Patents by Inventor Surendra K. Chawla
Surendra K. Chawla 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).
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Patent number: 11890896Abstract: A preparation method of itaconate-butadiene bio-based engineering rubber belongs to the bio-based engineering rubber area. The bio-based engineering rubber of the present disclosure is formed through chemical crosslinking of copolymers, which are formed by polymerization of itaconate and butadiene emulsion. The number average molecular weight of the itaconate-butadiene copolymer is about 53000-1640000, and weight-average molecular weight is about 110000-2892000. Itaconate-butadiene copolymers are formed by polymerization of itaconate and butadiene emulsion, then and chemical crosslinking of the copolymer is performed to form bio-based engineering rubber using a traditional sulfur vulcanizing system. The bio-based engineering rubber has high molecular weights as well as lower glass-transition temperatures and can be vulcanized using the traditional sulfur vulcanizing system.Type: GrantFiled: June 2, 2016Date of Patent: February 6, 2024Assignees: BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY, THE GOODYEAR TIRE & RUBBER COMPANYInventors: Liqun Zhang, Xinxin Zhou, Runguo Wang, Weiwei Lei, He Qiao, Kuo-chih Hua, Joseph Kulig, Surendra K Chawla
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Patent number: 10806440Abstract: A hands-free mitral papillary muscle exposure device provides a clear view of the papillary muscles, including the pathology of the leaflets and chordae tendineae of a mitral valve apparatus, and comprises a retractor device comprises two arm members pivotally connected to one another which can be manually spread and adjusted about a pivot point to a desired arrangement relative to the mitral valve apparatus to prevent injury to surrounding muscle and tissue during an operative procedure. Each arm member includes a respective downwardly extending longitudinal projection to hold one of the anterior and posterior leaflets adjacent to said arm member when the retractor device is positioned relative to the mitral valve apparatus. The longitudinal projection on the anterior side of the retractor device is longer than the corresponding longitudinal projection on the posterior side to accommodate the longer size of the anterior leaflet in comparison with the posterior leaflet.Type: GrantFiled: August 12, 2019Date of Patent: October 20, 2020Inventor: Surendra K. Chawla
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Publication number: 20200060670Abstract: A hands-free mitral papillary muscle exposure device provides a clear view of the papillary muscles, including the pathology of the leaflets and chordae tendineae of a mitral valve apparatus, and comprises a retractor device comprises two arm members pivotally connected to one another which can be manually spread and adjusted about a pivot point to a desired arrangement relative to the mitral valve apparatus to prevent injury to surrounding muscle and tissue during an operative procedure. Each arm member includes a respective downwardly extending longitudinal projection to hold one of the anterior and posterior leaflets adjacent to said arm member when the retractor device is positioned relative to the mitral valve apparatus. The longitudinal projection on the anterior side of the retractor device is longer than the corresponding longitudinal projection on the posterior side to accommodate the longer size of the anterior leaflet in comparison with the posterior leaflet.Type: ApplicationFiled: August 12, 2019Publication date: February 27, 2020Inventor: Surendra K. Chawla
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Publication number: 20180250984Abstract: A preparation method of itaconate-butadiene bio-based engineering rubber belongs to the bio-based engineering rubber area. The bio-based engineering rubber of the present disclosure is formed through chemical crosslinking of copolymers, which are formed by polymerization of itaconate and butadiene emulsion. The number average molecular weight of the itaconate-butadiene copolymer is about 53000-1640000, and weight-average molecular weight is about 110000-2892000. Itaconate-butadiene copolymers are formed by polymerization of itaconate and butadiene emulsion, then and chemical crosslinking of the copolymer is performed to form bio-based engineering rubber using a traditional sulfur vulcanizing system. The bio-based engineering rubber of the present disclosure has high molecular weights as well as lower glass-transition temperatures and can be vulcanized using the traditional sulfur vulcanizing system.Type: ApplicationFiled: June 2, 2016Publication date: September 6, 2018Inventors: Liqun Zhang, Xinxin Zhou, Runguo Wang, Weiwei Lei, He Qiao, Kuo-chih Hua, Joseph Kulig, Surendra K. Chawla
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Patent number: 9486315Abstract: A valve repair instrument and method of repair for the mitral valve of the heart is disclosed. The valve repair instrument includes an elongated body having two ends. One of the ends being configured to maintain a muscle portion of a valve repair device in an expanded position for attachment to the papillary muscle, the other end being configured to maintain a leaflet portion of a valve repair device in an expanded position for attachment to a valve leaflet. The valve repair device is attached to the diseased valve by suturing the leaflet portion to the affected leaflet and suturing the muscle portion to the affected muscle.Type: GrantFiled: July 5, 2011Date of Patent: November 8, 2016Inventor: Surendra K. Chawla
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Patent number: 9248018Abstract: A valve repair device and method of repair for the mitral valve of the heart is disclosed. The valve repair device includes a leaflet portion, a muscle portion, and a plurality of chords connecting the leaflet portion to the muscle portion. The leaflet portion includes a plurality of partition members to assist the surgeon in sizing the repair device to the patient. A single partition member may form the leaflet portion. Alternatively, multiple partition members may form the leaflet portion. A partition member may include predetermined openings for the attachment of a suture.Type: GrantFiled: September 27, 2013Date of Patent: February 2, 2016Inventor: Surendra K. Chawla
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Publication number: 20150094800Abstract: A valve repair device and method of repair for the mitral valve of the heart is disclosed. The valve repair device includes a leaflet portion, a muscle portion, and a plurality of chords connecting the leaflet portion to the muscle portion. The leaflet portion includes a plurality of partition members to assist the surgeon in sizing the repair device to the patient. A single partition member may form the leaflet portion. Alternatively, multiple partition members may form the leaflet portion. A partition member may include predetermined openings for the attachment of a suture.Type: ApplicationFiled: September 27, 2013Publication date: April 2, 2015Inventor: Surendra K. Chawla
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Publication number: 20130013056Abstract: A valve repair instrument and method of repair for the mitral valve of the heart is disclosed. The valve repair instrument includes an elongated body having two ends. One of the ends being configured to maintain a muscle portion of a valve repair device in an expanded position for attachment to the papillary muscle, the other end being configured to maintain a leaflet portion of a valve repair device in an expanded position for attachment to a valve leaflet. The valve repair device is attached to the diseased valve by suturing the leaflet portion to the affected leaflet and suturing the muscle portion to the affected muscle.Type: ApplicationFiled: July 5, 2011Publication date: January 10, 2013Inventor: Surendra K. Chawla
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Patent number: 6997950Abstract: A valve repair device and method of repair for the mitral valve of the heart is disclosed. The valve repair device includes a leaflet portion, a muscle portion, and a plurality of chords connecting the leaflet portion to the muscle portion. The valve repair device is attached to the diseased valve by suturing the leaflet portion to the affected leaflet and suturing the muscle portion to the affected muscle. The leaflet portion and muscle portion are constructed of cloth made from expanded polytetraflouroethylene. The chords are sutures also constructed from expanded polytetraflouroethylene. The suture position for the muscle portion is determined by positioning the valve repair device adjacent to a normal marginal chord. The valve repair device may be employed to repair the anterior leaflet or posterior leaflet of the mitral valve.Type: GrantFiled: January 16, 2003Date of Patent: February 14, 2006Inventor: Surendra K. Chawla
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Patent number: 5323829Abstract: A pneumatic tire with carbon fiber cord reinforcement wherein the carbon fiber cords have a round cross sectional shape and a twist per inch (TPI) of 1.2 to 1.6 turns per inch (TPI) is provided. Preferably, the carbon fiber cords are coated with an RFL or epoxy/RFL adhesive. It is also preferred that carbon fiber cords having an S twist and carbon fiber cords having a Z twist be used in the same reinforcing plies in the tire. Especially preferred is the incorporation of carbon fiber cords in a folded belt.Type: GrantFiled: December 28, 1992Date of Patent: June 28, 1994Assignee: The Goodyear Tire & Rubber CompanyInventors: Joseph K. Hubbell, Perry W. Bell, David L. Bair, Surendra K. Chawla, Mahmoud Assaad, Warren L. Croyle, Joanne E. Shaw, Donald G. Vera
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Patent number: 5240566Abstract: A process for separating acetone, dichloromethane and trifluoroacetic acid from a mixture of acetone, dichloromethane, and a trifluoroacetic acid/acetone azeotropeby (1) fractionally distilling the mixture of acetone, dichloromethane, and the trifluoroacetic acid/acetone azeotrope;(2) fractionally distilling the mixture of the trifluoroacetic acid/acetone azeotrope and free acetone;(3) adding at least about 16 parts of water to the trifluoroacetic acid/acetone azeotrope per 100 parts by volume of the trifluoroacetic acid/acetone azeotrope;(4) fractionally distilling the mixture of free acetone and the water/trifluoroacetic acid azeotrope;(5) adding at least about 10 parts of sulfuric acid to the water/trifluoroacetic acid azeotrope per 100 parts by volume of the water/trifluoroacetic acid azeotrope;(6) fractionally distilling the mixture of trifluoroacetic acid and the water/sulfuric acid complex.Type: GrantFiled: December 7, 1992Date of Patent: August 31, 1993Assignee: The Goodyear Tire & Rubber CompanyInventors: Bruce R. Hahn, Thomas R. Maier, Surendra K. Chawla
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Patent number: 5225448Abstract: High molecular weight polyethyleneterephthalate resin is currently being used in vast quantities in manufacturing tire cord and in manufacturing trays for frozen foods which can be heated in either microwave or convection ovens. In some applications polyester resins having ultra-high molecular weights are required. For example, some techniques for producing polyester yarn by solution spinning demand ultra-high molecular weight polyester. Unfortunately, it becomes progressively more difficult and expensive to produce polyester resins having higher and higher molecular weights utilizing standard commercial polymerization techniques. This invention discloses a technique for preparing porous polyester beads which can be solid state polymerized very rapidly to ultra-high molecular weights.Type: GrantFiled: November 19, 1992Date of Patent: July 6, 1993Assignee: The Goodyear Tire & Rubber CompanyInventors: Thomas R. Maier, Surendra K. Chawla
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Patent number: 4682892Abstract: A nondestructive means of testing tires for subsurface defects by speckle-shearing interferometry. The tire is illuminated with a beam of coherent light. The light reflected from a surface of the tire is directed through a converging lens having one-half of one of its surfaces covered by a transparent plate having flat parallel sides such that a photographic media is exposed to a first pair of focused images of the tire displaced with respect to one another. The tire is then subjected to a stress, and a second pair of slightly displaced images is recorded on the same photographic media. The photographic media is developed to form a transparency, and then a first surface of the developed photographic media is illuminated with a collimated white light source. Interference fringes that are observed by viewing the opposite surface of the photographic media may then be analyzed.Type: GrantFiled: August 30, 1985Date of Patent: July 28, 1987Assignee: The Goodyear Tire & Rubber CompanyInventor: Surendra K. Chawla