According to one embodiment, a rotating electrical machine has a vibrating-element. The vibrating-element has spring bars and circular members which cover spring bars while a part is connected to spring bars. The spring bars are connected to first stator core connection portions, which are formed so as to be spaced out in a circumferential direction from each other at two locations on a side surface of the stator core. The stator frame is connected by the second stator core connection portions, which are formed by two locations which are different from the first stator core connection portions, of the stator core. The second stator core connection portions contain a position adjacent to a node portion of a circular mode of vibration of the stator core, in which antinodes and nodes of vibration alternately appear in the circumferential direction as the vibrating-element is attached to the stator core.

A rotating electrical machine such as a power generator or electric motor includes a rotor, which rotates together with a rotating shaft, and a stator, which is so formed as to surround the rotor from the radial-direction outside. The stator includes a cylindrical stator core, which is so formed as to surround the rotor, and a stator frame, which covers the stator core from the radial direction.
Because of the electro-magnetic pull force that occurs as the rotor rotates, electro-magnetic vibrations occur at the stator. It is necessary to prevent the electro-magnetic vibrations from transmitting to a base on which the rotating electrical machine is placed. As for the stator of a typical rotating electrical machine, an elastic body or the like is placed between the stator core and the stator frame so that the stator core is supported through the elastic body, thereby keeping the electro-magnetic vibrations from transmitting to the outside of the stator frame.
For example, in a 2-pole turbine generator, the electro-magnetic pull force that acts on the rotor vibrates in a circular mode of vibration, which has node portions of vibrations in the circumferential direction. In the 2-pole turbine generator, there are four node portions. The circular mode of vibration moves in the circumferential direction at the same frequency as a rotating speed of the rotor.
Meanwhile, like the electro-magnetic pull force, the stator vibrates in a four-node circular natural mode of vibration. The vibration mode of the stator is substantially the same as the vibration mode of the electro-magnetic pull force of the rotor. Therefore, the stator is excited severely. In this case, as the vibration mode of the electro-magnetic pull force (excitation force) increases, so does the natural mode of vibration of the stator.
The circumferential-direction distribution of the excitation force mode is represented by formula (1) because there are four node portions. In this case, the angle of the circumferential direction is represented by θ, and the magnitude of the electro-magnetic pull force of the rotor by F0.F(θ)=F0 cos(2θ)  (1)
Meanwhile, for the circumferential-direction distribution of the circular natural mode of vibration of the stator core, if the number of node portions is n, formula (2) is realized. In this case, the displacement in the circumferential direction is represented by x, and the amplitude thereof by x0.x(θ)=x0·cos(n·θ)  (2)
Accordingly, mode excitation force Fn is represented by formula (3).
                                                                        F                n                            =                                                          (                                  F                  ·                  x                                )                                                                                =                                                                            ∫                  0                                      2                                        π                                                                                F                    0                                                                                cos                                                                    (                                                  2                                                    θ                                                )                                                              ·                                          x                      0                                                                                cos                                                              (                                              n                        ·                        θ                                            )                                                                                ⅆ                    θ                                                                                =                                                          {                                                                                =                                                                              F                            0                                                    ·                                                      x                            0                                                                                (                                                  n                          =                          2                                                )                                                                                =                          0                                                                                (                                                  n                          ≠                          2                                                )                                                                                (        3        )
That is, in any cases other than n=4, orthogonality is realized. Accordingly, the mode excitation force comes to zero. Therefore, it is possible to ignore any mode response other than n=4.
The four-node natural circular mode of vibration includes two vibration modes. According to one vibration mode, antinodes of vibration (portions where the amplitude is large) are formed on, for example, a vertical central axis of a rotating-shaft-direction cross-sectional surface of the stator core. According to the other mode, the antinodes of vibration are formed on an axis that is tilted at 45 degrees from the above vertical central axis.
As for the distribution of both vibration modes, the nodes of vibration (where the amplitude becomes zero) are replaced with the antinodes of vibration. That is, at locations where antinodes emerge according to one vibration mode, nodes emerge according to the other vibration mode. Moreover, the natural frequency of one vibration mode is equal to that of the other vibration mode.
In the 2-pole turbine generator, the above four-node natural circular mode of vibration is excited by the excitation force of the rotor having substantially the same four-node circular mode of vibration. In each natural mode of vibration, the positions of nodes remain unchanged. Accordingly, in each mode response, the positions of nodes remain unchanged, and the other portions carry out harmonic vibrations in terms of time so as to be proportional to the shape of modes. Such a form of vibration is called a standing wave.
However, as in the case of the electro-magnetic pull force of the above rotor, the stator has two natural circular modes of vibration; the positions of nodes and antinodes of the vibration modes emerge differently from each other. A vibration mode that occurs on a real stator, which is calculated by superimposing responses of the two vibration modes, is in the same shape as the four-node circular mode of vibration as in the case of the excitation force.
If the vibration mode rotates at an angular speed of the rotor, the magnitude of the amplitude of the stator remains a certain value across the entire circumference. That is, in the response of each natural mode of vibration, there are node portions of vibration. However, in a real response obtained by superimposing the responses of the two vibration modes, no node portion emerges.
In this case, since the amplitude is uniform across the circumferential-direction entire circumference of the stator, it is difficult to prevent the electro-magnetic vibrations that occur at the stator from transmitting to the base on which the rotating electrical machine is placed.
As for a method of suppressing vibrations of the rotating electrical machine's stator caused by the electro-magnetic pull force of the rotor, the following is known, for example, as disclosed in Japanese Patent Application Laid-Open Publications No. 2003-088008, the entire contents of which are incorporated herein by reference, by having a polygonal cross-sectional surface of the stator core, the structural symmetry of the stator breaks, resulting in a reduction in vibration.


A belt-driven continuously variable transmission adapted to prevent a tilting motion of a sheave under high temperature.

A belt-driven continuously variable transmission adapted to change a speed ratio continuously using a driving belt is known in the art. The belt-driven continuously variable transmission is comprised of a primary pulley and secondary pulley arranged in parallel fashion, and a driving belt running on those pulleys to transmit power therebetween. Each of the pulleys is individually comprised of a fixed sheave integrated with a rotary shaft, and a movable sheave fitted onto the rotary shaft while being allowed to reciprocate thereon. A conical face is formed on an inner face (as will be called a "pulley face" hereinafter) of each sheave to be opposed to each other. Therefore, the driving belt being contacted to the pulley face transmits the power frictionally therebetween.
When transmitting a torque frictionally between the driving belt and the pulley, the movable sheave has to withstand a reaction force from the driving belt against a thrust force pushing the movable sheave, and when the torque being transmitted is increased, the reaction force is also increased. In this situation, the movable sheave is flexurally deformed by the reaction applied thereto. Consequently, a friction between the driving belt and the sheaves may be reduced and a speed ratio may be varied. Japanese Patent Laid-Opens Nos. 2010-181017 and 2000-170859 disclose belt-driven continuously variable continuously variable transmissions adapted to prevent a flexural deformation of the movable sheave. Specifically, Japanese Patent Laid-Open No. 2010-181017 discloses a belt-driven continuously variable continuously variable transmission in which a thrust force is applied to an outer circumferential portion and to an inner circumferential portion of the movable sheave. Meanwhile, Japanese Patent Laid-Open No. 2000-170859 discloses a belt-driven continuously variable continuously variable transmission in which a thrust force is applied to a portion of the movable sheave radially outside of a contact point at which the driving belt moved to the maximum diameter position comes into contact therewith.
Meanwhile, the flexural deformation of the movable sheave caused by a load applied thereto from the driving belt may be reduced by thus modifying the belt-driven continuously variable continuously variable transmission. However, the movable sheave is fitted onto the rotary shaft integrated with the fixed sheave, in other words, the rotary shaft of the fixed sheave is inserted into a hollow shaft of the movable sheave. That is, a slight clearance remains inevitably between an inner surface of the hollow shaft of the movable sheave and an outer surface of the rotary shaft of the fixed sheave. Therefore, the movable sheave may be inclined by a reaction force from the driving belt thereby reducing the friction force and changing a speed ratio unintentionally.

Belt-driven continuously variable transmission

Abstract: The belt-driven continuously variable transmission is comprised of a pair of pulleys individually comprised of a fixed sheave rotated integrally with a rotary shaft and a movable sheave fitted onto the rotary shaft while being allowed to reciprocate thereon, and a driving belt applied to the pulleys to transmit power therebetween. a stopper member is disposed on an outer circumferential side and in a side where the driving belt is not contacted with the movable sheave so as to prevent the movable sheave from being tilted to widen a width between the fixed sheave and the movable sheave holding the driving belt by a load from the driving belt.


A voice control method that allows vocal characteristics of a character to diversely be set in a computer game where characters are capable of voice output is provided. The voice control method comprises, converting a voice that is externally input or provided in advance, based upon attribute information on the character; and an output step for outputting the converted voice as voice of the character. According to this method, the voice produced by a character that appears in a computer game can be set in accordance with the character's characteristics and various voices for each character set by each player can be created.

1. Field of the Invention
The present invention relates generally to a voice control method for controlling the voice produced by a character that appears in a computer game, and more particularly, to a voice control method for changing the vocal characteristics of the voice of a character depending on attributes of the character.
2. Description of the Related Arts
Recent progress of communications technology has realized a creation of common networks by connecting family game consoles, personal computers, etc., found in homes via, e.g., telephone lines, as well as a creation of common networks by connecting terminal equipment disposed at stores such as game centers and game cafes via optical fibers or other dedicated lines. By way of such networks it has become possible for a plurality of participants to take part in real time in conversations ("chat") and for a plurality of players to take part in a common game.
For example, in games that are executed by a plurality of players via a network (hereinafter referred to as networked games), each player's game console (terminal apparatus) is connected to a server via the network, and by the communication of reciprocal information including information on each player's operation of each console through the server, a shared networked game can progress on each console.
In networked games each player, for example, may be represented by a character, and each player's character may fight with other characters as a combat game, or, for example, the players' characters may take part in an adventure together as a role playing game. In such games there may be a scene where the players can converse with each other using each player's character. Such a conversation may be realized, for example, by text data input by one player via a game console, the text data being sent via the network to the game console of another player and being displayed as a speech balloon in relation to a character on the screen.
FIG. 13 shows an example of such a speech balloon from a computer game screen. As shown in this figure a speech balloon containing the text is displayed next to the character and in this way the players conversation is conducted.
Moreover, due to the increasing capacity seen in the storage medium available to hold program data and the adoption of network-based distribution, it has become possible to handle larger amounts of data. For this reason a trend is developing for characters' speech, that was previously displayed entirely as text or expressed only partially as voice, to be entirely output as a voice.
Network games can be conducted with a greater sense of realism, if the characters are able to converse with each other directly using voice output instead of displaying text data in speech balloons.
When using voice output, a character's vocal characteristics may be set in advance or the player's voice may directly be output. However, setting a character's vocal characteristics in advance results in all players who choose this character having the same voice and thus making for a low level of variety. Likewise, outputting the player's voice unchanged can sometimes result in the voice being inappropriate to the character. For example, if a male player chooses a female character, this female characters ends up conversing in a male voice.


Rapid characterization and screening of polymer samples to determine average molecular weight, molecular weight distribution and other properties is disclosed. Rapid flow characterization systems and methods, including liquid chromatography and flow-injection analysis systems and methods are preferably employed. High throughput, automated sampling systems and methods, high-temperature characterization systems and methods, and rapid, indirect calibration compositions and methods are also disclosed. The described methods, systems, and devices have primary applications in combinatorial polymer research and in industrial process control.

The present invention generally relates to the field of polymer characterization. In particular, the invention relates to liquid chromatography and related flow-injection analysis techniques for rapidly characterizing polymer solutions, emulsions and dispersions, and to devices for implementing such techniques. In preferred embodiments, the characterization of a polymer sample or of components thereof is effected with optical detectors. The methods and devices disclosed herein are applicable, inter alia, to the rapid characterization of libraries of polymers prepared by combinatorial materials science techniques.
Currently, there is substantial research activity directed toward the discovery and optimization of polymeric materials for a wide range of applications. Although the chemistry of many polymers and polymerization reactions has been extensively studied, it is, nonetheless, rarely possible to predict a priori the physical or chemical properties a particular polymeric material will possess or the precise composition and architecture that will result from any particular synthesis scheme. Thus, characterization techniques to determine such properties are an essential part of the discovery process.
Combinatorial chemistry refers generally to methods for synthesizing a collection of chemically diverse materials and to methods for rapidly testing or screening this collection of materials for desirable performance characteristics and properties. Combinatorial chemistry approaches have greatly improved the efficiency of discovery of useful materials. For example, material scientists have developed and applied combinatorial chemistry approaches to discover a variety of novel materials, including for example, high temperature superconductors, magnetoresistors, phosphors and catalysts. See, for example, U.S. Pat. No. 5,776,359 to Schultz et al. In comparison to traditional materials science research, combinatorial materials research can effectively evaluate much larger numbers of diverse compounds in a much shorter period of time. Although such high-throughput synthesis and screening methodologies are conceptually promising, substantial technical challenges exist for application thereof to specific research and commercial goals.
Methods have been developed for the combinatorial (e.g., rapid-serial or parallel) synthesis and screening of libraries of small molecules of pharmaceutical interest, and of biological polymers such as polypeptides, proteins, oligonucleotides and deoxyribonucleic acid (DNA) polymers. However, there have been few reports of the application of combinatorial techniques to the field of polymer science for the discovery of new polymeric materials or polymerization catalysts or new synthesis or processing conditions. Brocchini et al. describe the preparation of a polymer library for selecting biomedical implant materials. See S. Brocchini et al., A Combinatorial Approach for Polymer Design, J. Am. Chem. Soc. 119, 4553-4554 (1997). However, Brocchini et al. reported that each synthesized candidate material was individually precipitated, purified, and then characterized according to xe2x80x9croutine analysisxe2x80x9d that included gel permeation chromatography to measure molecular weight and polydispersities. As such, Brocchini et al. did not address the need for efficient and rapid characterization of polymers.
Liquid chromatography is well known in the art for characterizing a polymer sample. Liquid chromatographic techniques employ separation of one or more components of a polymer sample from other components thereof by flow through a chromatographic column, followed by detection of the separated components with a flow-through detector. Approaches for liquid chromatography can vary, however, with respect to the basis of separation and with respect to the basis of detection. Gel permeation chromatography (GPC), a well-known form of size exclusion chromatography (SEC), is a frequently-employed chromatographic technique for polymer size determination. In GPC, the polymer sample is separated into components according to the hydrodynamic volume occupied by each component in solution. More specifically, a polymer sample is injected into a mobile phase of a liquid chromatography system and is passed through one or more chromatographic columns packed with porous beads. Molecules with relatively small hydrodynamic volumes diffuse into the pores of the beads and remain therein for longer periods, and therefore exit the column after molecules with relatively larger hydrodynamic volume. Hence, GPC can characterize one or more separated components of the polymer sample with respect to its effective hydrodynamic radius (Rh). Another chromatographic separation approach is illustrated by U.S. Pat. No. 5,334,310 to Frxc3xa9chet et al. and involves the use of a porous monolithic stationary-phase as a separation medium within the chromatographic column, combined with a mobile-phase composition gradient. (See also, Petro et al, Molded Monolithic Rod of Macroporous Poly(styrene-co-divinylbenzene) as a Separation Medium for HPLC Synthetic Polymers: xe2x80x9cOn-Columnxe2x80x9d Precipitation-Redissolution Chromatography as an Alternative to Size Exclusion Chromatography of Styrene Oligomers and Polymers, Anal. Chem., 68, 315-321 (1996); and Petro et al, Immobilization of Trypsin onto xe2x80x9cMoldedxe2x80x9d Macroporous Poly(Glycidyl Methacrylate-co-Ethylene Dimethacrylate) Rods and Use of the Conjugates as Bioreactors and for Affinity Chromatography, Biotechnology and Bioengineering, Vol. 49, pp. 355-363 (1996)). Chromatography involving the porous monolith is reportedly based on a precipitation/redissolution phenomenon that separates the polymer according to sizexe2x80x94with the precipitated polymer molecules selectively redissolving as the solvent composition is varied. The monolith provides the surface area and permeation properties needed for proper separation. Other separation approaches are also known in the art, including for example, normal-phase adsorption chromatography (with separation of polymer components being based on preferential adsorption between interactive functionalities of repeating units and an adsorbing stationary-phase) and reverse-phase chromatography (with separation of polymer components being based on hydrophobic interactions between a polymer and a non-polar stationary-phase). After separation, a detector can measure a property of the polymer or of a polymer componentxe2x80x94from which one or more characterizing properties, such as molecular weight can be determined as a function of time. Specifically, a number of molecular-weight related parameters can be determined, including for example: the weight-average molecular weight (Mw), the number-average molecular weight (Mn), the molecular-weight distribution shape, and an index of the breadth of the molecular-weight distribution (Mw/Mn), known as the polydispersity index (PDI). Other characterizing properties, such as mass, particle size, composition or conversion can likewise be determined.
Flow-injection analysis techniques have been applied for characterizing small molecules, such as pigments. Typically, such techniques include the detection of a sample with a continuous-flow detectorxe2x80x94without chromatographic separation prior to detection. However, such approaches have not, heretofore, been applied in the art of if polymer characterization. Moreover, no effort has been put forth to optimize such approaches with respect to sample-throughput.
A variety of continuous-flow detectors have been used for measurements in liquid chromatography systems. Common flow-through detectors include optical detectors such as a differential refractive index detector (RI), an ultraviolet-visible absorbance detector (UV-VIS), or an evaporative mass detector (EMD)xe2x80x94sometimes referred to as an evaporative light scattering detector (ELSD). Additional detection instruments, such as a static-light-scattering detector (SLS), a dynamic-light-scattering detector (DLS), and/or a capillary-viscometric detector (C/V) are likewise known for measurement of properties of interest. Light-scattering methods, both static and dynamic, are established in several areas of polymer analysis. Static light scattering (SLS) can be used to measure Mw and the radii of gyration (Rg) of a polymer in a dilute solution of known concentration. Dynamic light scattering (DLS) measures the fluctuations in the scattering signal as a function of time to determine the diffusion constant of dissolved polymer chains or other scattering species in dilute solution or of polymer particles comprising many chains in a heterogeneous system such as dilute emulsion or latex dispersion. The hydrodynamic radius, Rh, of the chains or particles can then be calculated based on well-established models.
Presently known liquid chromatography systems and flow-injection analysis systems are not suitable for efficiently screening larger numbers of polymer samples. Known chromatographic techniques can typically take up to an hour for each sample to ensure a high degree of separation over the wide range of possible molecular weights (i.e., hydrodynamic volumes) for a sample. The known chromatographic techniques can be even longer if the sample is difficult to dissolve or if other problems arise. Additionally, polymer samples are typically prepared for characterization manually and individually, and some characterization systems require specially-designed sample containers and/or substantial delay-times. For example, optical methods such as light-scattering protocols typically employ detector-specific cuvettes which are manually placed in a proper location in the light-scattering instrument. Such optical protocols can also require a sample to thermally equilibrate for several minutes before measurement. Moreover, because of the nature of many commercial polymers and/or polymer samplesxe2x80x94such as their non-polarity and insolubility in water and/or alcohols, their heterogeneous nature, their lack of sequence specificity, among other aspects, the methods, systems and devices developed in connection with the biotechnological, pharmaceutical and clinical-diagnostic arts are generally not instructive for characterizing polymers. Hence, known approaches are not well suited to the rapid characterization of polymers.
Aspects of polymer characterization, such as sample preparation and polymer separation, have been individually and separately investigated. For example, Pochxc3xa9 et al. report a system and approach for automated high-temperature dissolution of polymer samples. See Pochxc3xa9 et al., Use of Laboratory Robotics for Gel Permeation Chromatography Sample Preparation: Automation of High-Temperature Polymer Dissolution, J. Appl. Polym. Sci., 64(8), 1613-1623 (1997). Stationary-phase media that reduce chromatographic separation times of individual polymer samples have also been reported. See, for example, Petro et al., Molded continuous poly(styrene-co-divinylbenzene) rod as a separation medium for the very fast separation of polymers; Comparison of the chromatographic properties of the monolithic rod with columns packed with porous and no-porous beads in high-performance liquid chromatography., Journal of Chromatography A, 752, 59-66 (1996); and Petro et al., Monodisperse Hydrolyzed Poly(glycidyl methacralate-co-ethylene dimethacrylate) Beads as a Stationary Phase for Normal-Phase HPLC, Anal. Chem., 69, 3131 (1997). However, such approaches have not contemplated nor been incorporated into protocols and systems suitable for large-scale, or even moderate-scale, combinatorial chemistry research, and particularly, for combinatorial material science research directed to the characterization of polymers.
With the development of combinatorial techniques that allow for the parallel synthesis of arrays comprising a vast number of diverse industrially relevant polymeric materials, there is a need for methods and devices and systems to rapidly characterize the properties of the polymer samples that are synthesized
It is therefore an object of the present invention to provide systems and protocols for characterizing combinatorial libraries of polymer samples, and particularly, libraries of or derived from polymerization product mixtures, to facilitate the discovery of commercially important polymeric materials, catalysts, polymerization conditions and/or post-synthesis processing conditions. It is also an object of the invention to provide polymer characterization systems and protocols that can be employed in near-real-time industrial process control.
Briefly, therefore, this invention provides methods and apparatus for the rapid characterization or screening of polymers by chromatographic techniques and related flow-injection analysis techniques, and particularly, those employing optical detection methods. This invention provides a number of embodiments for such rapid characterization or screening of polymers and those embodiments can be employed individually or combined together. More specifically, polymer characterization approaches and devices are presented involving flow characterization and non-flow characterization, and with respect to both of the same, involving rapid-serial, parallel, serial-parallel and hybrid parallel-serial approaches. Some preferred approaches and embodiments are directed to rapid-serial flow characterization of polymer samples.
Among the several significant aspects of the rapid-serial flow characterization techniques are protocols and systems related to automated sampling, chromatographic separation (where applicable) and/or detectionxe2x80x94which individually and collectively improve the sample-throughput when applied to characterize a plurality of polymer samples. The automated polymer sampling can be effected at faster sampling rates, with equipment optimized for such purposes, and in sequences that benefit overall throughput and/or minimize extraneous steps. A number of chromatographic separation techniques can be employed to efficiently and effectively separate one or more of the various components of a heterogeneous polymer sample from one or more other components thereof. Generally, such techniques relate to column geometry, separation medium and mobile-phase medium. Certain approaches and systems disclosed herein involve improved aspects of detection. In addition, rapid, indirect calibration standards and methods impact overall system speed. Moreover, several important aspects of the invention have direct implications for high-temperature characterization efforts (typically ranging from about 75xc2x0 C. to about 225xc2x0 C.).
Many of such aspects of the invention can be directly translated for use with parallel or serial-parallel protocols, in addition to rapid-serial protocols. In a preferred embodiment, for example, a parallel or serial-parallel dynamic light-scattering system and protocols can be used for polymer characterization with very high sample throughput.
Hence the methods, systems and devices of the present invention are particularly suited for screening of arrays of polymerization product mixtures prepared in the course of combinatorial materials discoveryxe2x80x94thereby providing a means for effectively and efficiently characterizing large numbers of different polymeric materials. While such methods, systems and devices have commercial application in combinatorial materials science research programs, they can likewise be applied in industrial process applications for near-real-time process monitoring or process control.
Other features, objects and advantages of the present invention will be in part apparent to those skilled in art and in part pointed out hereinafter. All references cited in the instant specification are incorporated by reference for all purposes. Moreover, as the patent and non-patent literature relating to the subject matter disclosed and/or claimed herein is substantial, many relevant references are available to a skilled artisan that will provide further instruction with respect to such subject matter.

Targeted separation protocols for rapid characterizations of polymers


A method for transmitting packets in an RPR includes: pre-setting an MAC table having an item which is a corresponding relationship between the node MAC address and the UE MAC address of each node; an RPR node receiving an insert packet, performing the MAC table lookup, deciding whether an item matching a destination MAC address of the insert packet exists; if there exists the item, converting the insert packet to an extended frame-formatted packet where the RPR destination node MAC address equals to the node MAC address of the item and sending the converted packet to the destination node, and performing the corresponding process; if there does not exist the item, converting the insert packet to an extended frame-formatted packet where the RPR destination node MAC address equals to a broadcast MAC address, broadcasting the converted packet on the whole network, and performing the corresponding process.

Recently, with the rapid development of data services, the Ethernet technology has been used widely in the Metropolitan Area Networks (MAN), since it has some advantages, such as low cost, simple structure, as well as facilitations of transmitting and processing Internet Protocol (IP) data packets. However, the Ethernet technology can not effectively meet the current requirement of a MAN in the aspects of reliability and expansibility, since it lacks the Quality of Service (QoS) of the telecommunication level and the network management mechanism for fast protection/recovery and integrity. Hence, the RPR technology emerges as required.
RPR is a Multi-Service Transmission Platform (MSTP) technology that transmits services, e.g. data, voice, image, etc, by using the packet technology in a ring network structure. Integrating the intelligence of IP technology, the economical efficiency of the Ethernet and the high bandwidth efficiency as well as reliability of an optical ring network, RPR solves the QoS problems, such as the classification of service, and provides a favorable networking solution for the broadband IP MAN operators.
As shown in FIG. 1, the RPR adopts a dual-ring architecture that is composed of an external ring and an internal ring, wherein the transporting direction of the internal ring is opposite to that of the external ring; hence two transmission paths exist between a pair of nodes. In addition, when all of the nodes in the RPR are Layer3 data communication devices, e.g. Layer3 switches and routers, the packets transmission between the Layer3 devices may be implemented; when all of the nodes in the RPR are Layer2 data communication devices, e.g. Layer2 switches, the packets transmission between the Layer2 devices may be implemented.
In accordance with RPR protocols, the RPR implements communications between Layer2 devices by using the bridge mode. Specifically, the nodes in the RPR convert an insert packet came from a User Equipment (UE) to an extended frame-formatted packet and broadcasts it on the whole network. The nodes that receive the extended frame-formatted packet convert the packet to an Ethernet frame-formatted packet and send the Ethernet frame-formatted packet to the UE connected with it.
As shown in FIG. 2, the method for transporting a packet between Layer2 devices in an existing RPR includes the following steps:
Step 201: A node of the RPR receives an insert packet came from a UE.
Steps 202˜203: The nodes that receive the insert packet convert the format of the packet from the Ethernet frame format to the RPR extended frame format, and broadcast the converted packet to the whole network.
Generally, the format of the insert packet received by an RPR node is the Ethernet frame format. However, the packet transported in the RPR must conform to the RPR protocols. Thus, the node that receives the insert packet needs to perform the format conversion for the packet.
In accordance with the RPR protocols, the format of the packet transported in the RPR may be an RPR basic frame format or the RPR extended frame format. The RPR basic frame format is used in an RPR that is composed of Layer3 devices while the RPR extended frame format is used in an RPR that is composed of Layer2 devices. Table 1 shows the specific architecture of the RPR extended frame.
TABLE 1Length(Byte)FieldIndication1TTLTime To Live (TTL), indicates themaximal number of hops and issubtracted 1 each time the packetpasses one node in the forwardingprocess1BaseControlRPR frame control message6R_DmacMAC address of RPR destination node6R_SmacMAC address of RPR source node1TTLBaseoriginal value of the Maximal numberof hops of the RPR frame, remainsunchanged in the forwarding process1ExtendedControlRPR extended frame control field2HECHead error check6DmacExtendedExtended destination MAC address,i.e. MAC address of the destinationUE, the actual destination MACaddress of the Ethernet frame6SmacExtendedExtended source MAC address, i.e.MAC address of the source UE, theMAC address of the UE that initiatesthe Ethernet frameDataRemaining frame data4FCSFrame Check Sequence
A Layer3 device can identify the source IP address and the destination IP address carried in a packet, and need not use the Media Access Control (MAC) address to transmit and receive the packet. Thus the basic frame format used in the RPR that is composed of Layer3 devices does not have the two fields of SmacExtended and DmacExtended, compared with the extended frame format in the table 1.
Herein, when an Ethernet insert packet is converted to an RPR extended frame-formatted packet, the source MAC address carried in the packet is used as the SmacExtended field of the extended frame, the destination MAC address is used as the DmacExtended field of the extended frame, the MAC address of the node receiving the insert packet is used as the R_Smac field, and the broadcast MAC address is used as the R_Dmac field.
Upon completing the conversion of the insert packet from the Ethernet frame format to the extended frame format, the node receiving the insert packet sends out the converted packet by the way of broadcasting on the whole network.
Steps 204˜205: The nodes that receive the extended frame-formatted packet convert the format of the received packet to the Ethernet frame format, and determine the way of processing the packet according to the destination MAC address of the packet.
When the extended frame-formatted packet arrives at a node of the RPR, the format of the packet is converted from the extended frame format to the Ethernet frame format. The detailed method includes: removing the HEC field, the R_Dmac field, the R_Smac field and the BaseControl field of the extended frame-formatted packet, and using the MAC address indicated by the DmacExtended field as the destination MAC address of the Ethernet frame-formatted packet.
Then, according to the destination MAC address of the packet, the node receiving the packet checks if itself is connected with the destination UE of the packet or not. If it is connected with the destination UE, the node sends the Ethernet frame-formatted packet towards the UE corresponding to the destination MAC address; otherwise, processes the Ethernet frame-formatted packet according to the network configuration, e.g. discards the packet.
By now, the packet transmission process in the existing RPR network is completed.
As the broadcast mode is used in the packet transmission in the existing RPR networks, i.e. the extended frame-formatted packet, after being inserted in the ring from the source node, is respectively sent to the other nodes in the RPR except for the source node, the ring paths between the source node and the other nodes of the RPR are largely used, thereby occupying larger bandwidth and requiring more communication resources.

Method for transmitting message in a resilient packet ring network


An optical device includes an optical system mount plate, a casing, and a screw-hole forming part. An optical system is mounted on the optical system mount plate. The optical system mount plate is housed in the casing. The screw-hole forming part is provided on a bottom of the casing such that a screw provided on a tripod head can threadedly fit in the screw-hole forming part. The screw-hole forming part and at least one portion of the bottom are engaged with the optical system mount plate so as to counteract a rotational tightening force that is applied to the screw-hole forming part when the screw is threadedly tighten in the screw-hole forming part.

1. Field of the Invention
The present invention relates to an optical device having an optical system mount plate, on which an optical system is mounted, and a casing, in which the optical system mount plate is housed, and more particularly to an optical device in which a bottom of the casing is provided with a screw-hole forming part which is threadingly fit on a screw provided on a tripod head.
2. Description of the Related Art
As examples of optical devices, there are a binocular telescope, a camera, and so on. In these optical devices, an optical system mount plate is housed in the casing, and an optical system, such as an observation optical system and a camera, is mounted on the optical system mount plate. The optical device is usually designed to be fixed on a tripod head. Namely, a screw-hole forming part is provided on a bottom of the casing, and is threadingly fit on a screw of the tripod head, so that the optical device is attached on the tripod.
On the other hand, the optical device is required to be light weight. Therefore, aluminum, aluminum alloy, and reinforced plastic are used as material for the casing, and the thickness of the casing is required to be as thin as possible. Usually, the screw-hole forming part is integrally formed on the bottom of the casing, and has a large thickness so as to form a screw hole.
When the optical device is attached to the tripod head, it is often the case that excessive rotational force is exerted on the screw-hole forming part by tightening the screw of the tripod head to the screw-hole forming part. Due to this excessive rotational force, excessive stress occurs in the bottom of the casing, so that the casing may be deformed.
Thus, for lightening the weight of the optical device as a whole, it is desirable to reduce the thickness of the casing. However, for preventing deformation of the casing from occurring, because of the excessive stress when attaching the optical device onto the tripod head, it is not possible to reduce the thickness of the casing too much.


An apparatus for heating and conveying a granular material is disclosed, and which comprises an elongate trough, and a framework mounting a plurality of transverse blades mounted above the trough. The framework is moved along a closed path of travel so that the blades move through a forward stroke, a lifting stroke, a return stroke, and a downward stroke which returns the blades to their original position. Thus a granular material may be moved along the length of the trough in a series of sequential steps. Also, the blades are internally heated, and the bottom wall of the trough is also heated, to effect heating of the advancing granular material.

The present invention relates to an apparatus for heating and conveying a granular material, such as aggregate to be used in the manufacture of asphalt pavement, or recycled asphalt pavement, or oil contaminated soil.
In the production of asphalt pavement, it is known to heat granular materials, such as stone aggregate, in a rotary drum where the material to be heated is in direct contact with the hot gases coming from a burner. It is also known to heat granular materials in a screw conveyor which has hollow flights through which a heating fluid is circulated.
The above and other known processes for heating granular materials have disadvantages in the case of some materials, such as heat sensitive materials. For example, in the case of a screw conveyor, it is possible for a portion of the granular material to remain in contact with the heated flights throughout its passage through the conveyor, and so as to be overheated, while other portions are inadequately heated.
It is accordingly an object of the present invention to provide a heating and conveying apparatus for granular materials, and which overcomes the disadvantages and limitations of the prior systems.
It is also an object of the present invention to provide a heating and conveying apparatus which provides efficient transfer of heat to a granular material without exposing the material to excessively high temperatures, and which achieves substantially uniform heating of all portions of the material.
It is a further object of the present invention to provide a heating and conveying apparatus of the described type which has the ability to conveniently enclose the process so as to permit any released gases to be captured.


A Montgomery modular multiplier receiving a multiplicand (A), a modulus (M), and a multiplier (B), using a t-s compressor, where t>3 and s>1, and a multiplication method performed in the same. In response to a carry propagation adder signal, the t-s compressor performs additions on the carry C and the sum S and obtains the final results in a carry propagation adder structure.

This application claims priority from Korean Patent Application No. 10-2002-87243, filed on Dec. 30, 2002, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a public-key cryptographic system, and more particularly, to a Montgomery modular multiplier.
2. Description of the Related Art
Cryptographic systems are used in communications achieved through smart cards, IC cards, and the like and have developed from secret-key cryptographic systems to public-key cryptographic systems. In a secret-key cryptographic system, two users must share an identical secret key in order to communicate with each other. Hence, key management and digital signing, which are based on a secret-key cryptographic system, are difficult. On the other hand, in a public-key cryptographic system, a secret key is secured by each user and any user who knows the public key of another party can communicate with that party, facilitating a process of convenient secret communications.
Examples of a public-key cryptographic system include Ron Rivest, Adi Schamir, and Len Adleman (RSA), Diffie-Hellman, a Digital Signature Algorithm (DSA), an Elliptic Curve Cryptosystem (ECC), and the like. Since a public-key cryptographic system performs modular multiplication to achieve a modular exponentiation operation, the system must adopt a modular multiplier.
A Montgomery modular multiplication algorithm, known as the most effective modular multiplication algorithm, can be expressed in pseudo code, as in Algorithm 1 below:
[Algorithm 1]Stimulus:  A = (an-1 an-2 ... a1 a0)2, and A < M  B = (bn-1 bn-2 ... b1 b0)2, and B < M  M = (mn-1 mn-2 ... m1 m0)2, and M is odd.Response:  S = (Sn Sn-1 Sn-2 ... S1 S0)2 ≡ ABR−1 (mod M)Method:  S: = 0For i: = 0 to n-1 do  qi: = s0 XOR (bi AND a0)  S: = (S + biA + qiM)/2endfor
That is, in Algorithm 1, a final S (sum) (in Algorithm 1, carry is expressed as Sn) that is calculated in a "for" loop is congruent to ABR−1 (mod M). Here, "R−1" is an inverse number of R modular-multiplied for "mod M". When R is equal to 2n, "(R*R−1) mod M" is equal to 1.
The Montgomery modular multiplication algorithm performs only multiplications on given numbers A, B, and M, without using divisions, and is faster than other algorithms. Hence, the Montgomery modular multiplication algorithm is widely used in implementing public-key cryptographic systems, which require a modular exponentiation operation.
Conventional Montgomery modular multipliers based on a Montgomery modular multiplication algorithm are classified as a parallel multiplier, which uses a carry propagation adder as a basic accumulator, or a serial multiplier, which uses a 3-2 (3-input to 2-output) compressor (i.e., a carry save adder made up of full adders) as a basic accumulator.
A carry propagation adder requires a carry-propagation delay time on a clock-by-clock basis to propagate a carry upon every addition of multiple bits. Since the carry propagation adder cannot increase the carry-propagation delay time without limit, multiplication of numbers represented by 32 bits or more is difficult. In other words, the carry propagation adder has a larger power-delay product than in a carry save adder. The multiplication of a 32-bit number by a 32-bit number must be repeated in order to perform a multiplication of numbers represented by 32 bits or more.
Since a serial multiplier that uses a carry save adder uses a 3-2 compressor (i.e., full adders), there are no problems of a propagation delay time, but the serial multiplier with the carry save adder is not easily implemented in hardware. The 3-2 compressor removes the propagation delay time by performing all additions on each bit at as many clock pulses as the number of bits. In other words, in a Montgomery modular multiplication algorithm such as Algorithm 1, the four words carry, S, biA, and qiM must be summed. However, the 3-2 compressor can only receive 3 words, and accordingly, a problem arises in that the two main input words biA and qiM need to be summed in advance. Also, when the 3-2 compressor performs addition, it must receive carry, S, and one of the four words (namely, carry, S, biA, and qiM) and accordingly, requires a 4:1 multiplexer to select one of the four words.

Montgomery modular multiplier using a compressor and multiplication method


An apparatus for displaying system management information includes a combination storing unit that stores display pattern information that is obtained by combining, in subjective basis, system management information provided by a plurality of system management units; and a combination display unit that combines the system management information based on the display pattern stored in the combination storing unit, and displays the system management information combined.

1) Field of the Invention
The present invention relates to a method and apparatus for displaying system management information, a computer product for the same, and an operation management system, and more particularly, to a method and apparatus for displaying system management information, a computer product for the same, and an operation management system that can support a system manager to investigate a system when an error occurred, and provide a prompt settlement of the error.
2) Description of the Related Art
With a spread of a so-called open system, it is now popular to build an information processing system by combining hardware and software from a variety of vendors. In such a multi-vendor environment, a system manager is required to acquire a proficiency in operation systems uniquely provided by each of the hardware and the software, which is quite a big burden to the system manager.
To support the system manager to work in the multi-vendor environment, an operation management system has been developed, and is now widely in use, in which management of different hardware and software is performed in an integrated fashion using a unified system.
One of the significant functions of the operation management system is a message management function that collects a message to the system manager, which is output to a log and the like by the hardware or the software, and display the message on a monitor of an operation management terminal. With this function, the system manager can figure out an error occurred in all of the hardware and the software and a sign for the error with nothing other than observing the monitor of the operation management terminal.
A technology for such an operation management system is disclosed in, for example, Japanese Patent Application Laid Open Publication No. Hei-07-230424 and Japanese Patent No. 2000-207372.
However, the conventional operation management system has a drawback in supporting the system manager to work after recognizing an error occurred.
When an error or a sign for the error is displayed on the monitor of the operation management terminal, the system manager needs to perform an investigation to check a situation of the error occurrence and to figure out a reason of the error. Because the information collected by the operation management system is limited to basic information, the system manager must refer to information provided by the hardware or the software relating to the error to investigate details of the error. It is a difficult operation due to following two reasons.
The first reason is a difficult in selecting on object of the investigation. For example, when an error in an application response has occurred, it is necessary to check an operation status of the application by referring to a management display for management of the application, or to check a status of a central processing unit (CPU) or a memory by observing a management display for management of a server. At this moment, a kind of know-how is required to pick up information relating to the error from among various pieces of information provided by the hardware or the software in an appropriate manner.
The second reason is a difficult in accessing the object of the investigation. Even though the information to be investigated is successfully selected, the investigation is not possible without acquiring the information. As described earlier, because each of the hardware and the software has a unique management system, the system manager must obtain a mastery of a method of acquiring information according to each of the management systems.
If there is a missing in selecting the object of the investigation, or if there is a trouble in accessing the information on the object of the investigation, it becomes late to figure out a reason of the error, and as a result, it causes a delay in fixing up the error. A time-lag of the error may not only cause an inconvenience to a user, but also invite a loss of money. To avoid such a case, it is highly demanded for the operation management system to implement a function to support the system manager to work after recognizing an error occurred.

Method and apparatus for displaying system management information, computer product for the same, and operation management system


In another aspect the invention is a (drink bottle or container) closure assembly as a unit having                an occlusion region providing first component, the first component being adapted for a closing engagement with a complementary bottle or container, and having a liquid passageway to be open from the bottle or container to an outlet below at least part of the occlusion region,        as a second component, a spout or top with a dispensing outlet capable of being occluded by the occlusion region to provide a substantially liquid tight environment from an engaged liquid bearing bottle or container unless the second component rises from its dispensing outlet occluding condition, and        a third component, rotation of which controls the rise and fall of the second component relative to said occlusion region.

Drink bottles frequently have a pull out member of a closure assembly which separates components so as to allow a dispensing pathway for liquid from within a drink container to which the closure assembly has been fixed.
Many of such forms of assembly require a pulling out of a member.
The present invention envisages a dispensing closure assembly where a simple twisting of part of the assembly will open the dispensing pathway. It is an alternative or a further object of the present invention to provide such a dispensing closure assembly where a simple twisting closes such a dispensing pathway.


A method and apparatus for reducing lot to lot CD variation in semiconductor wafer processing feeds back information gathered during inspection of a wafer, such as after photoresist application, exposure and development, to upcoming lots that will be going through the photolithography process, and feeds forward information to adjust the next process the inspected wafer will undergo (e.g., the etch process). Embodiments include forming a feature such as an etch mask on a semiconductor wafer at a xe2x80x9cphoto cellxe2x80x9d by a photolithography process, then conventionally imaging the feature with a CD-SEM to measure its CD and other sensitive parameters. The measured parameters are linked, via the feature""s SEM waveform, to photolithography adjustable parameters such as stepper focus and exposure settings. If the measured parameters deviate from design dimensions, the linked information on focus and exposure is fed back to the photo cell so the stepper can be adjusted, either automatically or at the user""s discretion, to correct the deviation in following lots. The measured parameters are also linked to etch process adjustable parameters such as etch recipes for different over-etch and/or etch chemistry. If the measured parameters deviate from desired values, a linked etch recipe to correct the error is fed forward to the etcher and implemented automatically or at the user""s discretion. This feedback and feed-forward mechanism improves lot to lot CD control at inspection following photoresist development and at final inspection as well.

The present invention relates to a method and apparatus for monitoring and controlling processing carried out on a semiconductor substrate, and more particularly for controlling critical dimensions (CDs) of features formed on the semiconductor substrate through feedback and feed-forward of information gathered during in-process inspection of the features. The invention has particular applicability for in-line inspection of semiconductor wafers during manufacture of high-density semiconductor devices with submicron design features.
Current demands for high density and performance associated with ultra large scale integration require submicron features, increased transistor and circuit speeds and improved reliability. Such demands require formation of device features with high precision and uniformity, which in turn necessitates careful process monitoring, including frequent and detailed inspections of the devices while they are still in the form of semiconductor wafers.
One important process requiring careful inspection is photolithography, wherein masks are used to transfer circuitry patterns to semiconductor wafers. Typically, a series of such masks are employed in a preset sequence. Each photolithographic mask includes an intricate set of geometric patterns corresponding to the circuit components to be integrated onto the wafer. Each mask in the series is used to transfer its corresponding pattern onto a photosensitive layer (i.e., a photoresist layer) which has been previously coated on a layer, such as a polysilicon or metal layer, formed on the silicon wafer. The transfer of the mask pattern onto the photoresist layer is conventionally performed by an optical exposure tool such as a scanner or a stepper, which directs light or other radiation through the mask to expose the photoresist. The photoresist is thereafter developed to form a photoresist mask, and the underlying polysilicon or metal layer is selectively etched in accordance with the mask to form features such as lines or gates.
Fabrication of the mask follows a set of predetermined design rules set by processing and design limitations. These design rules define the space tolerance between devices and interconnecting lines and the width of the lines themselves, to ensure that the devices or lines do not overlap or interact with one another in undesirable ways. The design rule limitation is referred to as the critical dimension (xe2x80x9cCDxe2x80x9d), defined as the smallest width of a line or the smallest space between two lines permitted in the fabrication of the device. The CD for most ultra large scale integration applications is on the order of a fraction of a micron.
As design rules shrink and process windows (i.e., the margins for error in processing) become smaller, inspection and measurement of surface features"" CD, as well as their cross-sectional shape (xe2x80x9cprofilexe2x80x9d) are becoming increasingly important. Deviations of a feature""s CD and profile from design dimensions may adversely affect the performance of the finished semiconductor device. Furthermore, the measurement of a feature""s CD and profile may indicate processing problems, such as stepper defocusing or photoresist loss due to over-exposure.
Thus, CD and profile values, and the variation of feature CD from design dimensions, are important indicators of the accuracy and stability of the photoresist and etch processes, and xe2x80x9cCD controlxe2x80x9d to reduce such variation is an important part of semiconductor processing. CD control necessarily involves monitoring and adjusting both the photolithography and etch processes to address CD variations from field to field (FTF) within a wafer, from wafer to wafer (WTW) and from lot to lot (LTL). Among FTF, WTW and LTL variation, FTF and LTL are dominant variation components, while WTW typically counts for less than 10% of the total CD variation. FTF variation is generally determined by process tool performance, such as photoresist coating and baking uniformity, stepper or scanner stage leveling, and etch micro-loading uniformity. On the other hand, LTL variation is generally determined by process stability, including process equipment stability.
Because of the extremely small scale of current CD""s, the instrument of choice for measurement and inspection of surface features produced by photolithographic processing is a scanning electron microscope (SEM) known as a xe2x80x9ccritical dimension scanning electron microscopexe2x80x9d (CD-SEM). Although conventional SEM""s are useful for measuring CD""s, they generally do not provide immediate feedback to the photolithography process to reduce LTL variations, and the results of conventional inspections are not typically used to adjust subsequent etch processing. Furthermore, conventional CD-SEMs cannot provide an adequately detailed direct image or measurement of feature profiles. Still further, conventional methods of direct inspection of feature profiles are destructive to the sample under inspection, are time-consuming, or both.
There exists a need for a simple, cost-effective methodology for fast and meaningful identification and correction of lot to lot CD variation without significantly reducing production throughput.
An advantage of the present invention is the ability to reduce lot to lot CD variations in semiconductor wafers without reducing production throughput, by utilizing information gathered during in-process inspection of the wafers.
According to the present invention, the foregoing and other advantages are achieved in part by a method of controlling the processing of a semiconductor wafer, which method comprises performing a first process on the wafer and obtaining characteristics of a target feature on the wafer formed using the first process. A set of process parameter values for a second process is determined based on the target feature characteristics, and the second process is then performed on the wafer based on the second process parameter values. Additionally, a set of process parameter values is determined for the first process responsive to the target feature characteristics, and the first process is performed on another semiconductor wafer responsive to the first process parameter values.
Another aspect of the present invention is an apparatus for carrying out the steps of the above method.
A still further aspect of the present invention is a computer-readable medium bearing instructions for controlling the processing of a semiconductor wafer, the instructions, when executed, being arranged to cause one or more processors to perform the steps of the above method.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present invention. Accordingly; the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

Integrated critical dimension control for semiconductor device manufacturing


A system is disclosed for inhibiting the corrosion of ferrous and other metals by passivating the metals. The system includes novel buffered compositions which may be applied to metal products for preventing or retarding corrosion and methods for applying the buffered compositions to metal products such that corrosion protection of the products is achieved through passivation. The methods include an in-situ application to existing structures with metal reinforcement as well as applications to metal products during manufacture. Generally, the compositions may be in various forms and comprise a carrier component and one or more pH buffer components. The buffer is selected to retain the proximity of the metal at a pH at which the metal is passive to corrosion. The compositions are environmentally friendly and are capable of replacing chromates which have been traditionally used with zinc and zinc alloys to inhibit corrosion of metals but which are potentially harmful to the environment.

1. Field of the Invention
The present invention in a broad aspect relates to inhibiting the corrosion of metals. The invention more particularly concerns compositions and methods of controlling the pH proximate a point of incipient corrosion of a metal at a pH value where the metal is passive to corrosion. The invention more especially concerns coating compositions comprising one or more particulate or liquid materials, including one or more pH buffers. The compositions also preferably include one or more particulate or liquid corrosion inhibitors. The compositions also typically include a vehicle or other carrier for the particulate materials and liquid materials, which preferably takes different forms, depending on the nature and form of the metal being protected.
2. Related Art
The corrosion of steel and other metal products continues to be a serious technical problem which has profound effects on the economy and the standard of living. It causes premature replacement of infrastructure, which in turn causes loss of natural resources, and gives rise to inferior roads and buildings. It also causes premature replacement of equipment and parts in industry and in boats and other marine vehicles, automobiles, and aircraft.
The process of corrosion requires several physical conditions. These conditions include a metallic path, an electrolyte, anode, cathode, and a potential difference between the anode and the cathode (tendency to corrode). A metallic path allows the transfer of electrons between the anode and cathode sites; this path is normally the substrate metal. The electrolyte is normally an aqueous solution around the substrate metal and contains ionic species capable of transferring charge between the anode and the cathode of the substrate metal. The anode is the location where the substrate metal corrodes and mass loss occurs. At the anode, metal atoms lose electrons and convert to metal ions which are drawn into the surrounding electrolyte. At the cathode, ionic species receive electrons from the substrate metal and convert them back to molecular form. Potential difference (or tendency to corrode) between the anode and cathode can result from many different conditions which include: variations in metal or alloy compositions; difference in amount of dissolved oxygen; presence of impurities on the substrate; ionic strength and/or constituents; temperature differences; etc.
Corrosion can be prevented, halted, or reduced by interrupting the transfer of electrons, by changing the chemistry at the anode or cathode, or by isolating the substrate from the electrolyte. Methods to achieve the prevention of corrosion include the use of barrier coatings or claddings, sacrificial coatings, corrosion inhibitors, cathode protection, and surface passivation. The barrier coatings or claddings include paints, organic coatings, ceramic and inorganic coatings, plastics, noble metal platings or claddings (such as nickel) and more. Sacrificial coatings prevent corrosion by having a greater tendency to corrode than the metal they protect, thus converting the substrate metal to a more noble (non-corrosive) potential. Sacrificial coatings include zinc, aluminum, and magnesium metals and alloys applied as claddings, hot dip coatings, platings, or as fillers in primers and paints or other organic coatings. Corrosion inhibitors change the surface chemistry at the interface between the metal substrate and the electrolyte solution. This interface barrier may be formed by oxidizing the anode surface, precipitating a film or barrier layer that limits diffusion of ionic species between the bulk electrolyte and the substrate surface, or by adsorbing compounds which impart a hydrophobic film to the substrate metal surface. Cathodic protection of a substrate surface may be achieved by converting the entire surface of the substrate metal to a cathode through the use of sacrificial anodes or impressed electrical current. Surface passivation involves importing an oxide film to the substrate metal surface, thus preventing or reducing the tendency of the substrate metal to develop anode and cathode sites. Metallic substrates develop passive surfaces in specific environments or when exposed to solutions with specific pH ranges. For example, steel and iron substrates are naturally passive when exposed to aqueous solutions that have a pH of 8.5 or above. Aluminum also has a naturally passive surface due to an oxide that forms a tightly adherent oxide film limiting further exposure of oxygen to the metal substrate. Passive films, however, can be attacked and compromised by certain ionic species. In the case of iron and iron alloy materials, the naturally passive surface can be compromised by chloride ions and hydrogen ions, among others.
The previously mentioned mechanisms of corrosion protection have various drawbacks. Barrier coatings can be expensive and offer very little protection against corrosion if they are compromised, damaged mechanically, or have insufficient coverage. Sacrificial coatings have the potential of creating embrittlement of high strength steels due to the creation of monatomic hydrogen by-products from the corrosion reaction. The coatings may also be rapidly used up under certain accelerated corrosion conditions. Corrosion inhibitors are often expensive and some have been shown to be environmentally unfriendly or toxic. Many of these are available only as liquids making them inappropriate for certain applications as they function best in certain concentration ranges. Cathodic protection can be an expensive protection means that requires skilled professionals for its design and application. It is more readily applicable to new structures, but is difficult and/or expensive to install on an existing structure. Surface passivation has been used relatively little because it requires control of the environment around the substrate metal surface.
In nature, stable materials exist at their lowest form of energy. Iron typically exists as iron oxide ore. Mankind spends a tremendous amount of money refining and adding energy to the iron ore to create steel and other iron products with the necessary properties for fabrication of metal products and for construction of roads, bridges, buildings, and the like. The natural response of such products to the environment is to return to their lowest, most stable energy state, i.e., the iron oxide state. This corrosion process is accelerated when the products are exposed to corrosive constituents in the environment. Large amounts of time and money are expended annually in the use of coating materials to inhibit such corrosion.
Eight types of corrosion are defined by the National Society of Corrosion Engineers, namely: (1) General; (2) Localized; (3) Galvanic; (4) Environmental Cracking; (5) Erosion-Corrosion Cavitation and Fretting; (6) Intergranular; (7) Dealloying; and (8) High Temperature. General corrosion results from open exposure to corrosive conditions. Localized corrosion affects smaller portions of the metal surface than general corrosion but the rate of penetration may be very fast. Crevice corrosion is a form of localized corrosion resulting from corrosive exposure in a shielded location where oxygen depletion occurs. The oxygen depletion results in the development of acidic conditions which accelerate the corrosive loss of base metal. Electromotive corrosion is an accelerated form of localized corrosion due to stray electrical currents passing through an active corrosion cell.
General corrosion, crevice corrosion and electromotive corrosion are typically the kinds of corrosion of primary concern with iron and steel products. However, this invention is not only applicable in inhibiting those kinds of corrosion, but also in inhibiting other types of corrosion.
Galvanic corrosion occurs when two metals with different potentials or tendencies to corrode are in metal-to-metal contact. Fretting corrosion is wear or the damage that occurs at the interface of two contacting surfaces, at least one of which is metal, when they are subject to rubbing, i.e., minute slippage relative to each other. Intergranular corrosion is a selective or localized attack at or adjacent to grain boundaries without appreciable attack in the grain. Dealloying corrosion is a phenomenon associated with selective removal of one or more components from an alloy.
Crevice corrosion is a special form of corrosive action in that it typically may involve a bacterial or microbial attack accompanied by an environmental change in pH with anaerobic conditions. Microbes that promote corrosion of metals can be classed into five general groups: 1) acid producers which oxidize sulfur compounds to change sulfur compounds to sulfuric acid; 2) slime formers which aid in the production of anaerobic micro environments; 3) sulfate reducers that consume hydrogen and depolarize cathodic sites; 4) hydrogen feeders which feed on hydrocarbons; and 5) metal ion concentrators/oxidizers that work in conjunction with other microbes to create thick, bulky deposits to create concentration cells. Typically, more than one type of microbe is working at any one crevice corrosion site in a symbiotic relationship, fostering the growth of others. This form of attack is often hard to detect, since by definition initiation is often in the small crevices concealed in an anaerobic site. These sites often exhibit deep pitting, compromising the structural integrity of the base metals under attack.
Conditions that favor the promulgation of corrosive microbes include anaerobic environments, pH in the range of 0.5-10 (depending on the type of microorganism), and high concentrations of hydrocarbons upon which the microbes feed. Metal strands used in concrete structures can be ideal initiation sites. The strands used in such structures are typically of 1.times.7 high strength steel construction. Unfortunately, almost as soon as such a concrete structure is placed, cracking begins to occur. These cracks allow water and other corrosive materials to penetrate the structure and thereby compromise the integrity of the structure. The cracks become not only ideal crevice corrosion sites, but also places for potential physical degradation of a structure by alternating freeze and thaw cycles with the hydraulic force of water breaking up the concrete.
The current cable market for post tensioned and pretensioned pre-stressed concrete is dominated by bare steel 1.times.7 strand. Strand is available with a fusion bonded epoxy coating with the surface of the epoxy containing an optional aluminum oxide grit to promote bonding with concrete (ASTM Specification A882/A882M). In addition, 1.times.7 strand containing grease and covered with polyethylene is also available for specific applications. For bridge stays and tower supports, Conduits manufactured from plastic or steel materials such as galvanized steel or polyethylene are currently typically used as containment for individual strands or multiple bundles of strands. The conduits are commonly filled with grout to strengthen the assembly and to fill in the interstices. The alkaline nature of the grout passivates the surface of the steel from corrosion. Strand and wire rope for the automotive industry and other general purpose uses currently typically have a zinc or zinc alloy hot dip coating and may be covered with a number of thermoplastic coatings. The zinc or zinc alloy coatings protect the surface of the steel from corrosion galvanically due to its sacrificial nature (it corrodes preferentially to steel).
Organic plastic materials have also been used to fill the interstices between the wires on some cable products. Ceramic based, corrosion resistant coatings have been developed and are currently in use in automotive parking brake cable strand products. However, ceramic coatings are not usually suitable for wire rope products because the abrasiveness of such coatings reduces fatigue life of the wire rope.
The use of bare strand products causes problems when exposed to corrosive environments. The strand surface is not protected from corrosive constituents in the environment. Strand stored to be placed in casting beds (forms that are reused time and time again for making of structural elements of precast concrete) often show signs of initial red rust before being surrounded by the protective encasement of concrete. In the case of strand used as a prestressor for concrete materials, corrosion can occur when corrosive constituents such as salts from deicing compounds, admixtures to the concrete, or marine environment migrate to the surface of the strand. Initially, the pH in concrete is near 12.0. Corrosiveness increases as the concrete pH drops or when carbonation occurs. Due to the chemical reactions incurred during the cure cycle of the concrete mixture, there are zones of cure that striate and promote cracking at the surface of the curing mixture. Depending upon the cure conditions, the types of admixtures and aggregates, and the surrounding physical conditions, this cracking may or may not be readily visible to the naked eye. The expansive forces caused by the development of corrosion on the steel strand or other steel reinforcement can also crack the concrete. Whatever their origin, cracks can accelerate the degradation of the concrete and also the degradation of prestressing strand (by exposing the steel), necessitating repair or replacement of the concrete member to avoid failure of the structure. Bare strand has no protection against corrosion except for the surrounding concrete. Rehabilitation projects often use sealers on cracked concrete to lessen the chance that water or other corrosive elements will enter the cracks and accelerate the degradation process. Typically these sealers only provide a physical barrier and do not address the underlying steel components that are the subject of the corrosive attack.
Epoxy coated strand, the only current commercial alternative to bare strand for pretension prestressing applications, has a number of limitations. The epoxy coating effectively offers only barrier protection against corrosive constituents. When the barrier has been compromised due to coating imperfections or field handling, corrosive constituents can get to the strand wires and cause local corrosion to develop. The corrosive constituents can then migrate beneath the epoxy coating, developing crevice corrosion cells and cause delamination of the epoxy coating from the surface of the strand wires. Crevice corrosion can cause rapid failure of strand wires as well as a reduction of the pH in the corrosion cell area. The epoxy coating has good overall chemical resistance, but can be attacked by oxidizing materials such as chlorine, fluorine, and hypochlorite materials. Sodium hypochlorite is commonly used as a water treatment additive and for bleaching in the pulp and paper industries. The hypochlorite ion may also be formed in alkaline environments (such as concrete) when chloride ions or chlorine is present.
Construction of precast members using epoxy coated strand requires the use of special jaws on the strand during the tensioning process. Even with the special jaws, slippage sometimes occurs, causing removal of the epoxy coating and adding difficulty to the construction of the precast members. Jaws that are typically reused 60-70 times for bare strand often require cleaning after only two or three uses with epoxy coated strand.
It is common practice for post tension cables to be encased with hydrocarbon greases and sheathed with a polymeric coating that excludes oxygen. Strand and wire rope products filled with grease are typically limited to applications where high bond strength is not required (post tension applications) and bridges. Grease has been shown to offer good corrosion protection when present in excess; however, bare areas can occur due to rubbing. Greases may be expelled during periods of high temperatures, and many oils and greases become acidic with the passage of time, increasing the threat of corrosion. This acidic condition speeds the ionic exchange between the surrounding electrolyte and the metal substrate. The grouting of strand tendons can lead to air pockets or voids between the tendons where corrosive materials can collect. Some admixtures commonly used in grout formulations are corrosive with respect to steel reinforcement.
The interstices between the individual wires that form cables or strands frequently show the first place of attack. A paper in 1985 described the process of a bio-film community as follows: (1) iron-oxidizing bacteria infiltrate metal surfaces and put down "roots" to anchor a community; (2) slime formers and fungi are attracted to this site because of the nutrient availability and/or protection; (3) sulfate reducing bacteria thrive in this anaerobic layer producing copious amounts of corrosive hydrogen sulfide gas; (4) a layered aerobic/anaerobic stratification forms typically with the first layer of bio-film protecting an underlying anaerobic community.
Electromotive corrosion, like crevice corrosion, is also an accelerated form of corrosion which may be due to stray electrical currents from nearby cathodic protection systems or power cables, or to static electrical currents generated from frictional contact, as for example, between automobile tires and driving surfaces as well as gear and bearing friction (and subsequently discharged through the automotive parking brake cables).
Many different types of corrosive environments exist: Marine, Rust Belt, Water Treatment Facilities, Power Plants, Pulp and Paper Mills, and Chemical Process Plants. Natural corrosives such as salts from marine environments, and man-made corrosives such as acid pollutants, corrode infrastructures and metal products. Structures requiring protection from corrosive constituents include roads, bridges, dams, parking garages, and piers. In that regard, people everywhere are increasing demands for snow and ice free roads, bridges, and parking garages through the use of deicing salts; unfortunately, these salts further contribute to the deterioration of infrastructure. Metal products requiring protection from corrosion constituents include metal parts of boats and marine equipment, automobiles and aircraft.
Considerable effort has been expended by the construction and automobile industries, among others, to delay and reduce the rate of corrosion of steel. Such corrosion can result in failure not only of the steel, but also the elements and structures the steel supports. For example, corrosion of reinforcing steel members in concrete is known to result in deterioration of the concrete. Such deterioration is believed to be due in large part to the fact that the corrosion products tend to occupy a greater volume of space than the original steel, resulting in stresses on the surrounding concrete material. Structural distress may also occur due to a reduced cross-sectional area of the steel or to a loss of bond between the steel and the concrete.
In industrial applications, metal corrosion can be accelerated by several factors such as the infiltration of oxygen and moisture ("general corrosion") and the presence of stray electrical currents ("electromotive corrosion"). Metal corrosion can also be accelerated by bacterial attack in highly acidic (i.e., pH<2.0), anaerobic environments on the metal surface ("microbiological induced corrosion").
One well-known method for preventing steel corrosion is galvanization. In particular, zinc and zinc alloys together with thermoplastic coverings are commonly used to coat strands and wire rope in many industries. Zinc and its alloys are known to protect the surface of steel sacrificially, in that zinc corrodes preferentially to steel. However, a major disadvantage of this treatment is that the zinc coating provides only temporary protection of the base metal. Also, the coating may corrode unevenly, jeopardizing the integrity of the underlying metal. Zinc electroplating processes used to galvanize ferrous substrates often lead to hydrogen embrittlement of steel products, notably the high strength, highly stressed steels. In addition, the corrosion of any galvanic zinc coating (electroplate, mechanical plate, cladding, thermal spray, hot dip, or zinc filled coating) can cause hydrogen embrittlement of high strength, highly stressed steels such as reinforcing strand used in concrete and bridge stays.
For the above reasons, many industries have begun to investigate alternative corrosion treatments. For example, most such treatments which have been developed for wire products involve coating or encapsulating the base metal with various compounds such as plastics, ceramics, epoxy resins, greases, and other hydrocarbon-based substances. These substances may be applied either on the outside of the wire ropes or strands or in the interstices of the ropes or strands. However, these treatments only provide a physical barrier to corrosive elements such as moisture and oxygen, and they do not address the corrosion of the steel itself. Furthermore, even with such applications, the steel is still vulnerable to crevice corrosion, since highly acidic, anaerobic environments will often appear on the metal surface, thereby promoting bacterial attack.
Current industry standards for corrosion prevention center around the use of heavy metals (chromium, nickel, lead, cadmium, copper, mercury, barium, etc.) or heavy metal compounds to passivate or provide a barrier to inhibit, or galvanically sacrifice, and thereby protect the substrate metal beneath. The introduction of these materials into the environment, however, can lead to serious health consequences as well as substantial costs to contain or separate the materials or clean up environmental contamination. Dealing with corrosion, accordingly, is a continuing problem and better systems for preventing corrosion are still needed.

Corrosion resistant buffer system for metal products


An improved sprocket profile for engaging a roller or bush chain smoothly and preventing radial impact with the root of the tooth during engagement. Contact between the sprocket teeth and the roller chain is altered by providing teeth with a root radius equivalent to that of the chain engaging component, with the center point of the root radius located one chordal distance inside the sprocket's pitch circle. This profile allows chain rollers or bushings to impact sprocket teeth tangentially on their flanks rather than radially on their tooth root.

1. Field of the Invention
The invention pertains to the field of sprockets for roller or bush chains. More particularly, the invention pertains to a sprocket that reduces the noise generated when the roller or bush chain and the sprocket mesh.
2. Description of Related Art
Conventional chain sprocket interfaces seat the roller or bush in the root of the sprocket tooth as if the sprocket is held stationary and a taut chain is wrapped around it. A roller swinging-on an arc the length of a chain pitch around the center of the previous roller, located on the pitch circle of the sprocket, contacts the root of the sprocket tooth when reaching the pitch circle of the sprocket.
FIG. 11 shows a chain C having rollers R engaging sprockets S1 and S2. Noise generated by a roller chain meshing with a sprocket is a long recognized problem. One of the most significant sources of noise in a typical roller chain drive results from the repeated impacts between the rollers and the sprockets as the rollers seat between the teeth of the sprocket. As shown in FIG. 12, a roller 10 engaging a sprocket S swings on an arc 20 having a radius equal to the chain pitch P around the center of a seated adjacent roller 30. The roller 10 swings along the arc to make a substantially radial impact with the sprocket tooth root 40.
The prior art discloses attempts to reduce the noise created by rollers impacting a sprocket. Some sprocket designs have attempted to decrease the impact noise of roller chain drives by altering the sprocket tooth profile. One attempt to reduce roller chain and sprocket noise using a modified sprocket tooth profile is described by U.S. Pat. No. 5,921,877. A sprocket tooth profile having three sections is described as making the roller of a chain come into engagement with the teeth of the sprocket without generating a large noise. However, this design is limited to a unidirectional roller chain drive because of the asymmetry of the tooth profile as generally shown by FIG. 13.
Other designs also utilized an asymmetrical tooth design in an effort to reduce the noise generated by the impact of the rollers as they strike the sprocket. U.S. Pat. Nos. 5,921,878 and 5,993,344 disclose an asymmetrical tooth profile that incorporates a flank flat that is tangential to an engaging flank radius and a first root radius, and a pitch mismatch, where the sprocket chordal pitch is less than the chain chordal pitch. This arrangement is described as facilitating a staged roller tooth contact with the sprocket. Again, the asymmetry of the tooth profile mandates a unidirectional roller chain drive system.
Other asymmetrical tooth designs provide a tooth space clearance between the roller and a portion of the tooth root in an attempt to reduce the noise generated by the vibrational contact of unseated rollers with the sprocket teeth as the rollers wear. FIG. 14 illustrates one such design. Instead of impacting the bottom of the tooth root, the roller makes radial contact with the flanks of adjacent teeth at locations A1 and A2 while bridging over the bottom of the tooth root. This sprocket is also designed for a unidirectional roller chain drive system. Similarly, U.S. Pat. No. 5,397,278 simply reduces the gap between adjacent sprocket teeth, such that the roller makes simultaneous radial contact with the flanks of adjacent teeth. However, this design may be used in a multi-directional roller chain drive system.
U.S. Pat. No. 6,736,744 discloses a sprocket that substantially avoids radial impact of chain rollers with the sprocket. The tooth root radius of the sprocket is increased while the sprocket pitch circle diameter is maintained. Thus, a clearance between the roller and the tooth root is created, which allows rollers of a chain of like pitch to impact the sprocket teeth in a substantially tangential fashion on their flanks, rather than substantially radially on the tooth root. Backlash is not minimized with this design.
Similarly, U.S. Publication No. 2003/0186766 discloses an engaging flank profile with seating, impact and distal portions, all with arcs with well-defined radii and arc centers. The profile of the disengaging flank is determined in accordance with a modified form of the JIS standard, in which the sprocket pitch is smaller than the roller chain pitch. The impact point is located at the tangent point to permit a gradual change in the roller velocity. Backlash is not minimized with this design.
Therefore, there is a need in the art for a multi-directional sprocket that substantially minimizes the noise generated by the substantially radial impacts between the rollers of a roller chain and a sprocket, while minimizing backlash.

Sprocket tooth profile for a roller or bush chain