A filtering method and apparatus pass the suspension (e.g. green liquor) to be filtered in a falling film down a first side of a filtering surface of a filter element at a different (higher) pressure than a second side, so that due to the pressure difference prevailing across the filtering surface the filtrate flows through the filtering surface and separated solids substantially remain in the suspension, without forming an undesirable solids layer on the filtering surface. A uniform liquid film falling on the filtering surface is generated by recirculating suspension from the bottom of the filter housing to an upper portion of the filter element. Nozzles may direct flow toward the filtering surface in localized areas. The method may be practiced continuously or in batches.

The present invention relates to a method of filtering suspension and an apparatus for realizing that method. The present invention may be applied for filtering green liquor containing finely divided matter, generated, for example, in the chemical circulation of a cellulose pulp mill.
A significant subprocess in the manufacture of sulphate cellulose pulp is the recovery of cooking chemicals. Part of the regeneration is formed by the manufacture of white liquor by causticizing, so that lime milk and green liquor are allowed to react in order to form lime sludge and white liquor. The green liquor is generated when a chemical melt containing sodium chemicals is led from the bottom of the furnace of a soda recovery boiler to a separate dissolving vessel, in which the melt is dissolved in a dilute liquor. The most significant sodium chemicals of the green liquor are sodium carbonate and sodium sulphide. The green liquor also contains insoluble compounds, such as metal oxides, silicates, soot and other impurities. The dregs containing impurities must be discharged from chemical circulation, since the dregs otherwise concentrate in the chemical circulation and disturb the manufacture of white liquor by causticizing. The cleaning of green liquor is generally performed in clarifiers. When the mills become larger and the environmental regulations more stringent cleaning by sedimentation principle results in large apparatus, the diameters of which exceed 30 meters. Moreover, clarifiers are always liable to disturbances, so that green liquor that is insufficiently pure may result even when correctly dimensioned apparatus is used.
An alternative method is to clean green liquor by filtering. Since the dregs mainly consist of finely divided matter, the filterability of which is poor and which rapidly clog the filtering surface, this method employs a filtering apparatus which has a large surface area and is thus expensive. A cake containing fine particles must thus often be removed from the filtering surface so that the filter remains efficient. When such a cake is washed off, a very dilute sludge is obtained, which must be further concentrated in several process stages.
In order to improve the filterability of, for example, lime sludge obtained from the causticizing process, a filtration aid may be used, by means of which a filtering layer having good filtering capacity when filtering finely divided green liquor is formed on the surface of the filter element. This procedure, however, results in additive costs and in an increased amount of waste being transported to a landfill site.
The filterability of a suspension, which is difficult to filter, has also been suggested to be improved in such a way that the formation of a filter cake on the filtering surface is prevented by removing separated solids by causing a strong shear force on the suspension close to the filtering surface, which mixes solids back to the suspension to be filtered. The problem with this cross-flow filtration has been the need to use large liquid volumes to be circulated in order to generate sufficient velocity and turbulence to remove the separated solids from the filtering area.
The purpose of the present invention is to provide a filtering method and apparatus, by which the disadvantages discussed above may be eliminated. The present invention provides a simpler and more economical method and apparatus for filtering liquid-solids suspensions, especially those which have so far been difficult to filter. Although the background of the problem has been discussed above in view of green liquor and the invention is particularly applicable thereto, it is only an example and the invention may be applied for filtering other liquid-solids suspensions, such as kaolin sludge, clarified white liquor, soda liquor, bleaching effluent of cellulose pulp production, liquids containing pulp fines at pulp mills, and liquids containing metal hydroxides.
In the filtering method of the invention the suspension to be filtered is brought into contact with the filtering surface of the filter element in a manner such that due to the pressure difference across the filtering surface the filtrate flows through the filtering surface and the separated solids substantially remain in the suspension. It is a characteristic feature of the invention that the suspension to be filtered is caused to flow downwardly on the filtering surface, so that filtration takes place from the film flowing on the filtering surface.
An apparatus in accordance with the present invention comprises a plurality of filter elements; the filtrate flows through the filtering surface of each while the separated solids substantially remain in the suspension, so that the filter is provided with at least a structure for passing the suspension to be filtered to the filtering surfaces and for removing the filtrate. It is a characteristic feature of the invention that the structure for passing the suspension to be filtered are positioned in such a way that the suspension is brought to an upper portion of each filtering surface to flow downwardly on the filtering surface. According to one preferred embodiment a filter is provided with means for recirculating the non-filtered suspension to an upper portion of the filtering surface.
The present invention realizes cross-flow filtration in a novel manner, such that shear forces preventing generation of solids cake on the filtering surface are formed by passing suspension to be filtered down the filtering surface to flow due to the gravitational force during filtration. Due to a pressure difference between different sides of the filtering surface part, of the liquid is filtered from the falling film through the filtering surface.
A continuous downwardly flowing liquid film is most suitably generated by recirculating non-filtered suspension to an upper portion of the filtering surface and the suspension to be filtered is supplied to and mixed with the circulation flow. The generation of a uniform liquid film on the filtering surface requires rather large liquid volumes (flow rates), generally larger than the amount of liquid which typically flows into the apparatus, therefore the recirculation of the suspension is highly desirable for efficient filtration.
Filter elements according to the present invention are preferably in the form of lamellas, tubes and/or discs. Usually the filtrate is discharged through a filter channel inside the element, such as a tube. If desired, the suspension to be filtered may be passed into the element, so that the filtration takes place in an opposite direction.
The separated solids tend to accumulate on the filtering surface. By maintaining the flow velocity high enough the generation of the solids layer may be completely prevented, since separating solid particles are entrained with the falling liquid. If a solids layer appears to be generating, it may be prevented or removed by lowering the pressure difference across the filter surface for a short period of time (e.g. a few minutes) so that the flow through the filtering surface ends or slows down and the "grip" of the layer from the filtering surface loosens, and when the downward flow loosens it, it flows with the suspension. In order to remove the harmful solids cake the volume of flow in the falling film may be intensified locally (e.g. in one or more restricted areas at a time); the increase of the flow may be generated by means of one or more liquid jets, for example.
The attachment of solids on the filtering surface may also be prevented by vibration using known mechanical or acoustical vibrating equipment.
The suspension to be filtered is typically distributed on the filtering surface in the same way as in conventional falling film evaporators, such as those sold by A. Ahlstrom Corporation of Helsinki, Finland. The suspension to be filtered is fed to a liquid distribution tray--having a bottom with evenly spaced perforations (openings)--mounted above the filter surfaces, and flows from the tray evenly over the filter.
The pressure difference across the filtering surface may be generated by joining the filter to conventional vacuum generating apparatus, such as a vacuum pump. The filter elements may thereby be assembled in an atmospheric pressure vessel or completely open to the atmosphere.
A required pressure difference may alternatively or additionally be maintained by pressurizing a filter in a pressure vessel with gas. The gas may be provided in a closed circulation system. The applied gas may be inert or reactive relative to the suspension to be filtered. Reactive gas is added, when so desired, during the filtration in order to realize desired chemical reactions.
Gas which might penetrate the filtering surface may be separated from the filtrate either in the filter element itself by removing it from a separate conduit than the filtrate, or (more preferably) from above the liquid surface through the upper part of the element, or in a separate vessel outside and distinct from the filter.
The filtration may take place either continuously or in batches. In continuous filtration new suspension is supplied, and thickened suspension is discharged, continuously. If however, dregs as clean as possible are desired (which for green liquor means efficient alkali removal from the dregs), it is possible to perform the filtration in batches.
In batch processes non-filtered suspension is not discharged continuously, but the feed of the suspension is stopped during filtration and the suspension is allowed to be thickened by recirculating. Thereafter wash water is supplied to the filter and filtration continues. The wash water, which mixes with the dregs, removes impurities (e.g. alkali) from the dregs. At the same time the water penetrating the filtering surface washes the filtering surface improving the filtration capacity. The dregs are removed as sludge to be further treated and a new filtration cycle may be begun.
An even more efficient treatment of dregs is provided, if a dregs cake is formed for washing. The apparatus according to the invention may be provided with a separate sludge vessel. A recirculation pump draws the suspension to be recirculated from the sludge vessel (to which the sludge flows from the bottom of the filter). The process is initiated by filling the sludge vessel with virgin suspension to be filtered, whereafter the recirculation and filtration of the suspension is started. Sludge from the filter is not removed from the sludge vessel, but rather is allowed to thicken there, which takes place when liquid is removed as filtrate. When the solids content of the sludge is at the desired level, the bottom conduit of the filter is closed and the filter is allowed to be filled with sludge. The pressure difference across the filter surface still prevails in a full filter, whereby liquid infiltrates through the filtering surface, on which a solids cake is generated. After filtration the sludge remaining between the filter elements or otherwise in the filter housing is removed and brought back to the sludge vessel. When the bottom of the filter is closed, a dregs cake remains due to the pressure difference on the surface of the elements. The gas flowing through the cake and the filter element removes humidity, drying the dregs cake. The generated cake is removed by washing with water and blowing with gas to be passed for further treatment (washing and drying). This entire procedure provides for very efficient treatment of dregs by the formation of a dregs cake.
In connection with a batch process as described above it is possible to carry out dregs washing with very efficient displacement washing techniques. In the art it has been typically necessary to carry out the dregs washing in separate apparatus. Washing according to the invention takes place by filling the filter housing with water after the dregs cake is dried, and then by discharging the filtered water to a washing water vessel. The cake is finally removed, as above, by washing with water and blowing with gas and the dregs-water mixture is passed from the filter housing to further treatment. The dried cake may alternatively be removed from the open bottom of the filter housing simply by blowing with air or other gas.
Thus, if so desired, according to the invention the entire treatment of the material to be filtered (such as green liquor) may be performed in the same apparatus (filter housing).
In batch process it is possible to adjust the capacity by pressure difference or by extending the interval between the cycles.
According to one aspect of the present invention, a method of filtering a suspension of solids in a liquid, using a filter surface having first and second sides and a generally vertical orientation, is provided. The method comprises the steps of (a) Causing the suspension to flow in a falling film down the first side of the filter surface. (b) Providing a higher gas pressure on the first side of the filter surface than on the second side of the filter surface, so that filtrate passes through the filter surface to the second side of the filter surface, while solids remain in the liquid flowing down the filter surface first side. (c) Withdrawing the filtrate away from the filter surface. And, (d) withdrawing the liquid with suspended solids away from the filter surface.
Step (b) may be practiced by supplying gas under superatmospheric pressure to the first side of the filter surface and/or by applying a partial vacuum to the second side of the filter surface. Partial vacuum and gas pressurization may be provided by using a vessel having an inlet, outlet, gas volume, and a compressing device connected to the outlet, in which case step (b) is practiced by causing gas from the second side of the filter surface to pass into the vessel through the vessel inlet, to pass out of the vessel through the vessel outlet, to be compressed by the gas compressing device, and then to pass toward the first side of the filter surface. The filter surface has a top and a bottom and step (a) is typically practiced by recirculating the liquid from step (d) from adjacent the bottom to adjacent the top, to flow in a falling film down the filter surface. The gas that is supplied may be gas that is inert to the suspension, or chemically reacts with the suspension.
Then there may be the further step (e) of locally intensifying rate or volume of falling film flow of suspension over the first side of the filter surface so as to substantially preclude the formation of a solids cake on the filter surface. Step (e) may be practiced by directing one or more liquid jets toward the filter surface first side. Alternatively, the prevention of the formation of a solids cake may be practiced by at least occasionally vibrating the filter surface either mechanically or acoustically.
Steps (a) through (d) may be practiced continuously or in batches, and where the suspension being filtered is green liquor the ratio of the flow velocity V to the average filtrate flow velocity V.sub.s through the filter surface is at least 5:1 (preferably about 8:1). During batch filtration, in which there is continuous recirculation but no introduction of virgin suspension, the dregs may be washed in the filter housing, and/or the dregs may be removed dry by blowing air or other gas through the inside of the filter elements to force the dregs cake to the bottom of the filter vessel from which it can be removed by opening the bottom of the vessel.
According to another aspect of the invention, a method of cleaning green liquor using a filter surface having first and second sides and a generally vertical orientation, is provided. The method comprises the steps of: (a) Causing the green liquor to flow in a falling film down the first side of the filter surface. (b) Providing a higher gas pressure on the first side of the filter surface than on the second side of the filter surface, so that filtrate passes through the filter surface to the second side of the filter surface, while solids remain in the liquid flowing down the filter surface first side. (c) Withdrawing the filtrate away from the filter surface. And, (d) withdrawing the green liquor away from the filter surface.
According to another aspect of the present invention a filtering apparatus is provided comprising the following components: A housing. A plurality of filter elements generally vertically mounted in the housing, and including a top and a bottom. Each filter element comprising a filter surface with first and second sides. Means for providing a higher gas pressure on the first sides of the filter surfaces with respect to the second sides. A first conduit for withdrawing filtrate from the second side of at least one of the surfaces. A second conduit for withdrawing suspension liquid from adjacent the bottom of the elements. And, means for introducing suspension into said first sides of the surfaces to flow in a falling film down the first sides.
The apparatus may also comprise a sludge vessel connected to the second conduit external of the housing, and an open dregs vessel distinct from the sludge vessel connected to a bottom portion of the housing. Recirculating means are typically provided for recirculating suspension from the sludge vessel to the introducing means, and the introducing means may comprise a tray with perforated bottom mounted above the filter element. The introducing means may also or alternatively comprise at least one nozzle for directing suspension onto at least one of the filter surface first sides. When the housing is gas-tight gas pressure providing means comprise means for introducing gas under pressure into the housing. The gas pressure providing means may alternatively or additionally comprise means for applying a partial vacuum to the filter surface second sides. There may also be means for withdrawing gas from the second sides of the filter surfaces distinct from the first conduit, or for simultaneously withdrawing gas and filtrate through the first conduit.

Clarification of green liquor by falling film cross-flow filtration


A system and method are described for creation of a mosaic display system. A device is assigned an address which may be used to produce unique sequence of illumination which is based on a code determined by the address. A sequence of images of a number of devices may be used to determine a spatial location associated with a device address.

1. Field of the Invention
The present invention is related to lighting systems and information display by a group of devices.
2. Description of the Related Art
In many instances, it is desirable that a large display can be created from an array of independent elements. Some examples include display lighting and lighting for entertainment stages. Large displays are typically limited by the size of panels which can be fabricated such as LCD panels or LED sign boards. Such systems have advantages, but may be limited for various reasons.
In entertainment venues and artistic applications, there is the disadvantage that the cost of such displays may be high, but the usage may be comparatively low. Further there is no known way in which lighting can be placed in the areas of a stadium in which fans are located without blocking the view.
Due to these and other problems a method and system for a self-addressed information display would be greatly appreciated.

Method and system for self addressed information display


A method and an apparatus for cutting a laminate made of a brittle material and a plastic with a cutting tool is described. The plastic is heated up, thereby lowering its viscosity, at least in the region of a predetermined cutting line. A cutting tool is placed onto the plastic side of the laminate, the loading pressure being adjustable. By moving cutting tool relative to the laminate along the predetermined cutting line, the plastic is severed; at the same time the brittle material is scored, thereby inducing a mechanical stress. If appropriate, the mechanical stress along the cutting line is subsequently increased to exceed the rupture strength of the scored brittle material. A preferred application is the cutting of thin glass or glass-ceramic/plastic laminates.

1. Field of the Invention
The invention relates to a method and an apparatus for cutting a laminate made of a brittle material and a plastic with a cutting tool. The cutting of thin glass or glass-ceramic/plastic laminates is a preferred application.
2. Prior Art
Laminates made of a brittle material and a plastic are composite workpieces, the component parts of which consist of materials that differ greatly on account of their mechanical and thermal properties.
Plastics customarily used for the production of these laminates are generally mechanically relatively flexible or ductile and have a high thermal expansion of typically 20 to 80 ppm/K and a low softening temperature of typically 120 to 260xc2x0 C.
In contrast to this, brittle materials, such as glass, glass-ceramic or ceramic material, used for the production of the above-mentioned laminates are mechanically brittle and generally have a low thermal expansion and a high softening temperature. The thermal expansion of glass is typically around 3.5 to 11 ppm/K and the softening temperature TG is typically 500 to 750xc2x0 C .
Because of the stated very different physical properties of the two materials, until now no method or apparatus has existed for cutting a laminate comprising a brittle workpiece and a plastic with a cutting tool in one operation. The previously known methods and apparatuses relate only to the cutting of the respectively unprocessed material, but not of the composite.
To mechanically cut an unprocessed brittle material, such as glass for example, the glass surface is scored, for example by means of a diamond cutter or a small cutting wheel or a cutting blade made of hard metal. The surface damage produced in this way then represents a rupture joint of the glass, along which the crack runs in a controlled manner under tensile loading. During scoring of the glass, the normal force exerted on the cutting instrument must not exceed a certain value, dependent on the thickness of the glass. Otherwise, this generally leads to an uncontrolled rupture of the glass (H. Jebsen-Marwedel and R.Brxc3xcckner (editors), Glastechnische Fabrikationsfehler [glass manufacturing defects], Springer-Verlag, Berlin, Heidelberg, N.Y., 1980, page 577 et seq., Chapter 12.7, F. Kerkhof and B. Ganswein, Das xe2x80x9cSchneidenxe2x80x9d des Glases [the xe2x80x9ccuttingxe2x80x9d of glass]).
In addition to conventional mechanical cutting, methods in which the inducement of stresses along the cutting line is produced by thermal means have been known for some time. For example, DE 197 15 537 A1 discloses a method and an apparatus for severing flat workpieces made of brittle material, in which a laser beam is used to induce a thermomechanical stress along a separating line.
Furthermore, cutting the unprocessed brittle.material by means of sand blasting using a mask (JP 06008145 A) or by means of water-jet cutting using an abrasive agent (DE 35 33 340 A1) are known.
In contrast to this, unprocessed plastic films are generally either cut with a shear-action cut, using a shearing action of two sharp-edged hard-metal blades moved against one another, or by using a very sharp cutting knife or cutting wheel.
However, all the methods mentioned above are unsuitable for cutting a laminate of the type mentioned, for example a glass/plastic laminate. It is directly evident that the shear-action cutting of the laminate is possible only when using thin types of glass. However, here too the shear-action cut produced by the shearing action in the thin glass sheet gives rise to uncontrolled brittle cracks transversely to the cutting direction. Although a sharp, scalpel-like cutting knife is capable of severing the plastic film, it is not able to cut through or score the glass. Rather, it would very quickly be blunted on the glass surface.
When cutting with a diamond or a small hard-metal wheel, it is necessary according to the above to keep the loading pressure below a certain limit value to avoid uncontrolled rupture of the glass. The maximum loading pressure of the cutting tool limited in this way is not sufficient, however, to sever the film of the laminate composite reliably. On account of its flexibility, relatively high loading pressures (or normal forces) would be required for severing the plastic film, but for their part would again lead to uncontrolled rupture of the glass.
Because of the foregoing facts, it is not possible with the conventional mechanical cutting methods to cut these laminates in one operation. Alternative methods for cutting these composite pieces have a series of disadvantages.
In the known laser cutting, the apparatus expenditure is significantly greater, on account of the laser and the necessary optical peripherals, resulting in significantly higher costs. Vaporized or even pyrolyzed material may be deposited on the laminate or the optical components.
Water-jet cutting leads to soiling of the surface and to surface defects due to the water and the admixed abrasive agent. Cutting by means of sand blasting likewise leads to soiling of the surface and to surface defects of the laminate. These methods usually entail additional cleaning expenditure.
The introduction of these laminates, such as thin glass/plastic laminates for example, into existing product applications, for example in the display industry as a substitute for thin glass substrates, is facilitated considerably if there is an available cutting method which is as compatible as possible with the conventional cutting techniques, causes low additional costs and, if appropriate, can be implemented in existing glass cutting installations.
An object of the present invention is to provide a method and an apparatus for cutting a laminate made of a brittle material, in particular made of glass, glass-ceramic or ceramic material, and a plastic with a cutting tool, whereby the laminate is to be cut as far as possible in one operation, and at the same time a high cutting accuracy and faithfulness to contours as well as rapid cutting are to be made possible.
It is another object of the invention to design the method and the apparatus in such a way that they are compatible with existing cutting methods, that only low additional costs result and that they can, if appropriate, be implemented in existing cutting installations.
According to the invention, these objects are achieved by a method comprising the steps of:
heating the plastic at least in the vicinity of a predetermined cutting line, thereby lowering the viscosity of the plastic,
placing or engaging a cutting tool onto the plastic side of the laminate and adjusting the loading pressure of the cutting tool on the surface of the laminate,
moving the cutting tool relative to the laminate along the cutting line, with severing of the plastic and simultaneous scoring of the brittle material, thereby inducing a mechanical stress, and
additionally increasing, if appropriate, the mechanical stress along the cutting line to exceed the rupture strength of the scored brittle material.
According to the invention, these objects are also achieved by an apparatus comprising
means for heating the plastic at least in the vicinity of a predetermined cutting line, thereby lowering the viscosity of the plastic,
a cutting tool engageable with the plastic side of the laminate with an adjustable loading pressure of the cutting tool on the surface of the laminate,
means for producing a relative movement between cutting tool and laminate along the cutting line, for the purpose of severing the plastic and simultaneously scoring the brittle material, thereby inducing a mechanical stress, and
means for additionally increasing the mechanical stress along the cutting line to beyond the rupture strength of the scored brittle material, if appropriate.
The measures according to the invention make it advantageously possible to cut a laminate made of a brittle material and a plastic, in particular a laminate made of a brittle material laminated on one side with plastic, with a single cutting tool in one operation.
This is advantageous since the use of two cutting tools guided towards each other or one after the other always necessitates complicated and process-sensitive adjustment work, which is not needed in the case of the present solution.
The cutting tool must be guided on the plastic side of the laminate in order to sever the plastic reliably, and at the same time be able to score the brittle material for a brittle fracture at the cutting point.
To solve the fundamental problems mentioned at the beginning in the mechanical cutting of these laminates, it is necessary to lower the high loading pressure of the cutting tool for severing the plastic. By heating-up the plastic at least in the region of a predetermined cutting line, its viscosity is considerably lowered, and a small loading pressure of the cutting tool is already sufficient to sever the plastic.
The possibly required additional increase in the mechanical stress along the cutting line up to the rupture strength of the scored brittle material can be carried out, for example, by bending in the region of the score, a stress-induced crack propagation taking place along the cutting line.
To cut a laminate made of a brittle material laminated on both sides with plastic, the plastic on each side of the laminate is severed and the brittle material is scored either on one side or on two sides.
The severing of the plastic and the scoring of the brittle material may in this case be performed in a single method step with two oppositely arranged cutting tools or in two successive method steps with at least one cutting tool. For this purpose, the plastic is heated up at least in the region of the predetermined cutting line, thereby lowering the viscosity of the plastic, the heating-up taking place at least on the plastic side of the laminate on which the cutting tool is being placed at the time. The cutting tool is placed on one plastic side of the laminate, the loading pressure of the cutting tool on the surface of the laminate being adjustable. A relative movement between cutting tool and laminate is produced along the cutting line, with severing of the plastic on this side.
On the opposite plastic side of the laminate, the cutting tool or a further, additional cutting tool is placed, the loading pressure of the cutting tool on the surface of the laminate being adjustable. A relative movement between cutting tool and laminate is produced along the cutting line, with severing of the plastic and simultaneous scoring of the brittle material, thereby inducing a mechanical stress. If appropriate, the mechanical stress along the cutting line is additionally increased to beyond the rupture strength of the scored brittle material.
The cutting of the laminate made of a brittle material laminated on both sides with plastic, in which the severing of the plastic and the scoring of the brittle material is performed with two oppositely arranged cutting tools. The method according to the invention for cutting this laminate preferably includes the following method steps:
heating-up the plastic at least in the region of the predetermined cutting line, thereby lowering the viscosity of the plastic,
placing a respective cutting tool onto each plastic side of the laminate, the loading pressure of the respective cutting tool on the surface of the laminate being adjustable,
producing a relative movement between the cutting is tools and the laminate along the cutting line, with severing of the plastic and simultaneous scoring of the brittle material, thereby inducing a mechanical stress, the brittle material being scored on one side or on both sides, and
additionally increasing the mechanical stress along the cutting line to beyond the rupture strength of the scored brittle material if appropriate.
In this case, the two cutting tools are preferably arranged directly oppositely and execute a synchronized movement in relation to the laminate along the cutting line.
If the two cutting tools are arranged with a lead with respect to one another, the cutting tool which severs only the plastic on one side of the laminate is preferably arranged leading the opposite cutting tool, which severs the plastic and at the same time scores the brittle material.
The plastic is preferably heated up by radiation, in particular infrared and/or laser radiation and/or by a hot-gas jet. In this case, it is also possible for the entire laminate to be heated up.
The heating-up of the plastic may also be performed, however, by the heated cutting tool, in particular by its heated lower end. In this case, the heating-up of the plastic can be performed both by means of heat energy transfer alone, through the hot cutting tool, at least in the region of the cutting line, and also in addition to the heating-up mentioned.
The heating-up of the plastic may be performed both beyond its softening temperature and below its softening temperature, preferably just below its softening temperature.
By producing a relative movement between cutting tool and laminate, thereby moving the cutting tool and/or moving the laminate along the predetermined cutting line, the heated-up plastic is severed.
Furthermore, the surface of the brittle material can be scored by the cutting tool, and a rupture joint produced, in the same operation. Since the plastic side of the composite has then already been severed, the separating of the laminatexe2x80x94by a tensile stress-induced crack propagation along the rupture joint of the brittle materialxe2x80x94is ensured. The cutting speeds which can be achieved in this case for the cutting-through of the plastic and the simultaneous scoring of the brittle material are comparable with those of conventional glass cutting.
The melted plastic film at the cutting point additionally makes it possible to dispense with the wet film, of water, glycol or propanol for example, often used in conventional glass cutting for improving the cutting quality and for increasing the edge life of the cutting tool.
A fine cut, suitable for severing the plastic and at the same time scoring the brittle material, is preferably obtained by cutting the laminate with a cutting tool having a mounted diamond tip, with a cutting wheel or with a cutting blade.
Diamond, as the hardest mineral, is ideally suited for cutting the laminate, on account of this outstanding property, mounted in the cutting tool, irrespective of whether the natural or artificially cut edges take effect.
Cutting wheels and/or cutting blades that consist of a particularly hard and tough alloy or of a ceramic, in particular of a tungsten-carbide and/or diamond-containing sintered metal, are preferably used. The cutting wheels are preferably tapered in a wedge-shaped manner and provided on the outer edge with highly polished facets.
By inducing vibration, the cutting tool, and particularly its lower end, can be made to undergo axial and possibly also transverse vibrations of low amplitude and adjustable frequency. The cutting is improved as a result. An improvement in the cutting action is not dependent on a particular frequency. However, it has been found that higher frequencies have a better effect as a result of the higher number of vibrations per unit of time. The application of ultrasound is preferred, the high frequency of which can be generated by relatively inexpensive means. Frequencies in the range above 100 kHz can be generated with the required amplitudes only with relatively great expenditure. For producing the ultrasound, a modulator is preferably used, for example an oscillator crystal, or a magnetostrictive modulator, for example a nickel rod introduced into a strong magnetic alternating field. The ultrasound produced by ultrasonic stimulation is understood to mean sound waves at frequencies higher than 16 kHz. According to the invention, sound waves at a frequency of from 20 kHz to 100 kHz and an amplitude of from 5 xcexcm to 40 xcexcm are preferably used. In this case, vibrations of the cutting tool executed longitudinally and/or transversely with respect to the cutting direction bring about a better material displacement of the plastic away from the rupture joint. In this way, renewed flowing together of the just severed, still soft plastic is prevented. The axial vibrations of the cutting tool lower the thrust and bearing forces required for cutting through the plastic and at the same time scoring the brittle material.
The measures according to the invention enhance the cutting quality and reduce the risk of an uncontrolled brittle fracture of the brittle material. As a result, they assist the performance of the process and improve the achievable yield in the cutting operation or make the operation possible in the first place.
The method and the apparatus are suitable with preference for cutting laminates, in particular thin laminates, made of a brittle material, for example of a glass, glass-ceramic or ceramic sheet, and of a plastic, in particular of a plastic film, it being possible for the plastic film to be a scratch-protective film, preferably a scratch-protective film of polyethylene, or of a sprayed-on polymer film.
In principle, the method and the apparatus are suitable for cutting laminates made of a brittle material and a plastic, the viscosity of which can be lowered by means of heating-up by the cutting tool. Suitable plastics are, for example, thermoplastics, and those particularly suited are, for example, polyamides, polycarbonates, polyether sulfones, olefin copolymers, polyethylene-naphthalenes, polyarylates, polypentadienes or polyethylene terephthalate (PET).
The laminates preferably have in this case a thickness of the plastic of from 1 xcexcm to 300 xcexcm and of the brittle material of from 10 xcexcm to 300 xcexcm.
The brittle material and the plastic are preferably bonded to one another by means of a layer of adhesive, the layer of adhesive preferably having a is thickness of from 2 xcexcm to 50 xcexcm.
Alternatively, the plastic may be applied to the brittle material by extrusion, by a casting, spraying or roller-coating method or by laminating on a plastic film.
The method and the apparatus are also suitable, however, for cutting laminates made of a relatively thick brittle material, for example of glass, in particular flat glass, glass-ceramic or ceramic material, and of a plastic, the thickness of the brittle material preferably being up to 30 mm.
Furthermore, laminates of the type mentioned in which the brittle material consists for example of silicon, germanium or carbon can also be cut.
The production of a satisfactory cut line and, in particular, of a satisfactory score path requires a particular arrangement of the cutting tool. The angle between the longitudinal axis of the cutting tool and the cutting plane in the cutting direction is preferably adjustable in the range from 55xc2x0 to 75xc2x0. It is particularly preferred for the angle to be 65xc2x0.

Method and apparatus for cutting a laminate made of a brittle material and a plastic


A high adhesion uniform forsterite insulating film can be formed on the surface of a grain-oriented silicon steel sheet by the application of an annealing separator consisting mainly of magnesia having a narrow activity distribution defined by the citric acid activity of the magnesia which varies depending upon the variation of final reaction ratio of the magnesia as determined by the method for measuring the citric acid activity of magnesia, where the final reaction ratio of the magnesia is the ratio of that amount of the magnesia which finally reacts with citric acid to the total amount of magnesia mixed with the citric acid.

1. Field of the Invention
The present invention relates to a method of forming a forsterite insulating film on the surface of a grain-oriented silicon steel sheet.
2. Description of the Prior Art
As a method of forming an insulating film on the surface of a grain-oriented silicon steel sheet, there has generally known a method, wherein a silicon steel sheet is cold rolled into a given final gauge, the cold rolled steel sheet is decarburized at a temperature of 700.degree.-900.degree. C. under a wet hydrogen atmosphere, to form a sub-scale containing silica on the surface of the steel sheet, an annealing separator consisting mainly of magnesia is applied to the steel sheet surface, and the above treated steel sheet is wound up in the form of a coil and then subjected to a final annealing to form a forsterite insulating film on the surface of the silicon steel sheet.
The forsterite insulating film formed in the above described method has a high influence upon the appearance of the final product. When the film is ununiform, the product cannot be supplied to the market, and therefore the film has a high influence upon the production yield of the product. Particularly, magnesia used as a main component of the annealing separator has a very high influence upon the property of an insulating film, which will be formed during the final annealing, and therefore a large number of investigations have hitherto been carried out.
For example, Japanese Patent Application Publication No. 3,726/66 takes a notice of the particle size of primary particle of magnesia to be used as an annealing separator, and discloses a method, wherein a slurry of magnesia having a particle size of the primary particle of 170-280 A is applied to the surface of a silicon steel sheet, and a substantially pure magnesium oxide film tightly adhered to the steel sheet surface is formed. Further, Japanese Patent Application Publication No. 14,162/70 discloses a method, which uses magnesia obtained by firing magnesium hydroxide containing not larger than 0.2% of impurity in two stages of low temperature and high temperature, and containing at least 70% of particles having a particle size of not larger than 3.mu..
In addition to the above described methods, various proposals have been made with respect to annealing separator. Some of the proposed annealing separators are effective, but they are expensive in the commercial scale mass production. Moreover, since there are various factors having an influence upon the property of annealing separator, the obtained result often lacks reproducibility, and it has been impossible to prevent completely the formation of film, which cannot be used for practical use.

Method of forming a forsterite insulating film on the surface of a grain-oriented silicon steel sheet


An automated order picking system assembled from known, available components and that includes a manager computer to receive orders for goods from a customer and to break the order down into requested full pallets of multiple ordered layers of goods; layers of goods ordered by the customer; compatible ordered layers of goods that can be combined into full pallets; and compatible cases of ordered goods that can be formed into layers and into full pallets of multiple layers of goods; and vertical cells for receiving, storing and delivering cases of the goods. The vertical cells comprise towers having mutually facing tower sections that receive goods delivered to feed conveyors by gantry robots having end effectors capable of handling the goods and the tower sections passing the goods back and forth as the goods are moved downwardly for placement on the discharge conveyor under the control of a programmable logic computer. The full pallets, full layers and cases of goods are conveyed to a palletizer to be organized into the requested orders.

1. Field
This invention relates to automated material handling systems. It is particularly directed to mechanized systems for receiving, storing, and delivering goods quickly and in a desired selected order.
2. State of the Art
There are widespread needs for material handling systems capable of receiving, storing and delivering goods in a selected order. Many such systems, often referred to as "order picking systems," have been developed. Such systems constitute means for reducing manual handling of goods; improving the accuracy of goods handling; increasing the volume of goods that can be handled; and reducing the number of injuries to workers.
Order picking systems are applied to a wide variety of circumstances and environments. In general, they may be regarded as involving the retrieval ("picking") of designated goods from various designated storage locations ("addresses") from which they are delivered to a remote accumulation center. Upon accumulation, the goods are sorted into individual lots or orders. A typical objective of an order picking system is to retrieve individual case lots of designated goods from diverse locations within a warehouse and to assemble (palletize) the retrieved cases into ranks and files in a plurality of layers stacked on a pallet. While many of the operations required for such systems have been mechanized, the delivery and organization of cases of different goods or styles of goods to the final assembly or palletizing stage of the delivered cases has generally involved considerable manual labor.
Material handling systems developed in the past have combined known devices, such as conveyer belts, empty pallet feeders, depalletizers, unscramblers, wrappers and similar apparatus. These systems have typically adopted a horizontal flow, rack/conveyor approach that has proven to be costly, complex, unreliable and difficult to maintain. These known systems are also generally incapable of meeting changing needs. Once installed, they have been unduly limited as to the amount of material that can be processed and the speed with which product can be delivered from storage to a pick-up location.
U.S. Pat. No. 4,621,745 to Grace discloses a mechanized carton picker configured as a vertically accumulating and dispensing apparatus for containers. Cartons, cases or other suitable containers are loaded by a feed conveyor discharging onto a supply conveyor that feeds the top of a tower. The containers are dispensed seriatim, as needed, from the bottom of the tower, e.g., onto a moving discharge conveyor belt. The vertical tower thus provides a vertical queue or stack of containers of a product in storage. The individual containers progress via tilting shelves from the top to the bottom of the queue as containers lower in the queue are dispensed. Additional containers are loaded at the top of the tower as required to maintain inventory.
The use of vertical storage systems has been well known as a means of achieving maximum use of storage space. For years, it has been common to use operator controlled fork lifts and cherry pickers to travel between banks of high rise storage shelves. An individual operating such equipment can place items on the storage shelves for storage and subsequently remove the items from the shelves for delivery to a collection location. While providing for efficient use of available storage space, the use of high rise shelving and manual placement of goods for storage and removal of the goods on a selected basis for delivery is slow and labor intensive. In addition, further labor is often required to consolidate the selected goods for efficient delivery to a pick-up location.
It is not uncommon for workers to make mistakes while placing, retrieving or consolidating the goods, or for workers to be injured in the performance of their jobs.
More recently, various proposals have been made for storage and distribution systems utilizing computers to control flow of goods both into storage and out for delivery, while maintaining accurate data on the availability of goods and their locations.
It has also become widely accepted, particularly in the grocery business, as well as in other businesses such as, for example, those dealing with soft goods, automotive supplies, parts supplies and many other types of products, to deliver the goods to a pick-up location on pallets. The delivery location may be a truck, box car or other transport system or may merely be a storage location where the goods await further handling and transport.
The pallets for a particular industry are generally essentially standardized in size and loading. In the grocery industry, for example, the pallets are most often rectangular and are typically forty inches wide by forty-eight inches long by five inches thick. Standard pallets of this size will conveniently and efficiently fit into and fill trucks, box cars, sea containers, etc. The pallets are generally loaded with cases containing the goods and with the cases arranged in layers. Each layer is arranged to be able to support another layer or layers, and a typical such pallet may support as many as forty to eighty cases. The manner of loading each pallet depends on the type of cases delivered and whether different case types need to be placed on a pallet in correspondingly different patterns.
When it is determined that goods are to be delivered to a pick-up or staging location, it is possible that the order placed for such goods may be for full pallets of one type of goods or full pallets of a number of different types of goods. The order may require pallets having specific layers dedicated to cases of respective types of goods or the order may require pallets having layers of cases of mixed types of goods. The orders for goods may include some full pallets of goods of one type or another, some pallets with different goods making up individual layers and for other pallets with mixed cases of goods within layers on the pallets.
In the past, computers have been used to determine order requirements and even to control delivery of goods to a location for storage and release of the goods for transport to a pick-up location. There has not heretofore been available any system capable of monitoring and controlling storage goods, storage replenishment as the goods are delivered from storage and the versatile delivery of the goods by full pallet. By "versatile delivery" is meant by pallet loads which are selectively loaded either by the same type goods, individual layers of different specified goods or different type goods in cases that are mixed within layers.
The development in recent years of mechanized and computer controlled robots having capabilities for selecting, picking up, transporting, and releasing selected goods of various types and in different patterns greatly increases the possibilities for mechanical handling of goods.
C&D Robotics of Beaumont, Tex. currently manufactures and markets robot units that are used in industry. Typical of the robot units currently marketed are open gantry units having a cantilevered axis and closed gantry units having a totally enclosed motion. C&D Robotics currently produces standard robot units having total load capacities, i.e. product carried, plus end effector used, of 120 to 350 pounds. Non-standard, structurally modified robot units are available to handle heavier loads, even exceeding 1,000 pounds.
The standard end effectors available for use with the C&D robotic units fall into a few general categories, for example: "fork and clamps," where bottom forks support the goods, while a top clamp steadies the goods for handling; "vacuum," where suction is produced either venturi action created using compressed air or by an integral blower with cups or platens, as required; "variable pitch vacuum," using vacuum cups that adjust under program control to handle a wide range of products; "top clamp," wherein parallel clamps are used on two or four sides of the product; and "hybrid," which comprises combinations or extensions of the other types.
U.S. Pat. No. 4,621,745 discloses a mechanized carton picker wherein vertical storage and dispensing apparatus is provided for the handling of containers of goods. Goods are loaded at the top of a tower and are selectively discharged from the bottom. The tower has a frame that defines first and second tower sections each supporting a number of vertically spaced shelf trays to support the containers placed on the trays when the tower is loaded. Each tray is mounted for cantilevered pivotal movement about a horizontal axis and is operated so that when a container is dispensed from a bottom shelf tray of one tower section, each higher tray of the tower sections, beginning at the bottom and progressing upward, one at a time, pivots to transfer its container to the next lower, upwardly tilted tray of the other tower section. The process is repeated until each container has been transferred to the next lower tray. As a container is loaded at the top of the tower, the shelf trays are operated to pass the container downwardly in zigzag fashion from one tray on one tower section to another tray on the other tower section until the container reaches the highest unloaded tray. This mechanized carton picker provides a means for efficient use of available space for storage purposes and a means for selective delivery of goods stored in the unit and is therefore well suited for use in the automated order picking system of the present invention.
A gantry robot, together with a mechanized carton picker tower and discharge output comprises a cell, forming a principal component of the present automated order picking system.


A mechanical device for generating actuating movement has a housing defining a first bore and a second bore contiguous therewith. The housing also defines radial ports that allow an environment about the housing to communicate with the first bore. A first piston is slidably mounted in the first bore. A second piston is slidably mounted in the second bore and is positioned so that it is flush with the first bore. A spring, coupled to the first piston, is capable of an at-rest state in which the first piston seals off the radial ports while being spaced apart from the second piston. The spring is also capable of a compressed state in which the first piston is positioned such that the radial ports communicate with the first bore between the first and second pistons. When the spring is released from its compressed state and allowed to transition to its at-rest state, the first piston moves to seal off the radial port(s) and subsequently pressurize any fluid in the first bore between the first piston and the second piston. If the fluid is incompressible (e.g., water), the pressurized fluid drives the second piston along the second bore to create the actuating movement.

Ordnance such as grenades, bombs, mines and torpedoes typically have an actuator in the form of a fuze or detonator which permits initiation of a main charge only when certain conditions are met. For example, if the ordnance is only supposed to detonate underwater, the fuze is designed to prevent in-air detonation. Several such fuzes are known in the prior art.
U.S. Pat. Nos. 3,765,331 (the '331 patent) and 3,765,332 (the '332 patent) disclose water-armed air-safetied detonators in which a plurality of small explosives are aligned in a spaced-apart fashion in a fuze housing. The first of these small explosives is a delay charge which ignites when the ordnance is launched or released. The delay charge eventually burns and flashes down an adjacent housing bore to ignite a transfer charge. Detonation of the transfer charge releases energy that is either used to move a piston (the '331 patent) or is in the form of a shock wave (the '332 patent). This released energy is delivered to a chamber that is flooded with either air or water depending on the environment in which the fuze is immersed. Adjacent the flooded chamber is a firing pin/percussion primer (the '331 patent) or just a percussion primer (the '332 patent). If the flooded chamber is filled with air, the released energy in the form of a moving piston (the '331 patent) or shock wave (the '332 patent) will not transfer through to the next stage of the fuze. If, however, the fuze is submerged in water, the flooded chamber is filled with water and the released energy entering the flooded chamber is transferred therethrough to the next stage of the fuze.
Although being air-safed, these devices still have several disadvantages. The use of explosives as part of the fuze train can be inherently problematic. These problems range from the safety concerns related to the construction and storage of such devices to the fact that these fuzes are not reusable. In general, use of stored energy for arming and firing is considered bad design practice because the energy is available at all times during storage and transportation, and may therefore be released due to unforeseen causes or situations. Further, the use of explosives eliminates these devices from consideration as an all-purpose actuator that is water-armed and air-safed.
To overcome the problems inherent with the use of explosives, a mechanical underwater firing mechanism is disclosed in U.S. Pat. No. 2,660,952. Briefly, a spring-loaded plunger is mounted in a housing. The head of the plunger is formed with a recess. Fitted in the housing coaxial with the plunger is a plug having a central bored portion in which a firing pin is temporarily positioned intermediately therein by a shear pin. As a result, small chambers are defined in the central bored portion on either side of the firing pin. The central bored portion of the plug opposes the plunger's recess and is sized at its exterior to fit within the recess. When the spring-loaded plunger is cocked, the head of the plunger is spaced apart from the central bored portion of the plug to define a chamber within the housing. An opening in the side of the housing at the chamber allows the environment surrounding the housing (e.g., air or water) to fill the chamber.
When the spring-loaded plunger is released, the plunger recess envelops the central bored portion of the plug to compress any fluid trapped in the small chamber of the central bored portion between the firing pin and the head of the plunger. If the trapped fluid is air, the compression thereof will not develop forces sufficient to cause the firing pin's shear pin to fail. However, if the trapped fluid is water, the compression forces imparted by the plunger will be sufficient to cause failure of the firing pin's shear pin thereby allowing movement of the firing pin to impact a primer.
While eliminating the use of explosives in the firing mechanism, this device has other disadvantages. For example, the requirement that a small chamber be defined in the central bored portion opposing the head of the plunger raises the possibility that an air bubble will form therein when the device is submerged in water. The presence of such an air bubble could prevent the mechanism from functioning underwater. At the same time, the requirement that the small chamber be present in the central bored portion could also bring about an unwanted firing. This could occur if the mechanism were not cocked and inadvertently dropped in water. Water could seep into the mechanism and fill the small chamber. Then, an in-air release of the (cocked) plunger could bring about movement of the firing pin just as if the mechanism were submerged in water. This is because surface tension in the small chamber could cause enough water to be retained therein to bring about this undesirable situation. Another disadvantage brought about by the requirement of the small chamber arises in sub-freezing environments. Specifically, water in the small chamber could quickly freeze due to its small volume. If this occurs, the mechanism will not function.

The United States of America as represented by the Secretary of the Navy


A solar powered light comprises a cover containing a fresnel lens structure (also referred to as a fresnel lens cover) which is disposed directly above and adjacent to a photovoltaic cell thereof. The fresnel lens cover comprises a continuous and smooth outer surface and a prismatic inner surface having a plurality of prismatic means arranged in concentric circles to bend incoming radiation, especially at high angles of incidence, such as during winter months or at the beginning or end of a day, toward an optical axis thereof. The prisms have different thicknesses and are arranged in different angular configurations to accomplish the desired bending at each point of the cover. In a preferred embodiment, additional prismatic means are formed on a peripheral portion of the outer surface to cover a photodetector used for sensing the absence of light and triggering circuitry to turn on the solar powered lights.

Electrically powered outdoor lighting systems are used to illuminate pathways, yards, parks and other like outdoor areas for security purposes. Commonly, such lights are connected to public utility systems or similar sources of electrical power, and are controlled by preset timing devices to illuminate desired areas at nightfall and automatically turn off at a predetermined time, for example, prior to daybreak.
Many conventional lighting devices require extensive cabling, suitable timing mechanisms and the like, and are thus relatively expensive to install and maintain. In addition, such lighting devices utilize electric power generated in a conventional manner such as by burning fuel. Burning fuel contributes to contamination of the environment and depletion of existing fuel resources.
More recently, self-contained solar powered illumination devices which utilize photovoltaic devices to charge batteries which, in turn, activate a light source contained therein, in the absence of sunlight, have been used for illumination and/or decorative purposes. Such self-contained devices are desirable because they are relatively inexpensive and require hardly any maintenance.
A plurality of such lights can be disposed in any predetermined arrangement, as desired, by pressing the light into the earth to position the lamp at a desired delineation or demarkation position. By thus positioning a plurality of the lights, a particular area, such as a pathway, may be easily delineated so that a person, even in complete darkness, may be able to follow the pathway without the necessity of producing sufficient light to illuminate the pathway.
Typically, solar powered lights include self-contained electrical storage devices, such as a battery which is maintained in a charged condition by a photovoltaic or solar cell array. Photovoltaic cells convert sunlight into electricity. A power supply electrical circuit controls the flow of current to a bulb contained within the solar powered light. The electrical power from the battery is supplied to the light bulb when the solar cell array is not producing electricity, that is, when the ambient light falls below a predetermined level and there is insufficient sunlight.
Although such solar powered illumination devices have been known to serve their purpose, they have not proven to be entirely satisfactory. During winter months, the run time of such solar powered lamps is about 30-35% of the run time obtained during the summer months because a large proportion of the sun's rays is reflected at the higher angles of incidence encountered during the winter. The same occurs at the beginning and end of a day, when the light levels are low and the angles of incidence are high.
Moreover, in present solar light constructions, the photovoltaic cells have substantially rectangular or square configurations. Thus, in circular solar lights there are substantial dead areas, such as at the four quadrants. Light impinging on these dead areas is not absorbed by the photovoltaic cell. Such lost radiation reduces the potential of current development by the solar powered light, which in turn affects the run time of the light.
In the past, because solar cells are expensive to produce, prior techniques have improved the efficiency of photovoltaic solar energy systems by attempting to focus incident sunlight from a large area onto smaller solar cells using a solar collector which incorporates optical concentrators. One such concentrator is a linear Fresnel lens. Because operation of such devices increases the radiant energy flux on the solar cells, the electrical current produced increases substantially. To efficiently carry this higher current, more and larger conducting elements are required. Such conducting elements are generally formed on the top of the solar cell itself, which prevents some of the sunlight from reaching the semiconductor material which converts the sunlight into electricity.
It is known in the prior art to provide covers for solar cells which refract incident sunlight away from conducting elements and concentrate it onto active cell areas. U.S. Pat. No. 4,711,972 to O'Neill discloses a solar cell cover geometry to improve the efficiency of solar cells used in a solar cell collector. The cover comprises a plurality of refractive prisms formed on the surface of the material, such prisms configured to refract incident sunlight onto small active cell areas rather than partially onto non-active conducting elements. Furthermore, the cover is configured such that a portion of the sunlight reflected from the cover itself is admitted into the cover and thereafter impinges upon the small active cell areas. The cover assembly of the O'Neill patent is also highly directional, requiring careful orientation and tracking relative to the sun.
Thus, a need exists for a means of effectively absorbing available radiation and increasing the run time of solar powered lights all year around and especially during winter months or at low ambient light levels.

Solar powered lamp having a cover containing a fresnel lens structure


Method of facilitating online interactions between voice talent users and second users. Voice talent users upload sample audio files containing voice recordings, and second users can do keyword searches for voice talent users or post jobs that can be searched by voice talent users. A second user sends a partial script to a voice talent user, who makes a voice recording of the partial script and uploads the same. The second user has the option to send a complete script to that voice talent user, and if so, the voice talent users makes a voice recording of the complete script and uploads the same as a final audio file. Upon acceptance of the final audio file and satisfaction of optional milestones established by the second user, a server remote from both users facilitates an electronic transaction between them using the server as an agent for the transaction.

The present invention relates to online management systems. More specifically, the present invention relates to an online system for facilitating and managing transactions between voice talent and employers who wish to temporarily avail of the services of the voice talent.
The field of voice over recordings, voice acting, and voice recordings for use in automated answering systems and the like is one that is ideally suited for today's computerized world. Not only is the need for such services increasing but, due to the nature of the service, the voice talent (those who provide the voices for the recordings) do not even have to be in the same physical locality as their clients.
In this field, voice talent, the people who provide the voices for everything from answering machines to radio/Internet commercials to corporate video advertising material, are contracted on a per job or per contract basis. As an example, a voice talent may take on a contract to record all the names of the people in an organization for use in their voicemail system. The voice talent would be paid a flat fee for recording all the names and, depending on the conditions of the contract, the payment may be staggered based on milestones such as completing predetermined percentages of the job. Similarly, a voice talent may be contracted to record a predetermined script which an organization may use for its advertising material such as a video or a radio commercial.
However, while this field is suitable for having the voice talent in one location and having the client at another location, there is currently no systems that allow this paradigm to be used with the Internet. Not only would such a system allow for a broader base of voice talents but it would also speed up the process as voice talent can receive contracts faster and get paid quicker. As well, such a system would help potential employers to find the right talent for the right job and, because of the increased competition between the voice talent, pay a fair price for the job.
There is therefore a need for a system which incorporates current Internet based technologies with the needs of the voice industry.

Computer-implemented method of facilitating online interactions involving voice recordings using multiple electronic interfaces


The invention provides a method of manufacturing a laminated ceramic capacitor, which method includes a step of forming an electrically conductive paste layer on a green sheet composed of lead system composite perovskite oxide. The paste includes a solvent in which are distributed metal powder including at least silver powder, organic titanium compound, organic rhodium compound and organic binder. An amount of titanium in the paste preferably is in the range of 0.02% to 0.09% by weight on the basis of a weight of the metal powder, and an amount of rhodium in the paste preferably is in the range of 0.10% to 0.60% by weight on the basis of a weight of the metal powder.

1. Field of the Invention
The invention relates to a method of manufacturing a laminated ceramic capacitor, and more particularly to a method of manufacturing such a capacitor using an electrically conductive paste used for the formation of an internal electrode of a laminated ceramic capacitor which uses lead system composite perovskite oxide as a dielectric substance.
2. Description of the Related Art
The laminated ceramic capacitor as aforementioned is manufactured generally in the following steps. First, lead system composite perovskite oxide powder as a ceramic dielectric substance powder is mixed with an organic binder and a solvent, and then the mixture is formed into a sheet by means of a casting process. Then, on the green sheet are formed electrically conductive paste layers which are to work as internal electrodes, by means of a screen printing process. After a certain number of the layers have been deposited, they are compressed to bond with each other. Then, the thus laminated layers is cut into individual capacitors. Then, the individual capacitors are fired so that a ceramic dielectric substance and metal powder in the paste are simultaneously sintered. Finally, an external electrode is formed.
In the above-described process, a step of simultaneously firing the dielectric ceramic in the form of a sheet and the metal powder in the electrically conductive paste to be sintered is indispensable to a method of manufacturing a laminated ceramic capacitor.
A laminated ceramic capacitor can have desired properties by forming ceramic dielectrics and internal electrodes closely integral with each other by means of the above mentioned firing step. Accordingly, it is quite important, in the firing step to avoid so-called "delamination of layers", which means a phenomenon wherein a ceramic dielectric is peeled off from an internal electrode in a laminated structure after the firing step, in order to obtain a capacitor having stable and reliable. The delamination of layers occurs when a stress acting on an interface of the metal (internal electrode) and the ceramic (dielectric substance) is greater than a bonding strength between them. In view of this point, the following are considered to be problems frequency found in a firing step.
1. A ceramic can have only a weak bonding strength with a metal, and hence it is impossible to strongly bond a ceramic to a metal.
2. Since there is a difference in a volume shrinkage due to firing between a ceramic and a metal, a stress would be generated at an interface of them particularly when the temperature is being raised in a firing step.
3. Because of a great difference in a thermal expansion coefficient between a ceramic and a metal, a volume expansion and shrinkage due to an increase or decrease in temperature during firing would entail a large stress.
Thus, in order to avoid delamination of layers between internal electrodes and dielectric substances in a laminated ceramic capacitor, an electrically conductive paste used for an internal electrode is required to have a great bonding strength with a ceramic dielectric and to generate a small stress.
A conventional electrically conductive paste used for a laminated ceramic capacitor is a mixture of metal powder including at least silver powder such as a mixture of silver powder and palladium powder, and a vehicle comprising an organic binder and a solvent. The mixture is well mixed by means of three rolls, and then used as the paste.
As aforementioned, in a conventional method of manufacturing a laminated ceramic capacitor, an electrically conductive paste including the mixture of metal powder including silver powder and a vehicle comprising an organic binder and a solvent has been used for formation of internal electrodes. However, an electrically conductive paste is required to have a characteristic by which a greater bonding strength would be generated between an internal electrode and a ceramic dielectric substance, and also by which a smaller stress would occur at an interface between an internal electrode and a ceramic dielectric substance, in order to enhance the stability and reliability of revelation of the capacitor characteristic.
In view of such a demand, there has not been suggested an electrically conductive paste manufactured only for a laminated ceramic capacitor. However, it is possible to solve the problems of the weakness of a bonding strength and the largeness of a stress by using an electrically conductive paste modified for another objects.
For instance, Japanese Unexamined Patent Public Disclosure No. 63-115691 discloses an electrically conductive paste having an improved bonding strength with a non-oxide ceramic such as AIN. In this Disclosure, an organic titanium family adhesion promotion agent or a titanate coupling agent is added to a conventional active silver solder paste, and hydrolysis of the titanate coupling agent with water absorbed in a surface of a ceramic substrate is used to improve the bonding strength. Though the electrically conductive paste aims to strengthen a bonding strength between high thermally conductive ceramic veneers or between such a ceramic veneer and a metal, the electrically conductive paste can be used as an internal electrode to thereby obtain a greater bonding strength between an internal electrode and a ceramic dielectric substance than that obtained by a lo conventional electrically conductive paste.
Japanese Unexamined Patent Public Disclosure No. 63-283184 has suggested an electrically conductive paste including conductive compound containing silver powder and palladium powder as indispensable constituents, and rhodium powder and/or organic rhodium compound. These ingredients are distributed in vehicle. The object of the Disclosure is to provide a paste which is to be used for forming electrically conductive patterns on a fired veneer glass substrate or a fired glass ceramic substrate, and which shows a good wettability to solder and does not degrade adhesion between a conductive compound and a substrate. As later explained in detail, the paste suggested in the Disclosure contains rhodium, and hence, when the paste is used for forming internal electrodes of a laminated ceramic capacitor, a volume shrinkage thereof due to firing in a firing step is similar to that of a ceramic dielectric. As a result, it is expected to obtain an advantageous effect that it is possible to avoid an occurrence of a stress produced due to a difference in a volume shrinkage generated due to firing between internal electrodes and ceramic dielectrics.
However, even if either paste disclosed in the above mentioned two Disclosures is used, only one of the two factors, namely a bonding strength and a stress which cause a delamination of layers in a step of firing a laminated ceramic capacitor, can be improved, and hence it is impossible to sufficiently avoid a delamination of layers.
For instance, the electrically conductive paste disclosed in the first mentioned Disclosure can strengthen a bonding strength between ceramic dielectrics and internal electrodes, however, a stress may be larger than a bonding strength due to a difference in a volume shrinkage due to firing or a difference in a thermal expansion coefficient.
On the other hand, the electrically conductive paste disclosed in the second Disclosure can reduce a possibility of production of a stress due to a difference in a volume shrinkage due to firing. However, a bonding strength remains as it is, and hence if a stress produced due to a difference in a thermal expansion coefficient is larger than a bonding strength, there would occur a delamination of layers while a temperature is being lowered in a firing step, a local concentration of stress due to a dispersion in a bonding strength between an internal electrode and a ceramic dielectric, and a microcrack due to the local concentration of stress.
In addition, the electrically conductive paste disclosed in the first mentioned Disclosure has to be fired in a vacuum or an inert gas atmosphere. On the other hand, if lead system composite perovskite oxide used for a laminated ceramic capacitor to which the invention is directed is fired in a vacuum or in an inert gas atmosphere, the dielectric characteristic thereof is influenced by anoxia, and thereby a dielectric constant thereof is lowered. In conclusion, the electrically conductive paste disclosed in the first mentioned Disclosure is not practically applicable to the manufacturing of a laminated ceramic capacitor in which an electrically conductive paste and a ceramic dielectric have to be simultaneously fired.

Method of manufacturing laminated ceramic capacitor