Abstract: A multinode, multicast communications network has a distributed control for the creation, administration and operational mode selection operative in each of the nodes of the network. Each node is provided with a Set Manager for controlling either creation of, administration or access to a set of users to whom a multicast is to be directed. The Set Manager maintains a record of the local membership of all users associated with the node in which the Set Manager resides. A given Set Manager for each designated set of users is assigned the task of being the Set Leader to maintain membership information about the entire set of users in the multicast group. One of the Set Managers in the communications network is designated to be the Registrar which maintains a list of all the Set Leaders in the network. The Registrar insures that there is one and only one Set Leader for each set of users, answers inquiries about the membership of the sets and directs inquiries to appropriate Set Leaders if necessary.

Abstract: A video distribution management system utilizes a shared video library and a wide area network to deliver video files to local caches on the local area networks serving a subset of local viewing stations. A combination of direct local cache access, scheduled future local cache access and speed match distribution of video files makes the overall system both efficient and economical. In particular, a locally stored preface of a video file can be immediately viewed on the local area network while the balance of the video file is transmitted from the remote video library.

Abstract: A packet communications network includes a route testing system which launches a plurality of route testing messages from the source node to each of the nodes along the route, including the destination node, and returning to the source node. Time stamps in each of theses testing messages are compared to reception times to determine round trip delays which can be halved and compared to determine link transit times. These link transit times can, in turn, be analyzed to localize congestion or identify failed resources. The source resource is where the data is accumulated for the entire path and then analyzed to determine the location of failed links, if any, the response time from the source to the destination, the response time of each resource in the path, and the location of congested links. Packet switched resources identify the path test command themselves and carry out the testing procedure. Circuit switched resources utilize the control point controlling that resource to carry out the testing procedure.

Abstract: Packet messages transmitted on a packet communications network include origin and destination addresses in the form of stacked address elements which can be pushed or popped off of the stack. A plurality of interconnected packet communications network include routing nodes which utilize the top address element on the destination stack to route the message. Such routing nodes also include stack element editing facilities for popping elements from the stacks, constructing new elements to be pushed onto the stacks, and amending the contents of elements on the stack. This arrangement allows messages to be launched on the networks where the originating station does not have full knowledge of the destination station, and the routing nodes add the necessary destination information as it becomes necessary for routing.

Abstract: A multi-path channel interface for computer input-output systems includes the ability to define and activate unbalanced groups of unidirectional communications sub-channels for a user application. Protocol independent exchange identifications permit not only unbalanced transmission groups but also allow user-controlled extensions for negotiating the values of transmission parameters at the time the transmission group is activated. When error correcting re-transmissions force the re-segmenting of data blocks, second level sub-segment indexing assure the proper order of delivery of the various segments and sub-segments. The exchange identifications include an identification of the user protocol being supported and thus permit interfacing with any user protocol.

Abstract: A management system for local area networks ensures selected levels of quality of service to all transmission requests submitted to the management system. This management system is attached to the network and receives requests from all other stations on the network to reserve facilities for a particular quality of service data stream. An allocator in the management system determines if the requested facilities are available and, if so, reserves these facilities for the requesting station. If the facilities are not available, the request is denied. A hierarchical data base containing all of the current parameters of all of the network resources and all of the currently supported data streams is used to support the allocation process.

Abstract: A packet communications network in which multicast transmissions are made reliable by transmitting acknowledgements to all neighbors of every receiving node, including the source node. This allows the relinquishment of message holding buffers as soon as all near neighbors acknowledge receipt of the message after only tile longest round trip time to the nearest neighbors, rather than the round trip to the furthest destination. Moreover, highly reliable ancillary point-to-point transmission facilities can be used to retransmit multicast messages indicated as being lost by failure of acknowledgment. Finally, network partitions occurring during the multicast procedure do not necessarily lose the multicast message to the remote partitions since any node receiving the message can insure delivery to all other nodes in that partition.

Abstract: A packet communications network is adapted for efficiently handling of multi-priority traffic (such as multi-media traffic) by defining an access algorithm that not only ensures the requested loss probabilities for both priorities of traffic, but also optimizes the bandwidth required to carry both priority classes. A buffer having a properly sized occupancy threshold admits high priority traffic if there is room in the buffer, but admits lower priority traffic only if the buffer occupancy is below the occupancy threshold. The resulting consolidated multi-priority traffic can then be characterized by an effective bandwidth which increases the packet network capacity substantially. The multi-priority access mechanisms require little or no changes in the prior art access mechanisms and utilize pre-existing leaky bucket, route selection and link metric mechanisms of the prior art.

Abstract: A system for interconnecting widely separated local area networks (LANs) by means of a wide area network (WAN) utilizes network level facilities to establish a connection through the wide area network and to create connection table entries at the WAN access point which allow subsequent data frames to be transmitted through the wide area network without such network level operations. More particularly, the various LANs are combined into search groups, represented by address prefixes, to which LAN-initiated connection requests can be broadcast and which can respond so as to establish the data path connections. This system has the connection flexibility of a prior art router and, at the same time, the low overhead of a prior art bridge.

Abstract: A direct current to direct current converter utilizes a MOSFET half-bridge configuration in which the inherent magnetizing and leakage inductances of the transformer are used as the only inductances in the frequency-determining circuit. Diodes are used to limit the voltages across the capacitor of the frequency determining circuit and hence limit the short circuit and open circuit characteristics of the converter. A self-starting circuit insures that the circuit will start up when initially energized.

Abstract: In a packet communications network, the addition or deletion of a connection to the network by a user is governed by a link traffic metric which represents the effective capacity of each link in the network which participates in the packet connection route. The link metric is calculated in real-time and updated by simple vector addition or subtraction. Moreover, this link metric is also used to calculate leaky bucket parameters which govern the access of packets to the network once the connection is set up. A packet network using these link metrics and metric generation techniques provides maximum packet throughput while, at the same time, preserving grade of service guarantees.

Abstract: A vaginal speculum is disclosed in which a ratcheted linear motion of a thumb pad is translated into a complicated linear, rotational and retractive motion of the speculum paddles to provide anatomically correct motions for dilation of the vagina and the cervix without complicated two-handed adjustments of the speculum. Cam follower pins follow the contours of a cam slot to translate the linear motion into the required complicated motions of the speculum paddles. The ratchet permits easy locking at any degree of opening while unlocking is accomplished simply by depressing the thumb pad to disengage the pawl from the ratchet bars. A fluid reservoir is built into the speculum to capture fluids discharged during examination.

Abstract: An electronic equipment cabinet is shown having an integrated cover panel which provides a plurality of connector receptacle positions to which outside equipment may be connected. Connector contacts are snap locked into the receptacle positions. The connector receptacle contacts are automatically bridged when the mating connector plug is removed to short circuit the connector contacts. L-shaped bridging contacts maintain positional stability while L-shaped connector contacts permit direct insertion of the contacts into a printed circuit board within the equipment cabinet. Two unitary ground strips are fashioned to provide shielding shrouds around each of the plurality oconnector receptacles while attaching as single units to the cover panel and closing ground contact with the cabinet housing. This cabinet arrangement finds one use as a trunk access unit to interconnect a plurality of data stations into a local area ring network.

Abstract: A portable wet paint brush holder which is formed by a substantially rectangular bottom panel, vertical front and rear walls, and substantially rectangular side walls forming an enclosure with a top opening for receiving the brush portion of a conventional paint brush having the handle extending in an upward direction. One of the side walls of the holder is substantially vertical, but the other is outwardly inclined from the vertical at the bottom by an acute angle of the order of thirty degrees so that the enclosure top opening is larger than the bottom portion. A flexible clip is attached to the rear wall adjacent to the angled side wall and the top of the rear wall for holding the paint brush handle and a flexible hinged gripper extends from the rear wall at the top for securing the holder to an external object such as the painter's belt or to a ladder strut or the lip of a paint can.

Abstract: A pivotable pull ring is permanently attached to a low profile electrical plug by fashioning a locking stub at the attaching ends of the pull ring. Matching lock stub cavities in the electrical plug have "one-way" locking tabs which accept the locking stubs into the locking cavity during assembly, but which block the removal of the locking stub from the locking stub cavity once the locking stub is assembled into the locking stub cavity. The locking tab has a gentle ramp on the outside, to facilitate displacement of the locking tab to allow entry of the locking stub during assembly, but has an abrupt shoulder on the inside to prevent displacement of the locking tab after assembly.

Abstract: An electronic equipment cabinet is shown having an integrated cover panel which provides a plurality of connector receptacle positions to which outside equipment may be connected. Connector contacts are snap locked into the receptacle positions. The connector receptacle contacts are automatically bridged when the mating connector plug is removed to short circuit the connector contacts. L-shaped bridging contacts maintain positional stability while L-shaped connector contacts permit direct insertion of the contacts into a printed circuit board within the equipment cabinet. Two unitary ground strips are fashioned to provide shielding shrouds around each of the plurality of connector receptacles while attaching as single units to the cover panel and closing ground contact with the cabinet housing. This cabinet arrangement finds one use as a trunk access unit to interconnect a plurality of data stations into a local area ring network.

Abstract: An image processing system is disclosed in which the various image processing circuits are arranged in a pipeline such that the output of each circuit is passed on to the next circuit in the pipeline without storing the data between circuits of the pipeline. The individual processing circuits are program-controlled by a common controller in order to properly synchronize various operations such as scanning, compressing, expanding, rescaling, windowing and rotating. The rescaling operation is carried out by executing a sequence of program instructions applying to single pixels, or to single lines of the image. These instructions include deletion, duplication and passing through of the image element. Windowing is provided by inserting start-of-window and end-of-window instructions in the appropriate places in the sequence of rescaling instructions.

Abstract: A collapsible protective carton of corrugated cardboard is constructed from either one or two blanks and contains a suspended product protecting cradle dividing the carton interior into upper, lower, and central compartments. The central compartment is the primary product holding compartment, while the upper and lower compartments provide both protection against crushing and potential additional storage space for flat items such as instruction manuals or computer disks. At each end of the carton, a diagonal web member assists in locating the product in the center of the carton and provides additional protection against blows or pressure upon either end of the assembled carton. Cut-outs in two of the panels defining the central compartment serve not only to help position the central compartment within the outer carton but also to weaken those panels sufficiently to permit light products to deform the diagonal web members more readily if the carton should be dropped.

Abstract: A multiconductor shielded connector is disclosed in which a flexible, compressible double bushing is used between the connector half shells and the multiconductor cable. The double bushing comprises an outer bushing dimensioned to grasp the outer jacket of the cable at the exiting end of the connector. A concentric, longitudinally offset inner bushing is inserted under the shielding (braid or foil) and mates with ridges on the inner surface of the half shells to form a tight, continuous radiation seal. The inner and outer bushings are connected together with a fine web which maintains concentricity and axial displacement of the bushings before and during assembly, but which does not interfere with the operation of the connector after assembly. The outer bushing may have a sleeve extending outside of the half shells to prevent sharp bends at the connector exit. A single bushing can be used which defines a serpentine cable path when it is desired to use the same half shells with non-shielded cable.

Abstract: A multiconductor shielded connector is disclosed in which a flexible, compressible double bushing is used between the connector half shells and the multiconductor cable. The double bushing comprises an outer bushing dimensioned to grasp the outer jacket of the cable at the exiting end of the connector. A concentric, longitudinally offset inner bushing is inserted under the shielding (braid or foil) and mates with ridges on the inner surface of the half shells to form a tight, continuous radiation seal. A ferrite ring is inserted into a recess on the inner diameter of the inner bushing to provide noise suppression for signals traveling through the conductors of the cable. The inner and outer bushings are connected together with a fine web which maintains concentricity and axial displacement of the bushings before and during assembly, but which does not interfere with the operation of the connector after assembly.