Reverse Curve Surface Patents (Class 416/242)
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Patent number: 4780058Abstract: A fluid foil for use in a marine propeller having an upper surface with a uniform, continuous convex shape commencing at the leading edge and terminating at the trailing edge of the foil section and a lower foil face having a convex shape extending from the said leading edge to the foil mid/chord position and having a concave shape extending from the said mid-chord position to the said trailing edge. An effective pitch line extending from the foil leading edge to the foil trailing edge is intersected tangentially by the concave shape of the lower foil face.Type: GrantFiled: December 3, 1986Date of Patent: October 25, 1988Assignee: Marine Systems Research Inc.Inventor: Adrian Phillips
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Patent number: 4775297Abstract: The vane of the impeller in a high-speed or mixed-flow centrifugal pump for the conveying of liquids which contain high or low concentrations of strands or strips of vegetable, plastic or other material has a convex inlet edge whose curvature increases gradually in a direction radially outwardly from the axis of rotation at such a rate that the resultant of the centrifugal force and the resistance encountered by a strip or strand at a particular point of the inlet edge is invariably tangential to the respective point of the inlet edge. This ensures that the strips or strands do not overlie and circulate with the inlet edge but are entrained by the resultant force to become separated from the vane. The stagnation paint of the vane in a region which is remote from the axis of rotation is disposed at the suction side of the vane; this also contributes to prevention of accumulation of strips or strands along the inlet edge.Type: GrantFiled: March 10, 1987Date of Patent: October 4, 1988Assignee: Klein, Schanzlin & Becker AktiengesellschaftInventor: Jan Bernauer
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Patent number: 4773825Abstract: The invention relates to improvements to air propellers in so far as the profile of their blades is concerned. The law of evolution of the curvatures of the extrados 2 is the following: the curvature, maximum at the leading edge A, increases first of all rapidly to reach a value of about 4 at the point B at about 4% of the length of the chord, and then decreases regularly to reach a substantially zero value at the trailing edge F. The law of evolution of the curvatures of intrados 3 is the following: the curvature, maximum at the leading edge A, decreases first of all rapidly to reach a value of about 8 at a point D at about 3.5% of the length of the chord, then decreases less rapidly to reach a zero value at a point E situated between 10% and 60% of the length of the chord, decreases further to a slightly negative value and then remains practically constant as far as the trailing edge F.Type: GrantFiled: November 17, 1986Date of Patent: September 27, 1988Assignee: Office National D'Etudes et de Recherche Aerospatiales (ONERA)Inventors: Anne M. Rodde, Jean J. Thibert
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Patent number: 4744728Abstract: A family of airfoil cross sections, termed SC21xx, for use in a helicopter blade is disclosed. The airfoil (36) achieves maximum lift performance equivalent to prior art airfoil configurations without incurring increased aerodynamic drag at high velocities. The airfoil (36) was developed by thickening and drooping the leading edge region (38) of the prior art airfoil (30) improving lift in the leading edge region (38) and delaying the formation of sonic shock waves at high velocities.Type: GrantFiled: September 3, 1986Date of Patent: May 17, 1988Assignee: United Technologies CorporationInventors: David A. Lednicer, Stephen J. Owen
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Patent number: 4741670Abstract: The invention relates to a boat propeller unit with double, counter-rotating propellers. The forward propeller is designed to function without cavitation, while the after-propeller is optimally cavitating by being made cupped and with a blade width of between 60% and 75% of the blade width of the forward propeller.Type: GrantFiled: September 12, 1986Date of Patent: May 3, 1988Assignee: AB Volvo PentaInventor: Lennart H. Brandt
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Patent number: 4737077Abstract: The blade has an axis (.GAMMA.) which is the locus of the thrust centers (C) of its cross-sections parallel to its foot (13) which has a connecting point (I) between an abyssal arc (.gamma..sub.1) whose concavity faces toward the leading edge (11) and a summit arc (.gamma..sub.2) whose concavity faces toward the trailing edge (12) of the blade.Type: GrantFiled: September 11, 1987Date of Patent: April 12, 1988Assignee: Aciers et Outillage PeugeotInventor: Jean-Claude Vera
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Patent number: 4700579Abstract: A flow meter mounted in a flow delivery line and having a meter housing with a fluid opening and an electric counter. A turbine rotor supported on a turbine shaft is disposed in the fluid opening, the turbine having plural turbine blades with ferrous slugs embedded therein, the electric counter responding thereto for fluid delivery indication. Each turbine blade is tapered from front to rear into a feathered trailing edge and has a top concave surface along its length and a bottom convex surface. A pair of shaft supports, having fluid ports for washing about the turbine shaft, are provided to support the turbine rotor.Type: GrantFiled: February 5, 1986Date of Patent: October 20, 1987Assignee: Great Plains Industries, Inc.Inventor: Robert E. Hall
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Patent number: 4696621Abstract: A gas turbine engine nozzle guide vane has "barrelled" shape, producing an "hourglass" shaped passage between adjacent vanes. These shapes promote radial pressure gradients which reduce secondary flaws in the motive gas passages.Type: GrantFiled: April 29, 1986Date of Patent: September 29, 1987Assignee: Rolls-RoyceInventors: Martin Hamblett, Duncan J. Livsey
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Patent number: 4682935Abstract: The invention comprises a blade for a gas turbine engine including an airfoil portion having a non-linear stacking axis which is effective for generating a compressive component of bending stress due to centrifugal force acting on the blade. The compressive component of bending stress is provided in a life-limiting section of the blade, which, for example, includes trailing and leading edges of the blade. Inasmuch as the stacking axis, which represents the locus of centers of gravity of transverse sections of an airfoil portion of the blade, is non-linear, an increased amount of a compressive component of bending stress can be generated at a life-limiting section between root and tip sections of the blade without substantially increasing bending stress at the root of the blade.Type: GrantFiled: December 12, 1983Date of Patent: July 28, 1987Assignee: General Electric CompanyInventor: Jack R. Martin
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Patent number: 4585395Abstract: The invention comprises a blade for a gas turbine engine including an airfoil portion having a non-linear stacking axis intersecting a reference radial axis that is effective for generating a compressive component of bending stress due to centrifugal force acting on the blade. The compressive component of bending stress is provided in a life-limiting section of the blade, which, for example, includes trailing and leading edges of the blade. Inasmuch as the stacking axis, which represents the locus of centers of gravity of transverse sections of an airfoil portion of the blade, is non-linear, an increased amount of a compressive, component of bending stress can be generated at a life-limiting section between a root and tip of the blade without substantially increasing bending stress at the root of the blade due to the non-linear stacking.Type: GrantFiled: December 12, 1983Date of Patent: April 29, 1986Assignee: General Electric CompanyInventors: John G. Nourse, John J. Bourneuf, David R. Abbott
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Patent number: 4569633Abstract: An airfoil shaped cross section 36 for the rotor blade 14 is disclosed. Various construction details which improve the aerodynamic and drag performance of the airfoil section are developed. The upper surface 38 and the lower surface 42 are contoured by a thickness distribution and a camber distribution such that the bend of the surfaces is constant or changes at a constant rate over certain regions of the airfoil to avoid the formation of strong, normal shock waves at local Mach numbers less than 1.2 during normal, level flight conditions at standard temperature and pressure.Type: GrantFiled: April 18, 1983Date of Patent: February 11, 1986Assignee: United Technologies CorporationInventor: Robert J. Flemming, Jr.
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Patent number: 4564337Abstract: An aircraft propeller blade comprising an inner section which extends from the propeller hub toward the blade tip, a middle section adjacent to said inner section, and an outer section which extends from adjacent to said middle section to the blade tip; where the largest camber in the inner section decreases linearly over the blade length from adjacent to the propeller hub toward the blade tip, and the greatest camber height location shifts linearly over the blade length toward the blade tip; the largest camber in the middle section increases linearly over the blade length toward the blade tip, and the greatest camber height location shifts approximately linearly from adjacent to the inner section toward the blade tip; and the camber in the outer section decreases elliptically over the blade length toward the blade tip, and the greatest camber height location remains constant from adjacent to the middle section to the blade tip.Type: GrantFiled: October 11, 1983Date of Patent: January 14, 1986Assignee: Dornier Gesellschaft mit besehrankter HaftungInventors: Herbert Zimmer, Ingo Dathe, Reinhard Hoffmann, Petr Hora, Franz X. Wortmann
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Patent number: 4557666Abstract: A fixed pitch wind turbine rotor (18) is teeter mounted (76, 78, 80) onto a low speed input shaft (44) which is connected to the input (58) of a step-up transmission (46). The output (48) of the transmission (46) is connected to a rotary pole amplitude modulated induction machine (42) which is operable as a generator at a plurality of discreet speeds of rotation and is also operable as a startup motor for the rotor. A switch (45) responsive to the rotational speed of the wind turbine rotor switches the generator from one speed of operation to the other. The rotor hub (72) and the inner body portions (71) of two blades (68, 70), which extend radially outwardly in opposite directions from the hub (72), are constructed from steel. The outer end portions (73) of the blade (68, 70) are constructed from a lighter material, such as wood, and are both thinner and narrower than the remainder of the rotor.Type: GrantFiled: September 29, 1983Date of Patent: December 10, 1985Assignee: The Boeing CompanyInventors: Joseph M. Baskin, Gary E. Miller, Wayne Wiesner
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Patent number: 4552511Abstract: An improved propeller blade configuration that permits a relatively strong configuration without reducing the cavitation thickness or efficiency of the blade. This is achieved by providing a planar section on the front face of the blade that merges into a recessed cup shaped portion and by having the rearwardmost axial portion of the rear face lie in an axial direction contiguous to the point of merger.Type: GrantFiled: November 28, 1983Date of Patent: November 12, 1985Assignee: Sanshin Kogyo Kabushiki KaishaInventor: Yukio Sumigawa
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Patent number: 4543041Abstract: An impeller for a centrifugal impeller comprising a disc portion, a coaxial hub portion having a longitudinal through-bore by which the impeller is mounted on a rotatable shaft, and a plurality of blades in any one of several forms. The tip of each blade is curved in a direction opposite to the rotation of the impeller more than the rest of the blade. The radius of the tip curve decreases uniformly toward the radially outer end of the blade. This tip treatment produces improved isentropic efficiency.Type: GrantFiled: January 10, 1985Date of Patent: September 24, 1985Assignee: Holset Engineering Company LimitedInventors: Pierre B. French, Paul J. Langdon
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Patent number: 4531890Abstract: Centrifugal fans are provided comprising impellers having backward inclined blades that are cambered radially inward and that are inclined at an angle less than about 40.degree. relative to the tangential direction of the midpoint of a chord connecting the leading and trailing edges of each blade.Type: GrantFiled: January 24, 1983Date of Patent: July 30, 1985Inventor: Walter S. Stokes
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Patent number: 4479721Abstract: An agitator for grape mash comprising a rotary shaft and blade-shaped stirring wings having at least one first section inclined at an angle relative to the sense of rotation is characterized in that the said first section (19, 23) ends--viewed in at least one sense of rotation--in a second wing section (20, 21, 25, 26, 50, 51) inclined in the same direction but at an angle smaller than the angle of inclination of the said first section.Type: GrantFiled: November 13, 1981Date of Patent: October 30, 1984Inventor: Herbert Rieger
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Patent number: 4459083Abstract: This invention is an airfoil which has particular application to the blade or blades of rotor aircraft and aircraft propellers. The airfoil thickness distribution, camber and leading edge radius is shaped to locate the airfoil crest at a more aft position along the chord, and to increase the freestream Mach number at which sonic flow is attained at the airfoil crest. The upper surface of the airfoil has a general reduction in the surface slope back to the maximum ordinate which is about 40 percent of the airfoil chord. The reduced slope causes a reduction in velocity at the airfoil crest at lift coefficients from zero to the maximum lift coefficient. The leading edge radius is adjusted or shaped so that the maximum local Mach number at 1.25 percent chord and at the designed maximum lift coefficient is limited to about 0.48 when the Mach number normal to the leading edge is approximately 0.20.Type: GrantFiled: March 6, 1979Date of Patent: July 10, 1984Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventor: Gene J. Bingham
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Patent number: 4416434Abstract: The present invention relates to a blade section for rotating wings of an aircraft comprising, between the leading edge and the trailing edge, a convex lower surface and an upper surface which is convex over the greater part of its length, but concave near the trailing edge. According to the invention, the upper surface of the section comprises a region of small extent, close to the leading edge but not contiguous thereto, in which the curvature is substantially constant. The invention is applicable to the improvement of the performances in maneuvering flight, while hovering and in advance flight of the aircraft.Type: GrantFiled: August 17, 1981Date of Patent: November 22, 1983Assignees: Societe Nationale Industrielle Aerospatiale, Office National d'Etudes et de Recherches AerospatialesInventors: Jean-Jacques Thibert, Anne-Marie Rodde, Jean-Marc E. Pouradier
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Patent number: 4412664Abstract: This invention is an airfoil which has particular application to the blade or blades of rotor aircraft such as helicopters and aircraft propellers. The airfoil thickness distribution and camber are shaped to maintain a near zero pitching moment coefficient over a wide range of lift coefficients and provide a zero pitching moment coefficient at section Mach numbers near 0.80 and to increase the drag divergence Mach number resulting in superior aircraft performance.Type: GrantFiled: June 25, 1982Date of Patent: November 1, 1983Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventor: Kevin W. Noonan
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Patent number: 4401410Abstract: A blade of the fan wheel of a diagonal-flow fan, which blade should ideally have a shape of a twisted double-curvature or undevelopable surface, is formed from a portion of a combination of a cylindrical plate and a planar plate tangent to the cylindrical plate or of a combination of a pair of mutually circumscribing cylindrical surfaces, which portion constitutes a developable surface. To realize the formation of a blade from the developable surface, lines of intersection between combined cylinder and planar plates or combined cylinders and a number of coaxial imaginary conical surfaces representing streamlines in the fan wheel are used as a basis for design.Type: GrantFiled: December 8, 1980Date of Patent: August 30, 1983Assignee: Kawasaki Jukogyo Kabushiki KaishaInventor: Yoshiyasu Nishikawa
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Patent number: 4334826Abstract: Several forms of surface impeller for aeration of liquids are disclosed. All of the forms are of the shrouded or closed turbine type. In one form, the impeller has a large-diameter flat steel horizontal upper disc adapted to be secured to the lower end of a vertically disposed rotatable drive shaft. Secured, as by welding, to the undersurface of the upper disc are a plurality, such as six or eight or other number, of vertical blades at uniform spacing. Each blade is curved in a retreating or backward direction relative to the direction of rotation of the impeller. Each blade has a long or deep vertical inner edge located forward of the center axis of rotation. The lower edge of each blade is inclined upwardly toward a relatively short or shallow vertical outer edge located near the outer periphery of the upper disc. The horizontal innermost portion of the otherwise inclined bottom edge of each blade is welded to a small lower tie plate.Type: GrantFiled: February 4, 1980Date of Patent: June 15, 1982Inventors: John R. Connolly, David E. Gibson, Edward L. Heimark, Jerome B. Quinn, Richard E. Speechley, Richard L. Winter
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Patent number: 4285636Abstract: Wind power turbines are largely divided into vertical axis type wind power turbines and propeller type (horizontal axis type) wind power turbines. The present invention discloses a vertical axis type wind power turbine. The airfoil of blades in this vertical axis type wind power turbine is formed in such manner that, denoting a proper position on the airfoil chord line as a camber reversing position, a camber having a downward convex curvature is given between said position and a leading edge and a camber having an upward convex curvature is given between said position and a trailing edge so as to be a mean line and a rational thickness distribution is given to this mean line. This vertical axis type wind power turbine is formed by keeping the spanwise direction of the above mentioned blade parallel with a vertical rotary axis and fitting a plurality of blades at regular intervals at a distance to the vertical rotary axis through respective supporting arms.Type: GrantFiled: February 17, 1978Date of Patent: August 25, 1981Assignee: Gakko Hojin Tokai UniversityInventors: Yoshio Kato, Kazuichi Seki, Yoshio Shimizu
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Patent number: 4284388Abstract: The invention finds application in the manufacture of working blades of a length exceeding that of the blades known so far, without infringing the limitations issuing from flow considerations and strength of the rotor. The blade comprises two different sheets deliminated by a suitably selected intermediary cross section of the blade. Each of the sheets is formed according to a different law dictated by strength and flow considerations. Beginning from the cross-section which delimits the sheets, the sheets are twisted in opposite directions.Type: GrantFiled: February 1, 1979Date of Patent: August 18, 1981Assignee: Polska Akademia Nauk, Instytut Maszyn PrzeplywowychInventor: Robert Szewalski
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Patent number: 4274810Abstract: A blade of the fan wheel of a diagonal-flow fan, which blade should ideally have a shape of a twisted double-curvature or undevelopable surface, is formed from a portion of a combination of a cylindrical plate and a planar plate tangent to the cylindrical plate or of a combination of a pair of mutually circumscribing cylindrical surfaces, which portion constitutes a developable surface. To realize the formation of a blade from the developable surface, lines of intersection between combined cylinder and planar plates or combined cylinders and a number of coaxial imaginary conical surfaces representing streamlines in the fan wheel are used as a basis for design.Type: GrantFiled: June 23, 1978Date of Patent: June 23, 1981Assignee: Kawasaki Jukogyo Kabushiki KaishaInventor: Yoshiyasu Nishikawa
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Patent number: 4264279Abstract: This invention relates to a fixed geometry self starting wind turbine having a blade rotatable about a vertical axis. The blade is of a wide streamlined cambered airfoil shape and has a forward portion that includes a well rounded leading edge and thickness distribution that is conducive to high lift to drag ratios and having a high drag characteristic in reversed flows. The concave curvature of this camber line of said airfoil is directed to the rotational axis. The wide blade in combination with the well rounded leading edge, camber and airfoil thickness gives the turbine improved self-starting characteristics and causes the turbine to have improved acceleration characteristics through the intermediate speed range and up to full operating speed.Type: GrantFiled: May 12, 1978Date of Patent: April 28, 1981Inventor: Viggo G. Dereng
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Patent number: 4248572Abstract: A cambered helicopter blade having a swept and tapered tip, and having linear twist throughout the outer 70 percent of the blade span and nonlinear twist inboard thereof.Type: GrantFiled: December 11, 1978Date of Patent: February 3, 1981Assignee: United Technologies CorporationInventor: Evan A. Fradenburgh
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Patent number: 4197057Abstract: The fan assembly for a motor vehicle includes a plurality of radially extending blades each having a first rearwardly facing concave curvature extending along the entire length of the blade adjacent the leading edge and a forwardly facing concave curvature at the outer end of the blade adjacent the trailing edge to increase the cooling efficiency of the fan and decrease the noise produced during operation.Type: GrantFiled: April 17, 1978Date of Patent: April 8, 1980Assignee: Aisin Seiki Kabushiki KaishaInventor: Masaharu Hayashi
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Patent number: 4174924Abstract: A sheet metal fan exhibiting special utility as a radiator fan for an internal combustion engine. A spider carries the blades on its arms, the arms each having a radially extending stiffening rib in opposed relation to a complementary rib in its blade to thereby form a tube where the stiffening ribs are radially coextensive. The stiffening rib on each blade intersects a continuous, blade stiffening channel.Type: GrantFiled: August 16, 1977Date of Patent: November 20, 1979Assignee: Wallace Murray CorporationInventor: Charles L. Smithson, Jr.
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Patent number: 4172691Abstract: A sheet metal fan exhibiting special utility as a radiator fan for an internal combustion engine. A spider carries the blades on its arms, the arms each having a radially extending stiffening rib in opposed relation to a complementary rib in its blade to thereby form a tube where the stiffening ribs are radially coextensive. The stiffening rib on each blade intersects a continuous, blade stiffening channel.Type: GrantFiled: August 16, 1977Date of Patent: October 30, 1979Assignee: Wallace Murray CorporationInventors: Everad A. Comstock, Charles L. Smithson, Jr.
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Patent number: 4073601Abstract: A marine propeller with unique blade geometry resistant to cavitation and ventilation at high speed operation. The face of the blade has a special convexly curved portion extending from the leading blade edge to a transition zone along the blade chord length toward the blade trailing edge, and a special concavely curved portion from this transition zone to the trailing blade edge, both defined herein.Type: GrantFiled: June 14, 1976Date of Patent: February 14, 1978Assignee: Dana CorporationInventor: Robert F. Kress
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Patent number: 4002414Abstract: The present device is a rotor having a plurality of rotor chambers formed integral therewith. Each chamber has an inlet opening into a main section, whose sidewalls are substantially parallel, and further has a nozzle section whose sidewalls deviate at an angle from the main section sidewalls to create a sharp cross-sectional constriction and which nozzle section ends in an outlet opening. The present rotor is used as the single rotor of a turbine engine which has means to initiate a shock wave at the opening of the main section of each rotor chamber. The rotor chamber is formed to direct the shock wave uninhibited toward said outlet opening but said shock wave is reflected from said sharp cross-sectional constriction toward said inlet opening thereby compressing the gases in said chamber to a high pressure. In each chamber when said high pressure gases expand through said nozzle section the ensuing reaction drives said rotor.Type: GrantFiled: April 25, 1974Date of Patent: January 11, 1977Inventors: Richard R. Coleman, Jr., Helmut E. Weber
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Patent number: 3998567Abstract: A pressure exchanger cell ring comprising a rotor which, viewed in cross-section, possesses cell walls of at least double curvature, each of the cell walls being secured at its ends to the hub and shroud, respectively, of the rotor. Each cell wall is shaped to have protruding portions or lobes, each curving to either side of a radius extending through one of both attachment locations of the cell wall. The sector angle enclosed between the two radii extending from the center of the rotor through each attachment location of a cell wall does not exceed 4.degree., and the sector angle bounding the mean camber line of the cell wall does not exceed 7.degree..Type: GrantFiled: June 26, 1975Date of Patent: December 21, 1976Assignee: BBC Brown Boveri & Company LimitedInventor: Reinhard Fried
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Patent number: 3964840Abstract: A blade for a centrifugal pump impeller comprises a pressure end or blade tip lying in a first radius about the rotational axis joined to a suction end opposite the pressure end and lying in a second radius by a pumping surface having a concave portion adjacent the pressure end running into a convex portion adjacent the pressure end, the two radii being angularly spaced with the second radius leading in the direction of intended rotation.Type: GrantFiled: December 30, 1974Date of Patent: June 22, 1976Inventor: Eduard Kamelmacher