Patents Assigned to Oval Corporation
  • Publication number: 20110193003
    Abstract: A torque limiter which can detect torque of both opening and closing of a valve and in which different torque values for opening and closing of the valve can be easily set. The torque limiter is provided with a torque arm having a connection section which is connected to a drive side gear and an intermediate gear and also having an arm section projecting from the connection section; an open side spring portion and a closure side spring means which apply spring force balancing with force acting, in proportion to torque of a load in opening and closing operation of the valve, in the direction of a tangential line at the meshing point of the intermediate gear; an open side torque detection switch and a closure side torque detection switch which are, when torque of a load in opening and closing operation of the valve exceeds a predetermined value, operated by the arm section; and a torque limiter shaft passed through the open and closure side spring portion.
    Type: Application
    Filed: April 20, 2009
    Publication date: August 11, 2011
    Applicant: OVAL Corporation
    Inventors: Tomonari Tachikawa, Isamu Hashimoto
  • Patent number: 7946185
    Abstract: A converter pulse width shaping circuit (6) according to the present invention is provided between a waveform shaping apparatus (4) and an erroneous output preventing apparatus (5) that are provided between a flow rate detecting portion (1) and a flow rate metering mechanism (3). When high frequency pulse signals of a frequency not lower than a predetermined value are successively input, the converter pulse width shaping circuit (6) combines those high frequency pulse signals to convert them to a low frequency pulse signal, which is then output to the erroneous output preventing apparatus (5) having a low-cut function. In the present invention, a vortex flow meter is made up of a converter (2) including the converter pulse width shaping circuit (6) described above.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: May 24, 2011
    Assignee: Oval Corporation
    Inventors: Kenji Washio, Takashi Hirose
  • Patent number: 7905141
    Abstract: One pressure difference detection connecting path (71) and another pressure difference detection connecting path (72) are formed so as to be arranged at a predetermined interval in a longitudinal direction. Further, the one pressure difference detection connecting path (71) is formed so as to be connected in front of a continuation center position (70) of a second inflow path (67) and a first inflow path (43). Further, the other pressure difference detection connecting path (72) is formed so as to be connected behind a continuation center position (69) of a second outflow path (66) and a first outflow path (44).
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: March 15, 2011
    Assignee: Oval Corporation
    Inventor: Takeshi Wakamatsu
  • Patent number: 7905142
    Abstract: A volumetric flowmeter (1) is equipped with a detachable pump unit (2), a main body casing (3) accommodating the pump unit (2), and a cover member (4). The main body casing (3) is equipped with a front side main body casing (8) accommodating the pump unit (2) and integrated with a differential pressure detector (6), and a rear side main body casing (10) connected to the front side main body casing (8) and allowing mounting therewithin of a servomotor (9) constituting a main body of a shaft driving unit (5). The pump unit (2) is inserted into a unit accommodating recess (11) of the front side main body casing (8) and is then covered with the cover member (4) to be thereby completely accommodated.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: March 15, 2011
    Assignee: Oval Corporation
    Inventor: Takeshi Wakamatsu
  • Patent number: 7895904
    Abstract: A multi-vortex flowmeter includes a vortex flowmeter for measurement by volume flow rate and a thermal flowmeter for measurement by mass flow rate to selectively use the two flowmeters according to the flow rate of fluid to be measured flowing through a flow channel. The multi-vortex flowmeter has a switching point between two flowmeters based on the mass flow rate. A mass flow rate Qm at the switching point in a range larger than the minimum flow rate of a vortex flowmeter and smaller than the maximum flow rate of a thermal flowmeter is determined by: Qm=K3*?P. Alternatively, a volume flow rate Q at the switching point in a range larger than the minimum flow rate of a vortex flowmeter and smaller than the maximum flow rate of a thermal flowmeter is determined by: Q=K1/?P.
    Type: Grant
    Filed: April 23, 2007
    Date of Patent: March 1, 2011
    Assignee: Oval Corporation
    Inventors: Naoki Matsubara, Kohji Takahashi
  • Patent number: 7870785
    Abstract: A position displacement flowmeter having a pair of non-circular gears in a rolling contact on a pitch line without slippage. The positive displacement flowmeter comprises a casing and a pair of rotors provided in the casing and rotatable around its center axes. The pair of rotors, have a tooth profile curve which is an oval pitch curve itself having a trajectory of contact points on the pitch line, and they satisfy a condition of r1+r2=K=const r1 d?1=r2 d?2, and a moving radius of the oval pitch curve is given by ri=a/(1?b cos n?i) (i=1, 2), where “ri (i=1, 2)” is the moving radius that is a distance from a center of rotation to the oval pitch curve, “a” is a homothetic coefficient, “b” is a flattening, “n” is a number of lobes, and “?i (i=1, 2) is a moving angle.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: January 18, 2011
    Assignee: Oval Corporation
    Inventors: Seigo Ono, Katsuichi Uchida
  • Patent number: 7861602
    Abstract: A temperature-sensitive sensor (21) and a heating temperature-sensitive sensor (22) are fixed in position in a liquid-tight fashion by welding, with the metal tubular bodies (36 and 37) being inserted into the tubular body insertion holes (19 and 20) of a vortex detector (4). Sealing performance is secured without using any O-ring. The temperature-sensitive sensor (21) and the heating temperature-sensitive sensor (22) respectively have lead wires (42 and 43) held together with the lead wires (27) of a vortex detection sensor (11) within the internal space (35), and the lead wires (27, 42, and 43) thus held together are led out toward the flow rate converter (not shown) via a metal pipe (34). Since the lead wires (27, 42, and 43) are held together within the internal space (35) and led out toward the flow rate converter via the metal pipe (34), there is involved only one joint portion between the sensors and the flow rate converter. With this structure, explosion-proof performance can be attained easily.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: January 4, 2011
    Assignee: Oval Corporation
    Inventor: Naoki Matsubara
  • Publication number: 20100307234
    Abstract: An ideal positive displacement flowmeter which has a pair of helical gears given by using oval pitch curve as reference rack tooth profile, with the tooth height ratio of the reference rack tooth profile even with a small number of teeth being set to ? m/4 which is a logical limit for the tooth height ratio of a one-point continuous contact tooth profile and which has no confinement phenomenon between tooth profiles. The positive displacement flowmeter has a pair of helical gears (1, 2) in a casing (3). The reference rack tooth profile of the pair of helical gears (1, 2) is an oval pitch curve of two or less leaves. The moving radius of the oval pitch curve is expressed by ?=a/(1?b cos n?), where ? is a moving radius which is a distance between the center of rotation and the oval pitch curve, “a” is a similarity factor, “b” is a degree of flatness, n (n?2) is the number of leaves, and ? is an argument.
    Type: Application
    Filed: May 23, 2008
    Publication date: December 9, 2010
    Applicant: OVAL CORPORATION
    Inventors: Seigo Ono, Katsuichi Uchida
  • Publication number: 20100281970
    Abstract: A position displacement flowmeter having a pair of non-circular gears in a rolling contact on a pitch line without slippage. The positive displacement flowmeter comprises a casing and a pair of rotors provided in the casing and rotatable around its center axes. The pair of rotors have a tooth profile curve which is an oval pitch curve itself having a trajectory of contact points on the pitch line, and they satisfy a condition of r1+r2=K=const r1 d?1=r2 d?2, and a moving radius of the oval pitch curve is given by ri=a/(1?bcosn?i) (i=1, 2), where “ri(i=1, 2)” is the moving radius that is a distance from a center of rotation to the oval pitch curve, “a” is a homothetic coefficient, “b” is a flattening, “n” is a number of lobes, and “?i(i=1, 2) is a moving angle.
    Type: Application
    Filed: March 6, 2008
    Publication date: November 11, 2010
    Applicant: Oval Corporation
    Inventors: Seigo Ono, Katsuichi Uchida
  • Patent number: 7827869
    Abstract: In order to extract a part of a three-phase flow from a pipe line, a pair of communication pipes, which are connected to upstream and downstream sides of an orifice provided in the pipe line, and a gas-liquid extraction tank are used. Flowing of a slag flow or the like into the pipe line causes a periodical change in a pressure difference between input and output sides of the orifice. This causes extraction of gas-liquid and discharge mainly of gas to be simultaneously effected in the pair of communication pipes and the gas-liquid extraction tank. Within the gas-liquid extraction tank, the gas-liquid is forcibly shaken horizontally, vertically, etc. for agitating, whereby gas-liquid of high liquid-phase rate remains. Then, the gas is removed from this gas-liquid of high liquid-phase rate to thereby extract mixture liquid, which is accumulated in a liquid storage tank. The mixture liquid flows from the liquid storage tank in an amount required at a Coriolis meter.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: November 9, 2010
    Assignee: Oval Corporation
    Inventors: Hirokazu Kitami, Hiraku Kawaoto
  • Patent number: 7739920
    Abstract: A first inlet portion, a second inlet portion, a first outlet portion, and a second outlet portion are fixed to a fixing member, and a connecting tube portion is provided between the first outlet portion and the second inlet portion. Further, the first inlet portion and the second inlet portion 6 are arranged in a non-parallel state such that the distance between the two increases as they depart from the fixing member. The first outlet portion and the second outlet portion are similarly arranged in a non-parallel state, the first inlet portion and the second inlet portion and the first outlet portion and the second outlet portion being arranged symmetrically. Further, the first outlet portion, the second inlet portion, and the connecting tube portion are arranged such that their three tube axes are in a straight line.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: June 22, 2010
    Assignee: Oval Corporation
    Inventors: Hirokazu Kitami, Yuichi Nakao, Norio Sukemura
  • Patent number: 7726202
    Abstract: A tertiary mode vibration type Coriolis flowmeter includes a flow tube, a drive device driving the flow tube, and a pair of vibration detecting sensors detecting a phase difference in proportion to a Colioris force acting on the flow tube. The drive device drives the flow tube by bending vibration in a tertiary mode. The flow tube further comprises an approximately loop-shaped body part. A pair of parallel leg parts deflected in a direction approximately orthogonal to the vibrating direction of both end parts of the body part, namely, to the outside of the both end parts are formed continuously with the both end parts of the body part. Fixed end parts supporting the flow tube are formed at the leg parts.
    Type: Grant
    Filed: January 13, 2005
    Date of Patent: June 1, 2010
    Assignee: Oval Corporation
    Inventor: Yuichi Nakao
  • Patent number: 7698956
    Abstract: A Coriolis flow meter (11) with a vibrating direction restriction means includes flow tubes (13, 13), a drive means (14) for driving the flow tubes (13, 13), and phase difference detection means (15, 15) for detecting a phase difference in proportion to a Coriolis force. The Coriolis flow meter further includes plate springs (16, 16) functioning as vibrating direction restriction means, and a flow tube fixing member (17) also functioning as a vibrating direction restriction means and serving to fix the flow tubes (13, 13) in position.
    Type: Grant
    Filed: February 26, 2007
    Date of Patent: April 20, 2010
    Assignee: Oval Corporation
    Inventor: Yuichi Nakao
  • Patent number: 7694585
    Abstract: A straight tube type Coriolis flowmeter is equipped with a straight-tube-type flow tube, a drive device for driving by a tertiary mode vibration, a pair of detection unit for detecting a phase difference proportional to a Coriolis force, a pedestal having rigidity, and elastic connection members having elasticity. Assuming that an axial direction of the flow tube is a Z-axis, that a driving direction of the drive device is an X-axis, and that a direction orthogonal to the Z-axis and the X-axis is a Y-axis, the elastic connection members are of a structure exhibiting lower rigidity in the Z-axis direction than in the X-axis direction and the Y-axis direction, and exhibiting lower rigidity in a direction of rotation around the Y-axis than in a direction of rotation around the Z-axis and a direction of rotation around the X-axis.
    Type: Grant
    Filed: September 8, 2006
    Date of Patent: April 13, 2010
    Assignee: Oval Corporation
    Inventor: Yuichi Nakao
  • Publication number: 20090289810
    Abstract: Provided is a processing method for an operation system which performs operation processing in accordance with a detection amount detected by detection means and pulse output processing in which an operation result from the operation processing is transmitted as a pulse output, including: controlling transmission of the pulse output performed in the pulse output processing to make the transmission of the pulse output asynchronous with a timing of an end of the operation processing; and transmitting, by repeating the controlling, a pulse train having time-series continuity.
    Type: Application
    Filed: June 21, 2007
    Publication date: November 26, 2009
    Applicant: OVAL CORPORATION
    Inventors: Hirokazu Kitami, Shunji Saitoh, Hideki Shimada
  • Patent number: 7614297
    Abstract: A flowmeter having a vortex type detection means with a measurement tube provided in a flow passage that allows passage of a fluid therethrough, and having a vortex generator provided in the measurement tube that is opposed to a flow of the fluid. The flowmeter also includes a vortex detector detecting a change based on a Karman vortex generated by the vortex generator, a thermal type detection means having a temperature sensor and a heating temperature sensor protruding into the flow passage, and a flow rate converter controlling a power supply amount related to heating of the heating temperature sensor for attaining a fixed difference in temperature between the temperature sensor and the heating temperature sensor and calculating a flow rate of the fluid from the power amount. The flow rate converter also calculates the flow rate of the fluid from a detection value obtained by the vortex detector.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: November 10, 2009
    Assignee: Oval Corporation
    Inventor: Naoki Matsubara
  • Patent number: D601050
    Type: Grant
    Filed: April 20, 2009
    Date of Patent: September 29, 2009
    Assignee: Oval Corporation
    Inventors: Toshiyuki Satoh, Hirokazu Kitami
  • Patent number: D613195
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: April 6, 2010
    Assignee: Oval Corporation
    Inventor: Hiroyuki Kabaya
  • Patent number: D613196
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: April 6, 2010
    Assignee: Oval Corporation
    Inventor: Hiroyuki Kabaya
  • Patent number: D628106
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: November 30, 2010
    Assignee: Oval Corporation
    Inventor: Hiroyuki Kabaya