Patents Represented by Attorney Ronald E. Myrick
  • Patent number: 5163551
    Abstract: This invention relates to a carrier for transporting integrated circuit devices. In particular, the carrier is configured to cradle devices which have preformed leads which usually extend around the perimeter of the device and tend to be fairly fragile. The carrier is made up of a carrier top and a carrier bottom, which are securely closed through the attachment of several spring clamps. The bottom provides a secure nest which is configured to the shape of the body of the device. The top includes a hold-down member which houses two rings, a compression ring and a contact ring, within a channel. The compression ring is made of a rubber like material that can elastically compress under contact pressure, while the contact ring is made of a hard material, which will not stick to the top of the device. The contact ring, which is positioned between the compression ring and the device, engages the device when the carrier top and the carrier bottom are mated.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: November 17, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Ram D. Bhatia
  • Patent number: 5161193
    Abstract: Cryptographic apparatus, and a related method for its operation, for in-line encryption and decryption of data packets transmitted in a communication network. A full-duplex cryptographic processor is positioned between two in-line processing entities of a network architecture. For example, in a fiber distributed data interface (FDDI) network, the processor is positioned between a media access control (MAC) sublayer and a ring memory controller (RMC). Incoming information packets are analyzed to decide whether or not they contain encrypted data and, if they do, are subject to decryption before forwarding. Outbound information packets have their data portions encrypted if called for, and are usually forwarded toward the network communication medium. Cryptographic processing in both directions is performed in real time as each packet is streamed through the processor.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: November 3, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Butler W. Lampson, William R. Hawe, Amar Gupta, Barry A. Spinney
  • Patent number: 5158912
    Abstract: An injection molded aluminum nitride heatsink forms the substrate of an integral heatsink semiconductor package in which a semiconductor chip is attached directly to the integrated heatsink forming an intimate thermal relationship between the heat generating source and the heat dissipating means. In a first embodiment, a planar surface of the heatsink component provides the substrate for the attachment of a semiconductor chip and a multilayer housing formed from a plurality of layers of dielectric glass ceramic lamina and conductive circuit layers. The multilayer housing is formed on top of the heatsink substrate creating a recessed cavity in which the semiconductor die sits and is attached directly to the heatsink. The semiconductor chip is attached to the circuit layers of the housing through any of the known electrical connection methods, such as wirebonding or tab tape. A cover plate is mounted over the cavity.
    Type: Grant
    Filed: April 9, 1991
    Date of Patent: October 27, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Dave Kellerman, Robert J. Hannemann, Stanley J. Czerepak, Robert J. Simcoe
  • Patent number: 5156371
    Abstract: A triaxially-equalized action shock and vibration-insulation mount is provided for the protection of a dynamic load-sensitive component, such as a mass-storage device, from external multidirectional dynamic loads above a predetermined magnitude. A substantially uniform, attenuated response of the component to such dynamic loads is the result, regardless of the direction of application of the loads. In order to achieve substantially uniform reactions to such external loads applied along any of the three orthogonal spatial axes, and further in order to achieve higher structural integrity of the mount by reducing flexural, tensile and/or shear stresses, the shock mount comprises a body of elastic, preferably foamed elastomer material, which is confined at its periphery in a rigid, stationary shell, substantially symmetrical relative to the orthogonal spatial axes and partially open at one side. The elastic material body is shaped at its geometrical center to provide a tight, e.g.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: October 20, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Victor M. Samarov
  • Patent number: 5157673
    Abstract: A masking comparison circuit outputs a signal "non-correspondence" if two binary signals received are unequal. However, there are provided masking means for masking this non-correspondence signal unless both binary signals for some time have been stable and, moreover, different. A comparison circuit of this kind forms part of, for example a data processing device based on redundancy.
    Type: Grant
    Filed: March 7, 1990
    Date of Patent: October 20, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Fredericus H. J. Feldbrugge
  • Patent number: 5155726
    Abstract: A technique for establishing and maintaining full duplex communication between two stations connected to a token ring network, without physically reconfiguring the station connections or otherwise disturbing the network. In an auto-configuration full duplex mode of operation, each station ascertains whether there are only two active stations on the network and, if so, performs an exchange of frames with the other station to establish full duplex communication. One way to ascertain whether only two stations are active is for each station to transmit periodically a neighbor information frame, which contains the indentities of the source station and the source station's nearest upstream neighbor. Once established, full duplex communication can proceed at a greater bandwidth than communication in a token ring network, and without latency delays and distance limitations associated with token ring networks.
    Type: Grant
    Filed: January 22, 1990
    Date of Patent: October 13, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Barry A. Spinney, Henry S. Yang, William R. Hawe
  • Patent number: 5153794
    Abstract: An assembly and method for securing head suspension members on shelf segments of metallic or ceramic actuator arms in a disk drive. The assembly comprises an actuator arm with a reduced thickness shelf segment, at least one head suspension member, a staking member having particular attributes and a staking plate also having particular attributes. The assembly is designed such that forcible expansion of the staking member takes place exclusively within the material of the staking plate member. The method is formulated such that the constituent elements of the assembly are aligned, placed under compression and staked together wherein an interference fit is formed between the staking member and staking plate member and no forcible pressure from the staking procedure is transmitted to the actuator arm. The assembly and method are ideally utilized in a multi-disk disk drive in which a plurality of head suspensions are secured to multiple arms of a single actuator in a single procedure.
    Type: Grant
    Filed: December 7, 1990
    Date of Patent: October 6, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Sigmund Hinlein
  • Patent number: 5148969
    Abstract: This invention relates to an apparatus and method by which electronic components can be reclaimed from printed circuit boards. In the preferred embodiment, the reclamation system includes a conveyor which grasps the edges of the boards and holds them at an angle so that the component sides of the boards are facing downward. The conveyor carries the boards past infrared panels which heat each board, so that the solder bonding the components to a given board is made to reflow. While the solder is in a reflow state, each board is struck with a tapper, the impact of which has a tendency to dislodge the components. Falling components are caught in bins where they can be collected. In addition, the reclamation system is configured such that a number of operators are able to work in front of the boards passing on the conveyor. Therefore, if the tapper fails to dislodge any components on a given board, an operator can manually remove the components before the board is itself removed from the conveyor.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: September 22, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Bernard J. Boucher, Kerry S. Dinsmore, John A. Malesky, Douglas A. Brochu
  • Patent number: 5149210
    Abstract: A recording and/or reading head has a recording and/or read nose and is movably mounted. The head is preloaded against a record carrier with first and second preload values. A sensor device senses and maintains the distance between the record carrier and the nose constant. The preloading structure includes a spring loaded cam operated mechanism acting between the head and the record carrier via a spring loaded wheel secured to the head, the wheel engaging the record carrier. A switching mechanism switches the apparatus between the first and second preload conditions. The apparatus can print or operate with documents of different thicknesses.
    Type: Grant
    Filed: January 30, 1991
    Date of Patent: September 22, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Bjorn S. H. Eriksson
  • Patent number: 5150360
    Abstract: A method and related apparatus for establishing a point-to-point cross-link between two bridges in a bridged communication network. The bridged communication network is first configured in a loop-free arrangement by a spanning tree algorithm that selects which links of every bridge to activate in order to form the spanning tree active configuration. Then at least one cross-link not defined by the spanning tree configuration is established for routing of messages as an alternative to a spanning tree path. A protocol in each bridge ensures that no loops are formed and that only messages to preselected locations are passed over the cross-link. An optional optimization procedure measures message propagation times in both directions between the two bridges and over both the cross-link path and the spanning tree path, to determine whether to modify usage of the cross-link.
    Type: Grant
    Filed: March 7, 1990
    Date of Patent: September 22, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Radia J. Perlman, William Hawe, Anthony Lauck
  • Patent number: 5147679
    Abstract: A method and apparatus for providing radial uniaxial anisotropy in the soft magnetic layer of a magnetic recording disk is disclosed. While the soft magnetic layer is being deposited on the recording disk, the magnetic field. The alternating perpendicular magnetic field causes eddy currents to flow in the disk, in a circumferential direction. The eddy currents, in turn cause a magnetic field in a radial direction, thereby resulting in the desired radial uniaxial anisotropy.
    Type: Grant
    Filed: December 26, 1990
    Date of Patent: September 15, 1992
    Assignee: Digital Equipment Corp.
    Inventors: Michael L. Mallary, Kazuo Ishibashi, Hiroshi Sato
  • Patent number: 5146981
    Abstract: A cooling apparatus for a substrate with heat generating circuit devices mounted on a first side thereof. A second side of the substrate is coated with a first layer made of a releasing agent. A second layer made of a thermally conductive material having a low melting point is provided on the first layer. A heat sink is provided on the second layer, for radiating heat transmitted from the circuit device through the substrate, the first layer and the second layer. During the assembly, the apparatus is heated and compressed to reflow the second layer reducing any air pocket formed at the substrate-to-heatsink interface.
    Type: Grant
    Filed: November 14, 1991
    Date of Patent: September 15, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Victor M. Samarov
  • Patent number: 5148338
    Abstract: A disk drive for magnetic data storage media includes a spindle bearing arrangement having a rotatable portion surrounding and mounted by bearings on a stationary portion. A spindle hub having a cylindrical outer surface and a concentric interior cavity is rigidly attached to the rotatable portion of the spindle bearing arrangement. The cylindrical outer surface of the spindle hub provides a mounting surface for a stack of storage disks. A brushless direct current motor is mounted within the hub cavity. The rotor of the motor includes a sleeve rigidly attached to the floor of the spindle hub cavity and providing a return flux path for the motor. The spindle hub and the sleeve have distinct coefficients of thermal expansion and a radial spacing between the sleeve and the spindle hub allows for unconstrained thermal expansion of the sleeve and the spindle hub. The hub cavity floor incorporates a concentric annulus for accurate centering of the sleeve within the cavity.
    Type: Grant
    Filed: November 14, 1990
    Date of Patent: September 15, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Tave J. Fruge
  • Patent number: 5133667
    Abstract: An electrical connector serves to connect first and second opposed flex circuits. A female member supports a second of the flex circuits formed with a plurality of raised contact features. A male member supports a first of the flex circuits formed with a plurality of contact pads. A resilient pad received in a cavity in the surface of the female member underlies the second flex circuit and biases the raised contact features away from the female member. The male member is movable in a forward direction from a first position whereat the contact feature and the contact pad are disengaged through a second position whereat the contact feature and the contact pad are initially engaged at a first location to a third position compressing the resilient pad toward said female member.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: July 28, 1992
    Assignee: Digital Equipment Corporation
    Inventor: Stuart P. Daughtrey
  • Patent number: 5089948
    Abstract: An electrically isolated high speed optical switching arrangement for use as a computer over-voltage sensing circuit utilizing first and second optoisolator devices, the first having an input, a first signal from the output of a bus sensing circuitry which provides two complementary outputs, with the output voltage of the optoisolator controlling power-down circuitry for the computer in response to an over-voltage condition. A second control optoisolator has its output in parallel with a resistor in the base to emitter path of the first optoisolator. The complementary signal of the bus-sensing circuitry provides the input to the second optoisolator. During normal power conditions, the first optoisolator is conductive and the second is non-conductive.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: February 18, 1992
    Assignee: Digital Equipment Corporation
    Inventors: Peter J. Brown, Suresh Hariharan
  • Patent number: 4991078
    Abstract: A data processing system is described in which the available technology is used to provide high performance. The high performance is achieved by having a four-level pipeline for the central processing system, a simplified instruction set and an interface with the coprocessor unit that has a simple and efficient interface with the normal instruction execution. The apparatus implementing the central processing system is closely connected to the instruction set. A discussion of the implementation of the data processing system is provided.
    Type: Grant
    Filed: September 29, 1987
    Date of Patent: February 5, 1991
    Assignee: Digital Equipment Corporation
    Inventors: Neil C. Wilhelm, Judson S. Leonard
  • Patent number: 4975905
    Abstract: A local area network for interconnecting terminals and other users and data processing systems and other service providers over a communications link. The users and providers connect to the communications link by means of interface units each of which may connect to several users or providers. The interface units communicate over the communications link by means of messages. When a user requires the use of a service, the interface unit establishes a virtual circuit between it and the interface unit connected to the service provider and a service session which allows the user and the service provider to communicate over the virtual circuit. If several users connected to the one interface unit as the first user require services provided by providers which connected to the same interface unit as the first provider, they communicate in sessions over the same virtual circuits. The session messages are accumulated into single virtual circuit messages that are acknowledged in unison by the receiving interface unit.
    Type: Grant
    Filed: September 25, 1989
    Date of Patent: December 4, 1990
    Assignee: Digital Equipment Corporation
    Inventors: Bruce Mann, Darrell Duffy, Anthony Lauck, William Strecker
  • Patent number: 4975904
    Abstract: A local area network for interconnecting terminals and other users and data processing systems and other service providers over a communications link by means of interface units each of which may connect to several users or providers. The interface units communicate over the communications link by means of messages. When a user requires the use of a service, the interface unit establishes a virtual circuit between it and the interface unit connected to the service provider and a service session which allows the user and the service provider to communicate over the virtual circuit. If several users connected to the one interface unit as the first user require services provided by providers which connected to the same interface unit as the first provider, they communicate in sessions over the same virtual circuits. The session messages are accumulated into single virtual circuit messages that are acknowledged in unison by the receiving interface unit.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: December 4, 1990
    Assignee: Digital Equipment Corporation
    Inventors: Bruce Mann, Darrell Duffy, Anthony Lauck, William Strecker