Abstract: A communication system (10) implemented to be specifically matched to the time and spatially dependent statistics of a transmission channel (36). The communication system (10) is used for broadcasting over the channel (36) to users in a coverage region (18). The communication system (10) includes a transmitter (12) having an error correction encoder (30) and a weighted interleaver (32). The error correction encoder (30) includes a first input to receive data bits and a first output. The error correction encoder (30) expands each data bit received at said input by an encoder rate. The weighted interleaver (32) includes a second input to receive the expanded data bits and a second output. The weighted interleaver (32) has a non-uniform delay distribution between a minimum delay and a maximum delay to interleave the expanded data bits by the non-uniform delay distribution.

Abstract: A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users. The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization. The spectrum of the terminal links may be divided into multiple subbands (e.g., 38), each of which may support multiple (e.g., 80) ODS-CDMA channels.

Abstract: A communication system (10) implemented to be specifically matched to the time and spatially dependent statistics of a transmission channel (36). The communication system (10) is used for broadcasting over the channel (36) to users in a coverage region (18). The communication system (10) includes a transmitter (12) having an error correction encoder (30) and a weighted interleaver (32). The error correction encoder (30) includes a first input to receive data bits and a first output. The error correction encoder (30) expands each data bit received at said input by an encoder rate. The weighted interleaver (32) includes a second input to receive the expanded data bits and a second output. The weighted interleaver (32) has a non-uniform delay distribution between a minimum delay and a maximum delay to interleave the expanded data bits by the non-uniform delay distribution.

Abstract: A weighted interleaving system (10) is used for correlated channel coding. The weighted interleaving system (10) includes a weighted interleaver (12) having a pseudo-random demultiplexer (18), a first branch (28), a second branch (30), a third branch (32) and a pseudo-random multiplexer (38). The pseudo-random demultiplexer (18) receives input data bits at an input (20) and randomly distributes the input data bits to first (22), second (24) and third (26) outputs of the pseudo-random demultiplexer (18). The first branch (28) in communication with the first output (22) delays the transmission of the input data bits routed to it by a minimum delay. The second branch (30) in communication with the second output (24) delays the transmission of the input data bits routed to it by a delay uniform in probability from the minimum delay to a maximum delay. The third branch (32) in communication with the third output (26) delays the transmission of the input data bits routed to it by the maximum delay.

Abstract: A weighted interleaving system (10) is used for correlated channel coding. The weighted interleaving system (10) includes a weighted interleaver (12) having a pseudo-random demultiplexer (18), a first branch (28), a second branch (30), a third branch (32) and a pseudo-random multiplexer (38). The pseudo-random demultiplexer (18) receives input data bits at an input (20) and randomly distributes the input data bits to first (22), second (24) and third (26) outputs of the pseudo-random demultiplexer (18). The first branch (28) in communication with the first output (22) delays the transmission of the input data bits routed to it by a minimum delay. The second branch (30) in communication with the second output (24) delays the transmission of the input data bits routed to it by a delay uniform in probability from the minimum delay to a maximum delay. The third branch (34) in communication with the third output (26) delays the transmission of the input data bits routed to it by the maximum delay.

Abstract: A computer-implemented preferred materials selector tool comprises a digital processor, a data storage medium accessible by the digital processor, and a data base stored in the data storage medium having a plurality of entries for materials. At least some of the data base entries include identification of the physical character of the material, identification of a procedure in which the material is operable, and a hazard/environmental assessment. The computer-implemented tool further includes a set of instructions executable by the digital processor for controllably selecting a material from the data base responsive to a comparison with the physical character of the material, the procedure identification, or the hazard/environmental assessment.

Abstract: An electrical switch apparatus comprising at least one set of contacts including a movable contact and a stationary contact, at least one chamber surrounding the contacts, a first support for supporting the chamber, a second support for supporting the stationary contact with respect to the chamber, an adhesive for attaching the first and second supports to the chamber, a non-circular drive shaft, a connection mechanism for coupling the moving contact to the drive shaft, a locating mechanism for securing the connection mechanism along the drive shaft, a coupling mechanism associated with the drive shaft for transmitting rotational energy to the drive shaft, the coupling mechanism having an adaptor that mates with the drive shaft with a clearance between the adaptor and the shaft, and a castable material filling the clearance to form an interface between the drive shaft and the adaptor.

Abstract: A switch apparatus comprising a switch mechanism including a first contact, and a second contact movable into and out of engagement with the first contact for respectively closing and opening the switch mechanism, an operating rod assembly connected to the second contact for moving the second contact into and out of engagement with the first contact in response to movement of the operating rod assembly, the operating rod assembly including an operating rod having an outer surface, a first end adapted to be connected to a prime mover, and an opposite second end, and a conductive member connected to the second end of the operating rod and to the second contact, the conductive member having a construction for reducing the magnitude of electrical stress adjacent the outer surface and for positioning electrical stress away from the outer surface, and a pressure vessel for enclosing the switch mechanism and the operating rod assembly and surrounding the switch mechanism and the assembly with dielectric gas.

Abstract: Apparatus for opening and closing a switch, which apparatus comprises a lever mounted on a frame for pivotal movement between a first position and a second position, a first spring biasing the lever from the second position to the first position, a cam and follower for effecting pivotal movement of the lever from the first position to the second position against the influence of the first spring, a step on the cam for permitting movement of the lever from the second position to the first position under the influence of the first spring after the lever has moved from the first position to the second position, a member adapted to be connected to the switch and movable between a switch opening position and a switch closing position, which member is movable to the switch closing position in response to movement of the lever from the second position to the first position, a second spring displaceable between extended and contracted conditions, which second spring is extended to the extended condition in response t

Abstract: A switchgear apparatus comprising a row of pressure vessels, a frame including first and second generally horizontal, elongated members rigidified by the row of pressure vessels, an outer housing including a generally horizontal top portion supported by the frame, generally vertical, spaced apart side portions connected to the top portion, and a door which is movable between a lowered, closed position in which the door prevents access to the interior of the housing and a raised, open position in which the door affords access to the interior of the housing, the door including a generally planar first portion connected to the top portion for pivotal movement relative thereto about a generally horizontal axis, the first portion being angularly spaced from the top portion when the door is in the raised position, a mechanism for assisting manual movement of the door from the lowered position to the raised position, and a mechanism for releasably retaining the door in the raised position.

Abstract: A switch apparatus comprising a fixed tubular contact having an inner end, a movable tubular contact having an inner end and being movable between a closed position wherein the inner ends of the contacts overlap and an open position wherein the inner ends of the contacts are spaced apart, a piston fixed to the movable contact for movement thereiwth, a cylinder slideably receiving the piston and cooperating with the piston to define a variable volume pressure chamber which decreases in volume as the movable contact moves from the closed position to the open position, and a housing fixed to the piston and having an inner surface which cooperates with the piston to define an arc chamber containing the inner end of the movable contact, the housing having therein an aperture through which the fixed contact extends when the movable contact is in the closed position, and the arc chamber communicating with the pressure chamber so that gas is forced from the pressure chamber into the arc chamber when the movable conta

Abstract: An load interrupter is disclosed having the characteristics of an ordinary puffer interrupter and a self-extinguishing gas flow interrupter. The load interrupter comprises a generally hollow cylinder which is adapted to be filled with an arc extinguishing fluid and which has an electrically insulated nozzle at one end. A piston is sealingly and slidingly disposed within the cylinder so as to be movable between a first and second position to change the internal volume of the cylinder that is in flow communication with the nozzled end. A stop limits the relative motion between the piston and the nozzled end of the cylinder. A spring biases the piston against the stop. One of the two contacts across which the arc is formed is carried by the piston. The other contact is operated by a prime mover to move into and out of the chamber formed by the piston, cylinder and nozzle. Thus, under low current conditions, the piston follows the movement of the other contact.

Abstract: A unique self-flow generating gas interrupter of the type wherein arc-extinction is performed by the creation of a negative pressure region brought about by the separation of the interrupter contacts. The interrupter incorporates a novel arrangement of valves so as to optimize the performance of the interrupter over the broad range of interrupting currents. In one embodiment a check valve is used to supply gas from the exterior of the interrupter casing and into the arcing chamber in response to the pressure within the arcing chamber decreasing or falling below a pre-selected value. In this manner, less force is required to operate the interrupter when low-currents are encountered. In another embdiment a relief valve is used to release the pressure developed in the arcing chamber in the event that a large interrupting current is encountered. Still another embodiment incorporates both the check valve and the relief valve.

Abstract: An interrupter is provided having: an outer enclosure or tank adapted to contain an arc-extinguishing fluid; a fixed tubular electrical current carrying member disposed at one end of the tank; a movable tubular current carrying member disposed in the tank in an end-to-end relationship with the fixed electrical current member; a prime mover for stroking the movable current carrying member between an open position and a closed position; an electrically conductive piston means, carried by the movable electrical current carrying member, for supplying pressurized fluid into the gap formed between two current carrying members when the interrupter is opened and for purging the vicinity of the gap when the interrupter is closed; a non-electrically conductive base means, carried by the outer enclosure, for housing the piston means and for guiding the movement or the stroking of the movable current carrying member; and an insulated plenum means, carried by the piston means and disposed around the contacting ends of the

Abstract: An electrical circuit interrupter is disclosed having the characteristic of a puffer interrupter and a self-extinguishing gas flow interrupter. The interrupter comprises a generally hollow movable cylinder which is adapted to be filled with an arc extinguishing fluid and which has an opening at one end. A piston is sealingly and coaxially disposed within the cylinder so as to be movable between a first and second position to change the internal volume of the cylinder in flow communication with its opening. A fixed guide is provided to direct the motion of the piston within the cylinder. A stop is carried by the guide to limit the relative motion between the piston and the cylinder. A spring biases the piston against the stop. Disposed at the open end of the cylinder is an arc site such that the pressure within the cylinder increases as the energy released from the arc increases. One of the two contacts across which the arc is formed is carried by the cylinder.