A pressure-sensitive light-extracting drawing surface including a light guide operable to receive a light source, wherein light is extracted from a light guide when pressure is applied to the drawing surface by a marking instrument. A resultant light-emitting drawing can be erased or can be made permanent. An optional multi-layered film disposed on the light guide allows drawings to be created in fluorescent, luminescent, phosphorescent, or photochromic colors. A background sheet containing designs may be inserted behind the light guide. The drawing surface can be embodied as a pressure-sensitive light-extracting “paper.” The invention may be embodied as a drawing tablet, a drawing tablet add-on to a modular graphic display device, or a toy drawing tablet for tracing alphabets, numerals, and characters from comic books, cartoons, and movies.

1. Field of the Invention
The present invention relates to drawing and writing devices. More specifically, the invention relates to illuminated drawing surfaces, tablets, and boards.
2. Description of Prior Art
Drawing and writing tablets and boards have existed for generations. Examples include chalk boards, white boards, mechanically-aided drawing devices, clipboards with side or back illumination, magnetic drawing tablets, fluorescent ink pens, luminescent tablets, phosphorescent tablets, thermochromic tablets, and pressure-sensitive tablets using plastic film and wax. There are several patents that discuss such tablets and boards for drawing and writing.
U.S. Pat. No. 3,279,100 issued to Knott and titled "Exhibitor of Informative Markings Removably Applied by Pressure to a Display Surface Thereof", discloses a pressure-sensitive drawing tablet using multiple layers of wax and plastic which allows displays in color by shifting a backing surface printed with a grid of red, yellow, and blue squares.
U.S. Pat. No. 3,579,871 issued to Eddington and titled "Record book", discloses in the Abstract: "A record book comprising a plurality of leaves wherein each leaf is centrally divided in the transverse direction with separate writing sections located on each side of the division. Each writing section includes a series of longitudinal separate writing spaces, each space having a wax backing with an opaque writing strip covering the backing and a clear plastic outside cover over the writing strip. The writing strip of each space can be removed from in contact with the wax backing. The stylus is to be retained when not in use within a hinge connection which maintains the entire book in the closed, not-in-use position." This record book uses multiple layers of wax and plastic allowing different sections of writing to be separately erased. This record book is not illuminated.
U.S. Pat. No. 4,051,609 issued to Boursaw and titled "Method of Making Reusable Writing Board and the Product Thereof", discloses in the Abstract: "A reusable writing board of 'slate board' is both improved and of lower cost, avoiding use of the usual separate black-cardboard piece stapled to a backing. In a single printing operation, which is needed for face-printing anyway, the 'slate' or background surface is provided on the same piece of paperboard. After further machine steps, a final operation of gluing and folding produces the finished slate board with a decoratively-printed head panel glued to extend down protectively over the top edge of the plastic work sheet covering the printed background. If desired, educational or informative discs can be rotatably secured under the head fold. Also, if desired, an air pocket can be formed under the head fold such that after writing by impressions through the work sheet, a sudden slap on the cover of the air pocket will raise the work sheet pneumatically to erase the writing." This method describes an improved manufacturing process for producing a reusable writing board using multiple layers of wax and plastic allowing erasure with a slap on the cover of the board. The writing board, however, is not illuminated.
U.S. Pat. No. 4,590,381 issued to Mendelson and titled "Phosphorescent Marking System", discloses in the Abstract: "A device of phosphorescent material on which luminescent images are formed and retained for a period of time is disclosed. The device includes phosphorescent material in the form of a sheet mounted on a support. The support exposes the top surface of the phosphorescent material to activating light. A shield maintains deactivation of the phosphorescent material. Upon removal of the shield in a dark area, the phosphorescent material may be activated in selected areas to form an image which is retained for a period of time until the phosphorescent material has decayed to an inactivated state of imperceptible level of luminescence. This type of device is particularly suited to amusement and educational items for children. However, it is also useful in industrial applications where writing and communication of information in the dark is necessary." The marking system describes using a light pen to form an image on a sheet of phosphorescent material. A shield that blocks light of the activating wavelength of the phosphorescent material is placed above the sheet to ensure that the sheet remains in a deactivated state, or, in the event that the sheet has been activated, that the deactivation of the phosphors proceeds unperturbed. The system can only be used in a dark area, requires a light pen, and involves constant covering and uncovering of the phosphorescent sheet.
U.S. Pat. No. 4,888,874 issued to Oster and titled "Drawing Device Having Mobile Stylus Tracing Lines on Glass Plate", discloses in the Abstract: "A toy drawing device in which a window in a housing containing powder is covered by a glass plate whose edges are received within a groove in a sectioned rim joined to a window frame to prevent leakage of powder therefrom. A mobile stylus under the control of an operator acts to trace lines on a layer of powder adhering to the undersurface of the glass plate. To prevent injuries should the glass plate break, its outer surface is shielded by a transparent protective film formed of heat-formable, synthetic plastic material." A mechanically-controlled stylus is used to trace lines on the underside of a glass screen to which a powdered substance adheres. The glass screen is shielded by a transparent protective film to prevent injury due to a break in the glass. The device, however, is not illuminated, is bulky and heavy, and is expense to manufacture.
U.S. Pat. No. 4,927,748 issued to Kinberg and titled "Luminescent Writing or Display Device", discloses in the Abstract: "A display or writing slate capable of producing luminescent images upon the application of pressure thereon which can be readily erased and repeatedly used that includes a pair of over-lying sheets, one of which is translucent or transparent, containing a luminescent dye or pigment and the other of which is opaque, and which sheets have a smooth surface at their interface. At least one of the sheets is formed of a pliable plastic with its interface surface tending to adhere to the interfacing surface of the other sheet when a pressure is applied thereto to produce the luminescent images. The improvement resides in the incorporation of a non-migrating dye or pigment in the translucent or transparent sheet so as to resist the migration of the luminescent dye or pigment from the translucent or transparent sheet to the interface surface of the other sheet." This patent describes a writing device where pressure from a stylus onto a translucent sheet containing a luminescent dye produces a luminescent image. While the device displays an image through luminescence, the device does not allow for enhanced color, brightness, and contrast.
Japanese Pat. 03248151A issued to Takeshi et al. and titled "Method for Writing and Erasing Using Photochromic Board and Photochromic Board for the Purpose", discloses in the Abstract: "To allow writing and erasing to and from a photochromic board from a distant position by irradiating the photochromic board with a beam for a 1st wavelength to allow the photochromic material to develop a color and to write characters, etc., and casting hot air or light of a 2nd wavelength to the color developed part to erase the written characters, etc." The writing surface of the board contains a photochromic compound and the writing instrument is a wand that emits light of activating and deactivating wavelengths of the photochromic compound. The device uses a beam of light from a wand to create characters in photochromic color, but does not allow for enhanced color, brightness, and contrast.
U.S. Pat. No. 5,083,242 issued to Piotrowski and titled "Illuminated Underwater Writing Tablet", discloses in the Abstract: "An illuminated underwater writing tablet having an elongated tubular lightsource housing and an elongated tablet sheet of Plexiglass material. The lightsource housing has an elongated slot in its bottom surface that receives the top edge of the tablet sheet. A chemically activated light stick is removably stored in the light source housing and when it is activated it will illuminate the tablet sheet by directing light through its interior. A grease stick is tethered to one end of the lightsource housing. An end cap is tethered to the other end of the lightsource housing." This writing tablet describes a plastic tablet sheet, a tubular light source housing, a chemically activated lightstick stored in the housing, and a grease pen. The writing tablet displays an image through a chemically activated lightstick.
U.S. Pat. No. 5,321,891 issued to Arad et al. and titled "Drawing Device", discloses in the Abstract: "This invention relates to an apparatus for writing or drawing that is characterized by an enclosed case having a front side and a back side and in which the front side consists of a transparent screen. Disposed within a substantially rectangular case is a slightly adhesive powder which adheres to the undersurface of the transparent screen so as to render it opaque. A first and second stylus is mounted within the case for producing relatively thick and relatively thin lines by movement along the undersurface of the transparent screen in a manner for removing the adhesive powder and to thus produce lines. The first and second stylus are both moved in the X and Y coordinates through the use of external horizontal and vertical line control knobs which are internally coupled to the multiple stylus by first and second transverse rods, each being supported on and attached to a separate cable loop system. The multiple stylus may be fixedly withdrawn from the screen by actuation of the retraction thus enabling the operator to use both hands for moving the stylus to a second horizontal and/or vertical position on the screen without production of a line from the first to the second writing or drawing." Two mechanically-controlled styluses are used to trace thick and thin lines on the underside of a transparent screen to which a powdered substance adheres. The powder lines can be erased by gently shaking the drawing device. The device is not illuminated, and is bulky, heavy, and expense to manufacture.
U.S. Pat. No. 5,324,202 issued to Meyers et al. and titled "Luminescent Display and Copying Apparatus and Method for Using Same", discloses in the Abstract: "An apparatus and method for providing a luminescent display by applying pressure to a transparent planar sheet containing a luminescent dye or pigment where such pressure is sufficient to cause one smooth surface of the transparent sheet to contact a facing smooth surface of an opaque planar sheet, the smooth surfaces of the transparent and opaque sheets tending to adhere together at the area of contact, thereby creating a luminescent image at the area of contact which can be selectively erased by separating the smooth surfaces of the transparent and opaque sheets at the area of contact, and for allowing copying of the image by positioning a sheet of carbon paper between the opaque sheet and a sheet of plain paper so that the application of pressure to the transparent sheet causes pressure to be applied through the carbon paper to the sheet of plain paper, thereby copying the image displayed on the transparent sheet onto the sheet of plain paper, the carbon paper being selectively movable to allow segments of carbon paper which can produce images of different colors to be positioned between the opaque sheet and the sheet of plain paper during the drawing of an image to facilitate the production of a multi-colored copy of the displayed image, the apparatus allowing the use of different sizes and multiple sheets of plain paper and providing means for ejecting such paper from the apparatus." The apparatus displays an image through luminescence only, and does not allow for enhanced color, brightness, and contrast.
U.S. Pat. No. 5,368,489 issued to Confalone et al. and titled "Luminescent Display Device", discloses in the Abstract: "A luminescent writing or display device and method of manufacturing the same which includes a transparent vinyl sheet containing a fluorescent or neon dye and an opaque sheet made from coated paperboard stock. An acrylic resin varnish is provided on a portion of the paperboard stock for forming a contact surface with the vinyl on which an image may be created by applying pressure thereto. The image is readily erased by separating the sheets. Another portion of the paperboard stock receives printing inks for providing a permanent ink display on a header portion of the device. The device may be manufactured in a continuous process at a reduced cost." The device displays an image through luminescence only, but does not allow for enhanced color, brightness, and contrast.
U.S. Pat. No. 5,441,418 issued to Brown and titled "Thermochromic Drawing Device", discloses in the Abstract: "A thermochromic drawing device is disclosed which can be marked and erased by selectively changing the temperature of its drawing surface. The drawing surface of the drawing device consists of a flexible substrate printed with thermochromic inks having at least two color states. The flexible substrate has low thermal mass thereby enabling it to readily assimilate temperatures induced by a user and, consequently, facilitating the transition of the thermochromic inks from one color state to another. The drawing surface is further provided with an insulating layer which isolates the flexible substrate from unwanted heat sinks and heat sources thereby preventing unwanted color transitions of the thermochromic inks. Thus, a user can selectively change the color state of portions of the drawing surface to create distinctive markings." The device comprises of a substrate coated with thermochromic inks, a heat insulating layer underneath the substrate, and a pen containing a cooling substance and a heat conducting tip. The cool tip of the pen in contact with the thermochromic substrate creates the drawing, which can be erased by the user placing his hand over the drawing. The device displays an image through thermochromic inks only, and does not allow for enhanced color, brightness, and contrast through illumination.
Japanese Pat. 07314981A issued to Kazuo and titled "Display Board and Writing Instrument for Display Board", discloses in the Abstract: "To erase a part to be deleted in a single tracing pass by making the light projection width of a deletion pen larger than the light projection width of a writing pen, using a writing sheet of a photochromic material." A photochromic writing tablet is used with a writing pen and a deletion pen. The writing pen emits a UV light that activates the photochromic material, whereas the deletion pen emits white light that erases the photochromic writing. The tip of the deletion pen is wider than the tip of the writing pen, thereby allowing the deletion pen to erase a line of writing with one stroke. The device uses a light-emitting pen of activating wavelength to create characters in photochromic color only.
U.S. Pat. No. 5,607,223 issued to Brotz and titled "Illuminated Clipboard with Movable Writing Surface", discloses in the Abstract: "An illuminated clipboard for use by a seated individual in dark surroundings with structure to attach the clipboard to a leg of the user, such clipboard having a light-emitting body in one embodiment with means to illuminate therethrough utilizing a sheet of illuminated material disposed thereunder and a translucent roll of film or paper on a spool which is passed from a storage roller to a take-up roller over the active writing surface of the light-emitting planar surface in immediate contact therewith such that indicia or writing thereon is visible to the user by backlighting from the underlying illuminated planar body." A clipboard with a contoured back is attached to a leg of the user for writing using a pencil or pen on a translucent sheet. The sheet is illuminated by a backlighting panel, but is not erasable.
U.S. Pat. No. 5,938,449 issued to Masson and titled "Reusable Writing Board with Locking Function", discloses in the Abstract: "A pressure sensitive reusable writing board is provided which includes a backing member that includes an upper section that folds down over the lower section that accommodates the wax layer and polyester writing sheet. As a result, the upper section provides a protective cover for the lower section. A distal edge of one of the upper or lower sections includes a loop which is in registry with a slot disposed in the distal edge of the other of the upper or lower sections. As a result, when the board is folded together to assume a closed position, the loop may be folded forward through the slot disposed in the opposing section or panel and the stylus may be inserted through the loop to lock the board into a closed position. As a result, any writing or artwork made on the reusable writing surface can be preserved while the board is being transported or handled." The writing surface consists of a wax layer covered with a polyester film. Pressure from a stylus on the polyester film creates a drawing that is not illuminated.
U.S. Pat. No. 6,092,294 issued to Mak and titled "Drawing Board", discloses in the Abstract: "A drawing board having a body and a generally transparent screen on the body. The screen has front and rear sides and contains a viscous opaque liquid and iron dust in the liquid. A magnetic eraser is movable within the body between a rest position away from the rear side of the screen and an operating position against that rear side for operation to move, through magnetic attraction, the iron dust away from the front side of the screen such that the iron dust becomes invisible on the screen. A spring biasses the eraser towards the rest position. A pen having a magnetic tip is used to draw on the screen." The drawing board is not illuminated and requires a magnetically tipped pen.
U.S. Pat. No. 6,113,150 issued to Kinberg and titled "Luminescent Writing Display Device Having Protective Layer", discloses in the Abstract: "A writing and display device for producing luminescent images upon application of pressure thereon which can be readily erased and repeatedly used having a protective layer to prevent damage to the writing surface thereof. The device includes a backing member with a smooth surface over which a translucent or transparent sheet containing a luminescent dye or pigment and an opaque pliable plastic sheet are disposed. At least one of the sheets is formed of a pliable plastic with its interface surface tending to adhere to the interfacing surface of the other sheet when a pressure is applied thereto to produce luminescent images. A pliable, transparent protective sheet is disposed adjacent to and coextensive with the translucent or transparent luminescent sheet. Upon application of pressure onto the protective sheet, which pressure is transmitted to the luminescent sheet by virtue of the pliability of the protective sheet, the interfacing surfaces adhere to each other to thereby produce a luminescent image." This patent describes a pressure-sensitive luminescent sheet. A pliable transparent sheet is placed above the luminescent sheet to prevent puncture and damage to the luminescent sheet from the stylus. Compared to the present invention, this device displays an image through luminescence only on a pressure-sensitive sheet, and does not allow for enhanced color, brightness, and contrast.
U.S. Pat. No. 6,578,615 issued to Bronson and titled "Magic Slate Capture and Display Device", discloses in the Abstract: "A device for forming erasable images on a reusable medium, comprising: an erasing portion; and a writing portion; wherein the erasing portion comprises a separator for separating at least two layers of the reusable medium; and wherein the writing portion comprises automatic machine-driven pressure applicators for applying pressure but no ink to the reusable medium, thereby forming an image on the reusable medium." The display device is not illuminated and is intended primarily for use as a computer-controlled printer.
U.S. Pat. Application 2003/0112623 by Yu Sun et al. and titled "Ultraviolet Light Writing System", discloses in the Abstract: "An ultraviolet light emitting diode flashlight is contained within a housing having a pen tip extending from the housing and an ink or dye reservoir in fluid communication with the pen tip. The ultraviolet light emitting diode flashlight within the housing emits light capable of inducing fluorescence in the ink or dye. A switch assembly completes an electrical circuit between a light emitting diode and a battery to activate the flashlight. A writing system package includes at least two of: a neon or pastel colored writing surface, a security pen having an ink or dye that fluoresces in the visible portion of the light spectrum upon exposure to ultraviolet light, and an ultraviolet light emitting diode flashlight." The system allows visualization of writing in invisible ink during writing, but requires a special fluorescent ink, and the writing is not erasable.
Japanese Pat. 2003222971 issued to Hiroyuki et al. and titled "Method for Displaying Multicolor Image, and Multicolor Image Display", discloses in the Abstract: "To provide a method for displaying a multicolor image and a multicolor image display excellent in resistance to repeated image writing and erasure with light and having good colors of an image" The multicolor image display device uses photochromic compounds as the display media and LED arrays of different activating and deactivating wavelengths. Arrays of LEDs activate and deactivate the photochromic compounds, but the device does not allow for enhanced color, brightness, and contrast.
U.S. Pat. No. 6,666,742 issued to Koizumi and titled "Controlling Light Discharged by a phosphorescent Material", discloses in the Abstract: "A material that phosphoresces may be controlled and the phosphorescence may be terminated when desired. A phosphorescing material may be exposed to an energy source that causes the material to stop phosphorescing. Thus, a pattern may be written on a surface, which is phosphorescing using a coherent energy source. The written pattern, represented by darkened regions, may be recognized by users as a symbol, a graphics or text." The device displays an image on a phosphorescent background, but does not allow for enhanced color, brightness, and contrast.
U.S. Pat. No. 6,722,891 issued to Ma and titled "Magnetic Drawing Board Apparatus"(Ma Apr. 20, 2004) discloses, in the Abstract: "A magnetic drawing apparatus including image forming means, image erasing means, motion generating means, movement control means and a main housing, wherein: the image forming means include a plurality of magnetic cells which collectively define an image forming surface, the magnetic cell contains a viscous fluid and magnetic powder; the image erasing means include a magnetic image eraser which is adjacent to the image forming means, the magnetic image eraser is connected to the motion generating means and is movable relative to the image forming means; and the movement control means include means for actuating the motion generating means and means for selecting the direction of movement of the magnetic image eraser with respect to the image forming means." The drawing board is useful and interesting for children, but the board is not illuminated.
What is needed, therefore, is a drawing and writing paper that overcomes the above-mentioned limitations of the prior art and that: (1) provides bright light-emitting drawings and writings, (2) provides easy-to-read drawings and writings in single or multiple colors, (3) uses a stylus or equivalent pressure-applying device as the marking instrument, (4) is erasable or permanent, (5) is easy to operate, (6) allows for easy insertion of background colors and designs, (7) can be used under day or night lighting conditions, (8) is multipurpose (e.g. toy, bulletin board or white board, used in the dark, under water, in harsh environments), (9) is waterproof, (10) is thin and lightweight in construction, (11) is inexpensive to manufacture.


A prefabricated house is provided which includes wall and corner support posts erected on a foundation, which posts are connected in their upper portions by frame members and carry wall elements. Each of the posts are formed of an inner and an outer stud which are clamped together with a fishplate mounted at the foundation, in such a manner as to also clamp the vertical edges of the wall elements supported thereby.

The invention relates to a prefabricated house of the type with posts erected on a foundation (wall posts and corner posts) connected by frames at their upper ends, as well as with wall elements inserted between the wall posts and corner posts, respectively.
The term "prefabricated house" is understood to mean, within the scope of this invention, buildings, the structural elements of which are prefabricated more or less extensively as a construction module and are merely assembled at the building site. In this arrangement, posts and frames constitute a load-bearing supporting structure in which the wall elements are inserted. In conventional prefabricated houses, the technique of concrete construction is the basis employed, i.e. posts and frames as well as essentially the wall elements are manufactured in the form of concrete or reinforced concrete parts, assembled at the site, and jointed with cement, mortar, or the like.
The above-described, customary mode of operation cannot be readily applied to building with wood. In wood construction, the blockhouse design is known, in essence, with timbers in horizontal superposition and the framework construction technique is primarily employed wherein the areas formed by posts and frames are filled out in various ways. Both aforementioned wood construction methods do not represent, strictly speaking, any prefabrication and moreover exhibit various disadvantages making their use impractical in modern wood construction. Both building methods are exraordinarily expensive in labor and material. Besides, in the block-type mode of construction, it is very difficult to attain a satisfactory seal and insulation. In the framework construction method, considerable static problems occur which can only be controlled by the voluminous use of trusses, tie beams, struts, diagonal reinforcements, etc., entailing considerable expenditure.
The invention is based on the problem of providing a prefabricated house of the type described in the foregoing which, with maximally complete prefabrication, can be erected economically, is distinguished by high stability, satisfies all requirements with respect to insulation and sealing features, and, in particular, makes it possible to meet these demands even in the wooden construction.
This problem is solved, according to particularly preferred embodiments of the invention by providing that each post consists of a baseplate, which latter can be connected to the foundation and can be leveled, this baseplate having at least one vertical fishplate attached thereto, as well as at least one inner stud and one outer stud, wherein the inner and outer studs are attached to the fishplate and each wall element is clamped in place along its vertical sides between respectively one inner stud and one outer stud.
Thus, according to the invention, the joining of the wall elements to one another and to the posts is attained by fashioning the posts in pairs and by clamping the wall elements between the outer and inner studs constituting the posts. Neighboring wall elements are, of course, clamped between outer and inner studs which are the same in pairs for both wall elements. This leads to a seal at the butt joints of neighboring wall elements, which seal is flawless under all circumstances; the wall elements proper can be readily designed so that they satisfy the requirements with respect to insulation and sealing.
While in the prefabricated house according to this invention, the connection to the foundation is ensured by the baseplates and fishplates, the entire construction is provided with an extraordinarily high static stability due to the feature of clamping the wall elements in place at the posts. In this connection, an aspect which is of high importance is that the wall elements--as contrasted to the area-filling character in the customary framework construction--themselves contribute toward the stability of the entire construction, due to their positive clamping engagement at the posts. A prefabricated house according to this invention can be most extensively built beforehand as a structural module and can be assembled at the site in a simple manner. It is of special importance herein that it is readily possible to design the structure as a wooden building, i.e. especially to make the posts and more or less extensively also the wall elements of wood; and that the techniques customary in wooden construction can be utilized during assembly. Basically, a prefabricated house according to this invention can be made of one floor as well as several floors, but primarily the mode of construction according to this invention is applicable to single-family homes with one to one-and-one-half floors.
The invention as described above relates, in particular, to the construction of the wall structure and its connection to the foundation. The structure and connection of the roof construction can be effected in the usual, conventional way and thus need no further explanation. The posts are extended, for this purpose, upwardly to the roof construction (for example up to the central roof beam or base joist).
The baseplate of each post preferably consists of a steel plate to which the fishplate is welded. The fishplate can consist of a simple flat steel plate or--considering the provision of greater ruggedness--it can have a cross-shaped cross section in such a way that mutually opposed cross legs point in the direction of the outer or inner stud and engage corresponding grooves of these studs. A connection of the baseplates to the foundation permitting a leveling step can be attained by providing each baseplate with three passage bores arranged at the corners of a triangle and encompassing respectively one stay bolt attached in the foundation and equipped with a thread; by means of nuts, the baseplate can be adjusted in height, leveled, and fixed in position with respect to the stay bolt. After the leveling step, cement is poured under the baseplate.
At the wall posts where two wall elements abut planar, the baseplates are preferably arranged so that the connecting line of two passage bores extends in the direction of the wall whereas, at corner posts, where wall elements abut with the formation of a corner, the two connecting lines of the passage bores extend in the direction of the abutting walls. The contour of the baseplate is preferably triangular in correspondence with the arrangement of the passage bores.
The outer and inner studs of each post have mutually facing, parallel, planar clamping surfaces, by means of which they contact the fishplate and/or the wall elements to be clamped in place, so that a firm composite structure results in the zone of each post. The following description is based on the assumption that the inner studs directly contact the fishplate and that the outer studs are braced against the fishplate and the inner stud with the inclusion of the wall elements. Alternative embodiments are contemplated with a reverse arrangement.
With a view toward a simple assembly, it is advantageous to provide that the inner stud and the outer stud can be braced (tensioned) independently of each other by means of screw bolts with the fishplate. This can be realized, for example, by making the inner stud and the outer stud braceable by means of common threaded bolts which penetrate the fishplate and are connected nonrotatably and non-displaceably with the fishplate, for example by welding. It is also contemplated to provide respectively separate threaded bolts for the inner and outer studs; in this connection, it is possible, especially by a countersunk arrangement and/or a suitable selection of the bolt heads, to make the threaded bolts releasable from the outside. In addition to the threaded bolts arranged in the zone of the fishplate, it is contemplated in certain embodiments to directly brace the outer and inner studs together by means of additional threaded bolts distributed along their lengths, to obtain an even stronger composite connection with the wall elements.
At least in the zone of the fishplate, it is advantageous to provide the inner or outer stud in contact with this fishplate with a groove on the side facing the fishplate, the latter engaging this groove in a flush manner so that a flat contact of the wall elements at the stud is ensured.
The frames interconnecting the posts in the upper zone are provided, according to a further teaching of this invention, in pairs and consist of respectively one inner frame and one outer frame joined to the inner studs or to the outer studs from the inside and from the outside, respectively. In other words either the inner studs or the outer studs, preferably the inner studs, are clamped in place between the frames arranged in pairs, which is preferably accomplished by means of threaded bolts. In this arrangement, the outer studs terminate underneath the outer frames whereas the inner studs--as explained above--extend all the way up to the roof structure. A ceiling construction is erected on the frames in the usual way with beams, panels, etc. laid on top thereof. In the areas remaining between the frames, the beams, and the ceiling construction, headers (bridging members) are inserted which--just as the wall elements described hereinbelow--are of a framework construction and can optionally also be fashioned as a skylight. The headers are preferably braced at the frames along their bottom sides, fixed in place along their topsides by the correspondingly constructed roof structure, and sealed with respect to the beams along the sides by sealing inserts, tongue-and-groove joints, or the like.
The wall elements are preferably fashioned in frame construction filled by a paneling constructed in correspondence with the respective requirements regarding thermal and sound insulation, weatherability, etc. and being made up of multiple layers as a rule. Within the filling, reinforcements for the frame construction can, of course, be extended. The wall elements are clamped along the sides--as explained above--between outer and inner studs of the posts. It is furthermore advantageous to dimension the wall elements with respect to their height so that they extend in between the inner and outer frames and consequently are also clamped in position along their topsides. This achieves the required sealing effect and simultaneously further improves the static stability due to the force-derived connection to the frames. On the underside, the wall elements can be sealed with respect to the foundation by plaster flooring which simultaneously exerts a supporting function. It is advantageous to attach to the underside of the wall elements a covering strip placed in front of the flooring, improving the external appearance of the house and furthermore facilitating the production of the flooring. It is finally recommended to take care, by a suitable dimensioning of the wall elements, that a gap exists between neighboring wall elements, closed off by the inner and outer studs, ensuring venting or aeration advantageous for the wooden building elements.
The inner walls, in an embodiment which is to be preferred, consist of room divider elements shape-matingly inserted between the posts (without force-derived clamping action), which room divider elements are grooved along the narrow sides, whereas strips adapted to the grooves are provided at the inner studs along the inner sides facing the room divider elements. The room divider elements preferably likewise consist of a frame construction equipped in the usual way with a filling material meeting the requirements regarding sound and heat insulation etc. The strips provided for the shape-mating connection between the inner stud and the room divider elements, which strips are preferably made of hardwood, can advantageously be attached to the insides of the inner studs and secured by a tongue-and-groove joint. The installation of the room divider elements takes place during the course of erecting the house in such a way that the room divider elements are inserted, prior to constructing the ceilings, from above between the posts. The joints between the room divider elements and the neighboring inner studs, in certain cases also between the ceiling and the floor, can be sealed by sealing inserts or by the subsequent introduction of a sealing compound.
An advantage attained by the pairwise arrangement of the frames with inner and outer frame members resides in that it is made possible to insert blinds, which may be provided, above the wall elements--provided with windows--in the interstice between the inner and outer frames. The blind can be passed through and guided, for example, by providing on the outside of the wall elements a recess open at the topside (the cross section of this recess corresponding essentially to the cross section of the blind) and by arranging guide means for the blind along the lateral boundaries. In the zone of the recess, the clamping and sealing of the topside of the wall elements with respect to the outer frames are, of course, omitted. In general, but especially in the zone of such blind recesses, it is thus recommended to insert cover plates for sealing purposes on the inside between the wall element and the inner frame. Such cover plates can furthermore also be arranged between the blinds inserted above the wall elements and the inner frame. In any event there is the possibility of fashioning the cover plates as fill-in wood elements of corresponding buckling strength and use same at the same time as an abutment for the clamping of wall elements and/or blinds between the inner and outer frames.
The above-description has addressed itself essentially to the wall posts arranged along the course of a linearly extending wall. In the zone of the house corners, special measures are provided. Here, the invention teaches, first of all, to equip the corner posts with respectively one baseplate with two fishplates arranged in mutual inclination in accordance with the corner angle. Basically, a corner can be formed by associating with the two abutting wall elements respectively one outer stud and one inner stud. However, the corners can also be closed in an especially simple way by the feature that the corner posts have respectively one single inner stud which, so to speak, represents a corner pillar, and can be braced together with both fishplates of the baseplate, wherein the threaded bolts of at least one fishplate are detachable. The detaching of at least one of the threaded bolts is necessary to place the inner stud into the angle formed by the fishplates. If the fishplates (as explained above) are of the shape of a cross in cross section and/or engage in grooves of the inner stud, it is necessary to remove the threaded bolts of both fishplates, to lower the inner stud from above in between the fishplates, and only thereafter to insert the threaded bolts.
For clamping the wall elements in position at the inner stud constituting the corner, various possibilities can be employed according to the invention. Thus, an angular molding, the angle legs of which have a thickness corresponding to the wall elements, can be placed in front of the outer edge of the inner stud, both outer studs extending over this angular molding. The angle legs form abutments for the outer studs which are placed in front thereof for bracing purposes. The surface on the outside of the angular molding corresponds here, for design reasons, preferably to the surface of the wall elements. Another possibility resides in placing, in front of each of the wall elements braced against a corner stud, an outer stud having an angular cross section, one leg of this stud resting against the inner stud. This supporting leg absorbs the clamping stress and has a length on the inside of the profile which corresponds to the thickness of the wall element.
The advantages attained by this invention reside essentially in that a prefabricated house construction is provided which can be made of wood economically and without difficulties; provides high stability as well as optimum insulation and sealing features; and permits extensive prefabrication. With respect to design viewpoints, it is of special importance that all structure-forming elements (studs, frames, etc.) are clearly visible and convey an unobstructed, functional outward appearance. This holds true--with a desirable, rustic slant--especially in the wooden type of construction contemplated primarily in this invention, wherein the frame, the studs, the framework constructions of wall elements and room divider elements etc. are made of wood, preferably of glued-together wood.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.


A method for surface treatment of acrylate-based superabsorbents may include preparing a treatment solution including water, an organic solvent, and a silane compound; applying the treatment solution to a plurality of acrylate-based superabsorbents to form a mixture; and fabricating modified acrylate-based superabsorbents by subjecting the mixture to heating or microwave irradiation.

Superabsorbent polymers (SAPs) are generally capable of absorbing and retaining amounts of aqueous fluids equivalent to many times their own weight. After absorption of an aqueous solution, swollen SAP particles become very soft and they may be deformed easily. Upon deformation, the void spaces between the SAP particles may be blocked which may increase the flow resistance for liquids. This is generally referred as "gel-blocking".
SAP particles may include a partially neutralized lightly cross-linked polyacrylic acid network, which is a hydrophilic network and permits swelling of the network once submerged in water or any aqueous solutions. The cross links between the polymeric chains may assure that the SAPs do not dissolve in water. SAPs applied in form of small particles, such as fibers or granules.
One way to reduce gel-blocking is to make the SAP particles stiffer, which enables the SAP particles to retain their original shape thus creating or maintaining void spaces between the particles.
Low swollen gel strength and the adverse effects of gel-blocking are two major challenges of the superabsorbents. Therefore, there is a need in the art to provide SAP particles with a high degree of surface cross-linking in order to avoid gel-blocking and to have a high swollen gel strength.


This invention relates to a bleed valve of a compressor, in particular a compressor of a bypass aero-engine, with a guiding device provided downstream of a valve body in the bleed duct, said guiding device directing the bleed airflow from a compressor duct to a bypass duct in such a manner that the direction of the flow of the bleed airflow is imparted with a component which is unidirectional with the airflow carried in the bypass duct. The present invention provides a dissipation screen in the bleed duct between the valve body and the guiding device to reduce the energy contained in the bleed airflow, thereby decreasing the loading of the bypass duct. Moreover, the present invention provides for an attenuation chamber downstream of the dissipation screen as viewed in the direction of the bleed airflow. In a preferential arrangement, the guiding device is a plate which is essentially parallel to the wall of the bypass duct and which contains a plurality of bores inclined in the direction of flow of the airflow carried in the bypass duct.

This invention relates to a bleed valve of a compressor, in particular a compressor of a bypass aero-engine, with a guiding device provided downstream of a valve body in the bleed duct, said guiding device directing the bleed airflow from a compressor duct into a bypass duct in such a manner that the direction of flow of the bleed airflow is imparted a component which is unidirectional with the airflow carried in the bypass duct. For background art, reference is made to Specification U.S. Pat. No. 4,463,552, by way of example.
It is generally known that compressors, in particular those for gases, are provided with bleed valves to preclude the compressor from exceeding its surge limits, i.e. some of the gas flow or airflow compressed in the compressor is bled, if necessary, from the compressor without passing all stages of the multi-stage and in particular the multi-stage axial-flow compressor. In the case of bypass aero-engines, the so-called bleed airflow of the compressor is introduced into the bypass duct which carries the airflow supplied by the engine fan.
The known, simple bleed valves are provided with discharge ducts which introduce the bleed airflow into the bypass duct essentially vertically to the bypass airflow carried therein. In these designs, the outlet ports of these discharge ducts are vertical to the wall of the bypass duct. Since the bleed airflow can be very hot, failure of the bleed valve or its control is liable to cause damage to the bypass duct or its wall, respectively, in particular if the bleed valve is open for a longer period of time. The hot supersonic flow bled from the compressor will then have a detrimental effect on the structure of the bypass duct and the components adjacent to it.
The bleed valve taught in Specification U.S. Pat. No. 4,463,552 mentioned in the beginning reduces this detrimental effect by way of a guiding device which introduces the bleed airflow to the bypass duct in at least partly the direction of flow of the airflow carried therein; however, in a broad aspect, the present invention provides further, beneficial features to remedy the above problematics.
It is a particular object of this invention to provide a so-called dissipation screen in the bleed duct between the valve body and the guiding device. Further aspects and advantages of the present invention are cited in the subclaims.
Besides the guiding device, the present invention provides a dissipation screen which reduces some of the kinetic energy, i.e. some of the impulse of the bleed airflow. Upon being released via the opened valve body, the bleed airflow passes this essentially narrow-meshed dissipation screen (or dissipation grid or the like) provided in the bleed duct of the bleed valve and, via the guiding device, enters the bypass duct in the desired direction of flow. The swirling and intensive throttling action at the so-called dissipation screen reduces the impulse of the bleed airflow introduced to the bypass duct to such an extent that it will produce virtually no detrimental effect on the bypass duct. In addition, the dilution between the airflow carried in the bypass duct and the bleed airflow introduced to it will thus be improved, a generally desirable effect.
With regard to the operation of the guiding device, the provision of a so-called attenuation chamber between the guiding device and the dissipation grid can be beneficial to partly reduce the swirl effected at the dissipation screen (or grid). A guiding device which is particularly favorable since it includes the function of a screen (or grid) is explained in claim 3, according to which the guiding device is designed as a plate which is essentially parallel to the wall of the bypass duct, this plate being provided with a plurality of bores whose axes are inclined in the direction of flow of the airflow carried in the bypass duct. Here, optimum results are obtained when the surface of the guiding device is essentially twice the surface of the dissipation screen since, then, the additional throttling effect at the dissipation screen will not impair the throughput potential of the bleed valve.
Further objects and advantages of this invention will become apparent from the following detailed description of a preferred embodiment read in the light of the accompanying FIG. 1 which illustrates a cross-section of a compressor bleed valve in accordance with the present invention in the installed state (between a compressor annulus and a bypass duct), with reference being made to FIG. 2 which shows the View X of FIG. 1. In this context, all features described in detail can be essential for the invention.

Bleed valve of a compressor, in particular a compressor of a bypass aero-engine


An arrangement for implementing a network in an ISDN-BASED customer premises having a 4-wire ISDN S0 bus. The ISDN-BASED customer premises includes a Network Termination Basic Access (NTBA) that interfaces between the residential customer premises and the public switched telephone network by mapping the 2-wire ISDN signal onto the 4-wire bus. A low pass filter is added to the 2-wire send path to eliminate high frequency noise caused by harmonic reflections of the ISDN-based signals on the 4-wire bus. The filter also provides a delay between the zero crossing of the ISDN-based signals and the transmitted network signals, minimizing the effect of the ISDN zero crossings on the home network signal.

The present invention relates to network interfacing, and more particularly, to methods and systems for controlling transmission of data between network stations connected to a telephone line medium.
Local area networks use a network cable or other media to link stations on the network. Each local area network architecture uses a media access control (MAC) enabling network interface cards at each station to share access to the media.
Conventional local area network architectures use media access controllers operating according to half-duplex or full duplex Ethernet (ANSI/IEEE standard 802.3) Protocol using a prescribed network medium, such as 10 BASE-T. Newer operating systems require that a network station to be able to detect the presence of the network. In an Ethernet 10 BASE-T environment, the network is detected by the transmission of a link pulse by the physical layer (PHY) transceiver. The periodic link pulse on the 10 BASE-T media is detected by a PHY receiver, which determines the presence of another network station transmitting on the network medium based as detection of the periodic link pulses. Hence, a PHY transceiver at Station A is able to detect the presence of Station B, without the transmission or reception of data packets, by the reception of link pulses on the 10 BASE-T medium from the PHY transmitter at Station B.
Efforts are underway to develop an architecture that enables computers to be linked together using conventional twisted pair telephone lines instead of established local area network media such as 10 BASE-T. Such an arrangement, referred to herein as a home: network environment, provides the advantage that existing telephone wiring in a home tray be used to implement a home network environment. However, telephone lines are inherently noisy due to spurious noise caused by electrical devices in the home for example dimmer switches, transformers of home appliances, etc. In addition, the twisted pair telephone litter suffer from turn-on transients due to on-hook and off-hook and noise pulses from the standard POTS telephones, and electrical systems such as heating and air conditioning systems, etc.
An additional problem in telephone wiring networks is that the signal condition (i.e., shape) of a transmitted waveform depends largely to the wiring topology. Numerous branch connections in the twisted pair telephone line medium, as well as the different associated lengths of the branch connections, may cause multiple signal reflections on a transmitted network signal. Telephone wiring topology may cause the network signal from one network station to have a peak-to-peak voltage on the order of 10 to 20 millivolts, whereas network signals from another network station may have a value on the order of one to two volts. Hence, the amplitude and shape of a received pulse may be so distorted that recovery of a transmit clock or transmit data from the received pulse becomes substantially difficult.
An additional problem encountered in European telephone systems involves the use of a network termination basic access (NTBA) device, used as an interface between the residential customer premises and a central office of the public switched telephone network for transmission of Integrated Services Digital Network (ISDN)-based signals. In particular, NTBA devices map a two-wire ISDN signal from a central office into a 4-wire S0 bus having a 2-wire send path and a 2-wire receive path for sending and receiving the ISDN-based signals throughout a customer premises. The ISDN-based signals generate harmonic reflections on the S0 bus that cause substantial interference with the higher-frequency network signals. Moreover, the zero crossing of as ISDN-based signal interferes substantially with the transmitted network signals rendering the transmitted network signal unusable due to the harsh conditions on the 4-wire S0 signal bus.
There is a need for an arrangement for interconnecting computer end stations in a home telephone network having a network termination basic access (NTBA) device and configured for sending ISDN-based signals on a 4-wire bus.
There is also a need for an arrangement for implementing a home computer network in ISND-bases customer premises configured for sending and receiving ISDN-based signals on a 4-wire S0 bus.
These and other needs are attained by the present invention, where a low pass filter is coupled to a 2-wire send path for attenuation of harmonics of ISDN-based signals that interface with transmitted network data signals. The low pass filter also delays the ISDN-based signals relative to the network data signals to minimize interference by the ISDN-based signal.
According to one aspect of the present invention, a method is provided of implementing a local area network is a hone telephone network having a network termination basic access (NTBA) device, configured for sending and receiving ISDN-based signals to and from a public switched telephonic network, and a four-wire bus including a two-wire send path and a two-wire receive path for sending and receiving the ISDN-based signals, respectively, between the NTBA device end taps along the four-wire bus. The method includes connecting a low pass filter, configured for passing the ISDN-based signals and rejecting harmonics thereof, between the two wires of the two-wire send path, and transmitting network data signals having frequencies substantially higher than the ISDN-based signals, between the taps.
According to another aspect of the present invention, a computer network includes a network termination basic access (NTBA) device, configured for sending and receiving ISDN-based signals to and from a public switched telephone network, a four-wire bus a two-wire send path and a two-wire receive path for sending and receiving the ISDN based signals between the NTBA device and ISDN customer premises equipment, first and second end stations configured for exchanging network data signals, having frequencies substantially higher than the ISDN-based signals, via at least one of the two-wire send path and the two-wire receive path, and a low pass filter. The low pass filter is coupled to the two-wise sand path for passing the ISDN-based signals and filtering harmonic signals of the ISDN-based signals substantially at the frequencies of the network data signals, the low pass filter enabling transmission of the network data signals via the at least one of the two-wire send path and the two-wire receive path.
Additional advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Apparatus and method of implementing a home network by filtering ISDN-based signals within the customer premises


In a turbine housing of a twin entry type turbocharger, a first scroll chamber communicating with a first exhaust manifold, and a second scroll chamber communicating with a second exhaust manifold are provided. A surface area of the first exhaust manifold is configured to be larger than a surface area of the second exhaust manifold, and these exhaust manifolds are cooled by a cooling mechanism. In the turbine housing, a first and second cooling water passages are respectively provided to cover the first and second scroll chambers. An internal combustion engine includes a cooling device that causes cooling water to flow into the first and second cooling water passages, and the cooling device is configured so that a temperature of the cooling water that is introduced into the second cooling water passage becomes lower than a temperature of cooling water that is introduced into the first cooling water passage.

Conventionally, Patent Literature 1, for example, discloses an art relating to an internal combustion engine including a twin entry type turbocharger. A twin entry type turbocharger includes two introduction ports for exhaust gas in the turbine, and an exhaust passage is configured so that exhaust gas of a first cylinder group out of a plurality of cylinders is caused to flow into one of the introduction ports of the turbine, and exhaust gas of a second cylinder group is caused to flow into the other introduction port of the turbine.
Further, the system of Patent Literature 1 described above includes two different cooling systems for cooling the exhaust gas that flows in exhaust ports. More specifically, the exhaust gas that flows in an exhaust port of the first cylinder group is cooled by a cooling system with a low water temperature, and the exhaust gas that flows in an exhaust port of the second cylinder group is cooled by a cooling system with a high water temperature.
Following is a list of patent literatures which the applicant has noticed as background of the present disclosure.
Patent Literature 1: JP 2012-132337 A
Patent Literature 2: JP 2005-163626 A
Patent Literature 3: JP 2009-243277 A


The present invention relates to an arrangement and methods for protection against electrical interference in a control computer (1) adapted to control at least one external unit (2). The invention in characterized in that the control computer (1) comprises hardware modules (4) designed to personal computer standards. In addition at least one of the modules (4) is operatively connected to means (8) adapted to prevent at least the interference which is harmful to the modules from reaching the latter and vice-versa. The interference-preventing means (8) are further operatively connected to the external unit (2). The arrangement comprises means adapted to shield the modules and the connection between the modules and the interference-preventing means in order to prevent capacitive/inductive transmission of the interference. The means of shielding comprise an outer casing (5), essentially enclosing at least the modules and the connection between the modules and the interference-preventing means and shielding them against electromagnetic radiation, together with an inner casing (9) essentially enclosing at least one of the modules and shielding it against electromagnetic radiation.

The present invention relates to an arrangement for protection against electrical interference in a control computer. The present invention also relates to a method for protecting hardware modules forming part of a control computer against electrical interference and a method of protection against electrical interference emitted by a control computer comprising hardware modules.
Programmable industrial control systems have traditionally been made up from highly specialized hardware and software modules. In recent years, however, there has been increasing interest in also using the so-called personal computer or PC concept for industrial control and automation. This is due to the fact that the personal computer concept is associated with a number of advantages, such as modularity, flexibility, incomparable access to both software tools and hardware modules and high quality, together with well-developed standardization. Personal computers, however, are constructed on the basis of the requirements of an office environment and are therefore in many respects unsuitable for use in more exacting environmental conditions.
Firstly, contacts and other mechanical parts are often designed for an office environment and are not of sufficient mechanical and electrical quality for an industrial environment. Secondly, the mechanical and electrical design of hardware modules of personal computers is such that modules cannot be replaced during operation. This facility is extremely desirable in the case of industrial control in order to avoid having to shut down an entire production line in the event of a failure in a module. Furthermore the electrical design of hardware modules is often far too deficient for industrial use. The great majority of modules on the market lack basic electrical protection, which is always required in an industrial context in order to prevent the destructive or inconvenient effect of incident electromagnetic interference, whether line-conducted or transmitted through capacitance/inductance. Even if specially manufactured hardware modules are used with complete protection, the problem remains that interference is still given off in the vicinity of modules that do not have corresponding protection, which in turn leads to a risk of capacitive/inductive transmission of the interference. Furthermore the main components according to the PC concept are basically not designed to withstand the levels of interference that an industrial control system i s expected to withstand. By main components we mean here the CPU and the so-called PC bus for electrical communication between the CPU and the constituent hardware modules. The said hardware modules must therefore be protected from the risk of line-conducted or capacitive/inductive interference.
An hermetically sealed construction for use in difficult environmental conditions, especially in military environments, is described in U.S. Pat. No. 5,570,270. The construction comprises a personal computer and a casing containing printed circuit cards and is intended to protect the printed circuit cards from electromagnetic interference (EMI) and mechanical influences in the form of high accelerations.
The present invention is intended to produce an improved arrangement and methods compared to the prior art in a control computer for use, for example, in an industrial or medical environment, which provide a good compromise between good protection against interference on the one band and flexibility and interchangeability on the other.
This is made possible by an arrangement of the type stated in the introductory part, which is characterised in that the control computer comprises hardware modules designed to personal computer standards, in that at least one of the modules is connected by way of first leads to means adapted to prevent at least the line-conducted interference, which is harmful to the modules, from reaching the latter, in that the interference-preventing means are connected by way of second leads to the external unit and that the arrangement comprises means adapted to shield the modules and the connection between the modules and the interference-prevent means in order to prevent capacitive/inductive transmission of the interference, the said means of shielding comprising an outer casing, essentially enclosing at least the modules and the connection between the modules and the interference-preventing means and shielding them against electromagnetic radiation, together with an inner casing essentially enclosing at least one of the modules and shielding it against electromagnetic radiation.
This has also been made possible by means of methods of the type stated in the introductory part, which are characterised in that at least the signals from the external unit to each module are made to pass through interference-preventing means, which prevent the signal interference that is harmful to the modules from reaching the latter, that the control computer is essentially enclosed by an outer casing, shielding it against interference in the form of electromagnetic radiation, and that the hardware modules are essentially enclosed by an inner casing shielding them against the said electromagnetic interference, in which the parts of the control computer that are located inside the inner casing are designed in accordance with a personal computer standard and the parts of the control computer that are located outside the inner casing are designed in accordance with a standard for use in some industrial environment, for example DIN. The casings are adapted both to protect the modules from external electromagnetic radiation and to protect the surroundings from electromagnetic radiation that is emitted by the modules. In addition the signals from each module to the external unit can also be made to pass through the interference-preventing means, which prevent signal interference in excess of a certain energy level from passing.
The present invention has a number of improvements on the prior art. Among other things, shielding against electromagnetic radiation is produced in two stages, which function even in environments very susceptible to interference, for example hospital environments, where interference from and by equipment located in the vicinity is entirely unacceptable. In addition high energies are prevented from reaching the unshielded parts of the control computer by way of the leads. Furthermore the method and the arrangement according to the invention are, for example, suitable for use in the control and automation of various processes in industry. Valuable advantages in this and other contexts include the fact that the arrangement according to the invention can be manufactured at relatively low cost, due among other things to the use of standard components and the simplicity of the arrangement, and to the fact that it is possible to replace components during operation.

Electrical interference protection arrangement for embedded control computers


It is an object of the present invention to provide a method for producing β-glucan having excellent immunopotentiating effects at a lower cost. Black yeast (Aureobasidium pullulans) is cultured using cells of lactic acid-producing bacteria and/or derivatives thereof as a nutrient source and is allowed to produce β-glucan.

Recently, β-glucan (β-1, 3-1, 6-glucan) attracts attention due to its immunopotentiating effects. That is, β-glucan serves to activate macrophages, NK cells, T cells, killer T cells and the like that attack infected cells and cancer cells in the body, and exhibits effects of eliminating bacteria and foreign matter that have entered the body and suppressing the onset of disease by increasing immunity and resistance. Also, it has been reported that as a result of exhibiting these effects, β-glucan has functions such as suppressing allergies, suppressing malignant tumors such as cancer, reducing blood sugar levels, promoting urination, adjusting blood pressure, and reducing blood cholesterol levels and neutral lipid levels.
As methods for producing β-glucan, a method for extracting β-glucan from baker's yeasts and mushrooms, and a method in which black yeast (Aureobasidium pullulans) is cultured to accumulate β-glucan in the culture medium, are used. It is considered that β-glucan derived from black yeast has higher water solubility than β-glucan derived from other organisms, and has the advantage of being highly effective due to its molecular structure in which the 1.6 chain is densely branched.
The immunopotentiating effects of lactic acid bacteria and of lactic acid-producing bacteria belonging to the genus Bacillus have already been known, and there are many reports thereupon. It is known that these bacteria producing lactic acid have relatively many specific base sequences (DNA fragments) called CpG motifs as components of their cell walls. It is conceivable that the CpG motifs directly stimulate the immune system of mammals to activate macrophages, NK cells, T cells, killer T cells and the like, and to enhance their defense systems against various types of infections.
It should be noted that the term "lactic acid bacteria" is not a bacterial name that is mycologically defined, and its definition is derived from the application of the family name Lactobacteriaceae to gram-positive bacilli and cocci that ferment sugar to produce only lactic acid or to produce lactic acid, acetic acid, alcohol, and carbonic acid gas.
Moreover, lactic acid-producing bacteria belonging to the genus Bacillus are sometimes called spore-forming lactic acid bacteria, but are not classified as common lactic acid bacteria.
Physiologically active effects of Bacillus coagulans have also been widely known, and its usefulness in probiotics has been found. Moreover, the safety of this bacterial strain is also as widely recognized as the safety of common lactic acid bacteria is (Non-Patent Documents 1 and 2).
A finished product in which β-glucan and lactic acid bacteria are mixed in a combination has been developed, and it is reported that in particular, a composition in which β-glucan and Enterococcus faecalis, which is a lactic acid coccus, are combined exhibits effects for enhancing immunity to influenza and preventing the exacerbation thereof (Patent Document 1).


An apparatus and method for measuring the water level at the bottom of a storage tank, the water level being the product-water interface between product and water within the storage tank. The apparatus includes a sensor assembly which is located at the tank bottom. The assembly has a plurality of measurement sensors arranged in a housing having slots for product and water to enter and leave the housing. Each measurement sensor is an open-circuited co-axial transmission line with a probe at its open end which functions as a monopole antenna. In preferred embodiments, the transmission lines are quarter wavelength open-circuited coaxial transmission lines. Each probe is located at a different distance from the tank bottom to cover a measurement range. The transmission lines are excited with signals which are reflected by the probes. As the level of the product-water interface changes on the probes, the capacitance of the probes also change which, in turn, change the amplitude or voltage level of the reflected signals. The voltage measurements are converted to level by a microprocessor.

1. Field of the Invention
The invention relates to an apparatus for interface measurement in a storage tank. In particular, the invention relates to an apparatus for continuously monitoring the water level at the bottom of a product storage tank.
2. Description of the Related Art
Many methods and techniques exist to detect an interface between product and water (herein referred to as a product-water interface), but due to the abrupt change in dielectric constant, capacitance techniques are most commonly employed. The drawback with using capacitance is that to provide adequate resolution, precise measurements are often necessary. This necessitates either careful circuit design or sophisticated signal processing which can be expensive and complex to implement.
Further, it is known to apply a co-axial transmission line to determine liquid-level in a tank. Electrical pulses are applied at the, line input. Changes in dielectric constant that result from the interface, cause the pulses to be reflected back to the line-input and from the measured reduction in pulse length, the liquid level is calculated. However, the measurement accuracy of this known system is limited by the need to make precision high speed measurements.

Apparatus for interface measurement in a storage tank


A suspension system for a vehicle includes a wheel carrier for rotatably supporting a wheel, an upper control link having a first end coupled to an upper end of the wheel carrier and a second end proximal to a vehicle body, a lower control link having a second end coupled to a lower end of the wheel carrier and a second end proximal to the vehicle body, a reciprocating hydraulic actuator disposed such that its reciprocating motion becomes perpendicular to a vertical direction of the vehicle body, a converter for converting the reciprocating motion of the reciprocating hydraulic actuator into an up-and-own motion of the upper and lower control links, and an electronic control part for controlling an operation of the reciprocating hydraulic actuator in accordance with a driving condition of the vehicle.

(a) Field of the Invention
The present invention relates to a suspension system for a vehicle and, more particularly, to an active suspension system for a vehicle which assumes an optimal geometrical shape depending on the driving state.
(b) Description of the Related Art
Generally, conventional active control suspension systems are designed to control the roll and pitch of a vehicle body by detecting the same and forcing the vehicle body against the directions of the roll and pitch. To apply such force to the vehicle body, the suspension system requires the use of a high level of energy.
That is, when using hydraulic force, the mechanical energy W of a hydraulic actuator can be calculated using an equation as shown in the following: EQU W=F.multidot.S=.vertline.F.vertline..vertline.S.vertline.Cos.theta.
where, F is the actuator force, S is an actuator stroke, and .theta. is an actuating angle of the actuator with respect to a vertical direction of the vehicle.
In a conventional active suspension system, as is well known, since the hydraulic actuator is disposed in a vertical direction with respect to the vehicle body, a great amount of mechanical energy needs to be exerted by the actuator to support the vehicle body. Even when the actuator is not mechanically operating in a state where no roll and pitch is applied to the vehicle, mechanical energy for supporting the vehicle against outer force is required.
Therefore, to apply such a great amount of mechanical energy, a high capacity hydraulic pump, a highly precise actuator, and various valves are required, complicating the suspension system, enlarging the size of the same as well as increasing manufacturing costs.


The cartridge has a memory for containing an information set, a status flag and a buffer for receiving an update to the information set, the update representing a change to only a part of the information set, and a data and power connector for connecting the cartridge to a host computer, the connector being able to receive power from the host computer and exchange data when connected to the host computer. The cartridge includes a power supply election switch including a battery for selectively supplying power from the host computer when the connector is connected and from the battery when disconnected. The update is transferred to the buffer and subsequently from the buffer to the information set in response to the status flag, such that in the event of a disconnection, while the update is being received, the information set is not partially updated. The cartridge may also include a real time clock and a copy of the time when the real time clock was set by the host in the memory, so that the host may use the clock setting of the real time clock if the copy of the time when the real time clock was set is more recent than the time when a clock on the host was set, such that when the cartridge is used between a plurality of host computers, a more accurate and recent clock setting may be transferred between the plurality of host computers by the cartridge.

Portable battery back-up data cartridges are commonly used for recording and transferring data between host computers, and more particularly between a field host computer and a base host computer.
An example of a computer system involving a field computer and a base computer with a data cartridge transferring information between the field and the base computers is given in U.S. Pat. No. 4,258,421 (Juhasz et al.), wherein a vehicle monitoring and recording system is disclosed. In such an environment, where the data recorded on the data cartridges includes parameters which undergo continuous updating (such as distance, fuel consumption, speed, RPM, battery voltage, oil pressure, fuel filter, cooling pressure, air pressure, brake temperature, cooling temperature, fuel temperature, and oil coolant level), it is important that the update of the data on the data cartridge be completed before the data cartridge is disconnected. In the case of an environment such as the cab of a semi-trailer truck, the data cartridge may be disconnected at any random time and it is important to prevent a partial update of the data contained on the data cartridge, as this can produce inconsistencies in the data recorded thereon.
Previous data cartridges concerned themselves with protecting the information which was being written at the moment of physical disconnection, by using connector pins that disconnected in a fixed mechanical sequence. For example, shorter pins which are disconnected first provide an early warning signal that a disconnection is imminent. It is also known that once the advent of a power failure is detected, means can be provided to switch to a battery backup power supply for keeping the memory in the cartridge alive while disconnected. An example of such a cartridge memory protection system is described in U.S. Pat. No. 4,607,351 (Gerber et al.).
Previous data cartridges do not concern themselves with the fact that multiple-byte records may be required to update the data structure held in the cartridge memory.
It is also important in computer processing environments, where the keeping of an accurate clock time is important, that the updating of real time clocks used in the field host computers be updated consistently with respect to the base host computers. The prior art data cartridges do not provide for the inclusion of a real time clock that can be utilized for field system real time clock updating, where the field system is able to select the freshest or most accurate time presented to it by any one of several cartridges presented to it.


A process for the preparation of a compound of the formula:

The present invention relates to a novel process for the preparation of compounds of the general formula
in which R, R2, R3 and R4 have the meaning below.
Compounds of the formula I are important intermediates for the preparation of pharmaceutically active compounds, for example of HMG-Co A reductase inhibitors. Japanese Patent publication JP-A 06 256318, and Watanabe M. et al., Bioorg. Med. Chem. 1997, Vol. 5, No. 2, 437-444 describe processes for the preparation of compounds of the formula I.
The process described in JP-A 06 256318 has the disadvantage that three stages are needed in order to prepare 2-amino-4-(4-fluorophenyl)-6-isopropyl-pyrimidine-5-carboxylic acid.
A process for the preparation of ethyl 4-(4-fluorophenyl)-6-isopropyl-2-(N-methanesulphonyl-N-methylamino)pyrimidine-5-carboxylate has been described by Watanabe M. et al., Bioorg. Med. Chem. 1997, Vol. 5, No. 2, 437-444. In this process, in the first stage p-fluorobenzaldehyde is converted using ethyl iso-butyrylacetate into an unsaturated ketoester, which is then cyclocondensed in the second stage with S-methylisothiourea hydrogensulphate and subsequently dehydrated in the third stage to give the corresponding pyrimidine. In the fourth stage, this is then oxidized using m-chloroperbenzoic acid to give the corresponding sulphonylpyrimidine, which is then reacted in the fifth stage with methylamine and subsequent treatment with methanesulphonyl chloride to give ethyl 4-(4-fluoro-phenyl)-6-isopropyl-2-(N-methanesulphonyl-N-methyl-amino)pyrimidine-5-carboxylate.
It is disadvantageous in this process, on the one hand, that many reaction stages are necessary and, on the other hand, that the desired product is only formed in moderate yield.
The object of the invention was to make available an economical, industrially feasible process for the preparation of compounds of the formula I.
The object of the invention is achieved by the novel process according to the process of the invention.
According to the invention, compounds of the general formula
in which
R is hydrogen or a group of the formula xe2x80x94SO2R1;
R1 is C1-6-alkyl;
R2 is hydrogen or C1-6-alkyl;
R3 is C1-6-alkyl;
R4 is C1-6-alkyl,
are prepared in that, in a first stage, a compound of the general formula
in which R3 and R4 have the abovementioned meaning, is reacted in the presence of a Lewis acid with 4-fluorobenzonitrile to give a compound of the general formula
in which R3 and R4 have the abovementioned meaning, and in a second stage the compound of the formula III obtained is reacted with a compound of the general formula
in which R and R2 have the abovementioned meaning, to give the final product of the formula I.
xe2x80x9cC1-6-alkylxe2x80x9d is understood here and below as meaning linear and branched alkyl groups having 1-6 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl, sec-butyl, pentyl and its isomers and hexyl and its isomers.
The compounds of the formula II can be prepared according to Chem. Berichte 1958, 91, 759 or are commercially available organic synthetic chemicals.
4-Fluorobenzonitrile is a commercially available organic synthetic chemical.
The Lewis acid employed in the first stage is expediently an aprotic Lewis acid such as, for example, tin tetrachloride, titanium tetrachloride or aluminium chloride. Tin tetrachloride is preferably employed.
The first stage is expediently carried out in the presence of an organic solvent. The organic solvents employed can be, for example, aromatic hydrocarbons, chlorinated aromatic and aliphatic hydrocarbons. Aromatic hydrocarbons employed are preferably toluene, benzene or xylene. The chlorinated aromatic hydrocarbon employed is preferably chlorobenzene; the chlorinated aliphatic hydrocarbon employed is preferably 1,2-dichloroethane. Toluene and 1,2-dichloroethane are particularly preferably employed.
The reaction in the first stage is expediently carried out at a temperature from xe2x88x925 to 140xc2x0 C., advantageously at 60 to 100xc2x0 C.
After a reaction time of 30 min to 6 h and subsequent hydrolysis, the compounds of the formula III can be isolated by known methods such as, for example, by extraction or can be employed directly, without isolation, for the second stage. The intermediate (formula III) is preferably isolated.
Compounds of the formula III include cis and trans isomers.
In a second stage, a compound of the formula III is reacted with a compound of the formula IV to give the final product of the formula I.
The invention comprises, on the one hand, compounds of the formula I in which R and R2 are hydrogen. These compounds are prepared by reaction of compounds of the formula III with cyanamide.
The reaction with cyanamide is expediently carried out in the presence of an organic solvent, a mixture of water with an organic solvent or in water. Water is particularly preferably employed. Organic solvents employed are advantageously toluene or ethyl acetate. Organic solvents employed as a mixture with water are advantageously alcohols such as, for example, methanol, ethers such as, for example, dioxane or aromatic hydrocarbons such as, for example, toluene or N,N-dimethylacetamide.
The reaction with cyanamide is expediently carried out at a temperature of 10 to 120xc2x0 C., advantageously at 40 to 100xc2x0 C. The pH is expediently in a range from 3 to 9, advantageously in a range from 4 to 7. After a reaction time of, in total, 1 to 20 h, the compounds of the general formula I are obtained, which can be worked up according to known methods.
In a particular embodiment, 2-amino-4-(4-fluorophenyl)-6-isopropylpyrimidine-5-carboxylic acid esters of the general formula
in which R3 has the meaning indicated in formula I are prepared in that, in a first stage, an alkyl iso-butyrylacetate of the general formula
in which R3 has the meaning mentioned is reacted in the presence of a Lewis acid with 4-fluorobenzonitrile to give a 2-[1-amino-1-(4-fluorophenyl)methylene]-4-methyl-3-oxopentanoic acid ester of the general formula
and in a second stage the compound of the formula IIIa is reacted with cyanamide of the formula
in which R and R2 are hydrogen, to give the final product of the formula Ia.
The radical R3 is preferably methyl.
The compounds of the formula III are novel and also a subject of the invention.
The invention comprises, on the other hand, compounds of the formula I in which R is a group of the formula xe2x80x94SO2R1 and R1 and R2 are C1-6-alkyl. These 4-(4-fluorophenyl)-6-alkyl-2-(N-alkanesulphonyl-N-alkylamino)pyrimidine-5-carboxylic acid esters of the general formula
in which R1, R2, R3 and R4 are identical or different and are a C1-6-alkyl group, can be prepared in that 2-[1-amino-1-(4-fluorophenyl)methylene]-4-alkyl-3-oxo-alkanoic acid esters of the general formula
in which R3 and R4 have the abovementioned meaning, are reacted with N-cyano-N-alkylalkanesulphonamides, optionally isolated or prepared in situ, of the general formula
in which R1 and R2 are a C1-6-alkyl group.
The reaction can be carried out either in the presence of a base or in the presence of a Lewis acid.
Bases which can be employed are alkali metal compounds such as, for example, alkali metal hydrides, alkali metal carbonates, alkali metal alkoxides or alkali metal silazanes. Alkali metal carbonates which can be used are lithium, sodium or potassium carbonate. The alkali metal hydride employed can be potassium, lithium or sodium hydride; sodium hydride is preferably employed. The alkali metal alkoxide employed can be sodium or potassium tert-pentoxide or sodium or potassium tert-butoxide, preferably sodium tert-pentoxide or sodium tert-butoxide. The alkali metal silazane used can be sodium hexamethyldisilazane or potassium hexamethyldisilazane. The base preferably employed is an alkali metal hydride or an alkali metal alkoxide.
The reaction is expediently carried out in the presence of a base in a polar organic solvent. The polar solvent used can be, for example, N,N-dimethyl-acetamide, isopropanol, tert-butanol, toluene, di-methylformamide, tetrahydrofuran, 1,4-dioxane or mixtures of these. N-Alkylalkanesulphonamides such as, for example, N-methylmethanesulphonamide are likewise suitable as solvents. The reaction is preferably carried out in N-alkylalkanesulphonamide and tert-butanol.
The reaction can be carried out in the presence of a base at a temperature from xe2x88x9210 to 150xc2x0 C., preferably from 0 to 80xc2x0 C.
The reaction of compounds of the formula IIIb with compounds of the formula IVb in the presence of a Lewis acid is expediently carried out in the solvent which is inert to the Lewis acid. Inert solvents which can be employed are, for example, aromatic hydrocarbons, and chlorinated aromatic and aliphatic hydrocarbons. Aromatic hydrocarbons employed are preferably toluene or xylene. The chlorinated aromatic hydrocarbon employed is preferably chlorobenzene; chlorinated aliphatic hydrocarbons employed are preferably dichloromethane or 1,2-dichloroethane.
The reaction in the presence of a Lewis acid can be carried out at a temperature from 20 to 150xc2x0 C., preferably from 80 to 120xc2x0 C.
Suitable Lewis acids are for example TiCl4, TiBr4 or SnCl4. Titanium tetrachloride is preferred.
The amount of Lewis acid is 0.1 to 2 molar equivalents based on the compound of the formula IIIb.
After a reaction time of 1 to 24 h, the final products of the general formula Ib can be isolated by known working-up methods.
In a preferred embodiment, the final product of the formula Ib isolated is ethyl 4-(4-fluorophenyl)-6-isopropyl-2-(N-methanesulphonyl-N-methylamino)-pyrimidine-5-carboxylate (R1=R2=R3=methyl, R4=isopropyl).
Compounds of the formula IVb are expediently prepared in that a compound of the general formula
in which R1 and R2 are C1-6-alkyl, is reacted with cyanogen halide in the presence of a base.
Suitable bases are the bases described beforehand.
The cyanogen halide employed can be cyanogen fluoride, cyanogen chloride, cyanogen bromide or cyanogen iodide. Cyanogen chloride or cyanogen bromide is preferably employed.
This reaction can likewise be carried out in the polar organic solvents described beforehand. The reaction is preferably carried out in tetrahydrofuran.
The reaction is expediently carried out at a temperature from xe2x88x9220 to 50xc2x0 C., preferably at a temperature from xe2x88x9210 to +20xc2x0 C.
After a reaction time of xc2xe to 1 h, the compounds of the formula IVb, which have not yet been described in the literature, can then be isolated in a manner known to the person skilled in the art.
These compounds of the formula IVb are also a subject of the invention.
Compounds of the formula IVb can be prepared in situ, i.e. they are formed directly from the corresponding starting materials during the reaction without isolation. However, they can also be prepared and isolated separately in order then to employ them for the reaction.
Examples of compounds of the formula IVb are: N-cyano-N-methylmethanesulphonamide, N-cyano-N-ethyl-methanesulphonamide, N-cyano-N-propylmethanesulphonamide, N-cyano-N-butylmethanesulphonamide, N-cyano-N-pentylmethanesulphonamide and N-cyano-N-hexylmethanesulphonamide. N-Cyano-N-methylmethanesulphonamide is preferred.
The compounds of the formula I can also be prepared in that a compound of the general formula
in which R3 and R4 have the meaning mentioned in claim 1, is reacted with a compound of the formula IV.
The reaction is carried out analogously to the reaction of the compounds of the formula III with compounds of the formula IV, preferably in the presence of a base in a polar organic solvent at a temperature from xe2x88x9210 to 150xc2x0 C.
Suitable bases and solvents correspond to the bases and solvents which are listed under the reaction of compounds of the formula III with compounds of the formula IV.
In a preferred embodiment, compounds of the general formula Ib are prepared in that a compound of the formula VI is reacted with a compound of the formula IVb in a polar organic solvent at a temperature from 0 to 80xc2x0 C. in the presence of a base.
The compounds of the formula VI can be prepared by reaction of C1-6-alkyl nitriles with C1-6-alkyl 4-fluorobenzoylacetate in the presence of a Lewis acid. A compound of the formula VI in which R3 is methyl and R4 is isopropyl is preferred. The Lewis acid is preferably tin tetrachloride. The reaction is expediently carried out in a polar solvent. Suitable solvents correspond to the solvents which are listed under the reaction of compounds of the formula II with compounds of the formula III described above. The reaction in the first stage is expediently carried out at a temperature from xe2x88x925 to 140xc2x0 C., advantageously at 60 to 100xc2x0 C.
The compounds of the formula VI are novel and likewise a subject of the invention.

Process for preparing 2-amino-4-(4-fluorphenyl)-6-alkylpyrimidine-5-carboxylate

Abstract: wherein the variables are herein below defined.


A waterbed mattress has a watertight envelope having a top, a bottom and sides. The envelope defines a cavity for water. First and second valves are disposed in the envelope to selectively allow fluid communication between the cavity and the exterior of the envelope. The second valve is spaced from the first valve. Pump structure is operatively connected to the first and second valves for selectively evacuating water from the cavity. The pump structure includes a venturi member which operates inside the envelope to evacuate water from the envelope.

This invention relates to waterbeds and more particularly to draining the water from waterbed mattresses.
Waterbed mattresses are known to provide many advantages in terms of comfort and restfulness. However, these mattresses are relatively heavy. As a result, from time to time it may become necessary to drain a waterbed mattress (when it is desired to move the waterbed to a new location, for example).
Conventionally, this has been done using a siphon device based in part on the venturi principle. This siphon device, called a drain pump or adapter is a separate plastic part which attaches to a water faucet. This adapter includes three ports. One is attached to the water faucet, one is a drain port, and the third is adapted to attach to a conventional garden hose. In use the other end of the garden hose is attached to the drain/fill valve of the waterbed mattress.
Water from the faucet flows through the adapter and, by means of the venturi effect, generates a partial vacuum in the adapter by the third port. This vacuum thereby acts through the garden hose to evacuate water from the waterbed mattress.
These conventional drain pumps can be improved. For example, these pumps are a separate piece which is relatively small and easily lost. It is quite common for the drain pumps to be lost because mattresses are drained relatively infrequently. In addition, since the drain/fill valve of the waterbed mattress is conventionally on the top of the mattress, the presently available drain pumps have difficulty draining the mattresses completely. Water in the bottom of the mattress or in anti-wave material such as fiber batting inside the mattress is very difficult to remove since the conventional drain pumps must work against gravity or similar forces to remove the water. As a result, the waterbed mattress, even when drained, retains so much water that it is still relatively heavy and somewhat difficult to pumps take an undesirably long time to drain a waterbed mattress.


A catalyst for treatment of exhaust emissions from diesel engines includes a washcoat layer with a catalytically active metal. The washcoat layer has refractory oxide particles with catalytically active metal particles dispersed thereon, and colloidal silica disposed in a thin layer over the refractory oxide and metal particles. The refractory oxide particles and colloidal silica are each characterized by respective surface charges at a selected pH to cause the colloid to form the layer over the refractory oxide and metal particles. Preferably, the pH is selected to provide opposite and attractive surface charges between the colloidal silica and the refractory oxide particles. Preferably, the metal particles are at least one of the group consisting essentially of platinum, palladium, rhodium, ruthenium, copper and chromium.

Exhaust emissions from an engine, such as in a vehicle, are treated in a catalytic converter which includes catalytic material dispersed on a support. In order to treat vehicle exhaust gas emissions, the support typically includes a metal or ceramic base, which is coated with a refractory oxide or ceramic material, such as alumina. The catalytic material carried by the support promotes oxidation of unburned or partially oxidized hydrocarbons and carbon monoxide and promotes the reduction of nitrogen oxides. In the case of diesel engines, it is necessary to treat diesel particulates which are typically on the order of 0.1 micron in diameter and contain a solid, carbonaceous portion and a soluble organic portion.
Diesel particulate can be collected and removed from an exhaust gas stream by various types of filters or traps. In order to remove collected particulate, the traps are heated to an elevated temperature, which is greater than the exhaust temperature, by heaters. This approach to treating particulate is technically difficult and costly, and introduces a variety of other undesirable problems.
It is desirable to treat diesel particulate by continuous catalytic combustion of particulate in the exhaust gas stream over a catalyst in a catalytic converter in a method similar to the treatment of gaseous hydrocarbon emissions. Converters using substrates coated with alumina, such as alumina-coated monoliths, have been evaluated for this purpose. However, such alumina-coated supports promote an undesirable reaction with sulfur which is present in a relatively large amount in diesel fuels as compared to gasoline.
Silicas have been used as catalyst supports but have not been favored for use with vehicles due to the high temperature of operation of the vehicle, the relatively low thermal stability of silica as compared to alumina, and the relatively low adherence of silica to a base substrate.
In order to improve adherence of silica, U.S. Pat. No. 5,114,901 issued May 19, 1992, assigned to the assignee of the present application, describes a support consisting of two groups of silica particles of non-overlapping sizes where one group occupies voids between the other group when applied as a washcoat layer (catalyst support). Catalytic metal is dispersed on the outer surface of the applied washcoat layer (post-impregnation). Although the washcoat layer of U.S. Pat. No. 5,114,901 provides improved adherence and reduced reaction with sulfur, further improvement is desirable.

Catalytic washcoat for treatment of diesel exhaust