Applied Directly By Fluid Pressure Patents (Class 73/807)
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Patent number: 11598704Abstract: A device and method for testing a rock specimen in order to determine the fracture toughness (KIC) thereof. The device comprises: a frame; a hydraulic pressure testing rig supported by the frame and comprising a pressure gauge, a lever and a pressure diaphragm; a storage tank for storing hydraulic fluid and supported by the frame; and a pressure chamber supported by the frame, in which the test specimen is placed to be subjected to hydrostatic pressure through conduits that connect said pressure chamber with the storage tank in fluid communication.Type: GrantFiled: November 5, 2020Date of Patent: March 7, 2023Assignees: YPF TECNOLOGÍA S.A., CONSEJO NACIONAL DE INVESTIGACIONES CIENTÍFICAS Y TÉCNICAS (CONICET)Inventors: Santiago Serebrinsky, Humberto Celleri, Walter Morris, Anibal Márquez, Juan Belmonte
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Patent number: 11243152Abstract: A method and apparatus for testing rings cut from pipes for use in making subsea pipelines are described. The method for determining the whether a test ring is correctly assembled in a test chamber for testing pipes for use in making subsea pipelines comprises: mounting a test ring in a pressure chamber such that the ends of the test ring forms seals with opposing surfaces of the chamber to isolate the inside of the test ring from the outside; providing means for measuring the displacement of the test ring; providing means for measuring a force applied to the inner surface of the test ring; applying a force to the inner surface of the test ring; and using the displacement measurement and force measurements to determine whether the test ring is correctly mounted in the pressure chamber.Type: GrantFiled: June 19, 2018Date of Patent: February 8, 2022Assignee: VERDERG PIPE TECHNOLOGY LIMITEDInventors: Peter Roberts, Alastair Walker
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Patent number: 10844711Abstract: A triaxial test system and method including a core sample, high temperature-resistant drains disposed around the core sample, and at least one and optionally two high temperature-resistant elastomeric sealing membranes disposed about the drains and sample. Preferred for use is a shear-resistant and high temperature-resistant sealing membrane such as a Viton membrane, optionally in combination with a silicone high temperature-resistant sealing membrane. The system and methods can be used to test core samples in compliance with ASTM standard test methods for triaxial compression tests, at temperatures of between about 100° C. and 200° C., optionally between about 175° C. and 200° C., for extended periods of time, for example several days or longer.Type: GrantFiled: May 29, 2018Date of Patent: November 24, 2020Assignee: BIG GUNS ENERGY SERVICES INC.Inventors: Peter Cooper, Ming Liu, Dickson Lee
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Patent number: 9476171Abstract: The invention provides a construction comprising a structural element and at least one cable (101) arranged in tension to carry at least a part of the weight of the structural element. The cable defines an outer surface (102) onto which at least one strake (104) forms a protrusion for reducing rain and wind induced vibrations. The strake has a height being a distance from a strake root part connected to the outer surface of the cable and a strake end part terminating the strake outwards away from the cable, and the strake has a width being transverse to the height, the width decreasing in the direction from the strake root part towards the strake end part. The height is less than 5 percent of the diameter of the cable. Furthermore, the strake comprises a first strake surface portion facing away from the cable, which first strake surface portion is concave or straight.Type: GrantFiled: June 28, 2013Date of Patent: October 25, 2016Assignee: Danmarks Tekniske UniversitetInventors: Christos Thomas Georgakis, Kenneth Kleissl
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Patent number: 9476172Abstract: The invention provides a construction comprising a structural element and at least one cable (100) arranged in tension to carry at least a part of the weight of the structural element. The cable defines an outer surface (102) onto which a plurality of strakes (104) form protrusions for reducing rain and wind induced vibrations. Each strake has a height being a distance from a strake root part connected to the outer surface of the cable and a strake end part terminating the strake outwards form the cable, a width being transverse to the height, and a length transverse to the height and width and along which length the strake is connected to the cable. The length of each strake is shorter than the circumference of the outer surface, and the height is less than 5 percent of the diameter of the cable.Type: GrantFiled: June 28, 2013Date of Patent: October 25, 2016Assignee: Danmarks Tekniske UniversitetInventors: Christos Thomas Georgakis, Kenneth Kleissl
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Patent number: 8465295Abstract: A fluid percussion system for modeling penetrating brain injury includes a fluid percussion device that takes inputs in the form of pressurized gas and electrical signals from a computer and outputs a single hydraulic pulse, or multiple hydraulic pulses in quick succession. The fluid percussion device may include a pneumatic cylinder assembly and a hydraulic cylinder assembly that is actuated by the pneumatic cylinder assembly to produce the hydraulic pulse(s) of pressurized fluid. Each pulse may be used to rapidly inflate and deflate an attached balloon (representing a brain penetrating device). The balloon may be inserted in a test specimen, and the rapid inflation and deflation of the balloon creates a lesion that simulates a penetrating brain injury. A calibration system that employs an optical sensor may be used to determine maximum balloon diameter achieved during rapid inflation.Type: GrantFiled: February 6, 2008Date of Patent: June 18, 2013Assignee: The MITRE CorporationInventors: Steven M. Taskovics, Brett H. Kobelin, Marc S. Pepi, Steven R. Mitchell
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Apparatus and method for fatigue testing of a material specimen in a high-pressure fluid environment
Patent number: 8453515Abstract: The invention provides fatigue testing of a material specimen while the specimen is disposed in a high pressure fluid environment. A specimen is placed between receivers in an end cap of a vessel and a piston that is moveable within the vessel. Pressurized fluid is provided to compression and tension chambers defined between the piston and the vessel. When the pressure in the compression chamber is greater than the pressure in the tension chamber, the specimen is subjected to a compression force. When the pressure in the tension chamber is greater than the pressure in the compression chamber, the specimen is subjected to a tension force. While the specimen is subjected to either force, it is also surrounded by the pressurized fluid in the tension chamber. In some examples, the specimen is surrounded by hydrogen.Type: GrantFiled: September 3, 2010Date of Patent: June 4, 2013Assignee: UT-BaHelle, LLCInventors: Jy-An Wang, Zhili Feng, Lawrence M. Anovitz, Kenneth C. Liu -
Patent number: 8234930Abstract: A method of determining fatigue of a pressure-resistant component for high-pressure hydrogen made of a ferritic steel and provided in a high-pressure hydrogen gas environment is provided wherein when the material of the ferritic steel in the air has an ultimate tensile strength Su in the range of 958-1,144 MPa and the hydrogen gas environment has a pressure in a range to 45 MPa, then a fatigue strength in a gaseous hydrogen SH (MPa) for the pressure-resistant component provided in the high-pressure hydrogen gas environment is obtained by using equation (1): SH (MPa)=2,577?1.8925×Su (MPa). The influence of a high-pressure hydrogen gas environment on the pressure-resistant component for high-pressure hydrogen is determined based on the fatigue strength obtained by using the equation (1).Type: GrantFiled: July 18, 2008Date of Patent: August 7, 2012Assignee: The Japan Steel Works, Ltd.Inventors: Yoru Wada, Ryoji Ishigaki, Yasuhiko Tanaka
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Patent number: 8191430Abstract: A method of testing pipes for use in making subsea pipelines comprises cutting a ring from one or more pipes of the type used to make the pipeline; forming flat, substantially parallel surfaces on the ends of the ring; providing means for measuring strain and deformation of the ring; mounting the ring in a pressure chamber such that the ends of the ring form seals with opposing walls of the chamber to isolate the inside of the ring from the outside; increasing the pressure outside the ring and measuring the strain and deformation on the ring as the pressure increases; and using the deformation and strain measurements to determine a wall thickness for pipes to be used for the pipeline.Type: GrantFiled: March 17, 2008Date of Patent: June 5, 2012Assignee: VerdErg LtdInventors: Peter Miles Roberts, Alastair Chalmers Walker
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Apparatus and Method for Fatigue Testing of a Material Specimen in a High-Pressure Fluid Environment
Publication number: 20120055258Abstract: Provided are several examples of apparatuses and methods for applying loads to material specimens in pressurized fluid environments. The apparatuses use the fluid pressure as the force for applying the loads to the specimens.Type: ApplicationFiled: September 3, 2010Publication date: March 8, 2012Applicant: UT-BATTELLE, LLCInventors: Jy-An Wang, Zhili Feng, Lawrence M. Anovitz, Kenneth C. Liu -
Publication number: 20110167921Abstract: A method of determining fatigue of a pressure-resistant component for high-pressure hydrogen made of a ferritic steel and provided in a high-pressure hydrogen gas environment is provided wherein when the material of the ferritic steel in the air has an ultimate tensile strength Su in the range of 958-1,144 MPa and the hydrogen gas environment has a pressure in a range to 45 MPa, then a fatigue strength in a gaseous hydrogen SH (MPa) for the pressure-resistant component provided in the high-pressure hydrogen gas environment is obtained by using equation (1): SH (MPa)=2,577?1.8925×Su (MPa). The influence of a high-pressure hydrogen gas environment on the pressure-resistant component for high-pressure hydrogen is determined based on the fatigue strength obtained by using the equation (1).Type: ApplicationFiled: July 18, 2008Publication date: July 14, 2011Applicant: THE JAPAN STEEL WORKS, LTD.Inventors: Yoru Wada, Ryoji Ishigaki, Yasuhiko Tanaka
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Patent number: 7905150Abstract: The invention relates to a test device for simultaneously exposing a disk-shaped test specimen to a flowing and pressurized test gas and mechanical load as well as an associated test method. The test device is comprised of the following components: a specimen seat, which is designed in such a way that an edge area of the test specimen rests on the specimen seat and an inner area of the test specimen is accessible from its upper side and lower side; a ram arranged above the specimen seat, with which a presettable mechanical load can be exerted on the upper side of the test specimen; and a gas feed plate arranged beneath the specimen seat, with which the test gas can be conveyed to the lower side of the test specimen.Type: GrantFiled: July 23, 2008Date of Patent: March 15, 2011Assignee: Bam Dundesanstalt fuer Materialforschung und-PruefungInventors: Axel Kranzmann, Daniela Hünert
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Patent number: 7647839Abstract: A unit dedicated to mechanically loading a tubular sample. At least one packer is housed in a sample at a test zone, having a longitudinal extension greater than that of the test zone and including i) a first pressure mechanism to cause local variation in the diameter of at least a first portion of the packer so as to apply the packer against an internal surface of the sample at the test zone, ii) a second pressure mechanism exerting a first selected internal pressure over a portion of the internal surface located at a second portion of the packer, and/or iii) a third pressure mechanism to cooperate with at least one plug member attached to the sample at a distance from one end of the packer to define a zone of action, to exert on the sample a second selected internal pressure at the zone of action.Type: GrantFiled: February 23, 2006Date of Patent: January 19, 2010Assignee: Vallourec Mannesmann Oil & Gas FranceInventors: Didier David, Thierry Noel, Gabriel Roussie
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Patent number: 7540200Abstract: This invention relates generally to testing apparatus and methodology for measuring fluid dynamic properties of structures within fluid flows. One embodiment includes a fluid induced motion testing apparatus of the type which includes a test rig suitable for holding a test body in a fluid body. The apparatus may include any of an actuator suitable for producing a force upon the test body; a turbulence generator located in the fluid body up current from the test body suitable for generating a turbulent flow field with uniform turbulence intensity across the fluid body-test body interface, the turbulent flow field including dominate vortical structures, the axis of the vortical structures about parallel to the longitudinal axis of the test body; or a test body adjuster suitable for adjusting the test body relative to the fluid current in four or more increments, thereby enabling multiple headings of the test body to be tested against the current of the fluid body.Type: GrantFiled: May 27, 2004Date of Patent: June 2, 2009Assignee: ExxonMobil Upstream Research CompanyInventors: Tin-Woo Yung, Scott T. Slocum, Robert E. Sandstrom, Zhong Ding, Leif Smitt
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Patent number: 7069792Abstract: Apparatus for locating adhesive failure of sealant joints. Useful for determination of the quality of sealant joints in structures, especially curtain wall buildings. A substantially constant pressure probe is utilized to displace roughly a middle third of a sealant bead that is located along a sealant joint having longitudinal axis and spanning a gap between adjacent substrates, using a predetermined force calibrated to provide a preselected elongation of a particular type of sealant. The testing apparatus has a frame, a first fluid cylinder having an first end wall, a first tubular cylinder wall, a first piston, and a first shaft. The first shaft is response to movement of the first piston. The first shaft has a probe affixed thereto.Type: GrantFiled: August 8, 2002Date of Patent: July 4, 2006Inventors: Donald F. Casad, Daniel N. Huff, Dale R. Herbert
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Patent number: 6983660Abstract: An apparatus and method for measuring the fatigue strength and fatigue damage of structures and predicting the service life remaining in the structure being tested. The apparatus is a specially designed fatigue gauge that contains breakable ligaments of either variable length to measure fatigue strength or fatigue damage of metallic, polymeric and composite materials or the same length but different composition to measure the fatigue strength and fatigue damage of certain composite materials.Type: GrantFiled: November 3, 2003Date of Patent: January 10, 2006Inventor: Young Wuk Kwon
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Patent number: 6952959Abstract: This invention provides a method of designing a suitable heat seal width which is more resistant to unsealing than conventional heat-sealing, which involves the steps of; (1) heat-sealing a test piece of a sheet to be heat-sealed at a temperature lower than the fusion temperature of a heat seal portion of the sheet, (2) heat-sealing another test piece of the sheet at a temperature at or higher than the fusion temperature, (3) pulling to peel a heat-sealed portion of each test piece, and measuring the pull strength variation with peel length, (4) calculating the peel energy in various peel length as of the test piece heat-sealed at a temperature lower than the fusion temperature of the heat seal portion of the sheet by integrating the pull strength variation, (5) calculating the peel energy of the test piece heat-sealed at the temperature at or higher than the fusion temperature by integrating the pull strength variation up to rupture at a heat-sealed portion, and (6) setting the heat seal width at a peel lengType: GrantFiled: February 5, 2004Date of Patent: October 11, 2005Inventor: Kazuo Hishinuma
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Publication number: 20040168521Abstract: For use in the monitoring of a tubular member (1) having at least a helically wound reinforcement layer (10), the invention provides a method of mounting a sensor arrangement (17, 18), wherein the reinforcement layer is formed with a groove (16) which is filled with a liquid material (19), such as an epoxy type, and wherein the sensor arrangement is passed into the liquid material by means of a pressure applied by a roller prior to the solidification of the liquid material. In a preferred embodiment, the groove is formed in the reinforcement layer before this is helically wound on the tubular member. Hereby, the sensor arrangement is arranged well-protected without any risk of damage, which may e.g. occur if the tubular member is of the unbonded type, where the reinforcement layer may consist of two layers that may move relative to each other.Type: ApplicationFiled: April 19, 2004Publication date: September 2, 2004Inventor: Martin Andersen
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Publication number: 20040069070Abstract: A load sensing hydraulic system includes two pumps, at least one hydraulic fluid consumer, and a pressure balance circuit. In the case of no demand from the consumer, hydraulic fluid flows from the pumps through the pressure balance circuit and to tank. In the case of demand from the consumer for hydraulic fluid at a flow rate less than or equal to the flow rate provided by the first pump, hydraulic fluid from the first pump flows to the consumer, and hydraulic fluid from the second pump flows to the tank. In the case of a demand from the consumer for hydraulic fluid at a flow rate greater than the capacity of the first pump, hydraulic fluid from both pumps flow to the consumer.Type: ApplicationFiled: April 14, 2003Publication date: April 15, 2004Inventors: Francis Cazier, Thierry Delort, Bertrand Duval, Gilles Hoessler, Patrick Lorriette
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Patent number: 6595068Abstract: A hollow cylindrical tester uses an inflatable membrane to apply hoop stress to a hollow cylindrical sample. The compact device includes a frame that holds a sample around the inflatable membrane. The membrane is preferably inflated via fluid pressure and the fluid pressure preferably is monitored to determined pressure at critical points in testing procedures. Pressures of fluids within the membrane are also monitored. In a preferred structure, a piston and cylinder pressure injector operatively connected to the membrane is monitored for amount of piston travel and a pressure meter monitors fluid pressure. The preferred structure includes shaped opposing platens to seal the membrane within a cylinder sample being tested, a post failure restraint cylinder, and a cooling fluid bath.Type: GrantFiled: February 22, 2001Date of Patent: July 22, 2003Inventors: Thomas E. Brovold, William G. Buttlar
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Publication number: 20020157454Abstract: An inspection machine by compression for inspecting a ceramic sample (1), in which the ceramic sample (1) is disposed in a cylindrical container (8) via an elastic sheet (9), and the ceramic sample (1) is compressed by a hydrostatic-pressure-applying medium injected between the cylindrical container (8) and the elastic sheet (9). A rubber material having a thickness of 5 mm or less and a hardness of 30-50° is employed as the elastic sheet (9). Since the elastic sheet interposed was made thin and given a predetermined hardness to eliminate pressure decrease almost completely, pressurization can be conducted with high accuracy even under low pressure.Type: ApplicationFiled: October 24, 2001Publication date: October 31, 2002Inventors: Shinichi Shimada, Shinichi Naruse, Takashi Teraguchi
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Publication number: 20020139172Abstract: A device which may be carried by and part of an unmanned vehicle which measures characteristics of manure of animals such as dairy cows that are milked and fed in a stable provided for them. The vehicle is supported by three driven wheels and carries a mechanism for analyzing manure which comprises a compression chamber for receiving a manure sample. A sieve is provided on one side of the chamber and a piston forces the manure sample through the sieve. By measuring the pressure required to squeeze the manure sample through the sieve, characteristics such as the fibrousness and the viscosity of the manure sample can be determined. The vehicle also carries an identification instrumentality for identifying the animal that provided the manure sample and may carry a temperature sensor and an inertia meter. It is operatively associated with a computer which registers data provided from analysis of each animal's manure sample and provides same as displayable data.Type: ApplicationFiled: January 22, 2001Publication date: October 3, 2002Applicant: LELY RESEARCH HODING AGInventor: Karel Van Den Berg
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Patent number: 5882929Abstract: Apparatus and methods are disclosed for maturing a biopolymer tissue construct in vitro prior to use as a replacement construct in vivo as, for example, a graft, implant, or prosthesis. The tissue is seeded with specific cells, exposed to a maturation fluid, such as a synovial-like fluid containing hyaluronic acid, and subjected to selected conditioning and maturation forces, which can include frictional forces, shear forces, and compressive pressure. The tissue is mounted on a first support element and a second surface applies a selected force to the tissue. This maturation process occurs within a maturation chamber. The resultant matured replacement tissue construct is intended to provide a replacement tissue that is more readily integrable in vivo to produce a more durable and functional replacement tissue.Type: GrantFiled: April 7, 1998Date of Patent: March 16, 1999Assignee: Tissue Engineering, Inc.Inventors: Timothy W. Fofonoff, Eugene Bell
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Patent number: 5431045Abstract: The equipment for measuring on earth the thrust of thrusters for use in space comprises a balance (1) and a measuring means (11) which is associated with the balance in order to measure the thrust exerted by the thruster (P). The balance (1) is provided with a target (13) at which the exhaust jet from the thruster (P) is directed, whereas the thruster is mechanically free from the structure of the balance and the measuring means (11) measures the force applied to the balance in order to balance the thrust exerted on the balance by the jet from the thruster. (FIG.Type: GrantFiled: April 28, 1994Date of Patent: July 11, 1995Assignee: Proel Technologie S.p.A.Inventor: Gianfranco Cirri
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Patent number: 5417103Abstract: This invention relates to a method of determination of the deformation of the surface or subsurface of the earth resulting from an applied pressure change at a selected point, at a selected depth, in the earth, by measuring at least one physical parameter of the deformation above the point of application of pressure change. The method involves positioning a plurality of tiltmeters on or below the surface of the earth above the point of application of pressure change arranged in a known array, and measuring the change of angle of tilt of earth's surface or subsurface at the point of placement of each sensor while varying the pressure and flow rate of fluid into or out of the earth at the selected point. This invention further teaches how the individual values of incremental tilt at selected points on or below the earth's surface can be processed to determine material properties at selected points in the earth.Type: GrantFiled: November 10, 1993Date of Patent: May 23, 1995Inventors: Roger J. Hunter, Richard F. Reinke
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Patent number: 5375453Abstract: A method and apparatus for approximating the life of a gasket used in a predetermined environment is provided which allows for the long-term exposure to the environment to be simulated over a shortened period of time. The method and apparatus utilize the steps of placing a gasket sample in a test assembly, clamping the gasket sample within the test assembly at a predetermined clamping pressure whereby a chamber is formed within the interior of the gasket sample, filling the chamber with a gas at a predetermined pressure from a gas fill system, changing the temperature of the gasket sample over a predetermined number of temperature cycles, and measuring the amount of the gas which leaks from the chamber. The apparatus may also include a pressure control system for changing the pressure within the chamber over a predetermined number of pressure cycles or in response to predetermined temperature conditions.Type: GrantFiled: August 31, 1993Date of Patent: December 27, 1994Assignee: Westinghouse Electric CorporationInventors: George E. Rudd, Rajender K. Sadhir, Samuel A. Withrow, Dong S. Kim, Daniel L. Price
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Patent number: 4972721Abstract: A dynamic vascular compliance tester (change in radius with change in pressure) comprises an oscillatorily driven bellows to simulate pulsing a fluid pressure within a test specimen and a method of use thereof. The tester includes a high frequency pressure transducer and a pair of linear voltage-to-displacement transducers ("LVDT") providing outputs that are utilized cooperatively to determine the compliance of a test specimen. A first LVDT measures the volume of fluid in each pulse provided by the bellows and a second LVDT measures the change in length of the test specimen during the pulse. The tester also includes an offset drive mechanism that is operably adjustable such that the volume of fluid passing into the test specimen can be altered as desired.Type: GrantFiled: January 23, 1990Date of Patent: November 27, 1990Assignee: Dynatek Laboratories, Inc.Inventor: James C. Conti
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Patent number: 4910997Abstract: Apparatus for applying a fluctuating stress to, for example, a gable end of a house includes a pressure enclosure. An air compressor is connected to the pressure enclosure via a series of gauged valves whose positions are continuously variable between limiting positions where the air compressor supplies all its output to, or takes all its output from the pressure enclosure. The effects of gusty winds can thus be simulated.Type: GrantFiled: January 24, 1989Date of Patent: March 27, 1990Assignee: The Secretary of State of the EnvironmentInventor: Nicholas J. Cook
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Patent number: 4845996Abstract: A test system for caissons, piles and the like provides an improved way of testing the load bearing capabilities of such inground foundation elements. The test method involves supporting an inertial mass, e.g. of concrete rings, on the upper end of a columnar foundation element that is installed in the ground and generating in a chamber defined between the underside of the inertial mass and the upper end of the foundation element over a limited duration a propellant gas pressure sufficient to accelerate the inertial mass upwards away from the upper end of the foundation element and at the same time to produce a downwards reaction force of a predetermined desired magnitude on the element. The rate of increase of fluid pressure is controlled such that the reaction force does not damage the foundation element. The magnitude of the downwards force and the response of the foundation element are measured by suitable instrumentation.Type: GrantFiled: May 4, 1988Date of Patent: July 11, 1989Assignee: Berminghammer Corporation LimitedInventor: Patrick Bermingham
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Patent number: 4579003Abstract: An instrument for testing earthen samples under triaxial load conditions includes an upwardly extending cylindrical housing with two access windows formed in the side thereof, and a transparent cylindrical sleeve adapted to be slidably received about the housing to seal the chamber within. A lower stage is supported on a laterally translatable bearing block, and connected to a double-acting horizontal hydraulic ram. An upper stage is disposed in superjacent opposition to the lower stage, and is connected to the lower end of a vertical hydraulic ram supported atop the housing. The stages include shallow sockets adapted to receive sample platens in vertical alignment with the vertical ram. The platens each include peripheral grooves adapted to be engaged by swing clamps extending from each stage. Each platen includes a filter stone portion adapted to contact a core sample disposed between the platens, with a fluid channel extending radially through each platen to the filter stone.Type: GrantFiled: January 22, 1985Date of Patent: April 1, 1986Inventor: Brodie D. Riley
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Patent number: 4566868Abstract: A liquid pressure source, e.g. for use in soil mechanics laboratories, has a piston-cylinder unit driven by a stepper motor: a pressure transducer indicates the liquid pressure and a digital feedback control unit responds to generate stepping pulses to maintain a desired pressure. A step counter can be included to provide an accurate indication of volume change, and backlash compensation may be provided by arranging that the counter, following a direction change, ignores motor steps until a pressure change occurs.Type: GrantFiled: September 11, 1981Date of Patent: January 28, 1986Assignee: Geotechnical Digital Systems LimitedInventor: Bruce K. Menzies
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Patent number: 4272994Abstract: A method and apparatus for maintaining a constant elevated liquid pressure in a small vessel by pressuring with liquid the small vessel and a larger vessel in open communication therewith. The larger vessel, preferably, has a volume of about 20 to about 100 times the volume of the smaller vessel. In one embodiment the mechanical pressuring is reapplied to maintain a constant pressure in the vessels. In another embodiment, the temperature of the liquid in the larger vessel is manipulated to maintain pressure in the vessels.Type: GrantFiled: June 1, 1979Date of Patent: June 16, 1981Assignee: Phillips Petroleum CompanyInventor: Edwin E. Reed