Patents by Inventor Chidambaram Raghavan

Chidambaram Raghavan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5493954
    Abstract: A self-venting seal assembly for use in an ultrahigh-pressure pump is shown and described. In a preferred embodiment, a low-pressure seal is used to energize a high-pressure seal, the low-pressure seal having a "u" shaped cross-section, thereby creating a groove in a first end of the low-pressure seal. When the first end of the seal is exposed to pressurized fluid, it expands outwardly thereby substantially preventing the leakage of fluid past it. To the extent that any pressurized fluid does leak past the seal, which would act against a second end of the seal when the pressure on the opposite side of the seal drops, the seal compresses inwardly, thereby allowing the pressurized fluid to flow back past the seal.In a preferred embodiment, the high-pressure seal comprises a sleeve seal having an annular opening through which the plunger reciprocates, the sleeve seal being supported by a backup ring, the backup ring also having an annular opening through which the plunger passes.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: February 27, 1996
    Assignee: Flow International Corporation
    Inventors: Kraig Kostohris, Olivier L. Tremoulet, Jr., Thomas Sizemore, Larry Pearson, Chidambaram Raghavan
  • Patent number: 5417607
    Abstract: A nozzle for producing an ultrahigh-pressure fluid fan jet is shown and described. In a preferred embodiment, the nozzle has an inner surface defined by a conical bore extending from a first end to a second end, thereby creating an entrance orifice and an exit orifice in the first and second ends, respectively. A wedge-shaped notch extends inward from the second end towards the first end to a sufficient depth such that the shape of the exit orifice is defined by the intersection of the conical bore and the wedge-shaped notch. As pressurized fluid passes through the nozzle and out the exit orifice, the shape of the exit orifice causes the pressurized fluid to exit in the form of a fan jet having a substantially oval cross-section. This fan jet may be swept across a surface to be cleaned thereby selectively removing a layer of material from an underlying surface evenly and completely, without damaging the underlying surface. The fan jet may also be used to cut a fibrous or hard material.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: May 23, 1995
    Assignee: Flow International Corporation
    Inventors: Chidambaram Raghavan, Edmund Y. Ting, Olivier L. Tremoulet, Jr., Anton H. Buchberger
  • Patent number: 5381631
    Abstract: A method and apparatus for cutting metal casings with an ultrahigh-pressure abrasive fluid jet is shown and described. Examples of such casings include piles and conductors of offshore oil production platforms. In accordance with a preferred embodiment of the present invention illustrated herein, the apparatus is lowered inside the casing to be cut to a desired depth where it is secured to an inner surface of the casing. An ultrahigh-pressure stream of fluid is forced through a nozzle provided in a jet manifold of the apparatus to produce an ultrahigh-pressure fluid jet, into which a volume of abrasives is entrained, thereby generating an abrasive fluid jet. A drive mechanism is provided to rotate the abrasive fluid jet in a substantially horizontal plane to produce a circumferential cut in the casing. The abrasive fluid jet may also be moved in a vertical plane if necessary to complete the cut, for example if the initial cut is in the form of a helix.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: January 17, 1995
    Assignee: Flow International Corporation
    Inventors: Chidambaram Raghavan, John Olsen, Curtis L. Anderson, Alton J. LaLande
  • Patent number: 5380068
    Abstract: A method and system for cutting kerfs in rock is shown and described. In one embodiment, a single fan jet is mounted in ultrahigh-pressure tubing. In an alternative embodiment, a manifold in which two fan jets are mounted is coupled to a manifold in which two round jets are mounted, such that the twin fan jets are directed so as to cover the entire width of the kerf and the round jets are directed towards the edges of the kerf to cut out a well defined kerf. In another alternative embodiment, an angled fan nozzle is mounted in ultrahigh-pressure tubing and combined in a system with another angled fan nozzle mounted in ultrahigh-pressure tubing such that the angled fan jets may be directed at opposite walls of a kerf to carve out a well defined kerf of a desired depth.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: January 10, 1995
    Assignee: Flow International Corporation
    Inventor: Chidambaram Raghavan
  • Patent number: 5380159
    Abstract: A pressure compensation device for use in a high-pressure direct driven pump to control the output pressure of the pump is shown and described. In a preferred embodiment, the high-pressure pump has a valve assembly that selectively allows fluid pressurized by a reciprocating plunger to pass from a pressurization chamber to an outlet chamber from which the pressurized fluid is collected for use. A pressure compensation device has a lever which balances a control force against a force generated by the high-pressure fluid in the outlet chamber. When the outlet pressure exceeds a selected level, the pressure compensation device acts to prevent the further pressurization of fluid by causing the fluid to flow back out of the pressurization chamber via the same passageway(s) through which the fluid was originally introduced into the system.
    Type: Grant
    Filed: June 16, 1994
    Date of Patent: January 10, 1995
    Assignee: Flow International Corporation
    Inventors: John H. Olsen, Olivier L. Tremoulet, Jr., Chidambaram Raghavan
  • Patent number: 5337561
    Abstract: An improvement in a multiple intensifier system having two intensifier units with reciprocating piston assemblies to supply very high pressure water. When one of the piston assemblies travels faster than the other, so that these reached an end stroke position at the same time, there can be an abrupt pressure drop. To alleviate this, a first embodiment isolates the compensator control lines of the pumps of the two intensifier units so as to maximize volumetric flow rates during such pressure drops to give the slower moving piston assembly a boost at the beginning of its subsequent stroke. Another embodiment provides an accumulator in the fluid control line for the compensators, and a further embodiment provides a pressure reference supply pump to alleviate pressure variations in the fluid control line.
    Type: Grant
    Filed: November 17, 1992
    Date of Patent: August 16, 1994
    Assignee: Flow International Corporation
    Inventors: Chidambaram Raghavan, Kraig T. Kostohris, Adrain C. O. Hawes
  • Patent number: 5316745
    Abstract: An ultra high pressure sterilizing apparatus and method comprising a cylinder and plunger assembly that operates on a power compression stroke where material to be sterilized is alternately pressurized and depressurized in the cylinder chamber. The cylinder and plunger assembly also moves on a discharge and intake stroke where material that has been sterilized through pressurizing and depressurizing cycles is removed from the chamber through selectively operable valve means, and a fresh quantity of material to be sterilized is moved into the cylinder chamber for another set of pressurizing and depressurizing cycles.
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: May 31, 1994
    Assignee: Flow International Corporation
    Inventors: Edmund Y. Ting, Chidambaram Raghavan
  • Patent number: 5228623
    Abstract: An apparatus to remove rubber from airplane tires from an airport runway surface. there is a manifold arm which rotates at as high as two thousand five hundred rpms over the runway surface, with a plurality of water jets being discharged downwardly at a relatively high pressure (e.g. thirty five thousand P.S.I.) against the runway surface. Even though the water pressure is at a level several times higher than that at which damage to the runway surface can occur, at the relatively high linear speed of the water jets (e.g. ninety to one hundred eighty miles per hour), there is no noticeable damage to the runway surface, but yet there is quite effective removal of the accumulated rubber. Also disclosed is a particular shaft and seal assembly which is capable of operating at relatively high rotational speeds and delivering the high pressure to the manifold arm.
    Type: Grant
    Filed: January 3, 1992
    Date of Patent: July 20, 1993
    Inventors: Chidambaram Raghavan, John H. Olsen
  • Patent number: 5226799
    Abstract: A low wear poppet valve in a high pressure reciprocating pump. Relative movement of the mating surfaces due to compressive distortion is eliminated. There is a valve seat having a flow passage and an upper mating surface, and a poppet element which sealingly abuts this. The flow passage is in communication with a low pressure zone, and the outer surfaces of the seat and element are in communication with a high pressure zone. The poppet element has a recess in its mating surface surrounded by a wall portion, and the low pressure zone is communicated from the flow passage into the interior of the recess. This enables the wall portion of the element to be displaced inwardly and outwardly in concert with the wall portion of the seat by the cyclic pressure differential which is generated between the zones by the operation of the pump. This eliminates relative movement between these parts which would otherwise cause fretting wear of their mating surfaces.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: July 13, 1993
    Assignee: Flow International Corporation
    Inventors: Chidambaram Raghavan, Olivier L. Tremoulet, Jr., Edmund Y. Ting
  • Patent number: 5078161
    Abstract: An apparatus to remove rubber from airplane tires from an airport runway surface. There is a manifold arm which rotates at as high as two thousand five hundred rpms over the runway surface, with a plurality of water jets being discharged downwardly at a relatively high pressure (e.g. thirty five thousand P.S.I.) against the runway surface. Even though the water pressure as at a level several times higher than that at which damage to the runway surface can occur, at the relatively high linear speed of the water jets (e.g. ninety to one hundred eighty miles per hour), there is no noticeable damage to the runway surface, but yet there is quite effective removal of the accumulated rubber. Also disclosed is a particular shaft and seal assembly which is capable of operating at relatively high rotational speeds and delivering the high pressure to the manifold arm.
    Type: Grant
    Filed: May 31, 1989
    Date of Patent: January 7, 1992
    Assignee: Flow International Corporation
    Inventors: Chidambaram Raghavan, John H. Olsen
  • Patent number: 5014423
    Abstract: A high pressure hose assembly is manufactured wherein the nipple of the hose fitting includes an O-ring receiving groove formed about its periphery. The O-ring and groove are dimensioned so that the crimping of the fitting's outer sleeve causes the linear of the high pressure hose to flow into the groove, comprising the O-ring into the groove, and sealing against the O-ring within the groove.
    Type: Grant
    Filed: March 2, 1989
    Date of Patent: May 14, 1991
    Assignee: Flow Systems, Inc.
    Inventor: Chidambaram Raghavan
  • Patent number: 4858967
    Abstract: A high pressure hose fitting, and method for sealing the hose to a fitting, is disclosed for use with hoses of the type including a linear disposed about an axially extending passageway, and a reinforcement layer circumventing the liner. The liner is preferably pulled slightly beyond the edge of the reinforcement layer to form a protruding edge region. An end fitting, having a flange with a liner-receiving groove, is inserted into the passageway until the protruding edge of the liner contacts the end wall of the groove, and the flange abuts the reinforcement layer. A swagable collar circumventing the foregoing components is swaged radially inwardly to clamp the liner on its outside diameter.
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: August 22, 1989
    Assignee: Flow Systems, Inc.
    Inventors: Olivier L. Tremoulet, Jr., Chidambaram Raghavan
  • Patent number: 4649963
    Abstract: An ultra-high pressure hose assembly capable of withstanding sustained internal fluid pressures exceeding 60,000 psi is disclosed herein and consists essentially of an innermost tubular core, a plurality of successive tubular layers and an outer containment sleeve. The innermost tubular core and containment sleeve are designed to add substantially no structural integrity to the overall assembly but rather function only as a fluid barrier and containment structure for the tubular layers respectively. The outer tubular layers serve as structural members of the overall assembly and respectively consist of individual bands which are alternately helically wound around and directly against the layers immediately below them at predetermined helix angles. Each band in turn consists of a number of separate steel wires which have opposing flat sides and which are positioned in unconnected edge to edge relationship to one another so as to form the band.
    Type: Grant
    Filed: January 31, 1986
    Date of Patent: March 17, 1987
    Assignee: Flow Industries, Inc.
    Inventors: Chidambaram Raghavan, John H. Olsen