A superconducting magnet electrical circuit is provided for quench protection. A superconducting coil assemblage is provided including a plurality of spatially separated main and secondary magnet coil portions. The main magnet coil portions are connected in series to form at least one main coil series circuit. The secondary magnet coil portions are also connected in a series to form at least one secondary coil series circuit. At least one temperature limiting circuit is also provided. The temperature limiting circuit may be a quench heater circuit or a quench resistor circuit. The temperature limiting circuit has a plurality of quench heaters or a plurality of quench resistors connected with the superconducting coil assemblage. A superconductive switch is coupled with the superconducting coil assemblage.

1. Field of the Invention
The invention relates to superconducting magnets. More particularly, a balanced quench protection circuit is provided to protect its superconductive assemblage from damage during a quench.
2. The Prior Art
As is well known, a magnet coil wound of superconductive material can be made superconducting by placing it in an extremely cold environment. For example, a coil may be made superconducting by enclosing it in a cryostat or pressure vessel containing a cryogen. The extreme cold enables the superconducting wires to be operated in the superconducting state. In this state, the resistance of the wires is practically zero. To introduce a current flow through the coils, a power source is initially connected to the coils for a short time period. In the superconducting state, the current will continue to flow through the coils, thereby maintaining a strong magnetic field. In other words, because superconductive windings offer no resistance to electrical current flow at low temperatures, the superconducting magnet is persistent. The electric current that flows through the magnet is maintained within the magnet and does not decay noticeably with time. Superconducting magnets find wide application in the field of magnetic resonance imaging (xe2x80x9cMRIxe2x80x9d).
In a typical MRI magnet, the main superconducting magnet coils are enclosed in a cylindrically shaped cryogen pressure vessel. The cryogen vessel is contained within an evacuated vessel and formed with an imaging bore in the center. The main magnet coils develop a strong magnetic field in the imaging volume of the axial bore.
A common cryogen is liquid helium. During superconducting operation, liquid helium boils to form helium gas. The gas is either recondensed for recycling and reuse or is vented to the atmosphere.
A major concern in such apparatus is the discontinuance or quenching of superconducting operation. Quenching can produce undesirable and possibly damaging high temperatures and voltages within the magnet. During a quench event, the current in the persistent superconducting coils decays rapidly. The rapid decay is as a result of resistive zone(s) developed in the coils for example due to thermal disturbance. Quenching may occur from an energy disturbance, such as from a magnet coil frictional movement. The energy disturbance heats a section of superconducting wire, raising its temperature above the critical temperature of superconducting operation. The heated section of wire becomes normal with some electrical resistance. The resulting I2R Joule heating further raises the temperature of the section of wire increasing the size of the normal section. An irreversible action called quench then occurs. During a quench, the electromagnetic energy of the magnet is quickly dumped or converted into thermal energy through the increased Joule heating.
For MRI application, a homogeneous magnetic field is required in the imaging volume. To provide the required homogeneity, the magnet coil is divided into a plurality of sub-coils. The sub-coils are spaced along and around the axis of the superconducting magnet such that they are not thermally connected. As a result, when only one of the superconducting coils quenches, the entire energy of the strong magnetic field may be dumped into the quenching coil. A hot spot and possible damage is caused unless a suitable quench system is provided. Quench protection can be accomplished by quickly quenching the other coils or sending part of the energy to dump resistors. Damage from rapid rise in temperature and voltage, or from quick electro-magnetic force change in the magnet, is thereby prevented.
A number of quench systems for protection of superconducting magnets are known. For example, U.S. Pat. No. 6,147,844 to Huang et al, U.S. Pat. No. 5,739,997 to Gross, and U.S. Pat. Nos. 5,650,903 and 5,731,939 to Gross et al relate to quench protection circuits for superconducting magnets.
An actively shielded MRI magnet consists of main coils and bucking coils. These coils produce a homogeneous field in the image volume and reduce fringe fields. Most of the superconducting MRI magnets are made of coils that are symmetric with respect to a symmetry mid-plane. During a quench, the current in different coils may not decay at exactly the same rate. A net differential force acting on the coils and coil supporting structure could thereby be induced. The net differential force in the right and left halves of the magnets and/or between the main coil and the bucking coil structures results in an unbalanced quench. An unbalanced quench could potentially damage coil supporting structures, depending on the severity of the unbalance. Therefore, an unbalanced quench is undesirable for supporting structures without a large built-in safety margin in the structural design. A large safety margin can increase cost and/or space occupation.
To solve the above problems, a superconducting magnet electrical circuit is provided. The circuit results in protection of a superconductive magnet through a balanced quench. A superconducting coil assemblage is provided including a plurality of spatially separated main and secondary magnet coil portions. The main magnet coil portions are connected in series to form at least one main coil series circuit. The secondary magnet coil portions are likewise connected in series to form at least one secondary coil series circuit. At least one temperature limiting circuit with a plurality of quench heaters or quench resistors is also provided. The temperature limiting circuit is connected in parallel with the superconducting coil assemblage. When a quench heater circuit is used, the circuit may include a plurality of quench heaters connected in parallel with each other. When a quench resistor circuit is used, the circuit may include a plurality of quench resistors connected in series or in parallel with each other.
Thus, the secondary magnet coil portions, for example, two bucking coils, are grouped together in a sub-circuit. The main magnet coils are likewise grouped together in a separate sub-circuit. In addition, a superconductive switch is coupled with the superconducting assemblage. When a quench occurs, the current flow through the coil (main or bucking) that initiated the quench will be the same as the symmetric (main or bucking) coil with respect to the mid-plane because they are connected in the same sub-circuit. Though currents in different sub-circuits may be different, the symmetry or current balance is preserved in terms of the current in the two half magnets. Therefore the force, acting on each half structure and/or the main and bucking structures, will be minimized, resulting in a balanced quench.
In one aspect of the invention, at least two quench heater or quench resistor circuits are connected in parallel with the superconducting coil assemblage. In another aspect of the invention, at least one quench heater circuit and at least one quench resistor circuit are connected in parallel with the superconducting coil assemblage. The quench heater circuit includes a plurality of generally identical quench heaters connected in parallel. The quench resistor circuit includes a plurality of generally identical quench resistors connected in series or in parallel with each other.
In a further aspect, at least one quench heater is positioned in thermal contact with the main magnet coil portions. Likewise, at least one quench heater is positioned in thermal contact with the secondary magnet coil portions.
In another aspect, the magnet coils of the superconducting coil assembly are essentially completely in contact with a fluid cryogen and at least one temperature limiting circuit is connected in parallel with the superconducting coil assemblage.

GE Medical Systems Global Technology Company, LLC


Described is an process for producing uniform coatings on circular substrates that reduces the amount of coating required. The improved process includes the steps of applying the liquid coating material through a single opening of a dispenser having certain characteristics, in a pattern onto the center of a spinning substrate, and then radially moving the dispenser opening near to the edge of the substrate while maintaining the dispenser opening at a predetermined distance from the substrate surface for substantially the entire radius of the substrate providing uniform coverage. Also described are products produced by the process that are substantially free of cosmetic defects and may be photochromic.

The present invention relates to a process for producing uniform coatings on circular substrates and the coated substrates produced by the process. In particular, the present invention is directed to an improved spin and spray coating process that optimizes the use of coating materials. More particularly, the present invention relates to efficiently producing optical elements having uniform coatings or imbibed areas containing photochromic compounds. Further, the coated optical elements meet commercially acceptable xe2x80x9ccosmeticxe2x80x9d standards for optical coatings applied to optical elements, e.g., lenses.
Photochromic compounds exhibit a reversible change in color when exposed to light radiation involving ultraviolet rays, such as the ultraviolet radiation in sunlight or the light of a mercury lamp. Various classes of photochromic compounds have been synthesized and suggested for use in applications in which a sunlight-induced reversible color change or darkening is desired.
In recent years, photochromic articles, particularly photochromic plastic materials for optical applications, have been the subject of considerable attention. In particular, photochromic ophthalmic plastic lenses have been investigated because of the weight advantage they offer, vis-à-vis, glass lenses. Moreover, photochromic transparencies for vehicles, such as cars and airplanes, have been of interest because of the potential safety features that such transparencies offer.
Methods for producing uniform coatings on substrates have been disclosed in numerous patents. U.S. Pat. No. 3,494,326 describes a spin-coating machine that includes a sealed compartment and means for providing a pressure differential in the area of the spinning lens. The controlled withdrawal and flow of air around the spinning lens due to the pressure differential reportedly enables providing a uniform coating on certain elongated lens shapes.
U.S. Pat. No. 5,094,884 describes an apparatus for applying a uniform layer of a fluid material on a substrate by using a dispensing nozzle having a rectangular or oblong shaped opening. The fluid material is dispensed while the nozzle moves along a radial path inwardly from the peripheral edge of the substrate.
U.S. Pat. No. 5,246,499 describes a coating system for applying a scratch-resistant coating to plastic ophthalmic lenses. The coating station of this system includes a coating arm assembly having nozzles which can be moved radially inwardly and outwardly over spinning lenses to apply the coating solution.
U.S. Pat. No. 5,514,214 describes an apparatus for and method of applying a UV curable monomer to the surface of an ophthalmic lens or mold. The substrate is sprayed with a UV curable solution while spinning at a high rate of speed to achieve a uniform coating. The coated substrate is then moved to a curing chamber to polymerize the monomer on the lens or mold.
U.S. Pat. No. 5,571,560 describes a method of coating a substrate that minimizes waste using a proximity dispenser that dispenses a liquid coating in the form of a stream from nozzles placed from 5 to 10 mm above the substrate.
U.S. Pat. No. 5,685,908 describes an apparatus for coating multifocal lens elements. The coating solution is applied using a nozzle that may be tilted while the lens is spun about an axis offset from the geometric center.
U.S. Pat. No. 5,766,354 describes a spin-coating device having the means to position the substrate at a predetermined angle while the fluid coating is dropped onto the rotating substrate.
A process has now been discovered for coating a substantially circular substrate with a liquid coating material dispensed onto the surface of a spinning substrate through a dispenser positioned above the substrate surface in a pattern which forms a uniform coating and reduces the amount of coating required. The improved process comprises the steps of applying the liquid coating material through a single opening in the dispenser onto the substantial center of the spinning substrate, and then moving radially the dispenser opening to near to the edge of the substrate while maintaining the dispenser opening at a predetermined distance from the substrate surface for substantially the entire radius of the substrate.
The dispenser used in the process of the present invention is one that produces a pattern having greater than 90%, preferably greater than 95%, and more preferably, greater than 99% of the dispensed material within the boundaries of the pattern. The term xe2x80x9cpatternxe2x80x9d as used herein describes a cross-section of the droplets and/or fluidized stream dispensed from the nozzle in a plane perpendicular to the direction of the discharge from the nozzle. Typically, the pattern may have an outside diameter of 1.2 inches (3 cm) when the coating material is dispensed through a single opening at a distance of from 0.3 to 0.6 inches (0.76 to 1.52 cm) from the substrate. Preferably, the pattern has an outside diameter of up to 1 inch (2.54 cm) when the distance is from 0.37 to 0.5 in (0.94 to 1.27 cm) and more preferably, the pattern appears as a ring having an uncoated inside circular region of about 0.4 inches (1.0 cm). Any type of disperser that produces the desired pattern may be used.
Preferably, the dispenser used in the process of the present invention is a Select Coat(copyright) Slim Swirl Applicator fitted with a swirl nozzle. This dispenser is described in U.S. Pat. No. 5,336,320 and Customer Product Manual, Part 303776A from the Nordson Corporation, both of which are incorporated herein by reference. The diameter of the aforementioned swirl nozzle may range from at least 0.008 inches (0.02 cm) preferably, at least 0.016 inches (0.04 cm) and more preferably, at least 0.020 inches (0.05 cm) to not more than 0.050 inches (0.13 cm), preferably, not more than 0.040 inches (0.1 cm) and most preferably, not more than 0.030 inches (0.076 cm). The diameter of the swirl nozzle used may range between any combination of these values, inclusive of the recited values.
In addition to the single opening in the swirl nozzle for dispensing fluid, there are 12 air holes angled toward the fluid discharged from the nozzle. The amount of air supplied to the dispenser has an effect on the pattern formed. For example, a fluid stream forming amount of air under pressure, i.e., an amount of air that does not cause the atomization or formation of individual droplets, e.g., from 1 to 3 pounds per square inch (psi) (6.89xc3x97103 to 2.07xc3x97104 Newtons per meter2 (N/m2)) produces a coating pattern having a donut or ring-like pattern, whereas an atomizing amount of air pressure, e.g., greater than 10 psi (6.89xc3x97104 N/m2), produces a filled-in circular pattern.
In the process of the present invention, the dispenser is attached to a means for moving it vertically and horizontally, such as a robotic arm. The radial horizontal movement of the robotic arm may be accomplished using a telescopic movement or by using a fixed arm that swings in an arc over the spinning substrate. The angle at which the dispenser is maintained during application of the coating material ranges from perpendicular to the substrate to 45 degrees from perpendicular to the substrate.
A programmable logic controller (PLC) may be used to coordinate the movement of the dispenser, the supply of the coating material and the rotation of the substrate. In one contemplated embodiment, a controller is used to move the dispenser over the substantial center of the substrate, spin the substrate at a first speed to wet the surface, e.g., from 100 to 500 rpm, initiate the dispensing of coating material, move the dispenser radially from the center to the edge of the substrate while maintaining a distance of from 0.3 to 0.6 inches (0.76 to 1.52 cm) to the substrate surface, and spin the coated substrate at a second speed to form a uniform coating, e.g., from 500 to 3000 rpm. The controller may also direct the placement and removal of substrates from a substrate holder attached to means for rotating the substrate at variable speeds. Depending on the type of coating to be formed, all of the coating equipment may be placed in an enclosure in which the temperature, relative humidity and dirt level are controlled to optimize use of the coating material and minimize the potential for cosmetic defects. Regarding the dirt level, it is preferred that he coating operation take place in an environment having less than 100 dirt particles per cubic meter and more preferably, less than 10 dirt particles per cubic meter, i.e., a Class 10 environment.
In another contemplated embodiment, the procedure of the previous embodiment is followed except that dispensing of the coating material is started at the edge and moved radially toward the substantial center of the substrate.
In a further contemplated embodiment, the process of the present is used to apply a coating to a lens mold surface. Lens forming materials are then placed into the mold to form the lens. The coating adheres more strongly to the lens material than to the mold surface, such that a coated lens can be removed from the mold.
The process of the present invention may be used to form various coatings and layers on substrates, such as polymeric coatings or layers on optical elements, e.g., photochromic coatings on lenses or on the molds for making such lenses, photochromic coatings for imbibition or thermal transfer processes that imbibe or transfer the photochromic compounds from the surface of the substrate into the substrate, e.g., to a depth of from 1 to 250 microns from the surface, preferably, from 5 to 200 microns and more preferably from 10 to 150 microns, protective coatings such as hardcoats, e.g., abrasion resistant coatings, or antireflective coatings on polymeric substrates. It is also envisioned that the process of the present invention may be used to optimize the coating material used in processes involving the spin coating of any substantially circular substrate, particularly, substrates having a non-flat surface, e.g., a curved or uneven surface.
The polymeric coatings that may be applied by the process of the present invention include compositions resulting in thermoplastic or thermosetting coatings, which are described in the Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, Volume 6, pages 669 to 760, which description is incorporated herein by reference. The coating applied to the substrate may be a coating comprising at least one polymer obtained from a member selected from the group consisting of polyurethanes, aminoplast resins, polyanhydrides, alkoxyacrylamides, organosilanes, polyvinyl alcohol, poly(meth)acrylates, polyamide resins, epoxy resins, hydroxy (C2-C3) alkyl cellulose and poly(vinylpyrolidone). Preferably, the polymeric coating is a photochromic polymeric coating. Various additives such as dyes, leveling agents, flow control agents and other specific materials, which serve their intended purpose, may be added to the coating composition.
Photochromic compounds that may be utilized in the aforedescribed polymeric coatings that may be applied by the process of the present invention include organic photochromic compounds. These photochromic compounds may be incorporated, e.g., dissolved or dispersed, in the polymeric coating composition(s) used to prepare the coatings. The photochromic compounds may be used individually or in combination with other complementary photochromic compounds, i.e., organic photochromic compounds having at least one activated absorption maxima within the range of between about 400 and 700 nanometers, or substances containing same. Such photochromic compounds or mixtures of such photochromic compounds color when activated to an appropriate or desired hue.
More particularly, the organic photochromic compounds comprise:
(a) at least one photochromic organic compound having a visible lambda max of from 400 nanometers to 525 nanometers; and
(b) at least one photochromic organic compound having a visible lambda max of from greater than 525 nanometers to 700 nanometers.
Examples of suitable photochromic compounds for use in the polymeric coatings include benzopyrans, naphthopyrans, e.g., naphtho[1,2-b]pyrans and naphtho[2,1-b]pyrans, phenanthropyrans, quinopyrans, benzoxazines, naphthoxazines, spiro(indoline)pyridobenzoxazines and indeno-fused naphthopyrans disclosed in U.S. Pat. No. 5,645,767. Specific examples include the novel naphthopyrans of U.S. Pat. No. 5,658,501 and the complementary organic photochromic substances disclosed in this patent from column 11, line 57 through column 13, line 36. Other photochromic substances contemplated for use herein are the photochromic metal-dithizonates, e.g., mercury dithizonates which are described in, for example, U.S. Pat. No. 3,361,706; and fulgides and fulgimides, e.g. the 3-furyl and 3-thienyl fulgides and fulgimides, which are described in U.S. Pat. No. 4,931,220 at column 20, line 5 through column 21, line 38 and mixtures of the aforementioned suitable photochromic substances.
The disclosures relating to such photochromic compounds in the aforedescribed patents are incorporated herein, in toto, by reference. The photochromic coatings of the present invention may contain one photochromic compound or a mixture of photochromic compounds, as desired. Mixtures of photochromic compounds may be used to attain certain activated colors such as a near neutral gray or brown. Further discussion of neutral colors and ways to describe such colors is found in U.S. Pat. No. 5,645,767 column 12, line 66 to column 13, line 19.
The amount of the photochromic substances described herein to be used in the coating applied by the process of the present invention is an amount sufficient to produce a photochromic effect discernible to the naked eye upon activation. Generally such amount can be described as a photochromic amount.
The relative amounts of the aforesaid photochromic compounds used will vary and depend in part upon the relative intensities of the color of the activated species of such compounds, and the ultimate color desired. Generally, the amount of photochromic substance incorporated into the coating composition may range from 0.1 to 40 weight percent based on the weight of the solids in the coating composition. Preferably, the concentration of photochromic substances ranges from 1.0 to 30 weight percent, more preferably, from 3 to 20 weight percent, and most preferably, from 5 to 15 weight percent, e.g., from 7 to 14 weight percent.
The photochromic compound(s) described herein may be incorporated into the coating composition by dissolving or dispersing the photochromic substance within an individual component of or a mixture of the polymer-forming or polymeric coating composition; and/or by dissolving it in solvent before adding it to the coating composition. The photochromic polymeric coating may also be used as a transfer medium in a subsequent imbibition or permeation processing step. A process for incorporating a photochromic compound by thermal diffusion into a synthetic organic host material is described in U.S. Pat. No. 5,130,353 which is incorporated herein by reference.
The process of the present invention may be used to more efficiently produce uniform coatings on substantially circular substrates of any type such as, for example glass, ceramics, metals and polymeric organic materials. Preferably, the substrate is a polymeric organic material, particularly, thermoset and thermoplastic polymeric organic materials, e.g., thermoplastic polycarbonate type polymers and copolymers and homopolymers or copolymers of a polyol(allyl carbonate) used as organic optical materials.
It is typical to treat the surface of the substrate prior to using the process of the present invention for the purposes of cleaning the surface and promoting adhesion. When the photochromic coating is used to imbibe the substrate, methods for etching the substrate may be included to make the surface more receptive to the imbibition of photochromic compounds. Cleaning of the plastic surface may be accomplished by washing the surface with an aqueous solution of a detergent specifically designed for cleaning such plastics. The cleaning step may be done manually or in an automated unit such as a Westek Cleaning System.
Effective treatment techniques for plastics, such as those prepared from CR-39@ diethylene glycol bis(allyl carbonate) monomer or thermoplastic polycarbonate, e.g., a resin derived from bisphenol A and phosgene, include ultrasonic cleaning; washing with an aqueous mixture of organic solvent, e.g., a 50:50 mixture of isopropanol: water or ethanol: water; UV treatment; activated gas treatment, e.g., treatment with low temperature plasma or corona discharge, and chemical treatment such as hydroxylation, i.e., etching of the surface with an aqueous solution of alkali, e.g., sodium hydroxide or potassium hydroxide, that may also contain a fluorosurfactant. See U.S. Pat. No. 3,971,872, column 3, lines 13 to 25; U.S. Pat. No. 4,904,525, column 6, lines 10 to 48; and U.S. Pat. No. 5,104,692, column 13, lines 10 to 59, which describe surface treatments of polymeric organic materials.
The treatment used for cleaning the glass surfaces of lenses and lens molds will depend on the type of dirt present on the glass surface. Such treatments are known to those skilled in the art. For example, washing the glass with an aqueous solution that may contain a low foaming, easily rinsed detergent, followed by rinsing and drying with a lint-free cloth; and ultrasonic bath treatment in heated (about 50xc2x0 C.) wash water, followed by rinsing and drying. Pre-cleaning with an alcohol-based cleaner or organic solvent prior to washing may be required to remove adhesives from labels or tapes.
The process of the present invention may be used to apply a primer to the surface of the substrate before application of the polymeric coating composition. The primer serves as a barrier coating to prevent interaction of the coating ingredients with the substrate and vice versa, and/or as an adhesive layer to adhere the coating composition to the substrate. The use of protective coatings, some of which may contain polymer-forming organosilanes, as primers to improve adhesion of subsequently applied coatings has been described. In particular, the use of non-tintable coatings is preferred. Examples of commercial coating products include SILVUE 124 and HI-GARD coatings, available from SDC Coatings, Inc. and PPG Industries, Inc., respectively.
In addition, depending on the intended use of the coated article, it may be necessary to apply an appropriate protective coating(s), i.e., an abrasion resistant coating onto the exposed surface of the coating composition to prevent scratches from the effects of friction and abrasion. In some cases, the primer and protective coatings are interchangeable, i.e., the same coating may be used as the primer and the protective coating(s). Other coatings or surface treatments, e.g., a tintable coating, antireflective surface, etc., may also be applied to the cured coating using the process of the present invention or by another means. Coating operations may be done by a coater such as the SCS Spin Coater Model 6708 from Specialty Coating Systems, Inc.
The process of the present invention may be used to produce coatings of different thicknesses on substrates. This may be accomplished by applying and curing a single coating or by repeating this step until the desired thickness is obtained. The thickness of a singularly applied coating may range from at least a monomolecular layer, preferably, at least 1 micron, more preferably, at least 5 microns, and most preferably at least 15 microns to not more than 50 microns, preferably, not more than 40 microns, more preferably, not more than 30 microns and most preferably, not more than 25 microns. The thickness of the applied coating may range between any combination of these values, inclusive of the recited values. For example, the thickness of an applied coating may range from 18 to 22 microns.
Following application of the coating composition to the treated surface of the substrate, the coating is cured or dried, e.g., dried and heated to effect imbibition. Depending on the substrate and components selected for the polymeric coating composition, the coating may be cured or dried at temperatures ranging from 22 C. to 200xc2x0 C. When heating is required to obtain a cured coating or to dry the coating and cause the thermal diffusion of the photochromic into the substrate, temperatures of between 80xc2x0 C. and a temperature above which the substrate is damaged due to heating, e.g., 80xc2x0 C. to 200xc2x0 C., are typically used. For example, certain organic polymeric materials may be heated up to 135xc2x0 C. for a period of 1 to 16 hours in order to cure the coating or imbibe the photochromic without causing damage to the substrate. While a range of temperatures has been described for curing and imbibing the coated substrate, it will be recognized by persons skilled in the art that temperatures other than those disclosed herein may be used.
Additional methods for curing the photochromic polymeric coating composition include irradiating the coating with infrared, ultraviolet, visible, thermal, microwave, gamma or electron radiation so as to initiate the polymerization reaction of the polymerizable components in the coating. This may be followed by a heating step.
Preferably, the resulting cured coating meets commercially acceptable xe2x80x9ccosmeticxe2x80x9d standards for optical coatings. Examples of cosmetic defects of coated lens include non-uniformity of the coating thickness, orange peel, pits, spotting, inclusions, cracking, crazing, ribbing and wrinkling of the coating. Definitions of these and other such coating defects are found in the Paint/Coatings Dictionary by Federation of Societies for Coatings Technology, Philadelphia, which disclosure is incorporated herein by reference. Most preferably, the cured coatings prepared using the process of the present invention are substantially free of cosmetic defects.
Examples of polymeric organic materials that may be substrates for the process of the present invention are polymers, i.e., homopolymers and copolymers, of the monomers and mixtures of monomers disclosed in U. S. Pat. No. 5,658,501 from column 15, line 28 to column 16, line 17, which is incorporated herein by reference.
Examples of such monomers and polymers include: polyol(allyl carbonate)monomers, e.g., diethylene glycol bis(allyl carbonate), which monomer is sold under the trademark CR-39; polyol(meth)acryloyl terminated carbonate monomer; diethylene glycol dimethacrylate monomers; ethoxylated phenol methacrylate monomers; diisopropenyl benzene monomers; ethoxylated trimethylol propane triacrylate monomers; ethylene glycol bismethacrylate monomers; poly(ethylene glycol)bis methacrylate monomers; urethane acrylate monomers; poly(ethoxylated bisphenol A dimethacrylate); poly(vinyl acetate); poly(vinyl alcohol); poly(vinyl chloride); poly(vinylidene chloride); polyurethanes, polythiourethanes, thermoplastic polycarbonates, such as the carbonate-linked resin derived from bisphenol A and phosgene, which is sold under the trademark LEXAN; polyesters, such as the material sold under the trademark MYLAR; poly(ethylene terephthalate); polyvinyl butyral; and poly(methyl methacrylate), such as the material sold under the trademark PLEXIGLAS and mixtures thereof.
More particularly contemplated, is the use of the process of the present invention to produce photochromic polymeric coatings on optically clear polymerizates, i.e., materials suitable for optical applications, such as optical elements, e.g., plano and vision correcting ophthalmic lenses, windows, clear polymeric films, automotive transparencies, e.g., windshields, aircraft transparencies, plastic sheeting, etc. Such optically clear polymerizates may have a refractive index that may range from about 1.48 to about 1.75, e.g., from about 1.495 to about 1.66. Specifically contemplated are coated optical elements made of thermoplastic polycarbonates and thermoset polycarbonates having imbibed photochromic compounds.
Ophthalmic lens types that may be coated by the process of the present invention include finished single vision, semi-finished single vision, aspheric, progressive and segmented lenses such as bifocal and multifocal lenses. When applying an optical coating to a segmented lens, it may be necessary to spin the lens at an axis offset from the geometric center to avoid coating buildup at the segment line(s). Ophthalmic lenses having a base curvature less than 6 diopters are defined herein as low base lenses and lenses having a base curvature of 6 or higher are defined herein as high base lenses. The process of the invention may be used to coat lenses having a low or high base curvature. When coating high base lenses, the dispenser to substrate surface distance is within the desired range of 0.3 to 0.6 inch at least 90% of the time, more preferably, at least 95% of the time and most preferably, 99% of the time while moving over the substrate surface.
Most particularly contemplated, is the use of the process of the present invention to produce photochromic optical articles either having the photochromic polymeric coatings on the optical elements or using the photochromic polymeric coating to imbibe the photochromic compounds into the optical element. Coated articles may be prepared by sequentially applying to the optical element a primer, the photochromic polymeric composition and appropriate protective coating(s). The resulting cured coating preferably meets commercially acceptable xe2x80x9ccosmeticxe2x80x9d standards for optical coatings, and most preferably, is substantially free of cosmetic defects.
Optical elements having imbibed photochromic compounds may be prepared by applying to the optical element a photochromic polymeric coating by the process of the present invention, drying the coating, i.e., heating the coated substrate for a duration and intensity that should be sufficient to obtain thermal transfer (permeation) of the photochromic substances to the desired depth in the substrate, and removing the residual photochromic substances depleted coating thereby leaving a photochromic amount of the photochromic substance entirely disposed beneath the surface of the substrate.

Spin and spray coating process for curved surfaces


An arrangement for supporting a track chain having a track link, a first bushing mechanically coupled to the track link, and a second bushing mechanically coupled to the track link. The first bushing has a first center point C1 defined thereon. The second bushing has a second center point C2 defined thereon. The first center point C1 is spaced apart from the second center point C2 by a distance D1. The arrangement includes an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The point P1 is spaced apart from the point P2 by a distance D2.

This invention relates generally to track assemblies for track type work machines and, more particularly, to an idler wheel for a track type work machine.
Conventional track chain assemblies utilized on track type work machines typically include a track chain comprised of a plurality of links that are interconnected by laterally disposed track pins. A track bushing is commonly disposed about the pin and is secured to the links for relative rotation with respect to the pin. The bushing is adapted to engage a drive sprocket that propels the track chain assembly about a frame and ultimately provides the tractive force necessary to power the work machine over the ground to perform various work functions with a work implement (e.g. a bucket or a blade).
The bushing is typically a xe2x80x9crollerxe2x80x9d bushing and is not fixed to the links but rather is allowed to rotate about the pin relative to both the pin and the links. This is done to reduce the wear between the sprocket and the bushings which is known to be quite severe, especially in the abrasive conditions in which track type work machines commonly operate.
Another source of wear on a track chain assembly occurs on the links of the track chain as a result of the interaction of the links with an idler wheel. In particular, the links commonly have a wear rail defined on an inwardly directed surface that engages wear surfaces defined on the idler wheel mounted on the frame. As the track chain rotates about the frame in the above-described manner, the wear rails of the links are continually brought into contact with the wear surface of the idler wheel and are thus subjected to severe wear. This severe wear is increased as a result of continually bringing the generally planar surface of the wear rails into contact with the arcuate idler wheel wear surface. The aforementioned contact results in an arcuate wear pattern being formed on the wear rails of the links. This wear decreases the xe2x80x9clifexe2x80x9d of the track chain assembly and thus increases the maintenance cost of the work machine.
As shown in U.S. Pat. Nos. 1,112,460 and 1,228,709 some track assemblies utilize components which have teeth extending therefrom which facilitate the cooperation between the track chain and these components. However, these assemblies also suffer from several drawbacks. For example, the components having the teeth extending therefrom are positioned outside of the links and therefore are subject to damage from elements (e.g. rocks) present in the work environment of the track chain assembly.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
In accordance with one embodiment of the present invention, there is provided an arrangement for supporting a track chain having a track link, a first bushing mechanically coupled to the track link, and a second bushing mechanically coupled to the track link. The first bushing has a first center point C1 defined thereon. The second bushing has a second center point C2 defined thereon. The first center point C1 is spaced apart from the second center point C2 by a distance D1. The arrangement includes an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The point P1 is spaced apart from the point P2 by a distance D2. The distance D1 is greater than the distance D2.
In accordance with another embodiment of the present invention there is provided a track chain assembly. The track chain assembly includes a track link. The assembly also includes a first bushing mechanically coupled to the track link. The first bushing has a first center point C1 defined thereon. The assembly also includes a second bushing mechanically coupled to the track link. The second bushing has a second center point C2 defined thereon. The first center point C1 is spaced apart from the second center point C2 by a distance D1. The assembly further includes an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first bushing is positioned within the first notch. The second bushing is positioned within the second notch. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The point P1 is spaced apart from the point P2 by a distance D2. The distance D1 is greater than the distance D2.
In accordance with yet another embodiment of the present invention there is provided a track type work machine. The work machine includes a frame and a work implement mechanically coupled to the frame. The work machine also includes a track chain assembly mechanically coupled to the frame. The track chain assembly has (i) a track link, (ii) a first bushing mechanically coupled to the track link, the first bushing has a first center point C1 defined thereon, (iii) a second bushing mechanically coupled to the track link, the second bushing has a second center point C2 defined thereon, the first center point C1 is spaced apart from the second center point C2 by a distance D1, and (iv) an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first bushing is positioned within the first notch. The second bushing is positioned within the second notch. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The first point P1 is spaced apart from the second point P2 by a distance D2. The distance D1 is greater than the distance D2.

Arrangement for supporting a track chain of a track type work machine


A detergent composition comprising a xcex2-glucanase is presented. The xcex2-glucanase improves the cleaning performance of the detergent, especially with respect to polysaccharide soils.

1. Field of the Invention
This invention relates to laundry detergents which contain xcex2-glucanase to improve their cleaning performance.
2. Discussion of Related Art
Enzymes, especially proteases, lipases and cellulases, but also amylases, are widely used in laundry detergents, washing aids and dishwashing detergents. Proteases, lipases or amylases are primarily used to remove protein, fatty and starch soils. By contrast, cellulases occupy a special position because they are not used to remove special soils, but instead have been known for some time as softening agents for cotton fabrics by virtue of their ability to degrade cellulose. A side effect of the degradation of cellulose fibrils by cellulases is the deepening of the optical color impression, the so-called color freshening effect, which is obtained in the treatment of colored cotton fabrics with cellulases when the undyed fibrils resulting from fiber damage from within the fibers are removed.
In connection with polysaccharide soils, there is the problem that naturally occurring polysaccharides, for example as present in foods, do not normally consist solely of starch, but also contain other saccharides or differently linked saccharides. Whereas xcex1-amylases intended for use in laundry detergents are generally very suitable for hydrolyzing the starch component of polysaccharide soils into water-soluble oligosaccharides, their soil removal capacity can be unsatisfactory when the soils in question are soils of other polysaccharides or when these other polysaccharides make up relatively large parts of the polysaccharide soils.
The problem addressed by the present invention was to remedy this situation and to provide a detergent which would have an improved cleaning performance with respect to polysaccharide soils.
The present invention, which is intended to solve the problem stated above, relates to a detergent suitable for use in the washing of laundry which contains a xcex2-glucanase in addition to typical ingredients compatible with this enzyme.
xcex2-Glucanases in the context of the present invention are enzymes from the class of endo-1,3-1,4-xcex2-D-glucan-4-glucanohydrolases (EC 126.96.36.199; lichenases). xcex2-Glucanases in the context of the invention also include endo-1,3-xcex2-D-glucosidases (EC 220.127.116.11; laminarinases). xcex2-Glucanases cleave mixed glucans, which are linked alternately by 1,3- and 1,4-xcex2-glucoside bonds, into oligosaccharides. Polymeric mixed glucans such as these are present in varying amounts in virtually all cereal products. Hitherto, enzymes capable of cleaving them have been used above all in the food, beverage and animal feed industry, in the textile industry and in the processing of starch (R. Borriss, xe2x80x9cxcex2-Glucan-spaltende Enzymexe2x80x9d, in H. Ruttloff: xe2x80x9cIndustrielle Enzymexe2x80x9d, Chapter 11.5, Behr""s Verlag, Hamburg, 1994).
xcex2-Glucanases suitable for use in accordance with the invention are obtainable from microorganisms, for example Achromobacter lunatus, Athrobacter luteus, Aspergillus aculeatus, Aspergillus niger, Bacillus subtilis, Disporotrichum dimorphosporum, Humicola insolens, Penicillium emersonii, Penicillium funiculosum or Trichoderna reesei. A commercial product is marketed, for example, under the name of Cereflo(copyright) (manufacturer: Novo Nordisk A/S). Preferred xcex2-Glucanases include an enzyme obtainable from Bacillus alkalophilus (DSM 9956) which is the subject of German patent application DE 197 32 751.
xcex2-Glucanase is preferably incorporated in compositions according to the invention in such quantities that they have glucanolytic activities of 0.05 U/g to 1 U/g and more particularly in the range from 0.06 U/g to 0.25 U/g. The determination of the glucanolytic activity is based on modifications of the process described by M. Lever in Anal. Biochem. 47 (1972), 273-279 and Anal Biochem. 81 (1977), 21-27. A 0.5% by weight solution of xcex2-glucan (Sigma No. G6513) in 50 mM glycine buffer (pH 9.0) is used for this purpose. 250 xcexcl of this solution are added to 250 xcexcl of a solution containing the agent to be tested for glucanolytic activity and incubated for 30 minutes at 40xc2x0 C. 1.5 ml of a 1% by weight solution of p-hydroxybenzoic acid hydrazide (PAHBAH) in 0.5 M NaOH, which contains 1 mM bismuth nitrate and 1 mM potassium sodium tartrate, are then added, after which the solution is heated for 10 minutes to 70xc2x0 C. After cooling (2 minutes/0xc2x0 C.), the absorption at 410 nm is determined against a blank value at room temperature (for example with a Uvikon(copyright) 930 photometer) using a glucose calibration curve. The blank value is a solution which is prepared in the same way as the measuring solution except that the glucan solution is added after the PAHBAH solution. 1 U corresponds to the quantity of enzyme which produces 1 xcexcmole of glucose per minute under these conditions.
The present invention also relates to the use of xcex2-glucanase for removing polysaccharide soils from textiles and to a process for removing polysaccharide soils from textiles by using xcex2-glucanase. For the use according to the invention and for the process according to the invention, the xcex2-glucanase may be applied to polysaccharide-soiled textiles either on its own or as part of a laundry pretreatment composition in the course of a pretreatment step preceding the washing process. However, the xcex2-glucanase is preferably used as part of an aqueous cleaning solution which may additionally contain typical ingredients of wash liquors. Glucanolytic activities of 0.2 U/l to 4 U/l and, more particularly, 0.25 U/l to 1 U/l in the aqueous cleaning solution are preferred. In machine washing processes, for example in the routine washing of domestic laundry in washing machines, the glucanolytic activities mentioned do not have to be maintained over the entire washing cycle to achieve the required washing result providing it is guaranteed that a glucanolytic activity in the range mentioned prevails for at least a short time, for example for about 5 to 20 minutes.
xcex2-Glucanase may be adsorbed onto supports and/or encapsulated in shell-forming substances to protect it against premature inactivation, particularly where it is used in particulate detergents as described, for example, in European patent EP 0 564 476 or in International patent applications WO 94/23005 for other enzymes.
In the course of the development work on which the present invention is based, it was surprisingly found that, if desired, amylase need not be used at all with no significant loss of cleaning performance against polysaccharide soils consisting at least partly of starch.
Since the washing performance of proteolytic and xcex2-glucanolytic enzymes is unexpectedly increased when they are used in combination, a laundry detergent according to the invention preferably contains at least one protease in addition to xcex2-glucanase. A detergent according to the invention is distinguished in particular by a proteolytic activity of about 100 PU/g to about 7500 PU/g and, more particularly, in the range from 500 PU/g to 5000 PU/g. The protease activity is determined by the standardized method described in the following (cf. Tenside 7 (1970), 125): a solution containing 12 g/l casein and 30 mM sodium tripolyphosphate in water with a hardness of 15xc2x0dH (containing 0.058% by weight CaCl2.2H2O, 0.028% by weight MgCl2.6H2O and 0.042% by weight NaHCO3) is heated to 70xc2x0 C. and the pH is adjusted to 8.5 by addition of 0.1 N NaOH at 50xc2x0 C. 200 ml of a solution of the agent to be tested for proteolytic activity in 2% by weight sodium tripolyphosphate buffer solution (pH 8.5) are added to 600 ml of the substrate solution. The reaction mixture is incubated for 15 minutes at 50xc2x0 C. The reaction is then stopped by addition of 500 ml of TCA solution (0.44 M trichloroacetic acid and 0.22 M sodium acetate in 3% by volume acetic acid) and cooling (ice bath at 0xc2x0 C., 15 minutes). The TCA-insoluble protein is removed by centrifuging and 900 ml of the supernatant are diluted with 300 ml 2 N NaOH. The absorption of this solution at 290 nm is determined with an absorption spectrometer, the zero absorption value having to be determined by measuring a centrifuged solution prepared by mixing 600 ml of the above-mentioned TCA solution with 600 ml of the above-mentioned substrate solution and then adding the enzyme solution. The proteolytic activity of a solution which produces an absorption of 0.500 OD under the described measuring conditions is defined as 10 PU (protease units) per ml. The proteases preferably used in compositions according to the invention include the enzymes known from International patent applications WO 91/02792, WO 92/21760 and WO 95/23221.
Besides the xcex2-glucanase used in accordance with the invention, the detergents according to the inventionxe2x80x94which may be present as, in particular, powder-form solids, as post-compacted particles or as homogeneous solutions or suspensionsxe2x80x94may in principle contain any known ingredients typically encountered in detergents. More particularly, the detergents according to the invention may contain builders, surfactants, bleaching agents based on organic and/or inorganic peroxygen compounds, bleach activators, water-miscible organic solvents, additional enzymes, sequestering agents, electrolytes, pH regulators and/or other auxiliaries, such as optical brighteners, redeposition inhibitors, dye transfer inhibitors, foam regulators, dyes and perfumes.
The detergents according to the invention may contain one or more surfactants, more particularly anionic surfactants, nonionic surfactants and mixtures thereof. Suitable nonionic surfactants are, in particular, alkyl glycosides and ethoxylation and/or propoxylation products of alkyl glycosides or linear or branched alcohols containing 12 to 18 carbon atoms in the alkyl moiety and 3 to 20 and preferably 4 to 10 alkyl ether groups. Corresponding ethoxylation and/or propoxylation products of N-alkylamines, vicinal diols, fatty acid esters and fatty acid amides, which correspond to the long-chain alcohol derivatives mentioned in regard to the alkyl moiety, and of alkyl phenols containing 5 to 12 carbon atoms in the alkyl group are also suitable.
Suitable anionic surfactants are, in particular, soaps and those which contain sulfate or sulfonate groups with, preferably, alkali metal ions as cations. Suitable soaps are preferably the alkali metal salts of saturated or unsaturated fatty acids containing 12 to 18 carbon atoms. Fatty acids such as these may also be used in non-completely neutralized form. Suitable surfactants of the sulfate type include the salts of sulfuric acid semiesters of fatty alcohols containing 12 to 18 carbon atoms and sulfation products of the nonionic surfactants mentioned with a low degree of ethoxylation. Suitable surfactants of the sulfonate type include linear alkyl benzenesulfonates containing 9 to 14 carbon atoms in the alkyl moiety, alkanesulfonates containing 12 to 18 carbon atoms and olefin sulfonates containing 12 to 18 carbon atoms, which are formed in the reaction of corresponding monoolefins with sulfur trioxide, and xcex1-sulfofatty acid esters which are formed in the sulfonation of fatty acid methyl or ethyl esters.
Surfactants such as these are present in the detergents according to the invention in quantities of, preferably, 5% by weight to 50% by weight and, more preferably, 8% by weight to 30% by weight.
A detergent according to the invention preferably contains at least one water-soluble and/or water-insoluble organic and/or inorganic builder. The water-soluble organic builders include polycarboxylic acids, more particularly citric acid and sugar acids, monomeric and polymeric aminopolycarboxylic acids, more particularly methyl glycine diacetic acid, nitrilotriacetic acid and ethylenediamine tetraacetic acid, and polyaspartic acid, polyphosphonic acids, more particularly aminotris-(methylenephosphonic acid), ethylenediamine-tetrakis-(methylenephosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid, polymeric hydroxy compounds, such as dextrin, and polymeric (poly)carboxylic acids, more particularly the polycarboxylates obtainable by oxidation of polysaccharides or dextrins according to International patent application WO 93/16110 or International patent application WO 92/18542 or European patent EP 0 232 202, polymeric acrylic acids, methacrylic acids, maleic acids and copolymers thereof which may also contain small amounts of polymerizable substances with no carboxylic acid functionality in copolymerized form. The relative molecular weight of the homopolymers of unsaturated carboxylic acids is generally between 5,000 and 200,000 and that of the copolymers between 2,000 and 200,000 and preferably between 50,000 and 120,000, based on free acid. A particularly preferred acrylic acid/maleic acid copolymer has a relative molecular weight of 50,000 to 100,000. Suitable but less preferred compounds of this class are copolymers of acrylic acid or methacrylic acid with vinyl ethers, such as vinyl methyl ethers, vinyl esters, ethylene, propylene and styrene, in which the acid makes up at least 50% by weight. Other suitable water-soluble organic builders are terpolymers which contain two unsaturated acids and/or salts thereof as monomers and vinyl alcohol and/or an esterified vinyl alcohol or a carbohydrate as the third monomer. The first acidic monomer or its salt is derived from a monoethylenically unsaturated C3-8 carboxylic acid and preferably from a C3-4 monocarboxylic acid, more particularly from (meth)acrylic acid. The second acidic monomer or its salt may be a derivative of a C4-8 dicarboxylic acid, maleic acid being particularly preferred, and/or a derivative of an allylsulfonic acid substituted in the 2-position by an alkyl or aryl group. Polymers such as these may be produced by the processes described in German patent DE 42 21 381 and German patent application DE 43 00 772 and generally have a relative molecular weight of 1,000 to 200,000. Other preferred copolymers are those which are described in German patent applications DE 43 03 320 and DE 44 17 734 and which preferably contain acrolein and acrylic acid/acrylic acid salts or vinyl acetate as monomers. The organic builders may be used in the form of aqueous solutions, preferably in the form of 30 to 50% by weight aqueous solutions, especially for the production of liquid detergents. All the acids mentioned are generally used in the form of their water-soluble salts, more particularly their alkali metal salts.
If desired, organic builders of the type in question may be present in quantities of up to 40% by weight, preferably in quantities of up to 25% by weight and more preferably in quantities of 1% by weight to 8% by weight. Quantities near the upper limit mentioned are preferably used in paste-form or liquidxe2x80x94more particularly water-containingxe2x80x94detergents according to the invention.
Suitable water-soluble inorganic builders are, in particular, alkali metal silicates and polymeric alkali metal phosphates which may be present in the form of their alkaline, neutral or acidic sodium or potassium salts, Examples include tetrasodium diphosphate, disodium dihydrogen diphosphate, pentasodium triphosphate, so-called sodium hexametaphosphate, and the corresponding potassium salts or mixtures of sodium and potassium salts. Suitable water-insoluble, water-dispersible inorganic builders are, in particular, crystalline or amorphous alkali metal alumosilicates which are used in quantities of up to 50% by weight, preferably in quantities of not more than 40% by weight andxe2x80x94in liquid detergentsxe2x80x94more particularly in quantities of 1% by weight to 5% by weight. Of these, crystalline sodium alumosilicates in detergent quality, more particularly zeolite A, P and optionally X, are preferred. Quantities near the upper limit mentioned are preferably used in solid particulate detergents. Suitable alumosilicates above all contain no particles larger than 30 xcexcm in size, at least 80% by weight consisting of particles below 10 xcexcm in size. The calcium binding capacity, which may be measured in accordance with German patent DE 24 12 837, is generally in the range from 100 to 200 mg CaO per gram.
Suitable substitutes or partial substitutes for the alumosilicate mentioned are crystalline alkali metal silicates which may be present on their own or in admixture with amorphous silicates. The alkali metal silicates suitable as builders in the detergents according to the invention preferably have a molar ratio of alkali metal oxide to SiO2 below 1:0.95 and, more particularly, between 1:1.1 and 1:12 and may be present in amorphous or crystalline form. Preferred alkali metal silicates are the sodium silicates, more particularly the amorphous sodium silicates, with a molar Na2O:SiO2 ratio of 1:2 to 1:2.8. Those with a molar Na2O:SiO2 ratio of 1:1.9 to 1:2.8 may be produced by the process according to European patent application EP 0 425 427. Preferred crystalline silicates, which may be present on their own or in the form of a mixture with amorphous silicates, are crystalline layer silicates with the general formula Na2SixO2x+1.yH2O where xxe2x80x94the so-called modulusxe2x80x94is a number of 1.9 to 4 and y is a number of 0 to 20, preferred values for x being 2, 3 or 4. Crystalline layer silicates which fall within this general formula are described, for example, in European patent application EP 0 164 514. Preferred crystalline layer silicates are those in which x in the general formula shown above assumes the value 2 or 3. More particularly, both xcex2- and xcex4-sodium disilicates (Na2Si2O5.yH2O) are preferred, xcex2-sodium disilicate being obtainable, for example, by the process described in International patent application WO 91/08171. xcex4-Sodium silicates with a modulus of 1.9 to 3.2 may be produced in accordance with Japanese patent applications JP 04/238 809 and JP 04/260 610. Substantially water-free crystalline alkali metal silicates with the above general formula, where x is a number of 1.9 to 2.1, produced from amorphous alkali metal silicates as described in European patent applications EP 0 548 599, EP 0 502 325 and EP 0 452 428 may also be used in detergents according to the invention. Another preferred embodiment of detergents according to the invention is characterized by the use of a crystalline sodium layer silicate with a modulus of 2 to 3 which may be produced from sand and soda by the process according to European patent application EP 0 436 835. Crystalline sodium silicates with a modulus of 1.9 to 3.5 obtainable by the processes according to European patents EP 0 164 552 and/or EP 0 293 753 are used in another preferred embodiment of detergents according to the invention. Another preferred embodiment of detergents according to the invention is characterized by the use of the granular compound of alkali metal silicate and alkali metal carbonate which is described, for example, in International patent application WO 95/22592 or which is commercially obtainable, for example, as Nabion(copyright) 15. If alkali metal alumosilicate, especially zeolite, is also present as an additional builder, the ratio by weight of alumosilicate to silicate, expressed as water-free active substances, is preferably from 1:10 to 10:1. In detergents containing both amorphous and crystalline alkali metal silicates, the ratio by weight of amorphous alkali metal silicate to crystalline alkali metal silicate is preferably 1:1 to 2:1 and, more particularly, 1:1 to 2:1.
Builders are present in the detergents according to the invention in quantities of preferably up to 60% by weight and, more preferably, 5% by weight to 40% by weight.
Suitable peroxygen compounds are, in particular, organic peracids or peracidic salts of organic acids, such as phthalimidopercaproic acid, perbenzoic acid or salts of diperdodecane diacid, hydrogen peroxide and inorganic salts which release hydrogen peroxide under the washing conditions, such as perborate, percarbonate and/or persilicate. Hydrogen peroxide can also be produced by an enzyme system, i.e. an oxidase and its substrate. If solid peroxygen compounds are to be used, they may be used in the form of powders or granules which may also be coated in known manner. In a particularly preferred embodiment, alkali metal percarbonate, alkali metal perborate monohydrate, alkali metal perborate tetrahydrate or hydrogen peroxide is used in the form of an aqueous solution containing 3% by weight to 10% by weight of hydrogen peroxide. If a detergent according to the invention contains peroxygen compounds, the peroxygen compounds are present in quantities of preferably up to 50% by weight and, more preferably, 5% by weight to 30% by weight. The addition of small quantities of known bleach stabilizers, for example phosphonates, borates or metaborates and metasilicates and magnesium salts, such as magnesium sulfate, can be useful.
The bleach activators may be compounds which form aliphatic peroxocarboxylic acids containing preferably 1 to 10 carbon atoms and more preferably 2 to 4 carbon atoms and/or optionally substituted perbenzoic acid under perhydrolysis conditions. Substances bearing O- and/or N-acyl groups with the number of carbon atoms mentioned and/or optionally substituted benzoyl groups are suitable. Preferred bleach activators are polyacylated alkylenediamines, more particularly tetraacetyl ethylenediamine (TAED), acylated triazine derivatives, more particularly 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycolurils, more particularly tetraacetyl glycoluril (TAGU), N-acylimides, more particularly N-nonanoyl succinimide (NOSI), acylated phenol sulfonates, more particularly n-nonanoyl or isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic anhydrides, more particularly phthalic anhydride, acylated polyhydric alcohols, more particularly triacetin, ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydrofuran and the enol esters known from German patent applications DE 196 16 693 and DE 196 16 767, acetylated sorbitol and mannitol and the mixtures thereof (SORMAN) described in European patent application EP 0 525 239, acylated sugar derivatives, more particularly pentaacetyl glucose (PAG), pentaacetyl fructose, tetraacetyl xylose and octaacetyl lactose, and acetylated, optionally N-alkylated glucamine and gluconolactone, and/or N-acylated lactams, for example N-benzoyl caprolactam, which are known from International patent applications WO-A-94/27970, WO-A-94/28102, WO-A-94/28103, WO-A-95/00626, WO-A-95/14759 and WO-A-95/17498. The substituted hydrophilic acyl acetals known from German patent application DE 196 16 769 and the acyl lactams described in German patent application DE 196 16 770 and in International patent application WO 95/14075 are also preferably used. The combinations of conventional bleach activators known from German patent application DE 44 43 177 may also be used. Bleach activators such as these are present in the usual quantities, preferably in quantities of 1% by weight to 10% by weight and more preferably in quantities of 2% by weight to 8% by weight, based on the detergent as a whole.
In addition to or instead of the conventional bleach activators mentioned above, the sulfonimines known from European patents EP 0 446 982 and EP 0 453 003 and/or bleach-boosting transition metal salts or transition metal complexes may also be present as so-called bleach catalysts. Suitable transition metal compounds include, in particular, the manganese-, iron-, cobalt-, ruthenium- or molybdenum-salen complexes known from German patent application DE 195 29 905 and the N-analog compounds thereof known from German patent application DE 196 20 267, the manganese-, iron-, cobalt-, ruthenium- or molybdenum-carbonyl complexes known from German patent application DE 195 36 082, the manganese, iron, cobalt, ruthenium, molybdenum, titanium, vanadium and copper complexes with nitrogen-containing tripod ligands described in German patent application DE 196 05 688, the cobalt-, iron-, copper- and ruthenium-ammine complexes known from German patent application DE 196 20 411, the manganese, copper and cobalt complexes described in German patent application DE 44 16 438, the cobalt complexes described in European patent application EP 0 272 030, the manganese complexes known from European patent application EP 0 693 550, the manganese, iron, cobalt and copper complexes known from European patent EP 0 392 592, the cobalt complexes known from International patent applications WO 96/23859, WO 96/23860 and 96/23861 and/or the manganese complexes described in European patent EP 0 443 651 or in European patent applications EP 0 458 397, EP 0 458 398, EP 0 549 271, EP 0 549 272, EP 0 544 490 and EP 0 544 519. Combinations of bleach activators and transition metal bleach catalysts are known, for example, from German patent application DE 196 13 103 and from international patent application WO 95/27775. Bleach-boosting transition metal complexes, more particularly with the central atoms Mn, Fe, Co. Cu, Mo. V, Ti and/or Ru, are used in typical quantities, preferably in a quantity of up to 1% by weight, more preferably in a quantity of 0.0025% by weight to 0.25% by weight and most preferably in a quantity of 0.01% by weight to 0.1% by weight, based on the detergent as a whole.
Enzymes suitable for use in the detergents besides the xcex2-glucanase crucial to the invention and the oxidase mentioned above are those from the class of proteases, lipases, cutinases, amylases, pullulanases, cellulases, hemicellulases, xylanases and peroxidases and mixtures thereof, for example proteases, such as subtilisin BPNxe2x80x2, Properase(copyright), BLAP(copyright), Optimase(copyright), Opticlean(copyright), Maxatase(copyright), Maxacal(copyright), Maxapem(copyright), Alcalase(copyright), Esperase(copyright), Savinase(copyright), Durazym(copyright), Everlase(copyright) and/or Purafect(copyright) G or OxP; amylases, such as BAN(copyright), Termamyl(copyright), Amylase-LT(copyright), Maxamyl(copyright), Duramyl(copyright) and/or Purafect(copyright)OxAm; lipases, such as Lipolase(copyright), Lipomax(copyright), Lumafast(copyright) and/or Lipozym(copyright); cellulases, such as KAC(copyright), Celluzyme(copyright), Carezyme(copyright), and/or the enzymes known from International patent applications WO 96/34108 and WO 97/13862. Enzymes obtained from fungi or bacteria, such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus, Humicola lanuginosa, Humicola insolens, Pseudomonas peudoalcaligenes or Pseudomonas cepacia are particularly suitable. The additional enzymes optionally used may also be adsorbed to supports and/or embedded in shell-forming materials for protection against premature inactivation, for example as described in European patent 0 564 476 or in International patent application WO 94/23005. They are present in the detergents according to the invention in quantities of preferably up to 10% by weight and, more preferably, from 0.2% by weight to 2% by weight, enzymes stabilized against oxidative degradation, as known for example from International patent applications WO 94/02597, WO 94/02618, WO 94/18314, WO 94/23053 or WO 95107350, being particularly preferred. In one particularly preferred embodiment of the invention, the detergent may be amylase-free or contains at least minimal amounts of amylase because the use of xcex2-glucanase generally enables even amylolytically removable soils on textiles to be removed without any significant loss of performance
The organic solvents suitable for use in the detergents according to the invention, particularly where they are present in liquid or paste-like form, include C1-4 alcohols, more especially methanol, ethanol, isopropanol and tert. butanol, C2-4 diols, more especially ethylene glycol and propylene glycol, and mixtures thereof and ethers derived from the classes of compound mentioned. Water-miscible solvents such as these are present in the detergents according to the invention in quantities of preferably not more than 30% by weight and, more preferably, between 6% by weight and 20% by weight.
To establish a desired pH value which is not spontaneously adjusted by the mixture of the other components, the detergents according to the invention may contain system-compatible and environmentally compatible acids, more particularly citric acid, acetic acid, tartaric acid, malic acid, lactic acid, glycolic acid, succinic acid, glutaric acid and/or adipic acid and also mineral acids, more especially sulfuric acid, or bases, more especially ammonium or alkali metal hydroxides. pH regulators such as these are present in the detergents according to the invention in quantities of preferably not more than 20% by weight and, more preferably, between 1.2% by weight and 17% by weight.
The dye transfer inhibitors suitable for use in detergents according to the invention, more particularly laundry detergents, include in particular polyvinyl pyrrolidones, polyvinyl imidazoles, polymer N-oxides, such as poly-(vinlylpyridine-N-oxide) and vinyl pyrrolidone/vinyl imidazole copolymers.
The function of redeposition inhibitors is to keep the soil detached from the hard surfaces and particularly from the textile fibers suspended in the wash liquor. Suitable redeposition inhibitors are water-soluble, generally organic colloids, for example starch, glue, gelatine, salts of ether carboxylic acids or ether sulfonic acids of starch or cellulose or salts of acidic sulfuric acid esters of cellulose or starch. Water-soluble polyamides containing acidic groups are also suitable for this purpose. Other starch derivatives than those mentioned above, for example aldehyde starches, may also be used. Cellulose ethers, such as carboxymethyl cellulose (sodium salt), methyl cellulose, hydroxyalkyl cellulose, and mixed ethers, such as methyl hydroxyethyl cellulose, methyl hydroxypropyl cellulose, methyl carboxymethyl cellulose and mixtures thereof, are preferably used, for example in quantities of 0.1 to 5% by weight, based on the detergent.
The detergents may contain derivatives of diaminostilbene disulfonic acid or alkali metal salts thereof as optical brighteners. Suitable optical brighteners are, for example, salts of 4,4xe2x80x2-bis-(2-anilino-4-morpholino-1,3,5-triazinyl-6-amino)-stilbene-2,2xe2x80x2-disulfonic acid or compounds of similar structure which contain a diethanolamino group, a methylamino group and anilino group or a 2-methoxyethylamino group instead of the morpholino group. Brighteners of the substituted diphenyl styryl type, for example alkali metal salts of 4,4xe2x80x2-bis-(2-sulfostyryl)-diphenyl, 4,4xe2x80x2-bis-(4-chloro-3-sulfostyryl)-diphenyl or 4-(4-chlorostyryl)-4xe2x80x2-(2-sulfostyryl)-diphenyl, may also be present. Mixtures of the brighteners mentioned may also be used.
Particularly where the detergents are used in washing machines, it can be of advantage to add typical foam inhibitors to them. Suitable foam inhibitors are, for example, soaps of natural or synthetic origin which have a high percentage content of C18-24 fatty acids. Suitable non-surface-active foam inhibitors are, for example, organopolysiloxanes and mixtures thereof with microfine, optionally silanized, silica and also paraffins, waxes, microcrystalline waxes and mixtures thereof with silanized silica or bis-stearyl ethylenediamide. Mixtures of different foam inhibitors, for example mixtures of silicones, paraffins and waxes, may also be used with advantage. The foam inhibitors, more particularly silicone- and/or paraffin-containing foam inhibitors, are preferably fixed to a granular water-soluble or water-dispersible support. Mixtures of paraffins and bis-stearyl ethylenediamides are particularly preferred.
The production of solid detergents according to the invention does not involve any difficulties and may be carried out in known manner, for example by spray drying or granulation, the xcex2-glucanase and other enzymes, if any, and any other heat-sensitive ingredients, for example bleaching agents, optionally being separately added at a later stage. Detergents according to the invention having a high bulk density, more particularly in the range from 650 g/l to 950 g/l, are preferably produced by the process comprising an extrusion step which is known from European patent EP 486 592. Another preferred method of production is granulation as described in European patent EP 0 642 576. Liquid or paste-form detergents according to the invention in the form of solutions containing typical solvents are generally produced simply by mixing the ingredients which may be introduced into an automatic mixer either as such or in the form of a solution.


An automatic label printing and application system applies a custom label at a dynamically determined location on articles being moved along a conveyer. The system includes a bar code scanning system, preferably a group of bar code scanners each arranged to read at an assigned elevation above the conveyer belt. This configuration allows the system controller to generally determine the vertical height of pre-printed bar code on the article. The system uses photoelectric sensors to detect articles being moved along the conveyer, as well as an encoder and bar code scanning data to determine the horizontal position of the pre-printed bar code on the surface of the article. In this manner, the system dynamically determines both the vertical and horizontal position of the pre-printed bar code on the surface of the article. The system further includes a series of label printing and application stations that are configured to print customized labels on the surface of the article in a horizontal and vertical position to cover the pre-printed bar code, at least partially. In general, the stations are adjusted to apply labels at different elevations above the conveyer belt. The application elevation of labels is selected by selecting the appropriate label printing and application stations. The horizontal position of the label on the article is determined by coordinating encoder pulses in response to signals from photoelectric sensor for the respective label printing and application unit. The system also preferably includes a verification bar scanner at the downstream end to verify that an accurate label has been properly positioned on the article.

This invention relates to bar code labeling systems, and in particular to a bar code labeling system that prints and applies a bar code label to articles being conveyed on a conveyer belt. More specifically, the invention detects the location of pre-printed bar code labels on an assortment of articles being transported on a conveyer belt in single file, and prints and applies another label to the article covering the pre-printed bar code label.
In large distributions applications, sortation conveying systems are typically used to fulfill orders of intermingled articles such as assortments of books, video cassette containers, packaged software, compact disc containers, etc. Workers load items into the system and the articles are conveyed in single file within individual pockets on a core conveyer belt for the sortation conveying system. As the assorted articles begin to move through the system on the core conveyer belt, the system reads pre-printed bar code information on each respective article. This bar code information is transmitted to a system controller that instructs the system with respect to further downstream processing and sorting of the articles into the various outgoing orders.
It is typical for a conveyer sortation system to include label printing and application stations along the core conveyer belt upstream of the stacking stations for the outgoing orders. Typically, the post-applied label is custom generated for the specific article after the pre-printed bar code on the article is read. The post-applied label sometimes contains another bar code specific to the company operating the sortation conveying system for use at check out, and also often contains tracking or other information pertinent to the product. In many cases, the post-applied bar code label is affixed to the article in a location different from the location of the pre-printed bar code on the article. This presents a situation in which two bar codes are present on the article, one of which is pre-printed and the other of which is post-applied. The presence of two bar codes on an article can, however, lead to confusion for check-out workers, and can also lead to improper tracking and inventory data monitoring. In some circumstances, it is therefore desirable for the post-applied label to cover the pre-printed bar code on the article.
The invention is an automatic overlabeling system that dynamically senses the location of a pre-printed bar code on an article, and custom prints and applies another label on the article covering the pre-printed bar code. Normally, xe2x80x9cbar codexe2x80x9d will be printed on the applied label. In this manner, only a single bar code is present on the article, and thus confusion by retail check-out workers or other workers using bar code scanners is alleviated.
The system dynamically determines the location of the pre-printed bar code on each respective article being moved along the core conveyer for a sortation conveying system. This is accomplished at a rate of approximately 250 articles per minute. The system includes a bar code scanning system which normally consists of a plurality of bar code scanners, each assigned to read along an assigned orientation in an assigned region above the conveyer in search of pre-printed bar code information on articles being moved along the conveyer. A typical system would have five such bar code scanners. Two linear scanners are used to read ladder orientated bar code. Three raster scanners are used to read picket fence orientated bar code. The system also includes a series of label printing and application stations, preferably six. Each is adjusted to apply labels at a specific elevation on the surface of articles being moved along the conveyer. The label printing and application stations are located downstream from the bar code scanners. Each label printing and application station preferably includes a photoelectric sensor that senses the presence of article being conveyed into the station, as well as a microprocessor or station controller. The system also includes an overall system controller, preferably a PC, which controls the bar code scanners, creates a label format data for the label printing and application stations, and determines which station is to be used to print and apply the label on the respective article. The system also preferably includes a photoelectric sensor located at the input of the system to detect a presence of articles entering the system, as well as an encoder that monitors movement of the conveyer to provide article position tracking data. The system controller inputs a signal from the system photoelectric sensor as well as data signals from the bar code scanners and outputs control signals to the micro-controllers for the various label printing and application stations. Based on the information gathered by the system photoelectric sensor and the bar code scanners, the system controller calculates the vertical and horizontal position at which the label should be applied on the respective article. This information is transmitted to the label printing and application stations. In turn, the appropriate label printing and application station applies a label to the surface of the article at a location that covers at least a portion of the surface on which the pre-printed bar code is located.
The system preferably operates in the following manner. Articles are moved along the conveyer in single file. As an article enters the system, it is sensed by the photoelectric sensor and tracked by the system controller using data from the conveyer encoder. The data from the encoder is also transmitted to the controllers for the various label printing and application stations. The system controller tracks all the articles passing through the system individually. When the system photoelectric sensor senses that an article is entering the system, the system controller instructs the bar code scanners to read the moving article. The bar code scanners transmit the following information to the system controller: 1) any decoded bar code data that has been read, 2) data on the position of the bar code label on the article, and 3) data on the length of the article. The system controller is pre-programmed with the mounting location of each bar code scanner. Based on this information, the system controller is programmed to select the appropriate label printing and application station for printing and applying the label to the article. As mentioned, each label printing and application station is adjusted to apply labels at a specific height on the surface of articles being moved along the conveyor. The system controller then transmits control signals to the appropriate label printing and application station, regarding both the required label format data and position information. As mentioned, each label printing and application station has a dedicated station controller (e.g. microprocessor) which receives the control signals from the system controller. The station controller processes the data sent by the system controller and calculates the correct horizontal (i.e., machine direction) label position location on the article. If the dynamically determined new label location is such that part of the new label would over hang or otherwise not be fully attached to the article surface, the station controller automatically adjusts the new label location data to ensure that the label is placed entirely on the article. When an article is detected by a photoelectric sensor for the appropriate label printing and application station, the station controller determines whether it has been instructed to label the article. If the station was not instructed to label the article, the article passes without being labeled to subsequent label printing and application stations. If the station was instructed to label the article, the station controller instructs the station to apply the printed label when the article is in the correct horizontal position relative to the label printing and application unit.
In the preferred system, there are six label printing and application units. Three of the label application and printing units are adjusted to apply labels to the surface of article being moved along the conveyer at a first defined elevation above the conveyer, normally the lowermost region. Two of the label printing and application units are adjusted to apply labels at a second defined elevation above the conveyer, which is positioned higher than the first defined elevation. One of the label printing and application units is adjusted to apply labels on the surface of articles being moved along the conveyer at a third defined elevation. The third elevation is higher than the second and first defined elevations. This configuration is preferred because it is more likely that pre-printed bar code information appears on the surface of articles at the lower elevations, whereas less are located at the middle or higher elevations. In addition, some articles being conveyed through the system may not even have sufficient height to extend upward into the adjusted position for the highest label printing and application unit.
The above-described process is repeated for all articles entering into the system. The system is designed to be able to accommodate multiple articles each having assorted dimensions being conveyed through the system in single file. Preferably, a system in accordance with the invention can process information relating to multiple articles concurrently such that as one or more articles are being labeled, other articles may have entered the system and be in various stages of tracking and calculating information for the respective article.


This disclosure generally relates to the generation of a packet signature for packets determined to correspond to a network attack, such as a denial of service (“DoS”) attack. Specifically, a set of data packets captured during normal system operations can be analyzed to determine a set of baseline attributes. Additional packets captured during an attack can be compared to the baseline attributes, to determine, for individual packets, a probability that the packet forms a part of the attack. A packet signature can then be generated to identify attributes that are characteristic of the attack. That signature can then be used to filter out packets and mitigate the attack.

A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer or network resource unavailable to its intended users. Generally, DoS attacks consists of the concerted efforts of a person, or multiple people to prevent a network site or service from functioning efficiently or at all, temporarily or indefinitely. Targets of DoS attacks can include sites or services hosted on high-profile web servers such as cloud computing providers, e-commerce sites, banks, credit card payment gateways, and root name servers.
One common method of attack involves saturating the target machine with external communications requests, such that it cannot respond to legitimate traffic, or responds so slowly as to be rendered effectively unavailable. Such attacks usually lead to a server overload. In general terms, DoS attacks are implemented by either forcing the targeted computer(s) to reset, or consuming its resources so that it can no longer provide its intended service or obstructing the communication media between the intended users and the victim so that they can no longer communicate adequately.

This patent is subject to a terminal disclaimer.