The present invention relates to a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising plastic and/or carbon aerogels, and a process for the preparation of such molding materials.

The present invention relates to a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising plastic and/or carbon aerogels, and a process for the preparation of such molding materials.
Precision casting in ceramic shell molds is a standard casting technique for preparing precision moldings from a wide variety of alloys. The molds are usually prepared by the lost-wax process, i.e., a wax molding of the part to be cast is wetted with a silica sol, sand-coated in several steps, dried, and then the shell mold is baked wherein the wax is melted and drained or burned in an autoclave. With modern casting processes, it is possible to achieve conformal casting with high fidelity (J. Sprunk, W. Blank, W. Grossmann, E. Hauschild, H. Rieksmeier, H. G. Rosselnbruch; Feinguxcex2 fxc3xcr alle Industriebereiche, 2nd edition, Zentrale fxc3xcr Guxcex2verwendung, Dxc3xcsseldorf 1987; K. A. Krekeler, Feingiexcex2en, in: Handbuch der Fertigungstechnik Bd. 1, editor: G. Speer, Hanser Verlag, Mxc3xcnchen 1981).
Aerogels are highly porous open-cell oxidic solids which are usually obtained by sol-gel processes from metal alkoxides by polymerization, polycondensation to gels, followed by supercritical drying. For some years, it has also been possible to prepare plastic gels by a sol-gel process and to convert them to a highly porous organic solid by supercritical drying. Pyrolysis of such plastic aerogels under a protective gas or vacuum at temperatures above 1000xc2x0 C. converted them to carbon aerogels. Like the oxidic aerogels, plastic and carbon aerogels have extremely low effective thermal conductivities (on the order of some mW/K/m), but they are significantly lighter than the oxidic aerogels. The physical and mechanical properties of plastic and carbon aerogels are documented in the literature (R. W. Pekala, C. T. Alviso, F. M. Kong, S. S. Hulsey; J. Non-Cryst. Solids 145 (1992) 90; R. W. Pekala, C. T. Alviso, Mat. Res. Soc. Symp. Proc. 270 (1992) 3; R. Petricevic, G. Reichenauer, V. Bock, A. Emmerling, J. Fricke; J. Non-Cryst. Solids (1998)). They can be varied within a wide range by appropriately selecting the starting materials, their mixing ratio and the preparation process.
Therefore, it has been the object of the present invention to simplify the prior art processes for the preparation of molding materials for the precision casting and dead-mold casting of metals and metal alloys, especially to reduce the time required for drying in the process.
In a first embodiment, the above object is achieved by a molding material for the precision casting and dead-mold casting of metals or metal alloys comprising highly porous open-cell plastic and/or carbon aerogels, obtainable by the sol-gel polymerization of organic plastic materials, optionally followed by partial or complete pyrolysis of the plastic aerogel obtained.
The molding material according to the invention is particularly suitable for use in lost-wax processes, eliminating the need for application in multiple steps, as with oxidic gels of the prior art.
According to conventional techniques, the molds thus obtained are filled with a melt, and the melt is solidified. In the usual casting techniques, the heat is dissipated through the shell mold or the molding sand. In contrast, since carbon aerogels are quasi-adiabatic, casting and solidification in aerogels means that the heat is dissipated solely through feeders and risers or through especially provided cooling means; conveniently, but not necessarily, the feeders and risers themselves may be used for this purpose. Thus, a completely controlled solidification is possible, and the assembly can be adjusted in accordance with the range of properties required.
The aerogel molds prepared according to the invention are especially suitable for casting aluminum alloys (the casting mold having to be heated virtually not at all, since there is no heat dissipation through the mold itself). This increases economic efficiency because energy costs can be lowered. Magnesium and titanium alloys do not react with carbon either; thus, the carbon aerogel molds are also a good selection as molding materials for these alloys under protective gas or vacuum.
One particular advantage of the molding materials according to the invention is that the sol-gel formation can be completed within a few hours at room temperature, i.e., in particular, at temperatures below the pour point of the wax. Supercritical drying, as with the purely inorganic gels, is not necessary. Nevertheless, it is possible to adjust the cell size in the micrometer range. In addition, when drying is performed in a supercritical range of temperatures, cell sizes in the nanometer range are also possible.
In addition, the molding materials according to the invention may also contain inorganic or organic filler materials. This essentially means stable materials which are inert under solidification conditions. For example, inorganic filler materials may be selected from alumina, titania and/or quartz each of which may be employed in a proportion of from 5 to 30% by volume. Fillers according to the present invention further include fibers, allowing a fiber reinforcement by organic, inorganic, carbon and/or SiC fibers in appropriately the same proportion.
Similarly, it is also possible to employ organic fillers, for example, thermoplastic or thermosetting plastic particles, such as polystyrene, or organic (such as polyacrylonitrile), inorganic (such as SiC) or carbon fibers. However, it has to be taken care that these materials are also removed by melting or burning off in the pyrolysis of the plastic gels. Using such materials, it is possible, however, to control the shrinkage during the pyrolysis.
It is particularly preferred according to the present invention to employ for the molding material resorcinol/formaldehyde-based plastic aerogels which, when having an appropriate composition and an appropriate content of basic catalyst, can be converted to a microstructured plastic aerogel at temperatures of between 20 and 50xc2x0 C. without supercritical drying. By selecting the composition, the sol-gel polymerization can be adjusted in such a way, for example, that a highly viscous liquid is first formed which can be applied to a wax mold. This can also be done in several working cycles so that the layer thickness can be adapted to the requirements of the applications in casting.
Thus, another embodiment of the present invention is a process for the preparation of casting molds for the precision casting and dead-mold casting of metals or metal alloys using highly porous open-cell plastic and/or carbon aerogels, comprising the steps:
a) wetting a wax mold with a plastic sol of an appropriate composition containing an appropriate catalyst;
b) converting the sol to a gel at a temperature below the pour point of the wax;
bxe2x80x2) optionally, applying one or more additional layers of the sol each of which is partially or completely converted to the gel form;
c) drying the gel at a temperature below the pour point of the wax; and
d) melting and draining or burning off the wax from the solidified gel at a temperature above the pour point of the wax.
An alternative process for preparing the casting mold consists in:
a) placing a wax molding in a container;
b) filling the container partly or wholly with a plastic sol;
c) converting the sol to the gel form at a temperature below the pour point of the wax;
d) drying the gel at a temperature below the pour point of the wax; and
e) melting and draining or burning off the wax from the solidified gel at a temperature above the pour point of the wax.
Thus, it is possible simply to place the wax molding in a suitable container, fill it with the starting solution for the plastic aerogels and then perform the process for preparing the aerogel.
In this way, solid, but light-weight quasi-adiabatic molds can be prepared by analogy with the known block mold process (which essentially uses gypsum).
The conversion temperature of the solution to a plastic aerogel must be adapted to the melting point of the wax. After conversion to a plastic aerogel, the wax can be removed by melting, and at the same time, with the exclusion of air, the conversion to a carbon aerogel can be effected. Depending on the composition of the starting solution, the gelling temperature and the density of the porous body formed, casting molds can be prepared both as a plastic and as a carbon aerogel which have a smooth finish on a micrometer scale and provide conformal molding. According to the invention, the preparation of molds up to the stage of the plastic aerogel usually takes from 1 to 3 days, often only up to 24 hours. The duration of pyrolysis is determined by the thickness of the casting shell mold; for example, a wall thickness of 1 cm requires a time of less than 24 hours, often less than 10 hours. As compared to the preparation of typical precision casting shell molds using oxidic sol-gel processes, the preparation times are short and thus economically efficient. In both process steps, shrinkage is always isotropic and may vary between a few percent and 20%. It can be reduced and influenced by selecting the composition of the sol, the drying conditions, the mold material and fillers, and thus is under control.
By way of example, the respective process steps for the preparation of plastic aerogel molds are characterized as follows:
a) Block mold method:
1. Preparation of the starting solution (resorcinol, formaldehyde, water and basic catalyst);
2. storage of the wax model in a PTFE or glass container;
3. filling the container in 2. with the starting solution (as the specific gravity of the wax models is generally lower than that of the solution, the mold must be correspondingly weighted (best at the risers and feeders));
4. gelling in a temperature-controlled water bath (in this case, the mold should be tightly sealed lest the solution should change its composition) or in a forced air oven in a temperature range of from 20 to 50xc2x0 C.;
5. after the gelling is complete, the gel, while still wet, is dried at the same temperature in the closed mold to form the microstructured plastic aerogel;
6. placing the plastic aerogel block with the enclosed wax model in a pyrolysis oven which is sufficiently flushed with a protective gas. Heating to 1050xc2x0 C. over a period of about 3 hours and maintaining this temperature for about 4 to 24 hours. The mold is placed in such a way that the wax can drain out.
b) Precision casting shell molds:
1. Identical with a) 1.;
2. identical with step a) 4. Gelling may be stopped in order to keep a highly viscous liquid;
3. immersing the wax molding into the partly gelled starting solution; and
4. final gelling and drying in a forced air oven at about 40xc2x0 C.;
5. if steps 3. and 4. are repeated (without complete drying), layers of different thicknesses can be applied, followed by final drying and conversion to a plastic aerogel in the forced air oven;
6. identical with a) 6.

Precision casting and dead-mold casting in plastic/carbon aerogels

Abstract: The molding material comprises highly porous open-cell plastic and/or carbon aerogels, obtainable by the sol-gel polymerization of organic plastic materials, optionally followed by partial or complete pyrolysis of the plastic aerogel obtained.

DLR Deutsches Zentrum fur Luft-und Raumfahrt e.V.


A method for improving the service life of passive filtration and infiltration devices. Contaminated water, such as stormwater runoff or wastewater, is filtered through a media comprising of a mixture of filter media and stimuli-responsive polymer particles. The polymer particles reversibly expand/contract in response to changes in certain environmental stimuli, resulting in increased macropores and breakup of sediment and crust that would otherwise reduce hydraulic flow. The method is effective in a variety of passive devices, including conventional particulate filters, infiltration systems, and high loading canister, cartridge and catch basin filter devices.

1. Field of Invention
The present invention relates to clogging and means of reducing such in filters that are used for the removal of contaminants from liquids.
2. Prior Art
The 1972 Clean Water Act (CWA) has been the basis of increasing regulatory controls of both point and nonpoint source pollution. Direct discharges or "point source" discharges are from sources such as pipes and sewers. Nonpoint source (NPS) pollution, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources and is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and man-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and underground sources of drinking water. The objective of the CWA is to restore and maintain the chemical, physical, and biological integrity of the nation's waters by preventing point and nonpoint pollution sources, providing assistance to publicly owned treatment works for the improvement of wastewater treatment, and maintaining the integrity of wetlands. Pollutants regulated under the CWA include "priority" pollutants, including various toxic pollutants; "conventional" pollutants, such as biochemical oxygen demand (BOD), total suspended solids (TSS), fecal coliform, oil and grease, and pH; and "non-conventional" pollutants, including any pollutant not identified as either conventional or priority.
In 1987, the CWA was amended to require EPA to establish a program to address stormwater discharges. In response, EPA promulgated the Pollutant Discharge Elimination System (NPDES) stormwater permit application regulations (EPA, 2004). These regulations require that facilities with the following stormwater discharges apply for an NPDES permit: (1) a discharge associated with industrial activity; (2) a discharge from a large or medium municipal storm sewer system; or (3) a discharge which EPA or the state/tribe determines to contribute to a violation of a water quality standard or which is a significant contributor of pollutants to waters of the United States. As part of stormwater permits, facilities are often required to implement pollution prevention plans, which identify potential sources of pollution and describe and ensure the implementation of practices that reduce the pollutants in stormwater discharges. These practices are referred to as best management practices (BMPs). Through a variety of programs (including, as appropriate, non-regulatory or regulatory programs), states assist and encourage producers to use best management practices to reduce or prevent instances of nonpoint source pollutants migrating into waters.
Best management practices that provide treatment of contaminated stormwater and wastewater include those that utilize filtration or infiltration. Sand filters have proven effective in removing pollutants from stormwater runoff (EPA, 1999) and on-site wastewater treatment (EPA, 2002). A typical sand filter system consists of a pretreatment or sedimentation chamber, which removes heavier suspended solids that can clog the downstream filter, and a filtration chamber, which removes additional pollutants by filtering through a sand bed. The treated filtrate normally is then discharged through an underdrain system. Traditional stormwater sand or media filters are considered low loading rate treatment systems. For relatively higher loading rate applications, for example at sites where space is constrained, there are a number of proprietary "ultra-urban" canister or cartridge based filter systems available. These devices consist of individual canisters or cartridges that filter stormwater runoff by passing it radially or vertically up through various types of media. Many of these devices are part of "drop-in" systems, and incorporate some combination of filter media, hydrodynamic sediment removal, oil and grease removal, or screening to remove pollutants from stormwater (EPA, 2004). Infiltration practices (basins and trenches) are long, narrow stone or gravel-filled excavated trenches. Stormwater runoff is stored in the basin or in a trench, in voids between the stones or gravel, and slowly infiltrates into the soil matrix below. Infiltration devices are normally combined with pretreatment practices such as a grass swales or sediment basins to prevent premature clogging at the soil/water interface (EPA, 2004).
One of the most significant drawbacks to filtration and infiltration systems is premature clogging of the surface due to buildup of solids (Woelkers et al., 2006). Granular media filters and infiltration soils accumulate solids on the top surface that form a layer of crust. Most of the filtration occurs in this layer once it forms, resulting in rapid clogging and a relatively short service cycle. Where possible, treatment systems are vegetated because the presence of vegetation can help breakup this crust layer, and growing roots increase the availability of macropores for water to infiltrate. In industrial and drinking water treatment, filters are backwashed periodically to restore hydraulic flow, or other novel mechanical methods may be used (U.S. Pat. No. 7,163,630). This is not possible in typical stormwater and wastewater filtration and infiltration devices that operate passively (without power) under gravity filtration. These systems therefore require periodic raking or removal of the surface sediment and top layer of media and, after prolonged use, complete replacement of the media layer. In general, the trade off in granular filter design is between using small grain size filter media which improves treatment but results in quicker clogging, and using coarser grain size media which provides poorer treatment but prolongs hydraulic capacity. A major constraint therefore to use of passive filtration and infiltration treatment practices is rapid or premature clogging, which either makes them impractical, such as under high loading rate application, or increases operational and maintenance costs.
The most common method of extending the hydraulic service life of filters and infiltration systems is to provide some level of pretreatment to the contaminated water. This includes removing suspended particles by storing the water for a period of time in a detention basin (sedimentation) or filtering it through an area of vegetation (biofiltration) before treatment by the filter or soil. Although effective, these solutions require additional space for implementation, and are associated with their own maintenance costs. Dual layer filters, in which a coarse grain size media layer is on top of a finer grain size layer, is another technique used to prolong the hydraulic life of filters (Sutherland, 2008; U.S. Pat. Nos. 7,045,067; 5,281,332; 3,876,546). Here, the top coarse layer can be considered a prefilter for the bottom finer layer. During filtration, particles are trapped within the whole depth of the upper layer via "depth filtration" and not just on the surface. Although dual and multilayer granular filters can have longer service runs, premature clogging is still of concern when loading rates are high (Sutherland, 2008), as is the case in urban areas where treatment device size is restricted by availability of space. In addition, use of a coarser upper layer results in a deterioration in the treatment efficiency of the filter. Ultra-urban filter devices incorporate vertical flows or use relatively coarser media or media in pellet form to prevent premature clogging of the media (U.S. Pat. Nos. 7,419,591; 6,649,048; 5,707,527). Other methods used to prolong the hydraulic service life of passive filters include prefiltration through one of more layers of sheet geotextile (Woelkers et al., 2006). Recent prior art suggests adding plastic pellets that are larger than the granular media can also increase the hydraulic capacity of passive filters (U.S. Patent A1 2006/0163136). The prior art clearly indicates a need for novel techniques that can extend the service life of passive filtration and infiltration devices, and thereby reduce the maintenance costs associated with them.
Polymer gels are a class of polymer materials that comprise an elastic network of cross-linked polymers and a solvent. In its dry state, a polymer gel behaves like a solid. When immersed in a solvent, it is able to absorb the solvent and swell, and behaves more like a gel. The properties of a polymer gel mainly depend on the degree of cross-linking, the chemical composition of the polymeric chains, and the interaction between the network and surrounding liquids. Many polymer gels, particularly organic-based polymer gels, can expand or contract and make large reversible changes in volume (up to 1000 times their original size) when they contact and absorb the solvent. There are two groups of polymers that are of interest here: the traditional polymer gels that expand on contact with a solvent and contract when dried; and the stimuli-responsive polymers which only expand or contract in response to certain stimuli. When the solvent is water, these polymers are called traditional hydrogels and stimuli-responsive hydrogels.
Traditional hydrogels have found a wide range of uses in agriculture, food industry, biotechnology, environmental sciences, and other fields. The prior art shows a number of inventions in the field of irrigation and agriculture that claim use of traditional hydrogels. U.S. Pat. No. 4,696,319 describes a moisture-activated apparatus for controlling the flow of water. Expansion on absorption and contraction on desorption of water by a water-swellable material is used to cause the valve stem of the valve to move between closed and open positions. In U.S. Pat. No. 5,303,663, the use of polymers is discussed for effective control and utilization of irrigation water, and the stated advantage is that the technology creates a "blanket" of moisture retaining particles for the plant roots. In one controlled application, it is stated that polymer treated field produces approximately 35% more hay while using 50% less water and 50% less fertilizer than in an adjacent field which had not been treated. U.S. Pat. No. 5,382,270 discusses growing of plants within a medium of hydrogel granules swollen by aqueous nutrient solution. The hydrogel serves to support the plants and the aqueous nutrient medium, which has to be supplemented from time to time, feeds the plants. In this application, the proposed hydrogels expand as they absorb water and plant nutrients.
There is limited prior art on the use of traditional hydrogels in water treatment devices. U.S. Pat. No. 7,501,380 specifies a blended composition of hydrogel polymer granules capable of selectively removing toxic dissolved metal species from water, and spacer particles which minimize contact between contiguous polymer granules for reducing the impedance of water. The invention claimed is a compacted and confined granular filter bed for removing dissolved metals from water. U.S. Pat. No. 5,178,768 proposes a mixed filter bed composition that comprises of various media and about 5% to about 20% by weight of silica hydrogel. The silica hydrogel, which is an inorganic hydrogel, is used to prevent growth of bacteria. U.S. Pat. No. 5,578,213 describes a method of treating wastewater containing particulate matter and free oil, which comprises a series of treatment steps that end with contacting the wastewater with an adsorbent bed to form a purified water stream. The adsorbent bed is claimed to comprise of one or more components selected from the group consisting of carbonous sorbent, activated alumina, silica hydrogel, zeolite, and metallic components. U.S. Pat. Nos. 7,501,380, 5,178,768, and 5,578,213 described above all claim use of chemical properties of traditional hydrogels. There is no prior art on the use of the expansion-on-wetting and contraction-on-drying physical property of traditional hydrogels to help prevent premature clogging in passive treatment devices.
In the last decade, there has been considerable research on a new group of polymers that can respond to changes in environmental conditions such pH, temperature, light, ionic strength, voltage, external pressure, solvent composition, or other stimulus. These stimuli-responsive, intelligent, or smart polymers can reversibly change their physical or chemical properties in response to these environmental stimuli (Roy and Gupta, 2003; Kopecek, 2007). The majority of research on stimuli-responsive polymers has been on stimuli-responsive hydrogels because of their applicability in drug delivery, biomaterials, and biomedical devices such as miniature artificial valves and muscles. Stimuli-responsive polymers typically consist of cross-linked polymer network structure containing the stimuli-responsive component in the polymer chains. When these polymers are stimulated, they will absorb water and expand in size or release absorbed water and contract in size. The prior art on application of stimuli-responsive polymers/hydrogels in water treatment applications is limited to membrane filtration. U.S. Pat. No. 7,316,919 describes one such application, a composite material that comprises a support member with a plurality of pores and, located in the pores of the support member, a macroporous cross-linked gel that can respond to environmental stimulus. The composite material is claimed to be suitable for separation of substances, for example by filtration or adsorption, including chromatography, for use as a support in synthesis or for use as a support for cell growth. There is no prior art on the use of the physical property of reversible expansion/contraction of stimuli-responsive polymers/hydrogels to help prevent premature clogging in passive filtration and infiltration devices.
In conclusion, the prior art shows that clogging of "passive" or gravity flow filtration and infiltration devices is a concern in terms of service life and maintenance costs. Traditional methods to prevent premature clogging, such as pretreatment by sedimentation or use of depth filtration techniques, require additional space, have their own maintenance needs, and do not overcome the need for frequent maintenance when loading rates are relatively high. The prior art shows that use of hydrogels in granular filters has been limited to potential benefits from their chemical properties (e.g. U.S. Pat. Nos. 5,178,768; 5,578,213; 7,501,380). There is no prior art on the use of the physical property of reversible expansion and contraction of stimuli-responsive polymers/hydrogels to help prevent premature clogging in passive filtration and infiltration devices.
This invention claims a new and unobvious use for stimuli-responsive polymers. It discloses a method of filtering contaminated water, such as stormwater runoff and wastewater, through granular filter media or soil to which is added stimuli-responsive polymer particles. The property of these stimuli-responsive polymers that makes them suitable for reducing the rate of clogging in passive treatment devices is the large and reversible change in volume in response to certain environmental stimuli. The expansion and contraction of the polymer particles in response to certain environmental conditions will increase creation of macropores that improve depth filtration, and help physically break up the sediment buildup that causes hydraulic failure. This invention replicates the observed benefits of vegetation and roots in increasing macropore structures and preventing premature clogging. The benefit of this invention over prior art is reduced maintenance needs and associated costs because the method increases service life.
The method comprises passing the contaminated water through a layer of material comprised substantially of filter media and stimuli-responsive polymer particles. The filter media is selected from the group consisting of granular filter media and soil. The stimuli-responsive polymer particles further have a predetermined size and shape and are capable of undergoing a reversible volume change in response to a change in one or more environmental conditions. The environmental conditions include temperature, pH, water composition, light intensity, light wavelength, electric field, magnetic field, pressure, and ionic strength wherein occurrence of at least one of the environmental conditions causes the stimuli-responsive particles to expand or contract, wherein expanding and contracting the stimuli-responsive particles in response to the environmental conditions results in an increase in macropores in the layer of material and breaks up of sediment and crust that would otherwise reduce hydraulic flow through the layer of material. The contaminated water can be stormwater runoff or wastewater. The stimuli-responsive polymer particles can be spherical, cylindrical, or tubular shape, and can be solid or hollow. The granular filter media is selected from the group consisting of sand, perlite, limestone, dolomite, gravel, soil, and other natural media. The granular filter media can also be selected from the group consisting of activated carbon, coated sand, and other manufactured media. The granular media can be a mixture of two or more different media.


A liquid ink repellent coating adapted to prevent transfer of fluid image forming ink droplets between imaged sheets in a stack of multiple printed impressions. The repellent coating comprises a polymeric composition having a surface energy less than about 30 mJ/m2 and an insoluble particulate filler as a matting agent.

The invention relates to coatings applied to film materials to provide receptor elements for images generated by inkjet printers. More particularly, the invention relates to films having an inkjet image receptor coating on one side and an ink repellent coating on the other to allow contact between a plurality of imaged sheets, during printing, without smearing of ink droplets before an image dries.
Printing methods, including inkjet printing and electrophotographic or laser printing have achieved widespread acceptance, for home and office use, to print text and graphic images on a variety of receptor substrates such as paper and films. The films may be used as transparency film for overhead projectors. Inkjet printers are well suited for use with paper substrates that rapidly absorb the image forming ink droplets, drawing them away from the paper receptor surface into the fibrous bulk of the sheet. Migration of the ink droplets into the paper sheet prevents lowering of image quality that could occur if a still-wet image was smeared in some way.
Film materials, unlike paper, have no inherent capacity to absorb inks that are commonly used in inkjet printers. The capture of the image-forming ink droplets on transparency film presents a technical challenge because plastic film is substantially impervious to liquids. A conventional way for forming an ink-receptive surface involves coating the surface of the film with an ink receptive layer. Typically a hydrophilic coating (the ink receptive layer) absorbs ink droplets to minimize loss of image definition that maybe caused by ink migration or bleeding across the film surface.
Hydrophilic coatings, applied to film materials, are known to provide receptor layers for inkjet images. Receptor layers of this type may be porous for absorbing ink droplets via capillary action. Such coatings are described, for example, in U.S. Pat. No. 5,264,275. An alternative type of absorbent inkjet receptive coating comprises polymers that swell while absorbing image forming ink droplets. Such coatings include those described in U.S. Pat. Nos. 3,889,270, 4,503,111, 4,564,560, 4,555,437, 4,379,804, 5,134,198 and 5,342,688. Hydrophilic inkjet-receptive coatings may also include multilayer coatings as described in U.S. Pat. No. 4,379,804.
In addition to an inkjet image receptor coating, a film sheet of inkjet printable media may require further treatment to control the physical properties of the sheet such as surface roughness, static charge accumulation, and curl-set. Backside coatings, opposite the ink receptive coating, may provide surface roughness to assist sheet feeding through the transport rollers of an inkjet printer. Application of antistatic coatings and related treatments curtail the accumulation of static charge that may cause feeding and stacking problems between sheets. A very common function of backside coating on inkjet receptive sheets is control of curl. Under low humidity conditions the ink-receptive coating may lose water to the atmosphere, resulting in overall shrinkage of the layer. This places consequent stress on one side of a flexible substrate causing the film to adopt a curl-set usually towards the image-bearing surface. Therefore it has become common practice to coat a hydrophilic, moisture absorbing coating on the backside of the flexible substrate to counteract the image-side curl. The backside coating may, itself, be an inkjet receptive layer, such that the construction is symmetrical having no preferred orientation during deposition of an inkjet image.
US Patents, including U.S. Pat. Nos. 6,022,677, 5,916,673 and 5,723,211, describe inkjet media backside coatings for controlling physical properties as discussed above. Many of these backside coating formulations were developed for paper and other opaque substrates and may be unsuitable for transparency film applications, especially if the coating itself is not completely transparent.
Improvements in inkjet image receptive coatings and physical property control of text and graphic image recording plastic sheets has allowed an increase in the sheets-per-minute output of inkjet printers. A continuing constraint on the print speed for relatively impervious substrates, such as plastic film, is the rate of image forming droplet absorption by the ink receptive layer. Inkjet printers generally stack the printed output copies, automatically, into an output tray. If the image on one sheet is not dry to the touch before release of a following sheet into the output tray, ink from the wet image, will often transfer to the backside of the next overlying sheet in the stack.
The problem of image transfer between relatively impervious sheets becomes more severe when the sheet is a transparent film bearing text and graphic images for presentation using an enlarging projector, such as an overhead projector. Images deposited on transparency film usually will be high contrast images to avoid the appearance of a washed-out projected image focused on a projection screen. High contrast images may require a higher ink loading to achieve optimum optical density compared to images deposited against a white background such as paper that is viewed by reflected light. As might be expected, the higher ink loading requires a longer drying time. Delayed drying potentially leads to an increasing amount of image transfer or offset between adjacent sheets. For this reason, manufacturers of inkjet printers have generally found it necessary to slow the print rate when printing film transparencies for projection.
In view of the above described deficiencies associated with the use of known inkjet image receptor films, particularly offset of the image formed by ink droplets, the present invention has been developed to alleviate these drawbacks and provide further improvement. These enhancements and benefits are described in greater detail hereinbelow with respect to several alternative embodiments of the present invention.
In its several disclosed embodiments, the present invention alleviates the drawbacks described above with respect to impervious films containing coatings that provide receptor elements for inkjet images. Of particular interest is the use of dissimilar coatings on opposing sides of image receptor sheets. Differences in these coatings minimize, if not deter ink transfer, also referred to herein as image offset, between adjacent surfaces of sheets of a stack produced in the output tray of a printer during inkjet printing.
In a majority of printing and copying methods, the printing equipment used to produce multiple impressions establishes precise positioning of a receptor sheet for image transfer before ejecting the sheet into an output tray. The orientation of the ejected sheet usually places the recently applied image pattern on the exposed, upward facing surface of the sheet. The next sheet to be ejected from the printing equipment may slide across the exposed imaged surface before settling over the previous sheet. With continued operation of a printer, a stack of sheets will form having upward-facing, imaged surfaces in contact with the downward facing surface or backside of the next higher sheet in the stack. The upward-facing image may not be in a fully fixed or in a permanent condition before contact with the backside of the next sheet in the printing sequence. This condition is especially true for inkjet images produced by image forming droplets. Sliding contact between sheets exiting the inkjet printer may cause smearing of still-wet images. Also, contact of adjacent sheets in a stacked configuration may lead to ink transfer or smearing, due to ink migration across the interface between an imaged surface and the backside of its nearest neighbor. Use of coated films according to the present invention substantially eliminates image smearing and image offset problems that occur by ink migration between sheets. Reduction or elimination of ink migration involves applying a non-wetting or ink-repellent coating to the backside of the film. Such coatings were discovered also to be beneficially receptive to toner powders used with electrophotographic printers. This discovery resulted in the development of a dual-purpose receptor element suitable for use with both inkjet and electrophotographic printers.
In brief summary, the present invention provides an image receptor sheet comprising (a) a substrate having first and second surfaces, (b) an ink-receptive coating disposed on the first surface, and (c) an ink repellent layer disposed on said second side to prevent transfer of ink from said first side to said second side, said ink repellent layer comprising (i) a polymeric composition having a surface energy less than about 30 mJ/m2; and (ii) an insoluble particulate filler as a matting agent. In one embodiment, the ink repellent coating is also toner powder receptive thus allowing the image receptor sheet to be used in electrographic printers. Each of these components is discussed below in detail.
Substrates
Manufacture of the inventive image receptor sheets includes the selection of a substrate for coating on one side with an ink receptive single or multilayer coating and on the other side with a non-wetting, ink repellent single or multilayer coating. For use as image sheets with projection equipment the substrate and coated layers will be substantially transparent, meaning that it transmits light of about 400 to 700 nm in wavelength. The substrates are preferably substantially impervious to liquids, such as inks. In this document, the term xe2x80x9caboutxe2x80x9d shall be assumed to modify numerical values, such as dimensions, time, temperature, percentages, whether expressly stated or not.
Suitable substrates include a wide range of flexible plastic films including cellulose esters such as cellulose triacetate or diacetate, polystyrene, polyamides, vinyl chloride polymers and copolymers, polyolefin and polyallomer polymers and copolymers, polysulphones, polycarbonates, and polyesters. The substrates are 50 to 125 micrometers in thickness. Preferred film substrates are cellulose triacetate or cellulose diacetate, polyesters, especially poly(ethylene terephthalate), and polystyrene films, with poly(ethylene terephthalate) having a thickness of 105 to 125 micrometers being most preferred.
When polyester or polystyrene substrates are used, they are preferably biaxially oriented, and may also be heat set for dimensional stability during fusion of the image to the support. These films may be produced by any conventional method in which the film is biaxially stretched to impart molecular orientation and is dimensionally stabilized by heat setting.
To promote adhesion of the ink-receptive layer to the substrate, it may be desirable to treat the surface of the substrate with one or more primers, in single or multiple layers. Useful primers include those known to have a swelling effect on the substrate. Examples include halogenated phenols dissolved in organic solvents. Alternatively, the surface of the film backing may be modified by treatment such as corona treatment or plasma treatment. The primer layer, when used, should be relatively thin, preferably less than 2 micrometers, more preferably less than 1 micrometer, and may be coated by conventional coating methods.
Ink Repellent Coating
A distinguishing feature of the present invention relates to the use of a non-wetting surface coating that substantially repels a wide range of fluid compositions thereby preventing their transfer to the non-wetting surface. Repulsion of a fluid medium at a given surface depends upon the surface tension of the fluid and the surface energy of the material with which the fluid may come into contact. For the fluid to migrate towards the surface, the fluid first wets the surface then shows a tendency to spread over it. Spreading tendency may be indicated by the contact angle of the fluid with a surface. Relatively low contact angles indicate wetting, while measurement of relatively high contact angles coincides with poor surface wetting and the possible formation of beads of fluid that have little affinity for the surface to which they are applied.
Surfaces exhibiting low surface energy, below about 30 mJ/m2, preferably below 25 mJ/m2, tend to repel both aqueous and solvent-based fluids. The term xe2x80x9csolventxe2x80x9d refers herein to solvents used in inkjet compositions. Coatings then become discontinuous layers with substantial beading of liquid droplets. Liquids responding in this way may be easily removed, without leaving any surface residue, because they have little affinity for the surface. This condition is desirable to prevent the transfer of image forming droplets of inkjet ink. As previously discussed, a sheet having an upward facing imaged surface in contact with a backside of the next higher sheet produces an interface including an ink receptive surface separated from a non-wetting surface when the backside comprises an ink repellent coating. Image forming liquid droplets may span the gap between the ink receptive and ink repellent surfaces. The ink droplets may contact both sides of the interface. Because the backside coating has sufficient repellency, there will be no ink transfer during contact of a still-wet inkjet image with the backside of an adjacent neighboring sheet. Addition of insoluble particles, such as polymeric microspheres, to backside coatings appears to further reduce the tendency the transfer of wet inkjet images across the interface between adjacent imaged sheets.
It is known that inkjet ink formulations contain amounts of solvents, ionic solutes, surfactants and the like to facilitate image deposition on a wide range of substrates. Such formulations can complicate the preparation of the inventive image receptor sheet, according to the present invention. The image receptor sheet has an ink repellent coating that exhibit substantially no spreading tendency. U.S. Pat. No. 5,624,747 discloses useful and suitable low surface energy coatings.
Non-wetting, ink repellent backside coatings according to the present invention have surface energies less than about 40 mJ/m2, more preferably less than 35 mJ/m2, and most preferably less than 30 mJ/m2. Surface energy testing can be accomplished according to a test method described herein. Selection of a fluid repellent coating takes into account its surface energy relative to the surface tension of inkjet inks. Such inks exhibit surface tensions in the range 30 to 50 dynes per cm, more commonly 35 to 45 dynes per cm.
Suitable ink repellent coatings may be manufactured from water insoluble polymers, especially polymers containing hydrocarbon groups, silicon atoms or fluorine atoms or combinations thereof. Useful ink repellent coatings are release coatings that exhibit low surface energy and maintain their chemical structure when exposed to inkjet inks. Particularly useful are repellent coatings include (a) water borne urethane release coating such as the class of polymers described in U.S. Pat. No. 5,990,238 (DiZio et aL), (b) urethane release coating such as the class of polymers disclosed in U.S. Pat. No. 2,532,011 (Dahlquist), (c) silicone polyurea release coating such as the class of polymers described in U.S. Pat. No. 5,290,615 (Tushaus et al), and (d) combinations thereof. In a preferred embodiment, the ink repellent coating is transparent and has a dry coating thickness of less than 10 micrometers, preferably 2 to 3 micrometers.
U.S. Pat. No. 5,990,238 discloses a release coating composition that includes a polymer containing a polyethylene backbone having substituents attached thereto. Preferably, the substituents include a urethane linked nitrogen-bonded hydrocarbon side chain having about 5 carbon atoms or more in length and a terminal methyl group; and an oxygen linked water solubilizing group. The substituents may further include hydrogen; a hydroxyl; a halide; an alkylene, an alkenylene, an alkynylene, an arylene group, or mixtures thereof, having a terminal hydroxyl group;
xe2x80x94Oxe2x80x94R5;xe2x80x94R6; or mixtures thereof; wherein each R4, R5, and R6 is independently selected from the group of an aliphatic group, an aromatic group, and mixtures thereof.
A water solubilizing group is a functionality capable of being ionized or is the ionized form thereof, which can either be anionic or cationic. For example, the water solubilizing group may include an acidic group capable of forming an anionic species. Preferably, when the water solubilizing group contains an anion, it is selected from the group of xe2x80x94OSO2Oxe2x88x92, xe2x80x94SO2Oxe2x88x92, xe2x80x94CO2xe2x88x92, (xe2x80x94O)2P(O)Oxe2x88x92, xe2x80x94OP(O) (Oxe2x88x92)2, xe2x80x94P(O)(Oxe2x88x92)2, xe2x80x94P(Oxe2x88x92)2, and xe2x80x94PO(Oxe2x88x92)2. Equally preferable is a water solubilizing group containing a cation selected from the group of xe2x80x94NH(R8)2+ and xe2x80x94N(R8)3+, wherein R8 is selected from the group of a phenyl group; a cycloaliphatic group; and a straight or branched aliphatic group having about 1 to 12 carbon atoms.
The release coating composition of U.S. Pat. No. 5,990,238 may be coated from an organic solvent, water, or mixtures thereof. Thus, the release coating composition may contain organic solvents, preferably selected from the group of an aromatic hydrocarbon, an ester, an aliphatic hydrocarbon, an alcohol, a ketone, and mixtures thereof; or it may contain water.
U.S. Pat. No. 5,290,615 provides release coating of organosiloxane-polyurea block copolymers, which are segmented copolymers of the (AB)n, type. They are obtained through a condensation polymerization of a difunctional organopolysiloxane amine (which produces soft segment), with little contamination from monofunctional or nonfunctional siloxane impurities, with a diisocyanate (which produces a hard segment) and may include a difunctional chain extender such as a difunctional amine or alcohol, or a mixture thereof. For a specific description of the block copolymer, see U.S. Pat. No.5,290,615 at column 1, line 67 to column 2, line 42. Methods of making the block copolymer are also disclosed.
Ink Receptive Coatings
Inkjet ink receptive coatings may comprise one or more layers of any suitable hydrophilic polymer or blend of polymers including, substituted polyurethanes, polyvinyl alcohol and substituted polyvinyl alcohols, polyvinyl pyrrolidone and substituted polyvinyl pyrrolidones, vinyl pyrrolidone/vinyl acetate copolymer, vinyl acetate/acrylic copolymers, acrylic acid polymers and copolymers, acrylamide polymers and copolymers, cellulosic polymers and copolymers, styrene copolymers of allyl alcohol, acrylic acid, maleic acid, esters or anhydride, and the like, alkylene oxide polymers and copolymers, gelatins and modified gelatins, and polysaccharides. Preferred hydrophilic polymers include polyvinyl pyrrolidone and substituted polyvinyl pyrrolidones; polyvinyl alcohol and substituted polyvinyl alcohols; vinyl pyrrolidone/-vinyl acetate copolymer; vinyl acetate/acrylic copolymer; polyacrylic acid; polyacrylamides; alkylhydroxyalkylcellulose; carboxyethylcellulose; gelatin; and polysaccharides.
Secondary additives may be incorporated into the inkjet receptive coating. Illustrative additives include, but are not limited to, mordants, water insoluble particles, plasticizers, antistatic agents, fade inhibitors (for image color brightness), fillers, crosslinking agents and antimicrobial agents.
Mordants may be used to control dye diffusion. Typical mordants include cationic materials such as amines and substituted amines, including quaternary ammonium salts. U.S. Pat. No. 5,342,688 (Kitchen et aL) discloses a useful polymeric mordant comprising a guanidine functionality as described throughout the patent, e.g., from column 3, line 32 to column 4, line 16.
Water insoluble particles are known for use as matting agents to control the frictional characteristics of image receptor sheets for reliable sheet-feeding through printing equipment. Suitable particulate materials may be derived from organic polymers such as polymethylmethacrylate; polystyrene; polyureaformaldehyde; and starch powders; and inorganic materials including silica; alumina; and metal silicates.
Plasticizers can be used to control the tendency of the coating to curl at low humidity. Illustrative plasticizers include, but are not limited to, polyethylene glycols, polyhydric alcohols, reduced sugars and the like.
Antistatic agents such as CYASTAT 609 or CYASTAT SN (available from American Cyanamid) prevent static charging of the film.
Fade inhibitors may be used to stabilize the image dyes against degradation with time. Suitable fade inhibitors include antioxidants such as IRGANOX 1010 available from Ciba Geigy.
Fillers may be used to modify the mechanical properties of the coating, provided that such materials do not compromise the transparency of the layer. Suitable materials include colloidal silica and alumina.
Crosslinking silanes, aziridines and the like may be used to modify the mechanical properties of the coating.
Antimicrobial agents such as ACTICIDE MV available from Actichem Inc. may be incorporated into the receptor layer.
Test for Surface Energy
The surface energy (in units of millijoules per square meter, mJ/m2) is calculated from the measured advancing contact angles of water and methylene iodide and the known surface tensions of these liquids, using the geometric mean equation, as described in Souheng Wu, Polymer Interface and Adhesion, p. 178-181, 1982, published by Marcel Dekker, Inc.
Contact angle measurements were made using the sessile drop method with a Ramxc3xa9 Hart goniometer equipped with an environmental chamber. Water and methylene iodide used for contact angle measurements were distilled. Advancing contact angles were obtained by increasing or decreasing the drop volume until the three-phase boundary moved over the coating surface. The capillary pipette of the microsyringe was kept immersed in the drop during the measurement. The contact angle was the averages of measurements made on 4 to 6 different drops.


The present invention is directed to a fluid fitting coupling system. This system has first and second fluid assemblies, and first and second rotationally engagable axial retainers. The first and second fluid assemblies each have a fluid fitting body, a central axis, a fluid passageway, a mating component for rotation, and a movable sealing apparatus. While the first and second rotationally engagable axial retainers each have an opening for a fluid to traverse there through. The fluid fitting coupling system operates when the second rotationally engagable axial retainer engages and rotates, in a first direction, the first rotationally engagable axial retainer. In response, the first and second mating components rotate the respective first and second fluid fitting in a direction opposite the first direction so the movable sealing apparatuses are spaced a distance from the respective openings.

This invention relates generally to fluid fittings. Specifically, it involves the field of molded coupling systems for quickly connecting and disconnecting fittings which handle fluids.
The couplings generally consist of a male member and a female member with sealed fluid passageways connecting therebetween. The female member generally is a cylindrical body with a relatively large diameter longitudinal bore at one end and a relatively small diameter longitudinal bore at the other end. The small bore facilitates connections to hydraulic or fluid lines, while the large bore seals and slidingly engages the male member of the coupling.
The male member includes a cylindrical body having an outer diameter approximately equal to the diameter of the large female bore, and a connection at its other end for hydraulic lines. When the cylindrical body of the male member is inserted into the large bore of the female member then fluid flow is established between the male member and the female member. In some embodiments, it is preferable to connect the male member to the female member by sliding it into the large bore of the female member, without rotation or other manipulation of one or both coupling members.
The male member or female member may be connected to a junction plate of a manifold. The male or female member may be attached to the junction or manifold plate using various means such as set screws or threads. In some cases, the male member is attached to one junction or manifold plate, while the female member is attached to an opposing plate so as to face the male member and align with it.
The fluid fitting coupler is one which has existed for years. As more economical products have been sought the desire to adapt designs for injection molding has increased. In the majority of instances this adaptation has occurred by merely molding existing designs. In only limited instances have those products sought to create completely new designs which are especially adapted to a molding environment, that is, where a cavity shape is imparted to some type of material. One of the fields within this general area which has been particularly challenging to adapt for economical manufacture is that of fluid fitting quick disconnects. Often due to this field""s sometimes unusual material requirements, it has been perceived as requiring a hybrid approach. Through this approach, while some components have been molded, others have been machined or the like. Thus, rather than being optimized for economical manufacture such as is available in the injection molding environment, designers often have accepted limitations in either operation or manufacture.
Naturally, the problems designers have faced are greatly varied based in part upon the application involved. In some applications, the physical size of the quick disconnect designs have been a challenge. In other applications, reliability and the actual operation of coupling the two assemblies together has been the challenge. Other problems have ranged from challenges in achieving adequate locking of the coupling to problems in creating shut-off valve subassemblies. Irrespective of the specific operational problems deemed paramount, it has been almost universally true that existing designs have not been able to be manufactured as economically as desired. In spite of a demand for high reliability and ease of use, consumers have been reluctant to incorporate components which cost many times the amount of a typical fitting.
As is often true for fluid fittings in general, many aspects of the invention utilize elements which have long been available. In spite of this fact, and in spite of the fact that those skilled in the art of molded fluid fitting couplings had long desired such a design, the invention applies these elements in a fashion which achieves long felt needs very economically.
Sampson, in U.S. Pat. No. 5,937,885, discloses a quick disconnect fluid fitting coupling system which can not only be completely molded but which also can consist of as little as two parts. In one embodiment, the design involves male and female assemblies which are held axially by a flange and which lock in place through a radially resilient detent at the flange""s outer abutment. Another embodiment includes a molded annular spring which locks the two assemblies together. A number of other features such as swivels and shut-off valves are also disclosed.
The Sampson devices, however, require components that are difficult to manufacture and require components, like springs, that are extremely breakable and/or deformable.
The present invention solves those problems and many more. The present invention is directed to a fluid fitting coupling system. This system has first and second fluid assemblies, and first and second rotationally engagable axial retainers. The first and second fluid assemblies each have a fluid fitting body, a central axis, a fluid passageway, a mating component for rotation, and a movable sealing apparatus. While the first and second rotationally engagable axial retainers each have an opening for a fluid to traverse there through. The fluid fitting coupling system operates when the second rotationally engagable axial retainer engages and rotates, in a first direction, the first rotationally engagable axial retainer. In response to the insertion and rotation of the retainers, the first and second mating components rotate the respective first and second fluid fitting in a direction opposite the first direction so the movable sealing apparatuses are spaced a distance from the respective openings for fluid to flow within the system.


During the winding of the layers of the wires of a tire bead ring, a piece of ribbon is interposed at least twice per revolution between two consecutive layers of wires, the ribbon being formed of a thin flexible support bearing on each of its faces a layer of a material which adheres both to the support and to the wires.

The present invention relates to bead rings of package type reinforcing the beads of tires and produced by winding wires, preferably metallic wires of rectangular cross-section, over a body of revolution.
The present invention applies in particular to bead rings of the type mentioned above whose radially inner face is frustoconical and smooth, and which are manufactured by the process described in French Patent No. 2,456,610 (which corresponds to U.S. Pat. No. 4,305,769). This process consists essentially in imparting a permanent deformation to the steel wire by means of a suitable deviated flexion before it is wound on the manufacturing form. Thus, the wires which are juxtaposed in the same layer and superposed from one layer to the next are duly aligned with each other. As a result, therefore, the wires which have been treated in this way are free of residual elastic stresses and no longer have a tendency to unwind by themselves.
However, it is still necessary to assure the coherence of such a bead ring during the course of the handling of it, from the time when it is removed from the manufacturing form until the time that it is incorporated in the bead of the tire by the manufacturer of the latter, without loss of its flexibility or its resistance to rupture.
For this reason, in accordance with the present invention, in order to produce a package bead ring for tires having a rectangular radial cross-section and therefore a rectilinear radially inner face and formed of at least two layers of at least two adjacent wires, preferably metallic wires, of rectangular cross-section wound alongside each other from layer to layer and from wire to wire on a manufacturing form after permanent bending of the wires, there is used a process which is characterized by the fact that during the winding of the layers of wires a piece of ribbon, which is formed of a thin flexible support resistant to shear in the radial direction between two adjacent wires and which is of a thickness at most equal to 0.5 mm and preferably less than 0.3 mm, is interposed at irregular or regular intervals at least twice per revolution between two consecutive layers of wires, the support bearing on each of its faces a layer of a material which is adherent both to the support and to the wires.
Within the scope of the present invention, the support is formed of a film of paper or of either synthetic or metallic material, of a fabric (weft and warp) or of fibers or filaments oriented perpendicular to the direction of winding of the layers of wires on the manufacturing form for the bead ring, provided that the thickness of this support is at most equal to 0.5 mm and preferably less than 0.3 mm.
It is known to interpose a continuous layer of rubber solution between the turns of a bead ring formed by winding a wide steel ribbon (French Patent No. 1,281,439). The purpose of such a gluing is to avoid the sliding of the turns on each other, in particular upon the shaping of the tire into toroidal shape. However, the continuity of the layer of glue weakens the rupture load of such a bead ring, as has been shown by the research work of the applicant.
The present invention, by contrast, preserves not only the flexibility of the bead ring, as opposed to continuous gluing, but also the rupture load of the bead ring, which is the object of the improvement claimed, due to the slight thickness of the ribbons and their ratio to the surface of a layer of wires. Within the scope of the present invention, the total active surface of the pieces of ribbons interposed between two consecutive layers of wires is between 0.5% and less than 20% of the surface of one layer of wires counted over one revolution (length of one turn times width of one layer). Upon the winding of the layers of wires on the manufacturing form and the emplacing of the pieces of ribbon, it is preferable to provide for a staggering of the pieces of ribbon in the direction of the winding from one layer of wires to the next. In this way one avoids local excess thicknesses which are prejudicial to the rupture load of the bead ring and to the geometrical uniformity of its cross-section.
The thinness of the support of the pieces of ribbon in accordance with the invention, on the one hand, avoids the infiltration of the rubber between the wires and the layers of wires of the bead ring upon the vulcanizing of the tire and, on the other hand, assures that there is intimate contact between consecutive layers of wires over practically the entire surface of the wires. One thus assures the geometry of the bead ring without detriment to its rupture load.

Process for holding together the wires of a package bead ring for tires

Compagnie Generale des Etablissements Michelin


Multiple Network Attached Storage (NAS) appliances are pooled together by a virtual NAS translator, forming one common name space visible to clients. Clients send messages to the virtual NAS translator with a file name and a virtual handle of the parent directory that are concatenated to a full file-path name and compressed by a cryptographic hash function to generate a hashed-name key. The hashed-name key is matched to a storage key in a table. The full file-path name is not stored, reducing the table size. A unique entry number is returned to the client as the virtual file handle that is also stored in another table with one or more native file handles, allowing virtual handles to be translated to native handles that the NAS appliance servers use to retrieve files. File movement among NAS servers alters native file handles but not virtual handles, hiding NAS details from clients.

Both supply and demand for computer disk storage have increased sharply in the last decade. Computer hard-disk technology and the resulting storage densities have grown even faster than in the semiconductor field, at times exceeding Moore's Law projections. Despite application-program bloat and wider use of large multimedia files, disk drive storage densities have been able to keep up.
Widespread use of networking has allowed for greater file sharing. Rather than store data files on individual users' personal computers (PCs), many companies and organizations prefer to have important files stored in a centralized data storage. Important data can be regularly maintained and archived while being available for sharing among many users when stored in central storage.
Storage Area Networks (SANs) are widely used by large corporations as such a centralized data store. FIG. 1 shows a SAN. SAN bus 22 is a high-speed bus such as a FibreChannel that connects to many disk arrays 20, 20′, 20″. Often Redundant Array of Independent Disks (RAID) is used to mirror data stored on the disks for greater reliability. RAID controllers 18, 18′, 18″ can be inserted between disk arrays 20, 20′, 20″ and SAN bus 22.
Clients such as application layer 10 generate disk accesses through client operating system 12, which in turn uses file system 14 to access stored data. FibreChannel controller 16 receives requests and performs physical transfers of block data over SAN bus 22.
SAN bus 22 transfers data as blocks rather than as files. File system 14 converts requests for data files into the block addresses needed for accessing the data on disk arrays 20, 20′, 20″. An individual file can be stored on several blocks of data that are stored on any of disk arrays 20, 20′, 20″.
Since SAN bus 22 performs block transfers, there is no high-level file-system controller on disk arrays 20, 20′, 20″. Instead, disk arrays 20, 20′, 20″ act as network-connected disk drives. SAN bus 22 can operate with special protocols that are designed to maximize data transfer rates of lower-level blocks of data. Thus SAN bus 22 is a specialized bus. SANs tend to be very expensive and are usually not cost-effective for smaller organizations.
Another widespread storage technology is Network Attached Storage (NAS). NAS is less expensive than SAN and uses standard Transport-Control-Protocol Internet Protocol (TCP/IP) network buses rather than a specialized SAN bus. NAS appliances are usually single-box devices such as LINUX or Windows systems that can easily be connected to a TCP/IP network.
FIG. 2 shows use of NAS and the NAS creep problem. Network bus 32 is a standard TCP/IP network bus. Client application layer 10 requests file accesses through operating system 12, which uses network-file-system (NFS) 28 to generate file request messages that are encapsulated by TCP/IP and any lower-level network protocols and sent over network bus 32 to NAS appliance 21.
NAS appliance 21 processes the message received over network bus 32 using server NFS 26, which sends the request to file system 14. File system 14 looks up the file name and finds the file handle, which is returned to application layer 10. Future requests for the data can be made by using this file handle.
File system 14 can access requested data through small-computer system interface (SCSI) controller 24 or another kind of controller to access disk arrays 20. RAID controllers 18 may be used for redundant data storage, or may be omitted.
NAS appliance 21 is easy to install and maintain, since it is connected to network bus 32 much like any other networked PC. Network bus 32 carries NFS messages encapsulated by standard TCP/IP packets, which can be the already-existing network in an organization that the client PCs are already attached to. File names and file handles are transferred over network bus 32 in the NFS messages rather than block addresses.
One problem with NAS appliance 21 is upgrading to larger storage or faster processing capacities. As its workload increases, the processor on NAS appliance 21 may no longer be able to handle all requests. Additional disks may initially be added to NAS appliance 21, but once all disk bays are populated, no more disks can be added. Instead, a second NAS appliance 21′ may need to be installed on network bus 32. New data could be stored on NAS appliance 21′. However, it is difficult to move data among NAS appliance 21 and NAS appliance 21′. This is because clients have to mount to NAS appliance 21′ as well as to NAS appliance 21′. Additional mount requests to NAS appliance 21′ have to be added to startup scripts for all clients. Data moved to NAS appliance 21′ is found on a different mount point, so clients have to use the new location to find the data. NAS appliance 21 and NAS appliance 21′ appear as two different file systems, with different mount names. Each NAS appliance 21, 21′ has its own name space.
It is very undesirable to have to change client software to reflect the new path to NAS appliance 21′ when a file is moved from NAS appliance 21 to NAS appliance 21′. Users may have to know that the file is now accessible under a different mount-point. Applications, scripts, and shortcuts must be edited to refer to the new mount-point. It can be an administrative nightmare to notify users and change existing software and scripts when a file is moved from one name space to another. Thus moving the file is not transparent to the client users.
This is known as the NAS creep problem. It occurs when the NAS appliance 21 fills up and files have to be moved to a different NAS appliance 21′, or when an additional server is installed for performance or other reasons.
FIG. 3 shows SAN combined with NAS. Client application layer 10 still sends NFS messages over network bus 32 to the NAS server, which has NFS 26 decode the messages and use file system 14 to look up file handles. Data requests for file data are converted to block addresses and sent over SAN bus 22 by FibreChannel controller 16. The data is accessed by disk arrays 20, 20′, 20″ and returned as block data that must be re-arranged to generate the data file.
While using a SAN with a NAS could allow for expandability, SAN bus 22 is often a FibreChannel or other very expensive bus, negating the cost advantage of NAS. Protocols such as FibreChannel or iSCSI may be used. FibreChannel Hardware tends to be expensive, while iSCSI tends to be expensive to maintain with the required drivers, etc. A SAN virtualization switch may also be needed.
Some client file systems may allow for directories to reside on different servers in one virtual space. The client file system transparently redirects client accesses to different physical servers when moving to a directory on a different server. However the granularity of re-direction is the directory rather than the file. File granularity rather than directory granularity is preferable for most file-systems.
What is desired is a Network Attached Storage (NAS) system that is expandable and upgradeable and does not use a SAN bus. File-level granularity and virtualization is desirable without altering file systems on existing NAS servers. A virtual NAS is desired that has a compact table storing meta-data on a per-file basis.

Storing lossy hashes of file names and parent handles rather than full names using a compact table for network-attached-storage (NAS)


A gunstock system is disclosed for use with a gun action and a gun floorplate of a gun. The gunstock system comprises a gunstock having a buttstock portion, a midstock portion, and a forestock portion, with the gunstock defining a cavity. The system further includes an insert assembly removably positionable in the cavity of the gunstock. The insert assembly has a top surface contoured to engage a gun action, and a bottom surface contoured to engage the gun floorplate.

1. Field of the Invention
The present invention relates to gunstocks and more particularly pertains to a new gunstock with modular insert for providing a highly versatile gunstock that may be used with a plurality of gun mechanisms by simply changing a modular insert utilized with the gunstock and without having to alter or modify the gunstock to fit the gun mechanism.
2. Description of the Prior Art
Firearms employing gunstocks, such as rifles and shot guns, are extremely popular with hunters and other sportsmen. Since the gunstocks form a large portion of the firearm and also provide the primary point of gripping the firearm by the user when carrying and using the firearm, it has become fairly common to provide the gun owner with a variety of options for gunstocks in both the aftermarket and the original equipment manufacturer (OEM) markets for these firearms and their accessories.
As the gunstocks are a major factor in the appearance of the firearm, as well can enhance the comfort in using the firearm, gunstocks are produced using a variety of different materials and with a variety of different exterior contours. Firearms employing gunstocks are produced by many different manufacturers, with each manufacturer possibly producing several different models using mechanisms with different sizes and shapes. As a result, the variety of different gunstock sizes and shapes and different firearm mechanism configurations results in a multitude of possible combinations of gunstocks that may be needed to be produced to address even a fraction of the gunstock market.
Thus, manufacturers of gunstocks face the dilemma of trying to design, manufacture and maintain an inventory of this multitude of different gunstock permutations (which can be expensive) or simply manufacture the gunstocks on an as-needed basis (which can cause delays in supplying the customer as well as the various outlets with the particular style of gunstock).
Therefore it is believed that there is a need for a gunstock system that may be used with a plurality of different gun mechanisms, or that may be readily adaptable for use with different gun mechanisms.


One embodiment of the present invention discloses a system for use with a downhole tool while perforating deviated portions of subterranean wellbores. The system involves a swivel connection attaching subsequent segments of the downhole tool which increases the overall flexibility of the downhole tool. The swivel connection allows sections of the downhole tool to pivot with respect to the next adjacent section.

1. Field of the Invention
The invention relates generally to the field of oil and gas well services. More specifically the present invention relates to a system that provides flexibility between adjacent segments of a downhole tool to enhance use of the downhole tool in deviated or slanted wells.
2. Description of Related Art
When perforating guns, are used in slanted or deviated wellbores it is often important that the tool be in a specific radial orientation. For example, orienting perforating guns in deviated wells enables the well operator to aim the shaped charges of the perforating gun at specific radial locations along the circumference of the wellbore. This is desired because the potential oil and gas producing zones of each specific well could exist at any radial position or region along the wellbore circumference. Based on the presence and location of these potential producing zones adjacent a deviated well, a well operator can discern a perforating gun orientation whose resulting perforations result in a maximum hydrocarbon production. Not only could a perforation aimed at the wrong angle not result in a preferred hydrocarbon production, but instead could produce unwanted sand production from the surrounding formation into the wellbore.
Numerous attempts have been made to overcome the problem of orienting downhole tools. These attempts include eccentrically weighting downhole tools to rotate in a certain manner or by adding external fins to the tool body to force the tool into a predefined position. Some of these can be found in U.S. Pat. Nos. 4,410,051, 4,438,810, 5,040,619, 5,211,714, 4,637,478, 5,603,379, and 5,964,294.
Many downhole tools, including perforating guns, comprise multiple elongated bodies joined end to end. If the elongated bodies are to be rotated or axially positioned, the elongated bodies must be able to rotate freely with respect to the adjacent body or bodies they are connected to. When a long downhole tool is inserted within a deviated wellbore, forces of compression and tension result along the downhole tool because of the linear deformation of the tool caused by the curved wellbore. Free rotation of the elongated bodies of a downhole tool is hindered if the tool is under compression or tension. If free rotation of the elongated bodies is hindered, they will not be able to be positioned into the desired orientation. Therefore, when the downhole tool consists of multiple perforating guns, and compressive or tensile loading binds the guns, perforations cannot be produced at the desired spots along the wellbore.
Therefore, there exists a need for a device or system in connection with downhole tools containing orienting features, where the improvement provides flexibility and prevents binding of the tool when it encounters deviated or slanted wellbores.
One embodiment of the present invention discloses a system for use in a well comprising at least two downhole tools in combination with at least one swiveling sub. The swiveling sub connects the tools end to end. The swiveling subs incorporate two sections pivotally connected to each other on one of their ends, one possible form of connection involves a ball and socket configuration. Downhole tools, such as perforating guns, are connected to both ends of the swiveling sub.
Also included in the system is a wear ring positioned radially around each downhole tool. The wear ring outer diameter is greater than the outer diameter of said downhole tool and prevents the outer diameter of the downhole tool from contacting the inner wall of the wellbore. Because the downhole tool is not in contact with the inner wall of the wellbore, the downhole tool will not experience the type and magnitude of wear as seen by downhole tools that are allowed to rub along the wellbore inner wall. Further, preventing contact between the tool and the wellbore promotes free rotation of the downhole tool because the resistance to rotation due to the wellbore inner wall is removed. Bearings are included within the invention to promote rotation of the downhole tool with respect to the swiveling subs.
The present invention further includes a detonation cord axially disposed within each section. Each section also includes a shaped charge in cooperation with an explosive device that passes explosive detonation from its detonation cord to the detonation cord disposed in an adjacent section.
One of the many features of the present invention involves increasing the flexibility of a downhole tool string to facilitate ease of insertion and retraction of the downhole tool from a wellbore. Making the downhole tool string more flexible also decreases internal compressive and tensile stresses along the string which enables individual components of the tool string to rotate about their axis with respect to the remainder of the tool string.

Severe dog leg swivel for tubing conveyed perforating


A satellite antenna system (30) that employs a small phased antenna array (46) acting as redundant antenna. Because the phased array (46) is steerable, it can be selectively directed to any of the cells (16) on the Earth (12) in the event that the LNA in an antenna channel (32) fails. The phased array (46) is switched into each antenna channel (32) after the channel front end (40) where a switch (56) used to switch in the phased array (46) is after the amplification in the channel (32). Therefore, the switch (56) does not significantly affect the noise figure of the channel front end (32).

1. Field of the Invention
This invention relates generally to an antenna system providing redundant steerable beams and, more particularly, to an antenna system for a satellite that employs a small, phased antenna array that provides selectively steerable beams so that the redundant low noise amplifier in each antenna channel front end in the receiver of fixed antenna array can be eliminated and the antenna noise figure can be improved.
2. Discussion of the Related Art
Various communication systems, such as certain cellular telephone systems, cable television systems, intemet systems, military communication systems, etc., make use of satellites orbiting the Earth to transfer signals. A satellite uplink communications signal is transmitted to the satellite from one or more ground stations, and is then retransmitted by the satellite to another satellite or to the Earth as a downlink communications signal to cover a desirable reception area depending on the particular use. The uplink and downlink signals are typically transmitted at different frequencies. For example, the uplink communications signal may be transmitted at 30 GHz and the downlink communications signal may be transmitted at 20 GHz.
The satellite is equipped with an antenna system including a configuration of antenna feeds that receive the uplink signals and transmit the downlink signals to the Earth. Typically, the antenna system includes one or more arrays of feed horns and one or more antenna reflectors for collecting and directing the signals. Present antenna systems typically optimize the feed structure for the frequency band of interest and sacrifice other frequency bands. The uplink and downlink signals are typically circularly polarized so that the orientation of the reception antenna can be arbitrary relative to the incoming signal. To provide signal discrimination, one of the signals may be left hand circularly polarized (LHCP) and the other signal may be right hand circularly polarized (RHCP), where the signals rotate in opposite directions. Polarizers are employed in the antenna system to convert the circularly polarized signals to linearly polarized signals suitable for propagation through a waveguide with low signal losses, and vice versa.
FIG. 1 is an illustration of a spot beam satellite 10 orbiting the Earth 12. The satellite 10 includes an antenna system 14 that would include an array of antenna feeds, as would be well understood to those skilled in the art. Each feed is associated with a feed channel that may include separate transmitter and receiver architecture to transmit the downlink signal and receive the uplink signal. The satellite 10 may include multiple antenna arrays to increase or improve the coverage area on the Earth 12. Each feed in the antenna system 14 is configured to define a particular coverage cell 16 on the Earth 12. The feeds are directed to define contiguous cells 16, or provide a selected coverage area somewhere on the Earth 12. Each cell 16 would use signals in a particular sub-band within the uplink or downlink frequency band, or adjacent cells 16 would use different sub-bands at different points in time.
Each separate antenna feed channel includes a receiver front end providing signal amplification, typically by a low noise amplifier (LNA), and frequency down-conversion in a manner that is well understood to those skilled in the art. A failure of an LNA in the receiver front end would result in loss of an uplink signal. Because the LNA is a vital component for providing signal gain, and typically has an unacceptable failure rate, each antenna channel front end often employs a redundant LNA. Suitable switches are employed to switch the redundant LNA into the front end in the event that the main LNA fails. However, because the switch occurs in the front end prior to the signal amplification, the switch adversely adds to the noise figure of the receiver, and significantly affects the gain versus temperature noise (G/T) of the antenna system. Such an increase in the satellite G/T is an important design concern.
In accordance with the teachings of the present Invention, a satellite antenna system is disclosed that employs a small phased antenna array acting as a redundant steerable antenna. Because the phased array is steerable, it can be selectively directed to any of the cells on the Earth in the event that the LNA in an antenna channel fails. The phased array is switched into each antenna channel after the channel front end so that the switch used to switch in the phased array is after the amplification in the channel. Therefore, the phased array switch does not significantly affect the noise figure of the channel front end.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are intended for purposes of illustration only and are not intended to limited the scope of the invention.

Steerable uplink antenna for moveable redundant beams