Patents by Inventor David J. Jennings
David J. Jennings 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: 10650864Abstract: Described are electronic hard disk drives that are made to include: a base; a cover; interior components such as a stack of magnetic recording disks, reading and recording heads, electronics to read and record and to transfer data to and from an external electronic device; and a cover support at the interior of the device to inhibit movement of the cover.Type: GrantFiled: November 30, 2018Date of Patent: May 12, 2020Assignee: SEAGATE TECHNOLOGY LLCInventors: Gordon A. Harwood, Hany Michael Gross, David J. Jennings, Stanislaw Dobosz
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Patent number: 6741420Abstract: A hydrodynamic spindle motor including an internally disposed heating element in a stationary spindle portion having a spindle hub rotatably coupled thereto. The hydrodynamic spindle motor has particular application for supporting discs for co-rotation for a disc drive. The heating element is activated to control viscosity of a hydrodynamic fluid of a hydrodynamic bearing rotationally supporting the spindle hub relative to the stationary spindle. Operation of the heating element reduces viscosity of the hydrodynamic fluid to reduce motor power requirements and improve “up-to-speed” time.Type: GrantFiled: June 28, 2001Date of Patent: May 25, 2004Assignee: Seagate Technology LLCInventors: David J. Jennings, John Elsing
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Patent number: 6525440Abstract: This invention deals with compensating for thermal changes such that the spindle motor bearing preload remains as constant as possible throughout the disc drive operational temperature range. This is achieved by selecting a combination of materials with a composite thermal expansion that offsets the differential expansion of the steel bearing supports and the ceramic balls. The change in materials and configuration can be either that of the shaft, the hub, the support members, or any combination thereof.Type: GrantFiled: April 19, 2000Date of Patent: February 25, 2003Assignee: Seagate Technology LLCInventors: John W. Elsing, David J. Jennings, Martin F. Byl, Jeffery A. LeBlanc, Robert M. Pelstring
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Publication number: 20020051312Abstract: A hydrodynamic spindle motor including an internally disposed heating element in a stationary spindle portion having a spindle hub rotatably coupled thereto. The hydrodynamic spindle motor has particular application for supporting discs for co-rotation for a disc drive. The heating element is activated to control viscosity of a hydrodynamic fluid of a hydrodynamic bearing rotationally supporting the spindle hub relative to the stationary spindle. Operation of the heating element reduces viscosity of the hydrodynamic fluid to reduce motor power requirements and improve “up-to-speed” time.Type: ApplicationFiled: June 28, 2001Publication date: May 2, 2002Inventors: David J. Jennings, John Elsing
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Patent number: 5930075Abstract: A disc drive data storage system according to the present invention includes a housing, a central axis, a stationary member which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member which is rotatable about the central axis with respect to the stationary member. A stator is fixed with respect to the housing. A rotor is supported by the rotatable member and is magnetically coupled to the stator. At least one data storage disc is attached to and is coaxial with the rotatable member. A hydro bearing interconnects the stationary member and the rotatable member and includes a blend of base fluids. The base fluids in the blend are selected such that one of the base fluids has a viscosity that is greater than a desired viscosity selected for the disc drive, another of the base fluids has a viscosity that is less than the desired viscosity and the blend of base fluids has a viscosity that is within a selected range of the desired viscosity.Type: GrantFiled: October 10, 1997Date of Patent: July 27, 1999Assignee: Seagate Technology, Inc.Inventors: Raquib U. Khan, Hans Leuthold, David J. Jennings, Gregory I. Rudd, Gunter K. Heine
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Patent number: 5533812Abstract: A thrust plate with grooved surfaces within a hydrodynamic bearing establishes pressure gradients which cause the lubricating fluid for the bearing to reliably remain within the region of the hydrodynamic bearing, with the pressure gradient imposed on the fluid causing the fluid to flow toward the center of the bearing rather than to be caused to be forced outward toward the far end of the bearing which could potentially result in a leakage of the fluid.Type: GrantFiled: July 22, 1994Date of Patent: July 9, 1996Assignee: Seagate Technology, Inc.Inventors: Hans Leuthold, David J. Jennings, Gunter Heine, Lakshman Nagarathnam
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Patent number: 5524986Abstract: A hydrodynamic bearing incorporates a flexible membrane at one end of the fluid gap in the hydrodynamic bearing. If voids exist in the fluid, and if changes in the size of these voids or bubbles occur with changes in temperature or pressure in which the disc drive is being used, then the volume of the fluid will change, and increase relative to the change in size of the volume of the surrounding physical part. The flexible membrane will yield to the increased pressure of the increasing volume of the fluid. The membrane essentially acts as a spring whose spring force is overcome by the pressure created by or accompanying a increase in volume of the fluid. As this happens, the spring force of the membrane is overcome, the membrane relaxes and forms a bladder, effectively increasing the volume in which the lubricating fluid is contained, and preventing its escape or being forced out of the inner region of the bearing.Type: GrantFiled: August 2, 1994Date of Patent: June 11, 1996Assignee: Seagate Technology, Inc.Inventors: Hans Leuthold, Coda H. Pan, David J. Jennings, Lakshman Nagarathnam, Raquib U. Khan, Wesley R. Clark, Gunter Heine
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Patent number: 5520038Abstract: A moveable cage which has a pattern of holes surrounding and concentric with a central axis of the cage, and a short hard pin located within the cage, and movable back and forth between the two ends of the cage. A single drive device attached to the cage causes both translation and rotation of the cage. As the cage is advanced and rotated, the interior pin is caused to move backward and forward as the balls roll over the surface of the pin, so that the wear on the balls and on the surface of the interior pin is evenly distributed.Type: GrantFiled: July 22, 1994Date of Patent: May 28, 1996Assignee: Seagate Technology, Inc.Inventors: Wesley R. Clark, David J. Jennings
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Patent number: 5487608Abstract: The present invention includes four sections or partitions: two thrust bearings which are formed by the sides of a grooved thrust plate and corresponding countersurfaces, the thrust bearings designed to cause fluid flow in a single direction up around the rotating thrust plate and upward along the surface of a rotating journal, and two journal bearings formed side-by-side on the journal formed between a rotating shaft and a bushing with multiple spiral-grooved sections being formed on the rotating shaft or in the stationary bushing. The two journal bearings are separated by a circumferential groove in the shaft which is connected by a radial bore to a hollow reservoir in the shaft for providing fluid to the journal bearing and the thrust bearing. By providing this bore and a second bore located near to the thrust bearing, the boundary conditions for the combined journal bearings and thrust bearings are fixed and a stable rotating shaft is achieved.Type: GrantFiled: July 22, 1994Date of Patent: January 30, 1996Assignee: Seagate Technology, Inc.Inventors: Hans Leuthold, David J. Jennings, Wesley R. Clark, Raquib Khan, Guenther Heine
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Patent number: 5457589Abstract: A specially designed disc-mounting hub is provided having a disc-mounting flange protruding from a substantially cylindrical hub portion. A disc-mounting flange has a raised surface about the periphery of the flange upon which the disc rests. A lapped or ground spacer rests on the surface of the hub above the flange, and the disc in a single disc system or the bottommost disc in a multiple disc system rests upon this spacer. The opposite side of the disc in a single disc device is then clamped in place; if a plurality of discs are being utilized, the remainder of the discs are alternately stacked with spacer rings upon the first disc. A clamping ring is attached opposite the disc or discs-mounting flange and working cooperatively with the flange and ground spacer imparts a force upon the disc and spacer ring stack to hold the discs in place.Type: GrantFiled: March 2, 1994Date of Patent: October 10, 1995Assignee: Seagate Technology, Inc.Inventors: Hans L. Leuthold, David J. Jennings, Gerold Heiner, Donald J. MacLeod