A porous iron system metal bond diamond grinder using diamond as grinding particles and iron system metal powder as binder so as to have a large number of pores in the binder. The grinding particles are chemically and physically combined with the iron system metal to be held. The occupancy rate of pores in the whole grinder is 5 to 60%. The iron system metal is selected from a group composed of mixtures of iron powder, carbon-coated iron powder, iron nitride powder, carbon and iron. Carbon of diamond constituting the grinding particles is reacted to the iron system metal in the surface. In the manufacturing method, grinding particles and binder are mixed and molded into a predetermined shape and the molded product is then heated and sintered at 900.degree. to 1150.degree. C. The occupancy rate of pores and/or the concentration gradient of diamond are adjusted. The porous iron system metal bond diamond grinder capable of performing grinding continuously for a long time without loading can be provided.

1. Field of the Invention
The present invention relates to a porous metal bond grinder or whetstone used to grind various materials and a method of manufacturing the grinder. More particularly, the porous grinder of the present invention has an increased occupancy rate of pores so that the grinding function by grinding particles is enhanced to improve the grinding quality thereof.
2. Prior Art
A grinder is used to grind various works. A grinder used for grinding is composed of grinding particles and binder and has innumerable pores formed therein. The grinding particles function as edges for cutting or grinding various works, and the binder functions as a support for combining the grinding particles with each other. Further, a large number of continuous pores function as chip pockets for discharging chips cut off by grinding particles.
Recently, various devices or apparatuses often use material such as ceramics, cemented carbide or hard metal or superspeed steel which is difficult to grind. Accordingly, the need for grinding a material of this type has increased more and more. As a grinder or a grinding wheel for grinding a material of this type, one using super grinding particles such as diamond grinding particles or boron nitride grinding particles of the cubic system is being gradually used.
As a grinder using such super grinding particles, there are various kinds of grinders such as a vitrified bond system, a resinoid bond system, a metal bond system, a silicate bond system and a rubber bond system in accordance with the kinds of the binder. These grinders have both merits and demerits, while the grinder of the metal bond system using metal and its alloy as the binder thereof is mainly used in view of its strength and long life.
The grinder of the metal bond system is manufactured by putting metal powder having grinding particles scattered uniformly into a mold together with a metal base and subjecting it to pressing and sintering (or hot pressing) processes. The binder of metal used in the metal bond grinder uses, for example, a Cu-Sn system, a Cu-Sn-Co system, a Cu-Sn-Fe-Co system, a Cu-Sn-Ni system or a Cu-Sn-Fe-Ni system or any of these systems to which phosphorus (P) is added.
The grinding particles of a conventional metal bond grinder has an extremely strong combination or binding strength as compared with the resinoid bond grinder and the vitrified bond grinder. Accordingly, the metal bond grinder can advantageously exert a sufficient retention force required to perform strong grinding by means of super grinding particles. However, the metal binder does not have sufficiently large pores to help discharge chips that are cut off by the grinding particles. Thus, "escape bores" in which chips enter are restricted to minute gaps between the metal bond grinder and a work or to minute gaps constituted by portions in the metal bond grinder in which grinding particles have fallen off. Further, in the metal bond grinder, the binding force of the grinding particles is extremely strong and accordingly when the grinding particles are worn, the worn particles have difficulty falling off from the binder. Hence, it is also difficult to form the "escape bores" that are formed by the grinding particles that have fallen off.
As described above, in the conventional metal bond grinder, the discharging of chips is deteriorated and loading occurs easily. Accordingly, the grinding resistance increases and the grinding quality deteriorates, so that the heat generated is increased. Further, the grinder has a tendency to unsuccessfully finish the surface of a work. Accordingly, it is very difficult to increase the contact area of the grinder and the work and perform grinding with higher efficiency.
In addition, the conventional metal bond grinder has a low sintering temperature and is hence apt to be softened at a low temperature. Accordingly, there is a defect in that plastic deformation occurs due to the heat generated upon grinding and the loading takes place in the surface of the grinder.
In order to eliminate the above defects, for example, Japanese Patent Application Laid-Open No. 59(1984)-182064 discloses a continuous porous metal bond grinder. However, this metal bond grinder does not utilize the powder sintering method. More particularly, in the manufacturing method of this metal bond grinder, an inorganic compound that is melted by solvent is sintered into a desired shape. Thereafter, gaps or spaces of the sintered body are filled with grinding particles and the body having spaces filled with grinding particles is heated. Then, melted metal or alloy is pressed into the spaces of the thus sintered body filled with the grinding particles and is then solidified. Thereafter, the inorganic compound is liquated out by a solvent.
Further, Japanese Patent Application Publication No. 54(1979)-31727 discloses a grinder that has many layers of metal coatings formed thereon and is sintered so as to be structured like a vitrified bond by hot press and has pores. In addition to this, various measures for preventing reduction in grinding quality have been proposed.
Furthermore, Japanese Patent Application Laid-Open No. 3(1991)-264263 discloses a grinder using cast iron for the purpose of preventing loading of the grinder. The grinder using the cast iron as a bond advantageously has great strength and high rigidity and is worn in the brittle fracture manner without the occurrence of plastic deformation, so that loading is less likely to occur. However, the bond of this grinder is too strong and accordingly the dressing property is deteriorated as compared with the bond of the copper system.
By forming a large number of pores within the grinder, grinding liquid can be impregnated into the pores to enhance the cooling characteristics of the grinder and a large number of chip pockets can be formed in the grinding surface to improve the discharging characteristics of chips. Further, the grinding resistance can be made small by the pores to improve the grinding quality. In other words, it can be expected that less heat is generated and the surface of a work is finished with high quality. However, when a large number of pores are formed in the conventional copper system metal bond grinder, the strength and the retention force of grinding particles thereof are naturally reduced, so that the sufficient grinding performance cannot be obtained.
Further, in the grinder using non-porous cast iron as the bond, iron powder is added to cast iron powder because of the inferiority of the sintering characteristics of the cast iron powder and then pressurized with the load of 8,000 kgf/cm.sup.2 to 1,000 kgf/cm.sup.2. By adding the iron powder, the original brittle fracture characteristic of the cast iron is lost and plastic deformation is apt to occur due to heat generated upon grinding in the same manner as the copper system bond, so that the characteristics of the cast iron cannot be drawn out sufficiently.

Porous metal bond grinder and method of manufacturing the same


The invention provides a reproducible, objective quantification technique that reliably segments white matter structures. The technique receives a seed voxel within the white matter structure from an individual, determines thresholds and selection criteria, creates a binary mask based on the at least one threshold and the at least one selection criteria and calculates the boundary of the white matter structure based on the binary mask. A magnification factor is applied to each component of the eigenvectors of voxels. Boundary voxels are determined wherein each of the boundary voxels has a magnitude above a predetermined value and is located next to a voxel having a magnitude below the predetermined value. A vector is drawn from the seed voxel to a boundary voxel and the boundary voxels are connected together, thereby forming the region of interest within the connected boundary voxels.

Diffusion tensor magnetic resonance imaging (DTI) facilitates provides the ability to quantitatively assess white matter integrity. One area where DTI has been used has resulted in the expansion of the boundaries of diagnostic imaging by examining the diffusion of water in brain tissue. Recent studies have shown DTI can be used to provide diagnosis of disease conditions in cerebral ischemia, acute stroke, and multiple sclerosis. Its diagnostic value is based primarily on restricted water movement due to myelin found in white matter. The restricted water movement causes anisotropic diffusion. The degree of directionality of the flow is termed anisotropy, which is the coefficient of variation of the eigenvalues of the diffusion tensor. Fractional anisotropy (FA) has been implicated to being sensitive to changes in white matter integrity. FA loss and apparent diffusion coefficient (Dav) rise have been demonstrated in a number of traumatic brain injury studies. It is natural to assume that these quantitative characteristics are indicative of white matter damage in a variety of pathologies.
The quantification of DTI for investigating white matter abnormalities is generally approached using one of two methods. These methods are voxel-based analysis (VBA) where data sets are compared at a voxel by voxel scale and region of interest (ROI) analysis. In cases where it is impractical to predict anatomical domains of damage, researchers tend to use a voxel-based approach to characterize statistical differences between groups. VBA involves spatial normalization of brain images to a stereotactic 3D space. In order to produce a more normalized distribution of image data, a smoothing function is applied to the images. Statistical differences between groups are then made on a voxel by voxel basis to determine variations in tissue composition.
While a voxel based strategy has the advantage of evaluating the brain in a model-free manner, and is therefore suitable for the identification of unexpected areas of white matter pathology, there are several limitations. A central disadvantage of this approach is that differences in gross anatomical morphology among subjects may influence spatial normalization and thus artificially inflate measurement differences. Moreover, many normalization algorithms use smoothing functions which introduce "blur" into the image, and violates the original uniformity of voxel size present in the original images, thereby creating noise in the measurement. Researchers have suggested the possibility that VBA has reduced and inconsistent sensitivity in specific regions of the brain, especially those with greater anatomical variability. Furthermore, VBA is only applicable for group analyses so its clinical application for individual subject analysis has not yet been convincingly demonstrated. Most importantly, VBA is not a genuine quantitative analysis of tissue differences, but a more qualitative analysis of regional variations.
Most researchers use ROI analysis when it is possible to hypothesize specific areas of the brain that are implicated in disease. However, ROI analysis normally requires manual tracing readily identifiable regions. Current methods for obtaining these boundaries are principally manual and subjective. These methods include hand drawn ROI analysis where investigators draw polygons over one of many potential 2 dimensional MR images. Manual tracing of white matter structures in the brain also is very time consuming, requiring expert contribution to accurately identify structure boundaries. The manual tracing can take up to several hours per case. For ROI analysis, researchers identify brain regions and compare FA and Dav between research subjects and normal controls. Selection bias and variability in the process of selecting images and drawing ROI's introduces significant barriers to both research methodology and clinical assessment. Conventional clinical analysis does not include a standardized quantitative protocol that can be applied to a variety of conditions.
From the above, it can be seen that there is a need for a rapid automated or semi-automated method for white matter quantification for both individual and group analysis.

Reproducible objective quantification method to segment white matter structures


A gear is made of resin and includes: a support cylindrical portion; a teeth-formed cylindrical portion arranged coaxially with the support cylindrical portion on a radially outer side of the support cylindrical portion and formed with a plurality of teeth in its outer periphery; and a web connecting an outer peripheral surface of the support cylindrical portion and an inner circumferential surface of the teeth-formed cylindrical portion, and an axial thickness of at least a part of the web becomes thinner gradually from the outer peripheral surface of the support cylindrical portion to the inner circumferential surface of the teeth-formed cylindrical portion.

1. Field of the Invention
The present invention relates to a gear, and image forming apparatuses such as an electrostatic copying machine, a printer, a facsimile machine, and the like provided with the gear.
2. Description of the Related Art
Japanese Patent No. 3666978 discloses a gear including: an outer peripheral portion having a cylindrical shape and provided with teeth; a rotation support portion having a cylindrical shape; an annular rib provided between the outer peripheral portion and the rotation support portion; an arm connecting the rotation support portion and the annular rib; an arm connecting the annular rib and the outer peripheral portion; first radial ribs connecting the rotation support portion and the annular rib; and second radial ribs connecting the annular rib and the outer peripheral portion. The arm connecting the rotation support portion and the annular rib is named as "first arm", and the arm connecting the annular rib and the outer peripheral portion is named as "second arm".
In the gear disclosed in Japanese Patent No. 3666978, each of the first and second arms is so formed as to have a plate-like shape which is perpendicular to a center of the gear, and a thickness in an axial direction of each arm is constant. However, an axial thickness of the second arm is thinner than an axial thickness of the first arm. Further, a circumferential thickness of each of the first and second radial ribs is constant. However, a circumferential thickness of the each second radial rib is thinner than a circumferential thickness of each first radial rib.
In such configuration, when a radial distance between the annular rib and the cylindrical outer peripheral portion is short, radial lengths of the second arm and the radial ribs become short. Accordingly, it is possible to improve a strength of the gear while maintaining a teeth surface accuracy i.e. a gear accuracy. However, when the radial distance between the annular rib and the cylindrical outer peripheral portion is long, radial lengths of the second arm and the second radial ribs become long. Accordingly, it is likely that a support strength of the teeth, which is strength of a gear in extended meaning, may be lacked. Further, in this case, repletion of synthetic resin to a forming die at a time of performing an injection molding to form the gear with synthetic resin may become worse, so that a defective molding may occur and a yield rate may be lowered. Further, in an image forming apparatus using such gear lacking strength for driving a rotating member, vibrations due to the defect in meshing of gears and unevenness in rotation may occur, so that an image quality may be impaired. Such problem may occur in a gear having neither an annular rib nor a radial rib.

Gear, and image forming apparatus provided with the same


A stent is disclosed which comprises generally of ring having, in the preferred embodiment, crossties that have flexibility by having at least one bend. The rings themselves have predetermined stress-relieving points to predispose, by stress relief, particular segments of each ring to bend upon application of an expansion force such as by a balloon or by other means. In the preferred embodiment, the individual rings have notches, reducing the cross-sectional areas at particular locations adjacent reversing bends such that upon radial expansion, bending occurs at these reduced cross-sectional areas to prevent stress from accumulating at the reversing bends.

Vascular stents are structures that are designed to maintain the patency of a vessel in the body. The stent provides internal support to allow the circulation to proceed therethrough. Stents can be used in the vascular system in ureters, bile ducts, esophagus, and in many other tubular structures in the human body.
Stents can be tubular or can be made from wire. Stents are typically made from a metal or polymeric substance or a metal coated with polymers which are biocompatible or contain heparin to reduce blood clotting or other tissue reactions. Many prior designs have used a coil approach where a wire is helically wound on a mandrel. Yet other designs have evolved--braided wire mesh and angulated wire forms wrapped on a spindle to form a coil.
U.S. Pat. No. 5,292,331 by Boneau and U.S. Pat. No. 5,403,341 describe such wire forms. These devices have very poor radial support to withstand the hoop strengths of the artery or vein and further are not suitable for arteries that are bent or curved or for long lesions; multiple stents are required. These designs do not provide any support to hold the wall of the artery, other than the memory of the metal.
Wall Stent, produced by Pfizer Inc., is a braided wire tube. Although this stent is flexible so as to be placed in curved arteries or veins and other body cavities, it does not have any radial strength imparted to it by design.
Wiktor, U.S. Pat. No. 4,649,922; 4,886,062; 4,969,458; and 5,133,732 describe a wire form stent. He describes stents made of wire helix made of a preformed wire which is in the sinusoidal form, in which either all or some of the adjacent strands are connected.
Arthus Fontaine, U.S. Pat. No. 5,370,683, also describes a similar device where a flat wire form of sinusoidal shape is wound on a mandrel to form a helical coil. the wire bends are "U" shaped and are connected to alternate "U"-shaped bands.
Allen Tower, U.S. Pat. Nos. 5,217,483 and 5,389,106 describes a similar device where the wire is preformed to a sinusoidal shape and subsequently wound on a mandrel to form a helical coil.
All of the above-described art fails to provide radial support. The pre-shaped wire form (sinusoidal in most of the prior art) is wrapped on a mandrel to form a coil. However, the forces imported by the vessel wall's hoop strength are radially inward. In other words, the force is acting perpendicular to the plane of the U-shaped wire form. This means that the bends that are in the wire add no structural strength to the wire form to support the force produced by the wall, which is radially inward.
When we examine the simple coils, such as taught in Scott U.S. Pat. No. 5,383,928 or Gene Samson U.S. Pat. No. 5,370,691 or Rolando Gills U.S. Pat. No. 5,222,969, it is apparent that the spring coil will withstand substantial radial forces due to the vessel wall; however, all these stents are bulky in their pre-expanded form and are hard to place in small and curved arteries or veins of the body. Also, a major disadvantage of this design is that when the coil stent is placed in a curved artery or vein, it forms an "accordion" shape whereby some strands in the outer radius are spread and those of the inner radius are gathered. Spring coils can also "flip" to form a flat structure when a longitudinal force is applied on one side of the stent.
The other types of stents that have been developed are tube stents. Palmer, U.S. Pat. No. 4,733,665; 4,739,762; 7,776,337; and 4,793,348 describe such a tube stent of slotted metal tube. The slotted metal tube is expanded by a high-pressure balloon to implant the stent into the inside wall of the artery or vein.
Joseph Weinstein, U.S. Pat. No. 5,213,561 describes a similar stent made of tubular materials with slots cut into it. On expansion using a balloon, it forms a structure with diamond-shaped slots.
Henry Wall, U.S. Pat. No. 5,266,073 also describes a stent, tubular, that has slots machined into it. When expanded, the edges of the stent lock to form a cylinder. Not only is this device stiff and can only be used for short lesions, but also the diameter cannot be adjusted to meet the exact needs of the particular vessel but it is fixed to the predetermined sizes.
Lau and Hastigan, U.S. Pat. No. 5,344,426 describes a slotted tubular stent that has a structure similar to Henry Wall's but has provided prongs that will lock in as the stent is expanded.
Michael Marin, U.S. Pat. No. 5,397,355 also describes a tubular slotted stent with locking prongs.
U.S. Pat. No. 5,443,500 illustrates the use of square openings with rectangular prongs that stick therethrough to lock the stent. This design, as well as other locking mechanisms, generally have resulted in very stiff stents because of the use of a tubular-type grid construction. Further, the locking devices have resulted in sharp outwardly oriented tabs which are used for the locking, which could cause vascular damage.
All the above-described tube stents, although typically providing substantial radial support when expanded, are not flexible enough to be placed in curved vessels. Arteries and veins in the human body are mostly curved and are tapered. As such, these tube stents suffer from this main disadvantage.
European patent document 042172982 employs wires that are doubled up and whose ends are snipped off to make a given joint. Such doubling up at the junction of two elements with snipped off free ends creates a potential puncture problem upon radial expansion. The sheer bulk of the doubled up wires makes them rotate radially outwardly away from the longitudinal centerline of the stent, while the plain ends on such an arrangement which are snipped off offer the potential of sharp points which can puncture or damage the intima. On the other hand, the apparatus of the present invention, employing sharp angles, as defined, avoids this problem in an embodiment which illustrates a continuous wire or wire-like member bent into a sharp angle. This type of structure alleviates the concerns of sharp edges, as well as the tendency of a doubled up heavy joint to rotate outwardly toward the intima upon radial expansion of the stem, as would be expected in the EPO reference 042172982.
Often these stents are layered with polymeric sheaths that are impregnated with biocompatible substances or can be coated with heparin or hydrogel. Most sheath-type coatings reduce endothelial cell growth through the stent, which is a major requirement in successful stenting of body cavities such as arteries and veins.
Several parameters in design of stents are important. Of the more important parameters is the issue of recoil. Recoil deals with the memory of the stent material which, generally speaking, upon expansion in the blood vessel will want to recoil back to its original shape. This can be problematic because it is desirable for the stent, once expanded, to remain in good contact with the vessel wall to avoid longitudinal shifting. Furthermore, any recoil constricts the flow passage and presents a greater portion of the stent in the blood flowpath, thus creating additional complications due to the turbulence which ensues.
Related to the concern regarding recoil is another concern regarding component twist. This phenomenon generally occurs when the cross-sectional area of the components is rectangular, such as when the stent is manufactured from a cylindrical piece which is then cut by lasers or other means to form the particular pattern. Particularly in the honeycombed designs involving the use of square or rectangular element cross-sections, radial expansion of such stents generally results in a twist of the component segments such that they extend into the flowpath in the artery or vein. Again, this causes turbulence which is undesirable.
Related to the problem of recoil or constriction after expansion is the ability of the stent to anchor itself in the vascular wall. An anchoring system that does not cause trauma is a desirable feature not found in the prior art.
Yet other considerations which are desirable in a stent not found in the prior art is the flexibility to be maneuvered around bends in the vascular system, coupled with the ability to conform to a bend without kinking or leaving large open areas. The stents of the present invention have the objective of addressing the issue of recoil, as well as providing an anchoring mechanism to fixate the stent once set. Several of the designs incorporate flexibility to allow the stent to follow a bend or curve in a vascular flowpath while a the same time providing sufficient radial deformation to ensure proper fixation while minimizing angular twisting movements of the stent components to minimize turbulence through the stent.
In a recent article appearing in late 1995, by Dr. Donald S. Baim, entitled "New Stent Designs," a description is given of the ideal endovascular prosthesis. There, Dr. Baim indicates that the ideal stent should have low implantation profile with enhanced flexibility to facilitate delivery. He goes on to say that the stent should be constructed from a noncorrosive, nonthrombogenic radiopaque alloy and have expanded geometry which maximizes radial strength to resist vascular recoil. The ideal stent described by Baim is further described as having a wide range of diameters and lengths. Dr. Baim concludes that it is unlikely that any current designs satisfy all these requirements. Thus, one of the objectives of the present invention is to go further than the prior designs in satisfying the criteria for the ideal designs as set forth by Dr. Baim in his recent article.


A sling chair having side rails which connect to a cross member spanning the side rails. Each side rail has an extension bearing a socket which accepts insertion of one end of the cross member. The chair has a fabric seating member retained conventionally to the side rails. The cross member and side rails provide both a structural frame for the sling chair as well as a frame for the fabric seating member. The novel construction reduces the traditional redundant separate chair and sling frames to one frame.

1. Field of the Invention
The present invention relates to sling chairs, and more particularly to a sling chair wherein the side rails are adapted to attach to a cross member spanning both side rails. This eliminates the need for separate chair and web frames.
2. Description of the Prior Art
Informal outdoor furniture, particularly of the type intended for use on decks and patios, has become quite popular. Manufactures of such furniture are called upon to offer practical, comfortable products to the consumer. Because outdoor furniture is subjected to the weather, it is not feasible to employ cushions to attain desired comfort. Cushions are subject to retaining water from rain and dew, dust, pollen, and other contaminants, and to become malodorous and discolored as a consequence.
To avoid reliance upon cushions, the prior art has developed furniture such as a chair, on which a supporting web is suspended on a frame which is in turn suspended on a frame of the chair. The sling frame is removable from the chair, which is known as a sling chair. This construction arose since it is easier and less expensive to construct the sling and chair frame separately. Examples of sling chairs are seen in U.S. Pat. Nos. 5,716,101, issued to Richard D. Frinier et al. On Feb. 10, 1998, and 5,911,478, issued to Lloyd Goodman on Jun. 15, 1999. These prior art sling chairs lack a side rail adapted to receive and retain a cross member spanning both side rails, while also retaining a fabric seating member, as seen in the present invention. Other chair designs include those shown in U.S. Pat. Nos. 4,234,226, issued to Donald B. Colby on Nov. 18, 1980, and 5,094,507 and 5,224,760, both issued to Terence Gibbs respectively on Mar. 10, 1992. These prior art sling chairs lack side rails adapted to receive and retain a cross member spanning both side rails, while also retaining a fabric seating member, as seen in the present invention.
Prior art conventional sling chair construction arose since it is easier and less expensive to construct the sling and chair frame separately. However, it is apparent that conventional construction of sling chairs entails costly duplication. There remains a need to simplify construction of sling chairs, in particular, to eliminate duplicative members. None of the above inventions and patents, taken either singly or in combination, is seen to describe the present invention as claimed.
The present invention sets forth a construction for an outdoor chair of the type known as sling chairs, wherein a fabric seating member is stretched taut between and retained by entrapment within side rails. The novel construction eliminates the need for separate sling frame and chair frame, which redundancy typifies prior art sling chair design. This advance in the art is accomplished by providing side rails adapted to accept cross members which span and space apart the two side rails. The side rails retain the stretched fabric web in conventional manner, but also connect to the cross members, thereby integrating the frame of the fabric seating member and the frame of the chair.
Each side rail has a conventional keyhole shaped slot extending along the length of the side rail. The seating member is entrapped in the slot by a rod in conventional manner. In a departure from conventional slings, the side rail extends beyond the slot, the extension having sockets for accepting the ends of each cross member. During assembly, the side rails are spread apart until the cross members are inserted into engagement with the side rails. The side rails are released from separation when the cross members are in place. Tension from the fabric then maintains the side rails and cross members in place. The side rails and cross member are thus integral with the frame of the chair. The chair is completed by installation of a front piece connecting the formerly unconnected ends of the side rails, and by attaching legs if desired.
This construction eliminates the usual duplication of sling and main frames. Fewer parts must be manufactured, held in inventory, and assembled. Costs of manufacturing and consequent cost to the consumer are therefore commensurately reduced.
Accordingly, it is one object of the invention to eliminate separate sling frame and chair frame in a sling chair.
Another object of the invention is reduce complexity and cost of manufacture of sling chairs.
Still another object of the invention is to form a sling chair wherein the side rails form part of the frame of the chair.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.

Unit 1013, China-Chen, Golden Plaza, 77 Mody Rd., T.S.T.East


This invention provides an apparatus and method for preamble detection and integer carrier frequency offset estimation, which method comprises the steps of: determining the window of useful subcarriers in preamble transformed to frequency domain based on pre-determined possible integer carrier frequency offset and the length of the preamble, so as to select the useful subcarriers; extracting a plurality of subcarrier sequences having a length equal to that of the preamble from the useful subcarriers; calculating conjugative multiplications of each subcarrier and its neighboring subcarriers in the subcarrier sequences extracted; acquiring the real part of the conjugative multiplications; calculating the cross correlations between the real part of the conjugative multiplications and known preambles modulated by DBPSK, and outputting the calculated correlation values; and detecting preamble index of a target base station with the calculated correlation values to select a target cell, and estimating integer carrier frequency offset with respect to the target base station.

In OFDM or OFDMA systems, such as IEEE 802.16d/e system, the preamble is designed in consideration to support systems working in various frequency multiplexing schemes including the scheme in which the multiplexing factor is 1. Cell ID (or IDCell) and segment number embedded in the preamble can be used as identification of the cell and the sector respectively, which are also utilized as an item of permutation generator for subcarrier mapping and as an initialization vector of pseudo-random binary sequence (PRBS) generator for subcarrier randomization. Only after the preamble pattern has been correctly detected, the MS can then correctly de-map and de-randomize the subcarrier, and further demodulate/decode OFDMA symbols following the preamble in a downlink frame.
There are altogether 114 preamble codes or preamble patterns specified in the IEEE 802.16d/e system. These preamble sequences are generated through computer searching. The preamble codes have therebetween low cross-correlation values in frequency domain and low peak to average power ratio (PAPR) in time domain. For scalable OFDMA systems such as IEEE 802.16e, the length of a preamble code is different for various FFT sizes.
The preamble codes are modulated to specific pilot subcarriers according to the corresponding segment number by:PreambleCarrierSetseg=seg+3k  (1)where PreambleCarrierSetseg specifies all subcarriers allocated to the preamble code, seg is the segment number indexed from 0 to 2, and k is a running index from 1 to the length of the preamble code.
Each preamble code has its unique preamble index, IDCell and segment number. For instance, for FFT-2048 (indicating that the FFT size equals to 2048; FFT-512 and FFT-1024 appearing hereinafter indicate that the FFT size equals to 512 and 1024, respectively), the preamble code with Index=0, IDCell=0 and Segment=0 is:
Wk=0xC12B7F736CFFB14B6ABF4EB50A60B7A3B4163EA3360F697C45075 997ACE17BB1512C7C0CEBB34B389D8784553C0FC60BDE4F166CF7B048 56442D97539FB915D80820CED D858483 (in Hex type).
The preamble code is modulated by 2√{square root over (2)} boosted BPSK modulation as:
                    {                                                                              Re                                                        {                                          X                                                                    (                        k                        )                                                              }                                                  =                                                      2                                                                                2                                            ·                                                                        X                          ′                                                                                (                          k                          )                                                                                =                                      2                                                                                2                                            ·                      2                                                                                (                                                                        1                          /                          2                                                -                                                  W                          k                                                                    )                                                                                Im                                                        {                                          X                                                                    (                        k                        )                                                              }                                                  =                0                                                                        (        2        )            where X′(k) is the preamble code after the BPSK modulation, X(k) is the boosted preamble code, and Re(•) and Im(•) are respectively real part and virtual part acquisition calculations.
After modulation, these modulated symbols are mapped to pilot subcarriers and zero is used to fill the unallocated subcarriers. As should be noted, however, if a DC subcarrier is precisely included in a pilot position to which the preamble code corresponds, no modulation will be made and the code corresponding to this position will be discarded. FIG. 1 shows the structures of the preamble of FFT-512 and FFT-1024 based on the IEEE 802.16e, wherein a preamble code is modulated at intervals of every three subcarriers except the left and right virtual carriers. A base station (BS) or a sector of a BS has its unique preamble code and is transmitted in the head of every frame.
FIG. 2 shows cross-correlation characteristics among preamble codes. As shown in FIG. 2, the cross-correlation values among different preamble codes are low, but the self-correlation values of each preamble code are high. Therefore, in the receiver of a mobile station, preamble index can be detected by the conventional cross correlation between a post-FFT preamble and the known preamble codes like the detection of the conventional pseudo noise (PN) code. Detection is also possible by the differential cross correlation method in view of preventing channel fading and timing offset. After the correlation calculation, the code with the maximum correlation value is taken as the preamble index of the target BS.
However, during the initial synchronization period, there is usually a carrier frequency offset (CFO) between the BS and the MS. The oscillator of the MS is generally not provided with high accuracy out of commercial considerations. As a result, the carrier frequency offset is larger than one subcarrier spacing, that is to say, there is an integer carrier frequency offset (ICFO) between the MS and the BS. In this case, preamble sequence in the frequency domain will be shifted along the subcarrier axis. Conventional preamble detection method cannot work in this situation. Consequently, there is a need for a preamble detection algorithm and a preamble detection apparatus operating accurately in large carrier frequency offset environment (especially in integer carrier frequency offset environment), and a need for an integer carrier frequency offset (ICFO) estimator.
Additionally, the MS needs to choose a BS with the best channel condition as the target BS for initial network access. Conventional BS or cell selection method only makes decision from the preamble detection result of one frame. However, when an MS approaches a cell edge, it can receive signals from a plurality of BSs. The fading paths between the MS and each BS are normally independent. The different fading paths will easily mislead selection of the target BS if only one preamble detection is relied upon. Accordingly, there is also a need for a reliable cell selector during the initial network access.

Apparatus and method for preamble detection and integer carrier frequency offset estimation


A reduced number of selectable inputs that enable efficient communication. Simplified tactile and optically machine readable code of raised embossments, particularly for unsighted and visually impaired persons is provided, in which each character is represented by a cell of indicia of an intuitive systematic code. For the alphabet, the cells are configured in ordered positions, which correspond to the order of the alphabet, and thereby, assist in tactile perception so that a person may easily identify the character by touch. Also, optical machines are enabled to easily read the characters; and a keyboard is provided for producing the same.

Tactile systems, such as Braille, are widely used by visually impaired persons, including blind and low-vision persons, to enable them to touch read written text. Braille is a system of touch reading which employs raised dots evenly arranged in quadrangular letter spaces or cells. Braille cells are made up of a plurality of positions that are populated by the raised dots to provide characters (e.g., letters of the alphabet or numbers), while other positions are left blank. Each particular configuration of raised dots represents a letter of the alphabet, a numeral or other symbol.
Improvements and/or alternatives to Braille have been described over the years. Some of these improvements/alternatives are described in the following patents: U.S. Pat. No. 3,197,889, entitled "Method of Forming Letters and Numbers Readable by the Blind," Micropoulou, issued Aug. 3, 1965; U.S. Pat. No. 3,363,339, entitled "Braille Cell Structure, Place, issued Jan. 16, 1968; U.S. Pat. No. 4,404,764, entitled""Message Medium Having Corresponding Optical and Tactile Messages," Wills, et al., issued Sep. 20, 1983; , and U.S. Pat. No. 4,737,108, entitled "Tactile Code for the Visually Impaired and Blind," Chepaitis, issued Apr. 12, 1988, each of which is hereby incorporated herein by reference in its entirety.
The conventional Braille system requires a high-level of skill and is not as intuitive as desired. Additionally, it and alternative systems require significant cognitive resources.

Intuitively ordered tactile characters readable by visually impaired persons


An apparatus for transporting flexible, sheet-like products, in particular printed products 9, away and/or for further processing, and having a plurality of grippers 3 which can be moved along a gripper conveying route and follow one after the other in the transporting direction, and having a plurality of suction elements 2 which can be moved along a suction element conveying route and are intended for receiving in each case one product 9 and for transferring the received product 9 to a gripper 3, the above operations taking place in a receiving and transfer region wherein the suction element conveying route runs along or parallel to the gripper conveying route.

The invention relates to an apparatus for transporting flexible, sheet-like products, in particular printed products, away and/or for further processing, having a plurality of grippers which can be moved along a gripper conveying route and follow one after the other in the transporting direction, and having a plurality of suction elements which can be moved along a suction element conveying route and are intended for receiving in each case one product and for transferring the received product to a gripper. The operations take place in a receiving and transfer region.
Such apparatuses are suitable for receiving individually, by means of the suction elements, products which are arranged in stack form or are supplied in imbricated formation and for transferring the received products to grippers, which then feed the gripped products for further processing. In this case, the suction elements always transfer precisely one product to each gripper, with the result that it is made possible for the apparatus to receive the products individually and to feed them individually for further processing.
It is an object of the invention to develop the above described apparatus such that, with an economically viable outlay on the one hand, it is possible to guarantee the increased reliability of error-free product receiving and product transfer operations and on the other hand, it is possible to increase the speed of the receiving and transfer process.
The above and other objects and advantages are achieved according to the invention in that, in the receiving and transfer region, the suction element conveying route runs along or parallel to the gripper conveying route.
By virtue of the suction element conveying route and the gripper conveying route running in this way according to the invention, suction elements and grippers move uniformly one beside the other along an at least largely common curved path during the product receiving and product transfer process. In contrast to known apparatuses, in which suction elements and grippers move on different curved paths during the receiving and transfer process, this has the advantage that no relative movements occur between the suction elements and grippers as a result of different curved paths, with the result that the suction elements and grippers, which according to the invention move at the same speed on mutually corresponding curved paths, are arranged in a largely stationary manner in relation to one another by way of their base and/or carrier units. This achieves simplified activation and synchronization of the moveable and/or controllable suction element and gripper parts since, in the case of this control and synchronization, there is no need to take account of different curved paths of the base and/or carrier units of suction elements and grippers. This simplification means that errors during the product receiving and product transfer operations are largely ruled out. In addition, the simplification means that the receiving and transfer process can take place at high speed without this making it necessary to accept the error-free sequence of the receiving and transfer process being adversely affected.
It is preferred if the length of that section of the suction element conveying route which runs along or parallel to the gripper conveying route is such that at least two successive grippers are located in this section. This minimum length of the section in which the two conveying routes run along mutually corresponding curved paths ensures that the entire receiving and transfer process can take place within said section, with the result that it is possible to rule out relative movements of the base and/or carrier units of suction elements and grippers during this process.
In the receiving and transfer region, the gripper conveying route and the suction element conveying route may run, for example, on concentric circular paths. This makes it possible for the suction elements and grippers to be conveyed in a straightforward manner since, in both cases, they may be driven by means of one or more transporting wheels.
It is advantageous if, in the receiving and transfer region, in each case one gripper and one suction element are assigned to one another. In particular, in the receiving and transfer region, the distance between two successive grippers may correspond to the distance between two successive suction elements. This means that in each case one gripper and one suction element can pass through the receiving and transfer region at an optimized distance from one another on their mutually corresponding curved paths, which minimizes the mechanical outlay required for the arrangement as a whole and optimizes the freedom from error and speed of the receiving and transfer process.
In the receiving and transfer region, the suction element conveying route and gripper conveying route preferably run approximately centrally along, in particular centrally above, the products which are to be received. This means that no mechanical devices have to be provided laterally alongside the products which are to be received and have been received.
As has already been mentioned, suction elements and grippers may be conveyed in the receiving and transfer region by in each case one transporting wheel. It is likewise possible to provide just a single transporting wheel, which conveys both the suction elements and the grippers in the receiving and transfer region. For the case where the grippers are conveyed by means of a separate or common transporting wheel, said grippers can be coupled to the transporting wheel in an either releasable or non-releasable manner during the transportation. In the case of non-releasable coupling, the grippers describe basically a circular path about the transporting wheel, one section of this circular path forming the receiving and transfer region. In another section of the circular path, the products previously transferred to the grippers are then discharged to a downstream conveying apparatus or any other desired further-processing station. In the case of releasable coupling of the grippers to the transporting wheel, the grippers can leave the circular path of the transporting wheel, once they have received a product, in order to convey the received products in a region which is spaced apart from the transporting wheel. For this purpose, the grippers are preferably coupled to a conveying means which, in the receiving and transfer region, runs along the corresponding section of the transporting wheel.
It is advantageous if the suction elements are retained on the suction element-transporting wheel, and/or on the respectively associated base and/or carrier unit which, for its part, is firmly coupled to the transporting wheel, such that they can be pivoted in each case between a receiving position and a transfer position. This pivoting capacity allows the suction elements to be activated in a specific manner during the receiving and transfer process such that a relative movement takes place between the suction element and associated gripper, said relative movement ensuring that a product which has been attached by suction is transferred to the gripper.
Furthermore, it is advantageous if the suction elements each have a guide surface which acts in the transfer position of said suction elements and is intended for guiding in a defined manner between the guide surface and a counter-pressure apparatus a product which is not retained by means of suction action. The guide surface serves for guiding in a defined manner the products which have already been received and transferred to a gripper and for ensuring that that section of the product which is not retained by a gripper cannot move in an uncontrolled manner and also, furthermore, preferably does not come into contact with one or more grippers following in the conveying direction. In particular, the interaction of the guide surface with the counter-pressure apparatus may also ensure that products transferred to a gripper are still guiding reliably even when the respective gripper has already released them again for the purpose of further transportation or further processing.
The functioning of the guide surface and counterpressure apparatus will also be explained clearly within the context of the description of the figures.
It is possible, within the context of the invention, for each gripper assigned to a suction element to be designed as a gripper pair, it being the case that, in the receiving and transfer region, the suction element is arranged between the two grippers of the respectively associated gripper pair. Alternatively, however, it is also possible for each suction element assigned to a gripper to be designed as a suction element pair, it being the case that, in the receiving and transfer region, the gripper is then arranged between the two suction elements of the respectively associated suction element pair.
Within the context of the invention, the gripper movements, the suction element movements and the activation of the suction elements are preferably controlled by control guides and/or toothed-belt gear mechanisms.

Apparatus for transporting flexible, sheet-like products


The present invention provides a polytrimethylene terephthalate composite fiber characterized in that the composite fiber is a plurality of single filament which comprises two kinds of polyester components laminated to each other in a side-by-side manner or an eccentric sheath-core manner, at least one polyester component is polytrimethylene terephthalate and the composite fiber satisfies the following conditions: the content of trimethylene terephthalate cyclic dimer in polytrimethylene terephthalate is 2.5 wt % or less, the fiber-fiber dynamic friction coefficient is from 0.2 to 0.4, the degree of intermingling is from 2 to 60 point/m and/or the number of twists is from 2 to 60 T/m and the fiber size fluctuation U % is 1.5% or less.

A polytrimethylene terephthalate (hereinafter referred to as PTT) fiber have been known in the prior documents such as J. Polymer Science: Polymer Physics Edition Vol. 14, pages 263 to 274 (1976) or Chemical Fibers International Vol. 45, pages 110 to 111 April (1995).
These documents describe a basic characteristic of a stress-strain property of the PTT fiber; that is, the PTT fiber is low in initial modulus and excellent in elastic recovery, which is suitable for clothing and carpet use.
Japanese Examined Patent Publication No. 43-19108, Japanese Unexamined Patent Publication Nos. 11-189923, 2000-239927 and 2000-256918, and EP1059372A disclose a side-by-side type composite fiber containing PTT as one component or two components thereof.
These prior documents disclose that a side-by-side type or an eccentric sheath-core type composite fiber in which PTT is used as at least one component thereof (hereinafter referred to as a PTT composite fibers) have a latent crimpability, and the crimps develop by heat treatment, and exhibit a favorable stretchability and a soft touch.
According to the study of the present inventors, although products obtained from the PTT composite fibers are excellent in stretchability and softness, problems have been found in the post-treatment process such as knitting/weaving or dyeing and the uniformity of dyed product as described in items I, II and III below:
I. Troubles in Knitting/Weaving Process
As the preparation prior to the knitting/weaving, a warping process is employed before the knitting process, and a warp preparation process and a twist yarn preparation process are employed before the weaving process.
When the PTT composite fiber is used in a warp-knitting process, "opening of single filaments" may occur due to the tension fluctuation during the knitting operation, whereby the adjacent fibers are interfered with each other to result in filament breakage.
When a twist yarn is formed of the PTT composite fibers and used for producing a woven fabric, there is a problem in that white powder may be generated during the twisting and/or weaving process and is deposited on guides in the passage to result in the yarn breakage.
FIG. 1 is a simplified illustration of a photograph of the PTT composite fiber surface after being twisted and twist-set by wet heat observed by a scanning electronic microscope. It will be apparent from FIG. 1 that white powder is generally uniformly deposited on the surface of single filament.
FIG. 2 is an example of a chart obtained by measuring white powder deposited on a tension control guide of a loom in accordance with a differential scanning calorimetry (DSC).
This curve exhibits endothermic peaks at about 230° C. and about 250° C. The peaks at about 230° C. and at about 250° C. coincide with the melting temperature of PTT and that of a cyclic dimer of trimethylene terephthalate, respectively. Accordingly, it is apparent that the white powder deposited on a guide or others is PTT or trimethylene terephthalate cyclic dimer which is a by-product of the former.
The higher the crimpability of the developed crimps and the more of a number of twist, the more the white powder is derived from PTT. If the number of twists is 1000 T/m or more, the frictional abrasion of the twist yarn becomes so significant that an abrasive trace can be observed by a scanning electronic microscope. Thus, the PTT composite fiber is difficult to use as a high twist yarn.
Also, the higher the twist-setting temperature after being twisted, the more the white powder is derived from the cyclic dimer of trimethylene terephthalate.
While it is not apparent why such white powder is generated, one reason may be the following:
PTT composite fiber, especially that having a high stretchability, has not only latent crimpability but also developed crimps developed prior to being heat-treated; in other words, it is characterized as having apparent crimpability. It is surmised that such a side-by-side type composite fiber having developed crimpability is significantly higher in contact resistance with guides or others in the preparation process of knitting/weaving than that having non-developed crimpability to result in the generation of white powder.
Also, it is surmised that during the twist-setting process after twisting, trimethylene terephthalate cyclic dimer contained in a PTT composite fiber separates out from the fiber interior to the surface thereof to cause white powder.
There is a proposal in WO99/39041 to eliminate the yarn breakage during the spinning or false-twist texturing process by imparting PTT fiber with a special finishing agent. However, there is no description therein of the PTT composite fiber having the developed crimpability wherein crimps are developed.
Also, in the above prior document, there is no disclosure of the problem of the entanglement of fibers during the knitting process or the generation of white powder during the knitting/weaving process, much less the disclosure or suggestion of a solution thereto.
II. Troubles in Dyeing Process
It is known that, besides fabric dyeing or print dyeing, a dyed knit/woven fabric may be obtained by a yarn-dyeing method.
Since a pattern is formed in the knit/woven fabric obtained by the yarn-dyeing method wherein colors of the respective fibers are different from each other, a high-grade fashionable product results.
While the yarn-dyeing method includes hank dyeing or cheese dyeing, the latter is mainly used nowadays because of the dyeing economy thereof.
The knit/woven fabric obtained from the cheese-dyed PTT composite fibers more easily develops crimps during the dyeing process in comparison with a false-twist textured yarn of PTT or polyethylene terephthalate (hereinafter referred to as PET). Accordingly, if the cheese-dyed PTT composite fibers are used for the knit/woven fabric, there is a feature in that the favorable stretchability is obtained due to high crimps.
Contrary to such a feature, it has been found that, when the PTT composite fibers are cheese-dyed, oligomer extracted from the fiber is deposited on the dyed cheese to deteriorate the dyeing uniformity.
That is, when a dyeing liquid circulates from inside of the cheese to outside thereof, oligomer separated out from the PTT composite fibers is dissolved in the dye liquid and deposited on the fiber. The portion of the fiber on which the oligomer is deposited causes an uneven dyeing or a loss of color clarity. Dyeing troubles caused by oligomer are not limited only to cheese dyeing but also appear in fabric dyeing.
According to analysis by the present inventors, it has been found that a main component of the oligomer is a cyclic dimer of trimethylene terephthalate.
Although the reason is not apparent why a large amount of cyclic dimer is separated out from the PTT composite fibers, it is surmised that a low PTT orientation in the PTT composite fibers allows the cyclic dimer to move toward the fiber surface.
Japanese Patent No. 3204399 discloses a PTT fiber and refers to the content of oligomer in the PTT fiber for the purpose of restricting the contamination of orifices in a spinneret. However, the content is high and there is no disclosure at all of white powder being generated during the twisting, heat-setting and weaving of PTT composite fibers or oligomer troublesome in the dyeing process thereof.
Thus, PTT composite fibers free from troubles in the dyeing process are strongly desired.
III. Dyeing Uniformity
The dyeing uniformity of a PTT composite fiber product is an important factor.
It has been found that the following two problems deteriorate the dyeing uniformity when the PTT composite fibers are industrially produced.
One of the problems is the yarn bending. If the difference in intrinsic viscosity between two polymers used is made to be larger for the purpose of improving the stretchability and the stretchback property of the resultant composite fibers, yarn bending is generated due to the difference in melting viscosity between the two polymers extruded from an orifice during the spinning, which causes fiber size fluctuation in the lengthwise direction of the resultant composite fiber.
The other of the problems is the contamination of the orifice from which the melted polymer is extruded. When the PTT is spun, polymer may deposit on the periphery of the orifice as the spinning time passes to result in the contamination so-called "eye mucus". This contamination is peculiar to PTT, and the larger the difference in intrinsic viscosity between the two polymers, the more significant this phenomenon becomes. It has been found that when the "eye mucus" generates, the extruded fiber becomes uneven (because of the generation of a so-called "jerk") not only to reduce the spinning stability but also increase the fiber size fluctuation U % of the composite fibers obtained. A fabric obtained from the PTT composite fibers having a large fiber size fluctuation is unevenly dyed to largely lower the product grade.
To solve the problem of yarn bending, a spinning method is proposed, in Japanese Examined Patent Publication (Kokoku) No. 43-19108, BP 965,729 and Japanese Unexamined Patent Publication (Kokai) No. 2000-136440, using a spinneret having orifices in which flow paths for two polymers are slanted.
Since the prior art disclosed in these documents, however, is a system in which two polymers having the difference in intrinsic viscosity are extruded from an orifice directly after they meet together, if the difference in melting viscosity between the two polymers is large, it is impossible to sufficiently prevent the deviation of a flow of melted polymer, and as a result, the fiber size fluctuation is not suppressed enough.
Accordingly, it is strongly desired that PTT composite fibers free from yarn breakage during the knitting/weaving process and having high stretchability, high stretchback property and dyeing uniformity, and a method for the production thereof, are developed.

Composite fiber having favorable post-treatment processibility and method for producing the same


A combination of a semi-soluble or insoluble ethylmethacrylate polymer and a soluble or semi-soluble methacrylic acid polymer, optionally with a partially sulfonated resol resin which provides improved resistance to staining by acid colorants in a fibrous polyamide substrate.

1. Field of the Invention
This invention relates to a fibrous polyamide substrate having durable resistance to staining by acid colorants and to a method of rendering a fibrous polyamide substrate durably resistant to staining by acid colorants.
2. Description of Prior Art
Fibrous polyamide substrates, such as nylon carpeting are susceptible to staining by both naturally occurring and commercial acid colorants found in many common foods and beverages. The demand for reduced staining from such acid colorants has by and large been met previously by treatment with compositions comprising sulfonated napthol and or phenol or sulfonated phenol-formaldehyde condensation products as disclosed for example in the following patents: U.S. Pat. No. 4,501,591, Ucci and Blyth; U.S. Pat. No. 4,592,940, Blyth and Ucci; U.S. Pat. No. 4,680,212, Blyth and Ucci; U.S. Pat. No. 4,780,099, Creshler, Malone and Zinnato; and U.S. Pat. No. 4,865,885, Herlant and Al, or by treatment with compositions comprising sulfonated novalak resins together with polymethacrylic acid as disclosed in U.S. Pat. No. 4,822,373 (Olson, Chang and Muggli). The use of polymers or copolymers of methacrylic acid of low weight average molecular weight and low number average molecular weight is described in U.S. Pat. No. 4,937,123 (Chang, Olson and Muggli).
The initial stain resistance properties imparted to polyamide substrates, such as carpeting, that have been treated using the above mentioned compositions degenerate significantly with each wet cleaning the substrate receives. Improved stain resistance after wet cleaning can be achieved by increasing the amount of the phenolic resin in the stain resist product or by increasing the amount of stain-resist product initially applied to the substrate, however, this generally leads to discoloration caused by yellowing of the substrate initially and further discoloration upon exposure to oxides of nitrogen and/or light. This discoloration in most cases is attributed to dihydroxydiphenol sulfone and its associated SO.sub.2 group.
Stain resist products currently available in the market place are generally novalak--type resins based on dihydroxydiphenyl sulfone and phenol sulfonic acid condensed with aldehyde in acid media, or dihydroxy diphenyl sulfone and naphthalene sulfonic acid condensed with aldehyde at low pH.
It is generally known that increasing the ratio of dihydroxydiphenyl sulfone to the phenol sulfonic acid or napththalene sulfonic acid increases the stain resistance properties of the resin and subsequently causes a higher degree of yellowing or discoloration initially and further discoloration upon exposure to oxides of nitrogen and/or light.
It is also evident that when the ratio of phenol sulfonic acid or naphthalene sulfonic acid to dihydroxydiphenyl sulfone increases, the result is lower stain-resist properties and less discoloration.
The addition of acrylic polymers and/or copolymers to the previously mentioned novalak resin condensation products as disclosed in U.S. Pat. No. 4,822,373 (Olson, Chang and Muggli) allows the use of a novalak resin in small quantities and larger quantities of the acrylic resin. With this combination of novalak resin and acrylic resin, big improvement in the light fastness or less discoloration is achieved due to the dramatically reduced percentage of novalak resin in the product mentioned above which is adjusted to obtain a desired minimum level of discoloration while maintaining a maximum level of durability to wash. The high level of initial stain resistance is supplied primarily by the methylacrylic polymer and/or copolymer and after wet cleaning the stain resistance is supposedly maintained by the novalak resin, the acrylic having largely been removed during the wet cleaning process.

Polyamide substrate having stain resistance, composition and method


A multi-player video game server includes a player control interface, a video interface, and a game engine. The player interface couples the game server to a network and can receive game control data over the network from multiple players. Each player has a game control device at which game control data can be input. The video interface couples the game server to a video transmission network and transmits game display video over the video transmission network. The game engine is coupled to the player interface and the video interface and includes a processor and a memory. The memory stores multi-player video game instructions that configure the processor to process game control data and render the game display video that is then provided to the video interface for transmission over a video network. A multi-player video gaming method includes receiving a number of player input data connections at a game server. Each of the game control data stream includes player input data from a different player of a multi-player video game. An output display image is generated at the game server by executing video game instructions to process the player input data connections from the multiple players as inputs to the same multi-player game. The output display image is then transmitted over a channel of a video transmission network.

Video game are a popular entertainment activity that players can engage in through the use of a dedicated video game console or a personal computer. Game consoles and personal computers can be used to receive input from an attached game pad, keyboard, joystick or other game controller, process video game software, and display video game images on a connected television or monitor. Video game consoles and personal computers also can be used for multi-player games. Multi-player games typically require each player to use different game controllers attached to the same game console or computer. Multi-player game systems can also be implemented using game consoles or computers that send data to each other over a network or modem connection. In these multi-player systems, each of the multiple players are required to have compatible local video game consoles and/or home computer, and local copies of particular game software to play games with each other. Multi-player video games may, however, be more conveniently provided to players by a system in which the players do not require local game consoles, home computers, or other specialized devices.
In general, in one aspect, the invention features a multi-player video game server. The video game server includes a player interface, a video interface, and a game engine. The player interface couples the game server to a network and can receive game control data over the network from multiple players. Each player has a game control device used to input game control data. The video interface couples the game server to a video transmission network and transmits game display video over the video transmission network. The game engine is coupled to the player interface and the video interface and includes a processor and a memory. The memory stores multi-player video game instructions that configure the processor to process game control data and render the game display video that is then provided to the video interface for transmission over a video network.
In general, in another aspect, the invention features a multi-player video gaming method. The method includes receiving a number of player input data connections at a game server. Each of the game control data stream includes player input data from a different player of a multi-player video game. An output display image is generated at the game server by executing video game instructions to process the player input data connections from the multiple players as inputs to the same multi-player game. The output display image is then transmitted over a channel of a video transmission network.
In general, in another aspect, the invention features a method for providing a multi-player video game. The method includes receiving player input data at a game control device and transmitting the player input data over a network to a game server. The method also includes receiving a video game image at a video terminal that was generated at the game server in response to the player input data from the game control device and player input data from another game control device.
Implementations may include one or more of the following features. The output display image (i.e., the game display video image) may be divided into different subdivisions each of which is associated with a different one of the players. The player input data may be touch-tone (i.e., dual-tone multi-frequency (DTMF)) data that is input by the players using telephone keypads. The transmitted output display image may be receivable by both players and an audience of non-players. The same output display image may be sent to all players of the multi-player game, or the game engine may generate different output display images for different players; the different output display images may be transmitted over different channels of the video transmission network. The game server may support more than one multi-player game (i.e., the game server may receive player input data connections from a second group of players and send output display images to that second group that are generated based on the game control data received from those players). The video game instructions for different multi-player games may be executing at different game engines. The game engines may include commercially available (mass-market) video game hardware such as Sony Playstation(copyright), Nintendo(copyright) or Sega(copyright) video game hardware. The game control streams may be received over a network that is different from the video transmission network. For example, the game control streams may be received over a point-to-point telephone network or a packet data network, while the video may received over a broadcast video network. The video transmission network may be a one-way video transmission network that can transmit video on multiple channels, and each channel may be receivable at multiple display terminals.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.


An anti-vibration device for damping torque designed to couple an engine with a motor vehicle chassis with a view to limiting displacements of the engine, comprising a central reinforcement simply inserted in a nest-fit between elastomer lobes projecting in the main direction of displacement inside an annular reinforcement. The lobe which is compressed when the engine produces a driving force is thicker than the others and the first reinforcement is flat perpendicular to the main direction of displacement.

In the known anti-vibration devices of this type, the first and second elastomer limiting units consist of two diametrically opposed arms which are joined at a central part moulded onto the first reinforcement.
These known anti-vibration devices have the following disadvantages, depending on how they are oriented relative to the displacement:
Furthermore, since only a small volume is free for mounting the anti-vibration device, the elastomer arms are short and are therefore subjected to particularly high stress, which also has an adverse effect on the capacity of the coupling device to withstand fatigue.


A power transmission apparatus for four-wheel drive vehicle which uses a hydraulic pump to absorb a rotational speed difference caused between front and rear wheels or left side and right side wheels to thereby materialize the four-wheel drive state and which is provided at a fixed housing with a variable throttle for adjusting oil pressure at the hydraulic pump. The variable throttle is adjustable of a degree of its opening by brake oil pressure generated by the braking action during the drive operation of an electromagnetic actuator or oil pressure introduced into a power cylinder disposed in a steering mechanism. Also, outside the fixed housing are provided fins for dissipating the heat content of operating oil at the hydraulic pump. Furthermore, on the slidable contact surface of a casing of the hydraulic pump with the fixed housing is provided sealing means for preventing the operating oil in the hydraulic pump from leaking therefrom.

1. Field of the Invention
The present invention relates to a power transmission apparatus for four-wheel drive vehicle for absorbing a rotational speed difference between the front wheels and the rear wheels or the left side wheel and the right side wheel by means of oil pressure generated in a hydraulic pump.
2. Description of Related Art
A four-wheel drive vehicle running by transmitting a driving force of an engine to all four wheels is of course superior in traveling stability on a road lower in a coefficient of friction, such as a snow-covered road or a frozen road, and a bad road, such as a gravel road or a dirt road, and also, has high traveling stability in the acceleration and deceleration and the high speed running even when traveling on a paved road. Such four-wheel drive vehicle has hitherto been especially highlighted as the vehicle realizable of comfortable traveling in spite of any road condition, natural condition, such as weather condition, and running state.
The four-wheel drive vehicle is basically realizable by directly connecting four wheels of front, rear, left side and right side to an engine of driving source respectively. In this case, different turning paths between the front and the rear wheels or between the left side and the right side wheels make it impossible to absorb a rotation speed difference generated between both wheels during the turning. Especially, during the sharp turning, the rear wheel inside the turning circle causes a slip and is dragged: so-called tight corner braking phenomenon occurs, thereby creating the problem that the turning performance deteriorates. Therefore, recently, such four-wheel drive vehicle has been dominant that is provided with a power transmission apparatus which can absorb the rotation speed difference between the front and the rear wheels or the left side and the right side wheels and distribute the driving force to both wheels corresponding to the rotation speed difference. A hydraulic pump for generating oil pressure corresponding to the rotational speed difference is used as one of the power transmission apparatuses, which is so constructed that a rotor connected in association with one of the front and the rear wheels is housed in a casing connected in association with the other, thereby causing between the rotor and the casing relative rotation corresponding to the rotational speed difference between both wheels. Magnitude of oil pressure generated within the hydraulic pump, with respect to the characteristic thereof, corresponds to the speed of relative rotation between the rotor and the casing, in other words, the extent of rotational speed difference between the front and the rear wheels or the left side and the right side wheels. Since the generated oil pressure acts between the rotor and the casing to restrict the relative rotation, the driving force corresponding to the rotational speed difference between both wheels is transmitted from one of the front and the rear wheels or the left side and the right side wheels to the other, thereby the four-wheel drive state is realized.
In such four-wheel drive device, in order to prevent generation of the aforesaid tight corner braking phenomenon, it is earnestly desired to reversibly obtain low generated oil pressure so as to loosely connect both wheels when the rotational speed difference between the front and the rear wheels or between the left side and the right side wheels is smaller. When the rotational speed difference between those wheels is larger, it is earnestly desired to reversibly obtain high generated oil pressure so as to tightly connect both wheels. In order to meet such requirement, adjusting means for adjusting oil pressure generated in the hydraulic pump must be used. Herein, since both the rotor and the casing rotate, when adjusting means for adjusting oil pressure is provided either at the rotor or the casing, it is difficult to perform the adjustment.

Power transmission apparatus for four-wheel drive vehicle


A system for retrieving a portable rumble strip from a roadway includes a carrier mountable to a vehicle for transporting retrieved portable rumble strips and a winch mountable to the carrier. The carrier has a support surface configured to support a rumble strip. And the winch includes a rotatable drum and a lead with a major dimension being a length dimension. A proximal end of the lead is connected to the drum such that rotation of the drum winds the lead about the drum. A hook is connected to a distal end of the lead opposite the proximal end. The hook is configured to engage and hold a portable rumble strip as the drum rotates to draw the lead and the hook to the winch, thereby drawing the engaged portable rumble strip into the carrier.

Roadway warning devices, specifically the roadway warning devices commonly referred to as rumble strips, provide a perceptible noise and warning vibration when automotive vehicles, including both passenger vehicles and trucks, drive over the rumble strips. The noise and vibration is intended to warn the vehicle driver of an approaching condition that requires a lower speed or special attention, such as a work site, construction site, slow speed zone, checkpoint, toll booth, and so on, without alarming the driver and without adversely affecting the stability of the vehicle. Some types of rumble strips are intended to be permanently installed for long-term use, while others are intended to be portable for temporary use at work zones and other applications of relatively short duration.


A windbreak arrangement for a cabriolet includes a windbreak arch of bipartite construction in the transverse direction of the vehicle consisting of a first, driver-side windbreak arch member and a second, passenger-side windbreak arch member. The driver-side windbreak arch member is mounted on the driver's seat and the passenger-side windbreak arch member is similarly mounted on the passenger seat. Additionally, each windbreak arch has a curtain cassette with a curtain capable of being extended horizontally as a windbreak curtain over the region behind the corresponding front seat, providing a good variable windbreak function with easy access to rear seats.

This invention relates to windbreaks for cabriolets.
In a cabriolet having an open top, the airstream is directed over the vehicle by the windshield, producing turbulence from behind in the passenger compartment. This leads to an annoying tousling of hair and an unpleasant draft at the back of the neck. Besides, the heat in the passenger compartment is diminished since the resulting motion of the air stirs up and removes the normal cushion of warmth in the passenger compartment. Furthermore, there is a high noise level, especially at higher speeds, preventing or at least interfering with conversation as well as with the audibility of music and also traffic messages.
To mitigate these problems, so-called windbreaks have been provided in the form of framed nettings or roller blinds which are mounted behind the front seats in the region of the passengers' heads.
In the case of smaller, two-seater cabriolets, the rear-body portion or trunk of the vehicle directly adjoins the front seats. In that case, it is sufficient for the suppression of a draft simply to provide a vertical windbreak. For this purpose, German Patent No. 196 17 702 discloses a roll-up windbreak in a cabriolet having a rollover bar which is arranged more or less at the level of the hood located behind the front seats along with an adjacent cover box which is open toward the front. The roll-up windbreak can be extended from below upwardly into a service position and then attached to the transverse member of the rollover bar. For larger cabriolets, especially those with rear seats, such a fixed roll-up system behind the front seat would constitute an undesirable barrier to entry into the rear seats.
European Patent Publication No. 0 340 796 discloses a four-seater cabriolet having a similar roll-up windbreak system located at the floor of the vehicle. Such a roll-up arrangement extending from the floor of the vehicle will also stop an airstream originating at the rear seats from moving toward the front seats. However, since most cabriolets have a domed center tunnel such a roll-up arrangement is available in only the few cabriolet designs which have a flat floor.
In the case of larger cabriolets, in particular four-seaters, to stop an airstream entering the interior of the vehicle from behind downwardly over the back seats, U.S. Pat. No. 5,219,201 discloses a windbreak made in two parts, a vertical part being arranged behind the front seats more or less at head level, and a horizontal part covering the adjacent rear section, at about sill height, in particular over the rear seats.
European Published Application No. 0 779 172, for example, discloses a bipartite windbreak made so that the two parts can be folded together and stowed behind a rear seat backrest. In another known arrangement disclosed in German Gebrauchsmuster No. 93 03 717, a vertical part consisting of a netting stretched in a frame is inserted in holders at the sides of the vehicle. On the underside of the frame, another, flexible netting is attached by one end so that it may be spread over the rear seat area and attached at its posterior edge to the rear seat backrest by hook-and-loop tapes when necessary.
U.S. Pat. No. 5,211,718 describes another embodiment of a windbreak which includes a U-shaped roll-over bar having legs mounted on opposed sides of the vehicle in the region behind the front seats, the cross-bar of the U-shaped roll-over bar passing above the occupants' head level in the transverse direction of the vehicle. In addition, this arrangement includes a roller unit having a wind-up roller extending in the transverse direction of the vehicle near the cross-bar of the U-shaped roll-over bar. The roller is wound with a windbreak which is capable of being rolled up and unrolled, the wind-up roller being spring-loaded in the roll-up direction. When the windbreak is unrolled from the roller into a service position, it covers the area enclosed by the U. In this arrangement, the roller is in the form of a cassette located at the sill level, and the windbreak can be quickly extended from the bottom to the top of the area and hooked to the cross-bar to retain it in the service position. Adjacent to the cassette and connected to it, an additional windbreak part having a frame with netting extends horizontally to the rear. This second posterior windbreak part protects the rear seat area when it is unoccupied.
Four-seater cabriolets, or those having a storage space of some size behind the front seats, are normally two-door vehicles. All of these windbreak embodiments are attached to the vehicle body and, in combination with a horizontal covering of a rear portion of the vehicle, extend over the entire width of the vehicle. Hence, the windbreak disadvantageously creates a barrier at the sill level, barring access to the rear seats, so that the rear seats cannot be used in combination with the windbreak. Hence, nearly all conventional windbreak arrangements are removable, and have a correspondingly expensive construction. There is also the additional problem of stowing a removed windbreak in view of the space limitations of cabriolet.


A holder for carrying an open umbrella on the back of a person. The umbrella holder includes a harness for securing the holder to the person and an umbrella supporting member. The supporting member is connected to the harness so as to position the umbrella proximate a center of the back of the person when the harness is appropriately secured. An attachment member permits attachment of the open umbrella to the supporting member. The attachment member optionally permits pivotal movement of the umbrella for optimum protection.

The umbrella is one of the more practical inventions known to mankind and has been used for many centuries. In addition to providing shelter from the rain, it is also used for protection from the increasingly dangerous rays of the sun. Although the umbrella is a very efficient device for shielding and protecting us, it has one major drawback--it requires the user to hold the umbrella with their hand or hands. This can be particularly inconvenient when the user needs their hands free to hold other things, such as a briefcase, a purse, groceries, or a dog leash.
Devices are known which are designed to make carrying a closed umbrella more convenient. Examples include U.S. Pat. Nos. 4,558,807, 4,261,494 and 702,398. Such devices typically include a sheath or other embracing member for holding the closed umbrella, and a strap or belt for carrying the umbrella on a shoulder or the waist of the user.
At least one device is also known for carrying an open umbrella on a person without use of the hands. U.S. Pat. No. 2,926,826 discloses such a device. In this arrangement, a complex adjustable harness is worn on the shoulders of the user. Although the device is designed to hold a closed umbrella on the back of the harness, it only provides for holding an open umbrella on the front of the user. Moreover, the supporting member is off to the side, attached to one of the shoulder straps. This arrangement has certain disadvantages, including interference with the head rotation and visual range of the user, and poor coverage due to its off-center position.
What has been needed is a simple holder for carrying an open umbrella on a person, which is constructed to position the umbrella so that the user will have optimal protection from the elements.