scattered electrons are also absorbed by an essentially zero albedo shield disposed in the path of the majority of the scattered electrons not directed at the window.
    Type: Grant
    Filed: November 19, 1991
    Date of Patent: April 27, 1993
    Inventor: Michael Danos
  • Patent number: 5204891
    Abstract: An improved high performance x-ray tube having a rotating graphite anode therein and method of preparation thereof. The surface of a graphite anode body is oxidized in air for removing the surface damage caused during the machining of the anode body. The anode body is provided with a diffusion barrier layer of rhenium contiguously disposed on the substantially damage free surface of the anode body. An anode target layer is then deposited on top of the barrier layer.
    Type: Grant
    Filed: October 30, 1991
    Date of Patent: April 20, 1993
    Assignee: General Electric Company
    Inventors: David W. Woodruff, Minyoung Lee
  • Patent number: 5202910
    Abstract: Improved materials for the electrodes of arc discharge devices reduce arcing damage.The materials have a ductile-to-brittle transition temperature at or below the normal operating temperature of the devices.
    Type: Grant
    Filed: June 23, 1992
    Date of Patent: April 13, 1993
    Assignee: North American Philips Corporation
    Inventors: Phillip K. Ausburn, Loyce A. Turner
  • Patent number: 5185774
    Abstract: An x-ray tube construction comprising a housing and a shaft assembly mounted within the housing for rotational movement within the housing. An anode target is provided in the housing. A three-ball mounting is provided for mounting the anode target on the shaft assembly so that the anode target rotates with the shaft assembly. A cathode is disposed within the housing in the vicinity of the anode target. A voltage supply is connected to the anode target and to the cathode for accelerating electrons from the cathode to impinge upon the anode target to create x-rays. The three-ball mounting serves to minimize the transfer of heat from anode target to the shaft assembly. A motor drive is coupled to the shaft assembly for rotating the shaft assembly and the anode target carried thereby. A heat cage is disposed within the housing and surrounds the anode target. The heat cage has a window therein to permit the x-rays to pass therethrough.
    Type: Grant
    Filed: November 23, 1990
    Date of Patent: February 9, 1993
    Assignee: PXT Technology, Inc.
    Inventor: Heinrich F. Klostermann
  • Patent number: 5173931
    Abstract: The present invention is directed to a method and apparatus for generating x-rays employing a vacuum x-ray tube wherein the entire tube housing containing an x-ray emitting anode and an electron emitting cathode is rotated about an axis with means for focussing electrons from the cathode onto a region of the anode. Heat is conducted from the anode to an extended cooling surface remote from the anode by varied heat conduction tailored to produce a substantially uniform temperature over the cooling surface.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: December 22, 1992
    Inventor: Norman Pond
  • Patent number: 5159619
    Abstract: A high performance x-ray tube rotating target having a reactive barier layer between the substrate and the emissive coating and, if desired, a protective layer of molybdenum between the reactive barrier and the emissive coating is disclosed.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: October 27, 1992
    Assignee: General Electric Company
    Inventors: Mark G. Benz, Melvin R. Jackson, Robert J. Zabala, Karen A. Lou, Thomas C. Tiearney, Jr.
  • Patent number: 5157705
    Abstract: The invention relates to enhancing the thermal emissivity of metal X-ray tube anodes by means of applying an oxide coating to the anode. The oxide coating layer is formed of a mixture of zirconium oxide, titanium oxide, aluminum oxide and/or calcium oxide, with silicon oxide added from about 1-20% by weight of said oxide coating layer. Preferably, the coating includes from about 4-7% by weight of silicon oxide. The oxide coating layer is then applied to the anode pursuant to a standard method such as plasma spraying. The oxide coating, as formulated, displays improved layering characteristics over prior formulations while retaining good thermal emissivity and adhesive properties. Moreover, the formulation according to the invention enables an improved application to the anode of such oxides or oxide compounds over previous formulations, without negatively affecting the layer adhesion or thermal emission coefficient properties of the coating.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: October 20, 1992
    Assignee: Schwarzkopf Technologies Corporation
    Inventor: Wolfgang Hohenauer
  • Patent number: 5150397
    Abstract: A high thermal emittance coating for an x-ray tube anode target which permits broad application parameters and a stable and smooth coating. The coating is composed of ZrO.sub.2 present in an amount of 8% to 20% by weight and Al.sub.2 O.sub.3 and TiO.sub.2 present in an amount of 92% to 80% by weight with the Al.sub.2 O.sub.3 and TiO.sub.2 being present in a ratio in the range of 4 to 1. A preferable coating is composed of about 10% by weight of ZrO.sub.2 and 90% by weight of Al.sub.2 O.sub.3 and TiO.sub.2.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: September 22, 1992
    Assignee: General Electric Company
    Inventor: Michael J. Randzaao
  • Patent number: 5146483
    Abstract: A rotary anode stem tube is secured to a bearing by a coupling arrangement including a nested body and shaft, the shaft being thermally conductively coupled to the stem tube and the body being thermally conductively coupled to the bearing. The body and shaft have a relatively large interface region in facing spacing relation. Different positions of the interface region engage in thermally conductive relation in accordance with the temperature of the stem tube to selectively increase the thermal conductivity of the shaft to the body and selectively decrease the cooling time of the stem tube without an unacceptable increase in the bearing temperature.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: September 8, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Rolf Behling
  • Patent number: 5128977
    Abstract: An X-ray tube for greatly enhancing the output of photons relative to a standard tube includes a source of an electron beam focused on a target at an angle of approximately 10.degree. to produce high energy photons emitted at an angle along their centerline of 5.degree. to 15.degree., both angles referring to the surface of the target. Reduction of impurgement of scattered electrons on the tube window is affected in various ways such as use of a magnet to deflect electrons from the photon stream or locating the window out of alignment with the most intense scattered electrons. Scattered electrons are also absorbed by an essentially zero albedo shield disposed in the path of the majority of the scattered electrons not directed at the window.
    Type: Grant
    Filed: August 24, 1990
    Date of Patent: July 7, 1992
    Inventor: Michael Danos
  • Patent number: 5125020
    Abstract: The apparatus is an anode for an X-ray tube which is rotated at high speeds during operation. The anode include a plate of refractory material with high mechanical strength. On both faces of the plate are fixed two blocks of light weight refractory material. One of the blocks is formed of several sub-blocks fixed to one another through brazing. A layer of X-ray emitting mattering is deposited on the outer surface of these sub-blocks.
    Type: Grant
    Filed: November 27, 1990
    Date of Patent: June 23, 1992
    Assignee: General Electric CGR S.A.
    Inventors: Jean-Marie Penato, Michel Laurent, Philippe Thomas
  • Patent number: 5065419
    Abstract: The invention relates to an X-ray tube used to obtain radiological images in which sharpness and contrast are improved. To this end, the X-ray tube has an anode consisting, at least partially, of a massive layer made of an X-ray emitting material in which at least one hollow part demarcates a surface exposed to a beam of electrons.
    Type: Grant
    Filed: December 26, 1989
    Date of Patent: November 12, 1991
    Assignee: General Electric CGR S.A.
    Inventors: Jacques Leguen, Emile Gabbay
  • Patent number: RE35383
    Abstract: An interstitial X-ray needle includes an elongated X-ray tube coupled to an electron emitter at one end of the tube, with a converter element being disposed at a tip of the other end of the tube for converting emitted electrons into X-ray; a solenoid coil wound around the tube for providing a magnetic field that confines the emitted electrons within a narrow beam; an elongated outer casing enclosing the tube and coil; and a pipe coaxially disposed between the casing and the tube for defining an inner annular flow chamber between the tip of the tube and a coolant inlet in the casing and an outer annular flow chamber between the tip of the tube and a coolant outlet in the casing.
    Type: Grant
    Filed: July 5, 1994
    Date of Patent: November 26, 1996
    Assignee: The Titan Corporation
    Inventors: Robert B. Miller, John R. Smith, Carl A. Muehlenweg